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October 2009

10/19/2009

Tranquil Times Ahead

The unusually rainy and chilly weather that arrived last Thursday and lasted through most of the weekend has finally ended as the deep and chilly upper level trough over the finally pushed eastward into the western Atlantic today. The very active jet stream that led to a very unsettled weather pattern over much of the lower 48 has finally lifted north into the Great Lakes with a building upper level ridge in the central and eastern US and a strengthening surface high pressure system currently centered over the easternGulf States but sprawling all the way from the Gulf Coast into the northeastern US. The result was a much more pleasant October day today with a good deal of sunshine and temperatures only 7 degrees below normal as compared to the 10-20 degrees below normal we shivered through the past four days not to mention the relentless overcast and damp conditions.

The weather will get even better over the next few days as the jet stream stays well to our north and the surface sets up shop over the Eastern States. Tonight will be another chilly one with clear skies and light winds working on the very dry air mass leading to ideal radiational cooling conditions which should send readings down to the low to mid 40s in the city late but well down in the 30s bringing areas of frost for the second night in a row in the outlying suburbs. Our normal low is 48 and we should certainly end up several degrees under that yet not anywhere near therecord of 31 set back in 1974.

Tuesday should be absolutely gorgeous and warmer than today as the center of the surface high pushesinto the Carolinas allowing our winds to swing around into the west to southwest. Readings should actually get back above the normal (62) topping out in the middle 60s during the afternoon with a good deal of sunshine.....nice! Tomorrow night will be quiet again but temperatures should not be quite as cold probably bottoming out in the upper 40s in town to the frostless upper 30s and lower 40s outside of the boroughs.

Even more improvement Wednesday with the nearly stationary high centered over the Carolinas beingmoderated by days of sunshine and our winds staying out of the southwest. We should get above normal as a matter of fact on Wednesday afternoon with some locations taking a shot at 70 degrees! Thursday follows as the nicest of the next few as we get as much as we can out of the eastern US surface high. Most of us will do quite well with southwest winds and highs into the lower 70s!

We will have to watch for changes by the end of the week and into the weekend however. A storm system which is currently bringingsome rain to California and the intermountain west will push into the plains by Wednesday and into the Great Lakes by Thursday. It willactually be a double barrel low by then with one center in the Lower Great Lakes and the other in the mid-Mississippi Valley. The northernlow will push a cold front across the northeastern US Thursday night and stall it out over Virginia with a surface high pushing into the St.Lawrence valley behind it. Next the Mississippi valley storm which will become the primary low will push the old cold front back north from Virginia. That northward moving front with the surface high to our north over the St. Lawrence valley will set up a good overrunning situation with a cool easterly flow at the surface across our area and the rain developing across the area to the north of the warm front. The timing is challenging to say the least as to when the rain will actually start to fall in our area......maybe late Friday or Friday night but in any event Friday will be a less desirable day with cool east winds and plenty of clouds leaving high temperatures below normal once again. The storm system will intensify and the models are indicating a secondary low forming over the Delmarva Saturday afternoon then moving northeast along the coast. This should mean a pretty good soaking for the first half of the weekend indeed! Wet snow for the interior is not much of a concern this time as compared to the last storm as the system will be much more progressive and not haveas much opportunity to pull cold air into it's northern flanks before it heads northeast away from the area Sunday. Improving weather with increasing sunshine is in store for the last half of the weekend and into early next week but temperatures will be at or slightly below normal once again.

10/15/2009

Coldest October Storm since 1977!!!

SNOW IS HAS BEEN FALLING IN THE POCONOS, SOUTHERN CATSKILLS,  NORTHWESTERN NJ, AND THE HUDSON VALLEY. ADDITIONAL SNOW WILL FALL TONIGHT INTO TOMORROW. HOWEVER, AS THE PRECIP INTENSITY LIGHTENS UP SOMEWHAT BEHIND THE FIRST STORM, WE WILL LIKELY SEE MORE AREAS MIXING WITH RAIN, OR PERHAPS EVEN CHANGING BACK OVER TO LIGHT RAIN OR DRIZZLE. ALSO, BECAUSE OF THE RELATIVELY WARM GROUND, THE AREAS THAT DID GET SNOW WILL PROBABLY LOSE SOME SNOW COVER DUE TO MELTING FROM BELOW.

