688
FXUS06 KWBC 082003
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST THU FEBRUARY 08 2024
6-10 DAY OUTLOOK FOR FEB 14 - 18 2024
A MAJOR PATTERN CHANGE IS LIKELY DURING MID-FEBRUARY AS A NEGATIVE ARCTIC
OSCILLATION (AO) BECOMES ESTABLISHED. MODEL SOLUTIONS HAVE BEEN CONSISTENT ON
THIS TIMING WITH POSITIVE (NEGATIVE) 500-HPA HEIGHT ANOMALIES BECOMING
PREVALENT OVER THE HIGH (MIDDLE) LATITUDES OF NORTH AMERICA. THE MANUAL 500-HPA
HEIGHT BLEND (NEAR EQUAL WEIGHTING OF THE GEFS, ECMWF, AND CANADIAN ENSEMBLE
MEANS) DEPICTS HIGH AMPLITUDE TROUGHS OVER THE NORTHERN PACIFIC AND
NORTHWESTERN ATLANTIC AND A HIGH AMPLITUDE RIDGE EXTENDING FROM THE PACIFIC
NORTHWEST NORTHWARD TO EASTERN MAINLAND ALASKA. AN OVERALL COOLING TREND IS
FORECAST ACROSS THE CENTRAL AND EASTERN CONTIGUOUS U.S. (CONUS) DUE TO THE
NEGATIVE AO AND SURFACE HIGH PRESSURE SHIFTING SOUTH FROM CANADA. A SLIGHT LEAN
TOWARDS ABOVE-NORMAL TEMPERATURES IS FORECAST ACROSS THE UPPER MIDWEST WHERE
ABOVE-NORMAL TEMPERATURES MAY LINGER. AS ARCTIC HIGH PRESSURE BUILDS OVER
CANADA AND BEGINS TO EXPAND SOUTHWARD, ELEVATED BELOW-NORMAL TEMPERATURE
PROBABILITIES ARE FORECAST ACROSS THE NORTHERN ROCKIES AND NORTHERN GREAT
PLAINS. INCREASING PACIFIC FLOW FAVORS ABOVE-NORMAL TEMPERATURES ACROSS THE
PACIFIC NORTHWEST, MUCH OF CALIFORNIA, AND THE GREAT BASIN.
BY DAY 6 (FEBRUARY 14), A STRONG LOW PRESSURE SYSTEM IS FORECAST TO BE LOCATED
ACROSS THE CANADIAN MARITIMES. IN THE WAKE OF THIS LOW PRESSURE SYSTEM,
ANOMALOUS NORTHWESTERLY SURFACE FLOW IS FORECAST WHICH FAVORS BELOW-NORMAL
PRECIPITATION THROUGHOUT THE NORTHEAST, MID-ATLANTIC, AND MIDWEST. THE ENSEMBLE
MEANS ARE IN GOOD AGREEMENT THAT A SOUTHERN STREAM SHORTWAVE TROUGH CROSSES
NORTHERN MEXICO AND RESULTS IN SURFACE LOW DEVELOPMENT EITHER ALONG THE GULF
COAST OR GULF OF MEXICO BY DAY 9 (FEBRUARY 17). ALONG THE PREDICTED TRACK OF
THE SHORTWAVE TROUGH/LOW PRESSURE SYSTEM, INCREASED ABOVE-NORMAL PRECIPITATION
PROBABILITIES ARE FORECAST ACROSS THE SOUTHERN GREAT PLAINS, RIO GRANDE VALLEY,
GULF COAST STATES, AND SOUTHEAST. THERE IS HIGH UNCERTAINTY ON THE NORTHERN
EXTENT OF THE PRECIPITATION WITH LARGE ENSEMBLE SPREAD ON THE EXACT TRACK OF
THE LOW PRESSURE SYSTEM. FOLLOWING A BREAK IN THE HEAVY PRECIPITATION ACROSS
CALIFORNIA AND THE SOUTHWEST, A RETURN OF A WET PATTERN IS LIKELY FOR THESE
AREAS AS THE ANOMALOUS TROUGH SHIFTS CLOSER TO THE WEST COAST DURING THE LATTER
HALF OF FEBRUARY. PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION TAPER OFF TO THE
NORTH ACROSS THE WESTERN CONUS SINCE MODEL GUIDANCE REMAINS CONSISTENT THAT THE
PRIMARY STORM TRACK REMAINS SOUTH OF THE 40TH PARALLEL.
SOUTHERLY SURFACE FLOW FAVORS ABOVE-NORMAL TEMPERATURES THROUGHOUT ALASKA.
