Prognostic Meteorological Discussion
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FXUS21 KWNC 222025
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 22 2014

SYNOPSIS: LOW PRESSURE SYSTEMS ARE PREDICTED TO BRING UNSETTLED WEATHER TO NEW
ENGLAND, THE PACIFIC NORTHWEST, AND SOUTHERN FLORIDA, WHILE THE REST OF THE
LOWER 48 IS EXPECTED TO SEE RELATIVELY CALM WEATHER.  NO COLD AIR OUTBREAKS ARE
EXPECTED, AS THE FLOW IS PREDICTED TO COME PRIMARILY OFF THE PACIFIC OCEAN.

HAZARDS

HEAVY RAIN ALONG THE WEST COAST FROM NORTHERN CALIFORNIA TO THE CANADIAN
BORDER, SAT, OCT 25 AND THEN AGAIN, MON-TUE, OCT 27-28.

HIGH WINDS ACROSS THE UPPER MIDWEST AND GREAT LAKES, SUN, OCT 26.

HIGH WINDS ACROSS THE NORTHEAST, MON, OCT 27.

HEAVY RAIN AND SNOW FOR NORTHERN IDAHO AND EXTREME WESTERN MONTANA, SAT, OCT 25
AND AGAIN, MON-TUE, OCT 27-28.

HIGH WINDS AND SIGNIFICANT WAVES FOR THE WESTERN ALASKAN COAST, SUN-MON, OCT
26-27 AND THEN AGAIN WED-THU, OCT 29-30.

HIGH WINDS AND SIGNIFICANT WAVES FOR THE SOUTHWESTERN ALASKAN COAST, WED-THU,
OCT 29-30.

SEVERE DROUGHT FOR THE CENTRAL AND SOUTHERN GREAT PLAINS, SOUTHWEST, SOUTHEAST,
PACIFIC NORTHWEST, GREAT BASIN, AND CALIFORNIA.

DETAILED SUMMARY

FOR SATURDAY OCTOBER 25 - WEDNESDAY OCTOBER 29: A STRONG UPPER-LEVEL TROUGH IS
FORECAST TO MOVE THROUGH SOUTHERN CANADA AND AMPLIFY AS IT MOVES PAST THE GREAT
LAKES AND THE NORTHEAST.  IT`S ASSOCIATED SURFACE LOW IS THEN EXPECTED TO
STRENGTHEN AND INCREASE THE PRESSURE GRADIENT AROUND IT.  THIS STRONG PRESSURE
GRADIENT IS PREDICTED TO LEAD TO HIGH WINDS FOR THE UPPER MIDWEST AND GREAT
LAKES ON THE 26TH AND THE NORTHEAST ON THE 27TH.



THE WEST COAST IS FORECAST TO SEE A NUMBER OF SYSTEMS IMPACTING IT WITH STORMY
WEATHER DURING THIS OUTLOOK PERIOD.  THE FIRST SYSTEM IS AN UPPER-LEVEL TROUGH
MAKING ITS WAY ONSHORE AT THE BEGINNING OF THIS PERIOD.  ADDITIONAL HEAVY RAIN
OF 1 TO 2 INCHES IS POSSIBLE ON THE 25TH.  WITH AT LEAST 5 INCHES OF RAIN
POSSIBLE FROM NOW TO SATURDAY AND 5 TO 10 INCHES THAT HAS FALLEN IN THE PAST 7
DAYS, FLOODING IS POSSIBLE.  AS THIS SYSTEM MOVES INTO THE MIDDLE OF THE
COUNTRY, A BRIEF RESPITE IS EXPECTED FOR THE PACIFIC NORTHWEST AS HIGH PRESSURE
MOVES INLAND FROM THE EASTERN PACIFIC.  AS THIS HIGH PRESSURE CENTER MOVES INTO
THE CENTRAL ROCKIES, MODERATELY STRONG OFFSHORE FLOW IS POSSIBLE FOR SOUTHERN
CALIFORNIA.  WHILE THE MAGNITUDE OF THIS FLOW REMAINS UNCERTAIN, IF IT IS OF
SIGNIFICANT STRENGTH, AN ENHANCED RISK OF WILDFIRES COULD DEVELOP, AS SOILS
REMAIN VERY DRY IN THIS PART OF THE COUNTRY.



