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April 2011

04/26/2011

STAYING MILD, BUT MORE UNSETTLED

WE CERTAINLY ARE DEALING WITH A VERY ACTIVE WEATHER PATTERN IN THE EASTERN HALF OF THE U.S.! THERE ISN'T ONE TIME PERIOD FROM TONIGHT THROUGH FRIDAY THAT WE CAN GUARANTEE DRY WEATHER HERE. HOWEVER, IT STILL APPEARS THAT OUR BEST SHOT AT GETTING STRONG AND PERHAPS SEVERE T-STORMS WILL COME ON THURSDAY, GIVEN THE CURRENT PROJECTED TIMING OF THE COLD FRONTAL PASSAGE.

IN THE MEANTIME, THE AIR MASS OVER US IS QUITE WARM, AND IT IS ALSO GETTING QUITE "JUICY" WITH THE HIGHEST DEW POINTS THAT WE HAVE SEE IN A LONG TIME NOW OVERSPREADING THE REGION. AS OF THIS WRITING, ONE SEVERE T-STORM BOX IS IN EFFECT FOR PORTIONS OF UPSTATE NY, AS WELL AS IN PA MAINLY NORTH AND WEST OF A LINE FROM THE NORTHERN POCONOS DOWN TO HARRISBURG AND CHAMBERSBURG. ANOTHER BOX IS OUT FOR A GOOD CHUNK OF WV AND WESTERN VA. WE DEFINITELY HAVE TO KEEP A CLOSE EYE ON THE RADARS THIS EVENING AND WATCH FOR A FEW STRONG OR HEAVY T-STORM CELLS MAKING PROGRESS FARTHER EASTWARD.

AT THE SAME TIME, ALMOST TROPICAL AIR IS PUSHING NORTHWARD INTO THE EASTERN CAROLINAS, SOUTHEAST VA, AND THE SOUTHERNMOST TIP OF THE DELMARVA PENINSULA. DEW POINTS DOWN THAT WAY ARE NEAR AND ABOVE 70 IN MANY LOCATIONS. THAT AREA HAS TO BE MONITORED CAREFULLY TONIGHT TO SEE HOW FAR NORTH THE MOISTURE PUSHES.

AS WE HEAD INTO TOMORROW, THERE IS NO DOUBT THAT WE WILL CONTINUE TO BE IN THE WARM SECTOR. HOWEVER, ALL INDICATIONS ARE THAT IT WILL BE A PRETTY "DIRTY" WARM SECTOR WITH LOTS OF MOISTURE AROUND. SOME MODEL SOUNDINGS ARE MORE MOIST LOOKING THAN OTHERS. AS A RESULT, WE HAVE NO CHOICE BUT TO LEAN OUR FORECAST MORE TOWARD CLOUDS THAN SUN TOMORROW. OUR SURFACE WIND FLOW TOMORROW WILL BE AT LEAST DUE SOUTHERLY, AND COULD EVEN BE A BIT EAST OF DUE SOUTH. THESE ABOVE FACTORS COMBINED WILL MOST LIKELY RESULT IN AT LEAST SLIGHTLY LOWER TEMPS THAN TODAY. WE ARE STILL ABOVE NUMBER GUIDANCE TOMORROW, BUT IF IT DOES ENDUP BEING CLOUDY MUCH OF THE DAY, THEN WE ARE TOO HIGH. WITH A MOIST AIR MASS IN PLACE TOMORROW AND TOMORROW NIGHT, IT WOULDN'T TAKE TOO MUCH TO TRIGGER A SHOWER OR T-SHOWER. HOWEVER, AS WE SAID BEFORE, OUR BEST SHOT AT MORE WIDESPREAD AND ORGANIZED T-STORMS, AND EVEN SEVERE WEATHER, WILL BE ON THURSDAY AS HEIGHTS FALL INTO THE STICKY AIR AND THE SURFACE COLD FRONT ARRIVES. WE WILL LOOK AT THURSDAY'S SITUATION MORE CAREFULLY IN LATER DISCUSSIONS. THE BOTTOM LINE IS THAT EVEN IF WE DON'T GET DAMAGING WINDS AND HAIL WITH THE T-STORMS ON THURSDAY, THERE ALMOST CERTAINLY WILL BE LOCALLY HEAVY RAIN, GIVEN THE HIGH PRECIPITABLE WATER AMOUNTS THAT DAY.

BEHIND THE FRONT, FRIDAY LOOKS COOLER, ALTHOUGH THE COOLEST AIR WILL PROBABLY HANG BACK SOMEWHAT WITH THE AXIS OF THE UPPER LEVEL TROF. WITH LOW HEIGHTS AND CHILLY AIR ALOFT ON FRIDAY, WE DO EXPECT INSTABILITY CLOUDS TO FORM, AND THERE MAY ALSO BE A BRIEF AFTERNOON OR EVENING SHOWER. THE START OF THE WEEKEND LOOKS NICE ON SATURDAY, AND THAT DRY WEATHER WILL PROBABLY CARRY OVER INTO AT LEAST PART OF SUNDAY.

