581
FXUS06 KWBC 172002
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST WED JANUARY 17 2024
6-10 DAY OUTLOOK FOR JAN 23 - 27 2024
MODELS REMAIN IN VERY GOOD AGREEMENT TODAY SHOWING AN AMPLIFIED MID-LEVEL
PATTERN. A MEAN 500-HPA TROUGH AXIS EXTENDS SOUTHWARD THROUGH MAINLAND ALASKA,
WITH A CLOSED LOW OF ABOUT 519-DM CENTERED NEAR THE ALEUTIANS AND A DOWNSTREAM
MID-LEVEL RIDGE AXIS ACROSS WESTERN CANADA. FARTHER EAST, THERE IS A DEEP MEAN
TROUGH CENTERED OVER BAFFIN BAY WITH 500-HPA HEIGHTS BELOW 489-DM AND AN AXIS
EXTENDING SOUTHEASTWARD ACROSS SOUTHERN GREENLAND AND INTO THE NORTH ATLANTIC.
THE GEFS, EUROPEAN ENSEMBLE MEAN, AND CANADIAN ENSEMBLE MEAN ALL SHOW 500-HPA
HEIGHT ANOMALIES AVERAGING AT LEAST 30-DM BELOW NORMAL NEAR SOUTHERN GREENLAND.
TO THE SOUTH ACROSS THE MID-LATITUDES, A STRONG MEAN RIDGE COVERS MOST OF
CENTRAL AND SOUTHERN CANADA AND THE CONTIGUOUS U.S. (CONUS), WITH THE LARGEST
POSITIVE MEAN 500-HPA ANOMALIES CENTERED NEAR THE EASTERN GREAT LAKES AND
NORTHERN APPALACHIANS. THE GEFS AND THE EUROPEAN ENSEMBLE MEAN DEPICT 500-HPA
HEIGHT ANOMALIES APPROACHING +27-DM IN THIS REGION FOR THE 6 TO 10 DAY PERIOD
AS A WHOLE. SUBNORMAL 500-HPA HEIGHTS ARE RESTRICTED TO THE SOUTHERN ROCKIES
AND HIGH PLAINS ASSOCIATED WITH A LOWER-LATITUDE TROUGH WITH AN AXIS EXTENDING
SOUTHWARD TOWARD CENTRAL MEXICO.
WITH MOST OF THE CONUS UNDER OR JUST UPSTREAM FROM A FLAT 500-HPA RIDGE,
ABOVE-NORMAL TEMPERATURES ARE FAVORED THROUGHOUT THE CONUS. ODDS FOR
SIGNIFICANTLY ABOVE-NORMAL TEMPERATURES EXCEED 90 PERCENT OVER THE GREAT LAKES
REGION AND PARTS OF THE NORTHEAST, NEAR THE GREATEST 500-HPA HEIGHT DEPARTURES.
IN THE MEAN, ALL MODELS PLACE A SURFACE HIGH PRESSURE OFF THE EAST COAST, WITH
LOWER SURFACE PRESSURES IN THE SOUTHWEST NEAR THE MID-LEVEL LOWER-LATITUDE
TROUGH. THE EXPECTED PRESSURE GRADIENT WOULD CREATE A MILD AND MOIST FLOW
COMING INTO THE CONUS FROM THE GULF OF MEXICO AND ADJACENT SUB-TROPICS
NORTHWARD INTO A LARGE PART OF THE CONUS, THUS MOST OF THE CONUS HAS ENHANCED
CHANCES FOR ABOVE-NORMAL PRECIPITATION. THE STRONGEST INFLOW IS EXPECTED OVER
THE SOUTHERN PLAINS AND SOUTHEAST, DOWNSTREAM FROM THE MID-LEVEL TROUGH, AND
THE COMBINATION OF STRONG MOISTURE INFLUX AND FAVORABLE MID-LEVEL FLOW STRONGLY
ENHANCES THE LIKELIHOOD OF ABOVE-NORMAL PRECIPITATION IN THESE AREAS, WITH
CHANCES EXCEEDING 70 PERCENT. THE GEFS, EUROPEAN ENSEMBLE MEAN, AND CANADIAN
ENSEMBLE MEAN ALL SHOW 3 TO 5 INCHES OF PRECIPITATION FALLING ALONG AND NEAR
THE CENTRAL GULF COAST DURING THE 6- TO 10-DAY PERIOD. SUBNORMAL TOTALS ARE
FAVORED ONLY IN THE NORTHERN PLAINS AND ACROSS PARTS OF SOUTHWESTERN
CALIFORNIA, WHICH ARE FARTHEST AWAY FROM THE STRONG LOW-LEVEL MOISTURE INFLUX.