OVER THE WEEKEND, WE'VE GOT ANOTHER VERY INTERESTING SITUATION AS TO WHERE IT WILL SNOW, HOW HARD IT WILL SNOW, AND HOW MUCH WILL ACCUMULATE. THERE IS GREATER POTENTIAL FOR HEAVY SNOW AMOUNTS TO SHOW UP ON SATURDAY AND SATURDAY NIGHT, AS THE UPPER LEVEL TROF CONTINUES TO SHARPEN UP AND WEEVENTUALLY GET A CLOSED LOW TO FORM. HOWEVER, AT THE SAME TIME, THERE IS SOME WARMING FORECAST TO OCCUR ALOFT...AT 5000 FEET. SO, IT REMAINS TO BE SEEN IF THE UPWARD MOTION FROM THE CLOSED LOW WILL BE ABLE TO COUNTERACT ANY UPTICK IN 850 MB TEMPS. AT THIS STAGE, I FEEL THAT THE BEST SNOW ON SATURDAY WILL BE FALLING SOMEWHERE BETWEEN THE POCONOS AND THE MOUNTAINS OF CENTRAL PA, PROBABLY AT ELEVATIONS ABOVE 1500 FEET.

IF THERE IS INDEED SLIGHT WARMING DURING THE WEEKEND, THEN THE SNOW ZONE WILL PROBABLY PUSH A LITTLE FARTHER NORTH AND WEST. AS WE SAID YESTERDAY, THIS STRETCH OF WEATHER THAT WE ARE FACING FROM NOW THROUGH THE UPCOMING WEEKEND IS ABOUT IS NASTY, UGLY, AND COLD AS IT EVER GETS DURING THE MIDDLE OF OCTOBER.

IT STILL APPEARS THAT OUR FIRST NOR'EASTER WILL PUSH OFFSHORE LATER TONIGHT, AND THEN HEAD FARTHER OUT TO SEA DURING THE DAY TOMORROW. SO, AFTER A DECENT SOAKING TONIGHT, TOMORROW WILL JUST END UP BEING DAMP AND DISMAL WITH SOME LIGHT RAIN AND DRIZZLE FROM TIME TO TIME. THAT WILL ALSO BE THE CASE THROUGH MOST OF TOMORROW NIGHT.

THERE ARE STILL DIFFERENCES OF OPINION AMONG THE MODELS AS TO HOW THE WEEKEND SCENARIO WILL PAN OUT. THERE IS DECENT AGREEMENT ON THE EVOLUTION OF THE UPPER AIR PATTERN. THE SURFACE, HOWEVER, IS TRICKER TO FIGURE OUT. WILL WE GET A TOTALLY SEPARATE, WELL-DEFINED LOW PRESSURE SYSTEM TO DEVELOP ALONG OR JUST OFF OF THE MID-ATLANTIC COAST. OR, WILL THAT SECOND WAVE END UP WAY OUT IN THE OCEAN, WITH AN EXTENSION OF CYCLONIC FLOW BACK TOWARD THE COAST? FOR THE ACTUAL WEATHER, AFFECTING PEOPLE'S LIVES, THE MAP FEATURES MAY NOT MATTER A WHOLE LOT. WHAT MAY BE A BIGGER DETERMINING FACTOR IN WHERE THE STEADIEST AND HEAVIEST PRECIPFALLS THIS WEEKEND IS THE ORIENTATION OF THE UPPER LEVEL TROF, AND EVENTUALLY THE CLOSED LOW. THE BOTTOM LINE IS THAT WE DO HAVE TO INCLUDE ADDITIONAL RAIN AND DRIZZLE IN THE FORECAST FOR BOTH SATURDAY AND SUNDAY.

WE WILL LOOK AT THE SITUATION MORE CAREFULLY AT 11PM FOR DETAILS ON AMOUNTS AND TIMING. WITH THE SLOWMOVEMENT OF THIS MESS, WE HAVE TO BE CAREFUL NOT TO IMPROVE THE WEATHER TOO QUICKLY ON MONDAY. HOWEVER,IT SHOULD BE MUCH, MUCH NICER BY NEXT TUESDAY. ONE LAST NOTE...THERE IS NO CHANGE IN THINKING ABOUT THE COASTAL FLOODING AND BEACH EROSION SITUATION FROM YESTERDAY. THAT WILL BE AN ISSUE TO DEAL WITH INTO TOMORROW. THEN, AFTER A BRIEF, SLIGHT RESPITE, THINGS MAY GET WORSE AGAIN OVER THE WEEKEND, AS THE SECOND LOW FORMS.

10/08/2009

Two rounds of rain Friday

High pressure moves offshore tonight and clouds in the Ohio valley will move in this evening. Rain across the Ohio valley is being caused by a warm front and it will streak east tonight and reach ourarea after midnight. The warm front will extend east into southeast PA tomorrow morning and then it it will lift to our north in the afternoon. There can still be some rain tomorrow morning that will taper toshowers in the afternoon as the front lifts north and it will be cloudy and mild. Rainfall amounts latetonight and tomorrow will generally be on the light side, perhaps 0.05-0.20 inches.

