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000
FXSA20 KWBC 291340
PMDSA

SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
939 AM EDT FRI APR 29 2016

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

SYNOPSIS (VALID FROM APR 29 AT 0000 UTC): UNDER PRESSURE FROM A
HIGH AMPLITUDE POLAR TROUGH TO THE SOUTH...THE SUBTROPICAL RIDGE
AT 200 HPA NOW CONFINES TO EQUATORIAL SOUTH AMERICA. ORGANIZED
CONVECTION IS CLUSTERING ALONG THE NEAR EQUATORIAL TROUGH OVER
COLOMBIA-VENEZUELA AND THE GUIANAS.

THE 250 HPA JET ANALYSIS SHOWS THE SOUTHERN POLAR JET ALONG A
155KT MAXIMA AT 59S 119W...A 155KT MAXIMA AT 67S 96W...71S 79W...A
158KT MAXIMA AT 69S 65W...63S 58W...EXITING AT 56S 49W. ANOTHER
BRANCH FORMS AT 42S 61W...EXITING AT 40S 45W. THE NORTHERN POLAR
JET FORMS AT 49S 109W ALONG 41S 113W...EXITING AT 34S 108W. IT
REFORMS AT 34S 104W ALONG 40S 91W...41S 75W...EXITING AT 36S 64W.
IT REFORMS AT 31S 43W ALONG A 133KT MAXIMA AT 34S 36W...A 153KT
MAXIMA AT 42S 26W. THE SUBTROPICAL JET FORMS AT 23S 108W ALONG A
138KT MAXIMA AT 32S 98W...A 146KT MAXIMA AT 37S 88W...A 144KT
MAXIMA AT 38S 78W...A 156KT MAXIMA AT 35S 69W...EXITING AT 23S
54W. A WEAKER BRANCH OF THE SUBTROPICAL JET FORMS AT 21S 104W
ALONG 29S 94W...34S 76W...EXITING AT 23S 64W.

AT 500 HPA...BROAD TROUGH DOMINATES THE NORTHERN STREAM FLOW OVER
THE EASTERN PACIFIC...WITH AXIS ENVELOPING AREA BETWEEN 120W-85W
WHILE ANCHORING ON A CLOSED LOW AT 44S 107W. A SKEWED RIDGE LIES
TO THE EAST...WITH AXIS SOUTH FROM A HIGH AT 21S 80W...ALONG 45S
78W...A HIGH AT 53S 79W...TO 55S 95W. EAST OF THIS AXIS...A HIGH
AMPLITUDE TROUGH EXTENDS ACROSS THE WESTERN ATLANTIC TO
PARAGUAY/BOLIVIA-CENTRAL BRASIL. THE UNUSUALLY STRONG TROUGH IS
PROVIDING DYNAMICAL SUPPORT TO ORGANIZED CONVECTION ACROSS
TOCANTINS-PARA IN BRASIL.

THE SURFACE ANALYSIS SHOWS TWO 1029 HPA POLAR HIGHS IN THE
SOUTHERN CONE. ONE CENTERS AT 55S 81W...AND RIDGES ACROSS PUNTA
ARENAS INTO THE OTHER HIGH NEAR COMODORO RIVADAVIA AT 45S 69W. TO
THE EAST...A 1008 HPA OCCLUDED LOW CENTERS AT 42S 54W EXTENDING A
FRONT ALONG A 1004 HPA LOW AT 45S 52W...40S 50W...37S 57W...39S
66W. A 1025 HPA HIGH CENTERS AT 28S 51W AND RIDGES ALONG
PARAGUAY-BOLIVIA/ACRE/PERU INTO A 1019 HPA HIGH AT 04S 72W. A 1012
HPA LOW AT 36S 24W EXTENDS A FRONT ALONG 20S 31W...A 1016 HPA LOW
AT 23S 40W...19S 42W...A 1014 HPA LOW AT 17S 45W...12S 51W...08S
59W...04S 65W...02S 70W...ECUADOR/COLOMBIA BORDER. A SHEAR LINE
EXTENDS ALONG 18S 41W ALONG 10S 47W...04S 55W...02N 64W...SOUTHERN
VENEZUELA. STRONG CONVECTION WAS OCCURRING ALONG THE SHEAR LINE.

AYALA...DINAC (PARAGUAY)
ENRIQUEZ...DGAC (ECUADOR)
DAVISON/GALVEZ...WPC (USA)
$$







000
FXCA20 KWBC 291042
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
642 AM EDT FRI APR 29 2016

PRELIMINARY DISCUSSION FOR PUERTO RICO AND THE USVI FROM APRIL
29/06 UTC: A PROGRESSIVE SHORT WAVE TROUGH TAKES A BEELINE ACROSS
THE FORECAST AREA DURING THE DAY TODAY...WITH ANOTHER TO FOLLOW
DURING THE DAY ON SATURDAY. UNDER INFLUENCE OF THESE PERTURBATIONS
THE SUBTROPICAL JET IS TO MOVE TO THE NORTHERN CARIBBEAN...EXITING
OVER THE DOMINICAN REPUBLIC/MONA PASSAGE. THIS WILL FAVOR AN UPPER
DIVERGENT PATTERN THAT IS TO CONTINUE VENTING DEEP CONVECTION
ACROSS THE NORTHEAST CARIBBEAN ISLES. THE UNSETTLED AND HIGHLY
UNSTABLE AIR MASS IS FORECAST TO PERSIST THROUGH SUNDAY
EVENING...WITH A POSSIBLE LULL IN ACTIVITY ON MONDAY AHEAD OF THE
NEXT MID/UPPER LEVEL PERTURBATION. A MOIST SOUTHEASTERLY FLOW IS
TO DOMINATE BELOW 800 HPA...TO ENHANCE MOISTURE
TRANSPORT/CONVERGENCE ACROSS THE FORECAST AREA. PWAT OVER THE NEXT
FEW DAYS IS TO RANGE BETWEEN 40-50MM...WITH HIGHER VALUES LIKELY
EARLY NEXT WEEK AS A DEEPER MID/UPPER LEVEL TROUGH AMPLIFIES
ACROSS THE BASIN. THIS IS TO CONTINUE FUELING CONVECTIVE
DEVELOPMENT ACROSS PUERTO RICO-VIRGIN ISLES THROUGHOUT THE MEDIUM
RANGE PERIOD.

ALTHOUGH MODELS DISAGREE ON WHERE THE MOST INTENSE CONVECTION IS
TO DEVELOP...THEY GENERALLY AGREE ON ENVIRONMENTAL CONDITIONS TO
REMAIN FAVORABLE AND CONDUCIVE TO ORGANIZED CONVECTION TO DEVELOP.
GENERAL TREND REMAINS AS PREVIOUSLY NOTED...WITH MODELS SHOWING
CONVECTION BECOMING MORE INTENSE AND WIDESPREAD DURING THE WEEKEND
AS A STRONGER MID/UPPER LEVEL PERTURBATION STREAMS ACROSS THE
FORECAST AREA. A SECOND ROUND OF HEAVY CONVECTION IS POSSIBLE ON
TUESDAY AND ONWARD AS AN EVEN STRONGER/DEEPER TROUGH MOVES ACROSS
THE CARIBBEAN. DAILY RAINFALL AMOUNTS ARE EXPECTED TO RANGE
BETWEEN 1-2 INCHES...WITH LOCALIZED MAXIMA OF 3-5 INCHES. MOST
INTENSE IS TO CLUSTER OVER PUERTO RICO JUST NORTH OF THE
CORDILLERA...WITH A SECONDARY MAXIMA LIKELY ACROSS
CAROLINA-CAGUAS-SAN JUAN METRO AREA AS ENHANCED BY A 700 HPA
SOUTHWESTERLY STEERING FLOW. ACROSS THE VIRGIN ISLES THE THREAT OF
HEAVY RAINS IS NOT AS HIGH TODAY...BUT ON SATURDAY THIS IS LIKELY
TO INCREASE AS MID/UPPER LEVEL PATTERN EVOLVES.

CARDOS...SMN (MEXICO)
CABANERIT...INAMEH (VENEZUELA)
DAVISON/GALVEZ...WPC (USA)
$$







000
FXUS01 KWBC 290839
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
438 AM EDT FRI APR 29 2016

VALID 12Z FRI APR 29 2016 - 12Z SUN MAY 01 2016

...THERE ARE SLIGHT RISKS OF SEVERE THUNDERSTORMS OVER PARTS OF
THE SOUTHERN PLAINS INTO PARTS OF THE LOWER MISSISSIPPI VALLEY...

...HEAVY RAIN POSSIBLE OVER PARTS OF THE LOWER MISSISSIPPI
VALLEY/WESTERN TENNESSEE VALLEY INTO PARTS OF EASTERN TEXAS...

...HEAVY RAIN POSSIBLE OVER PARTS OF THE CENTRAL PLAINS...

...SNOW OVER PARTS OF THE CENTRAL ROCKIES AND CENTRAL HIGH
PLAINS...

A STORM OVER TEXAS WILL SLOWLY MOVE NORTHEASTWARD TO CENTRAL
PLAINS/MIDDLE MISSISSIPPI VALLEY BY SATURDAY EVENING.  SHOWERS AND
THUNDERSTORMS WILL DEVELOP OVER THE SOUTHERN PLAINS THAT WILL MOVE
EASTWARD TO THE LOWER MISSISSIPPI VALLEY AND NORTHEASTWARD INTO
THE OHIO/TENNESSEE VALLEYS AND PARTS OF THE CENTRAL/SOUTHERN
APPALACHIANS BY SATURDAY EVENING.  IN ADDITION, RAIN WILL DEVELOP
OVER PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS THROUGH SATURDAY.
SNOW WILL DEVELOP OVER PARTS OF THE CENTRAL ROCKIES/HIGH PLAINS
ALSO THROUGH SATURDAY.