04/14/2011

FINE LOOKING FRIDAY FOLLOWED BY A SOAKING SATURDAY NIGHT

RIGHT ON TARGET, TODAY TURNED OUT TO BE A REAL GEM OF A SPRING DAY! TEMPS RECOVERED NICELY TODAY, DESPITE THE WET GROUND FROM THE RECENT RAINS. A WEAK, MOISTURE-STARVED COLD FRONT IS PRESSING SOUTHWARD. THERE IS NO PRECIP WITH THIS FRONTAL BOUNADRY...JUST PATCHY CLOUDS AND A SUBTLE WIND SHIFT. YOU CAN SEE THIS FRONT ON THE LATEST SATELLITE LOOP. OVERALL, OUR WEATHER LOOKS PRETTY NICE AROUND HERE THROUGH TOMORROW AS A LARGE HIGH PRESSURE SYSTEM BUILDS EASTWARD FROM ONTARIO INTO QUEBEC. THERE WILL BE A FEW CLOUDS AROUND AT TIMES TOMORROW, BUT NO BIG DEAL. AT LEAST IT WILL BE A DRY DAY. TEMPS TOMORROW LOOK 5-10 DEGREEA COOLER THAN TODAY. 

THE FORECAST FOR THE WEEKEND STILL SEEMS FINE. SATURDAY WILL BE A CHILLY DAY WITH A STRONG ONSHORE FLOW. THE ATMOSPHERE WILL MOISTEN UP AT ALL LEVELS ON SATURDAY...IN THE MID AND UPPER LEVELS DUE TO THE APPROACHING SYSTEM FROM THE WEST, AND IN THE LOWEST 5000 FEET OR SO FROM THE FLOW OFF THE OCEAN. BEFORE THE STEADY RAIN GETS HERE ON SATURDAY, IT CERTAINLY COULD BEGIN TO DRIZZLE FROM THE EASTERLY WINDS. IT APPEARS THAT THE STEADY RAIN WILL HOLD OFF UNTIL SOMETIME LATE SATURDAY AND THEN IT WILL RAIN HARD AT TIMES SATURDAY NIGHT. WITH A NEGATIVELY TILTED TROF ENCOUNTERING THE MOISTURE IN PLACE HERE, THE RESULT WILL BE SOME HEAVY RAIN ON OCCASION, ESPECIALLY SATURDAY NIGHT. WE ARE IN LINE FOR A GOOD SOAKING, WITH AT LEAST 3/4", AND THERE IS THE POTENTIAL FOR 1.0" TO 1.5" IN SPOTS. SINCE HEIGHTS WILL BE CRASHING HERE SATURDAY NIGHT, THERE COULD EVEN BE A FEW RUMBLES OF THUNDER!

BEHIND THIS SYSTEM, IT WILL DRY OUT ON SUNDAY WITH A WESTERLY, DOWNSLOPING WIND FLOW. LIKE WE SAID YESTERDAY, THERE REALLY WON'T BE ANY COOLING BEHIND THIS FRONT ON SUNDAY, AND IN FACT, THE FRONT WILL ESSENTIALLY BE A WARM OCCLUSION. THE AIR MASS BEHIND THE BOUNDARY WILL BASICALLY BE PACIFIC IN ORIGIN, AND SO SUNDAY WILL BE A MILDER DAY. LOOKING AHEAD TO THE EARLY TO MIDDLE PART OF NEXT WEEK, WE HAVE A CHALLENGING FORECAST AHEAD OF US, DEPENDING ON WHERE THE NEXT FRONTAL BOUNDARY SETS UP. IT IS BECOMING MORE AND MORE LIKELY THAT WE WILL BE SOUTH OF THE FRONT FOR AN EXTENDED PERIOD OF TIME. IF THAT IS INDEED THE CASE, THEN WE COULD EVENTUALLY GET VERY WARM, AND OUR HIGHS ARE STILL TOO LOW.

04/13/2011

ALMOST DONE WITH THE DREARY WEATHER

TODAY CERTAINLY TURNED OUT TO BE A DAMP, COOL DAY. CURRENTLY, LOW PRESSURE IS CENTERED ALONG THE SOUTHERN NJ COAST. THIS SYSTEM WILL SLOWLY TRACK NORTHEASTWARD TONIGHT, REACHING NEW BRUNSWICK BY TOMORROW MORNING. IF YOU GLANCE AT A RADAR LOOP, YOU CAN REALLY SEE WHERE THE UPPER LEVEL CLOSED LOW IS LOCATED. POCKETS OF RAIN AND SHOWERS CONTINUE TO ROTATE AROUND THIS LOW, AND WE WILL JUST HAVE TO KEEP A CLOSE EYE ON THE RADARS AS WE HEAD INTO THE EVENINGHOURS.

