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August 2010

08/31/2010

HEAT & GETTING DOWN TO DETAILS OF EARL

WE ARE IN THE MIDST OF A VERY SIGNIFICANT LATE SEASON HEAT WAVE, AND THE HOT WEATHER WILL BE WITH US FOR AT LEAST TWO MORE DAYS. HOWEVER, THE HEAT WILL TAKE A BACK SEAT TO THE TROPICS. EARL IS A VERY FORMIDABLE CAT 4 HURRICANE, AND WILL LIKELY REMAIN A CAT 4 STORM FOR THE NEXT COUPLE OF DAYS AS IT TRACKS NORTHWESTWARD TOWARD THE EAST COAST OF THE U.S . EARL'S STRUCTURE HAS BEEN REORGANIZING SOMEWHAT TODAY, AND THAT HAS PREVENTED IT FROM INTENSIFYING. WE EXPECT THIS HURRICANE TO MORE OR LESS MAINTAIN ITS CURRENT INTENSITY THROUGH THURSDAY OR THURSDAY NIGHT, ALTHOUGH THERE WILL BE A FEW UP AND DOWN PULSES IN STRENGTH AS IT CROSSES AREAS OF SLIGHTLY DIFFERENT WATER TEMPS AND WIND SHEAR.

LOOKING AT THE TRACK OF EARL, AND THE WINDOW OF MOVEMENT, RIGHT NOW VS. YESTERDAY, WE HAVE MADE THE FOLLOWING ADJUSTMENTS: (1) WE HAVE SLOWED DOWN EARL'S FORWARD SPEED A LITTLE, ESPECIALLY ON THURSDAY AND FRIDAY. (2) WE HAVE ADJUSTED THE TRACK SLIGHTLY TO THE WEST FROM WHERE IT WAS YESTERDAY. OF COURSE, WE DO HAVE TO KEEP IN MIND THAT A VERY SIGNIFICANT UPPER LEVEL TROF WILL BE APPROACHING FROM THE WEST LATE THIS WEEK. THAT SYSTEM IS DESTINED TO BRING A REALLY NOTICEABLE COOL DOWN HERE THIS COMING WEEKEND. THE QUESTION IS...WILL THAT TROF BE THE MAIN PLAYER LATE IN THE WEEK, OR WILL IT BE EARL? IN OTHER WORDS, WILL EARL KEEP THE RIDGE PUMPED UP MORE AND FOR A LONGER DURATION TO ITS NORTH AHEAD OF IT ON THURSDAY INTO FRIDAY, THUS SLOWING DOWN THE APPROACH OF THE TROF FROM THE WEST? OR, WILL THE TROF BE THE KEY MOVER? IF THE LATTER IS THE CASE, THEN THE QUESTION IS...WILL THE TROF ACT TO BOOT EARL EASTWARD AND OUT TO SEA, OR WILL IT TRY TO DRAW THE STORM FARTHER WESTWARD AND INTO THE TROF? THE DEEPER THE TROF BECOMES AND THE MORE IT TILTS TOWARD NEUTRAL OR NEGATIVE, THE MORE LIKELY IT IS TO PULL EARL FARTHER WEST. HOWEVER, FOR THAT TO HAPPEN, THE TIMING HAS TO BE JUST RIGHT. WHAT WE MAY SEE OCCUR IS THAT EARL MOVES A TAD SLOWER THAN WE EXPECT THROUGH THURSDAY NIGHT OR EARLY FRIDAY, AND THE HURRICANE TRACKS EVEN A LITTLE FARTHER WESTWARD THAN WE CURRENTLY THINK. THEN, AS IT COMES NORTHWARD LATE FRIDAY AND ESPECIALLY FRIDAY NIGHT, THE TROF WILL HAVE PUSHED INTO THE NORTHEAST BY THEN. AS LONG AS THE UPPER FLOW ISN'T TOO SHARPLY SOUTHERLY AT THAT POINT, THEN EARL MAY TEND TO JOG A LITTLE BIT FARTHER TO THE EAST AGAIN, ENDING UP ON THE CURRENT PATH THAT WE NOW HAVE.

