Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/30/16
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
246 PM PST THU JAN 28 2016
.SYNOPSIS...RAIN CHANCES WILL DEVELOP ACROSS THE NORTH BAY THIS
EVENING ...AND ACROSS THE REST OF THE SAN FRANCISCO BAY AREA BY
EARLY FRIDAY MORNING...AND INTO THE MONTEREY BAY AREA BY FRIDAY
EVENING. WET WEATHER THEN POSSIBLE INTO SUNDAY WITH A SLIGHT
CHANCE OF THUNDERSTORMS SUNDAY AFTERNOON. LOCALLY STRONG AND
GUSTY NORTHWEST WINDS EXPECTED SUNDAY AFTERNOON AND EVENING...
MAINLY NEAR THE COAST. DRY WEATHER RETURNS MONDAY.
&&
.DISCUSSION...AS OF 03:00 PM PST THURSDAY... KMUX RADAR PRESENTLY
DETECTING LIGHT RADAR RETURNS ACROSS THE SAN FRANCISCO AND
MONTEREY BAY REGIONS HOWEVER MOST REFLECTIVITIES ARE DUE TO
VIRGA. WHAT PRECIPITATION DOES OVERCOME TO ODDS AND MAKE IT TO
THE SURFACE THIS AFTERNOON WILL RANGE FROM A FEW RAIN DROPS IN
TOTAL TO A FEW HUNDREDTHS. GROUND OBSERVATIONS CONFIRM THIS AS
ONLY A HANDFUL OF SITES IN THE NORTH BAY HAVE REPORTED A FEW
HUNDREDTHS OF RAIN SO FAR. VISIBLE SATELLITE SHOWS STRATOCUMULUS
BELOW THE HIGHER CIRROSTRATUS DECK. THESE CLOUDS AND RADAR RETURNS
ARE ARRIVING AHEAD OF AN ADVANCING COLD FRONTAL BOUNDARY CURRENTLY
SLANTED FROM SPOKANE TO EUREKA AND PUSHING EAST-SOUTHEASTWARD.
SHORT TERM GUIDANCE MODELS CONTINUE TO SUGGEST MEASURABLE RAIN
WILL NOT BEGIN EN MASSE UNTIL AFTER 6PM FOR THE NORTH BAY BEFORE
SPREADING SLOWLY SPREADING MOSTLY EASTWARD OVERNIGHT.
PRECIPITATION IS NOT EXPECTED TO SPREAD INTO THE IMMEDIATE BAY
AREA UNTIL EARLY FRIDAY MORNING AS THE TRAJECTORY OF THE INITIAL
MOMENTUM IS HEADING EASTWARD RATHER THAN SOUTHWARD.
IN THE POST FRONTAL ENVIRONMENT... A RATHER MOIST WESTERLY
DIFFLUENT FLOW PATTERN WILL SET UP BY FRIDAY... WITH A TROPICAL
PRECIPITABLE WATER PLUME OF 1.15-1.35" AIMED OUT OUR FORECAST
AREA. THE PLUME WILL INITIALLY BE AIMED AT NORTH BAY ON
FRIDAY...THE IMMEDIATE BAY AREA FRIDAY NIGHT...AND THE MONTEREY
BAY AREA BY EARLY SATURDAY. UNFORTUNATELY... THIS FLOW IS DEVOID
OF A SIGNIFICANT LIFTING MECHANISM OUTSIDE OF THE ALWAYS PRESENT
TERRAIN INDUCED OROGRAPHIC EFFECTS. THUS... THE NEXT FEW DAYS WILL
BE CLOUDY AND SEE VERY LIGHT INTERMITTENT PRECIPITATION FOR LOWER
ELEVATION SITES AS MINOR UNMODELED DISTURBANCES TAP INTO THE
ATMOSPHERIC WATER SUPPLY ABOVE OUR HEADS. OROGRAPHIC EFFECTS WILL
LEAD TO LOCALLY HIGHER PRECIPITATION AMOUNTS FOR COASTAL RANGES
AND RIDGES... SUCH AS THE MARIN HEADLANDS... SANTA CRUZ
MOUNTAINS... AND BIG SUR.
BY SATURDAY AFTERNOON... A NARROW RIDGE OF HIGH PRESSURE
RAPIDLY AMPLIFIES IN THE GULF OF ALASKA WHICH WILL HELP TO
ORGANIZE A SERIES OF VORTICITY MAXIMA DOWNSTREAM. THIS NEWLY
ORGANIZED DISTURBANCE WILL MOVE INTO OUR AREA ON SATURDAY AND
BRING A POSSIBILITY OF THUNDERSTORMS BY SATURDAY AFTERNOON. THE
STRONGEST OF THESE VORTICITY MAX WILL TRAVERSE THROUGH THE
BACKSIDE OF THE NEWLY FORMED UPPER LOW AND LEAD TO A JET STREAK
ALONG THE IMMEDIATE COAST. THIS PATTERN IS TYPICALLY RATHER WINDY
AS THERE IS AN ADDITIVE EFFECT OF THE WIND ITSELF AS WELL AS THE
STORM MOMENTUM. ALONG THE COAST... BREEZY TO WINDY CONDITIONS ARE
WITHIN THE REALM OF POSSIBILITY FOR SUNDAY INTO EARLY MONDAY.
DRY WEATHER IS EXPECTED ON MONDAY INTO TUESDAY THEN A SLIGHT
CHANCE OF RAIN LOOMS FOR MIDWEEK NEXT WEEK. 240 HOUR MODEL RUNS
HAVE ALIGNED FOR THE FIRST TIME AND SHOW DRY WEATHER FOR NEXT
SUNDAY.
&&
.AVIATION...AS OF 9:30 AM PST THURSDAY...VFR TODAY. TAFS WERE ALL
ADJUSTED TO DELAY THE ONSET OF RAIN BASED OFF LATEST HRRR AND NAM
MODELS. NOW LOOKS LIKE -RA GENERALLY STAYS OUT OF THE AREA UNTIL
12Z (WHICH MAY BE OPTIMISTIC). COMBINATION OF -SHRA AND -RA FOR
TOMORROW. MODERATE CONFIDENCE.
VICINITY OF KSFO...VFR IS EXPECTED TO PREVAIL TODAY WITH LIGHT
VARIABLE WINDS BECOMING WESTERLY WITH THE AFTERNOON SEA BREEZE.
-SHRA BY OR AFTER 12Z. HIGH CONFIDENCE THROUGH 06Z.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR IS EXPECTED TO PREVAIL TODAY
WITH GENERALLY LIGHT WINDS BECOMING WESTERLY WITH THE AFTERNOON
SEA BREEZE. -SHRA AND -RA LIKELY DELAYED TO AFTER THE FORECAST
WINDOW. HIGH CONFIDENCE.
&&
.MARINE...AS OF 09:30 AM PST THURSDAY...LOOK FOR FAIRLY LIGHT
WINDS TO CONTINUE THROUGH FRIDAY NIGHT. A MODERATE WEST SWELL WILL
BUILD TODAY WITH FAST MOVING FORERUNNER WAVES ARRIVING LATE THIS
MORNING. THIS ENERGETIC AND BUILDING SWELL WILL RESULT IN LARGE
BREAKING WAVES AT OFFSHORE REEFS AND SAND BARS ALONG THE COAST.
THESE CONDITIONS WILL PERSIST THROUGH AT LEAST FRIDAY AFTERNOON.
THE SEA STATE WILL DETERIORATE SUNDAY AND MONDAY AS WINDS INCREASE
OUT OF THE NORTH.
&&
.BEACHES...AS OF 10:15 AM PST THURSDAY... WESTERLY SWELL WILL BUILD
THROUGHOUT THE DAY TODAY WITH ENERGETIC FORERUNNER WAVES ARRIVING
THIS MORNING. THE LARGEST WAVES WILL BEGIN TO MOVE INTO THE SURF
ZONE LATER THIS AFTERNOON...PERSISTING INTO EARLY SATURDAY MORNING.
EXCESSIVE WAVE RUN UP IS EXPECTED WITH THESE WAVES WITH LONG LULLS
BETWEEN WAVE SETS...INCREASING THE RISK OF BEING WASHED OFF OF THE
BEACH BY SNEAKER WAVES. LARGE SURF IS EXPECTED WITH THESE WAVES AS
WELL AS STRONG RIP CURRENTS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...HIGH SURF ADVISORY...ENTIRE COASTLINE SONOMA TO BIG SUR
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: DRP
AVIATION: BELL
MARINE: BELL
BEACHES: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1021 AM PST THU JAN 28 2016
.SYNOPSIS...HIGH PRESSURE ALOFT WILL MAINTAIN DRY WEATHER
CONDITIONS AND MILD TEMPERATURES OVER THE AREA THROUGH MOST OF
TODAY. RAIN CHANCES WILL DEVELOP ACROSS THE NORTH BAY LATER IN THE
DAY...AND ACROSS THE REST OF THE SAN FRANCISCO BAY AREA BY LATE
FRIDAY...AND INTO THE MONTEREY BAY AREA BY FRIDAY EVENING.
PRECIPITATION CHANCES WILL DECREASE ON SATURDAY AND THEN INCREASE
ONCE AGAIN ON SATURDAY NIGHT...BUT MAINLY ACROSS THE SOUTHERN
COUNTIES. WINDS WILL BE LIGHT TO MODERATE THROUGH EARLY
SUNDAY...WITH LOCALLY STRONG AND GUSTY NORTHWEST WINDS EXPECTED
SUNDAY AFTERNOON AND EVENING...MAINLY NEAR THE COAST.
&&
.DISCUSSION...AS OF 10:15 AM PST THURSDAY... HIGH CLOUDS PRECEEDING
AN ADVANCING COLD FRONTAL BOUNDARY HAVE SPREAD ACROSS THE ENTIRE
FORECAST AREA THIS MORNING. THIS COLD FRONTAL BOUNDARY IS
CURRENTLY DRAPED FROM JUST INLAND OF THE PACIFIC NORTHWEST
COASTLINE SOUTHWARD TO THE IMMEDIATE OREGON/CALIFORNIA
COASTLINE... AND JUST OFFSHORE OF THE NORTHERN CALIFORNIA COAST.
RADAR IMAGERY IS PICKING UP LIGHT REFLECTIVITY RETURNS OVER
NORTHERN CALIFORNIA FROM MENDOCINO COUNTY NORTHWARD AHEAD OF THE
FRONT AT THIS TIME. RADAR IS ALSO PICKING UP SOME MARGINAL
REFLECTIVITES OF 15DBZ OR LESS OVER PORTIONS OF THE BAY AREA...
HOWEVER IT IS VERY UNLIKELY THAT PRECIPITATION IS MAKING IT TO
THE SURFACE. LATEST SHORT TERM GUIDANCE MODELS SUGGEST MEASURABLE
RAIN WILL NOT BEGIN EN MASSE UNTIL THIS EVENING FOR THE NORTH BAY
BEFORE SPREADING SLOWLY SPREADING MOSTLY EASTWARD OVERNIGHT.