BY LATER TONIGHT, DRIER AIR AND SUBSIDENCE WILL TAKE OVER AND SKIES WILL AT LEAST PARTIALLY CLEAR. THAT WILL SET THE STAGE FOR A MUCH NICER DAY WEATHER WISE TOMORROW. WITH A RIDGE OF HIGH PRESSURE IN CONTROL OF OUR WEATHER TOMORROW, AND SURFACE WINDS AVERAGING NORTHWEST, WE EXPECT MORE SUNSHINE THAN CLOUDS AND A VERY NOTICEABLY UPTICK IN TEMPS. WITH THE MOIST GROUND, IT IS POSSIBLE THAT WE ARE A TAD TOO HIGH WITH OUR MAX TEMP PREDICTIONS TOMORROW. HOWEVER, WE DECIDED TO GIVE THEM EVERY CHANCE TO VERIFY, GIVEN THE TIME OF YEAR IT IS WITH A STRENGTHENING MID-APRIL SUN.

THE COLD FRONT PRESSING IN FROM THE NORTH TOMORROW AND TOMORROW NIGHT WILL BASICALLY BE NO CONCERN WHATSOEVER. WE EXPECT LITTLE OR NO EFFECT FROM THAT FRONTAL BOUNDARY, OTHER THAN A SUBTLE WIND SHIFT, A PRESSURE RISE, AND PATCHY CLOUDS. THIS LOOKS LIKE A CLASSIC SITUATION WHERE THE REAL COOLING BEHIND THE COLD FRONT WILL BE DELAYED FOR A SHORT TIME. THAT MEANS THAT EVEN THOUGH FRIDAY WILL BE COOLER THAN TOMORROW, IT WILL STILL BE A DECENT DAY WITH SOME SUNSHINE AND MORE OF A NORTHEAST BREEZE OVER LAND.

BY FRIDAY NIGHT, HOWEVER, THE WIND TRAJECTORY WILL SWING AROUND TO MORE EASTERLY, RIGHT OFF THE ATLANTIC OCEAN. THAT ONSHORE FLOW, COMBINED WITH THE MODIFIED ARCTIC AIR CIRCULATING SOUTHWESTWARD, WILL RESULT IN A VERY CHILLY FEEL HERE BY THE START OF THE WEEKEND. WE HAVE BEEN TRENDING TEMPS FOR SATURDAY DOWN THE PAST COUPLE OF DAYS, AND WE STILL MAY NOT BE LOW ENOUGH. HOWEVER, WE HAVE TO BE SOMEWHAT CAUTIOUS NOT TO OVERDO THINGS, GIVEN THE SLIGHTLY SLOWER ARRIVAL OF THE RAIN COMING IN FROM THE WEST. DRIZZLE COULD CERTAINLY BREAK OUT WELL AHEAD OF THE RAIN ZONE, GIVEN THE MOISTENING OCEAN FLOW. HOWEVER, IT NOW LOOKS LIKE THE MAIN BATCH OF RAIN WON'T GET HERE UNTIL SOMETIME LATE SATURDAY AFTERNOON OR MAYBE EVEN EARLY SATURDAY EVENING, AND THEN IT WILL RAIN FAIRLY HARD SATURDAY NIGHT. TEMPS ARE LIKELY TO DROP WITH THE ONSET OF THE RAIN, AS IT WET BULBS.

THE ONE THING THAT DEFINITELY LOOKS DIFFERENT TODAY COMPARED TO THE PAST COUPLE OF DAYS IS THAT THE CLOSED LOW BRINGING US THE RAIN THIS WEEKEND WILL OPEN UP AND LIFT OUT BY SUNDAY. THAT WILL LEAD TO MORE RAPID DRYING BEHIND THE SYSTEM. SINCE THE AIR MASS BEHIND THE OCCLUSION IS OF PACIFIC ORIGIN, TEMPS SHOULD RESPOND NICELY SUNDAY INTO MONDAY. WE HAVE STARTED THE UPWARD TREND IN TEMPS THOSE DAYS, AND WE STILL MAY NOT BE QUITE WARM ENOUGH.

