798
FXUS04 KWBC 302057
QPFPFD
QUANTITATIVE PRECIPITATION FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
457 PM EDT WED MAY 30 2018
PRELIM DAY 1, DAY 2 AND DAY 3 QPF DISCUSSION
VALID MAY 31/0000 UTC THRU JUN 03/0000 UTC
REFERENCE AWIPS GRAPHICS UNDER...PRECIP ACCUM - 24HR
DAY 1
..UPPER GREAT LAKES AND MIDWEST
ALBERTO IS EXPECTED TO CONTINUE TRACKING PROGRESSIVELY TO THE
NORTH, PRODUCING LOCALLY HEAVY AMOUNTS NEAR THE CENTER AS IT
TRACKS FROM INDIANA ACROSS LOWER MICHIGAN THIS EVENING OVERNIGHT,
WITH ADDITIONAL MODERATE TO LOCALLY HEAVY AMOUNTS CONTINUING TO
DEVELOP FURTHER WEST ACROSS WISCONSIN AND MINNESOTA AS MOISTURE
STREAMING OUT AHEAD OF THE CENTER INTERACTS WITH AN APPROACHING
NEGATIVELY-TILTED UPPER TROUGH. WPC QPF REFLECTS CONSENSUS OF THE
12Z HI-RES MODELS, WHICH CONTINUED TO MAINTAIN A GOOD SIGNAL FOR
1-2 INCH AMOUNTS, WITH LOCALLY HEAVIER AMOUNTS FROM NORTHERN
INDIANA INTO WESTERN LOWER MICHIGAN THIS AFTERNOON AND EVENING.
..CENTRAL PLAINS TO THE LOWER OHIO AND TENNESSEE VALLEYS
WHILE SHOWING SOME DIFFERENCES IN THE DETAILS, THE 12Z HI-RES
MODELS RUNS CONTINUE TO SHOW A GOOD SIGNAL FOR DEVELOPING MODERATE
TO HEAVY RAINS THIS EVENING-OVERNIGHT AS A SHORTWAVE TROUGH MOVING
OUT OF THE CENTRAL ROCKIES INTERACTS WITH MOISTURE POOLING ALONG A
STATIONARY BOUNDARY EXTENDING ALONG THE KANSAS-OKLAHOMA BORDER.
CONVECTION IS EXPECTED TO WANE THU MORNING AS THE LEAD SHORTWAVE
MOVES ACROSS THE MID MISSISSIPPI VALLEY BEFORE REDEVELOPING
FURTHER DOWNSTREAM ACROSS THE LOWER OHIO AND TENNESSEE VALLEYS,
WITH UPSTREAM ENERGY POSSIBLY SPURRING SOME ADDITIONAL
REDEVELOPMENT ACROSS THE MID MISSISSIPPI VALLEY LATER IN THE DAY
AS WELL. WPC QPF GAVE SIGNIFICANT WEIGHTING TO THE HREF MEAN
THROUGH MOST OF THE PERIOD.
...LOWER GREAT LAKES / UPPER OHIO VALLEY / CENTRAL APPALACHIANS /
MID ATLANTIC...
AS THE AFOREMENTIONED TROUGH OVER THE UPPER MIDWEST TRANSLATES
EASTWARD THIS PERIOD, A NORTHWEST-SOUTHEAST ORIENTED BOUNDARY AND
THE LEADING EDGE OF A VERY MOIST AIRMASS EXTENDING FROM THE
MID-ATLANTIC FROM THE GREAT LAKES IS EXPECTED TO MOVE NORTH THIS
PERIOD. GUIDANCE SHOWS DEEP MOISTURE SURGING NORTH ALONG THE
CENTRAL APPALACHIANS AND MID-ATLANTIC AS THE LOW LEVEL FLOW BACKS
AHEAD OF THE APPROACHING TROUGH. THIS MOISTURE ALONG WITH
AFTERNOON HEATING AND THE LARGER SCALE FORCING AFFORDED BY THE
APPROACHING TROUGH IS EXPECTED TO SUPPORT AND INCREASING THREAT
FOR MODERATE TO LOCALLY HEAVY AMOUNTS BOTH ALONG THE HIGHER
TERRAIN AND AHEAD OF A COLD FRONT PUSHING ACROSS THE LOWER GREAT
LAKES LATE FRI. WPC QPF GAVE SIGNIFICANT WEIGHTING TO THE HREF
MEAN THROUGH MOST OF THE PERIOD.
...NORTHERN INTERMOUNTAIN WEST / NORTHERN ROCKIES AND HIGH
PLAINS...
