Models are beginning to come into agreement on this system. As of 00z yesterday the only model that remained to be south and east and OTS was the 00z NAM.
It should be noted however that as of the 6 Z NAM run ..it to has decided to come around to the party of the rest of guidance but pretty much like the GFS is still playing catch up.
People continue to not understand how the NOGAPS is actually used as a forecasting tool. They continue to say its a horrible model etc ..but this boils down to ignorance on their part.
A pro met went so far to say that HPC never references the NOGAPS and yet yesterdays morning HPC said the following:
EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
140 PM EST SUN JAN 23 2011
VALID 12Z WED JAN 26 2011 - 12Z SUN JAN 30 2011
GUIDANCE OFFERS A COMPLICATED SHORT RANGE MESS INTO MIDWEEK WITH
MUCH ABOVE NORMAL FORECAST SPREAD WITH POTENTIAL SRN STREAM STORM
DEVELOPMENT AND ASSOCIATED HEAVY PCPN POTENTIAL OUT FROM THE SERN
US AND UP/OFF THE EAST COAST INTO THU. UNCERTAINTY WITH UPSTREAM
KICKER ENERGY...CONVECTIVE FOCUS...AND NRN STREAM INTERACTION HAS
LEAD TO SIGNIFICANT TIMING AND SUPPRESSION ISSUES WITH THE STORM.
THE OO UTC ECMWF/UKMET/CANADIAN AND TO A LESSER EXTENT THE 00 UTC
GFS CONTINUE TO FAVOR A DEEPENING LOW TRACK MORE ON THE WESTWARD
PORTION OF THE ENTIRE SOLUTION ENVELOPE IN STARK CONTRAST TO THE
MORE SUPPRESSED 00 UTC NOGAPS AND 06 UTC GUIDANCE INCLUDING THE
NAM/DGEX AND ESPECIALLY 06 UTC GFS THAT WAS LESS PROGRESSIVE WITH
BOTH SRN STREAM KICKER ENERGY AND LEAD LOW DEVELOPMENT.
Now, as you can see by that..the NOGAPS was indeed mentioned and the NOGAPS was referenced to which means that HPC considers it part of the guidance that they use and view. Essentially like i said..some people including Pro Mets are ignorant of reality and we here at R.W.S like to keep things real!
So, lets look at the NOGAPS once again and see where it is and see if indeed the models have trended west of it.
Now lets look at the rest of the guidance. We are going to start with the GFS.
As you can see the GFS is in about the same location that the NOGAPS is in. This is a flag to the GFS..even though it has trended west and amplified more..this model continues to play catch up to the rest of the guidance.
Next up is the GGEM..
At 72 hours you can see that the GGEM is over approximately DE. Many think that this is east of its run at this point but the reality of it is that it is actually south at this time because it is slower.
At 78 hrs is where it actually came east…
However, it is still inland and basically going over the top of NYC. Almost looks to travel over Cape May and move NNE from there.
So you can see that the GGEM is west of the NOGAPS but this should not be surprising because this model has been consistently west at one point showing the extreme western track of the NOGAPS that i actually noted in earlier discussions was too far west…
UKMET at 72 hours is tucked in well to the coast and is also west of the NOGAPS. I do not have the in between image for 78 hours but at 84 hours it is also relatively in the same place as the Nogaps which means it will be trending further to the west in future runs. Remember UKMET also has a suppressive bias beyond 72 hours.
Next model up is the ECM..
You can see that the ECM is also tucked into the coast at 72 hours. At 78 hrs the 850 low is literally hugging the coast of NJ..By 84 hrs its literally about 50 miles from Cape Cod. ECM means are slightly inside the BM..
Here is the total QPF image
(removed accuweather request)
The above image is thru 96 hrs. Now for the breakdown of the 850s and the surface temps.
1.@ 60 hrs the 850s are below freezing from the N half of MD east into NJ ..the only part of NJ above freezing at 850 is SNJ…the lower portion.
@ 60 surface all areas are below freezing with the exception of SNJ ..lower portion again which is 35-40
2.@66 hrs 850s are below freezing from about western central MD and west.. to the east in MD 0 to +5 and that goes NE and divides NJ in half..southern is above and northern is below with NYC straddling the middle. SE pa also above ..but only 20 miles N & W of cities it is below freezing.
@66 surface..se PA all of NJ but extreme NW NJ and along the coast of SNE temps are 35-40. Extreme SC & SE NJ along the coast is 40-45 . 20-30 miles N & west of the big cities temps are at 30-35.
3. @ 72 hrs..850s are at about the ABE area as the dividing line between below freezing and above freezing. Essentially use I-78. All of MD with the exception of W Central Md is above freezing at 850..All of NJ as well with the exception of extrem NNJ and NW NJ..going along the coast of SNE the region remains below freezing.
@ 72 surface..surface crashes back so that south of KPHL NE into NJ drawing a line dividing the state in half on a SW to NE basis from the PA/NJ border (south of KPHL) ..is 35 to 40. KPHL and areas N & W are 30-35 and 20s further North into NY state area.
4. @ 78 All areas are below freezing with the 850s with the exception of extreme southern NJ and into East DE.
@ 78 surface virtually all areas at 30-35 or lower other then the areas above mentioned at 72 hrs.
5. @ 84 hrs.. all areas below freezing at 850 level but cape cod…
@ 84 surface all areas are at 30-35 or lower depending on location (basically same as 78 hrs) with the exception of extreme SNJ & Cape Cod.
6. 90 hrs 850s all areas are now below freezing and surface temps are 35-40 from SE PA into all of NJ but NW NJ..North and W of those locations are 30-35 or lower.
There you have the break down with the latest QPF above from the European Computer Model. Verbatim basically it looks like the Major Cities would go from a rain over to a heavy wet snow ..the exception to this would probably be South Central NJ along the coast into NJ and Delaware. This area at this present time looks to be mainly rain perhaps starting off as a wintery mix.
It must be noted that every track that you see tonight on guidance has already been shown on the NOGAPS long before any of the other guidance picked up on it. So for those that say the NOGAPS is not a good model..when it is more NW then the rest of the guidance..there is a reason that the rest of the guidance moves more NW with time. That reason is the NOGAPS is a progressive model with a SE bias and should not be that far NW to begin with so it points the errors out to the rest of the guidance.
So to sum things up..R.W.S is keeping the Level 3 alert for interior regions for the potential of a heavy wet snowfall.
If the QPF is anywhere near what the GGEM/ECM is suggesting these interior regions more east to less west would see anywhere from 15-17 inches in the east to 6-12 inches more to the west. These type of accumulations of heavy wet snow would be the type that would lay heavy on the trees and wires and could also cause power outages.
This storm has the potential to be a dangerous storm. The above is not a forecast but just laying down what the ECM is actually showing and suggesting.
Stay tuned for more information on this developing winter storm & look for future special weather statements as the specifics become more clear!
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