MEANWHILE, UPPER-LEVEL ENERGY OVER THE GREAT LAKES WILL MOVE
EASTWARD OFF THE NORTHERN MID-ATLANTIC COAST BY SATURDAY MORNING.
THE ENERGY WILL PRODUCE RAIN OVER PARTS OF THE GREAT LAKES TO THE
NORTHERN MID-ATLANTIC THAT WILL MOVE INTO PARTS OF SOUTHERN NEW
ENGLAND BY EARLY SATURDAY MORNING BEFORE ENDING.  ADDITIONALLY, A
THIRD SYSTEM OVER THE PACIFIC NORTHWEST WILL MOVE SOUTHWARD TO
SOUTHERN CALIFORNIA/NORTHERN MEXICO BY SATURDAY.  THE STORM WILL
DEVELOP RAIN OVER PARTS OF THE NORTHWEST AND RAIN AND HIGHEST
ELEVATION SNOW OVER PARTS OF THE NORTHERN INTERMOUNTAIN REGION AND
THE NORTHERN ROCKIES.  AS THE SYSTEM MOVE SOUTH, RAIN WITH
EMBEDDED THUNDERSTORMS WILL DEVELOP OVER PARTS OF THE GREAT BASIN
WITH RAIN EXTENDING AS FAR SOUTH AS CENTRAL CALIFORNIA AND PARTS
OF THE SOUTHWEST BY FRIDAY EVENING.  THE RAIN WILL BE RESTRICTED
TO PARTS OF THE GREAT BASIN BY SATURDAY MORNING, EXPANDING INTO
PARTS OF THE SOUTHWEST/SOUTHERN ROCKIES WITH RAIN WITH EMBEDDED
THUNDERSTORMS BY SATURDAY EVENING.  SIMILARLY, RAIN WILL DEVELOP
OVER PARTS OF THE NORTHERN/CENTRAL ROCKIES BY SATURDAY EVENING,
TOO.


ZIEGENFELDER


GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$







000
FXUS01 KWBC 290759
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
358 AM EDT FRI APR 29 2016

VALID 12Z FRI APR 29 2016 - 12Z SUN MAY 01 2016

...THERE ARE SLIGHT RISKS OF SEVERE THUNDERSTORMS OVER PARTS OF
THE SOUTHERN PLAINS INTO PARTS OF THE LOWER MISSISSIPPI VALLEY...

...HEAVY RAIN POSSIBLE OVER PARTS OF THE LOWER MISSISSIPPI
VALLEY/WESTERN TENNESSEE VALLEY INTO PARTS OF EASTER TEXAS...

...HEAVY RAIN POSSIBLE OVER PARTS OF THE CENTRAL PLAINS...

...SNOW OVER PARTS OF THE CENTRAL ROCKIES AND CENTRAL HIGH
PLAINS...

A STORM OVER TEXAS WILL SLOWLY MOVE NORTHEASTWARD TO CENTRAL
PLAINS/MIDDLE MISSISSIPPI VALLEY BY SATURDAY EVENING.  SHOWERS AND
THUNDERSTORMS WILL DEVELOP OVER THE SOUTHERN PLAINS THAT WILL MOVE
EASTWARD TO THE LOWER MISSISSIPPI VALLEY AND NORTHEASTWARD INTO
THE OHIO/TENNESSEE VALLEYS AND PARTS OF THE CENTRAL/SOUTHERN
APPALACHIANS BY SATURDAY EVENING.  IN ADDITION, RAIN WILL DEVELOP
OVER PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS THROUGH SATURDAY.
SNOW WILL DEVELOP OVER PARTS OF THE CENTRAL ROCKIES/HIGH PLAINS
ALSO THROUGH SATURDAY.


ZIEGENFELDER


GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$







000
FXUS02 KWBC 290554
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
153 AM EDT FRI APR 29 2016

VALID 12Z MON MAY 02 2016 - 12Z FRI MAY 06 2016

...GUIDANCE ASSESSMENT AND WEATHER HIGHLIGHTS/THREATS...

LEAD MID-UPPER LEVEL TROUGH ENERGIES SHEAR OVER THE ERN US MON TO
SUPPORT A LINGERING RAINFALL SWATH ASSOCIATED WITH EXITING LOWS
AND THEIR TRAILING FRONT. MEANWHILE...MID-UPPER LEVEL TROUGH
ENERGIES OVER THE SWRN US/S-CENTRAL ROCKIES SHOULD PRODUCE COOLED
PCPN WITH SOME ENHANCED SNOWS OVER FAVORED ELEVATED TERRAIN. THIS
ENERGY IS SLATED TO EJECT OUT ACROSS THE SRN/SERN US EARLY-MID
NEXT WEEK THEN POSSIBLY UP THE EAST COAST LATE WEEK TO REFOCUS
PCPN/WAVES ALONG/WELL OVERTOP THE LEAD DRAPED FRONT. THIS OCCURS
IN CONJUCTURE WITH NRN STREAM FLOW AMPLIFICATION ALOFT NEXT WEEK
OVERTOP WITH EXPECTED EVENTUAL DEVELOPMENT OF A COOLING/UNSETTLING
E-CENTRAL NOAM TROUGH AS IMPULSES DIG TO THE LEE OF A BUILDING
W-CENTRAL NOAM RIDGE. MEANWHILE UPSTREAM...POTENT ERN PACIFIC
SYSTEMS APPROACH TO THE WEST COAST IN RE-EMERGING SPLIT FLOW
SHOULD PROVE GRADUAL NEXT WEEK GIVEN OVERALL FLOW
AMPLIFICATION...BUT SHOULD EVENTUALLY USHER INLAND WIDESPREAD AND
COOLING WET FLOW LATER WEEK WITH A POSSIBLE EMPHASIS INTO CA AND
THE SOUTHWEST.

OVERALL...THE WPC MEDIUM RANGE PRODUCT SUITE WAS PRIMARILY DERIVED
FROM A COMPOSITE BLEND OF THE 18 UTC GEFS MEAN AND THE 12 UTC
NAEFS/ECMWF ENSEMBLE MEANS ALONG WITH CONTINUITY. THESE ENSEMBLE
SYSTEMS ARE NOT AS COMPATABLE AS NORMALLY PREFERRED...BUT
CERTAINLY OFFER BETTER CONTINUITY THAN RECENT RUN TO RUN TRENDS OF
THE DETERMINITSIC MODELS IN SENSITIVE PATTERN WITH UNCERTAIN FLOW
DETAILS/INTERACTIONS.

SCHICHTEL



$$







000
FXUS01 KWBC 282004
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
403 PM EDT THU APR 28 2016

VALID 00Z FRI APR 29 2016 - 00Z SUN MAY 01 2016

...THERE ARE SLIGHT RISKS OF SEVERE THUNDERSTORMS OVER PARTS OF
THE SOUTHERN PLAINS AND OVER PARTS OF THE SOUTHERN MID-ATLANTIC...

...HEAVY RAIN POSSIBLE OVER PARTS OF THE SOUTHERN PLAINS,
LOWER/MIDDLE MISSISSIPPI VALLEY AND WESTERN TENNESSEE VALLEY...

...SNOW OVER PARTS OF THE CENTRAL ROCKIES...

SHOWERS AND THUNDERSTORMS ARE GENERATING ALONG AND AHEAD OF A LOW
PRESSURE SYSTEM MOVING THROUGH THE MISSISSIPPI, OHIO AND TENNESSEE
VALLEYS THIS AFTERNOON. SOME OF THE STORMS TRACKING THROUGH THE
MID-ATLANTIC REGION COULD POTENTIALLY TURN SEVERE. THE STORM
PREDICTION CENTER HAS ISSUED A SLIGHT RISK FOR PORTIONS OF WEST
VIRGINIA, VIRGINIA AND NORTH CAROLINA. SEVERAL STORMS HAS
DEVELOPED ALONG THE CENTRAL GULF COAST AND ACROSS THE SOUTHEAST;
HOWEVER THE THREAT FOR TURNING SEVERE IS MARGINAL. THE SYSTEM WILL
CONTINUE TO ADVANCE EASTWARD THROUGH FRIDAY AFTERNOON. SCATTERED
SHOWERS AND THUNDERSTORMS CONTINUE ALONG THE APPALACHIANS THROUGH
FRIDAY EVENING WITH MOST COASTAL AREAS HAVING CLEARED OUT.

HEAVY RAIN AND FLASH FLOODING IS ALSO A CONCERN WITH SOME OF THE
STORMS THAT ARE TRACKING THROUGH THE MID-ATLANTIC. EXCESSIVE
RAINFALL OUTLOOKS HAVE BEEN ISSUED FOR PORTIONS OF EASTERN
KENTUCKY, MOST OF WEST VIRGINIA AND NORTHEAST NORTH CAROLINA. THE
THREAT IS EXPECTED TO WEAKEN OR DIMINISH BY EARLY FRIDAY MORNING.

A SECOND STORM WILL PUSH THROUGH THE FOUR CORNERS REGION THIS
EVENING AND CROSS THE SOUTHERN ROCKIES ON FRIDAY. SCATTERED
SHOWERS AND A FEW THUNDERSTORMS HAVE DEVELOPED OVER THE DESERT
SOUTHWEST, GREAT BASIN AND PORTIONS OF THE SOUTHERN/CENTRAL
ROCKIES TODAY. RAIN AND HIGHER ELEVATION SNOW ACROSS PORTIONS OF
THE WEST AND GREAT PLAINS WILL CONTINUE INTO THE WEEKEND. SNOW
ACCUMULATIONS OF 1 TO 2 FEET MAY BE POSSIBLE FOR THE HIGHEST
ELEVATIONS OF THE COLORADO ROCKIES BY SUNDAY EVENING.
SNOW WILL DECREASE INTENSITY THROUGH THE DAY ON SATURDAY AS THE
SYSTEM PUSHES FURTHER INTO THE SOUTHERN PLAINS.

STRONG TO SEVERE THUNDERSTORMS WILL LIKELY DEVELOP ACROSS PORTIONS
OF OKLAHOMA, TEXAS, WESTERN ARKANSAS AND NORTHERN LOUISIANA ON
FRIDAY. THE STORM PREDICTION CENTER HAS ISSUED A SLIGHT RISK FOR
PORTIONS OF THE SOUTHERN PLAINS THROUGH EARLY SATURDAY MORNING.
HEAVY RAINFALL WILL LIKELY ACCOMPANY THE CONVECTION ON FRIDAY AND
SATURDAY THEREFORE AN EXCESSIVE RAINFALL OUTLOOK HAS BEEN ISSUED
FOR NEARLY THE SAME REGION. THE AREA OF INCREASED RISK WILL SHIFT
TO THE EAST ON SATURDAY, SPANNING FROM THE WESTERN GULF COAST TO
THE MIDDLE MISSISSIPPI VALLEY.