WITH THE SLIGHTLY SLOWER MOVEMENT OF EARL, AND ITS POTENTIAL IMPACTS, WE DO FEEL THAT FROM ABOUT THE NORTHERN 1/2 OF NJ AND THE NORTHERN 2/3 OF PA ON NORTHWARD, TEMPS ON THURSDAY COULD BE JUST AS HOT AS TOMORROW. IN SOME CASES, TEMPS ON THURSDAY MAY ACTUALLY BE A DEGREE OR TWO HOTTER. ON FRIDAY, WE DID DECIDE TO ADD IN A NARROW SLIVER OF "A CHANCE OF RAIN" TO INCLUDE MORE OF DE, EASTERN NJ...EAST OF PHL, THE NYC AREA, AND A LITTLE MORE OF INTERIOR NEW ENGLAND. THIS WILL PROBABLY BE THE TYPE OF SYSTEM THAT HAS A VERY SHARP WESTERN CUTOFF TO THE RAIN AND WIND. IN FACT, WE DO EXPECT A NARROW STRIP OF SUBSIDENCE BETWEEN EARL'S INFLUENCE AND THE MOISTURE FROM THE APPROACHING COLD FRONT. IN THAT SKINNY ZONE, PERHAPS INCLUDING PLACES SUCH AS HAGERSTOWN, MD, HARRISBURG, PA AND BINGHAMTON, NY, IT MAY BE NO WORSE THAN PARTLY SUNNY ON FRIDAY, AND STILL VERY WARM TO HOT. OBVIOUSLY, IN THE AREAS WHERE IT RAINS ON FRIDAY, TEMPS WILL BE HELD DOWN CONSIDERABLY, AND IT WILL ALSO BE COOLING DOWN FARTHER WEST WHERE IT SHOWERS WITH THE FRONT. THERE ARE SO MANY UNCERTAINTIES REMAINING AT THIS JUNCTURE THAT WE NEED AT LEAST ANOTHER DAY TO BE MORE SPECIFIC WITH THE DETAILS IN OUR FORECAST.

08/30/2010

HEAT WAVE TAKES A BACKSEAT TO HURRICANE TRACKING

THE BIG UPPER LEVEL RIDGE THAT WE TALKED ABOUT ALL OF LAST WEEK HAS INDEED BUILT INTO THE EASTERN PART OF THE COUNTRY. THIS RIDGE IS ABOUT AT ITS PEAK STRENGTH RIGHT NOW, AND WILL REMAIN QUITE POTENT FOR ANOTHER DAY OR SO. AFTER THAT, IT WILL SLOWLY BUT SURELY BREAK DOWN LATER THIS WEEK, BUT PERHAPS NOT AS FAST AS THE MODELS ARE SUGGESTING. THAT IS BECAUSE OF ACTION GOING ON THE TROPICS, WHICH WE WILL GET TO VERY SOON.

THE 500 MB HIGH WAS LOCATED OVER CENTRAL VIRGINIA THIS MORNING, WITH OBSERVED HEIGHTS OF 597 DM AT PITTSBURGH, DULLES, WALLOPS ISLAND, AND GREENSBORO, NC. AT THE SURFACE, WE FIND A HIGH CENTERED BACK OVER THE HIGHER ELEVATIONS OF WV AND SOUTHWESTERN PA, WHICH IS PRETTY MUCH AS EXPECTED. WITH THE MASSIVE SUBSIDENCE GOING ON LATELY AND THE TREMENDOUS AMOUNT OF WARMING THAT HAS TAKEN PLACE ALOFT, SURFACE TEMPS HAVE TRENDED UP DRAMATICALLY OVER THE PAST FEW DAYS. WE ARE NOW DEALING WITH THE LATE SEASON HEAT WAVE THAT WE ADVERTISED FOR QUITE SOME TIME. ALSO, AS WE SUSPECTED, THIS AIR MASS WOULD GRADUALLY TRANSITION FROM A CLEAN, PURE, AND VERY COMFORTABLE REGIME TO ONE THAT IS "DIRTIER", HAZIER, AND SOMEWHAT MORE HUMID. INDEED, DEW POINTS HAVE CREPT UP DURING THE PAST TWO DAYS VIA EVAPORATION AND EVAPOTRANSPIRATION, AND FURTHER MOVEMENT IN THAT DIRECTION WILL OCCUR DURING THE NEXT FEW DAYS. IT DOES SEEM THAT THE MOST HUMID AIR IS CIRCULATING AROUND THE PERIPHERY OF THE UPPER LEVEL HIGH, COMING UP THROUGH THE MISSISSIPPI VALLEY, THE UPPER MIDWEST, THE GREAT LAKES REGION, AND THEN INTO SOUTHERN ONTARIO.

THE BOTTOM LINE IS THAT THE WEATHER HERE OVER THE NEXT TWO DAYS WILL BE VERY SIMILAR TO TODAY WITH MOSTLY SUNNY SKIES AND HOT TEMPS DURING THE MIDDAY AND AFTERNOON. THIS HEAT IS NOT QUITE AS EXTREME AS WHAT WE DEALT WITH BACK IN JULY, BUT RECORDS WILL BE CHALLENGED IN SOME LOCATIONS BOTH TOMORROW AND WEDNESDAY.

