Quantitative Precipitation Forecast
Issued by NWS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13

000
FOUS11 KWBC 160957
QPFHSD

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
457 AM EST MON JAN 16 2017

VALID 12Z MON JAN 16 2017 - 12Z THU JAN 19 2017

CENTRAL PLAINS/UPPER MIDWEST...

THE SREF AND GEFS MEMBERS ARE MOST CLUSTERED AROUND THE
DETERMINISTIC FORECAST FOR UPWARDS OF 4 INCHES OF SNOW ACROSS
NORTHWEST KANSAS TODAY...WITH THE ECMWF ENSEMBLES DEPICTING THE
HIGHEST PROBABILITIES ACROSS SOUTHWEST KANSAS. WITH THE MODELS
TRENDING NORTH AND/OR NORTHWESTWARD WITH THE PIVOTING UPPER
LOW...THE EMPHASIS ACROSS NORTHWEST KANSAS IS MORE PREFERRED. THE
SAME APPLIES WITH THE ICE PROBABILITIES...WITH LOW AND MODERATE
CHANCES OF 0.25 INCHES OF ICE EXTENDING FROM EASTERN NEBRASKA TO
SOUTHERN WISCONSIN THROUGH TONIGHT...
BEST SUPPORTED BY THE SREF AND GEFS MEMBERS MORE THAN THE ECMWF
ENSEMBLE MEMBERS.

NORTHEAST/NEW ENGLAND...

LOW CHANCES OF 0.25 INCHES OF ICE ALONG WITH MODERATE CHANCES OF 4
INCHES OF SNOW AND LOW CHANCES OF 8 INCHES OF SNOW EXTEND ACROSS
PORTIONS OF EASTERN NEW YORK INTO VERMONT/NEW HAMPSHIRE
RESPECTIVELY FOR TUESDAY AND TUESDAY NIGHT. THE MODEL SPREAD
REMAINS CONSIDERABLE FOR A DAY 2 FORECAST...WITH THE SREF AND GEFS
MEMBERS GENERALLY CLUSTERED AROUND THE DETERMINISTIC VALUES OF ICE
AND SNOW...WITH THE ECMWF ENSEMBLE MEMBERS TOWARD THE SOUTHWEST
SIDE OF THE GUIDANCE ENVELOPE. WITH MOST 18-00Z GUIDANCE TRENDING
FASTER WITH THE SURFACE LOW...THE ECMWF ENSEMBLE MEMBERS MAY BE
TOO FAR SOUTHWEST COMPARED WITH OTHER GUIDANCE. THE LARGER-SCALE
MODEL SPREAD THAT SUGGESTS ABOVE AVERAGE UNCERTAINTY WITH THE PATH
OF THE LOW AND ACCOMPANYING CHANGES IN THERMAL PROFILES AND
THEREFORE P-TYPE SUPPORT LOW CONFIDENCE WITH THIS FORECAST.

NORTHWEST/CALIFORNIA...

RELIANCE UPON STRONG ONSHORE FLOW AND RESULTING OROGRAPHIC ASCENT
COMBINED WITH HIGH STATIC STABILITY IN THE INTERIOR FAVOR HIGH
CHANCES OF ICE...POSSIBLY WITH SIGNIFICANT TOTALS...FOR AREAS EAST
OF THE WASHINGTON CASCADES BEGINNING TONIGHT AND LIKELY PEAKING
TUESDAY AND TUESDAY NIGHT BEFORE WANING AS THE FLOW BEGINS BACKS
TO A MORE SOUTHERLY DIRECTION AND TEMPERATURES EVENTUALLY RISE
ABOVE FREEZING. MODEL CONVERGENCE IS QUITE HIGH WITH THE ICE
CHANCES...WITH THE FOOTHILLS EAST OF THE CASCADES/PORTIONS OF THE
COLUMBIA RIVER GORGE/FOOTHILLS OF THE BITTERROOTS MOST LIKELY TO
RECEIVE CONSIDERABLE AMOUNTS DUE IN LARGE PART TO THE QUANTITY AND
DURATION OF THE ATMOSPHERIC RIVER EVENT. FORECAST SOUNDINGS
SUPPORT EITHER A MIX OR TRANSITION TO SLEET OR SNOW AT THE LOWEST
ELEVATIONS WHERE COLD AIR WILL BE DEEPEST. THE FINAL PROBABILITIES
SHOW MODERATE TO HIGH CHANCES OF 0.25 INCHES OR MORE OF ICE FOR
THE ABOVE MENTIONED AREAS. LIKEWISE...MODERATE TO HIGH CHANCES OF
8 TO 12 INCHES OF SNOW WILL FORM AT MOST ELEVATIONS ABOVE 4
THOUSAND FEET FOR THE
CASCADES/BITTERROOTS/SISKIYOUS/SIERRAS...WITH ALL THE ENSEMBLE
SYSTEMS WELL CLUSTERED THROUGH WEDNESDAY NIGHT. REFER TO THE LOCAL
WEATHER FORECAST OFFICES FOR ADDITIONAL
STATEMENTS/WATCHES/WARNINGS.

JAMES

$$





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