PRECIPITATION IS NOT EXPECTED TO SPREAD INTO THE IMMEDIATE BAY
AREA UNTIL EARLY FRIDAY MORNING AS THE TRAJECTORY OF THE INITIAL
MOMENTUM IS HEADING EASTWARD RATHER THAN SOUTHWARD.
IN THE POST FRONTAL ENVIRONMENT... A RATHER MOIST WESTERLY
DIFFLUENT FLOW PATTERN WILL SET UP BY FRIDAY... WITH A TROPICAL
PRECIPITABLE WATER PLUME OF 1.15-1.35" AIMED OUT OUR FORECAST
AREA. THE PLUME WILL INITIALLY BE AIMED AT NORTH BAY ON
FRIDAY...THE IMMEDIATE BAY AREA FRIDAY NIGHT...AND THE MONTEREY
BAY AREA BY EARLY SATURDAY. UNFORTUNATELY... THIS FLOW IS DEVOID
OF A SIGNIFICANT LIFTING MECHANISM OUTSIDE OF THE ALWAYS PRESENT
TERRAIN INDUCED OROGRAPHIC EFFECTS. THUS... THE NEXT FEW DAYS WILL
BE CLOUDY AND SEE VERY LIGHT INTERMITTENT PRECIPITATION FOR LOWER
ELEVATION SITES AS MINOR UNMODELED DISTURBANCES TAP INTO THE
ATMOSPHERIC WATER SUPPLY ABOVE OUR HEADS. OROGRAPHIC EFFECTS WILL
LEAD TO LOCALLY HIGHER PRECIPITATION AMOUNTS FOR COASTAL RANGES
AND RIDGES... SUCH AS THE MARIN HEADLANDS... SANTA CRUZ
MOUNTAINS... AND BIG SUR.
BY SATURDAY AFTERNOON... A NARROW RIDGE OF HIGH PRESSURE
RAPIDLY AMPLIFIES IN THE GULF OF ALASKA WHICH WILL HELP TO
ORGANIZE A SERIES OF VORTICITY MAXIMA DOWNSTREAM. THIS NEWLY
ORGANIZED DISTURBANCE WILL MOVE INTO OUR AREA ON SATURDAY AND
BRING A POSSIBILITY OF THUNDERSTORMS BY SATURDAY AFTERNOON. THE
STRONGEST OF THESE VORTICITY MAX WILL TRAVERSE THROUGH THE
BACKSIDE OF THE NEWLY FORMED UPPER LOW AND LEAD TO A JET STREAK
ALONG THE IMMEDIATE COAST. THIS PATTERN IS TYPICALLY RATHER WINDY
AS THERE IS AN ADDITIVE EFFECT OF THE WIND ITSELF AS WELL AS THE
STORM MOMENTUM. ALONG THE COAST... BREEZY TO WINDY CONDITIONS ARE
WITHIN THE REALM OF POSSIBILITY FOR SUNDAY INTO EARLY MONDAY.
NO FORECAST UPDATES ARE ANTICIPATED UNTIL THE AFTERNOON FORECAST
PACKAGE IS ISSUED.
.PREVIOUS DISCUSSION...AS OF 2:42 AM PST THURSDAY...SATELLITE
SHOWS INCREASING MID AND HIGH CLOUDS MOVING OVER THE NORTH BAY
FROM THE NORTHWEST. THESE ARE ASSOCIATED WITH THE SOUTHERN EDGE OF
AN APPROACHING FRONTAL BOUNDARY...NOW FOCUSING ON THE PACIFIC
NORTHWEST. THIS FRONTAL BOUNDARY AND MOISTURE PLUME ARE FORECAST
TO GRADUALLY APPROACH OUR AREA OVER THE NEXT 24 HOURS.
HIGH PRESSURE ALOFT WILL KEEP MOST OF THE AREA DRY TODAY...WITH
THE PRECIPITATION ASSOCIATED WITH THE FRONTAL BOUNDARY SLOWLY
SAGGING SOUTH INTO THE NORTH BAY COUNTIES BY THIS AFTERNOON OR
EVENING. RAINFALL IS EXPECTED TO MOSTLY REMAIN CONFINED TO THE
NORTH BAY THROUGH TONIGHT. THE FRONTAL BOUNDARY IS THEN EXPECTED
TO PUSH SOUTH THROUGH THE REST OF THE SF BAY AREA AND INTO THE
MONTEREY BAY AREA BY LATE FRIDAY AND INTO FRIDAY NIGHT.
PRECIPITATION THROUGH FRIDAY NIGHT IS FORECAST TO BE
LIGHT...EXCEPT IN OROGRAPHICALLY-FAVORED REGIONS OF THE NORTH BAY
WHERE MODERATE AMOUNTS OF RAINFALL ARE EXPECTED.
A MOIST ZONAL FLOW WILL CONTINUE ACROSS NORTHERN AND CENTRAL
CALIFORNIA ON SATURDAY...BUT FORCING IS EXPECTED TO BE WEAK THAT
DAY. THUS...MOST AREAS WILL PROBABLY BE RELATIVELY DRY DURING THE
DAY SATURDAY.
THE UPPER TROUGH WILL BEGIN TO DROP IN FROM THE NORTHWEST LATE
SATURDAY. THERE CONTINUES TO BE DIFFERENCES IN THE MODEL OUTPUT
CONCERNING HOW MUCH RAINFALL WILL OCCUR WITH THIS SYSTEM AS IT
MOVES THROUGH THE AREA. THE 00Z GFS BRING WIDESPREAD RAINFALL
ACROSS ONLY THE SOUTHERN PORTION OF OUR AREA ON SATURDAY NIGHT AND
SUNDAY MORNING...MAINLY FROM MONTEREY BAY SOUTH. THE 00Z NAM ALSO
FORECASTS RENEWED RAINFALL ON SATURDAY NIGHT...BUT PLACES THE RAIN
FARTHER NORTH...BASICALLY ACROSS ALL AREAS SOUTH OF THE GOLDEN
GATE. NOW...THE 00Z ECMWF CONTINUES EARLIER TRENDS OF BRINGING
MUCH LESS PRECIP TO THE AREA AS THIS TROUGH MOVES THROUGH.
RAINFALL TOTALS THROUGH SUNDAY ARE FORECAST TO RANGE FROM 0.5" TO
1.5" IN THE NORTH BAY...WITH LOCALLY UP TO 2 INCHES IN THE
MOUNTAINS OF SONOMA COUNTY. SOUTH OF THE GOLDEN GATE RAINFALL
TOTALS ARE FORECAST TO RANGE ANYWHERE FROM A TENTH OF AN INCH TO
UP TO AN INCH. SCATTERED SHOWERS WILL LIKELY CONTINUE INTO
SUNDAY AFTERNOON AND MOSTLY END BY SUNDAY NIGHT.
WINDS ARE EXPECTED TO BE LIGHT TO MODERATE THROUGH MIDDAY
SUNDAY...BUT THEN PICK UP FROM THE NORTHWEST AFTER THE UPPER
TROUGH AXIS MOVES THROUGH AROUND MIDDAY SUNDAY. LOCALLY STRONG
AND GUSTY NORTHWEST WINDS ARE THEN EXPECTED TO OCCUR SUNDAY
AFTERNOON AND EVENING...MAINLY NEAR THE COAST.
MONDAY CURRENTLY LOOKS LIKE A DRY DAY. BEYOND MONDAY THE GENERAL
IDEA IS FOR CONTINUE UNSETTLED CONDITIONS WITH PERIODS OF
RAIN...BUT THE SPECIFICS ON TIMING AND RAINFALL INTENSITY ARE
DIFFICULT TO PIN DOWN DUE TO MODEL DIFFERENCES.
&&
.AVIATION...AS OF 9:30 AM PST THURSDAY...VFR TODAY. TAFS WERE ALL
ADJUSTED TO DELAY THE ONSET OF RAIN BASED OFF LATEST HRRR AND NAM
MODELS. NOW LOOKS LIKE -RA GENERALLY STAYS OUT OF THE AREA UNTIL
12Z (WHICH MAY BE OPTIMISTIC). COMBINATION OF -SHRA AND -RA FOR
TOMORROW. MODERATE CONFIDENCE.
VICINITY OF KSFO...VFR IS EXPECTED TO PREVAIL TODAY WITH LIGHT
VARIABLE WINDS BECOMING WESTERLY WITH THE AFTERNOON SEA BREEZE.
-SHRA BY OR AFTER 12Z. HIGH CONFIDENCE THROUGH 06Z.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR IS EXPECTED TO PREVAIL TODAY
WITH GENERALLY LIGHT WINDS BECOMING WESTERLY WITH THE AFTERNOON
SEA BREEZE. -SHRA AND -RA LIKELY DELAYED TO AFTER THE FORECAST
WINDOW. HIGH CONFIDENCE.
&&
.MARINE...AS OF 09:30 AM PST THURSDAY...LOOK FOR FAIRLY LIGHT
WINDS TO CONTINUE THROUGH FRIDAY NIGHT. A MODERATE WEST SWELL WILL
BUILD TODAY WITH FAST MOVING FORERUNNER WAVES ARRIVING LATE THIS
MORNING. THIS ENERGETIC AND BUILDING SWELL WILL RESULT IN LARGE
BREAKING WAVES AT OFFSHORE REEFS AND SAND BARS ALONG THE COAST.
THESE CONDITIONS WILL PERSIST THROUGH AT LEAST FRIDAY AFTERNOON.
THE SEA STATE WILL DETERIORATE SUNDAY AND MONDAY AS WINDS INCREASE
OUT OF THE NORTH.
&&
.BEACHES...AS OF 10:15 AM PST THURSDAY... WESTERLY SWELL WILL BUILD
THROUGHOUT THE DAY TODAY WITH ENERGETIC FORERUNNER WAVES ARRIVING
THIS MORNING. THE LARGEST WAVES WILL BEGIN TO MOVE INTO THE SURF
ZONE LATER THIS AFTERNOON...PERSISTING INTO EARLY SATURDAY MORNING.
EXCESSIVE WAVE RUN UP IS EXPECTED WITH THESE WAVES WITH LONG LULLS
BETWEEN WAVE SETS...INCREASING THE RISK OF BEING WASHED OFF OF THE
BEACH BY SNEAKER WAVES. LARGE SURF IS EXPECTED WITH THESE WAVES AS
WELL AS STRONG RIP CURRENTS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ENTIRE COASTLINE FROM 4PM
SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 4 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 4 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 4 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 10 AM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 4 PM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 4 PM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: DRP
AVIATION: BELL
MARINE: BELL
BEACHES: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
932 AM PST THU JAN 28 2016
.SYNOPSIS...HIGH PRESSURE ALOFT WILL MAINTAIN DRY WEATHER
CONDITIONS AND MILD TEMPERATURES OVER THE AREA THROUGH MOST OF
TODAY. RAIN CHANCES WILL DEVELOP ACROSS THE NORTH BAY LATER IN THE
DAY...AND ACROSS THE REST OF THE SAN FRANCISCO BAY AREA BY LATE
FRIDAY...AND INTO THE MONTEREY BAY AREA BY FRIDAY EVENING.
