Quantitative Precipitation Forecast
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
000
FOUS11 KWBC 051928
QPFHSD

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
328 PM EDT TUE MAY 05 2015

VALID 00Z WED MAY 06 2015 - 00Z SAT MAY 09 2015


...DAY 1...

...COLORADO/WYOMING ROCKIES...

A 700 MB FRONT WITH POSSIBLE EMBEDDED CIRCULATIONS IS EXPECTED TO
DRIFT EAST ACROSS WYOMING AND COLORADO.  CURRENT MODEL FCSTS SHOW
ONE BURST OF VERTICAL MOTIONS WITH THE PRIMARY FRONT THIS
EVENING...WITH A SECONDARY MAXIMA OF MODEST ASCENT WITH A
FOLLOWING SECOND BNDRY-700 MB TROUGH ON WED. THREAT FOR
SIGNIFICANT SNOW ACCUMULATIONS IS EXPECTED TO REMAIN AT ELEVATIONS
AT OR ABOVE 9000 FT IN SOUTHWESTERN AND CENTRAL CO/RANGES OF
CENTRAL TO NORTHEAST WY...AND UINTAS OF UT.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.

...DAY 2...

...CA/GREAT BASIN/WY-ID ROCKIES...

THE MODELS/ENSEMBLES SHOW A 700 MB LOW FORMING IN NV AND DRIFTING
SOUTH TO NEAR THE CA BORDER THU EVENING.  WELL DEFINED 700 MB
CONVERGENCE NEAR THE CIRCULATION CENTER AND MOISTURE INTERACTING
WITH AREAS OF ENHANCED DIVERGENCE SUPPORT HIGHER ELEVATION SNOWS
IN THE RANGES OF NORTHERN TO CENTRAL NV WEST INTO THE CENTRAL CA
SIERRA NEVADA RANGE.  DEEP SOUTHERLY FLOW AHEAD OF THE LOW IS
EXPECTED TO ADVECT AMPLE MOISTURE INTO EASTERN ID AND NORTHWESTERN
WY...WHERE UPPER DIVERGENCE MAXIM AND LOW LEVEL FRONTAL
CONVERGENCE ENHANCES SNOW IN THE TERRAIN NEAR THE ID/MT BORDER.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.

...DAY 3...

...CA SIERRA/GREAT BASIN/CENTRAL ROCKIES...

SNOWS ARE EXPECTED TO CONTINUE THE FIRST PART OF DAY 3 UNTIL THE
700 MB LOW STARTS DRIFTING EAST...WITH THE UPPER DIVERGENCE/LOWER
CONVERGENCE AREAS MOVING EAST ACROSS THE GREAT BASIN IN TANDEM
WITH THE CIRCULATION CENTER. CONTINUING LOW LEVEL SOUTHERLY FLOW
EAST OF THE CIRCULATION INTO THE CO ROCKIES SUPPORTS ADDITIONAL
ACCUMULATIONS AT HIGHER ELEVATIONS.   DAYS 1-3 TOTALS SHOULD
PROVIDE SEVERAL INCHES OF SNOW TO THE CENTRAL-SOUTH CENTRAL CA
SIERRA AND ALSO IN THE RANGES FROM SOUTHWEST TO CENTRAL CO AND
NORTHWEST WY.  THE ECMWF/GFS/UKMET/12Z GEFS MEAN SHOW SIMILAR
TIMING/AMPLITUDE OF THE MID-UPPER TROUGH SO THE SOLUTIONS WERE
EQUALLY WEIGHTED IN THE PROBABILITY FORECAST.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.

PETERSEN

$$




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