Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2
000
FXUS21 KWNC 051927
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST FEBRUARY 05 2016

SYNOPSIS: AN AREA OF UPPER-LEVEL LOW PRESSURE IS FORECAST TO STRENGTHEN ACROSS
THE EASTERN U.S. EARLY IN THE PERIOD. A STRONG LOW PRESSURE SYSTEM IS EXPECTED
TO MOVE TOWARDS THE CANADIAN MARITIMES ON MONDAY. ANOTHER SURFACE LOW IS
EXPECTED TO QUICKLY DEVELOP NEAR THE MID-ATLANTIC COAST ON MONDAY NIGHT WITH A
SUBSEQUENT TRACK OFFSHORE OF NEW ENGLAND. SURFACE HIGH PRESSURE IS EXPECTED TO
PREVAIL ACROSS THE WESTERN U.S. DURING THE SECOND WEEK OF FEBRUARY. AN AREA OF
UPPER-LEVEL LOW PRESSURE IS FORECAST TO PERSIST ACROSS THE ALEUTIANS DURING THE
NEXT TWO WEEKS.

HAZARDS

LOCALLY HEAVY, LAKE-EFFECT SNOW DOWNWIND OF LAKE SUPERIOR AND NORTHERN LAKE
MICHIGAN, MON, FEB 8-9.

POTENTIAL FOR HEAVY SNOW ACROSS THE CENTRAL AND SOUTHERN APPALACHIANS,
MID-ATLANTIC, AND NORTHEAST, MON-TUE, FEB 8-9.

HIGH WINDS FOR EASTERN LONG ISLAND AND SOUTHEAST NEW ENGLAND, MON, FEB 8.

HIGH WINDS FOR THE GREAT PLAINS AND PARTS OF THE MISSISSIPPI VALLEY, MON, FEB 8.

MUCH BELOW-NORMAL TEMPERATURES FOR PARTS OF THE SOUTHEAST, TUE-THU, FEB 9-11.

FLOODING OCCURRING OR LIKELY ACROSS PARTS OF THE SOUTHEAST, LOWER MISSISSIPPI
VALLEY, AND NORTHEAST TEXAS.

SLIGHT CHANCE FOR MUCH BELOW NORMAL TEMPERATURES FOR THE GREAT LAKES,
NORTHEAST, AND MID-ATLANTIC, SAT-SUN, FEB 13-14.

SEVERE DROUGHT ACROSS PARTS OF THE WESTERN U.S. AND PUERTO RICO.

DETAILED SUMMARY

FOR MONDAY FEBRUARY 08 - FRIDAY FEBRUARY 12: A HIGHLY AMPLIFIED UPPER-LEVEL
PATTERN IS FORECAST WITH A RIDGE (TROUGH) OVER WESTERN (EASTERN) NORTH AMERICA.
THE AMPLIFYING UPPER-LEVEL TROUGH IS EXPECTED TO PROMOTE SURFACE LOW
DEVELOPMENT NEAR THE MID-ATLANTIC COAST ON MONDAY NIGHT. A SWATH OF MODERATE TO
HEAVY SNOW (3 TO 6 INCHES, OR MORE) MAY ACCOMPANY THE AMPLIFYING TROUGH AND ITS
COASTAL LOW PRESSURE SYSTEM FROM THE MID-ATLANTIC NORTH TO NEW ENGLAND. MODEL
GUIDANCE CONTINUES TO VARY ON THE LOCATION OF HEAVIEST SNOWFALL. THE 6Z GFS AND
0Z ECMWF ENSEMBLE MEAN SOLUTIONS ON FEBRUARY 5 INDICATE A BROAD AREA OF MORE
THAN 0.25 INCHES, LIQUID EQUIVALENT, FROM VIRGINIA NORTH TO MAINE FROM FEBRUARY
8 THROUGH 9. THESE PRECIPITATION FORECASTS ARE A FUNCTION OF THE BROAD RANGE OF
SOLUTIONS FROM THE ENSEMBLE MEMBERS AND ALSO INDICATE THAT THE FAST MOVEMENT OF
THE LOW PRESSURE SYSTEM WILL LIMIT SNOWFALL ACCUMULATIONS. SINCE PREDICTABILITY
REMAINS LOW ON THE EXACT SWATH OF HEAVIEST SNOWFALL ACROSS THE MID-ATLANTIC AND
NORTHEAST, PLEASE REFER TO THE LATEST FORECASTS FROM LOCAL NWS OFFICES.



RESIDENTS OF SOUTHEAST NEW ENGLAND ARE ALSO URGED TO MONITOR THE LATEST
FORECASTS REGARDING A STRONG LOW PRESSURE SYSTEM FORECAST TO MOVE OFFSHORE OF
THE EAST COAST FROM SUNDAY NIGHT INTO MONDAY. THE LATEST MODEL GUIDANCE FAVORS
A TRACK WHICH WOULD KEEP THE HEAVIEST PRECIPITATION OFFSHORE OF NEW ENGLAND.
HOWEVER, A SLIGHT DEVIATION TO THE NORTHWEST COULD BRING HEAVIER SNOW TO NEW
ENGLAND ON MONDAY. EVEN WITH A TRACK WELL OFFSHORE, STRONG WINDS (MORE THAN 30
KNOTS) ARE EXPECTED ACROSS EASTERN LONG ISLAND AND SOUTHEAST NEW ENGLAND ON
MONDAY MORNING.



