927
FXUS01 KWBC 011946
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
345 PM EDT MON MAY 01 2023
VALID 00Z TUE MAY 02 2023 - 00Z THU MAY 04 2023
...HEAVY SNOW WILL PERSIST ACROSS UPPER PENINSULA OF MICHIGAN
THROUGH EARLY WORK WEEK...
...WELL-BELOW-AVERAGE TEMPERATURES SPREAD FROM GREAT LAKES/MIDWEST
INTO NORTHEAST/MID-ATLANTIC ON WEDNESDAY, WITH SNOW CHANCES IN
HIGHER TERRAIN...
...COOL AND UNSETTLED WEATHER SPREADS INTO THE WEST COAST, WITH
WELL ABOVE AVERAGE TEMPERATURES CONTINUE ACROSS THE INTERMOUNTAIN
WEST, NORTHERN/CENTRAL ROCKIES, AND NORTHERN HIGH PLAINS...
A LATE-SEASON SNOWSTORM IS CURRENTLY ONGOING ACROSS PORTIONS OF
THE UPPER GREAT LAKES AS A VERY STRONG, NEARLY STATIONARY
UPPER-LEVEL LOW PRESSURE SYSTEM CHURNS OVER THE REGION. IN
ADDITION TO THIS SYSTEM CAUSING NEAR RECORD-LOW PRESSURES DURING
THE MONTH OF MAY, IT IS ALSO RESPONSIBLE FOR BRINGING A VERY COOL
AIRMASS OVER THE REGION. SURFACE TEMPERATURES UNDER THIS AREA OF
LOW PRESSURE RANGE FROM 10-20F BELOW AVERAGE, COLD ENOUGH FOR SNOW
TO FALL OVER THIS AREA. GUSTY, NORTHERLY FLOW ON THE BACKSIDE OF
THE STRONG SURFACE LOW IN CONJUNCTION WITH COLD AIR BEING PUSHED
SOUTHWARD WILL LEAD TO ADDITIONAL SNOWFALL OF 4-8", LOCALLY 1+
FEET OVER HIGHER ELEVATIONS OF MICHIGAN'S UPPER PENINSULA.
NEAR-FREEZING SURFACE TEMPERATURES WILL RESULT IN FALLING SNOW
BEING WET AND HEAVY, WHICH MAY RESULT IN DOWNED TREES AND POWER
LINES. ON TUESDAY, THE SNOWFALL COVERAGE WILL DIMINISH AS THIS
SYSTEM BEGINS TO WEAKEN AND EXITS TOWARD THE EAST. TEMPERATURES
ARE EXPECTED TO GRADUALLY WARM THROUGHOUT THE WEEK, WITH SEASONAL
TEMPERATURES EXPECTED FOR THE AREA BY LATE-WEEK.
CONDITIONS ACROSS THE MID-ATLANTIC AND NORTHEAST ARE EXPECTED TO
BE DRIER, BUT COOLER AFTER THE WIDESPREAD HEAVY RAINFALL OVER THE
WEEKEND. THE HEAVIEST AXIS OF PRECIPITATION WILL PROGRESS
NORTHWARD FROM FAR NORTHERN MAINE INTO SOUTHERN QUEBEC MONDAY
NIGHT, LEAVING DRIER CONDITIONS IN ITS WAKE. HOWEVER, THE LOW
PRESSURE SYSTEM LOCATED OVER THE GREAT LAKES WILL GRADUALLY
PROPAGATE EAST-SOUTHEASTWARD TOWARD THE NORTHEAST THIS WEEK,
BRINGING ITS VERY COOL AIRMASS ALONG WITH IT. WHILE TEMPERATURES
WILL BE BELOW AVERAGE TO BEGIN THE WEEK, IT WILL GET EVEN COLDER.
BY WEDNESDAY, SURFACE TEMPERATURES WILL BE PARTICULARLY COOL AS
THE UPPER-LEVEL LOW SLOWLY MOVES ACROSS UPSTATE NEW YORK. HIGH
TEMPERATURES WILL ONLY IN PEAK IN THE 40S AND 50S OVER MUCH OF THE
NORTHEAST AND MID-ATLANTIC ON WEDNESDAY, WHICH IS 15-20F BELOW
AVERAGE. IN ADDITION TO THE COOL TEMPERATURES, THE MAIN BAND OF
PRECIPITATION IS EXPECTED TO WRAP AROUND THE SOUTH SIDE OF THE
UPPER-LEVEL LOW ON MONDAY/TUESDAY, BRINGING RAIN CHANCES INTO THE
OHIO RIVER VALLEY AND INTO PORTIONS OF THE MID-ATLANTIC/NORTHEAST.
WHILE MOST OF THE PRECIPITATION WILL FALL AS RAIN, SOME AREAS,
PARTICULARLY AT HIGHER ELEVATIONS, ARE EXPECTED TO SEE
ACCUMULATING SNOW AS WELL. THE CENTRAL APPALACHIANS ARE EXPECTED
TO SEE THE MOST SNOW, WITH SNOWFALL TOTALS RANGING FROM 6-10",
WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
IN THE WEST, AN UNSETTLED WEATHER PATTERN IS ENTERING THE AREA AS
AN UPPER-LEVEL LOW PRESSURE SYSTEM PROPAGATES SOUTHWARD ALONG THE
WEST COAST. INITIALLY, IMPACTS WILL BE CONFINED TO AREAS WEST OF
THE SIERRA NEVADA AND PORTIONS OF WESTERN OREGON/WASHINGTON. THE
MAIN IMPACTS WILL BE WELL-BELOW AVERAGE TEMPERATURES, SCATTERED
SHOWERS, AND HIGHER-ELEVATION SNOW. THIS SYSTEM WILL PROGRESS
SOUTHWARD ALONG THE WEST COAST DURING THE EARLY-WEEK. BY MID-WEEK,
THIS SYSTEM WILL BEGIN PROPAGATING EASTWARD INTO THE DESERT
SOUTHWEST AND PORTIONS OF THE SOUTHERN ROCKIES, COOLING DOWN
TEMPERATURES SIGNIFICANTLY ACROSS THE REGION. FOR PORTIONS OF THE
INTERMOUNTAIN WEST AND CENTRAL/NORTHERN HIGH PLAINS, WELL-ABOVE
AVERAGE TEMPERATURES ARE EXPECTED THIS WEEK, WITH MANY HIGHS OVER
THE AREA IN THE 70S AND 80S. CONDITIONS WILL BE MOSTLY DRY ACROSS
THIS REGION, MINUS A CHANCE OF SCATTERED THUNDERSTORMS OVER
PORTIONS OF THE NORTHERN/CENTRAL ROCKIES ON TUESDAY. REGIONS IN
THE GREAT BASIN THAT ARE EXPERIENCING RIVER FLOODING DUE TO RAPID
SNOW MELT CAN EXPECT MORE SIGNIFICANT SNOWMELT THIS WEEK GIVEN THE
WARM TEMPERATURES OVERSPREADING THE REGION.
GENZ
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page