MEANWHILE, EARL IS A MAJOR HURRICANE, AND WILL LIKELY STRENGTHEN FURTHER AS IT TRACKS NORTHWESTWARD TOMORROW AND WEDNESDAY. WHILE THE HEAT AND CONTINUED DRY WEATHER IS CERTAINLY A MAJOR WEATHER STORY HERE, THE BIG STORY OF THE ENTIRE WEEK WILL DEFINITELY BE EARL, AND ITS FUTURE PATH AND IMPACTS ON THE EAST COAST. THE WAY IT LOOKS LIKE, EARL WILL CERTAINLY BE A BIG WAVE AND RIP CURRENT PRODUCER FOR THE EAST COAST BEACHES THIS WEEK...FIRST ALONG THE SOUTHEAST COAST, AND THEN LATER IN THE WEEK UP INTO THE NORTHEAST. DEPENDING ON ITS EXACT TRACK, AND THE ORIENTATION OF THE STORM'S MOISTURE AT THE TIME, THE BEACHES FROM THE OUTER BANKS OF NC TO EASTERN NEW ENGLAND COULD ALSO FEEL THE OUTER EFFECTS OF GUSTY WINDS AS WELL AS SOME RAIN. HOWEVER, AT THIS EARLY STAGE OF THE GAME, WE DON'T WANT TO GET TOO SPECIFIC WITH OUR FORECAST, SINCE THERE IS LIKELY TO BE A HUGE GRADIENT BETWEEN WINDY, RAINY CONDITIONS, AND TOTALLY DRY WEATHER WITH PARTLY CLOUDY SKIES. WE DO EXPECT A FAIRLY NOTICEABLE HIGH CLOUD SHIELD FROM EARL TO SPREAD NORTHWARD ON THURSDAY AND THURSDAY NIGHT. IF THE ARRIVAL OF THOSE CLOUDS IS DELAYED A BIT, THEN THURSDAY WILL END UP BEING ANOTHER PRETTY HOT DAY.

FRIDAY'S WEATHER IS TOTALLY DEPENDENT ON WHERE EARL IS MOVING, AND WHAT THE STORM'S STRUCTURE IS ATTHAT TIME. WHILE ODDS FAVOR EARL MAKING A LANDFALL SOMEWHERE IN ATLANTIC CANADA, WE CAN'T RULE OUT A HIT ON "DOWN EAST MAINE". OBVIOUSLY, EARL WILL BE OUR MAIN FOCUS AS WE MOVE THROUGH THIS WORK WEEK.

08/26/2010

TRANQUIL TIMES...EXCEPT FOR THE TROPICS

AS WE HAD EXPECTED, TODAY ENDED UP BEING A DRY DAY HERE A DOWNSLOPING NORTHWESTERLY BREEZE AND LOWERING DEW POINTS. THE SHOWERS ASSOCIATED WITH THE TROF WERE CONFINED TO NORTHERN NY STATE, NORTHERN NEW ENGLAND, AND SOUTHERN QUEBEC. THERE WERE ALSO A FEW SCATTERED SHOWERS AND T-SHOWERS THAT POPPED UP THIS AFTERNOON TO OUR SOUTH FROM VA INTO THE CAROLINAS...ALONG THE FRONTAL BOUNDARY.

TODAY WILL END UP BEING DAY #1 OF A LONG STRETCH OF DRY DAYS HERE. IN FACT, THE EARLIEST THAT WE CAN SEE A DROP OF RAIN IN OUR PART OF THE COUNTRY IS SOMETIME LATE NEXT WEEK. WE ARE GOING INTO THE EASIEST PERIOD OF WEATHER THAT WE HAVE HAD IN A LONG TIME, WITH VERY FEW CHALLENGES IN THE FORECAST. HEIGHTS ARE IN THE PROCESS OF BOTTOMING OUT NOW AS THE UPPER LEVEL TROF SWINGS THROUGH. HEIGHTS WILL THEN RISE DRAMATICALLY OVER THE NEXT COUPLE OF DAYS, REACHING THEIR PEAK EARLY NEXT WEEK. THIS MASSIVE RIDGE WILL THEN BE VERY SLOW TO BREAK DOWN LATER NEXT WEEK. DESPITE THE REALLY HIGH HEIGHTS, THICKNESSES ARE NOT FORECASTED TO BE UNUSUALLY HIGH. THAT'S BECAUSE THE SURFACE PRESSURES WILL ALSO BE QUITE HIGH FOR AN EXTENDED PERIOD OF TIME, MAKING THE THICKNESS BETWEEN THE 500 AND 1000 MB SURFACES A TAD LOWER. 850 MB TEMPS ARE PROGGED TO GET PRETTY WARM HERE IN THE DAYS AHEAD...TOPPING OFF IN THE RANGE OF +19 TO +21 DEGREES C. THAT IS NOT EXTREME, BUT IT IS MORE THAN WARM ENOUGH TO GENERATE A LATE SEASON HEAT WAVE HERE. 