IN ADDITION BY FRIDAY MORNING, A THIRD SYSTEM WILL MOVE ONSHORE
OVER PACIFIC NORTHWEST MOVING TO PARTS OF THE GREAT BASIN/CENTRAL
CALIFORNIA BY FRIDAY EVENING.  RAIN WILL BEGIN OVER PARTS OF THE
PACIFIC NORTHWEST ON FRIDAY MORNING THAT WILL EXTEND FROM THE
NORTHWEST TO PARTS OF THE ROCKIES AND THE SOUTHWEST BY FRIDAY
EVENING.

CAMPBELL


GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$







000
FXUS01 KWBC 282000
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
359 PM EDT THU APR 28 2016

VALID 00Z FRI APR 29 2016 - 00Z SUN MAY 01 2016

...THERE ARE SLIGHT RISKS OF SEVERE THUNDERSTORMS OVER PARTS OF
THE SOUTHERN PLAINS AND OVER PARTS OF THE SOUTHERN MID-ATLANTIC...

...HEAVY RAIN POSSIBLE OVER PARTS OF THE SOUTHERN PLAINS,
LOWER/MIDDLE MISSISSIPPI VALLEY AND WESTERN TENNESSEE VALLEY...

...SNOW OVER PARTS OF THE CENTRAL ROCKIES...

SHOWERS AND THUNDERSTORMS ARE GENERATING ALONG AND AHEAD OF A LOW
PRESSURE SYSTEM MOVING THROUGH THE MISSISSIPPI, OHIO AND TENNESSEE
VALLEYS THIS AFTERNOON. SOME OF THE STORMS TRACKING THROUGH THE
MID-ATLANTIC REGION COULD POTENTIALLY TURN SEVERE. THE STORM
PREDICTION CENTER HAS ISSUED A SLIGHT RISK FOR PORTIONS OF WEST
VIRGINIA, VIRGINIA AND NORH CAROLINA. SEVERAL SOTRMS HAS DEVELOPED
ALONG THE CENTRAL GULF COAST AND ACROSS THE SOUTHEAST; HOWEVER THE
THREAT FOR TURNING SEVERE IS MARGINAL. THE SYSTEM WILL CONTINUE TO
ADVANCE EASTWARD THROUGH FRIDAY AFTERNOON. SCATTERED SHOWERS AND
THUNDERSTORMS CONTINUE ALONG THE APPLACHIANS THROUGH FRIDAY
EVENING WITH MOST COASTAL AREAS HAVING CLEARED OUT.

HEAVY RAIN AND FLASH FLOODING IS ALSO A CONCERN WITH SOME OF THE
STORMS THAT ARE TRACKING THROUGH THE MID-ATLANTIC. EXCESSIVE
RAINFALL OUTLOOKS HAVE BEEN ISSUED FOR PORTIONS OF EASTERN
KENTUCKY, MOST OF WEST VIRGINIA AND NORTHEAST NORTH CAROLINA. THE
THREAT IS EXPECTED TO WEAKEN OR DIMINISH BY EARLY FRIDAY MORNING.

A SECOND STORM WILL PUSH THROUGH THE FOUR CORNERS REGION THIS
EVENING AND CROSS THE SOUTHERN ROCKIES ON FRIDAY. SCATTERED
SHOWERS AND A FEW THUNDERSTORMS HAVE DEVELOPED OVER THE DESERT
SOUTHWEST, GREAT BASIN AND PORTIONS OF THE SOUTHERN/CENTRAL
ROCKIES TODAY. RAIN AND HIGHER ELEVATION SNOW ACROSS PORTIONS OF
THE WEST AND GREAT PLAINS WILL CONTINUE INTO THE WEEKEND. SNOW
ACCUMULATIONS OF 1 TO 2 FEET MAY BE POSSIBLE FOR THE HIGHEST
ELEVATIONS OF THE COLORADO ROCKIES BY SUNDAY EVENING.
SNOW WILL DECREASE INTENSITY THROUGH THE DAY ON SATURDAY AS THE
SYSTEM PUSHES FURTHER INTO THE SOUTHERN PLAINS.

STRONG TO SEVERE THUNDERSTORMS WILL LIKELY DEVELOP ACROSS PORTIONS
OF OKLAHOMA, TEXAS, WESTERN ARKANSAS AND NORT. THE STORM
PREDICTION CENTER HAS ISSUED A SLIGHT RISK FOR PORTIONS OF THE
SOUTHERN PLAINS THROUGH EARLY SATURDAY MORNING. HEAVY RAINFALL MAY
ALSO ACCOMPANY THE CONVECTION OF FRIDAY, THEREFORE AN EXCESSIVE
RAINFALL OUTLOOK HAS BEEN ISSUED FOR NEARLY THE SAME REGION.

ON FRIDAY AFTERNOON INTO EVENING, SHOWERS AND THUNDERSTORMS WILL
DEVELOP OVER PARTS OF THE SOUTHERN HIGH PLAINS SOUTHEASTWARD TO
PARTS OF THE WESTERN GULF COAST.  THE SHOWERS AND THUNDERSTORMS
WILL EXPAND INTO PARTS OF THE CENTRAL HIGH/CENTRAL PLAINS AND INTO
PARTS OF THE LOWER MISSISSIPPI VALLEY OVERNIGHT THURSDAY INTO
FRIDAY MORNING.  BY FRIDAY EVENING THE SHOWERS AND THUNDERSTORMS
WILL EXPAND INTO PARTS OF THE MIDDLE MISSISSIPPI VALLEY/TENNESSEE
VALLEY.

IN ADDITION BY FRIDAY MORNING, A THIRD SYSTEM WILL MOVE ONSHORE
OVER PACIFIC NORTHWEST MOVING TO PARTS OF THE GREAT BASIN/CENTRAL
CALIFORNIA BY FRIDAY EVENING.  RAIN WILL BEGIN OVER PARTS OF THE
PACIFIC NORTHWEST ON FRIDAY MORNING THAT WILL EXTEND FROM THE
NORTHWEST TO PARTS OF THE ROCKIES AND THE SOUTHWEST BY FRIDAY
EVENING.

CAMPBELL


GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$







000
FXUS06 KWBC 281935
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU APRIL 28 2016

6-10 DAY OUTLOOK FOR MAY 04 - 08 2016

TODAY`S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA
CIRCULATION PATTERN OVER NORTH AMERICA DURING THE 6-10 DAY PERIOD. TROUGHS ARE
FORECAST OVER THE ALEUTIAN ISLANDS, NEAR THE SOUTHERN CALIFORNIA COAST, AND
OVER EASTERN NORTH AMERICA, WHILE A RIDGE IS FORECAST OVER WESTERN CANADA.
TODAY`S MODEL 500-HPA BLENDED HEIGHT CHART INDICATES ABOVE-NORMAL HEIGHTS OVER
THE NORTHWEST CONUS AND BELOW-NORMAL HEIGHTS OVER REMAINING U.S. REGIONS.

ENHANCED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ARE FORECAST OVER THE
NORTHERN CONUS FROM THE PACIFIC COAST TO THE UPPER MISSISSIPPI VALLEY, DUE TO
ABOVE-NORMAL HEIGHTS OVER THE REGION. ENHANCED PROBABILITIES OF BELOW-NORMAL
TEMPERATURES ARE INDICATED ACROSS THE SOUTHERN CONUS AND NORTHWARD INTO THE
OHIO VALLEY AND MID-ATLANTIC STATES, WHERE 500-HPA HEIGHTS ARE BELOW-NORMAL.
ANOMALOUS SOUTHERLY FLOW, AHEAD OF THE TROUGH OVER THE EAST, ENHANCES CHANCES
OF ABOVE-NORMAL TEMPERATURES ALONG THE NEW ENGLAND COAST. ANOMALOUS SOUTHERLY
CIRCULATION AHEAD OF THE TROUGH OVER THE ALEUTIAN ISLANDS ENHANCES THE
PROBABILITIES OF ABOVE-NORMAL TEMPERATURES OVER ALASKA.

ABOVE MEDIAN PRECIPITATION IS MOST LIKELY FOR MUCH OF THE WEST IN ASSOCIATION
WITH THE TROUGH PREDICTED NEAR THE PACIFIC COAST. ENHANCED PROBABILITIES OF
BELOW-MEDIAN PRECIPITATION ARE INDICATED OVER MOST OF THE U.S. EAST BEHIND THE
PREDICTED TROUGH AXIS OVER THE REGION. NEAR OR ABOVE-MEDIAN PRECIPITATION IS
FAVORED IN SOME REGIONS OF THE SOUTHEAST AND NORTHEAST AHEAD OF THE TROUGH.
ABOVE-MEDIAN PRECIPITATION IS MOST LIKELY FOR MOST OF ALASKA, WITH THE
EXCEPTION OF THE WEST COAST, AHEAD OF THE TROUGH OVER THE ALEUTIAN ISLANDS.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF
TODAY`S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 40% OF TODAY`S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON
DAY 8, AND 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE MODELS AND TOOLS.

8-14 DAY OUTLOOK FOR MAY 06 - 12 2016

TODAY`S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA
CIRCULATION PATTERN OVER NORTH AMERICA DURING THE WEEK 2 PERIOD. TROUGHS
PERSIST IN THE FORECAST OVER THE ALEUTIAN ISLANDS, NEAR THE SOUTHWEST, AND OVER
EASTERN NORTH AMERICA, WHILE A RIDGE IS FORECAST OVER WESTERN CANADA.
ABOVE-NORMAL 500-HPA HEIGHTS PERSIST INTO WEEK 2 OVER THE NORTHWEST CONUS,
WHILE BELOW-NORMAL HEIGHTS REMAIN OVER THE SOUTHWEST. BELOW-NORMAL HEIGHT
ANOMALIES OVER THE EAST HAVE DECREASED SUBSTANTIALLY IN MAGNITUDE FOR THE 8-14
DAY PERIOD.

