Analyzed 00Z Mon Jan 23, 2017
Valid 06Z Mon Jan 23, 2017
Valid 12Z Mon Jan 23, 2017
Valid 18Z Mon Jan 23, 2017
Valid 00Z Tue Jan 24, 2017
Valid 12Z Tue Jan 24, 2017
Valid 00Z Wed Jan 25, 2017
Valid 12Z Thu Jan 26, 2017
Valid 12Z Fri Jan 27, 2017
Valid 12Z Sat Jan 28, 2017
Valid 12Z Sun Jan 29, 2017
Valid 12Z Mon Jan 30, 2017
+ Short Range Forecast Discussion (Day ½-2½)
+ Medium Range Forecast Discussion (Day 3-7)
Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
333 PM EST Sun Jan 22 2017
Valid 00Z Mon Jan 23 2017 - 00Z Wed Jan 25 2017
...There is a slight risk of severe thunderstorms over the
Southeast into parts of the Southern Mid-Atlantic with an embedded
region of moderate and high risk...
...Heavy rain possible along the Southern California Coast...
...Heavy snow for the Sierras...
...Heavy rain over parts of Southern New England...
Low pressure over the Southern Appalachians will move
northeastward to off the Mid-Atlantic Coast by Tuesday. Showers
and thunderstorms will develop over parts of the Southeast through
Monday morning, some of the thunderstorms will be severe. Rain
will also develop over parts of the Lower Mississippi Valley to
Southeast and parts of the Great Lakes/Ohio Valley along with
parts of the Mid-Atlantic that will end over the Lower Mississippi
Valley by Monday and over the Southeast overnight Monday. The
rain will also end over most of the Ohio Valley by Tuesday
morning. Snow will develop over parts of Maine on Sunday evening
that will expand into parts of the Lower Great Lakes and Central
Appalachians that will become a wintry mix of snow, sleet, and or
rain/freezing rain overnight Monday into Tuesday.
Meanwhile, a deep upper-level low just off the Northwest Coast
will move eastward to the Central High Plains by Tuesday.
Moisture flowing into Southern/Central California will slowly
weaken overnight Sunday. The storm will produce coastal rain and
higher elevation snow over the Pacific Northwest and snow over the
Northern Rockies that will wane on Monday. Rain and higher
elevation snow will also develop over California and snow over the
Western Great Basin that will start to wane by Tuesday morning.
Snow and lower elevation rain will develop over parts of the Great
Basin, Southwest that will move into parts of the Central/Southern
Rockies by Monday morning. In addition, snow and rain will
develop over parts of the Northern/Central Plains by Monday
evening continuing through Tuesday.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php
+ Additional Links
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1035 AM EST SUN JAN 22 2017
VALID 12Z WED JAN 25 2017 - 12Z SUN JAN 29 2017
...GENERAL FLOW PATTERN/MODEL EVALUATION...
IN THE WAKE OF A COASTAL STORM LIFTING AWAY FROM MAINE AND A
SURFACE CYCLONE TRACKING THROUGH THE GREAT LAKES ON
WEDNESDAY...THE PATTERN WILL BECOME FAIRLY QUIET OVER THE LOWER 48
DURING THE LATER HALF OF THE WEEK AND INTO NEXT WEEKEND. A BROAD
TROUGH CARVING OUT OVER THE EASTERN HALF OF THE NATION WILL HELP
PLUNGE A FRONTAL BOUNDARY WELL SOUTH INTO THE GULF OF
MEXICO...WHILE UPPER RIDGING AND SURFACE HIGH PRESSURE ARE
EXPECTED TO BUILD IN AND HOLD STRONG OVER THE WESTERN U.S..
THERE REMAINS SOME UNCERTAINTY WITH THE EXACT TIMING OF THE
SURFACE LOW CROSSING THE GREAT LAKES ON WEDNESDAY. THE WPC
FORECAST STAYED FAIRLY CLOSE TO THE 00Z ECMWF/UKMET/ECMWF ENSEMBLE
MEAN...WHICH HAVE BEEN CONSISTENTLY IN THE MIDDLE OF SLOWER CMC
SOLUTIONS AND FASTER GFS SOLUTIONS WITH THIS FEATURE...AND THE
ECMWF/UKMET/ECMWF ENSEMBLE MEAN ALSO MATCH WELL WITH THE PREVIOUS
WPC FORECAST. LATER IN THE FORECAST PERIOD...A BLEND OF THE 00Z
GFS/GEFS MEAN AND ECMWF/ECWMF ENSEMBLE MEAN APPEARED TO BEST
ACCOUNT FOR THE GOOD AGREEMENT AMONG DETERMINISTIC GUIDANCE WITH
THE LONGWAVE PATTERN...EVEN OUT THROUGH DAY 7/NEXT SUNDAY...BUT
THE BLEND ALSO SMOOTHED OUT SOME OF THE TIMING/AMPLIFIED
DIFFERENCES THAT DEVELOP WITH IMPULSES OF SHORTWAVE ENERGY DIGGING
INTO THE NORTH CENTRAL U.S. LATER THIS WEEK AND A POSSIBLE PACIFIC
SYSTEM REACHING BRITISH COLUMBIA NEXT WEEKEND.
SNOW IS EXPECTED WITH BOTH A COASTAL STORM EXITING MAINE AND
SURFACE CYCLONE TRACKING ACROSS THE GREAT LAKES ON WEDNESDAY...BUT
THEN PRECIPITATION SHOULD BECOME RATHER SPARSE ACROSS THE CONUS
TOWARDS THE LATER HALF OF THE WEEK AND THROUGH NEXT WEEKEND. AN
EXCEPTION TO THIS WILL BE ACROSS THE GREAT LAKES REGION AND
CENTRAL APPALACHIANS...WHERE COOL/DRY NORTHWESTERLY FLOW WILL
FOSTER LOCALIZED LAKE EFFECT AND UPSLOPE SNOW SHOWERS.
ALSO...PRECIPITATION FROM A SERIES OF PACIFIC SYSTEMS PROGRESSING
TOWARDS WESTERN CANADA COULD IMPACT THE EXTREME NORTHWESTERN
CORNER OF THE NATION...AND MOISTURE RETURNING NORTH OF A FRONTAL
BOUNDARY PLUNGED IN THE GULF OF MEXICO SHOULD INCREASE THE CHANCE
OF PRECIPITATION OVER SOUTH TEXAS AND FLORIDA NEXT WEEKEND.
INITIALLY MILD CONDITIONS IN THE EAST SHOULD TREND COOLER TOWARDS
THE END OF THE WEEK AS A BROAD TROUGH CARVES OUT ALOFT...WHILE
TEMPERATURES WILL STAY BELOW AVERAGE IN THE WEST UNDER AN UPPER
RIDGE (BUT RATHER STRONG SURFACE HIGH PRESSURE).