04/11/2011

WARM WEATHER IS A ONE DAY WONDER

AFTER STRUGGLING THIS WEEKEND, THE WARM AIR IS FINALLY CHARGING IN WITH A VENGEANCE THIS AFTERNOON. WE ARE EXPERIENCING THE WARMEST WEATHER OF THE YEAR SO FAR! TEMPS ARE AT THEIR HIGHEST LEVEL SINCE LATE LAST SEPTEMBER. ON THE LATEST WEATHER MAP, WE SEE A COLD FRONT STRETCHING FROM THE ONTARIO-QUEBEC BORDER, DOWN ACROSS THE EASTERN GREAT LAKES REGION ANDTHE OHIO VALLEY AND INTO THE LOWER MISSISSIPPI VALLEY. AS OF THIS WRITING, THERE ARE TWO TORNADO BOXES OUT, AND IT IS POSSIBLE THAT ANOTHER BOX WILL BE ISSUED BEFORE TOO LONG. FARTHER NORTH, THERE HAVE ONLY BEEN SOME SCATTERED THUNDERSTORMS SO FAR FROM NORTHERN PA INTO UPSTATE NY AND NORTHERN NEW ENGLAND, ALTHOUGH MORE ARE SHOWING UP ON RADAR NOW. WE DO HAVE TO BE ON GUARD FOR T-STORM, A FEW LOCALLY STRONG, MOVING INTO OUR AREA LATER TONIGHT.

THIS WILL PROBABLY BE ONE OF THOSE SITUATIONS WHERE THE FARTHER SOUTH AND EAST YOU GO, THE MORE CHANCE T-STORMS WILL HAVE TO WEAKEN OVERNIGHT AS THEY PUSH ALONG WITH THE COLD FRONT. IN A NUTSHELL, THE TIMING JUST WON'T BE GREAT. TONIGHT WILL BASICALLY JUST BE AN HOUR BY HOUR NOWCAST, BASED ON THE LATEST RADARS AND SURFACE OBS. AT THIS JUNCTURE, THE SOUTHEASTERN EDGE OF THE SLIGHT RISK AREA FOR SEVERE T-STORMS RUNS FROM INTERIOR NEW ENGLAND INTO THE HUDSON VALLEY, DOWN ACROSS NORTHWEST NJ TO JUST NORTHWEST OF PHILLY, AND DOWN ACROSS THE NORTHERN PART OF THE CHESAPEAKE BAY. IT IS NOT TOO LIKELY THAT SPC WILL PUSH THIS ZONE FARTHER SOUTH AND EAST, ALTHOUGH THAT WILL HAVE TO BE WATCHED CAREFULLY.

BY TOMORROW, THE UPPER LEVEL TROF WILL BEGIN TO GET PINCHED OFF, AND WE'LL EVENTUALLY SEE A CLOSED LOW FORMING OVER SOUTHWESTERN VA DURING THE AFTERNOON HOURS. THAT, IN TURN, WILL CAUSE THE SURFACE FRONT TO SLOW DOWN CONSIDERABLY, AND EVENTUALLY STALL OUT. WHERE THE FRONTAL BOUNDARY EVENTUALLY COMES TO A GRINDING HALT WILL DETERMINE THE TRACK OF A SURFACE LOW THAT WILL FORM ALONG THE FRONT. THE BOTTOM LINE IS THAT WITH THE FORMATION OF AN UPPER LEVEL CLOSED LOW, THE PROGRESSION OF THINGS FROM TOMORROW THROUGH WEDNESDAY WILL BE RATHER SLOW. SO, WE EXPECT THE SHOWER/T-STORM REGIME TO GRADUALLY MORPH INTO A STEADIER RAIN PATTERN. OUR POTENTIALLY WETTEST PERIOD HERE WILL PROBABLY BE TOMORROW AFTERNOON AND NIGHT, WITH STILL SOME LINGERING RAIN INTO WEDNESDAY.

AS FOR RAINFALL TOTALS FROM THIS SETUP, IT LOOKS LIKE WE COULD GET A GOOD SOAKING WITH 1" OF RAIN, AND PARTS OF THE AREA COULD GET AS MUCH AS 1.25" OR MORE. TEMPS TOMORROW WILL BE NOTICEABLY COOLER THAN TODAY, AND WILL BASICALLY HOLD STEADY OR SLOWLY FALL FROM THE EARLY MORNING LEVELS. WEDNESDAY WILL BEAS COOL OR EVEN COOLER.

LOOKING AHEAD, MUCH NICER WEATHER WILL RETURN ON THURSDAY AS HIGH PRESSURE BUILDS IN. WE WILL STAY DRY ON FRIDAY, BUT THEN A VERY UGLY AND UNSETTLED PATTERN IS SHAPING UP FOR THE WEEKEND.

