SPC MD 1795

MD 1795 CONCERNING HEAVY SNOW FOR CENTRAL NY

MD 1795 Image


Mesoscale Discussion 1795
NWS Storm Prediction Center Norman OK
0930 PM CST Mon Dec 11 2017

Areas affected...Central NY

Concerning...Heavy snow 

Valid 120330Z - 120930Z

SUMMARY...Snowfall rates will increase gradually through 06-09z,
with peak rates likely to exceed 1 inch per hour from about 07-12z.

DISCUSSION...In association with a midlevel shortwave trough
approaching the upper OH Valley, a deformation snow band has been
developing eastward over Lake Erie.  Low-midlevel warm
advection/ascent in advance of the trough, as well as weak
frontogenesis, will support additional eastward expansion of the
snow band across central NY through the early morning hours. 
Top-down saturation of the column is just beginning across western
into central NY, and snowfall rates will increase as column
saturation develops eastward and forcing for ascent increases
through the early morning hours.  Peak snowfall rates should
approach or exceed 1 inch per hour, and may persist for 3-6 hours at
locations within the expected corridor of the snow band.

..Thompson.. 12/12/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BTV...ALY...BGM...BUF...

LAT...LON   43217361 43007412 42747497 42497608 42457687 42517744
            42667771 43037760 43837544 44037419 43947361 43617347
            43217361 

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SPC MD 1787

MD 1787 CONCERNING HEAVY SNOW FOR FAR WEST-CENTRAL MS…CENTRAL AL…NORTHWEST GA

MD 1787 Image


Mesoscale Discussion 1787
NWS Storm Prediction Center Norman OK
0755 AM CST Fri Dec 08 2017

Areas affected...Far West-central MS...Central AL...Northwest GA

Concerning...Heavy snow 

Valid 081355Z - 081700Z

SUMMARY...Occasionally moderate to heavy snowfall (i.e. snowfall
rates around 1 inch per hour) are possible over the next several
hours across portions of central AL and northwest GA

DISCUSSION...Recent surface observations show that temperatures
across central AL and northwest GA have cooled enough to support
snow. Several sites are already reporting moderate snow with
isolated/brief instances of heavy snow (i.e. visibility less than
1/4SM) also being reported. Relatively heavier band of precipitation
is currently ongoing across southeast MS/southwest AL and its
northeasterly motion is expected to take it into central AL and
northwest GA over the next few hours. As a result, snowfall rates
may occasionally top 1 inch per hour in isolated locations.
Subfreezing surface wet-bulb temperatures are expected to remain
north of a line from MEI northeastward to RMG, keeping areas south
of this line predominately rain.

..Mosier.. 12/08/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...GSP...FFC...BMX...HUN...JAN...

LAT...LON   33358873 33918740 34848522 34838426 34348345 33448484
            32658684 32188908 33358873 

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from SPC Mesoscale Discussions http://bit.ly/1oC7Nya