Prognostic Meteorological Discussion
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000
FXUS02 KWBC 021601
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1200 PM EDT MON MAY 02 2016

VALID 12Z THU MAY 05 2016 - 12Z MON MAY 09 2016

GENERAL FLOW PATTERN
~~~~~~~~~~~~~~~~~~~~
A MID-LATITUDE OMEGA STYLE BLOCK BREAKS DOWN THIS WEEKEND AS A
LARGE CLOSED LOW DEVELOPS ACROSS ERN CANADA...ENGULFING THE ERN US
DEEP CYCLONE.  MEANWHILE...A SLOWLY PROGRESSIVE RIDGE MOVES OVER
THE ERN PACIFIC AS A LEAD WRN US CLOSED LOW GRADUALLY WORKS INTO
THE PLAINS. THE BIGGEST FLY IN THE OINTMENT LIES ACROSS WRN CANADA
AND OFFSHORE THE NORTHWEST...WHERE GUIDANCE REMAINS OUT OF PHASE.


MODEL PREFERENCES
~~~~~~~~~~~~~~~~~
THE 00 UTC GFS/ECMWF AND 00 UTC GEFS/NAEFS/ECMWF ENSEMBLE MEANS
SOLUTIONS GENERALLY SEEM REASONABLY WELL CLUSTERED INTO THU/FRI
AND A COMPOSITE SOLUTION SEEMS FINE BEYOND MORE UNCERTAIN SMALLER
FOCUS. THE 06 UTC GFS/GEFS SEEM LESS IN LINE. INCREASING FORECAST
SPREAD AND PATTERN TRANSITION THEN SUPPORTS AN ENSEMBLE MEAN
FORECAST APPROACH FROM THE WEEKEND INTO EARLY NEXT WEEK AS PER THE
WPC PRODUCT SUITE...USING THE AFOREMENTIONED 00 UTC SUITE.


WEATHER HIGHLIGHTS/THREATS
~~~~~~~~~~~~~~~~~~~~~~~~~~
A DEEP LOW/TROUGH WORKING GRADUALLY OVER THE WEST WILL SPREAD A
BROAD AREA OF RAIN AND HIGHER ELEVATION SNOWS FROM THE WEST COAST
INTO THE ROCKIES...WITH LEAD RAINS DEVELOPING OVER THE CENTRAL US
THIS WEEKEND INTO NEXT MONDAY. HIGHEST TOTALS ARE EXPECTED FROM
FAVORED SIERRA NEVADA AND INTERMOUNTAIN WEST TERRAIN INTO PORTIONS
OF CO/WY THEN OUT OVER THE PLAINS. TEMPERATURES WITH THE SYSTEM
ARE EXPECTED TO BE UPWARDS OF 10F BELOW NORMAL. RIDGING ALOFT
AHEAD OF THIS SYSTEM IS EXPECTED TO MEANWHILE SUPPORT LEAD WARMING
SPREADING FROM THE ROCKIES THU TO THE CENTRAL THEN ERN US SAT-MON.

AMPLIFIED MEAN UPPER TROUGHING AND INDIVIDUALLY UNCERTAIN FOCUS
WITH MULTIPLE EAST COAST/WRN ATLANTIC SURFACE LOWS WILL GENERALLY
SUPPORT COOL AND UNSETTLED WEATHER OVER THE EAST THU INTO THE
WEEKEND. MUCH OF THE PRECIPITATION MAY FALL OVER THE MID-ATLANTIC
STATES THU-SAT IN CLOSEST PROXIMITY TO LOW SUPPORT AND OVER THE
NRN TIER WITH SECONDARY COOL SURGES.

SCHICHTEL

$$




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