04/07/2011

WARM-UP WILL BE WORTH THE WAIT

 

 

ON THE CURRENT WEATHER MAP, WE SEE A NEARLY STATIONARY FRONT STRETCHING FROM THE MID-ATLANTIC COAST BACK INTO THE OHIO AND MID MISSISSIPPI VALLEY. A WARM, BERMUDA-TYPE HIGH IS CENTERED OFF OF THE SOUTHEAST COAST, AND ANOTHER HIGH IS LOCATED TO OUR NORTH OVER EASTERN ONTARIO AND QUEBEC. A WAVE OF LOW PRESSURE IS NOW PUSHING EASTWARD ALONG THE FRONTAL BOUNDARY. THAT SYSTEM WILL BE IN SOUTHERN IL OR IN BY TOMORROW MORNING, AND WILL SHIFT INTO SOUTHWESTERN VA OR NC BY EARLY TOMORROW NIGHT. BY 12Z SATURDAY, WE EXPECT THAT WAVE TO BE OFF THE NC COAST AND HEADING OUT TO SEA.

YESTERDAY, THERE WAS QUITE A BIT OF DIFFERENCE IN THE MODELS AS TO HOW FAR NORTH AND EAST THEY WERE BRINGING THE BATCH OF RAIN ASSOCIATED WITH THE LOW. NOW, THE GUIDANCE IS CLOSER TOGETHER, BUT THERE ARE STILL SOME DISCREPANCIES. WE FEEL THAT THE NORTHEASTERN EXTENT OF THE RAIN SHIELD WITH THIS FEATURE WILL EVENTUALLY SET UP FROM EXTREME SOUTHWESTERN NY STATE DOWN TO OR JUST SOUTH OF NYC. THE CORE OF THE MOST SIGNIFICANT RAIN WILL PROBABLY RUN FROM NORTHERN OH INTO PARTS OF WESTERN AND CENTRAL PA AND DOWN TO THE MID-ATLANTIC COAST. IN THAT WETTEST ZONE, IT APPEARS THAT RAINFALL TOTALS WILL BE IN THE 1/2" TO 3/4" RANGE. CLOSER TO HOME, WE EXPECT RAIN TO MOVE INTO THE AREA DURING THE LATE AFTERNOON, AND CONTINUE INTO TOMORROW NIGHT. RAINFALL TOTALS IN THE COVERAGE AREA COULD BE AS HIGH AS 1/3" SOUTH AND WEST OF THE CITY, BUT AS LOW AS NIL IN OR NOT TOO FAR TO THE NORTHEAST. JUST HOW QUICKLY IT MOISTENS UP TOMORROW AND HOW QUICKLY THE SOUTHEAST BREEZE KICKS IN WILL DETERMINE HOW HIGH THE TEMPS GO BEFORE LEVELING OFF AND FALLING BACK SOMEWHAT.

OVER THE WEEKEND, WE WILL STRUGGLE WITH AN EASTERLY COMPONENT TO THE WIND FLOW FOR AWHILE. THAT WILL HOLD BACK THE UPWARD TREND IN TEMPS. IN A WORSE CASE SCENARIO, WE WILL HAVE TO DEAL WITH LOW CLOUDS, DRIZZLE, AND FOG FOR A TIME THIS WEEKEND. IF THE WARM FRONT DOES INDEED MOVE THROUGH ON SUNDAY, THEN MUCH, MUCH WARMER AIR WILL BEGIN TO WORK ITS WAY INTO THE REGION. THE LATEST GUIDANCE IS SUGGESTING THAT THE BEST FORCING FOR WARM ADVECTION SHOWERS AND T-STORMS WILL BE TO OUR NORTH AND NORTHWEST...RUNNING FROM NORTHEAST OH AND NORTHERN PA INTO UPSTATE NY. EVEN SO, THERE COULD BE A SHOWER OR T-STORM HERE AT SOME POINT ON SUNDAY.

WE STILL FEEL THAT MONDAY WILL BE OUR BLOW TORCH DAY, AHEAD OF THE NEXT COLD FRONT. WE HAVE BEEN TRENDING TEMPS THAT DAY UPWARD DURING THE PAST COUPLE OF DAYS. HOPEFULLY, WE ARE AT LEAST IN THE BALLPARK NOW. WE DO FEEL THAT A NUMBER OF LOCATIONS IN THE EAST WILL CHALLENGE RECORD HIGHS ON MONDAY. THE FROPA NOW LOOKS TO BE LATE MONDAY NIGHT OR TUESDAY MORNING, FOLLOWED BY A SHOT OF SLIGHTLY COOLER, BUT DEFINITELY NOT COLD AIR FOR THE MID-WEEK PERIOD. IN THE MEANTIME, A QUIET NIGHT IS COMING UP WEATHER WISE.

Forecast Discussion:

04/06/2011

5DAY STARTS DAMP & COOL, BUT ENDS WITH 70S!

