Prognostic Meteorological Discussion
Issued by NWS

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FXUS21 KWNC 291942
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 29 2014

SYNOPSIS: AT THE START OF THE PERIOD, SURFACE LOW PRESSURE IS FORECAST TO
DEEPEN OFF THE MID-ATLANTIC/NEW ENGLAND COASTS. COLD HIGH PRESSURE OVER THE
CENTRAL U.S. IS FORECAST TO BUILD IN BEHIND THE AREA OF LOW PRESSURE OFF THE
EAST COAST. AN AREA OF LOW PRESSURE OVER THE CENTRAL GREAT BASIN IS EXPECTED TO
MOVE TO THE NORTHERN PLAINS AS ONSHORE FLOW GETS REESTABLISHED OVER THE PACIFIC
NORTHWEST. SURFACE LOW PRESSURE IS FORECAST NEAR THE ALEUTIANS AND SOUTHERN
COAST OF ALASKA AS HIGH PRESSURE BUILDS OVER THE NORTHERN PART OF THE STATE. BY
MID-PERIOD, A FRONTAL SYSTEM AND AREA OF LOW PRESSURE ARE EXPECTED OVER THE
CENTRAL PART OF THE NATION.

HAZARDS

HEAVY SNOW FOR PARTS OF THE CENTRAL AND SOUTHERN APPALACHIANS, SAT, NOV 1.

HEAVY RAIN FOR PARTS OF EASTERN MAINE, SAT-SUN, NOV 1-2.

HEAVY SNOW FOR PARTS OF THE NORTHEAST, SUN, NOV 2.

HEAVY PRECIPITATION FOR PARTS OF CALIFORNIA, THE CENTRAL GREAT BASIN, NORTHERN
INTERMOUNTAIN WEST, AND NORTHERN ROCKIES, SAT-SUN, NOV 1-2.

HEAVY RAIN FOR PARTS OF THE OHIO VALLEY, CENTRAL AND SOUTHERN PLAINS, MIDDLE
AND LOWER MISSISSIPPI VALLEY, AND SOUTHWEST, TUE-WED, NOV 4-5.

HEAVY PRECIPITATION FOR PARTS OF THE PACIFIC NORTHWEST, MON-TUE, NOV 3-4.

MUCH BELOW NORMAL TEMPERATURES FOR PARTS OF THE OHIO AND TENNESSEE VALLEYS,
MIDDLE AND LOWER MISSISSIPPI VALLEY, CENTRAL AND SOUTHERN APPALACHIANS,
MID-ATLANTIC, AND SOUTHEAST, SAT-MON, NOV 1-3.

HIGH WINDS FOR PARTS OF THE GREAT LAKES, CENTRAL APPALACHIANS, NORTHEAST, AND
ALONG MUCH OF THE EAST COAST, SAT-MON, NOV 1-3.

HIGH WINDS FOR PARTS OF THE ALEUTIANS AND COASTAL SECTIONS OF WESTERN ALASKA,
SAT-MON, NOV 1-3.

HIGH WINDS FOR PARTS OF THE NORTH SLOPE OF ALASKA, SAT-TUE, NOV 1-4.

SIGNIFICANT WAVES FOR PARTS OF THE ALEUTIANS, SAT, NOV 1.

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

DETAILED SUMMARY

FOR SATURDAY NOVEMBER 01 - WEDNESDAY NOVEMBER 05: LOW PRESSURE IS FORECAST TO
DEEPEN OFF THE MID-ATLANTIC AND NEW ENGLAND COASTS SAT-SUN AS COLD HIGH
PRESSURE BUILDS OVER THE EAST-CENTRAL CONUS. THIS IS EXPECTED TO LEAD TO HEAVY
SNOW (IN EXCESS OF 4 INCHES IN 24 HOURS) FOR PARTS OF THE CENTRAL AND SOUTHERN
APPALACHIANS SAT, HEAVY RAIN (IN EXCESS OF 1 INCH IN 24 HOURS) FOR PARTS OF
EASTERN MAINE SAT-SUN, AND HEAVY SNOW (IN EXCESS OF 4 INCHES IN 24 HOURS) FOR
PARTS OF THE NORTHEAST SUN. MUCH BELOW NORMAL TEMPERATURES (8-12 DEGREES BELOW
NORMAL) FOR PARTS OF THE OHIO AND TENNESSEE VALLEYS, MIDDLE AND LOWER
MISSISSIPPI VALLEY, CENTRAL AND SOUTHERN APPALACHIANS, MID-ATLANTIC, AND
SOUTHEAST SAT-MON, AS WELL AS HIGH WINDS (IN EXCESS OF 30 KNOTS) FOR PARTS OF
THE GREAT LAKES, CENTRAL APPALACHIANS, NORTHEAST, AND ALONG MUCH OF THE EAST
COAST SAT-MON CAN ALSO BE EXPECTED.