PRECIPITATION CHANCES WILL DECREASE ON SATURDAY AND THEN INCREASE
ONCE AGAIN ON SATURDAY NIGHT...BUT MAINLY ACROSS THE SOUTHERN
COUNTIES. WINDS WILL BE LIGHT TO MODERATE THROUGH EARLY
SUNDAY...WITH LOCALLY STRONG AND GUSTY NORTHWEST WINDS EXPECTED
SUNDAY AFTERNOON AND EVENING...MAINLY NEAR THE COAST.
&&
.DISCUSSION...AS OF 2:42 AM PST THURSDAY...SATELLITE SHOWS
INCREASING MID AND HIGH CLOUDS MOVING OVER THE NORTH BAY FROM THE
NORTHWEST. THESE ARE ASSOCIATED WITH THE SOUTHERN EDGE OF AN
APPROACHING FRONTAL BOUNDARY...NOW FOCUSING ON THE PACIFIC
NORTHWEST. THIS FRONTAL BOUNDARY AND MOISTURE PLUME ARE FORECAST
TO GRADUALLY APPROACH OUR AREA OVER THE NEXT 24 HOURS.
HIGH PRESSURE ALOFT WILL KEEP MOST OF THE AREA DRY TODAY...WITH
THE PRECIPITATION ASSOCIATED WITH THE FRONTAL BOUNDARY SLOWLY
SAGGING SOUTH INTO THE NORTH BAY COUNTIES BY THIS AFTERNOON OR
EVENING. RAINFALL IS EXPECTED TO MOSTLY REMAIN CONFINED TO THE
NORTH BAY THROUGH TONIGHT. THE FRONTAL BOUNDARY IS THEN EXPECTED
TO PUSH SOUTH THROUGH THE REST OF THE SF BAY AREA AND INTO THE
MONTEREY BAY AREA BY LATE FRIDAY AND INTO FRIDAY NIGHT.
PRECIPITATION THROUGH FRIDAY NIGHT IS FORECAST TO BE
LIGHT...EXCEPT IN OROGRAPHICALLY-FAVORED REGIONS OF THE NORTH BAY
WHERE MODERATE AMOUNTS OF RAINFALL ARE EXPECTED.
A MOIST ZONAL FLOW WILL CONTINUE ACROSS NORTHERN AND CENTRAL
CALIFORNIA ON SATURDAY...BUT FORCING IS EXPECTED TO BE WEAK THAT
DAY. THUS...MOST AREAS WILL PROBABLY BE RELATIVELY DRY DURING THE
DAY SATURDAY.
THE UPPER TROUGH WILL BEGIN TO DROP IN FROM THE NORTHWEST LATE
SATURDAY. THERE CONTINUES TO BE DIFFERENCES IN THE MODEL OUTPUT
CONCERNING HOW MUCH RAINFALL WILL OCCUR WITH THIS SYSTEM AS IT
MOVES THROUGH THE AREA. THE 00Z GFS BRING WIDESPREAD RAINFALL
ACROSS ONLY THE SOUTHERN PORTION OF OUR AREA ON SATURDAY NIGHT AND
SUNDAY MORNING...MAINLY FROM MONTEREY BAY SOUTH. THE 00Z NAM ALSO
FORECASTS RENEWED RAINFALL ON SATURDAY NIGHT...BUT PLACES THE RAIN
FARTHER NORTH...BASICALLY ACROSS ALL AREAS SOUTH OF THE GOLDEN
GATE. NOW...THE 00Z ECMWF CONTINUES EARLIER TRENDS OF BRINGING
MUCH LESS PRECIP TO THE AREA AS THIS TROUGH MOVES THROUGH.
RAINFALL TOTALS THROUGH SUNDAY ARE FORECAST TO RANGE FROM 0.5" TO
1.5" IN THE NORTH BAY...WITH LOCALLY UP TO 2 INCHES IN THE
MOUNTAINS OF SONOMA COUNTY. SOUTH OF THE GOLDEN GATE RAINFALL
TOTALS ARE FORECAST TO RANGE ANYWHERE FROM A TENTH OF AN INCH TO
UP TO AN INCH. SCATTERED SHOWERS WILL LIKELY CONTINUE INTO
SUNDAY AFTERNOON AND MOSTLY END BY SUNDAY NIGHT.
WINDS ARE EXPECTED TO BE LIGHT TO MODERATE THROUGH MIDDAY
SUNDAY...BUT THEN PICK UP FROM THE NORTHWEST AFTER THE UPPER
TROUGH AXIS MOVES THROUGH AROUND MIDDAY SUNDAY. LOCALLY STRONG
AND GUSTY NORTHWEST WINDS ARE THEN EXPECTED TO OCCUR SUNDAY
AFTERNOON AND EVENING...MAINLY NEAR THE COAST.
MONDAY CURRENTLY LOOKS LIKE A DRY DAY. BEYOND MONDAY THE GENERAL
IDEA IS FOR CONTINUE UNSETTLED CONDITIONS WITH PERIODS OF
RAIN...BUT THE SPECIFICS ON TIMING AND RAINFALL INTENSITY ARE
DIFFICULT TO PIN DOWN DUE TO MODEL DIFFERENCES.
&&
.AVIATION...AS OF 9:30 AM PST THURSDAY...VFR TODAY. TAFS WERE ALL
ADJUSTED TO DELAY THE ONSET OF RAIN BASED OFF LATEST HRRR AND NAM
MODELS. NOW LOOKS LIKE -RA GENERALLY STAYS OUT OF THE AREA UNTIL
12Z (WHICH MAY BE OPTIMISTIC). COMBINATION OF -SHRA AND -RA FOR
TOMORROW. MODERATE CONFIDENCE.
VICINITY OF KSFO...VFR IS EXPECTED TO PREVAIL TODAY WITH LIGHT
VARIABLE WINDS BECOMING WESTERLY WITH THE AFTERNOON SEA BREEZE.
-SHRA BY OR AFTER 12Z. HIGH CONFIDENCE THROUGH 06Z.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR IS EXPECTED TO PREVAIL TODAY
WITH GENERALLY LIGHT WINDS BECOMING WESTERLY WITH THE AFTERNOON
SEA BREEZE. -SHRA AND -RA LIKELY DELAYED TO AFTER THE FORECAST
WINDOW. HIGH CONFIDENCE.
&&
.MARINE...AS OF 09:30 AM PST THURSDAY...LOOK FOR FAIRLY LIGHT
WINDS TO CONTINUE THROUGH FRIDAY NIGHT. A MODERATE WEST SWELL WILL
BUILD TODAY WITH FAST MOVING FORERUNNER WAVES ARRIVING LATE THIS
MORNING. THIS ENERGETIC AND BUILDING SWELL WILL RESULT IN LARGE
BREAKING WAVES AT OFFSHORE REEFS AND SAND BARS ALONG THE COAST.
THESE CONDITIONS WILL PERSIST THROUGH AT LEAST FRIDAY AFTERNOON.
THE SEA STATE WILL DETERIORATE SUNDAY AND MONDAY AS WINDS INCREASE
OUT OF THE NORTH.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ALL COASTAL LOCATIONS FROM 4 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 4 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 4 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 4 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 10 AM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 4 PM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 4 PM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: SIMS
AVIATION: BELL
MARINE: BELL
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
419 PM EST THU JAN 28 2016
.SYNOPSIS...
21Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFIED UPPER LEVEL
PATTERN IN PLACE ACROSS THE CONUS LATE THIS AFTERNOON. NORTHERN
STREAM FLOW FORMS A LARGE RIDGE OVER THE INTER-MOUNTAIN WEST INTO
WESTERN CANADA BEFORE DIVING BACK TO THE SOUTHEAST AND CARVING OUT
A LONGWAVE TROUGH THROUGH THE CENTRAL/EASTERN CONUS. A STRONG
SOUTHERN STREAM SHORTWAVE IS BEGINNING TO PHASE WITH THE NORTHERN
STREAM TROUGH/ENERGY ACROSS THE CENTRAL GULF...AND THIS WILL HELP
TO ACCELERATE THIS ENERGY EASTWARD AND OVER THE FLORIDA PENINSULA
DURING THE NEXT 12-18 HOURS. WHY IS THIS GOOD NEWS FOR OUR
FORECAST BEYOND THIS EVENING? WELL...INITIALLY AHEAD OF THIS
SHORTWAVE PASSAGE...WE WILL STILL BE DEALING WITH LOTS OF
RAIN/ISOLATED STORMS ACROSS THE REGION. HOWEVER...ONCE THIS ENERGY
PASSES TO OUR EAST...THIS WET PATTERN THAT HAS BEEN WITH US FOR
SEVERAL DAYS WILL COME TO AN ABRUPT END...AND RESULT IN A PERIOD
OF VERY PLEASANT WEATHER FOR FRIDAY AND THE UPCOMING WEEKEND. WE
ARE ALMOST THERE EVERYONE.
TROUGH AXIS IS VERY EVIDENT ON WV IMAGERY PUSHING ACROSS THE
CENTRAL GULF OF MEXICO...WITH A DRAMATIC AND SHARP BACK EDGE TO
THE DEEP MID/UPPER LEVEL MOISTURE PASSING EAST OF THE MS DELTA AS
OF 4 PM EST. A POWERFUL 160+ KNOT SOUTHERN STREAM JET IS CURRENTLY
ROUNDING THE BASE OF THIS TROUGH THROUGH THE SOUTHERN GULF AND
THEN MOVING DIRECTLY OVERHEAD OF THE FLORIDA PENINSULA. THE
ABUNDANT COLUMN MOISTURE AHEAD OF THE TROUGH IS SEEN RAPIDLY
ADVECTING TO THE NORTHEAST ACROSS OUR AREA WITHIN THIS STRONG
UPPER FLOW. HEIGHT FALLS ON THE EASTERN SIDE OF THE TROUGH ARE
CURRENTLY OVERSPREADING OUR FORECAST AREA UNDERNEATH DIFFLUENT
FLOW ALOFT. THE GFS/ECMWF BOTH SHOW THAT THE BEST DEEP LAYER
SYNOPTIC FORCING/QVECTOR CONVERGENCE IS RIGHT NOW PASSING THROUGH
OUR REGION LATE...AND WILL BE EXITING TO THE EAST AFTER 00Z. IT IS
THIS FORCING THAT IS RESULTING IN THE WIDESPREAD RAINFALL SEEN
MOVING IN FROM THE GULF OF MEXICO ON REGIONAL RADAR IMAGERY.