ALASKA WILL BE DOMINATED BY SOUTHEAST-TO-NORTHWEST LOWER AND MID-LEVEL FLOW
ACROSS THE STATE, WITH AN ARCTIC SURFACE HIGH OVER THE NORTHERN PART OF THE
STATE AND A MEAN SURFACE LOW PRESSURE NEAR THE MID-LEVEL TROUGH AXIS IN THE
GULF OF ALASKA. RELATIVE TO YESTERDAY, THE ARCTIC HIGH IS SLIGHTLY FARTHER
SOUTH AND THE NORTH PACIFIC SURFACE LOW FARTHER EAST CLOSER TO THE MAINLAND,
BUT THE EFFECT OF THESE CHANGES ON SENSIBLE WEATHER IS SUBTLE. THE ARCTIC HIGH
PRESSURE FAVORS BELOW NORMAL TEMPERATURES ACROSS MOST OF THE STATE EXCEPT IN
SOUTHEASTERN SECTIONS, WHERE LOW-LEVEL FLOW WILL BE FROM THE SOUTHEAST,
BRINGING IN RELATIVELY MOIST AND MILD AIR. THIS SET-UP ALSO FAVORS ABOVE-NORMAL
PRECIPITATION OVER SOUTHEASTERN ALASKA, BUT NOT REACHING AS FAR TO THE NORTH
AND WEST AS FORECAST YESTERDAY. FARTHER WEST, THE EAST-TO-WEST FETCH WILL BE
COMING ACROSS A LONG STRETCH OF LAND, FAVORING BELOW-NORMAL PRECIPITATION THERE.
MOST OF THE TOOLS FAVOR WETTER-THAN-NORMAL WEATHER ACROSS HAWAII, CONSISTENT
WITH RELATIVELY LOW 500-HPA HEIGHTS TO THE NORTH AND NORTHWEST OF THE STATE.
CONSOLIDATED TOOLS ARE NOT AS BULLISH WITH WARMTH IN NORTHWESTERN PARTS OF THE
ISLAND CHAIN AS THEY WERE YESTERDAY, SO TEMPERATURES CLOSER TO NORMAL ARE
FORECAST FOR THE 6- TO 10-DAY PERIOD.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S GFS
SUPERENSEMBLE MEAN CENTERED ON DAY 8, 30% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, 20% 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, GIVEN
UNUSUALLY GOOD AGREEMENT IN BOTH THE RAW MODEL OUTPUTS AND THE DERIVED
BIAS-CORRECTED AND REFORECAST TOOLS. GUIDANCE IS LEAST CONSISTENT IN DEPICTING
HOW FAR NORTHWEST ABOVE-NORMAL TEMPERATURES WILL EXTEND OUT OF SOUTHEASTERN
ALASKA.
8-14 DAY OUTLOOK FOR JAN 25 - 31 2024
FOR WEEK-2, THE DETAILS OF THE MODEL SOLUTIONS DO NOT AGREE QUITE AS WELL AS
DURING THE 6 TO 10 DAY PERIOD, AND MODEL CONSISTENCY DETERIORATES SIGNIFICANTLY
TOWARD THE END OF WEEK-2. MOST MODELS DEPICT A SIMILAR MEAN MID-LEVEL PATTERN,
HOWEVER, DRIVEN BY VERY GOOD AGREEMENT DURING THE FIRST HALF OF THE PERIOD.