Low pressure will pass by to the north tomorrow night and push a cool front into the city so look for clouds and showers tomorrow night that will end early Saturday morning. There may be a 0.25 inches of rain tomorrow nightinto early Saturday morning. Overall the heaviest rain will stay to our north later tonight into early Saturday morning with some locations up around Poughkeepsie getting 0.50 to as much as 1.00 inches.

Drier air will move in behind the front on Saturday and clouds will break for peeks of afternoon sun and seasonal temps. I expect more sun north of New York City.

High pressure passing by to our north will provide mainly clear skies Saturday night then it will shiftoffshore on Sunday as a cold front moves across Pennsylvania causing sunshine and patchy clouds.There may be a shower late Sunday or Sunday night.

Yet another cold front moves in Monday night and Tuesday with more clouds and the coldest air of the season.

10/07/2009

GUSTS GRADUALLY DIMINISH

The big story today has been the strong westerly winds, gusting on average between 40-50 mph. Winds have been fairly well aligned from the surface on up, this along with some sunshine mixing up the atmosphere has allowed some of those stronger winds to mix down to the surface this afternoon. Winds can still gust near 40 mph through this evening with tight pressure gradient remaining in place. Weak surface ridging builds over the mid-Atlantic tonight. This along with the loss of daytime heating will allow for a gradual decrease in the winds, but it will remain brisk through the overnight -- still gusting through the 20s.

A shortwave progged to move over the area late tonight should come through dry with drier air mass and an increasingly anticyclonic flow taking over. Otherwise, skies will turn out mainly clear overnight. The wind will help to keep temperatures from dropping off too much overnight.

High pressure, both at the surface and aloft, will promote a nicer day tomorrow with a good deal of sunshine and seasonable temperatures. It will still be breezy at times tomorrow with northwest winds gusting around 20-25 mph. Meanwhile, a surface low will develop over the southern Plains Thursday as a broad upper-level trough becomes better established across the nations mid-section and the upper-level low, currently shown up nicely on the water vapor over southern California, opens up and heads east across the Four Corner states. Some high level clouds may sneak in from the west later in the afternoon embedded in the westerly flow aloft.

Tomorrow night high pressure shifts off the coast as low pressure lifts northeast into the Ohio Valley with a cool front trailing southwest into central Texas. Warm advection cloud cover will increase across our area as the night progresses. It will take a while for the low-levels to moistenup, so most of tomorrow night should remain dry, although a few sprinkles or spotty light raincannot be ruled out toward daybreak across the western parts of the viewing area. A strong upper-level ridge centered over the southwestern Atlantic will tend to slow the forward movement of the approaching cold front Friday. Most computer models are in agreement with taking the center of low pressure northeastward to the lower Great Lakes region by the end of the day. This would give us the chance of getting into the warm sector Friday. There will probably be more in the way of clouds around Friday with the warm front lifting north -- perhaps a shower. If the warm front punches through our area faster, then temperatures will be able to get several degrees higher than what we are currently depicting. The best chance for a period of rain, even a thunderstorm, comes later Friday night as the cold front moves into the area. However, by this time a lot of the good upper-level support will be getting strung out to the north over eastern Canada, so the precipitation may end up being more showery in nature.

The frontal boundary should get far enough to our south and east Saturday to allow drier air tofilter in. However, more cloud cover and rain may be lurking just to our south as a broad southwest flow aloft will remain in place. As the front becomes increasingly parallel to the flow aloft, its forward progression will slow, so there could still be some rain as far north as southern

New Jersey and the Delmarva this day. Something to keep a close eye on over the next couple of

days. If the front is slower, then a more pessimistic start to Saturday will need to be in order forus. Otherwise, most of the weekend should turn out dry and cooler with high pressure nosing into the Northeast. A storm system moving into the Northeast early next week may be accompanied by some wet weather Monday followed by more significant cooling Tuesday and Wednesday.

 

10/06/2009

Wet then WINDY

After a crisp morning, plenty of sunshine today allowed temperatures to warm up nicely this afternoon. In addition, lighter winds allowed for a more comfortable day. The nice weather can be contributed to a 1017 mb high centered over the northern Delmarva.

Meanwhile, a 1000 mb low centered over southern Wisconsin has a cool front trailing southward through the Mississippi Valley back into central Texas. An associated warm front is lifting northward through the Ohio Valley. Clouds out ahead of this storm system are already increasing across the northern mid-Atlantic this afternoon. High pressure shifts offshore tonight while low pressure heads northeast across the Great Lakes states. Clouds will continue to increase and thicken across theregion tonight in advance of the approaching cold front. However, any rain will likely hold off until just after midnight tonight when the best moisture and upward motion will be moving into the area out ahead of the front.