AT THE SURFACE...WHAT HAS BECOME A RATHER SHARP TROUGH ACROSS THE
EASTERN GULF OF MEXICO IS FORECAST EARLY THIS EVENING TO ACTUALLY
CLOSE OFF INTO A WEAK LOW AS IT CROSSES THE FL WEST COAST. SOME
INDICATION THAT THIS HAS ALREADY HAPPENED. THIS LOW/TROUGH AXIS
WILL NOW QUICKLY LIFT OFF TO THE EAST AND NORTHEAST AHEAD OF THE
APPROACHING TROUGH AXIS. THE TROUGH AXIS WHICH HAS BEEN QUASI-
STATIONARY FOR THE PAST 24 HOURS OR SO...IS NOW TRANSITIONING INTO
A COLD FRONT...WITH GFS/NAM SHOWING DECENT FGEN FIELDS CROSSING
THE PENINSULA DURING THE NEXT SEVERAL HOURS. THE LOW LEVEL
AGEOSTROPIC CIRCULATIONS WITH THIS FGEN BANDS ARE ONLY FURTHER
ENHANCING THE BROAD UPWARD SYNOPTIC MOTION...AND LIKELY WILL
RESULT IN A FEW BANDS OF HEAVY RAINFALL THROUGH 00Z.
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
FORECAST WILL FEATURE 100% POPS FOR ALL ZONES FOR THE NEXT
SEVERAL HOURS AS THE COLD FRONT STEADY DROPS THROUGH THE REGION.
FLOOD WATCH REMAINS IN EFFECT FOR OUR FAR SOUTHERN/SOUTH-INTERIOR
ZONES FOR A FEW MORE HOURS. THESE ZONES HAVE SEEN THE HEAVIEST
RAIN DURING THE PREVIOUS 48 HOURS...AND HAVE THE POTENTIAL TO SEE
SOME ADDITIONAL HEAVY RAINFALL THROUGH THE MID-EVENING HOURS.
HIGHLY SATURATED GROUNDS WILL MAKE IT EASIER FOR LOCALIZED
FLOODING OF STREETS AND LOW LYING AREA ACROSS THE WATCH AREA
SHOULD ANY HEAVIER BANDING WORK ACROSS THE AREA. THE GOOD NEWS FOR
THIS AREA IS THAT THE RAIN WILL BE ENDING QUICKLY LATER THIS
EVENING...ENTERING INTO AN EXTENDED PERIOD OF DRY WEATHER TO ALLOW
THE GROUND TO DRY OUT AND RECOVER.
AFTER 00Z...RAIN CHANCES WILL BEGIN TO TAPER OFF FROM WEST TO EAST
AS THE LOW LEVEL FRONT AND THE DEEP LAYER SYNOPTIC FORCING
ASSOCIATED WITH THE UPPER TROUGH PIVOT EASTWARD FROM OUR REGION.
HAVE REMOVED RAIN CHANCES FROM MOST ZONES AFTER 03Z...AND EVEN ALL
INTERIOR SOUTHERN ZONES AFTER MIDNIGHT. MAY TAKE LONGER TO BEGIN
TO REALLY CLEAR OUR SKIES OUT OF CLOUDS THOUGH. THE UPPER LEVELS
WILL DRY OUT IN A BIG HURRY BEHIND THE TROUGH AS DEEP LAYER
SUBSIDENCE OVERSPREAD THE PENINSULA. HOWEVER...THIS SETUP OF LARGE
SCALE SUBSIDENCE OVER-TOP RESIDUAL LOW LEVEL MOISTURE IS USUALLY A
GOOD SETUP FOR THE DEVELOPMENT OF LOWER STRATUS AT NIGHT. THIS
LOWER CLOUD COVER MAY BE WITH US THROUGH MUCH OF THE PRE-DAWN
HOURS...BUT SHOULD REALLY ONLY BE A CONCERN TO THE AVIATION
COMMUNITY. EVEN THESE LOWER STRATUS SHOULD BE BREAKING UP TOWARD
DAWN...AND AM FORECASTING PLENTY OF SUNSHINE FOR FRIDAY. THE SUN
IS LIKELY TO BE FILTERED AT TIMES THROUGH HIGH CIRRUS OVER THE
SOUTHERN ZONES WHERE THE STRONG SOUTHERN STREAM JET WILL STILL BE
PRESENT...BUT OVERALL THE FORECAST WILL BE FOR PARTLY TO MOSTLY
SUNNY SKIES.
AREAS OF DENSE MARINE FOG OVER TAMPA BAY AND THE SURROUNDING
COASTAL WATERS IS EXPECTED TO LINGER FOR A FEW MORE HOURS AS WE
AWAIT THE FRONTAL PASSAGE...BUT SHOULD SEE VISIBILITIES IMPROVE
OVER THESE MARINE WATERS ONCE THE WINDS SHIFT NORTHEAST AND SOME
SLIGHTLY DRIER AIR BEGINS ADVECTING IN. HAVE EXTENDED THE DENSE
FOG ADVISORY FOR THESE MARINE ZONES UNTIL 00Z...BUT DO NOT
ANTICIPATE ANY FURTHER EXTENSIONS OF THIS HAZARD.
COOLER TEMPS WILL BE FILTERING INTO THE REGION OVERNIGHT...WITH
READINGS BY SUNRISE RANGING FROM THE LOWER/MID 40S NORTH OF THE
I-4 CORRIDOR...TO GENERALLY BETWEEN 48 AND 54 FURTHER TO THE
SOUTH. HIGH TEMPERATURES FRIDAY AFTERNOON REACH THE LOWER/MIDDLE
60S.
THE COLDEST NIGHT AHEAD WILL BE FRIDAY NIGHT INTO EARLY SATURDAY
MORNING. WIDESPREAD LOW/MID 40S ARE IN THE FORECAST...WITH LIKELY
SOME SPOTS ACROSS THE NATURE COAST DROPPING INTO THE UPPER 30S.
A VERY PLEASANT DAY UNDER THE CONTROL OF HIGH PRESSURE IS ON TAP
FOR SATURDAY. FORECAST WILL HIGHLIGHT PLENTY OF SUN...LIGHT
WINDS...AND TEMPS RAPIDLY RECOVERING FROM THE COLDER EARLY MORNING
READINGS TO THE UPPER 60S/LOWER 70S IN THE AFTERNOON.
&&
.MID/LONG TERM (FRIDAY NIGHT-THURSDAY)... MODELS IN GOOD AGREEMENT
WITH PROGRESSIVE EL NINO PATTERN CONTINUING. ZONAL FLOW ALOFT
SATURDAY THEN UPPER RIDGING BUILDS IN THE WESTERN ATLANTIC IN
RESPONSE TO NEXT SOUTHERN STREAM TROUGH MOVING INTO THE DESERT SW
SUNDAY. SURFACE HIGH PRESSURE SETTLES OVER THE REGION SATURDAY THEN
MOVES INTO THE WESTERN ATLANTIC SUNDAY PRODUCING DRY AND SEASONALLY
COOL CONDITIONS FOR A PLEASANT WEEKEND AREAWIDE.
NEXT WEEK THE UPPER TROUGH MOVES THROUGH THE SOUTHERN PLAINS MON/TUE
INTO THE GREAT LAKES REGION BY MID WEEK WHILE LOCAL MOISTURE AND
TEMPS MODERATE AND INCREASE AS THE LOW LEVEL FLOW BECOMES SOUTHERLY.
SURFACE STORM SYSTEM TO MOVE WELL NORTH OF THE AREA...BUT ATTENDANT
COLD FRONT TO PUSH THROUGH THE GULF COAST REGION TUESDAY THEN THE FL
PENINSULA WEDNESDAY WITH OUR NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS. COOLER AND DRIER HIGH PRESSURE CONDITIONS TO BUILD
INTO THE REGION LATE NEXT WEEK.
&&
.AVIATION...
LOTS OF RAIN IN THE FORECAST FOR THE NEXT SEVERAL HOURS WITH A MIX
OF IFR/MVFR CONDITION. SHOWERS WILL BEGIN TO TAPER OFF BETWEEN
00-03Z ALTHOUGH PERIOD OF MAINLY MVFR CLOUDS ARE EXPECTED TO
LINGER THROUGH MUCH OF THE OVERNIGHT. VFR CONDITIONS RETURN TO ALL
TAF SITES AFTER 09Z AND WILL CONTINUE THROUGH THE DURATION OF THE
TAF PERIOD...AND BEYOND. WINDS SHIFT TO THE NORTHWEST THIS EVENING
AND WILL BE STEADY THROUGH THE OVERNIGHT.
&&
.MARINE...
A WEAK AREA OF LOW PRESSURE WILL MOVE NORTHEASTWARD ACROSS THE
FLORIDA PENINSULA THIS EVENING. A COLD FRONT TRAILING FROM THIS
LOW SINKS SOUTH AND EAST ACROSS THE FORECAST WATERS THROUGH EARLY
THIS EVENING...WITH WINDS SHIFTING TO THE NORTHWEST. AREAS OF
RAINFALL WILL FINALLY END WITH THE PASSAGE OF THIS FRONT THIS
EVENING...HOWEVER WINDS AND SEAS WILL QUICKLY BEGIN TO INCREASE.
CAUTIONARY LEVEL WINDS WILL QUICKLY DEVELOP OVER THE EASTERN GULF
OF MEXICO...WITH PERIODS OF ADVISORY WINDS NOW EXPECTED. THIS
PERIOD OF HAZARDOUS MARINE CONDITIONS SHOULD BE SHORT-LIVED AS
WINDS AND SEAS BEGIN TO SUBSIDE DURING FRIDAY. ALTHOUGH WINDS WILL
DROP BELOW ADVISORY LEVELS EARLY FRIDAY...RESIDUAL SEAS WILL BE
SLOWER TO SUBSIDE...AND ARE NOT ANTICIPATED TO DROP BELOW ADVISORY
LEVELS UNTIL MID/LATE MORNING FRIDAY. A RIDGE OF HIGH PRESSURE
MOVES TOWARD THE REGION DURING FRIDAY...AND SETTLES DIRECTLY OVER
THE AREA SATURDAY. THE HIGH THEN SHIFTS EASTWARD INTO THE ATLANTIC
SUNDAY. AFTER THE ADVISORY ENDS FRIDAY MORNING...GENERALLY LIGHT
WINDS...LOW SEAS...AND DRY CONDITIONS ARE IN THE FORECAST FOR THE
DURATION OF THE UPCOMING WEEKEND.
&&
.FIRE WEATHER...
A COLD FRONT WILL CROSS THE REGION THIS EVENING. WIDESPREAD SHOWERS
AND RAIN WILL BE IN THE FORECAST UNTIL THIS FRONT CLEAR THE REGION.