THIS COMING HEAT WAVE WILL NOT BE ASINTENSE AS THE SCORCHING AND RECORD BREAKING HOT WEATHER THAT WE HAD TO DEAL WITH BACK IN JULY. HOWEVER, IT WILL DEFINITELY BECOME NOTEWORTHY. GIVEN THE FACT THAT IT IS LATE SUMMER, AND IT WILL SOON BE SEPTEMBER, WE DO EXPECT A FASTER COOL DOWN IN THE EVENINGS, AND A SLOWER WARMUP IN THE MORNINGS. ALSO, DEW POINTS WILL BE REALLY SLUGGISH TO RISE, AND WE REALLY DON'T HAVE ANY REFERENCE TO HUMIDITY IN OUR CURRENT FORECAST.

EVENTUALLY, IT WILL BECOME MODERATELY HUMID, AND THE AIR MASS WILL CERTAINLY TURN MORE STAGNANT AND STALE OVER TIME. BEFORE WE GET TO THAT POINT, HOWEVER, THE NEXT COUPLE OF DAYS WILL ABSOLUTELY GORGEOUS, AND THE NIGHTTIMES WILL FEATURE CLEAR SKIES, LIGHT WINDS, AND BIG RANGES IN LOW TEMPS ACROSS THE AREA.

THERE ARE ONLY A FEW QUESTIONS THAT HAVE TO BE RESOLVED... (1) HOW EXTENSIVE WILL THE LATE NIGHT AND MORNING FOG BE EACH OF THE NEXT FEW MORNINGS? AT THIS POINT, WE FEEL THAT IT WILL BE MAINLY CONFINED TO THE TRADITIONAL RIVER VALLEYS OF THE INTERIOR NORTHEAST. (2) WILL THIS BE A CASE WHERE MOS NUMBERS END UP GETTING BEAT AS THE GROUND DRIES OUT AND IT GOES SUPER-ADIABATIC? MAYBE, BUT THAT WILL TAKE SOME TIME, GIVEN HOW WET IT HAS BEEN RECENTLY. THIS IS DEFINITELY A DIFFERENT SITUATION THAN WHAT WE ENCOUNTERED BACK IN EARLY JULY. (3) EXACTLY WHERE WILL THE SURFACE HIGH WANT TO SETTLE? IF IT ENDS UP BEING MORE INLAND OVER THE MOUNTAINS, THEN COOLING SEA BREEZES ARE A LITTLE LESS LIKELY TO OCCUR ALONG THE EAST COAST BEACHES....OR AT LEAST THE SEA BREEZES WILL BE WEAK AND MAINLY LATE IN THE DAY.

IN THE TROPICS, DANIELLE WILL NOT BE ANY CONCERN TO US AT ALL, BUT THERE ARE A LOT MORE UNCERTAINTIES WITH EARL. BOTH STORMS ARE LIKELY TO CHURN UP THE OCEAN SOMEWHAT IN THE DAYS AHEAD, CAUSING SOME HIGHER SWELLS AND ALSO RIP CURRENTS ALONG THE SHORE. STAY TUNED...

08/25/2010

A FEW MORE RAINDROPS THEN DAY AFTER DAY OF DRY WEATHER

WE ARE STILL FEELING THE RESIDUAL EFFECTS OF THE PESKY CLOSED LOW THAT HAS BEEN AFFECTING OUR WEATHER THE PAST COUPLE OF DAYS. FORTUNATELY, THIS SYSTEM IS FINALLY OPENING UP AND GETTING KICKED EASTWARD OUT TO SEA AS IT SENSES THE UPSTREAM SHORT WAVE NOW MOVING INTO THE NORTHERN GREAT LAKES REGION. WE'LL HAVE TO KEEP A CLOSE EYE ON THE RADARS FOR LEFTOVER SHOWERS HERE AND THERE THIS EVENING, BUT THE TREND FOR TONIGHT WILL BE FOR THE ATMOSPHERE TO SETTLE DOWN AND PARTIALLY DRY OUT.