AS AN UPPER LEVEL TROUGH CONTINUES TO AMPLIFY ACROSS THE
NORTHWEST, A DEVELOPING UPPER JET COUPLET ALONG WITH AMPLE
MOISTURE ALONG THE LOW TO MID LEVEL BOUNDARY THERE REMAINS A GOOD
SIGNAL FOR WIDESPREAD LIGHT TO LOCALLY HEAVIER AMOUNTS ACROSS THE
REGION. WPC QPF REFLECTS A CONSENSUS OF THE HI-RES MODELS HERE AS
WELL.
DAYS 2/3...
..NORTHERN ROCKIES INTO NORTHERN PLAINS
A BAROCLINIC ZONE EXTENDING FROM NORTHERN HIGH PLAINS TO GREAT
BASIN WILL MOVE EASTWARD TO THE UPPER/MIDDLE MISSISSIPPI VALLEY
INTO THE SOUTHERN PLAINS BY SATURDAY EVENING. AS THE SYSTEM MOVES
OUT OF THE ROCKIES INTO A PLUME OF MOISTURE WITH PRECIPITABLE
WATER VALUES OF 1.25 TO 1.00 INCHES OVER THE NORTHERN PLAINS ON
THURSDAY EVENING INTO FRIDAY EVENING PRODUCING CONVECTION OVER THE
NORTHERN PLAINS WITH MAXIMUM QPF AMOUNTS RANGING FROM 1.50 TO 2.00
INCHES. A SECONDARY MAXIMUM WILL DEVELOP UNDER THE ASSOCIATED
UPPER-LEVEL LOW WITH MAXIMUM QPF AMOUNTS RANGING FROM 1.20 TO 1.00
INCHES. OVERNIGHT FRIDAY, MOISTURE WILL SURGE INTO THE PLAINS
WITH PRECIPITABLE WATER VALUES OF 1.50 INCHES AND THE MOISTURE
INCREASING AGAIN OVER THE MIDDLE MISSISSIPPI VALLEY WITH
PRECIPITABLE WATER VALUES OF 1.75 INCHES BY SATURDAY EVENING. THE
SYSTEM WILL PRODUCE MAXIMUM QPF OVER THE CENTRAL PLAINS WITH QPF
AMOUNTS RANGING FROM 2.20 TO 2.00 INCHES ON FRIDAY EVENING INTO
SATURDAY EVENING. A SECONDARY MAXIMUM WILL ALSO DEVELOP OVER
PARTS OF THE NORTHERN PLAINS WITH MAXIMUM QPF AMOUNTS RANGING FROM
1.75 TO 2.00 INCHES. THE HIGH QPF AMOUNTS ON THURSDAY EVENING
INTO FRIDAY EVENING AND FRIDAY EVENING INTO SATURDAY EVENING
PROMPTED THE PLACEMENT OF A SLIGHT RISK OF EXCESSIVE RAINFALL OVER
THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS AND OVER PARTS OF
THE NORTHERN/CENTRAL PLAINS.
..OZARKS INTO THE NORTHEAST AND THE MID-ATLANTIC
ANOTHER BAROCLINIC ZONE EXTENDING FROM THE GREAT LAKES INTO THE
CENTRAL PLAINS WILL MOVE OFF THE NORTHEAST/NORTHERN MID-ATLANTIC
COAST EXTENDING WESTWARD TO THE MIDDLE MISSISSIPPI VALLEY BY
SATURDAY EVENING. MOISTURE WILL POOL ALONG THE BOUNDARY WITH
PRECIPITABLE WATER VALUES RANGING FROM 1.75 TO 1.50 INCHES THROUGH
SATURDAY EVENING. THE SYSTEM WILL PRODUCE MAXIMUM QPF AMOUNTS
RANGING FROM 1.25 TO 0.75 INCHES OVER THE SOUTHERN OHIO/TENNESSEE
VALLEYS ON THURSDAY EVENING INTO FRIDAY EVENING WITH A SECONDARY
MAXIMUM OVER THE OZARKS WITH MAXIMUM QPF AMOUNTS RANGING FROM 1.00
TO 0.75 INCHES. AS THE SYSTEM MOVES EAST THE MAXIMUM QPF AMOUNTS
WILL RANGE FROM 0.75 TO 0.50 INCHES OVER THE MID-ATLANTIC ON
FRIDAY EVENING INTO SATURDAY EVENING.
..FLORIDA
SHORT WAVE MOVING OVER THE FLORIDA PANHANDLE WILL MOVE INTO
MOISTURE WITH PRECIPITABLE WATER VALUES RANGING FROM 1.7R TO 2.00
INCHES. THE ENERGY WILL PRODUCE CONVECTION OVER THE CENTRAL
PORTION OF THE PENINSULA PRODUCING MAXIMUM QPF AMOUNTS RANGING
FROM 1.00 TO 1.20 INCHES ON THURSDAY EVENING INT FRIDAY EVENING.
PEREIRA/ZIEGENFELDER
GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV/QPF/QPF2.SHTML
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