MUCH DRIER AND SOMEWHAT COOLER AIR WILL THEN ARRIVE ON NORTHWEST
WINDS DURING THE OVERNIGHT INTO FRIDAY MORNING. HIGH PRESSURE
APPROACHES THE REGION DURING FRIDAY...AND SETTLES OVERHEAD DURING
THE FIRST HALF OF THE UPCOMING WEEKEND. ENOUGH DRY AIR IS FORECAST
TO ARRIVE FOR FRIDAY TO RESULT IN RELATIVE HUMIDITY VALUES FALLING
NEAR OR SLIGHTLY BELOW 35 PERCENT FOR A BRIEF TIME FRIDAY AFTERNOON
AWAY FROM THE IMMEDIATE COAST. ERC VALUES WILL BE LOW IN THE WAKE OF
ALL THE RAIN THE PAST SEVERAL DAYS WHICH WILL PREVENT ANY RED FLAG
CONDITIONS FROM OCCURRING. A BRIEF PERIOD OF NEAR CRITICAL RELATIVE
HUMIDITY VALUES IS AGAIN POSSIBLE SATURDAY AFTERNOON. A SLOW INCREASE
IN LOW LEVEL MOISTURE BEGINNING SUNDAY INTO MONDAY WILL THEN PREVENT
CRITICAL LEVELS OF RELATIVE HUMIDITY DURING THE EARLY PORTION OF
NEXT WEEK.
FOG POTENTIAL...
AREAS OF SEA FOG NEAR THE COASTS OF PINELLAS...HILLSBOROUGH...PASCO...
MANATEE...AND HERNANDO COUNTIES WILL END THIS EVENING WITH THE PASSAGE
OF A COLD FRONT. BEHIND THIS FRONT...NO SIGNIFICANT FOG CONCERNS ARE
ANTICIPATED THROUGH AT LEAST SATURDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 50 63 47 69 / 40 0 0 0
FMY 56 68 47 71 / 40 0 0 0
GIF 50 66 46 70 / 50 0 0 0
SRQ 53 63 46 68 / 40 0 0 0
BKV 45 63 37 71 / 40 0 0 0
SPG 53 62 52 69 / 40 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR COASTAL
CHARLOTTE-COASTAL LEE-DESOTO-HIGHLANDS-INLAND
CHARLOTTE-INLAND LEE.
GULF WATERS...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
FRIDAY FOR COASTAL WATERS FROM BONITA BEACH TO
ENGLEWOOD FL OUT 20 NM-COASTAL WATERS FROM ENGLEWOOD
TO TARPON SPRINGS FL OUT 20 NM-COASTAL WATERS FROM
TARPON SPRINGS TO SUWANNEE RIVER FL OUT 20 NM-WATERS
FROM BONITA BEACH TO ENGLEWOOD FL OUT 20 TO 60 NM-
WATERS FROM ENGLEWOOD TO TARPON SPRINGS FL OUT 20 TO
60 NM-WATERS FROM TARPON SPRINGS TO SUWANNEE RIVER FL
OUT 20 TO 60 NM.
DENSE FOG ADVISORY UNTIL 7 PM EST THIS EVENING FOR COASTAL
WATERS FROM ENGLEWOOD TO TARPON SPRINGS FL OUT 20 NM-
COASTAL WATERS FROM TARPON SPRINGS TO SUWANNEE RIVER
FL OUT 20 NM-TAMPA BAY WATERS.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...DAVIS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1228 PM EST THU JAN 28 2016
.Aviation...
[Through 18Z Friday]...
Mainly IFR conditions due to cigs will persist at the TAF sites
through this afternoon. By this evening though, should see clouds
begin to clear from west to east. Light showers are spread across
the area and will continue on and off this afternoon.
&&
.Prev Discussion [1005 AM EST]...
.Near Term [Through Today]...
The rain continues to push to the east and diminish this morning
with only an area of light showers across the eastern half of the
CWA. There is an area of rain to the southwest of the CWA that the
HRRR develops and spreads into the land areas this
afternoon...mainly east of Panama City to Dothan. The HRRR has had
a good handle on the showers the past few hours and with this
update trended the PoPs more towards a combination of the HRRR
and ECAM which resulted in increasing PoPs for this afternoon. So
although there is a diminishing trend this morning, do expect to
see another round this afternoon.
Hourly temperature trends this morning are on track, but overall
high temperatures may be a tad on the high side, especially if the
second round of rain pans out.
.Short Term [Tonight Through Saturday]...
Nearly zonal flow will fill in behind the exiting mid/upper level
trough. Surface high pressure and a much drier air mass will build
in from the west and center over the local region by late Friday.
The high will then slide to our east with low level flow becoming
southerly on Saturday. We will see sunny and dry conditions with
near to slightly above seasonal temperatures.
.Long Term [Saturday Night Through Thursday]...
Enhanced mid/upper level ridging will develop late in the weekend
and early next week ahead of a deepening low pressure system moving
out of the Four Corners region and into the Central Plains by midday
Tuesday. This system will continue to deepen as it lifts
northeastward to the Great Lakes area by 12z Wednesday with showers
and possibly thunderstorms spreading across the local Tri-state
area Tuesday and Wednesday ahead of the associated cold front.
Min and max temps will be above seasonal levels through the
extended period with max temps as high and the lower to mid 70s
both Monday and Tuesday and min temps as warm as the mid to upper
50s both Monday night and Tuesday night.
.Marine...
Cautionary level winds and seas will continue through tonight
west of the Apalachicola river. These conditions will spRead to
the eastern legs tonight. Winds and seas will begin to decrease
Friday and become southerly on Saturday as surface high pressure
slides to our east.
.Fire Weather...
Moist conditions are expected this morning with areas of light rain.
Drier air will move in behind the front for Friday afternoon with
min RH values dipping into the 30s over a large part of the area.
Red flag conditions are not expected for the next several days.
.Hydrology...
Minor flooding continues for the Apalachicola River at Blountstown
due to releases from Woodruff Dam. The river along this stretch
continues in a broad flat crest with recession expected to begin
tonight. The lower part of the Choctawhatchee River basin is also
in flood. Caryville is forecast to drop below flood stage on
Thursday. Bruce is above moderate flood stage and is forecast to
crest Thursday morning. Additional rainfall totals over the next
36 hours will generally be under a half an inch, except 0.5-1 inch
totals will be possible across the eastern FL Big Bend. This is
not expected to produce any additional flooding.
For detailed information on specific river stages and forecasts,
please visit http://water.weather.gov/ahps2/index.php?wfo=tae.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 40 64 39 67 44 / 10 0 0 0 0
Panama City 44 61 46 65 53 / 0 0 0 0 0
Dothan 37 60 38 65 46 / 0 0 0 0 0
Albany 38 60 36 65 43 / 0 0 0 0 0
Valdosta 40 62 38 67 43 / 30 0 0 0 0
Cross City 41 64 39 67 43 / 40 0 0 0 0
Apalachicola 45 62 46 64 52 / 10 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...FIEUX
SHORT TERM...BARRY
LONG TERM...BARRY
AVIATION...FIEUX
MARINE...BARRY
FIRE WEATHER...DVD
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1005 AM EST THU JAN 28 2016
.Near Term [Through Today]...
The rain continues to push to the east and diminish this morning
with only an area of light showers across the eastern half of the
CWA. There is an area of rain to the southwest of the CWA that the
HRRR develops and spreads into the land areas this
afternoon...mainly east of Panama City to Dothan. The HRRR has had
a good handle on the showers the past few hours and with this
update trended the PoPs more towards a combination of the HRRR
and ECAM which resulted in increasing PoPs for this afternoon. So
although there is a diminishing trend this morning, do expect to
see another round this afternoon.
Hourly temperature trends this morning are on track, but overall
high temperatures may be a tad on the high side, especially if the
second round of rain pans out.
&&
.Prev Discussion [552 AM EST]...
.Short Term [Tonight Through Saturday]...
Nearly zonal flow will fill in behind the exiting mid/upper level
trough. Surface high pressure and a much drier air mass will build
in from the west and center over the local region by late Friday.
The high will then slide to our east with low level flow becoming
southerly on Saturday. We will see sunny and dry conditions with
near to slightly above seasonal temperatures.
.Long Term [Saturday Night Through Thursday]...
Enhanced mid/upper level ridging will develop late in the weekend
and early next week ahead of a deepening low pressure system moving
out of the Four Corners region and into the Central Plains by midday
Tuesday. This system will continue to deepen as it lifts
northeastward to the Great Lakes area by 12z Wednesday with showers
and possibly thunderstorms spreading across the local Tri-state
area Tuesday and Wednesday ahead of the associated cold front.
Min and max temps will be above seasonal levels through the
extended period with max temps as high and the lower to mid 70s
both Monday and Tuesday and min temps as warm as the mid to upper
50s both Monday night and Tuesday night.
.Aviation...
[Through 12z Friday] Low ceilings and areas of rain are expected
to persist through the morning hours with IFR to possibly LIFR
conditions. Clearing is expected from west to east through the
afternoon hours with VFR conditions returning this evening
areawide as a drier airmass moves into the area behind a cold
front.
.Marine...
Cautionary level winds and seas will continue through tonight
west of the Apalachicola river. These conditions will spRead to
the eastern legs tonight. Winds and seas will begin to decrease
Friday and become southerly on Saturday as surface high pressure
slides to our east.
.Fire Weather...
Moist conditions are expected this morning with areas of light rain.
Drier air will move in behind the front for Friday afternoon with
min RH values dipping into the 30s over a large part of the area.
Red flag conditions are not expected for the next several days.
.Hydrology...
Minor flooding continues for the Apalachicola River at Blountstown
due to releases from Woodruff Dam. The river along this stretch
continues in a broad flat crest with recession expected to begin
tonight. The lower part of the Choctawhatchee River basin is also
in flood. Caryville is forecast to drop below flood stage on
Thursday. Bruce is above moderate flood stage and is forecast to
crest Thursday morning. Additional rainfall totals over the next
36 hours will generally be under a half an inch, except 0.5-1 inch
totals will be possible across the eastern FL Big Bend. This is
not expected to produce any additional flooding.
For detailed information on specific river stages and forecasts,
please visit http://water.weather.gov/ahps2/index.php?wfo=tae.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 61 40 66 38 68 / 70 0 0 0 0
Panama City 59 44 62 46 66 / 100 0 0 0 0
Dothan 57 37 61 38 67 / 70 0 0 0 0
Albany 56 38 62 36 65 / 100 0 0 0 0
Valdosta 59 40 66 37 69 / 80 10 0 0 0
Cross City 65 41 66 38 69 / 70 10 0 0 0
Apalachicola 61 45 66 46 65 / 60 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...FIEUX
SHORT TERM...BARRY
LONG TERM...BARRY
AVIATION...DVD
MARINE...BARRY
FIRE WEATHER...DVD
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS MIAMI FL
612 AM EST THU JAN 28 2016
.AVIATION...