ENHANCED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES CONTINUE ACROSS THE PACIFIC
NORTHWEST EASTWARD INTO THE NORTHERN AND CENTRAL PLAINS STATES. ABOVE-NORMAL
TEMPERATURES ARE MOST LIKELY OVER THE NORTHEAST EXTENDING TO THE ATLANTIC COAST
FROM VIRGINIA TO MAINE, WITH A WEAKENING OF ANOMALIES RELATED TO THE TROUGH
OVER THE EAST. ENHANCED PROBABILITIES OF BELOW-NORMAL TEMPERATURES CONTINUE
INTO THE 8-14 DAY PERIOD OVER THE SOUTHWEST, AND EASTWARD INTO TEXAS AND
LOUISIANA, WHILE NEAR-NORMAL TEMPERATURES ARE MOST LIKELY OVER MOST OF THE
SOUTHEAST RELATED TO THE WEAK TROUGH OVER THE REGION. ABOVE-NORMAL TEMPERATURES
CONTINUE TO BE MOST LIKELY FOR ALASKA FOR WEEK 2.

THE FORECAST PRECIPITATION PATTERN FOR WEEK 2 IS SIMILAR TO THE FORECAST FOR
THE 6-10 DAY PERIOD, WITH ABOVE-MEDIAN PRECIPITATION OVER MUCH OF THE WEST AND
BELOW-MEDIAN PRECIPITATION OVER MUCH OF THE EAST. PROBABILITIES OF BELOW-MEDIAN
PRECIPITATION HAVE DECREASED OVER NORTHERN REGIONS OF THE EAST WITH A MORE
ZONAL CIRCULATION PREDICTED FOE WEEK 2. ABOVE-MEDIAN PRECIPITATION IS PREDICTED
TO CONTINUE INTO THE 8-14 DAY PERIOD FOR MOST OF ALASKA.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 50% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 20% OF
TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOVE AVERAGE, 4 OUT OF 5, DUE
TO GOOD AGREEMENT AMONG THE MODELS AND TOOLS.

FORECASTER: CPC FORECASTER

NOTES:


AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OCCASIONALLY MANUAL
INTERVENTION IS NECESSARY TO ADDRESS QUALITY CONTROL AND CONSISTENCY ISSUES.
IN THESE CASES, FORECASTS ARE MANUALLY DRAWN BUT A FULL DISCUSSION IS NOT
ISSUED.

THE NOTATION FOR THE CATEGORICAL FORECAST INDICATED ON THE MAPS IS
THE SAME AS THAT IN THE TABLES: A-ABOVE   N-NEAR NORMAL   B-BELOW

THE TEMPERATURE MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WARMER
(ORANGE, "A"), COLDER (BLUE, "B"), OR CLOSE TO (UNSHADED, "N")
HISTORICAL AVERAGE VALUES FOR THE CALENDAR PERIOD OF THE FORECAST
(DASHES, "F").  LABELS ON THE SHADED LINES GIVE THE PROBABILITY
(> 33%) OF THE MORE LIKELY CATEGORY (B OR A).  PROBABILITY OF N IS
ALWAYS < 40%.

THE PRECIPITATION MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING
WETTER (GREEN, "A"), DRIER (TAN, "B"), OR CLOSE TO (UNSHADED, "N")
HISTORICAL MEDIAN VALUES FOR THE CALENDAR PERIOD OF THE FORECAST
(DASHES, "INCHES").  LABELS ON THE SHADED LINES GIVE THE PROBABILITY
(> 33%) OF THE MORE LIKELY CATEGORY (B OR A).  PROBABILITY OF N IS
ALWAYS < 40%.

IN THE SOUTHWEST AND OTHER CLIMATOLOGICALLY DRY REGIONS - THERE WILL
BE A GREATER THAN 33.3% CHANCE OF NO PRECIPITATION AND OCCASIONALLY
EVEN A NORMAL (I.E. MEDIAN) VALUE OF ZERO - ESPECIALLY DURING THE DRY
SEASONS.  IN SUCH CASES A FORECAST OF NEAR NORMAL IS EFFECTIVELY A
FORECAST OF LITTLE OR NO PRECIPITATION.

THE CLIMATE PREDICTION CENTER USES 1981-2010 BASE PERIOD MEANS FOR
TEMPERATURE...PRECIPITATION...AND 500-HPA HEIGHTS AS REFERENCE IN
THE CLIMATE OUTLOOKS.

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON MAY
19

ANALOGS TO THE 5 DAY MEAN OBSERVED PATTERN CENTERED 3 DAYS AGO (D-3)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
19580408 - 19940502 - 19530510 - 19940424 - 19780429


ANALOGS TO THE 7 DAY MEAN OBSERVED PATTERN CENTERED 4 DAYS AGO (D-4)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 7 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
19580407 - 19530511 - 19940501 - 19940425 - 19950413


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 04 - 08 2016

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    N     OREGON      A    A     NRN CALIF   A    A
SRN CALIF   B    A     IDAHO       A    A     NEVADA      A    A
W MONTANA   A    N     E MONTANA   A    N     WYOMING     A    A
UTAH        N    A     ARIZONA     B    A     COLORADO    N    A
NEW MEXICO  B    A     N DAKOTA    A    B     S DAKOTA    A    B
NEBRASKA    A    B     KANSAS      N    B     OKLAHOMA    B    B
N TEXAS     B    B     S TEXAS     B    N     W TEXAS     B    N
MINNESOTA   A    B     IOWA        A    B     MISSOURI    N    B
ARKANSAS    B    B     LOUISIANA   B    B     WISCONSIN   A    B
ILLINOIS    N    B     MISSISSIPPI B    B     MICHIGAN    N    B
INDIANA     B    B     OHIO        B    B     KENTUCKY    B    B
TENNESSEE   B    B     ALABAMA     B    B     NEW YORK    N    B
VERMONT     N    N     NEW HAMP    N    N     MAINE       N    N
MASS        A    N     CONN        N    N     RHODE IS    A    N
PENN        B    B     NEW JERSEY  B    B     W VIRGINIA  B    B
MARYLAND    B    B     DELAWARE    B    B     VIRGINIA    B    B
N CAROLINA  B    B     S CAROLINA  B    N     GEORGIA     B    N
FL PNHDL    B    N     FL PENIN    B    A     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 06 - 12 2016

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    N     OREGON      A    A     NRN CALIF   A    A
SRN CALIF   B    A     IDAHO       A    A     NEVADA      A    A
W MONTANA   A    A     E MONTANA   A    A     WYOMING     A    A
UTAH        B    A     ARIZONA     B    A     COLORADO    N    A
NEW MEXICO  B    A     N DAKOTA    A    N     S DAKOTA    A    N
NEBRASKA    A    N     KANSAS      A    N     OKLAHOMA    N    N
N TEXAS     B    N     S TEXAS     B    N     W TEXAS     B    N
MINNESOTA   A    N     IOWA        A    N     MISSOURI    A    B
ARKANSAS    N    B     LOUISIANA   B    N     WISCONSIN   A    N
ILLINOIS    A    B     MISSISSIPPI N    B     MICHIGAN    A    N
INDIANA     A    B     OHIO        A    B     KENTUCKY    A    B
TENNESSEE   N    B     ALABAMA     N    B     NEW YORK    A    B
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    N
MASS        A    N     CONN        A    N     RHODE IS    A    N
PENN        A    B     NEW JERSEY  A    B     W VIRGINIA  A    B
MARYLAND    A    B     DELAWARE    A    B     VIRGINIA    N    B
N CAROLINA  N    B     S CAROLINA  N    B     GEORGIA     N    B
FL PNHDL    N    B     FL PENIN    N    B     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A

                           LEGEND
TEMPS WITH RESPECT TO NORMAL     PCPN WITH RESPECT TO MEDIAN
A - ABOVE   N  - NEAR NORMAL     A - ABOVE   N - NEAR MEDIAN
B - BELOW                        B - BELOW

THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.

FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS
PMDMRD.

$$






000
FXUS06 KWBC 281935
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU APRIL 28 2016

6-10 DAY OUTLOOK FOR MAY 04 - 08 2016

TODAY`S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA
CIRCULATION PATTERN OVER NORTH AMERICA DURING THE 6-10 DAY PERIOD. TROUGHS ARE
FORECAST OVER THE ALEUTIAN ISLANDS, NEAR THE SOUTHERN CALIFORNIA COAST, AND
OVER EASTERN NORTH AMERICA, WHILE A RIDGE IS FORECAST OVER WESTERN CANADA.
TODAY`S MODEL 500-HPA BLENDED HEIGHT CHART INDICATES ABOVE-NORMAL HEIGHTS OVER
THE NORTHWEST CONUS AND BELOW-NORMAL HEIGHTS OVER REMAINING U.S. REGIONS.

ENHANCED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ARE FORECAST OVER THE
NORTHERN CONUS FROM THE PACIFIC COAST TO THE UPPER MISSISSIPPI VALLEY, DUE TO
ABOVE-NORMAL HEIGHTS OVER THE REGION. ENHANCED PROBABILITIES OF BELOW-NORMAL
TEMPERATURES ARE INDICATED ACROSS THE SOUTHERN CONUS AND NORTHWARD INTO THE
OHIO VALLEY AND MID-ATLANTIC STATES, WHERE 500-HPA HEIGHTS ARE BELOW-NORMAL.
ANOMALOUS SOUTHERLY FLOW, AHEAD OF THE TROUGH OVER THE EAST, ENHANCES CHANCES
OF ABOVE-NORMAL TEMPERATURES ALONG THE NEW ENGLAND COAST. ANOMALOUS SOUTHERLY
CIRCULATION AHEAD OF THE TROUGH OVER THE ALEUTIAN ISLANDS ENHANCES THE
PROBABILITIES OF ABOVE-NORMAL TEMPERATURES OVER ALASKA.