MEANWHILE, THAT UPPER LEVEL FEATURE IN THE UPPER MIDWEST, AND ALSO THE SURFACE COOL FRONT, ARE HAVING A TOUGH TIME CAUSING MORE THAN A SWATH OF BROKEN CLOUD COVER AND ISOLATED SHOWERS. THAT WILL LIKELY CONTINUING TO BE THE CASE AS THE FRONTAL SYSTEM WORKS ITS WAY EASTWARD OVER THE NEXT 24 HOURS. THE CURRENT SYSTEM WILL TAKE A LOT OF THE MOISTURE WITH IT AS IT DEPARTS THE SCENE. PLUS, THERE WILL BE VERY LITTLE SURFACE CONVERGENCE WITH THE FRONT ITSELF. FOR THAT REASON, POPS ARE VERY LOW HERE TOMORROW, AND IT WILL PROBABLY JUST END UP BEING A DRY DAY. EVEN SO, IT DOESN'T HURT TO COVER FOR A BRIEF SHOWER IN ONE OR TWO SPOTS. WE FEEL THAT THE BEST CHANCE OF SHOWERS TOMORROW WILL BE RIGHT NEAR LAKES ERIE AND ONTARIO, WHERE 850 MB TEMPS WILL BE AS MUCH AS 16 TO 18 DEGREES C LOWER THAN THE LAKE SURFACE TEMPS. THAT WILL ACTUALLY LEAD TO LAKE-EFFECT INSTABILITY CLOUDS AND SHOWERS NEAR AND SOMEWHAT DOWNWIND OF THE LAKES. SCATTERED SHOWERS ARE ALSO MORE LIKELY TO OUR NORTH ACROSS THE NORTHERN HALF OF NY STATE AND NORTHERN NEW ENGLAND, WHERE THE HEIGHT FALLS AND PVA FROM THE SHORT WAVE ARE MORE PRONOUNCED. IN ANY CASE, WE DO EXPECT TOMORROW TO BE A BREEZY, WELL MIXED DAY WITH THE AIR MASS PROBABLY ABLE TO SQUEEZE OUT EVERY DEGREE OF WARMING.

AFTER TOMORROW, OUR WEATHER PATTERN WILL BE ABOUT AS SIMPLE AND STRAIGHTFORWARD AS IT GETS. IN FACT, WE WILL BE HEADING INTO THE EASIEST WEATHER PATTERN THAT WE HAVE SEEN IN QUITE SOME TIME, AS A HUGE UPPER LEVEL RIDGE BUILDS INTO THE NORTHEASTERN PART OF THE COUNTRY. THAT, IN TURN, WILL MORE OR LESS LOCK THE SURFACE HIGH IN PLACE, GIVING US DAY AFTER DAY OF BRIGHT SUNSHINE BY DAY, AND CLEAR SKIES AT NIGHT. AT FIRST, THIS WILL BE A VERY PLEASANT PATTERN. HOWEVER, OVER TIME, THE AIR MASS WILL WARM UP DRAMATICALLY, AND WE WILL EVENTUALLY BE DEALING WITH A LATE SEASON HEAT WAVE. THE DEW POINTS WILL BE SLOW TO COME UP IN A PATTERN LIKE THIS, BUT THE AIR MASS WILL GRADUALLY BECOME MORE STAGNANT ANDHUMID OVER TIME.

 IN THE TROPICS, HURRICANE DANIELLE WILL STRENGTHEN OVER THE NEXT COUPLE OF DAYS AS IT HEADS NORTHWESTWARD. TROPICAL STORM EARL HAS NOW JOINED DANIELLE  IN THE ATLANTIC.

08/24/2010

TROPICS AND OUR TEMPS WILL BE HEATING UP

HURRICANE DANIELLE WEAKENED SOMEWHAT LAST NIGHT AS IT SUCKED IN SOME DRIER AIR FROM THE NORTH. HOWEVER, IT IS ALREADY SHOWING SIGNS OF RE-INTENSIFYING, AND THAT PROCESS IS LIKELY TO CONTINUE IN THE NEAR FUTURE. IN FACT, WE EXPECT DANIELLE TO RAMP UP TO A CAT 3 HURRICANE BY LATE TOMORROW OR TOMORROW NIGHT! WHILE THIS STORM WILL NOT BE AN ISSUE FOR THE EAST COAST OF THE U.S., IT COULD EVENTUALLY AFFECT PORTIONS OF ATLANTIC CANADA.