FOR THE SHORT TERM...SHOWERS CONTINUE TO STREAM NORTHEASTWARD ACROSS
THE SOUTH FLORIDA PENINSULA THIS MORNING WITH ONLY ISOLATED
THUNDERSTORM ACTIVITY THUS FAR. MOST OF THE TERMINALS WILL
EXPERIENCE LIGHT SHOWERS DURING THE MORNING HOURS WITH LOW
STRATUS NEAR 1 KFT TO 1500 FT POSSIBLE AND BRIEF PERIODS OF MVFR
TO NEAR IFR CONDITIONS WITH SHOWERS. LATEST GUIDANCE STILL
INDICATES ACTIVE CONVECTION AGAIN TODAY...POSSIBLY STARTING IN THE
NORTHWEST INTERIOR REGION LATER IN THE MORNING THEN ACROSS THE
REMAINDER OF THE PENINSULA MID-MORNING TO EARLY AFTERNOON WITH ALL
TERMINALS ASSIGNED VCTS BY 14Z OR 15Z...WITH THE OBVIOUS
UNCERTAINTY ON THE TIMING. A SLIGHT CHANCE OF SEVERE WEATHER
CONTINUES ACROSS THE REGION TODAY. GUIDANCE CONSISTENTLY
INDICATING STRONGER SOUTHWESTERLY WINDS BUILDING INTO THE REGION
AROUND 14-16Z DEPENDING ON THE TERMINAL. ACTIVE CONVECTION COULD
CONTINUE INTO THE EARLY EVENING HOURS WITH A CLEARING TREND
FORECAST AFTER 00Z THIS EVENING.
60
&&
.PREV DISCUSSION... /ISSUED 417 AM EST THU JAN 28 2016/
DISCUSSION...
SIMILAR TO YESTERDAY AT THIS TIME, WE WILL ONCE AGAIN BE WATCHING
THE EVOLUTION OF THUNDERSTORMS MOVING ACROSS THE GULF OF MEXICO, AS
LOW PRESSURE MOVES INTO THE EASTERN GULF, ALONG THE STALLED OUT
BOUNDARY. SHOWERS AND SOME EMBEDDED THUNDERSTORMS WILL FIRST AFFECT
THE WEST COAST AND NORTHWEST INTERIOR THIS AM. THE SOUTHERN EDGE
OF THIS LINE, NOW MOVING THROUGH THE WATERS OFF MAINLAND MONROE,
WILL NEED TO BE MONITORED CLOSELY, AS IT MOVES INTO BROWARD AND
MIAMI- DADE LATER THIS MORNING. THIS LINE COULD INTENSIFY AS IT
MOVES ACROSS THE PENINSULA TOWARDS BROWARD/MIAMI-DADE. 0-1 KM HELICITY AGAIN
SUPPORTS ROTATION AND POSSIBLE SPINUPS/ISOLATED WATERSPOUTS/TORNADOES
AS ACTIVITY CROSSES THE WEST COAST THIS AM AND MOVES EAST ACROSS
THE PENINSULA.
SHRTWV AND 140KT JET CROSSING FL LATER TODAY WILL FINALLY PUSH
THE FRONT THROUGH SOUTH FL THIS EVENING. LATER TODAY, MODELS HAVE
SLOWED DOWN ARRIVAL OF COLD FRONT ACROSS SOUTH FL. THIS WILL GIVE
THE SOUTHERN HALF OF THE REGION A FEW MORE HOURS OF HEATING AND
INCREASED INSTABILITY. WITH WINDS BECOMING MORE UNIDIRECTIONAL AND
VEERING NEAR THE SURFACE, LLVL HELICITY WILL DECREASE SOMEWHAT.
STILL THOUGH, ENOUGH TURNING IS LEFT IN THE WIND PROFILE FOR AN
ISOLATED TORNADO WITHIN THE MAIN SQUALL LINE WITH THE FRONT LATE
THIS AFTERNOON. WE COULD BE LOOKING AT AN AREA OF DAMAGING WINDS
WITHIN THE LINE CONSIDERING 40 KT LLVL JET/0-6KM SHEAR OF 45 M/S
IN THE MIA RAP SOUNDING FOR LATE THIS PM. AS USUAL, MITIGATING
FACTOR IN ALL OF THIS IS HOW MUCH RAIN FALLS THIS MORNING ACROSS
EXTREME SOUTH FL WITH SHOWERS CURRENTLY OVER THE GULF. SPC HAS
CONTINUED THE MARGINAL RISK FOR SOUTH FL. VERY WELL COULD BE
ANOTHER ACTIVE SEVERE WEATHER DAY ACROSS THE REGION.
WINDS WILL BE GUSTY LATE THIS MORNING AND AFTERNOON, ESPECIALLY
ACROSS THE SOUTHERN HALF. BUFKIT MOMENTUM TRANSFER DOES HAVE 25-30
KT GUSTS AT THE TOP OF THE MIXED LAYER. WIND GUSTS MAY BE NEAR
ADVISORY CRITERIA AT TIMES, ESPECIALLY WITH BREAKS/THINNING OF THE
CLOUD COVER.
NOT TO BE LOST IN ALL OF THIS, IS ADDITIONAL HEAVY RAINFALL WHICH
CAN LEAD TO PERHAPS MORE WIDESPREAD URBAN STREET FLOODING TODAY.
HEFTY RAINFALL TOTALS FROM YESTERDAY, 4-6" IN SOME SPOTS AND
HIGHLY ANOMALOUS PWATS/SPECIFIC HUMIDITY/WV MOISTURE TRANSPORT,
NECESSITATES A FLOOD WATCH FOR MOST OF THE CWA. FOR NOW, MIAMI-
DADE WILL BE LEFT OUT OF THE WATCH, CONSIDERING LOWER TOTALS
YESTERDAY. BUT A SLOW MOVING LINE OF HEAVY THUNDERSTORMS MAY BE
REASON ENOUGH TO EXTEND THE WATCH FURTHER SOUTH LATER TODAY.
MUCH COOLER AND DRIER AIR BEHIND THE FRONT COULD PUT THE NORTHWEST
INTERIOR AND COLLIER COUNTIES INTO THE LOWER 40S FOR LOWS SATURDAY
MORNING. SURFACE HIGH PRESSURE IS OVER THE STATE FOR MUCH OF THE
UPCOMING WEEKEND. TEMPS REBOUND QUICKLY ON SUNDAY WITH MOISTURE
INCREASING ALONG EXTREME SOUTH FL BY MONDAY WITH SOME SHOWERS COMING
NORTH FROM THE KEYS. NEXT FRONT PROGGED FOR THE MIDDLE OR END OF
NEXT WEEK, WITH SOME DISAGREEMENT BETWEEN THE EC AND THE GFS
REGARDING THE STRENGTH OF RIDGING OVER SOUTH FL, LEADS TO
UNCERTAINTY REGARDING THE AMOUNT OF PRECIP ALONG THE FRONT AND THE
DEPTH OF COOLER AIR BEHIND IT.
MARINE...
WINDS WILL INCREASE IN ASSOCIATION WITH THE COLD FRONTAL PASSAGE
THU AFTERNOON AND EVENING. A SMALL CRAFT ADVISORY HAS BEEN ISSUED.
STRONG THUNDERSTORMS WILL BE POSSIBLE IN BOTH THE ATLANTIC AND
GULF WATERS TODAY WITH LOCALLY HIGHER SEAS AND WINDS. SEAS WILL
BUILD BEHIND THE FRONT, ESPECIALLY IN THE GULF WITH HAZARDOUS SEAS
TO NEAR 7 FEET POSSIBLE THU NIGHT. HIGH PRESSURE ARRIVES TO FINISH
THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 58 72 48 / 90 40 10 0
FORT LAUDERDALE 81 57 72 52 / 80 70 10 0
MIAMI 81 61 72 52 / 80 70 10 0
NAPLES 75 56 68 46 / 90 20 10 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH THIS EVENING FOR FLZ067-068-071-072-168-172.
FLOOD WATCH THROUGH THIS EVENING FOR FLZ063-066-069-070.
AM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 7 PM EST
SATURDAY FOR AMZ630-650-651-670-671.
GM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST
SATURDAY FOR GMZ656-657-676.
&&
$$
SHORT TERM...
LONG TERM....
AVIATION...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
417 AM EST THU JAN 28 2016
.DISCUSSION...
SIMILAR TO YESTERDAY AT THIS TIME, WE WILL ONCE AGAIN BE WATCHING
THE EVOLUTION OF THUNDERSTORMS MOVING ACROSS THE GULF OF MEXICO, AS
LOW PRESSURE MOVES INTO THE EASTERN GULF, ALONG THE STALLED OUT
BOUNDARY. SHOWERS AND SOME EMBEDDED THUNDERSTORMS WILL FIRST AFFECT
THE WEST COAST AND NORTHWEST INTERIOR THIS AM. THE SOUTHERN EDGE
OF THIS LINE, NOW MOVING THROUGH THE WATERS OFF MAINLAND MONROE,
WILL NEED TO BE MONITORED CLOSELY, AS IT MOVES INTO BROWARD AND
MIAMI- DADE LATER THIS MORNING. THIS LINE COULD INTENSIFY AS IT
MOVES ACROSS THE PENINSULA TOWARDS BROWARD/MIAMI-DADE. 0-1 KM HELICITY AGAIN
SUPPORTS ROTATION AND POSSIBLE SPINUPS/ISOLATED WATERSPOUTS/TORNADOES
AS ACTIVITY CROSSES THE WEST COAST THIS AM AND MOVES EAST ACROSS
THE PENINSULA.
SHRTWV AND 140KT JET CROSSING FL LATER TODAY WILL FINALLY PUSH
THE FRONT THROUGH SOUTH FL THIS EVENING. LATER TODAY, MODELS HAVE
SLOWED DOWN ARRIVAL OF COLD FRONT ACROSS SOUTH FL. THIS WILL GIVE
THE SOUTHERN HALF OF THE REGION A FEW MORE HOURS OF HEATING AND
INCREASED INSTABILITY. WITH WINDS BECOMING MORE UNIDIRECTIONAL AND
VEERING NEAR THE SURFACE, LLVL HELICITY WILL DECREASE SOMEWHAT.
STILL THOUGH, ENOUGH TURNING IS LEFT IN THE WIND PROFILE FOR AN
ISOLATED TORNADO WITHIN THE MAIN SQUALL LINE WITH THE FRONT LATE
THIS AFTERNOON. WE COULD BE LOOKING AT AN AREA OF DAMAGING WINDS
WITHIN THE LINE CONSIDERING 40 KT LLVL JET/0-6KM SHEAR OF 45 M/S
IN THE MIA RAP SOUNDING FOR LATE THIS PM. AS USUAL, MITIGATING
FACTOR IN ALL OF THIS IS HOW MUCH RAIN FALLS THIS MORNING ACROSS
EXTREME SOUTH FL WITH SHOWERS CURRENTLY OVER THE GULF. SPC HAS
CONTINUED THE MARGINAL RISK FOR SOUTH FL. VERY WELL COULD BE
ANOTHER ACTIVE SEVERE WEATHER DAY ACROSS THE REGION.
WINDS WILL BE GUSTY LATE THIS MORNING AND AFTERNOON, ESPECIALLY
ACROSS THE SOUTHERN HALF. BUFKIT MOMENTUM TRANSFER DOES HAVE 25-30
KT GUSTS AT THE TOP OF THE MIXED LAYER. WIND GUSTS MAY BE NEAR
ADVISORY CRITERIA AT TIMES, ESPECIALLY WITH BREAKS/THINNING OF THE
CLOUD COVER.