ABOVE MEDIAN PRECIPITATION IS MOST LIKELY FOR MUCH OF THE WEST IN ASSOCIATION
WITH THE TROUGH PREDICTED NEAR THE PACIFIC COAST. ENHANCED PROBABILITIES OF
BELOW-MEDIAN PRECIPITATION ARE INDICATED OVER MOST OF THE U.S. EAST BEHIND THE
PREDICTED TROUGH AXIS OVER THE REGION. NEAR OR ABOVE-MEDIAN PRECIPITATION IS
FAVORED IN SOME REGIONS OF THE SOUTHEAST AND NORTHEAST AHEAD OF THE TROUGH.
ABOVE-MEDIAN PRECIPITATION IS MOST LIKELY FOR MOST OF ALASKA, WITH THE
EXCEPTION OF THE WEST COAST, AHEAD OF THE TROUGH OVER THE ALEUTIAN ISLANDS.

TODAY`S OFFICIAL 500-HPA BLEND CONSISTS OF 10% OF TODAY`S 0Z GFS ENSEMBLE MEAN
CENTERED ON DAY 8, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF
TODAY`S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 40% OF TODAY`S 0Z EUROPEAN
ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF TODAY`S OPERATIONAL 0Z ECMWF CENTERED ON
DAY 8, AND 20% OF TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8


FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE MODELS AND TOOLS.

8-14 DAY OUTLOOK FOR MAY 06 - 12 2016

TODAY`S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA
CIRCULATION PATTERN OVER NORTH AMERICA DURING THE WEEK 2 PERIOD. TROUGHS
PERSIST IN THE FORECAST OVER THE ALEUTIAN ISLANDS, NEAR THE SOUTHWEST, AND OVER
EASTERN NORTH AMERICA, WHILE A RIDGE IS FORECAST OVER WESTERN CANADA.
ABOVE-NORMAL 500-HPA HEIGHTS PERSIST INTO WEEK 2 OVER THE NORTHWEST CONUS,
WHILE BELOW-NORMAL HEIGHTS REMAIN OVER THE SOUTHWEST. BELOW-NORMAL HEIGHT
ANOMALIES OVER THE EAST HAVE DECREASED SUBSTANTIALLY IN MAGNITUDE FOR THE 8-14
DAY PERIOD.

ENHANCED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES CONTINUE ACROSS THE PACIFIC
NORTHWEST EASTWARD INTO THE NORTHERN AND CENTRAL PLAINS STATES. ABOVE-NORMAL
TEMPERATURES ARE MOST LIKELY OVER THE NORTHEAST EXTENDING TO THE ATLANTIC COAST
FROM VIRGINIA TO MAINE, WITH A WEAKENING OF ANOMALIES RELATED TO THE TROUGH
OVER THE EAST. ENHANCED PROBABILITIES OF BELOW-NORMAL TEMPERATURES CONTINUE
INTO THE 8-14 DAY PERIOD OVER THE SOUTHWEST, AND EASTWARD INTO TEXAS AND
LOUISIANA, WHILE NEAR-NORMAL TEMPERATURES ARE MOST LIKELY OVER MOST OF THE
SOUTHEAST RELATED TO THE WEAK TROUGH OVER THE REGION. ABOVE-NORMAL TEMPERATURES
CONTINUE TO BE MOST LIKELY FOR ALASKA FOR WEEK 2.

THE FORECAST PRECIPITATION PATTERN FOR WEEK 2 IS SIMILAR TO THE FORECAST FOR
THE 6-10 DAY PERIOD, WITH ABOVE-MEDIAN PRECIPITATION OVER MUCH OF THE WEST AND
BELOW-MEDIAN PRECIPITATION OVER MUCH OF THE EAST. PROBABILITIES OF BELOW-MEDIAN
PRECIPITATION HAVE DECREASED OVER NORTHERN REGIONS OF THE EAST WITH A MORE
ZONAL CIRCULATION PREDICTED FOE WEEK 2. ABOVE-MEDIAN PRECIPITATION IS PREDICTED
TO CONTINUE INTO THE 8-14 DAY PERIOD FOR MOST OF ALASKA.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 10% OF TODAY`S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 11, 20% OF TODAY`S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY
11, 50% OF TODAY`S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 20% OF
TODAY`S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11


FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOVE AVERAGE, 4 OUT OF 5, DUE
TO GOOD AGREEMENT AMONG THE MODELS AND TOOLS.

FORECASTER: CPC FORECASTER

NOTES:


AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OCCASIONALLY MANUAL
INTERVENTION IS NECESSARY TO ADDRESS QUALITY CONTROL AND CONSISTENCY ISSUES.
IN THESE CASES, FORECASTS ARE MANUALLY DRAWN BUT A FULL DISCUSSION IS NOT
ISSUED.

THE NOTATION FOR THE CATEGORICAL FORECAST INDICATED ON THE MAPS IS
THE SAME AS THAT IN THE TABLES: A-ABOVE   N-NEAR NORMAL   B-BELOW

THE TEMPERATURE MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WARMER
(ORANGE, "A"), COLDER (BLUE, "B"), OR CLOSE TO (UNSHADED, "N")
HISTORICAL AVERAGE VALUES FOR THE CALENDAR PERIOD OF THE FORECAST
(DASHES, "F").  LABELS ON THE SHADED LINES GIVE THE PROBABILITY
(> 33%) OF THE MORE LIKELY CATEGORY (B OR A).  PROBABILITY OF N IS
ALWAYS < 40%.

THE PRECIPITATION MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING
WETTER (GREEN, "A"), DRIER (TAN, "B"), OR CLOSE TO (UNSHADED, "N")
HISTORICAL MEDIAN VALUES FOR THE CALENDAR PERIOD OF THE FORECAST
(DASHES, "INCHES").  LABELS ON THE SHADED LINES GIVE THE PROBABILITY
(> 33%) OF THE MORE LIKELY CATEGORY (B OR A).  PROBABILITY OF N IS
ALWAYS < 40%.

IN THE SOUTHWEST AND OTHER CLIMATOLOGICALLY DRY REGIONS - THERE WILL
BE A GREATER THAN 33.3% CHANCE OF NO PRECIPITATION AND OCCASIONALLY
EVEN A NORMAL (I.E. MEDIAN) VALUE OF ZERO - ESPECIALLY DURING THE DRY
SEASONS.  IN SUCH CASES A FORECAST OF NEAR NORMAL IS EFFECTIVELY A
FORECAST OF LITTLE OR NO PRECIPITATION.

THE CLIMATE PREDICTION CENTER USES 1981-2010 BASE PERIOD MEANS FOR
TEMPERATURE...PRECIPITATION...AND 500-HPA HEIGHTS AS REFERENCE IN
THE CLIMATE OUTLOOKS.

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON MAY
19

ANALOGS TO THE 5 DAY MEAN OBSERVED PATTERN CENTERED 3 DAYS AGO (D-3)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
19580408 - 19940502 - 19530510 - 19940424 - 19780429


ANALOGS TO THE 7 DAY MEAN OBSERVED PATTERN CENTERED 4 DAYS AGO (D-4)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 7 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
19580407 - 19530511 - 19940501 - 19940425 - 19950413


6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 04 - 08 2016

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    N     OREGON      A    A     NRN CALIF   A    A
SRN CALIF   B    A     IDAHO       A    A     NEVADA      A    A
W MONTANA   A    N     E MONTANA   A    N     WYOMING     A    A
UTAH        N    A     ARIZONA     B    A     COLORADO    N    A
NEW MEXICO  B    A     N DAKOTA    A    B     S DAKOTA    A    B
NEBRASKA    A    B     KANSAS      N    B     OKLAHOMA    B    B
N TEXAS     B    B     S TEXAS     B    N     W TEXAS     B    N
MINNESOTA   A    B     IOWA        A    B     MISSOURI    N    B
ARKANSAS    B    B     LOUISIANA   B    B     WISCONSIN   A    B
ILLINOIS    N    B     MISSISSIPPI B    B     MICHIGAN    N    B
INDIANA     B    B     OHIO        B    B     KENTUCKY    B    B
TENNESSEE   B    B     ALABAMA     B    B     NEW YORK    N    B
VERMONT     N    N     NEW HAMP    N    N     MAINE       N    N
MASS        A    N     CONN        N    N     RHODE IS    A    N
PENN        B    B     NEW JERSEY  B    B     W VIRGINIA  B    B
MARYLAND    B    B     DELAWARE    B    B     VIRGINIA    B    B
N CAROLINA  B    B     S CAROLINA  B    N     GEORGIA     B    N
FL PNHDL    B    N     FL PENIN    B    A     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A



8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 06 - 12 2016

STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN
WASHINGTON  A    N     OREGON      A    A     NRN CALIF   A    A
SRN CALIF   B    A     IDAHO       A    A     NEVADA      A    A
W MONTANA   A    A     E MONTANA   A    A     WYOMING     A    A
UTAH        B    A     ARIZONA     B    A     COLORADO    N    A
NEW MEXICO  B    A     N DAKOTA    A    N     S DAKOTA    A    N
NEBRASKA    A    N     KANSAS      A    N     OKLAHOMA    N    N
N TEXAS     B    N     S TEXAS     B    N     W TEXAS     B    N
MINNESOTA   A    N     IOWA        A    N     MISSOURI    A    B
ARKANSAS    N    B     LOUISIANA   B    N     WISCONSIN   A    N
ILLINOIS    A    B     MISSISSIPPI N    B     MICHIGAN    A    N
INDIANA     A    B     OHIO        A    B     KENTUCKY    A    B
TENNESSEE   N    B     ALABAMA     N    B     NEW YORK    A    B
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    N
MASS        A    N     CONN        A    N     RHODE IS    A    N
PENN        A    B     NEW JERSEY  A    B     W VIRGINIA  A    B
MARYLAND    A    B     DELAWARE    A    B     VIRGINIA    N    B
N CAROLINA  N    B     S CAROLINA  N    B     GEORGIA     N    B
FL PNHDL    N    B     FL PENIN    N    B     AK N SLOPE  A    A
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    A
AK S INT    A    A     AK SO COAST A    A     AK PNHDL    A    A

                           LEGEND
TEMPS WITH RESPECT TO NORMAL     PCPN WITH RESPECT TO MEDIAN
A - ABOVE   N  - NEAR NORMAL     A - ABOVE   N - NEAR MEDIAN
B - BELOW                        B - BELOW

THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.

FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS
PMDMRD.

$$






000
FXCA20 KWBC 281825
PMDCA

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
224 PM EDT THU APR 28 2016

TROPICAL DISCUSSION FROM APRIL 28/12UTC: MID/UPPER LEVEL RIDGE
REMAINS WELL ENTRENCHED ACROSS WESTERN PORTIONS OF THE
DOMAIN...ENVELOPING CENTRAL/ SOUTHERN MEXICO-THE GULF AND CENTRAL
AMERICA. THE MID LEVEL AXIS ANCHORS ON A MEANDERING HIGH TO THE
SOUTH-SOUTHWEST OF GUERRERO MEXICO...WHERE IT IS TO REMAIN OVER
THE NEXT FEW DAYS. THROUGH FRIDAY MORNING THE RIDGE TENDS TO BUILD
NORTH ACROSS THE GULF INTO THE CENTRAL USA AS A HIGH AMPLITUDE
TROUGH PROPAGATES ACROSS THE WESTERN USA. BUT IT IS TO THEN
FLATTEN ON SATURDAY AS THE TROUGH RELOCATES TO THE CENTRAL USA.
THE RIDGE ALOFT IS TO INHIBIT DEEP CONVECTIVE DEVELOPMENT ACROSS
MOST OF MEXICO. OVER CENTRAL AMERICA IT WILL BE STRONG ENOUGH TO
DELAY...BUT NOT SUPPRESS...THE ONSET OF AFTERNOON CONVECTION.
ACTIVITY WILL BUILD BETWEEN SOUTHERN CHIAPAS AND WESTERN
NICARAGUA...WITH RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15.
LOCALLY HIGHER AMOUNTS ARE TO DEVELOP BETWEEN SOUTHEAST
HONDURAS-NORTHWEST NICARAGUA AS LATE EVENING CONVECTION CLUSTERS
ACROSS THE GULF OF FONSECA. IN THIS AREA EXPECTING RAINFALL
AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM. THROUGH SATURDAY
AFTERNOON...HOWEVER...THE DAILY MAXIMA WILL DECREASE TO 20-30MM AS
THE TRADE WINDS CAP STRENGTHENS.

UNDER THE STEERING INFLUENCE OF THE RIDGE TO THE WEST...SHORT WAVE
TROUGHS ARE FORECAST TO STREAM ACROSS THE BAHAMAS INTO THE
NORTHERN CARIBBEAN ISLES. ONE MOVES ACROSS HISPANIOLA TO PUERTO
RICO TODAY...WHILE A DEEPER ONE OVER THE SOUTHEAST USA EJECTS
ACROSS THE BAHAMAS TO HISPANIOLA LATER ON FRIDAY. IT REACHES
PUERTO RICO EARLY ON SATURDAY. THE INFLOW OF SHORT WAVE ENERGY
WILL THEN SUSTAIN THE GRADUAL AMPLIFICATION OF A TROUGH ACROSS THE
BAHAMAS-CUBA-HISPANIOLA DURING THE DAY ON SATURDAY. A SUBTROPICAL
JET IS TO GRADUALLY REPOSITION OVER THE NORTHERN CARIBBEAN AS IT
ROUNDS THE BASE OF THE TROUGH. THE TROUGH AND SUBTROPICAL JET
MAXIMA ARE TO SUSTAIN AN UPPER DIVERGENT PATTERN ACROSS
HISPANIOLA-PUERTO RICO-VIRGIN ISLES AND THE NORTHERN LEEWARD
ISLANDS.

AT LOW LEVELS...UNDER INFLUENCE OF THE BROAD MID/UPPER TROUGH OVER
THE WESTERN ATLANTIC...AN INDUCED/INVERTED TROUGH IS TO EXTEND
NORTH ALONG 75W/77W. A RIDGE LIES OVER THE TROPICAL ATLANTIC TO
THE EAST OF THE LESSER ANTILLES...WITH THE MSG DUST PRODUCT
SHOWING A SAHARAN AIR LAYER (SAL)/DUST PROPAGATING ACROSS THE
TROPICAL ATLANTIC TO JUST EAST OF THE LESSER ANTILLES EARLY THIS
MORNING. THE SAL IS TO REMAIN MOSTLY TO THE EAST OF THE
ISLANDS...WHILE THE TROUGH/RIDGE FAVORS A MOIST ADVECTIVE PATTERN
ACROSS THE CENTRAL CARIBBEAN INTO PUERTO RICO-DOMINICAN REPUBLIC.
IN THIS AREA THE PWAT CONTENT IS TO PEAK AROUND 50MM OVER THE NEXT
FEW DAYS. ALSO...AT 700 HPA...A WEST-SOUTHWESTERLY FLOW IS
EXPECTED THROUGH SATURDAY EVENING...ADDING SHEAR TO THE MIX. THIS
COMBINES WITH INFLOW OF MID LEVEL VORTICES AND FAVORABLE JET
DYNAMICS TO SUSTAIN ENVIRONMENTAL CONDITIONS THAT ARE TO REMAIN
HIGHLY FAVORABLE AND CONDUCIVE TO ORGANIZED DEEP CONVECTION.
ACROSS PUERTO RICO AND HISPANIOLA EXPECTING RAINFALL AMOUNTS OF
15-20MM/DAY AND MAXIMA OF 35-70MM/DAY THROUGH SATURDAY MORNING. ON
SATURDAY TO SUNDAY THIS WILL INCREASE TO 25-50MM/DAY AND MAXIMA OF
75-125MM.

SOUTH OVER THE DOMAIN...THE EASTERN PACIFIC ITCZ LIES NORTH OF ITS
CLIMATOLOGICAL POSITION ALONG 08N/09N INTO SOUTHERN CENTRAL
AMERICA/NORTHERN SOUTH AMERICA. THIS IS ENHANCING LOW LEVEL
MOISTURE CONVERGENCE ACROSS PANAMA AND COSTA RICA...WHERE WE
EXPECT RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF 15-25MM. MOST
ACTIVE IS TO CLUSTER ALONG THE CONTINENTAL DIVIDE. OVER NORTHWEST
COLOMBIA TO NORTHWEST VENEZUELA EXPECTING RAINFALL AMOUNTS OF
10-15MM/DAY AND MAXIMA OF 20-35MM THROUGH FRIDAY MORNING...AND
MAXIMA OF 20-40MM THEREAFTER. ON THE CAUCA/CAUCA VALLEY TO THE
SOUTHWEST EXPECTING RAINFALL AMOUNTS OF 05-10MM/DAY AND MAXIMA OF
15-20MM. OVER NORTHERN VENEZUELA ITCZ/NET RELATED CONVECTION WILL
SUSTAIN RAINFALL AMOUNTS OF 10-15MM/DAY AND MAXIMA OF 20-40MM.
THROUGH SATURDAY THIS WILL INCREASE TO 25-50MM/DAY AND MAXIMA OF
75-100MM CLUSTERING TO THE NORTHWEST. ACTIVITY IS TO ALSO SPREAD
NORTH INTO THE ABC ISLES ON FRIDAY...WITH ACCUMULATION OF
05-10MM/DAY AND MAXIMA OF 15MM...INCREASING TO 10-15MM/DAY AND
MAXIMA OF 20-40MM ON SATURDAY. OVER SOUTHERN COLOMBIA-AMAZONAS IN
VENEZUELA...A SOUTHERN HEMISPHERE PREFRONTAL SHEAR LINE WILL FAVOR
RAINFALL AMOUNTS OF 25-50MM/DAY AND MAXIMA OF 75-150MM THROUGH
FRIDAY MORNING. ON FRIDAY TO SATURDAY THE FOCUS OF THE HEAVY
CONVECTION SHIFTS NORTH TO PIEDEMONTE LLANERO IN COLOMBIA-CENTRAL
VENEZUELA/RORAIMA HIGHLANDS...WITH RAINFALL AMOUNTS OF 25-50MM/DAY
AND MAXIMA OF 75-125MM. ON SATURDAY TO SUNDAY THIS DECREASES TO
10-15MM/DAY AND MAXIMA OF 20-45MM.

TROPICAL/EASTERLY WAVES INITIALIZED AT 12UTC.
INITIAL    24    36    48    60    72    84    96         TYPE
NONE

CARDOS...SMN (MEXICO)
CABANERIT...INAMEH (VENEZUELA)
DAVISON/GALVEZ...WPC (USA)
$$







000
FXUS02 KWBC 281559
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1158 AM EDT THU APR 28 2016

VALID 12Z SUN MAY 01 2016 - 12Z THU MAY 05 2016

...OVERVIEW...

THE 00Z/06Z CYCLE OF GUIDANCE MAINTAINS THE SAME THEME FROM RECENT
RUNS... NAMELY A FAIRLY RAPID DISSIPATION OF A BRIEF WRN NOAM REX
BLOCK CONFIGURATION FOLLOWED BY INCREASINGLY AMPLIFIED ERN NOAM
TROUGHING IN RESPONSE TO A STRONG ERN PAC/WEST COAST TROUGH AND
W-CNTRL NOAM RIDGE.  THERE IS STILL GOOD AGREEMENT FOR THE LARGE
SCALE EVOLUTION IN PRINCIPLE BUT PERSISTENT UNCERTAINTY IN SOME
EMBEDDED DETAILS THAT WILL HAVE A MEANINGFUL IMPACT ON SENSIBLE
WEATHER OVER SOME AREAS.


...GUIDANCE EVALUATION/PREFERENCES...

DIFFS OVER THE ERN PAC/WRN U.S. ARE GENERALLY MODEST.  INITIAL
GRTBASIN/SOUTHWEST UPR LOW ENERGY SHOULD OPEN UP BY DAY 4 MON AND
THEN BE REPLACED BY A STRENGTHENING RIDGE WHOSE AXIS SHOULD REACH
THE ROCKIES HIGH PLAINS BY DAY 7 THU.  WITH THE ERN PAC TROUGH
NEARING THE WEST COAST THERE HAS BEEN A SLIGHTLY FASTER TREND OVER
THE PAST 1-2 DAYS.  THIS MIGHT FAVOR LEANING AWAY FROM THE 00Z
NAEFS MEAN THAT IS A TAD SLOWER THAN THE GUIDANCE AVG.  HOWEVER IT
REMAINS TO BE SEEN HOW MUCH LONGER THIS FASTER TREND CAN CONTINUE
GIVEN THE STRONGLY AMPLIFIED NATURE OF THE PATTERN BY LATE IN THE
PERIOD... SO WOULD ALSO TEND TO LEAN AWAY FROM THE 06Z GFS THAT IS
A BIT FASTER THAN MOST OTHER SOLNS WITH LEADING HGT FALLS.  AT THE
MOMENT THERE IS A DECENT SIGNAL THAT AN EMBEDDED UPR LOW MAY CLOSE
OFF NEAR THE CA COAST BY NEXT THU.

