Thursday, February 17, 2011

Models Continue To Remain At Odds..Feb 20-22nd Winter Weather Possible

Today the 12 Z models continue to remain at odds in reference to the upcoming time period. The GFS last night at 00z was taking wave #1 pretty far to the north and suppressing wave #2. At 6 Z it brought wave #1 further to the south and brought wave #2 further north. Both waves brought a decent amount of frozen to the region from N & W of the big cities on part #1 and then part #2 delivered frozen to the big cities.

00z ECM last night brought the wave pretty far to the north and actually sheared out the 2nd wave…

So models have been pretty much flipping like a fish out of the water on dry land.

Today at 12 Z the GFS takes wave # 1 well to the north..

12zgfs850mbTSLPp06096

This brings warmer air into the region and would end up in a liquid event across the state of PA..

For part 2 the GFS is somewhat suppressed but off the coast and brings precipitation up to about east central PA…

12zgfs850mbTSLPp06120

12 Z GGEM @ 96 take the first wave similar to the GFS and also the 2nd wave similar to the GFS..

12_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_096

12_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_120

This brings us to the ECM & the NOGAPS…

12zeuro850mbTSLPNA096

12zeuro850mbTSLPNA120

The ECM at 96 hours is actually further to the south then what the GFS/GGEM is. Looking at the 6 hr plots..precipitation starts to move into the region around 90 hours out.. and moves the precipitation from the first wave out by 102 hrs but already on its heals is wave # 2 with the precipitation moving in between 108 –114 hrs..and then this area of precipitation moves out by 132 hrs.

Temperatures are as follows:

90 hours out they are 30-35 degrees to the N & NW of KPHL and from Central NJ on north ..south of that line it is 35-40.

96 hrs..essentially the same thing as 90 hrs with the exception of the 30-35 degrees is slightly further to the south..

102 hrs.. all of NJ is in the 35-40 with the exception of extreme NW NJ ..SE pa is also 35-40 and then from about ABE on north it is 30-35 degrees and west of there its also colder as well..

108 hrs out everyone is either at or below freezing except for the southern Half of Jersey..into DE

114 hrs out temperatures are now below freezing everywhere and in the teens in some locations (such as northern PA to about ABE 20s south of there ..from extreme SNJ into DE 30-35

120 hrs out.. temperatures are below freezing everywhere in the teens and 20s ..the exception is Southern DE where it is 30-35..

126 temperatures are below freezing everywhere again but southern DE..

132.. same thing with the temperatures as above..

850s never get above freezing from about east central PA and northwards…they do south of there but they also begin to drop off. For the second event 850s are cold enough basically the entire region..(referring Md/PA line North)

Now total QPF is around an .75-1.00 inches and more to the west in west central and western PA..

So the ECM is suggesting a all frozen event for east central PA from Sunday into Tuesday..and the second part would be all frozen even in locations like KPHL NYC etc.

The NOGAPS is very similar with its depiction of the first wave but it is slower with the second wave..Perhaps an indication that the second wave may be slower then what is being indicated..

12znogaps850mbTSLPp12096

12znogaps850mbTSLPp12108

12znogaps850mbTSLPp12120

12znogaps850mbTSLPp12132

12znogaps850mbTSLPp12144

This is something we will have to keep an eye on.

At this point and time, even though we are experiencing very mild conditions and most have given up on winter weather we are issuing a level 1 Alert for the area from Just north of KPHL for wave #1 into NW NJ and west of there and into SNE for wave # 2.

While many have felt the need to proclaim that winter is over..we here feel it is prudent to remind the readers that this period has the potential to deliver wintery weather. Again it is going to be dependent on where the Polar Boundary sets up.

Stay tuned to R.W.S for more updates and any watches or special weather statements if they be needed.

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