NOT TO BE LOST IN ALL OF THIS, IS ADDITIONAL HEAVY RAINFALL WHICH
CAN LEAD TO PERHAPS MORE WIDESPREAD URBAN STREET FLOODING TODAY.
HEFTY RAINFALL TOTALS FROM YESTERDAY, 4-6" IN SOME SPOTS AND
HIGHLY ANOMALOUS PWATS/SPECIFIC HUMIDITY/WV MOISTURE TRANSPORT,
NECESSITATES A FLOOD WATCH FOR MOST OF THE CWA. FOR NOW, MIAMI-
DADE WILL BE LEFT OUT OF THE WATCH, CONSIDERING LOWER TOTALS
YESTERDAY. BUT A SLOW MOVING LINE OF HEAVY THUNDERSTORMS MAY BE
REASON ENOUGH TO EXTEND THE WATCH FURTHER SOUTH LATER TODAY.
MUCH COOLER AND DRIER AIR BEHIND THE FRONT COULD PUT THE NORTHWEST
INTERIOR AND COLLIER COUNTIES INTO THE LOWER 40S FOR LOWS SATURDAY
MORNING. SURFACE HIGH PRESSURE IS OVER THE STATE FOR MUCH OF THE
UPCOMING WEEKEND. TEMPS REBOUND QUICKLY ON SUNDAY WITH MOISTURE
INCREASING ALONG EXTREME SOUTH FL BY MONDAY WITH SOME SHOWERS COMING
NORTH FROM THE KEYS. NEXT FRONT PROGGED FOR THE MIDDLE OR END OF
NEXT WEEK, WITH SOME DISAGREEMENT BETWEEN THE EC AND THE GFS
REGARDING THE STRENGTH OF RIDGING OVER SOUTH FL, LEADS TO
UNCERTAINTY REGARDING THE AMOUNT OF PRECIP ALONG THE FRONT AND THE
DEPTH OF COOLER AIR BEHIND IT.
&&
.MARINE...
WINDS WILL INCREASE IN ASSOCIATION WITH THE COLD FRONTAL PASSAGE
THU AFTERNOON AND EVENING. A SMALL CRAFT ADVISORY HAS BEEN ISSUED.
STRONG THUNDERSTORMS WILL BE POSSIBLE IN BOTH THE ATLANTIC AND
GULF WATERS TODAY WITH LOCALLY HIGHER SEAS AND WINDS. SEAS WILL
BUILD BEHIND THE FRONT, ESPECIALLY IN THE GULF WITH HAZARDOUS SEAS
TO NEAR 7 FEET POSSIBLE THU NIGHT. HIGH PRESSURE ARRIVES TO FINISH
THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 58 72 48 / 90 60 10 0
FORT LAUDERDALE 81 57 72 52 / 80 70 10 0
MIAMI 81 61 72 52 / 80 70 10 0
NAPLES 75 56 68 46 / 90 40 10 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH THIS EVENING FOR FLZ067-068-071-072-168-172.
FLOOD WATCH THROUGH THIS EVENING FOR FLZ063-066-069-070.
AM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 7 PM EST
SATURDAY FOR AMZ630-650-651-670-671.
GM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST
SATURDAY FOR GMZ656-657-676.
&&
$$
SHORT TERM...21/KM
LONG TERM....21/KM
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
410 PM EST THU JAN 28 2016
.SYNOPSIS...
MOISTURE WILL DIMINISH TONIGHT AS LOW PRESSURE OFF THE COAST LIFTS
FARTHER NORTHEAST OF THE AREA. DRY HIGH PRESSURE WILL DOMINATE
OVER THE WEEKEND INTO EARLY NEXT WEEK WITH A WARMING TREND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOISTURE WILL REMAIN HIGH THROUGH THE AFTERNOON ASSOCIATED WITH
THE UPPER TROUGH AND COASTAL FRONT. THE LATEST ANALYSIS SHOWED
H85 COLD ADVECTION. THE FORECAST AREA WAS UNDER THE LEFT EXIT
REGION OF THE H25 JET. RAIN WAS MAINLY BEING SUPPORTED BY THE
UPPER-LEVEL TROUGH AND JET. THE MODELS INDICATE SUPPORT SHIFTING
EAST OF THE AREA THIS EVENING. USED THE HRRR FOR THE TIMING.
RADAR TRENDS SUPPORT MAINLY LIGHT RAIN. DECREASING CLOUDS WILL
OCCUR TONIGHT FROM WEST TO EAST WITH SKIES BECOMING MOSTLY CLEAR.
COLD ADVECTION AND CLEARING WILL BRING COOL TEMPERATURES TONIGHT.
THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE 30S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
UPPER LEVEL FLOW WILL TRANSITION TO ZONAL. SURFACE HIGH PRESSURE
AND DRIER AIR WILL SHIFT INTO THE SE CONUS...ENSURING FAIR
WEATHER. GUIDANCE INDICATING NEAR OR JUST ABOVE NORMAL TEMPS
FRI...WITH ABOVE NORMAL TEMPS SAT...AS SURFACE HIGH PRESSURE
CENTER SHIFTS TO OUR S/E.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MODELS INDICATE UPPER TROUGH WILL DIG INTO CENTRAL CONUS...WITH
UPPER RIDGE DEVELOPING OFFSHORE THE EAST COAST. SURFACE HIGH
CENTERED JUST TO OUR SE SUNDAY WILL SHIFT EAST...AS A FRONT
APPROACHES FROM THE WEST. THOUGH SOME TIMING DIFFERENCES
NOTED...GFS AND ECMWF BRING THE FRONT INTO OUR REGION LATE
TUE/WED TIME FRAME. AHEAD OF THE FRONT...EXPECT ABOVE NORMAL
TEMPS.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
WIDESPREAD IFR/LIFR CONDITIONS ACROSS THE TAF SITES WITH PATCHES OF LIGHT
RAIN CROSSING THE AREA. DEEP MOISTURE WILL MOVE EAST OF THE TAF SITES
AROUND 29/00Z ALLOWING RAIN TO END. LOW CLOUDS WILL BE SLOWER TO CLEAR
POSSIBLY LINGERING IN THE 06Z-09Z TIME FRAME.
STILL EXPECT DECREASING CLOUDS LATE TONIGHT FROM WEST TO EAST TONIGHT WITH
SKIES BECOMING MOSTLY CLEAR. LINGERING LOW-LEVEL MOISTURE MAY SUPPORT FOG
THROUGH THE NIGHT. EXPECT VFR ALL TAF SITES BY 29/12Z. THE GFS LAMP AND
NAM BUFKIT MOMENTUM TRANSFER TOOL SUPPORTED GUSTS AROUND 18 KNOTS BEGINNING
AROUND 29/15Z.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
209 PM EST THU JAN 28 2016
.SYNOPSIS...
MOISTURE WILL DIMINISH TONIGHT AS LOW PRESSURE OFF THE COAST LIFTS
FARTHER NORTHEAST OF THE AREA. DRY HIGH PRESSURE WILL DOMINATE
OVER THE WEEKEND INTO EARLY NEXT WEEK WITH A WARMING TREND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOISTURE WILL REMAIN HIGH THROUGH THE AFTERNOON ASSOCIATED WITH
THE UPPER TROUGH AND COASTAL FRONT. THE LATEST ANALYSIS SHOWED
H85 COLD ADVECTION. THE FORECAST AREA WAS UNDER THE LEFT EXIT
REGION OF THE H25 JET. RAIN WAS MAINLY BEING SUPPORTED BY THE
UPPER-LEVEL TROUGH AND JET. THE MODELS INDICATE SUPPORT SHIFTING
EAST OF THE AREA THIS EVENING. USED THE HRRR FOR THE TIMING.
RADAR TRENDS SUPPORT MAINLY LIGHT RAIN. DECREASING CLOUDS WILL
OCCUR TONIGHT FROM WEST TO EAST WITH SKIES BECOMING MOSTLY CLEAR.
COLD ADVECTION AND CLEARING WILL BRING COOL TEMPERATURES TONIGHT.
THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE 30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER LEVEL FLOW WILL TRANSITION TO ZONAL. SURFACE HIGH PRESSURE
AND DRIER AIR WILL SHIFT INTO THE SE CONUS...ENSURING FAIR
WEATHER. GUIDANCE INDICATING NEAR OR JUST ABOVE NORMAL TEMPS
FRI...WITH ABOVE NORMAL TEMPS SAT...AS SURFACE HIGH PRESSURE
CENTER SHIFTS TO OUR S/E.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS INDICATE UPPER TROUGH WILL DIG INTO CENTRAL CONUS...WITH
UPPER RIDGE DEVELOPING OFFSHORE THE EAST COAST. SURFACE HIGH
CENTERED JUST TO OUR SE SUNDAY WILL SHIFT EAST...AS A FRONT
APPROACHES FROM THE WEST. THOUGH SOME TIMING DIFFERENCES
NOTED...GFS AND ECMWF BRING THE FRONT INTO OUR REGION LATE
TUE/WED TIME FRAME. AHEAD OF THE FRONT...EXPECT ABOVE NORMAL
TEMPS.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
IFR CONDITIONS IN RAIN AND FOG WERE OCCURRING AT TAF ISSUANCE
TIME. THE MOISTURE WAS ASSOCIATED WITH THE UPPER TROUGH AND
COASTAL FRONT. THE MODELS AND SATELLITE TRENDS INDICATE SUPPORT
SHIFTING EAST OF THE AREA THIS EVENING. DECREASING CLOUDS WILL
OCCUR FROM WEST TO EAST TONIGHT WITH SKIES BECOMING MOSTLY CLEAR.
LINGERING HIGH LOW-LEVEL MOISTURE MAY SUPPORT FOG THROUGH THE
NIGHT. USED THE HRRR FOR THE TIMING OF DIMINISHING RAIN AND LEANED
TOWARD THE GFS LAMP FOR THE CEILING AND VISIBILITY FORECAST. THE
GFS LAMP AND NAM BUFKIT MOMENTUM TRANSFER TOOL SUPPORTED GUSTS
AROUND 18 KNOTS BEGINNING AROUND 15Z.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
124 PM EST THU JAN 28 2016
.SYNOPSIS...