ARCTIC AIR ENTERING THE LOWER 48 IS EXPECTED TO RESULT IN LAKE-ENHANCED SNOW
WITH LOCALLY HEAVY AMOUNTS MOST LIKELY DOWNWIND OF LAKE SUPERIOR AND NORTHERN
LAKE MICHIGAN THROUGH AT LEAST TUESDAY. STRONG, COLD AIR ADVECTION COUPLED WITH
UPSLOPE FLOW IS EXPECTED TO BRING HEAVY SNOW (4 INCHES OR MORE) TO THE CENTRAL
AND SOUTHERN APPALACHIANS ON MONDAY AND TUESDAY. A TIGHT PRESSURE GRADIENT IS
EXPECTED TO RESULT IN HIGH WINDS (MORE THAN 30 KNOTS) ACROSS THE GREAT PLAINS
AND PARTS OF THE MISSISSIPPI VALLEY ON MONDAY.



SURFACE HIGH PRESSURE, ORIGINATING FROM CANADA, IS FORECAST TO SHIFT INTO THE
SOUTHEAST DURING MID-WEEK. MUCH BELOW-NORMAL TEMPERATURES (12 DEGREES F OR
MORE) ARE LIKELY TO BRIEFLY AFFECT THE SOUTHEAST FROM TUESDAY THROUGH THURSDAY.
FREEZING TEMPERATURES MAY EXTEND AS FAR SOUTH AS THE NORTHERN FLORIDA PENINSULA
ON WEDNESDAY AND THURSDAY MORNINGS. A MODERATION IN TEMPERATURES IS EXPECTED ON
FRIDAY ACROSS THE SOUTHEAST.



AN AMPLIFIED RIDGE ALOFT IS LIKELY TO RESULT IN AN EXTENDED PERIOD OF DRY
WEATHER AND ABOVE-NORMAL TEMPERATURES ACROSS MUCH OF THE WESTERN U.S. ALTHOUGH
NOT CONSIDERED HAZARDOUS, RECORD HIGHS ARE POSSIBLE EARLY IN THE WEEK ACROSS
CALIFORNIA.



HEAVY RAINFALL DURING THE PAST FEW WEEKS TRIGGERED MINOR TO MODERATE FLOODING
ALONG THE FOLLOWING RIVERS: ALTAMAHA AND SAVANNAH RIVERS IN GEORGIA, EDISTO
RIVER IN SOUTH CAROLINA, CHOCTAWHATCHEE RIVER IN THE FLORIDA PANHANDLE, PEARL
RIVER IN MISSISSIPPI, AND SULPHUR RIVER IN NORTHEAST TEXAS. FLOODING ALONG
THESE RIVERS IS EXPECTED TO LINGER THROUGH AT LEAST FEBRUARY 8.



A PERSISTENT AREA OF LOW PRESSURE AND ONSHORE FLOW ARE EXPECTED TO BRING
PERIODS OF PRECIPITATION TO SOUTHEAST ALASKA AND THE ALASKA PANHANDLE DURING
THIS PERIOD. ALTHOUGH AMOUNTS ARE NOT EXPECTED TO REACH HAZARDS CRITERIA,
ABOVE-AVERAGE PRECIPITATION CAN BE EXPECTED.

FOR SATURDAY FEBRUARY 13 - FRIDAY FEBRUARY 19: THE 6Z GFS AND 0Z ECMWF ENSEMBLE
MEANS AND THEIR ENSEMBLE MEMBERS VARY ON THE AMPLITUDE OF THE UPPER-LEVEL
PATTERN ACROSS NORTH AMERICA DURING WEEK-2. AN UPPER-LEVEL RIDGE OVER THE
WESTERN U.S. IS EXPECTED TO MAINTAIN A RELATIVELY DRY PATTERN ACROSS CALIFORNIA
AND THE INTERIOR WEST. THE TEMPERATURE OUTLOOK ACROSS THE EASTERN U.S. IS
DEPENDENT ON THE DEPTH OF THE TROUGH OVER EASTERN NORTH AMERICA. A SLIGHT RISK
OF MUCH-BELOW NORMAL TEMPERATURES IS POSTED FOR THE GREAT LAKES AND NORTHEAST
ON FEBRUARY 13 AND 14 BASED ON RECENT DETERMINISTIC MODEL RUNS INDICATING A
SECONDARY OUTBREAK OF ARCTIC AIR EARLY IN WEEK-2. ALSO, THE GEFS REFORECAST
TEMPERATURE TOOL INDICATES A 20 TO 40 PERCENT CHANCE OF MINIMUM TEMPERATURES
FALLING BELOW THE 15TH PERCENTILE ACROSS THESE AREAS.



ACCORDING TO THE U.S. DROUGHT MONITOR VALID ON FEBRUARY 2, THE COVERAGE OF
SEVERE TO EXCEPTIONAL (D2-D4) DROUGHT ACROSS THE 50 U.S. STATES AND PUERTO RICO
DECREASED SLIGHTLY FROM 7.13 PERCENT TO 7.06 PERCENT. SEVERE TO EXCEPTIONAL
DROUGHT IS LIMITED TO THE WESTERN THIRD OF THE CONTIGUOUS U.S. AND PUERTO RICO.

FORECASTER: BRAD PUGH

$$



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.