LATER IN THE PERIOD, THE REMNANTS OF TROPICAL STORM ANA ARE EXPECTED TO MERGE
WITH AN UPPER-LEVEL TROUGH SOUTH OF ALASKA AND MOVE TOWARDS THE WEST COAST OF
NORTH AMERICA.  WHILE THERE IS SOME MODEL UNCERTAINTY AS TO WHICH LOCATIONS
WILL RECEIVE THE MOST RAINFALL, THERE IS GOOD AGREEMENT ON PARTS OF THE WEST
COAST GETTING AT LEAST ANOTHER 1 TO 2 INCHES OF RAINFALL.



AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE FROM NORTHEASTERN RUSSIA ACROSS THE
BERING SEA.  THE ASSOCIATED SURFACE LOW IS EXPECTED TO DIRECT HIGH WINDS AND
SIGNIFICANT WAVES TO THE WEST COAST OF ALASKA, FROM ABOUT THE KUSKOKWIM DELTA
TO KOTZEBUE SOUND ON THE 26TH AND 27TH.  THIS STORM IS THEN FORECAST TO MOVE
SOUTH AND POTENTIALLY MERGE WITH THE REMNANTS OF ANA BEFORE MOVING ONSHORE
ALONG THE PACIFIC NORTHWEST COAST.  CONCURRENTLY, A VERY STRONG STORM IS
FORECAST TO FORM AND MOVE FROM JUST NORTH OF JAPAN INTO THE BERING SEA.  THIS
STORM IS PREDICTED TO BRING ANOTHER ROUND OF HIGH WINDS AND STRONG WAVES TO THE
WEST COAST OF ALASKA, THIS TIME FROM THE KUSKOKWIM DELTA TO THE EASTERN EDGE OF
THE ALEUTIANS.



TD9 HAS FORMED AND IS FORECAST TO MOVE EASTWARD ACROSS THE YUCATAN PENINSULA.
 A MINORITY OF MODEL SOLUTIONS THEN MOVE IT NORTHEASTWARDS TOWARDS FLORIDA. IF
THIS SOLUTION VERIFIES, IT WOULD BRING HEAVY RAIN, AND STRONG WINDS AND WAVES
TO THE SUNSHINE STATE.  BECAUSE THERE IS A LOT OF UNCERTAINTY WITH THIS
FORECAST, PEOPLE WITH INTERESTS IN FLORIDA AND ALONG THE SOUTHEAST COAST SHOULD
KEEP UPDATED WITH THE MOST CURRENT INFORMATION COMING OUT OF THE NATIONAL
HURRICANE CENTER.

FOR THURSDAY OCTOBER 30 - WEDNESDAY NOVEMBER 05: CONTINUED STRONG WINDS AND
SIGNIFICANT WAVES ARE FORECAST FOR SOUTHWESTERN ALASKA AS A VERY STRONG STORM
IS PREDICTED TO CONTINUE TO BATTER THE COASTLINE.  NO COLD AIR OUBREAKS ARE
PREDICTED FOR THE LOWER 48, AS THE MEAN UPPER-LEVEL PATTERN FAVORS A RIDGE IN
THE MIDDLE OF THE COUNTRY.



THE MOST RECENT DROUGHT MONITOR, RELEASED OCTOBER 16, SHOWS A SLIGHT DECREASE
IN THE AREAL COVERAGE OF SEVERE DROUGHT, FROM 18.6% TO 18.1%.  THERE IS ALSO
THE LOWEST AMOUNT OF AREAL EXTENT WITHOUT ANY LEVEL OF DRYNESS SINCE DECEMBER
2011.

FORECASTER: KENNETH PELMAN

$$




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