SINCE THE STORM TRACK ACROSS THE NORTH PACIFIC IS EXPECTED TO BE DISPLACED
SOUTHWARD WITH TIME, MODEL SOLUTIONS CONTINUE TO FEATURE A DRYING TREND WITH
INCREASED BELOW-NORMAL PRECIPITATION PROBABILITIES FORECAST FOR MUCH OF ALASKA.
A HIGHLY AMPLIFIED TROUGH OVER THE NORTH PACIFIC LEADS TO NORTHERLY SURFACE
LOW, PROMOTING INCREASED BELOW-NORMAL TEMPERATURE PROBABILITIES ACROSS HAWAII.
THE CONSOLIDATION TOOL SUPPORTS NEAR NORMAL PRECIPITATION.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 35% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 35% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD
AGREEMENT AMONG THE PRECIPITATION TOOLS OFFSET BY UNCERTAINTY ON THE MAGNITUDE
OF ANOMALOUS COLD OVERSPREADING THE CENTRAL AND EASTERN CONUS.
8-14 DAY OUTLOOK FOR FEB 16 - 22 2024
THE GEFS, ECMWF, AND CANADIAN ENSEMBLE MEANS MAINTAIN POSITIVE (NEGATIVE)
500-HPA HEIGHT ANOMALIES OVER THE HIGH (MIDDLE) LATITUDES OF NORTH AMERICA AS A
NEGATIVE AO IS LIKELY TO PERSIST THROUGH LATE FEBRUARY. A
JANUARY-FEBRUARY-MARCH COMPOSITE, WHEN A NEGATIVE AO OCCURRED DURING AN EL
NIñO, WAS A FACTOR IN THE 8-14 DAY TEMPERATURE OUTLOOK. ALSO GUIDANCE DERIVED
FROM TELECONNECTIONS UPON A POSITIVE 500-HPA HEIGHT ANOMALY OVER SOUTHERN
GREENLAND AND A PAIR OF PROMINENT NEGATIVE 500-HPA HEIGHT ANOMALIES ACROSS THE
NORTHERN ATLANTIC AND PACIFIC WERE USED. ALTHOUGH A COLDER PATTERN IS EXPECTED
ACROSS THE CENTRAL AND EASTERN CONUS COMPARED TO EARLY FEBRUARY, THE MAGNITUDE
OF THE ANOMALOUS COLD REMAINS UNCERTAIN AS THE REFORECAST GEFS AND ECMWF TOOLS
ARE WARMER THAN THEIR UNCALIBRATED OUTPUT AND THE ANALOG TOOL FROM THE MANUAL
500-HPA HEIGHT BLEND. THE TWO MOST LIKELY AREAS FOR BELOW-NORMAL TEMPERATURES
INCLUDE THE EASTERN CONUS DUE TO THE HIGH AMPLITUDE TROUGH NEAR THE EAST COAST
AND THE NORTHERN GREAT PLAINS WITH ARCTIC HIGH PRESSURE EXPANDING SOUTH FROM
CANADA. THE MEAN 7-DAY SURFACE PATTERN, NEGATIVE 500-HPA HEIGHT ANOMALIES, AND
SOUTHERN STREAM SHORTWAVE TROUGHS SUPPORT ELEVATED BELOW-NORMAL TEMPERATURE
PROBABILITIES ACROSS THE GREAT PLAINS AND SOUTHERN TIER OF THE CONUS. ENHANCED
PACIFIC FLOW FAVORS ABOVE-NORMAL TEMPERATURES ACROSS THE PACIFIC NORTHWEST,
NORTHERN CALIFORNIA, AND THE GREAT BASIN.
FORECAST CONFIDENCE REMAINS HIGH THAT A WET PATTERN RETURNS TO CALIFORNIA AND
THE SOUTHWEST AS AN AMPLIFIED 500-HPA TROUGH SHIFTS CLOSER TO THE WEST COAST.
THE ENSEMBLE MEANS DEPICT THE RENEWAL OF THIS WET PATTERN BY DAY 8 OR 9
(FEBRUARY 16 OR 17). TOTAL PRECIPITATION AMOUNTS FROM THE ENSEMBLE MEANS ARE
NEAR OR ABOVE 2 INCHES (LIQUID EQUIVALENT) ACROSS MUCH OF CALIFORNIA,
SUPPORTING ABOVE-NORMAL PRECIPITATION PROBABILITIES THAT EXCEED 60 PERCENT.