LOW PRESSURE ANTICIPATED OVER THE CENTRAL GREAT BASIN IS FORECAST TO CAUSE
HEAVY PRECIPITATION (RAINFALL IN EXCESS OF 1 INCH IN 24 HOURS AT LOWER
ELEVATIONS, SNOWFALL IN EXCESS OF 4 INCHES IN 24 HOURS AT HIGHER ELEVATIONS)
FOR PARTS OF CALIFORNIA, THE CENTRAL GREAT BASIN, NORTHERN INTERMOUNTAIN WEST,
AND NORTHERN ROCKIES SAT-SUN.



ONSHORE FLOW IS EXPECTED TO GET REESTABLISHED OVER THE PACIFIC NORTHWEST
LEADING TO HEAVY PRECIPITATION (RAINFALL IN EXCESS OF 1 INCH IN 24 HOURS AT
LOWER ELEVATIONS, SNOWFALL IN EXCESS OF 4 INCHES IN 24 HOURS) AT HIGHER
ELEVATIONS) FOR PARTS OF THE PACIFIC NORTHWEST MON-TUE.



DEEP LOW PRESSURE OVER THE ALEUTIANS AND SOUTH COAST OF ALASKA LEADS TO HIGH
WINDS (IN EXCESS OF 30 KNOTS) FOR PARTS OF THE ALEUTIANS AND COASTAL SECTIONS
OF WESTERN ALASKA SAT-MON. THIS SCENARIO ALSO LEADS TO THE POSSIBILITY OF
SIGNIFICANT WAVES (WAVE HEIGHTS IN EXCESS OF 20 FEET) FOR PARTS OF THE
ALEUTIANS SAT. HIGH PRESSURE BUILDING NORTH OF ALASKA LEADS TO HIGH WINDS (IN
EXCESS OF 30 KNOTS) FOR PARTS OF THE NORTH SLOPE OF ALASKA SAT-TUE.



AN AREA OF LOW PRESSURE FORECAST TO DEVELOP OVER THE SOUTHERN PLAINS IS
EXPECTED TO DRAW TROPICAL MOISTURE ACROSS MEXICO AND FROM THE GULF OF MEXICO.
THIS IS FORECAST TO LEAD TO HEAVY RAIN (IN EXCESS OF 1 INCH IN 24 HOURS) FOR
PARTS OF THE OHIO VALLEY, CENTRAL AND SOUTHERN PLAINS, MIDDLE AND LOWER
MISSISSIPPI VALLEY, AND SOUTHWEST TUE-WED.



HIGH PRESSURE BUILDING OVER THE WESTERN CONUS ON MON-TUE LEADS TO DOWNSLOPING
OFF-SHORE FLOW. HIGH WINDS ARE POSSIBLE FOR COASTAL SECTIONS OF CENTRAL AND
SOUTHERN CALIFORNIA SAT-SUN, BUT MODEL UNCERTAINTY PRECLUDES THE SPECIFICATION
OF A HAZARD AT THE CURRENT TIME.

FOR THURSDAY NOVEMBER 06 - WEDNESDAY NOVEMBER 12: A LOW AMPLITUDE, MOSTLY ZONAL
FLOW PATTERN IS ANTICIPATED ACROSS MOST OF THE CONUS WHICH SUGGESTS THE AIR
MASSES OVER THE COUNTRY WILL LARGELY BE OF PACIFIC ORIGIN. NO HAZARD AREAS CAN
CURRENTLY RELIABLY BE SPECIFIED.



THE MOST RECENT DROUGHT MONITOR, RELEASED OCTOBER 23, SHOWS A SLIGHT DECREASE
IN THE AREAL COVERAGE OF SEVERE DROUGHT, FROM 18.01% TO 18.0%. THERE IS ALSO
THE LARGEST AMOUNT OF AREAL EXTENT WITHOUT ANY LEVEL OF DRYNESS SINCE DECEMBER
2011.

FORECASTER: RANDY SCHECHTER

$$




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