SOMEWHAT GREATER SPREAD/UNCERTAINTY EXIST FOR SOME DETAILS OVER
THE ERN HALF OF THE LOWER 48.  IN THE PAST COUPLE DAYS THERE HAS
BEEN A PRONOUNCED FASTER TREND WITH THE SYSTEM FCST TO TRACK FROM
THE MS VLY/OH VLY REGION INTO THE CANADIAN MARITIMES SUN-TUE.
MODEL/ENSEMBLE CLUSTERING IS BETTER THAN IN PREVIOUS DAYS BUT
LINGERING ISSUES WITH STREAM INTERACTION CONTINUE TO TEMPER
CONFIDENCE.  COMPONENTS ALOFT AFFECTING SFC EVOLUTION WILL INCLUDE
INITIAL ENERGY EJECTING FROM THE PLAINS... GRTLKS/ERN CANADA
FLOW... AND MORE INDIRECTLY THE UPSTREAM SHRTWV ENERGY TRACKING
SEWD FROM CNTRL CANADA.  PREFER TO ADHERE TO THE MAJORITY CLUSTER
THAT INCLUDES THE 00Z GFS/ECMWF-EC MEAN/UKMET AND 00Z/06Z GEFS
MEANS.  IN SPITE OF RECENT TRENDS THE COMPLEXITY OF THE FCST
FAVORS WAITING FOR MORE CONFIRMATION BEFORE TRENDING AS FAST AS
THE 06Z GFS.

BEHIND THIS SYSTEM GUIDANCE IS MIXED AS TO WHAT DEGREE THE
COMBINATION OF EJECTING WRN UPR LOW ENERGY AND ERN U.S. TROUGH
ENERGY WILL SUPPORT FRONTAL WAVINESS OVER THE SERN STATES BY DAY 5
TUE.  BASED ON THE FULL ARRAY OF CURRENT AND RECENT GUIDANCE THE
BEST SOLN APPEARS TO LIE BTWN THE SUPPRESSED GFS RUNS AND WELL
NWD/NWWD ECMWF RUNS.  TOWARD WED-THU THE AMPLIFYING UPR TROUGH
SUPPORTS AN AXIS OF LOW PRESSURE ALONG THE EAST COAST... WITH
DETAILS EVENTUALLY COMING INTO CLEARER FOCUS AS SHRTWV EVOLUTION
ALOFT BECOMES BETTER RESOLVED.  UPSTREAM THE GUIDANCE HAS BEEN
CONSISTENT WITH THE IDEA OF A COLD FRONT DROPPING SEWD THROUGH THE
UPR MS VLY/GRTLKS AND BEYOND BUT WITH SOME RUN TO RUN TIMING
DIFFS.  TOWARD THE END OF THE PERIOD THE 06Z GFS IS THE ONE
PARTICULARLY QUESTIONABLE PIECE OF GUIDANCE AS IT BECOMES WEAKER
THAN CONSENSUS WITH THE CORE OF THE ERN TROUGH ALOFT AND TRACKS S
OF CONSENSUS WITH A DEEP COMPACT UPR LOW OVER CANADA.

BASED ON DECENT CLUSTERING THROUGH MID-PERIOD THE LATEST WPC FCST
REFLECTS A CONSENSUS BLEND THAT EMPHASIZES THE 00Z GFS/ECMWF/UKMET
MORE THAN THE GEFS/ECMWF MEANS THROUGH DAY 5 TUE.  DECREASING
CONFIDENCE IN SPECIFICS WITH TIME LEADS TO INCREASING WEIGHT OF
THE ENSEMBLE MEANS RELATIVE TO THE 00Z GFS/ECMWF BY DAYS 6-7
WED-THU.

...WEATHER HIGHLIGHTS/THREATS...

RNFL OF VARYING INTENSITY WILL ACCOMPANY THE SYSTEM TRACKING
THROUGH THE EAST SUN ONWARD.  THOUGH NOT TO THE EXTENT SEEN IN
PREVIOUS DAYS THERE IS STILL A FAIR AMOUNT OF SPREAD REGARDING
FOCUS OF HEAVIEST ACTIVITY.  MEANWHILE THE UPR LOW INITIALLY OVER
THE WEST WILL GENERATE AREAS OF ENHANCED PCPN OVER PORTIONS OF THE
SOUTHWEST/FOUR CORNERS/SRN ROCKIES FROM SUN INTO EARLY NEXT WEEK.
SOME SNOW IS PSBL AT HIGHER ELEVS.  OPENING UP/EJECTION OF THIS
ENERGY SHOULD SUPPORT SOME POCKETS OF LOCALLY HVY RNFL ACROSS THE
SRN PLAINS AND WRN-CNTRL GULF COAST.  CONFIDENCE IS BELOW AVG FOR
COVERAGE/AMTS OF RNFL THAT MAY SPREAD EWD/NEWD FROM THE SRN PLAINS
AFTER SUN.  TOWARD THE LATTER HALF OF THE PERIOD THE WEST COAST
STATES SHOULD SEE A GRADUAL INCREASE IN MSTR AHEAD OF THE
APPROACHING UPR TROUGH.

EXPECT THE WRN-CNTRL STATES TO SEE THE MOST EXTREME ANOMALIES FOR
TEMPS DURING THE PERIOD.  ON THE COLD SIDE A CHILLY SFC RIDGE OVER
THE HIGH PLAINS WILL LIKELY SUPPORT HIGHS AS MUCH AS 20-30F BELOW
NORMAL AT SOME LOCATIONS ON SUN WITH MINUS 10-25F ANOMALIES
PERSISTING INTO MON.  ON THE OTHER HAND THE NWRN STATES SHOULD SEE
MULTIPLE DAYS WITH HIGHS 10-20F ABOVE NORMAL... WITH SOME OF THIS
WARMTH EVENTUALLY EXTENDING INTO THE NRN HIGH PLAINS.

RAUSCH

$$







000
FXUS02 KWBC 281559
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1158 AM EDT THU APR 28 2016

VALID 12Z SUN MAY 01 2016 - 12Z THU MAY 05 2016

...OVERVIEW...

THE 00Z/06Z CYCLE OF GUIDANCE MAINTAINS THE SAME THEME FROM RECENT
RUNS... NAMELY A FAIRLY RAPID DISSIPATION OF A BRIEF WRN NOAM REX
BLOCK CONFIGURATION FOLLOWED BY INCREASINGLY AMPLIFIED ERN NOAM
TROUGHING IN RESPONSE TO A STRONG ERN PAC/WEST COAST TROUGH AND
W-CNTRL NOAM RIDGE.  THERE IS STILL GOOD AGREEMENT FOR THE LARGE
SCALE EVOLUTION IN PRINCIPLE BUT PERSISTENT UNCERTAINTY IN SOME
EMBEDDED DETAILS THAT WILL HAVE A MEANINGFUL IMPACT ON SENSIBLE
WEATHER OVER SOME AREAS.


...GUIDANCE EVALUATION/PREFERENCES...

DIFFS OVER THE ERN PAC/WRN U.S. ARE GENERALLY MODEST.  INITIAL
GRTBASIN/SOUTHWEST UPR LOW ENERGY SHOULD OPEN UP BY DAY 4 MON AND
THEN BE REPLACED BY A STRENGTHENING RIDGE WHOSE AXIS SHOULD REACH
THE ROCKIES HIGH PLAINS BY DAY 7 THU.  WITH THE ERN PAC TROUGH
NEARING THE WEST COAST THERE HAS BEEN A SLIGHTLY FASTER TREND OVER
THE PAST 1-2 DAYS.  THIS MIGHT FAVOR LEANING AWAY FROM THE 00Z
NAEFS MEAN THAT IS A TAD SLOWER THAN THE GUIDANCE AVG.  HOWEVER IT
REMAINS TO BE SEEN HOW MUCH LONGER THIS FASTER TREND CAN CONTINUE
GIVEN THE STRONGLY AMPLIFIED NATURE OF THE PATTERN BY LATE IN THE
PERIOD... SO WOULD ALSO TEND TO LEAN AWAY FROM THE 06Z GFS THAT IS
A BIT FASTER THAN MOST OTHER SOLNS WITH LEADING HGT FALLS.  AT THE
MOMENT THERE IS A DECENT SIGNAL THAT AN EMBEDDED UPR LOW MAY CLOSE
OFF NEAR THE CA COAST BY NEXT THU.

SOMEWHAT GREATER SPREAD/UNCERTAINTY EXIST FOR SOME DETAILS OVER
THE ERN HALF OF THE LOWER 48.  IN THE PAST COUPLE DAYS THERE HAS
BEEN A PRONOUNCED FASTER TREND WITH THE SYSTEM FCST TO TRACK FROM
THE MS VLY/OH VLY REGION INTO THE CANADIAN MARITIMES SUN-TUE.
MODEL/ENSEMBLE CLUSTERING IS BETTER THAN IN PREVIOUS DAYS BUT
LINGERING ISSUES WITH STREAM INTERACTION CONTINUE TO TEMPER
CONFIDENCE.  COMPONENTS ALOFT AFFECTING SFC EVOLUTION WILL INCLUDE
INITIAL ENERGY EJECTING FROM THE PLAINS... GRTLKS/ERN CANADA
FLOW... AND MORE INDIRECTLY THE UPSTREAM SHRTWV ENERGY TRACKING
SEWD FROM CNTRL CANADA.  PREFER TO ADHERE TO THE MAJORITY CLUSTER
THAT INCLUDES THE 00Z GFS/ECMWF-EC MEAN/UKMET AND 00Z/06Z GEFS
MEANS.  IN SPITE OF RECENT TRENDS THE COMPLEXITY OF THE FCST
FAVORS WAITING FOR MORE CONFIRMATION BEFORE TRENDING AS FAST AS
THE 06Z GFS.