THIS IS A CLASSIC TIME OF THE YEAR WITH HUGE CONTRASTS IN THE WEATHER...ON THIS DATE ONE YEAR AGO, IT WAS UNSEASONABLY WARM WITH A HIGH OF 78. BACK IN 1982, WE HAD A LATE SEASON SNOWSTORM ON THIS DATE WITH 6-10" OF SNOW IN THE METRO AREA. FOLLOWING THAT STORM, STRONG WINDS CAUSED EXTENSIVE BLOWING AND DRIFTING SNOW AS TEMPS FAILED TO RISE ABOVE FREEZING...EVEN WITH AN EARLY APRIL SUN! WE WILL BE IN BETWEEN THOSE TWO EXTREMES OVER THE NEXT FEW DAYS, BUT WE DO HAVE A SHOT AT GETTING PRETTY WARM HERE BY NEXT MONDAY.

A COMBINATION OF FACTORS IS LEADING TO THE AREA OF RAIN THAT IS IN OUR BACKYARD NOW. THERE IS SOME WARM ADVECTION OCCURRING, THERE IS A JET STREAK PUSHING INTO THE NORTHEAST, RESULTING IN UPWARD MOTION IN THE RIGHT REAR QUADRANT OF THAT JET BACK INTO THE UPPER OHIO VALLEY AND LOWER GREAT LAKES REGION, AND FINALLY...A SURFACE FRONTAL BOUNDARY STRETCHES FROM THE MIDWEST INTO THE NORTHEAST. FOR TONIGHT, WE WILL JUST HAVE TO NOWCAST THE SITUATION BASED ON THE LATEST RADARS AND SURFACE OBS. IF THERE IS ENOUGH PRECIP THAT FALLS, IT IS NOT OUT OF THE QUESTION THAT TEMPS ALOFT AND NEAR THE GROUND ARE JUST CHILLY ENOUGH FOR SOME WET SNOW AT TIMES IN THE POCONOS AND SOUTHERN CATSKILLS...MAINLY ABOVE 2000 FEET. AS FOR RAINFALL TOTALS ACROSS THE AREA TONIGHT, WE CAN SEE AS LITTLE AS A TENTH OF AN INCH OR LESS, AND PERHAPS AS MUCH AS 1/3" TO 1/2".

BEHIND THIS FEATURE, MOISTURE WILL LINGER FOR AWHILE TOMORROW. THE SOUNDINGS ARE SHOWING SOME DRYING TOMORROW AFTERNOON, BUT IT WILL LIKELY BE IN THE MID TO LATE AFTERNOON. HOW HIGH TEMPS GO TOMORROW WILL DEPEND ON IF AND WHEN THE CLOUDS BREAK.

AFTER A BRIEF RESPITE, ANOTHER WAVE WILL COME EASTWARD IN THE FLOW ON FRIDAY. THERE SEEMS TO BE A BATTLE GOING ON BETWEEN THE AMERICAN MODELS (NAM AND GFS) AND THE GLOBAL MODELS (EURO, CANADIAN, AND UKMET) AS TO HOW FAR NORTH AND EAST THE RAIN SHIELD WITH THAT NEXT FEATURE WILL GET. OF COURSE, THE TIMING OF THAT WAVE AND ITS PRECIP IS ALSO UP FOR GRABS. FOR NOW, SOME SORT OF COMPROMISE IS PROBABLY IN ORDER, BUT I AM LEANING TOWARD THE GLOBAL MODELS. THE BOTTOM LINE IS THAT THE EARLIER ANY RAIN GETS HERE ON FRIDAY, AND THE MORE IT RAINS, THE COOLER IT WILL BE. OBVIOUSLY, TEMPS WILL BE HIGHER IF THE OPPOSITE THINGS HAPPEN.

OVER THE WEEKEND, WE WILL PROBABLY HAVE TO DEAL WITH A PERIOD OF ENHANCED CLOUDINESS AND PERHAPS A COUPLE OF SHOWERS AS THE WARM FRONTAL BOUNDARY STARTS WORKINGS ITS WAY NORTHEASTWARD. WE FACE A PRETTY DIFFICULT TEMP FORECAST HERE SATURDAY, SUNDAY, AND MONDAY. HOWEVER, WE ARE BECOMING INCREASINGLY CONFIDENT THAT BY MONDAY, WE WILL BE IN A TRUE "BLOW TORCH" OF A SOUTHWESTERLY FLOW. WE TOOK TEMPS UP ON SUNDAY, AND EVEN MORE SO ON MONDAY. WE STILL MAY NOT BE WARM ENOUGH! THE NEXT FROPA WILL OCCUR MONDAY NIGHT OR TUESDAY.