THESE RELATIVELY HIGH PROBABILITIES ALSO INCLUDE THE DRIER CLIMATOLOGY AREAS OF
THE DESERT SOUTHWEST. DUE TO THE LONGWAVE TROUGH AXIS SHIFTING CLOSER TO THE
WEST COAST, THERE IS AN INCREASED CHANCE OF SURFACE LOW DEVELOPMENT ACROSS THE
GREAT PLAINS WHERE ELEVATED ABOVE-NORMAL PRECIPITATION PROBABILITIES ARE
FORECAST. UPSLOPE FLOW ALSO SUPPORTS THE RELATIVELY WET PATTERN ACROSS THE
CENTRAL TO NORTHERN HIGH PLAINS. ONE OR TWO SHORTWAVE TROUGHS ARE FORECAST TO
AFFECT THE GULF COAST STATES AND SOUTHEAST WHICH FAVORS ABOVE-NORMAL
PRECIPITATION. SIMILAR TO THE 6-10 DAY PERIOD, THE NORTHERN EXTENT OF THE
PRECIPITATION IS UNCERTAIN BUT CHANCES FOR BELOW-NORMAL PRECIPITATION INCREASE
TO THE NORTH ACROSS THE OHIO VALLEY AND NORTHEAST.
DUE TO A PREDICTED TRANSITION FROM SOUTHERLY TO PERHAPS MORE EASTERLY FLOW
LATER IN WEEK-2, TEMPERATURE PROBABILITIES ARE LIMITED ACROSS ALASKA.
ABOVE-NORMAL TEMPERATURES ARE MORE LIKELY ACROSS THE WESTERN TWO-THIRDS OF THE
STATE WITH A SLIGHT LEAN TOWARDS BELOW-NORMAL TEMPERATURES FOR PARTS OF
SOUTHEASTERN ALASKA. BELOW-NORMAL PRECIPITATION IS FAVORED FOR MUCH OF ALASKA
DUE TO THE PREDICTED STORM TRACK WELL TO THE SOUTH.
THE DEEP 500-HPA TROUGH OVER THE NORTHEASTERN PACIFIC ALONG WITH A PERIOD OF
NORTHERLY SURFACE FLOW FAVORS BELOW-NORMAL TEMPERATURES THROUGHOUT HAWAII.
BASED ON THE CONSOLIDATION TOOL, NEAR NORMAL PRECIPITATION IS FORECAST ACROSS A
MAJORITY OF HAWAII EXCEPT FOR A SLIGHT LEAN TOWARDS DRY FOR THE NORTHWESTERN
ISLANDS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 30% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO
CONTINUED GOOD AGREEMENT AMONG THE PRECIPITATION TOOLS OFFSET BY DIFFERENCES
AMONG THE TEMPERATURE TOOLS ACROSS THE CENTRAL AND EASTERN CONUS.
FORECASTER: BRAD PUGH
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 1991-2020 BASE PERIOD MEANS AS REFERENCE IN
THE CLIMATE OUTLOOKS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON
FEBRUARY 15.
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:
19510220 - 19810222 - 19690222 - 20040201 - 19790127
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:
19510220 - 19690221 - 19810221 - 20050209 - 19550217
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR FEB 14 - 18 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A A NRN CALIF A A
SRN CALIF N A IDAHO A N NEVADA A A
W MONTANA B A E MONTANA B A WYOMING N A
UTAH A A ARIZONA N A COLORADO N A
NEW MEXICO N A N DAKOTA N A S DAKOTA N A
NEBRASKA N A KANSAS N A OKLAHOMA N A
N TEXAS B A S TEXAS B A W TEXAS N A
MINNESOTA A N IOWA A N MISSOURI N B
ARKANSAS B B LOUISIANA B A WISCONSIN A N
ILLINOIS N B MISSISSIPPI B B MICHIGAN N B
INDIANA N B OHIO B B KENTUCKY B B
TENNESSEE B B ALABAMA B N NEW YORK B B
VERMONT B B NEW HAMP B B MAINE B B
MASS B B CONN B B RHODE IS B B
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 A FL PENIN B A AK N SLOPE A B
AK ALEUTIAN A N AK WESTERN A B AK INT BSN A B
AK S INT A B AK SO COAST A B AK PNHDL N B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR FEB 16 - 22 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A A NRN CALIF A A
SRN CALIF N A IDAHO A A NEVADA A A
W MONTANA B A E MONTANA B A WYOMING B A
UTAH A A ARIZONA N A COLORADO B A
NEW MEXICO B A N DAKOTA B N S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA N N IOWA N N MISSOURI B N
ARKANSAS B N LOUISIANA B A WISCONSIN N B
ILLINOIS B B MISSISSIPPI B A MICHIGAN B B
INDIANA B B OHIO B B KENTUCKY B B
TENNESSEE B N ALABAMA B A NEW YORK B B
VERMONT B B NEW HAMP B B MAINE B B
MASS B B CONN B B RHODE IS B B
PENN B B NEW JERSEY B B W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B A S CAROLINA B A GEORGIA B A
FL PNHDL B A FL PENIN B A AK N SLOPE A B
AK ALEUTIAN A N AK WESTERN A B AK INT BSN A B
AK S INT A N AK SO COAST A N AK PNHDL B B
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.
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