BEHIND THIS SYSTEM GUIDANCE IS MIXED AS TO WHAT DEGREE THE
COMBINATION OF EJECTING WRN UPR LOW ENERGY AND ERN U.S. TROUGH
ENERGY WILL SUPPORT FRONTAL WAVINESS OVER THE SERN STATES BY DAY 5
TUE.  BASED ON THE FULL ARRAY OF CURRENT AND RECENT GUIDANCE THE
BEST SOLN APPEARS TO LIE BTWN THE SUPPRESSED GFS RUNS AND WELL
NWD/NWWD ECMWF RUNS.  TOWARD WED-THU THE AMPLIFYING UPR TROUGH
SUPPORTS AN AXIS OF LOW PRESSURE ALONG THE EAST COAST... WITH
DETAILS EVENTUALLY COMING INTO CLEARER FOCUS AS SHRTWV EVOLUTION
ALOFT BECOMES BETTER RESOLVED.  UPSTREAM THE GUIDANCE HAS BEEN
CONSISTENT WITH THE IDEA OF A COLD FRONT DROPPING SEWD THROUGH THE
UPR MS VLY/GRTLKS AND BEYOND BUT WITH SOME RUN TO RUN TIMING
DIFFS.  TOWARD THE END OF THE PERIOD THE 06Z GFS IS THE ONE
PARTICULARLY QUESTIONABLE PIECE OF GUIDANCE AS IT BECOMES WEAKER
THAN CONSENSUS WITH THE CORE OF THE ERN TROUGH ALOFT AND TRACKS S
OF CONSENSUS WITH A DEEP COMPACT UPR LOW OVER CANADA.

BASED ON DECENT CLUSTERING THROUGH MID-PERIOD THE LATEST WPC FCST
REFLECTS A CONSENSUS BLEND THAT EMPHASIZES THE 00Z GFS/ECMWF/UKMET
MORE THAN THE GEFS/ECMWF MEANS THROUGH DAY 5 TUE.  DECREASING
CONFIDENCE IN SPECIFICS WITH TIME LEADS TO INCREASING WEIGHT OF
THE ENSEMBLE MEANS RELATIVE TO THE 00Z GFS/ECMWF BY DAYS 6-7
WED-THU.

...WEATHER HIGHLIGHTS/THREATS...

RNFL OF VARYING INTENSITY WILL ACCOMPANY THE SYSTEM TRACKING
THROUGH THE EAST SUN ONWARD.  THOUGH NOT TO THE EXTENT SEEN IN
PREVIOUS DAYS THERE IS STILL A FAIR AMOUNT OF SPREAD REGARDING
FOCUS OF HEAVIEST ACTIVITY.  MEANWHILE THE UPR LOW INITIALLY OVER
THE WEST WILL GENERATE AREAS OF ENHANCED PCPN OVER PORTIONS OF THE
SOUTHWEST/FOUR CORNERS/SRN ROCKIES FROM SUN INTO EARLY NEXT WEEK.
SOME SNOW IS PSBL AT HIGHER ELEVS.  OPENING UP/EJECTION OF THIS
ENERGY SHOULD SUPPORT SOME POCKETS OF LOCALLY HVY RNFL ACROSS THE
SRN PLAINS AND WRN-CNTRL GULF COAST.  CONFIDENCE IS BELOW AVG FOR
COVERAGE/AMTS OF RNFL THAT MAY SPREAD EWD/NEWD FROM THE SRN PLAINS
AFTER SUN.  TOWARD THE LATTER HALF OF THE PERIOD THE WEST COAST
STATES SHOULD SEE A GRADUAL INCREASE IN MSTR AHEAD OF THE
APPROACHING UPR TROUGH.

EXPECT THE WRN-CNTRL STATES TO SEE THE MOST EXTREME ANOMALIES FOR
TEMPS DURING THE PERIOD.  ON THE COLD SIDE A CHILLY SFC RIDGE OVER
THE HIGH PLAINS WILL LIKELY SUPPORT HIGHS AS MUCH AS 20-30F BELOW
NORMAL AT SOME LOCATIONS ON SUN WITH MINUS 10-25F ANOMALIES
PERSISTING INTO MON.  ON THE OTHER HAND THE NWRN STATES SHOULD SEE
MULTIPLE DAYS WITH HIGHS 10-20F ABOVE NORMAL... WITH SOME OF THIS
WARMTH EVENTUALLY EXTENDING INTO THE NRN HIGH PLAINS.

RAUSCH

$$







000
FXSA20 KWBC 281356
PMDSA

SOUTH AMERICA SYNOPTIC DISCUSSION - INTERNATIONAL DESKS
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
955 AM EDT THU APR 28 2016

GFS DATA AT FTPPRD.NCEP.NOAA.GOV/PUB/DATA/NCCF/COM/GFS/PROD/

SYNOPSIS (VALID FROM APR 28 AT 0000 UTC): AT 200 HPA...HIGH
AMPLITUDE POLAR TROUGH DOMINATES THE WESTERN ATLANTIC AND MID
SECTIONS OF SOUTH AMERICA. THE TROUGH PRESSES AGAINST A WANING
CELL OF THE SUBTROPICAL RIDGE...WITH AXIS CONFINING TO CONTINENTAL
AREA TO THE NORTH OF 10S. UNDER INFLUENCE OF THE POLAR
TROUGH...CONVECTION IS SURGING ACROSS EQUATORIAL SOUTH AMERICA
WHILE CLUSTERING OVER NORTHERN PARA/RORAIMA-AMAZONAS IN BRASIL TO
NORTHERN PERU/EASTERN ECUADOR AND SOUTHERN COLOMBIA. HYDRO
ESTIMATORS SHOW RAIN RATES OF 20-30MM PER HOUR...WITH POTENTIAL
FOR HEAVY RAINFALL AMOUNTS TO AFFECT ECUADOR-COLOMBIA-VENEZUELA.

AT 250 HPA THE SOUTHERN POLAR LIES ALONG 66S 117W...A 150KT
MAXIMUM AT 67S 107W...67S 96W...66S 79W...58S 68W...50S
64W...EXITING AT 49S 58W. IT HAS A FINGER TO THE NORTH WITH
ENTRANCE AT 41S 54W...THEN ALONG 37S 54W...EXITING AT 33S 52W. THE
NORTHERN POLAR HAS ITS ENTRANCE AT 38S 122W...THEN ALONG 31S
117W...A 146KT MAXIMUM AT 33S 106W...A 162KE MAXIMUM AT 36S
97W...EXITING AT 39S 86W. IT REFORMS AT 35S 63W...CROSSING 30S
57W...28S 49W...35S 40W...A 151KT MAXIMUM AT 44S 33W...A 160KT
MAXIMUM AT 48S 23W...A 181KT MAXIMUM AT 49S 13W...AND 179KT
MAXIMUM AT 46S 03W. THE SUBTROPICAL JET LIES ALONG 22S 120W...A
138KT MAXIMUM AT 32S 97W...33S 85W...A 125KT MAXIMUM AT 32S
76W...27S 67W...EXITING AT 23S 59W. THE SUBTROPICAL JET REFORMS AT
21S 54W...THEN ALONG 23S 46W...A 134KT MAXIMUM AT 37S 34W...45S
26W...AND A 153KT MAXIMUM AT 43S 10W.

AT 500 HPA...BROAD TROUGH DOMINATES THE FLOW OVER THE EASTERN
PACIFIC...ENVELOPING AREA BETWEEN 125W-85W AND TO THE NORTH OF
54S. IN A SPLIT FLOW PATTERN A LOW AMPLITUDE RIDGE LIES TO THE
SOUTH...EXTENDING INTO THE POLAR ICE CAP AND THE BELLINGSHAUSEN
SEA. ANOTHER RIDGE EXTENDS ALONG THE COAST OF CHILE. A SHORT WAVE
TROUGH IN THE SOUTHERN STREAM EXTENDS ACROSS THE WEDDELL SEA TO
SOUTHERN PATAGONIA IN ARGENTINA. THIS IS INTERACTING WITH A LONG
WAVE TROUGH IN THE NORTHERN STREAM THAT EXTENDS TO THE NORTHWEST
FROM A CLOSED LOW AT 43S 48W... SOUTHERN STATES OF BRASIL-PARAGUAY
TO BOLIVIA.

AT LOW LEVELS...BROAD TROUGH DOMINATES THE FLOW ACROSS THE EASTERN
PACIFIC...WITH AXIS ANCHORING ON A DEEP 990 HPA LOW AT 42S 102W. A
RIDGE TO THE EAST EXTENDS NORTH TO SOUTH ALONG 80W...WHILE
ANCHORING ON A 1029 HPA HIGH AT 55S 81W AND A 1017 HPA HIGH AT 29S
82W. EAST OF THIS RIDGE...A TROUGH ON THE SOUTHERN STREAM EXTENDS
FROM THE WEDDELL SEA TO CENTRAL PATAGONIA IN ARGENTINA...WHILE
ORIGINATING ON AN OCCLUDING 978 HPA LOW AT 67S 36W. A TROUGH ON
THE NORTHERN STREAM ANCHORS ON A 998 HPA LOW AT 41S 46W...WITH A
POLAR FRONT THAT EXTENDS ALONG A 1002 HPA LOW AT 40S 30W...A 1010
HPA LOW AT 26S 40W...RIO DE JANEIRO/NORTHERN SAO PAULO...TOCANTINS
GOIAS/SOUTHERN PARA TO AMAZONAS IN BRASIL-CENTRAL PERU. THIS
SUSTAINS ORGANIZED DEEP CONVECTION ACROSS NORTHWEST SOUTH AMERICA.
A POLAR RIDGE TO THE SOUTH CENTERS ON A 1025 HPA HIGH AT 30S 64W.

AYALA...DINAC (PARAGUAY)
ENRIQUEZ...DGAC (ECUADOR)
DAVISON/GALVEZ...WPC (USA)
$$







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