MEANWHILE, ANOTHER WELL-DEVELOPED DISTURBANCE SOUTH OF THE CAPE VERDE ISLANDS HAS GOOD POTENTIAL, AND WILL PROBABLY BECOME "EARL" IN THE NOT SO DISTANT FUTURE. SPEAKING OF HURRICANES, TODAY IS THE 18TH ANNIVERSARY OF "ANDREW" SLAMMING ACROSS SOUTH FLORIDA. LESS THAN TWO DAYS LATER, THAT STORM MADE A SECOND LANDFALL ON THE LOUISIANA COAST. THE UPPER-AIR PATTERN TAKING SHAPE IN THE LONGER RANGE IS CERTAINLY GOING TO BE VERY FAVORABLE FOR TROPICAL SYSTEMS...FIRST IN THE FAR SOUTHEAST AND IN THE GULF OF MEXICO AS A HUGE RIDGE BUILDS IN THE NORTHEASTERN PART OF THE COUNTRY. DOWN THE ROAD, THE CENTER OF THE RIDGE WILL LIKELY SHIFT FARTHER EASTWARD, AS TROFINESS BECOMES ESTABLISHED OVER THE NATION'S MID-SECTION. THAT PATTERN, IF IT DOES INDEED UNFOLD, WOULD BE A CLASSIC, RIPE SETUP FOR THE EAST COAST...IF THE TROF DOESN'T KEEP SHIFTING EASTWARD.

ALL OF THAT STUFF IS LONG RANGE SPECULATION. ONE THING THAT DOES LOOK LIKE AN ALMOST SURE BET IS THAT AFTER THURSDAY, AN EXTENDED SPELL OF DRY WEATHER IS ON THE WAY HERE AS HEIGHTS RISE DRAMATICALLY. WITH A SURFACE HIGH PRESSURE SYSTEM SETTLING OVER US BY LATE FRIDAY OR FRIDAY NIGHT, AND THEN PRETTY MUCH PARKING ITSELF IN PLACE THROUGH THE WEEKEND INTO NEXT WEEK, THE RESULT WILL BE DAY AFTER DAY OF BRIGHT SUNSHINE, WITH CLEAR SKIES AT NIGHT. AT FIRST, THE AIR MASS WILL BE VERY COMFORTABLE AND REFRESHING WITH LOW DEW POINTS AND PLEASANT TEMPS. HOWEVER, THE AIR MASS WILL WARM UP QUITE A BIT BETWEEN FRIDAY AND SUNDAY, AND THEN IT WILL STAY VERY WARM WELL INTO NEXT WEEK. SINCE WE WILL NOT BE ADVECTING ANY STEAMY AIR INTO THE REGION FROM ANYWHERE, DEW POINTS WILL BE SLOW TO COME UP. THE INCREASE IN HUMIDITY WILL HAPPEN MOSTLY BY WAY OF EVAPORATION FROM WATER SOURCES, AND EVAPOTRANSPIRATION OFF OF VEGETATION. EVEN SO, WE COULD EVENTUALLY BE DEALING WITH A LATE SEASON HEAT WAVE BY EARLY NEXT WEEK.

IN THE SHORTER TERM, WE WILL CONTINUED DEALING WITH THE EFFECTS OF THE CLOSED UPPER LEVEL LOW. THE CENTER OF THIS SYSTEM WILL DRIFT SOUTHWARD FOR AWHILE, AND THEN FINALLY GET BOOTED OUT TO SEA BY LATE TOMORROW. AS THAT HAPPENS, AND ONE LAST PIECE OF ENERGY ROTATES THROUGH THE LOW, IT WILL PROBABLY DEEPEN THE SURFACE FEATURE SOMEWHAT THAT IS OFFSHORE. THAT SYSTEM WILL ENHANCE RAINFALL ACROSS NEW ENGLAND TOMORROW, ESPECIALLY OVER MAINE. THE FARTHER WEST YOU GO, THE LESS EFFECTS THAT LOW WILL HAVE. IN FACT, THE FARTHER SOUTH AND WEST YOU GO TOMORROW, THE MORE LIKELY IT IS FOR THE CLOUDS TO BREAK FOR SOME SUN, AND THERE WILL PROBABLY BE NOTHING MORE THAN A PASSING SHOWER. IN THE PLACES WHERE THE SUN COMES OUT TOMORROW, TEMPS WILL END UP BEING NOTICEABLY HIGHER THAN TODAY. HOWEVER, FARTHER NORTHEAST, ESPECIALLY ACROSS NEW ENGLAND, TOMORROW WILL BE ANOTHER COOL, RAW DAY. OUR BEST CHANCE FOR RAIN WILL BE THROUGH MIDDAY TOMORROW.

08/23/2010

TRACKING RAIN AND "DANIELLE"

THE TROPICS HAVE BEEN RELATIVELY QUIET SO FAR THIS SUMMER, WHICH IS REALLY NOT THAT UNUSUAL. CLIMATOLOGICALLY, THE PEAK OF HURRICANE SEASON IS THE LATTER PART OF AUGUST THROUGH THE MONTH OF SEPTEMBER, WITH THE ABSOLUTE PEAK OCCURRING ON SEPTEMBER 10TH. THERE HAVE BEEN MANY TIMES IN THE PAST WHEN NOTHING HAPPENS FOR WEEKS ON END, AND THEN WITHIN A WEEK TO 10 DAY PERIOD, WE ARE ALL OF A SUDDEN DEALING WITH THREE OR FOUR NAMED STORMS AT ONCE. WHETHER THAT HAPPENS THIS YEAR REMAINS TO BE SEEN.

