Analyzed 06Z Mon Oct 24, 2016
Valid 12Z Mon Oct 24, 2016
Valid 18Z Mon Oct 24, 2016
Valid 00Z Tue Oct 25, 2016
Valid 06Z Tue Oct 25, 2016
Valid 12Z Tue Oct 25, 2016
Valid 00Z Wed Oct 26, 2016
Valid 12Z Wed Oct 26, 2016
Valid 12Z Thu Oct 27, 2016
Valid 12Z Fri Oct 28, 2016
Valid 12Z Sat Oct 29, 2016
Valid 12Z Sun Oct 30, 2016
Valid 12Z Mon Oct 31, 2016
+ 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
327 AM EDT Mon Oct 24 2016
Valid 12Z Mon Oct 24 2016 - 12Z Wed Oct 26 2016
...Fall-like weather continues across much of the nation...
...Strong low pressure system approaching the Pacific Northwest...
A large high pressure area moving southeast out of southern Canada
Monday will bring pristine fall weather to the eastern half of the
nation behind a reinforcing cold front. Scattered showers are
possible near the Great Lakes, and snow showers for the higher
elevations of New England with below normal temperatures in place
over that region. Locations farther south should have a dry
frontal passage with a slight drop in temperatures. Warm and dry
conditions are expected to continue for the Gulf Coast region and
Deep South through Tuesday with mostly sunny skies and ongoing
Unsettled weather over the eastern Pacific with a deep low
pressure system offshore is expected to bring periods of rain to
the Pacific Northwest early this week. Additional showers and
storms are likely to develop over the Intermountain West, with
snow for the highest mountains. Windy conditions are also
expected for coastal areas from northern California to Washington
By Wednesday morning, surface cyclogenesis over the Midwest states
is expected to result in numerous showers and some storms. Strong
thunderstorms are possible south of the warm front that will lift
northward towards the Ohio Valley, and a cold rain across
Wisconsin and Michigan.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php
+ Additional Links
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
251 AM EDT MON OCT 24 2016
VALID 12Z THU OCT 27 2016 - 12Z MON OCT 31 2016
...OVERVIEW AND GUIDANCE/UNCERTAINTY ASSESSMENT...
THE LARGE SCALE PATTERN ALOFT SHOULD CONTINUE TO BE DOMINATED BY
AN AMPLIFIED ERN PACIFIC TROUGH/W-CNTRL U.S. RIDGE
CONFIGURATION... WITH A MIGRATORY TROUGH CROSSING THE NORTHEAST
CORNER OF THE COUNTRY. A CLOSED ANTICYCLONE OVER THE SOUTHERN
ROCKIES AND PLAINS PERSISTS FOR MOST OF THE FORECAST PERIOD. DUE
TO CONSIDERABLE SPREAD IN SOLUTIONS AMONG THE MODELS/ENSEMBLE
MEMBERS...CONFIDENCE IS BELOW NORMAL FOR DAYS 5-7 ACROSS THE UPPER
MS VALLEY/GREAT LAKES/OH VALLEY AND MID ATLANTIC/NEW ENGLAND.
FOR DAYS 3-4 SOLNS ARE STILL CLUSTERED WELL FOR THE SYSTEM HEADING
ACROSS THE GREAT LAKES AND THEN INTO NEW YORK AND NEW ENGLAND.
AGREEMENT BREAKS DOWN ONCE THIS SYSTEM DEPARTS.
GUIDANCE DISPLAYS CLUSTERING FOR SIGNIFICANT FEATURES THROUGH DAY
3 WED BUT THEN QUICKLY DIVERGES FOR SHRTWV DETAILS WITHIN THE ERN
PAC TROUGH. HANDLING OF WAVES EJECTING FROM THE EASTERN PACIFIC
TROUGH DIFFER FROM ONE MODEL/ENSEMBLE CLUSTER TO ANOTHER.
FOR EXAMPLE...THE LAST FEW RUNS OF THE GFS AND NOW THE 00Z
CANADIAN GLOBAL HAVE AMPLIFIED NORTHERN STREAM ENERGY COMING
ONSHORE AND THEN CARRY A MORE AMPLIFIED TROUGH CROSSING THE
NORTHERN ROCKIES/PLAINS THU-FRI AND BEYOND.
THE 12Z ECMWF MOVED A ROSSBY WAVE IN THE SOUTHERN STREAM PORTION
OF THE EASTERN PACIFIC TROUGH AND MOVED IT OVER THE TOP OF THE
WESTERN RIDGE AND THEN AMPLIFIED THE WAVE AS IT SAME INTO THE
EASTERN US TROUGH. MOST OF THE ECMWF ENSEMBLE MEMBERS DID NOT
REPLICATE THE BEHAVIOR WITH THE WAVE WEAKENING AS IT CRESTED THE
WESTERN US RIDGE. AS A RESULT OF THE DEAMPLIFICATION OF THE WAVE
AS USUALLY HAPPENS CROSSING A MEAN RIDGE...MORE WEIGHTING WAS
GIVEN TO THE ENSEMBLE MEAN SOLUTION.
THE 00Z ECMWF HAS NOW SHIFTED MORE TOWARDS THE IDEA OF THE
NORTHERN STREAM PORTION OF THE TROUGH COMING ASHORE IN THE PACIFIC
NORTHWEST AND THIS WAVE CROSSING THE NORTHERN TIER...INCLUDING THE
GREAT LAKES/NEW YORK/NEW ENGLAND ON SAT. THIS BRINGS THE ECMWF
CLOSER TO THE GFS SOLUTION. AS A RESULT THE ECMWF HAS BACKED ON
THE 12Z RUN AND NOW DOES NO AMPLIFY THE TROUGH AS MUCH CROSSING
THE MS VALLEY/OH VALLEY/CENTRAL APPALACHIANS/MID ATLANTIC.
CONTINUE TO EXPECT A BROAD AREA OF VERY WARM TEMPS AVERAGING
10-20F ABOVE NORMAL FROM THE CNTRL-SRN ROCKIES ACROSS THE PLAINS
AND INTO THE SOUTHEAST.A FEW RECORD HIGH TEMPERATURES ARE EXPECTED
IN THESE AREAS. HIGHEST ANOMALIES MAY BE OVER THE CNTRL PLAINS
WITH SOME DEPARTURES FROM NORMAL FOR HIGHS PSBLY EXCEEDING PLUS
CLOUDS/PCPN SHOULD KEEP THE WEST COAST STATES BELOW NORMAL. MEAN
CYCLONIC FLOW ALOFT... AND SPECIFICALLY COOL ERN HIGH PRESSURE AND
TRAILING MIDWEST TO NEW ENGLAND LOW PRESSURE SHOULD SUPPORT NEAR
TO BELOW NORMAL TEMPS OVER THE NERN QUADRANT OF THE COUNTRY.
AS THE EASTERN PACIFIC CYCLONE IS SLOW TO MOVE ONSHORE...MUCH OF
THE PCPN WILL FOCUS IN CALIFORNIA NORTHERN TO WESTERN OR AND WA.
THE MAIN PCPN FOCUS OVER THE EAST WILL BE WITH A SWATH OF MODERATE
RAINS FROM THE UPR MS VLY/GRTLKS AND ACROSS THE NORTHEAST
ACCOMPANYING MIDWEST TO NEW ENGLAND LOW PRESSURE. THERE IS
POTENTIAL FOR SOME PCPN TO FALL IN THE FORM OF SNOW IN THE HIGHER
ELEVS OF INTERIOR NEW ENGLAND. SHOWERS ARE PSBL IN THE SOUTHEAST
FL PENINSULA AND FL KEYS.