THERE IS A STRONG MEAN MID-LEVEL TROUGH OVER BAFFIN BAY, GREENLAND, AND
SURROUNDING AREAS WHILE ABOVE-NORMAL 500-HPA HEIGHTS ARE FORECAST ACROSS MOST
OF THE CONUS AND CANADA. MODELS SHOW THE LARGEST POSITIVE 500-HPA HEIGHT
DEPARTURES SOMEWHERE FROM THE CANADIAN PRAIRIES TO THE NORTHEASTERN CONUS.
TELECONNECTIONS TO THE STRONG TROUGH NEAR GREENLAND FAVOR A POSITIVE ANOMALY
CENTER FARTHER EAST, WHICH IS CLOSER TO THE EUROPEAN ENSEMBLE MEAN, AND THIS
SOLUTION IS SLIGHTLY FAVORED AT THIS TIME. IN ANY CASE, ABOVE-NORMAL 500-HPA
HEIGHTS EXTEND WESTWARD ACROSS MOST OF CANADA AND THE NORTHERN TIER OF THE
CONUS TO A SECONDARY RIDGE AXIS BUILDING OVER MOST OF WESTERN NORTH AMERICA,
INCLUDING ALASKA. THIS IS A SIGNIFICANT CHANGE OVER AND NEAR ALASKA, WHERE THE
DEEP TROUGH DURING THE 6-10 DAY PERIOD IS EXPECTED TO DRIFT SOUTH AND
DEAMPLIFY, RESULTING IN A MEAN FLAT MID-LEVEL TROUGH ACROSS THE CENTRAL NORTH
PACIFIC OCEAN. MEANWHILE, A WEAKENING MID-LEVEL TROUGH PERSISTS IN THE
SOUTHWEST, WITH AN AXIS NEAR THE SOUTHERN PLAINS AND A SOMEWHAT POSITIVE TILT.
BY THE END OF WEEK-2, THERE ARE SOME SIGNIFICANT DIFFERENCES IN THE ENSEMBLE
MEANS. THE GEFS AND EUROPEAN ENSEMBLE MEANS SHOW A STRONG RIDGE OVER ALASKA
WHILE THE CANADIAN ENSEMBLE MEAN PLACES THE MID-LEVEL RIDGE CENTER FARTHER
NORTHWEST, AND WEAKER. FARTHER SOUTH, THE EUROPEAN AND CANADIAN ENSEMBLE MEANS
KEEP ABOVE-NORMAL 500-HPA HEIGHTS ACROSS THE WESTERN HALF OF THE CONUS WHILE
THE GEFS SHOWS NEAR-NORMAL HEIGHTS. ON DAY 14, THE CANADIAN ENSEMBLE MEAN KEEPS
A FAIRLY STRONG MID-LEVEL TROUGH OVER BAFFIN BAY WITH THE LARGEST NEGATIVE
500-HPA ANOMALIES NEAR SOUTHERN GREENLAND, WHILE THE GEFS KEEPS A VORTEX NEAR
THE SAME AREA BUT WITH HEIGHTS CLOSE TO NORMAL. THE BUILDING MID-LEVEL RIDGE IN
NORTHWESTERN NORTH AMERICA COULD PRESAGE A RENEWED OUTBREAK OF COLD AIR IN MUCH
OF THE CONUS BEYOND THE WEEK-2 PERIOD, BUT THERE IS A LOT OF UNCERTAINTY DUE TO
THE DISPARATE SOLUTIONS OF THE MODELS TOWARD THE END OF THE PERIOD.
THE PREVAILING ABOVE-NORMAL 500-HPA HEIGHTS IN THE MEAN WILL CONTINUE TO FAVOR
ABOVE-NORMAL TEMPERATURES THROUGHOUT THE CONUS, WITH THE GREATEST CHANCES OF
OCCURRENCE (OVER 70 PERCENT) ACROSS THE GREAT LAKES, OHIO VALLEY, MID-ATLANTIC,
AND SOUTHEASTERN CONUS IN ADDITION TO MUCH OF CALIFORNIA, WHICH WILL BE UNDER
THE INFLUENCE OF THE BUILDING MID-LEVEL RIDGE IN WESTERN NORTH AMERICA.