04/05/2011

TYPICAL SPRING PATTERN ON TAP

Good evening. A powerfeul cold front moved through the tri-state area late this morning / midday and in its wake we have been left with gusty west winds and temperatures falling into the 30s later tonight. Gusty west winds this evening will gradually diminish overnight, but a breeze will remain through the overnight to prevent significant radiational cooling.

Weak surface ridge will promote a clear and chilly start to the day tomorrow. However, clouds will be on the increase during the midday and afternoon hours associated with a fast moving shortwave nearing from the Great Lakes and developing warm advection. Showers associated with this feature will cross the lower Great Lakes tomorrow and may even evolve into a swath of steadier rain somewhere in the vicinity of Lake Erie into northern PA / southern NY heading into the afternoon with a jet max overhead and enhanced surface moisture convergence setting up in this area. Although the low-levels will be quite dry in our area tomorrow, given the fast flow in place there should at least be virga showing up on radar over the tri-state area later tomorrow afternoon and would not be surprised if one or two spots get a shower sometime after 3 or 4 p.m., especially west of the city. Otherwise, west-southwest flow in advance of this feature should push temperatures up to near average for early April.

Best chance for a couple of showers, perhaps even a period of steadier rain, comestomorrow night into Thursday morning as the best forcing and moisture convergence will be in place associated with the strung out shortwave. Exactly where this band of steadier precip sets up tomorrow afternoon and tomorrow night is still uncertain (may only be a 50-100 mile wide band), but where it does set up, there can be around 0.25 of an inch of rainfall. The best chance for this appears to be across northern and central PA, northern NJ, and the general NYC metro area.

Some of this rain may make it as far south as Philadelphia and central NJ tomorrow night. Trailing vorticity, low-level moisture and light easterly flow will promote a damp start to Thursday and a good deal of cloud cover will likely linger through the afternoon. Temperatures were brought down Thursday, but we may still be too optimistic and it may struggle to get much above 50 if clouds hang tough.

Should be dry Thursday night into early Friday, but a warm front combined with some shortwave energy will bring a returned chance for rain during the day Friday. Uncertainty remains over the weekend on how this boundary ultimately behaves, but it would appear that the warm front will stall out for a time somewhere across the mid-Atlantic Saturday as the main area of low pressure will still be very far to the west, over the nations mid-section with high pressure over Atlantic Canada. As a result, we are keeping Saturday fairly cloudy and not all that warm. Sunday looks a bit brighter. Saty tuned

04/04/2011

COLD FRONT COLLIDES WITH MORNING COMMUTE

Good evening! It has indeed been an interesting day across the Tri-State area as the sharp warm front tried to push north but never quite made it past central New Jersey! Yes, the high in Central Park was nice peaking at 63 degrees just past 5 p.m. which is 6 degrees above the normal for April 4th and the first time we have broken the 60 degree mark since our balmy 77 degree high back on March 18th. We had light surface winds from southeast to northeast and even north all day on the north side of the warm front along with a good deal of cloud cover. However, the front did make it through both Wrightstown and Belmar shown by a wind shift into the southwest and temperatures reaching 77 and 70 degrees respectively but the front didn't even make it to Newark where the high was 63. The temperature in the Philadelphia area made it well into the 70s to around 80 degrees! This evening the front has actually slipped back to the south of Belmar where winds have come back around to the east and it has dropped into the upper 50s and may actually sag south of Wrightstown during the next hour or two. In addition, a weak low pressure system has formed along the front to our south. This makes it highly unlikely that the front will come back north through the Tri-State area tonight.

Showers and thunderstorms are still sliding east northeast from central PA into extreme northeast PA and into the middle Hudson Valley due to warm advection helped by the lower level jet. We will have to wait until this flow of moisture ahead of the approaching strong cold front arrives from the west and that will be after daybreak. That's not to say that we can rule a spotty shower or thunderstorm out earlier than that but I think we will be mainly dry overnight.

Temperatures have slipped into the mid to upper 50s in the light northeasterly low level flow across most of The Tri-State area but then later tonight as the cold front approaches, temperatures will probably rise back into the 60s as the winds switch into the south. Even if that warm front manages to get through parts of the Tri-State area after midnight ahead of the front, it probably won't get any milder than the middle 60s overnight. The front itself should cross the region from west to east between 7 am and 10 am and could be accompanied by some downpours of heavier rain and thunderstorms. There may be some brief wind gusts over 30 or 35 mph but any severe weather seems unlikely due to the time of day the front is arriving.

Behind the front for tomorrow, strong cold advection with an increasing northwest wind should bring drying and cooling allowing showers and storms to push east of us and temperatures steady or even slowly falling during the day. We still have the upper trough to deal with so there will probably be just breaks of sunshine as some cloudiness hangs tough. A weak low pressure system pushing to our north Wednesday afternoon and Wednesday night could trigger a couple of showers then clouds break on Thursday with seasonable temperatures will follow before our next chance for rain comes with an approaching storm system at the end of the week.