WE ALREADY HAVE "DANIELLE", AND THERE IS ANOTHER BEEFY LOOKING WAVE THAT JUST CAME OFF OF AFRICA. "DANIELLE" HAS BECOME THE SECOND ATLANTIC HURRICANE THIS SEASON AND IT COULD EVENTUALLY BECOME A MAJOR (CAT 3) STORM WITHIN THE NEXT 24-48 HOURS IF IT UNDERGOES RAPID INTENSIFICATION. THE WATER TEMPS WHERE DANIELLE IS TRACKING ARE QUITE WARM, AND THE WEAK SHEAR THAT IS PRESENT NOW WILL DIMINISH TO ALMOST NIL DURING THE NEXT COUPLE OF DAYS. WHILE NOT THE ABSOLUTE CLASSIC CAPE VERDE TYPE OF STORM, DANIELLE HAS BEEN AND WILL CONTINUE TO BEHAVE IN A MANNER SIMILAR TO THE CLASSIC PATTERN. HOWEVER, UNLESS SOMETHING REALLY STRANGE HAPPENS LATER THIS WEEK, IT IS EXTREMELY LIKELY THAT DANIELLE STAY OUT OVER THE OCEAN AND NOT AFFECT U.S. MAINLAND.

CLOSER TO HOME, WE HAVE BEEN DEALING WITH A DEEP UPPER LEVEL TROF THAT HAS PINCHED OFF INTO A CLOSED LOW. THIS SYSTEM IS CENTERED CLOSE BY NOW, AND IS CURRENTLY DRIFTING SOUTHWARD. THIS PROCESS WILL CONTINUE INTO TOMORROW, BEFORE THE LOW WOBBLES MORE EASTWARD TOMORROW NIGHT AND WEDNESDAY, FINALLY PUSHING OFF OF THE MID-ATLANTIC COAST BY WEDNESDAY EVENING. AT THE SURFACE, A GENERAL AREA OF LOW PRESSURE ALONG AND JUST OFF THE EAST COAST WILL CONTINUE TO AFFECT US THE NEXT COUPLE OF DAYS WITH SOME CYCLONIC CURVATURE AND AN EASTERLY COMPONENT TO THE WIND FLOW...AT LEAST THROUGH TOMORROW NIGHT OR WEDNESDAY MORNING. WHAT THIS ALL BOILS DOWN TO IS MOSTLY CLOUDY SKIES AND SOME ADDITIONAL WET WEATHER WITH OCCASIONAL RAIN AND DRIZZLE.

AS IS ALWAYS THE CASE WITH CLOSED LOWS, THERE WILL BE PLACES WHERE THE PRECIP IS MORE ENHANCED THAN WE BARGAIN FOR, AND OTHER LOCATIONS WHERE POCKETS OF DRY AIR RESULT IN LITTLE OR NO RAIN FALLING FOR AWHILE. THOSE NUANCES WILL BE BEST DETECTED IN THE SHORT TERM BY STUDYING RADAR, WATER VAPOR, AND SATELLITE LOOPS. ONE THING THAT WE ARE CONFIDENT OF IS THAT TEMPS HERE THE NEXT COUPLE OF DAYS WILL BE CONSIDERABLY BELOW NORMAL FOR LATE AUGUST, AND NOTICEABLY COOLER THAN MUCH OF THE SUMMER HAS BEEN.

LOOKING AHEAD, BY THURSDAY, THIS CURRENT FEATURE WILL HAVE GOTTEN BOOTED OUT TO SEA, BUT ANOTHER SHORT WAVE TROF AND SURFACE COOL FRONT WILL BE ARRIVING FROM THE WEST. THAT SYSTEM MAY PRODUCE A SHOWER OR T-STORM HERE AT SOME POINT ON THURSDAY. HOWEVER, THERE WON'T BE A WHOLE LOT OF SURFACE CONVERGENCE WITH THE FRONT ON THURSDAY, AND SO PRECIP MAY TEND TO BE LIMITED. BEHIND THURSDAY'S SYSTEM, FRIDAY WILL BE A BREEZY, REFRESHING DAY AS A LARGE HIGH PRESSURE SYSTEM HEADS OUR WAY FROM THE MIDWEST. OVER THE WEEKEND, HEIGHTS ARE LIKELY TO CONTINUE BUILDING AS THE SURFACE HIGH WILL BE IN NO HURRY TO MOVE AWAY. THAT WILL PROBABLY LEAD TO AN EXTENDED SPELL OF DRY WEATHER WITH SUNSHINE EACH DAY AS WELL AS  A MAJOR WARMING TREND. IN FACT, BY EARLY NEXT WEEK, WE COULD BE DEALING WITH A LATE SEASON HEAT WAVE!