ABOVE-NORMAL PRECIPITATION IS ALSO FAVORED FOR MUCH OF THE CONUS, PARTICULARLY
ACROSS THE CENTRAL GULF COAST AND ADJACENT AREAS CLOSEST TO STRONG SURFACE
MOISTURE INFLUX AND DOWNSTREAM FROM THE LOW-LATITUDE MID-LEVEL TROUGH EARLY IN
THE PERIOD. WITH SURFACE PRESSURES RISING ACROSS THE INTERIOR WEST,
BELOW-NORMAL PRECIPITATION IS FAVORED FOR ROUGHLY THE SOUTHWESTERN QUARTER OF
THE COUNTRY WHILE ONSHORE NEAR-SURFACE FLOW BRINGS ENHANCED CHANCES FOR
ABOVE-NORMAL PRECIPITATION TO THE NORTHWEST.
WITH SURFACE HIGH PRESSURES DRIFTING SOUTHWARD IN MAINLAND ALASKA, SUBNORMAL
TEMPERATURES ARE FAVORED OVER MOST OF THE STATE OUTSIDE SOUTHEASTERN AREAS
(UNDER THE INFLUENCE OF SOUTHERLY SURFACE FLOW) AND THE NORTHERN TIER (UNDER
WESTERLY WINDS NORTH OF THE CORE OF THE ARCTIC HIGH PRESSURE). THE SOUTHERLY
WINDS IN SOUTHEASTERN PARTS OF THE STATE ENHANCE CHANCES FOR SURPLUS
PRECIPITATION IN THAT REGION WHILE COLD, DRY SURFACE AIR TRACKING ACROSS A LONG
STRETCH OF LAND INCREASES THE ODDS FOR SUBNORMAL PRECIPITATION IN THE WESTERN
PART OF THE STATE.
MOST OF THE TOOLS CONTINUE TO FAVOR WETTER-THAN-NORMAL WEATHER ACROSS HAWAII
DURING WEEK-2, CONSISTENT WITH RELATIVELY LOW 500-HPA HEIGHTS TO THE NORTH AND
NORTHWEST OF THE STATE. IN ADDITION, CONSOLIDATED TOOLS CONTINUE TO ADVERTISE
REDUCED CHANCES FOR ABOVE-NORMAL TEMPERATURES IN NORTHWESTERN PARTS OF THE
ISLAND CHAIN RELATIVE TO YESTERDAY.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 60% OF TODAY'S GFS
SUPERENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY'S OPERATIONAL 0Z GFS
CENTERED ON DAY 11, AND 25% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOVE NORMAL, 3 OUT OF 5, FOR GOOD
OVERALL MODEL AGREEMENT IN THE MEAN MID-LEVEL PATTERN, TEMPERED BY INCREASED
UNCERTAINTY IN THE DETAILS OF THE STRENGTH AND TIMING OF MID-LEVEL FEATURES,
AND DIVERGING MODEL SOLUTIONS LATE IN THE PERIOD.
FORECASTER: RICH TINKER
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
JANUARY 18.
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:
19960131 - 19681229 - 19590117 - 19800125 - 19700104
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:
19590117 - 19800125 - 19960130 - 19681229 - 19700105
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 23 - 27 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A A
SRN CALIF A N IDAHO A A NEVADA A A
W MONTANA A N E MONTANA A B WYOMING A N
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA A B S DAKOTA A B
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A A
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A N
MASS A A CONN A A RHODE IS A A
PENN A A NEW JERSEY A A W VIRGINIA A A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A A AK N SLOPE B N
AK ALEUTIAN B B AK WESTERN B B AK INT BSN B N
AK S INT B N AK SO COAST B B AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 25 - 31 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A B
SRN CALIF A B IDAHO A A NEVADA A B
W MONTANA A A E MONTANA A N WYOMING A N
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A N N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A A
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN A A NEW JERSEY A A W VIRGINIA A A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A A AK N SLOPE N N
AK ALEUTIAN B B AK WESTERN B B AK INT BSN B B
AK S INT B B AK SO COAST B B AK PNHDL N 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.
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