04/01/2011

STORM WAS A DUD. AVERAGE APRIL WEEKEND ON THE WAY.

THIS STORM REALLY WAS AN UNDER-ACHIEVER FOR OUR REGION. IN FACT, YOU CAN PROBABLY CALL IT A "DUD"! THERE WERE SOME REPORTS OF AS MUCH AS 4-6" OF SNOW IN PARTS OF THE POCONOS, BUT THE LOWER ELEVATIONS DIDN'T GET MUCH AT ALL. THERE ALSO WASN'T MUCH IN THE WAY OF LIQUID PRECIP ACROSS OUR AREA. NOBODY REPORTED MORE THAN 0.50". WITH THE LATER DEEPENING OF THE STORM, WINDS ALSO WEREN'T A BIG DEAL HERE. THE LOW PRESSURE SYSTEM IS STRENGTHENING NOW, HOWEVER,AND IT IS SNOWING HARD IN PORTIONS OF MAINE AND NEW BRUNSWICK. WE STILL HAVE THE LEFTOVER EFFECTS OF THIS STORM THIS EVENING WITH A FEW SHOWERS AND A CHILLY WIND.

OVERALL, THE WEATHER ON THIS FIRST WEEKEND OF APRIL WON'T BE ALL THAT BAD. MOST, IF NOT ALL OF THE TIME WILL BE DRY. IT NOW APPEARS THAT THE CLIPPER SYSTEM WILL DIVE PRETTY FAR SOUTH AND WEST OF US, AND WE WILL NOT HAVE ANY DIRECT EFFECTS FROM THAT FEATURE. HOWEVER, THE HEIGHTS WILL BE LOW HERE TOMORROW, AND THE AIR ALOFT WILL BE QUITE CHILLY. SO, WE DO HAVE TO ALLOW FOR AN AFTERNOON INSTABILITY SHOWER IN A FEW SPOTS. HEIGHTS WILL BE RISING DURING THE SECOND HALF OF THE WEEKEND, LEADING TO DRY CONDITIONS WITH NO WORSE THAN PARTLY CLOUDY SKIES WITH SLIGHTLY HIGHER TEMPS THAN TOMORROW. THERE WILL BE A NOTICEABLE BREEZE BLOWING AT TIMES BOTH DAYS OF THE WEEKEND, DUE TO THE FACT THAT THERE WILL STILL BE SOMEWHAT OF A PRESSURE GRADIENT, AND IT WILL BE WELL MIXED TO AT LEAST 850 MB.

THE NEXT BIG CHALLENGE WE HAVE IS FIGURING OUT THE WARM FRONT SITUATION ON MONDAY. WHEREVER THAT FRONT GOES COME THROUGH, IT WILL REALLY BLOW TORCH. THAT CERTAINLY SEEMS LIKELY OUT WEST OF THE MOUNTAINS, AS WELL AS SOUTH OF MASON-DIXON LINE. THE FARTHER NORTH AND EAST YOU GO ON MONDAY, THE MORE OF A STRUGGLE IT WILL BE FOR THE WARMER AIR TO GET IN. BEFORE ANY SURGE IN TEMPS OCCURS, THOUGH, WE WILL HAVE TO DEAL WITH A PERIOD OF WARM ADVECTION RAIN OR SHOWERS...MAYBE EVEN SOME ELEVATED THUNDER, ESPECIALLY NEAR THE FRONTAL BOUNDARY.

MONDAY NIGHT WILL LIKELY BE A VERY BALMY NIGHT, AND TEMPS WILL HOLD STEADY OR RISE IN AREAS WHERE IT REMAINED COOL ON MONDAY. THE NAO (NORTH ATLANTIC OSCILLATION) IS CURRENTLY TRENDING TOWARD NEUTRAL, FROM A VERY NEGATIVE LEVEL. THE MODELS ARE FORECASTING THE NAO TO GO POSITIVE IN THE NEAR FUTURE. THAT WOULD ARGUE FOR A FASTER MOVEMENT OF SYSTEMS. INDEED, THE CURRENT RUN OF THE MODELS SUGGESTS THAT TREND. SO, WE DID HAVE TO MAKE SOME ADJUSTMENTS TO OUR FORECAST BY THE MIDDLE OF NEXT WEEK. THE COLD FRONT WILL SWEEP OFF THE EAST COAST ON TUESDAY, PRECEDED BY WARM WEATHER BUT FOLLOWED BY GUSTY WINDS AND A BRIEF SHOT OF CHILLIER AIR.