We are only expecting a 5-7 hour window for precipitation as rain will shut off with the passage of the front between 7 am and 9 am tomorrow morning. When things are all said and done, most locations will pick up a general 0.25 to 0.50 of an inch of rain, locally 0.75 of an inch. The atmosphere is also quite unstable around sunrise, so I would not be totally surprised if there was a rumble of thunder. 700 mb moisture dries out quickly tomorrow morning and clearing skies should take place as early as mid-morning.

The combination of a tight pressure gradient between the departing storm and high pressure building over the Ohio Valley, decent downward transfer of stronger winds aloft and sunshine mixing up the atmosphere willmake for a very windy day. Some wind gusts tomorrow can be in excess of 40 mph, especially in the afternoon. You might see some home runs to right field tomorrow evening at Yankee Stadium.

High pressure building in tomorrow night will promote clear to partly cloudy skies. Winds will gradually diminish, but they will still be brisk out of the northwest. Ridging, both at the surface and aloft, should allow for a nice Fall day Thursday with seasonable temperatures under sunshine for the most part -- perhaps some high clouds later in the afternoon.

Forecast challenges remain Friday into Friday night. A large, broad trough will be in place acrossthe central part of the nation toward the end of the week. A storm system developing over the southern Plains Thursday will lift northeastward into the Great Lakes region by Friday. We will continue to allow for some more clouds along with a chance for a shower with the associatedwarm front lifting northward through the area. If the warm front makes faster progression northward, then Friday afternoon may end up warmer than what we are currently depicting. With the broad trough to our west and ridging pumping up in advance of it over the western Atlantic, it will likely take until later Friday night or Saturday morning for the actual cool front to move through the area which may be accompanied by a couple of showers.

With any luck, high pressure builds in to allow for the majority of the weekend to be dry. Although temperatures should gradually cool as the weekend progresses, it appears the core of the coldest air will set up over the northern Plains and upper Midwest.

10/05/2009

Outstanding October Weather

The pressure difference between a large low pressure system sprawled across central Quebec and a ridge of high pressure stretching from the southern Great Lakes into the western Atlantic generated a cool west to northwest flow across the region today bringing sunshine for the most part but also temperatures which were a few degrees below normal for October 5th.

The upper levels feature a strong jet stream flow diving south into the PacificNorthwest then curving around the southern edge of an upper level trough located over the Rockies then northeast into the central Mississippi Valley then east through the mid Atlantic States. The weak ridge of high pressure will driftright across the northeastern United States over the next 24 hours bring a mainly clear and rather chilly October night tonight and another mostly sunny day to follow tomorrow. Temperatures tomorrow should recover a few degrees toat or just above normal as the initially cool high is moderated by the early October sunshine.

The fast jet stream will carry a surface low which is presently over the central high plains eastward during the next couple of days. This system will move northeastward into the upper Mississippi Valley Tuesday spreading a southerly flow eastwardahead of it and bringing moisture with it. The cloudiness in advance of the approaching system will reach Western NY, Western PA and West Virginia Tuesday afternoon then spread across and east of the Appalachians to the east coast Tuesday night.

Overrunning rains north of a warm front pushing across the Ohio Valley into the Mid Atlantic States will spread into Western NY, western PA and West Virginia by Tuesday night and onto areas east of the mountains and to the east coast later tomorrow night and into early Wednesday. The storm center itself will intensify as it pushes across the Great Lakes tomorrow night and into the northeast on Wednesday. The associated cold front will trail the storm crossing western PA and West Virginia tomorrow night then quickly off the east coast Wednesday. Potential rainfall amounts will range from up to and inch over northern New York State and northern New England to right around a quarter inch across PA into New Jersey and the NYC area and perhaps a little less from Philadelphia down to Baltimore and the Delmarva.

After the passage of the cold front Tuesday night there will still be some instability showers over western PA, western NY and back into the Great Lakes Wednesday thanks to the cold upper level trough pushing out of the Great Lakes but some breaks of sunshine as well along with a gusty and cooler northwest wind. Rain east of the Appalachians will end before noon on Wednesday as the cold front pushes east of the coastline with cooler and stronger northwest winds behind it as skies clear. The westerlyflow with the next high pressure system entering the northeast later Wednesday and Thursday is not as cool and as a result Thursday should be quite nice with sunshine, less wind and temperatures slightly above seasonal averages.

The next system will ride the jet stream into the northeast at the end of the week probably bringing more rain to the western parts of PA and NY and West Virginia then east of the mountains and onto the east coast by Friday night. Windy and cooler weather will follow during the upcoming weekend with drying conditions once again .

All the models are advertising a strong cold front to move across the area Monday accompanied by a few showers and followed by the coldest air mass of the season so far during next week. High temperatures next Tuesday and Wednesday may not get out of the 40s and some snow shower activity is not out of the question around the GreatLakes! Even east of the mountains it will be quite cool with highs no better than the middle 50s despite sunshine!