08/04/2010

HURDLE THE HEAT, THEN A FANTASTIC FINISH

IT CERTAINLY IS HUMID ACROSS THE REGION NOW, AND DEW POINTS WILL STAY FAIRLY HIGHTHROUGH TOMORROW. THAT IS NOTHING UNUSUAL FOR THIS TIME OF YEAR, AS DEW POINTS GENERALLY PEAK DURING THE SECOND HALF OF JULY AND THE FIRST TWO TO THREE WEEKS OF AUGUST. FORTUNATELY, WE ARE IN STORE FOR A NICE AIR MASS CHANGE LATER THIS WEEK, AND WE'LL HAVE A REALLY NICE START TO THE WEEKEND HERE ON SATURDAY.

 IN THE MEANTIME, WE DO HAVE A COUPLE OF OPPORTUNITIES FOR SHOWERS AND T-STORMS. ONE LEAD SHORT WAVE NOW OUT IN THE EASTERN OHIO VALLEY IS HEADING EASTWARD IN THE FLOW TONIGHT. ALTHOUGH IT IS QUIET ACROSS THE AREA NOW, WE WILL DEFINITELY HAVE TO KEEP A CLOSE EYE ON THE RADARS TONIGHT AS THAT FEATURE HEADS OUR WAY. IN ALL LIKELIHOOD, WE WILL JUST BE DEALING WITH SCATTERED ACTIVITY LATER TONIGHT.

AS THE MAIN COOL FRONT ARRIVES FROM THE NORTHWEST TOMORROW AND HEIGHTS BEGIN TO FALL INTO THIS STEAM AIR MASS, WE DO EXPECT ADDITIONAL T-STORMS TO FIRE UP. THE DISTRIBUTION, COVERAGE, AND INTENSITY OF THE T-STORMS TOMORROW IS STILL UP FOR DEBATE. HOWEVER, THERE IS A LEAST THE CHANCE OF A STRONG TO SEVERE STORM IN PARTS OF THE AREA. WE ARE IN A SLIGHT RISK ZONE FOR SEVERE T-STORMS TOMORROW, ALTHOUGH THE GREATEST POTENTIAL MAY BE FROM EXTREME SOUTHEASTERN PA AND THE SOUTHERN HALF OF NJ SOUTHWARD INTO PARTS OF DE, MD, AND VA. THE GREATEST THREAT IN T-STORMS TOMORROW SEEMS TO BE DAMAGING STRAIGHT LINE WINDS, SOME HAIL, AND BRIEF, DRENCHING DOWNPOURS. JUST HOW ACTIVE IT BECOMES TOMORROW AND HOW EARLY IN THE DAY T-STORMS FORM WILL HAVE A MAJOR BEARING ON HOW HOT IT GETS HERE. WE DO EXPECT SHOWERS AND T-STORMS TO PERSIST INTO TOMORROW NIGHT FOR AWHILE, BUT THINGS WILL QUIET DOWN BY THE LATE- NIGHT HOURS. THAT WILL SET THE STAGE FOR A NICER DAY WEATHER WISE ON FRIDAY WITH HUMIDITY LEVELS DROPPING DURING THE COURSE OF THE DAY, THANKS TO A NICE WEST TO NORTHWEST BREEZE. TEMPS ON FRIDAY WILL BE TRIMMED BACK SOMEWHAT FROM TOMORROW'S READINGS, BUT IT WILL STILL BE QUITE WARM.

AS THE AXIS OF THE UPPER LEVEL TROF SWINGS THROUGH ON FRIDAY AFTERNOON, HEIGHTS WILL REACH THEIR LOWEST POINT OF THIS FORECAST PERIOD. THAT UPPER TROF WILL ACTUALLY SUPPORT A WEAK SECONDARY COOL FRONT AT THE SURFACE. THAT SYSTEM MAY KICK OFF A BRIEF SHOWER OR T-SHOWER IN THE MOUNTAINS, AND ONE CAN'T BE RULED OUT FARTHER SOUTH AND EAST AS WELL.

HIGH PRESSURE SETTLING INTO THE NORTHEAST ON SATURDAY WILL GIVE US A GORGEOUS DAY WEATHER WISE. SUNDAY'S WEATHER WILL STILL BE DECENT, BUT IT IS LIKELY TO TURN STICKY AGAIN BY EARLY NEXT WEEK.