MOISTURE WILL REMAIN HIGH ACROSS THE AREA THIS AFTERNOON AS WEAK
LOW PRESSURE MOVES NORTHEAST OFF THE CAROLINA COAST. THIS WILL
RESULT IN PERIODS OF LIGHT RAIN. DRY HIGH PRESSURE WILL DOMINATE
OVER THE WEEKEND INTO EARLY NEXT WEEK WITH A WARMING TREND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOISTURE WILL REMAIN HIGH THROUGH THE AFTERNOON ASSOCIATED WITH
THE UPPER TROUGH AND COASTAL FRONT. RAIN WAS OCCURRING OVER MOST
OF THE AREA EARLY THIS AFTERNOON. THE LATEST ANALYSIS SHOWED H85
COLD ADVECTION. THE FORECAST AREA WAS UNDER THE LEFT EXIT REGION
OF THE H25 JET. THE RAIN WAS MAINLY BEING SUPPORTED BY THE UPPER-
LEVEL TROUGH AND JET. THE MODELS INDICATE SUPPORT SHIFTING EAST OF
THE AREA LATE THIS AFTERNOON AND EVENING. USED THE HRRR FOR THE
TIMING. RADAR TRENDS SUPPORT MAINLY LIGHT RAIN. DECREASING CLOUDS
WILL OCCUR THIS EVENING FROM WEST TO EAST WITH SKIES BECOMING
MOSTLY CLEAR. LITTLE TEMPERATURE CHANGE WILL OCCUR THIS AFTERNOON.
THE COLD ADVECTION AND CLEARING WILL BRING COOL TEMPERATURES
TONIGHT. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER LEVEL FLOW WILL TRANSITION TO ZONAL. SURFACE HIGH PRESSURE
AND DRIER AIR WILL SHIFT INTO THE SE CONUS...ENSURING FAIR
WEATHER. GUIDANCE INDICATING NEAR OR JUST ABOVE NORMAL TEMPS
FRI...WITH ABOVE NORMAL TEMPS SAT...AS SURFACE HIGH PRESSURE
CENTER SHIFTS TO OUR S/E.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MODELS INDICATE UPPER TROUGH WILL DIG INTO CENTRAL CONUS...WITH
UPPER RIDGE DEVELOPING OFFSHORE THE EAST COAST. SURFACE HIGH
CENTERED JUST TO OUR SE SUNDAY WILL SHIFT EAST...AS A FRONT
APPROACHES FROM THE WEST. THOUGH SOME TIMING DIFFERENCES
NOTED...GFS AND ECMWF BRING THE FRONT INTO OUR REGION LATE
TUE/WED TIME FRAME. AHEAD OF THE FRONT...EXPECT ABOVE NORMAL
TEMPS.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
MOISTURE WILL REMAIN HIGH THROUGH THE AFTERNOON ASSOCIATED WITH
THE UPPER TROUGH AND COASTAL FRONT. RAIN WAS OCCURRING WITH IFR
CONDITIONS EARLY THIS AFTERNOON. THE LATEST ANALYSIS SHOWED H85
COLD ADVECTION. THE FORECAST AREA WAS UNDER THE LEFT EXIT REGION
OF THE H25 JET. THE RAIN WAS MAINLY BEING SUPPORTED BY THE UPPER-
LEVEL TROUGH AND JET. THE MODELS INDICATE SUPPORT SHIFTING EAST OF
THE AREA LATE THIS AFTERNOON INTO THE EVENING. DECREASING CLOUDS
WILL OCCUR THIS EVENING FROM WEST TO EAST WITH SKIES BECOMING
MOSTLY CLEAR. LINGERING HIGH LOW-LEVEL MOISTURE MAY SUPPORT FOG
THROUGH THE NIGHT. USED THE HRRR FOR THE TIMING OF DIMINISHING
RAIN AND LEANED TOWARD THE GFS LAMP FOR THE CEILING AND VISIBILITY
FORECAST. THE GFS LAMP AND NAM BUFKIT MOMENTUM TRANSFER TOOL
SUPPORTS GUSTS AROUND 18 KNOTS BEGINNING AROUND 15Z.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1222 PM EST THU JAN 28 2016
.SYNOPSIS...
MOISTURE WILL REMAIN HIGH ACROSS THE AREA THIS AFTERNOON AS WEAK
LOW PRESSURE MOVES NORTHEAST OFF THE CAROLINA COAST. THIS WILL
RESULT IN PERIODS OF LIGHT RAIN. DRY HIGH PRESSURE WILL DOMINATE
OVER THE WEEKEND WITH TEMPERATURES ABOVE NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOISTURE WILL REMAIN HIGH THROUGH THE AFTERNOON ASSOCIATED WITH
THE UPPER TROUGH AND COASTAL FRONT. RAIN WAS OCCURRING OVER MOST
OF THE AREA EARLY THIS AFTERNOON. THE LATEST ANALYSIS SHOWED H85
COLD ADVECTION. THE FORECAST AREA WAS UNDER THE LEFT EXIT REGION
OF THE H25 JET. THE RAIN WAS MAINLY BEING SUPPORTED BY THE UPPER-
LEVEL TROUGH AND JET. THE MODELS INDICATE SUPPORT SHIFTING EAST OF
THE AREA LATE THIS AFTERNOON AND EVENING. USED THE HRRR FOR THE
TIMING. RADAR TRENDS SUPPORT MAINLY LIGHT RAIN. DECREASING CLOUDS
WILL OCCUR THIS EVENING FROM WEST TO EAST WITH SKIES BECOMING
MOSTLY CLEAR. LITTLE TEMPERATURE CHANGE WILL OCCUR THIS AFTERNOON.
THE COLD ADVECTION AND CLEARING WILL BRING COOL TEMPERATURES
TONIGHT. THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE
30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
IT SHOULD BE SUNNY FRIDAY AND SATURDAY AS THE PRESSURE RIDGE
MOVES INTO THE AREA FROM THE WEST AND OFF THE SOUTH CAROLINA COAST
SATURDAY. THE TEMPERATURE GUIDANCE WAS CONSISTENT AND WARMING
EXPECTED AS WARM ADVECTION DEVELOPS. SO MAXIMUM TEMPERATURES ABOVE
NORMAL. FRIDAY NIGHT TEMPERATURES SHOULD BE COLD WITH FAVORABLE
RADIATIONAL COOLING CONDITIONS....FREEZING TEMPS EXPECTED.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE GFS AND ECMWF DEPICT A DRY PATTERN WITH A PRESSURE RIDGE OFF
THE SOUTHEAST COAST DOMINATING THROUGH MONDAY. THE MODELS KEEP
SIGNIFICANT MOISTURE WEST AND NORTH OF THE FORECAST AREA. THE
MODELS SHOW A MOISTURE INCREASE TUESDAY AHEAD OF A COLD FRONT
FORECAST TO MOVE INTO THE AREA TUESDAY NIGHT OR WEDNESDAY. THE GFS
ENSEMBLE MEANS SUPPORT POPS NEAR 20 PERCENT TUESDAY AND HIGHER
POPS BY WEDNESDAY. WELL ABOVE NORMAL TEMPERATURES THROUGH MOST OF
THE PERIOD.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
MOISTURE WILL REMAIN HIGH THROUGH THE AFTERNOON ASSOCIATED WITH
THE UPPER TROUGH AND COASTAL FRONT. RAIN WAS OCCURRING WITH IFR
CONDITIONS EARLY THIS AFTERNOON. THE LATEST ANALYSIS SHOWED H85
COLD ADVECTION. THE FORECAST AREA WAS UNDER THE LEFT EXIT REGION
OF THE H25 JET. THE RAIN WAS MAINLY BEING SUPPORTED BY THE UPPER-
LEVEL TROUGH AND JET. THE MODELS INDICATE SUPPORT SHIFTING EAST OF
THE AREA LATE THIS AFTERNOON INTO THE EVENING. DECREASING CLOUDS
WILL OCCUR THIS EVENING FROM WEST TO EAST WITH SKIES BECOMING
MOSTLY CLEAR. LINGERING HIGH LOW-LEVEL MOISTURE MAY SUPPORT FOG
THROUGH THE NIGHT. USED THE HRRR FOR THE TIMING OF DIMINISHING
RAIN AND LEANED TOWARD THE GFS LAMP FOR THE CEILING AND VISIBILITY
FORECAST. THE GFS LAMP AND NAM BUFKIT MOMENTUM TRANSFER TOOL
SUPPORTS GUSTS AROUND 18 KNOTS BEGINNING AROUND 15Z.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1010 AM EST THU JAN 28 2016
.SYNOPSIS...
MOISTURE WILL REMAIN HIGH ACROSS THE AREA THIS AFTERNOON AS WEAK
LOW PRESSURE MOVES NORTHEAST OFF THE CAROLINA COAST. THIS WILL
RESULT IN PERIODS OF LIGHT RAIN. DRY HIGH PRESSURE WILL DOMINATE
OVER THE WEEKEND WITH TEMPERATURES ABOVE NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOISTURE WILL REMAIN HIGH THROUGH THE AFTERNOON ASSOCIATED WITH
THE UPPER TROUGH AND COASTAL FRONT. RAIN WAS OCCURRING OVER MOST
OF THE AREA. THE LATEST ANALYSIS SHOWED H85 COLD ADVECTION. THE
FORECAST AREA WAS UNDER THE RIGHT EXIT REGION OF THE H25 JET. THE
RAIN WAS MAINLY BEING SUPPORTED BY THE UPPER-LEVEL TROUGH AND
JET. THE MODELS INDICATE SUPPORT SHIFTING EAST OF THE AREA LATE
THIS AFTERNOON INTO THE EVENING. USED THE HRRR FOR THE TIMING.
RADAR TRENDS SUPPORT MAINLY LIGHT RAIN. DECREASING CLOUDS WILL
OCCUR THIS EVENING FROM WEST TO EAST WITH SKIES BECOMING MOSTLY
CLEAR. LITTLE TEMPERATURE CHANGE WILL OCCUR THIS AFTERNOON. THE
COLD ADVECTION AND CLEARING WILL BRING COOL TEMPERATURES TONIGHT.
THE GUIDANCE WAS CLOSE WITH LOWS MAINLY IN THE MIDDLE 30S.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
IT SHOULD BE SUNNY FRIDAY AND SATURDAY AS THE PRESSURE RIDGE
MOVES INTO THE AREA FROM THE WEST AND OFF THE SOUTH CAROLINA COAST
SATURDAY. THE TEMPERATURE GUIDANCE WAS CONSISTENT AND WARMING
EXPECTED AS WARM ADVECTION DEVELOPS. SO MAXIMUM TEMPERATURES ABOVE
NORMAL. FRIDAY NIGHT TEMPERATURES SHOULD BE COLD WITH FAVORABLE
RADIATIONAL COOLING CONDITIONS....FREEZING TEMPS EXPECTED.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE GFS AND ECMWF DEPICT A DRY PATTERN WITH A PRESSURE RIDGE OFF
THE SOUTHEAST COAST DOMINATING THROUGH MONDAY. THE MODELS KEEP
SIGNIFICANT MOISTURE WEST AND NORTH OF THE FORECAST AREA. THE
MODELS SHOW A MOISTURE INCREASE TUESDAY AHEAD OF A COLD FRONT
FORECAST TO MOVE INTO THE AREA TUESDAY NIGHT OR WEDNESDAY. THE GFS
ENSEMBLE MEANS SUPPORT POPS NEAR 20 PERCENT TUESDAY AND HIGHER
POPS BY WEDNESDAY. WELL ABOVE NORMAL TEMPERATURES THROUGH MOST OF
THE PERIOD.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
MOISTURE WILL REMAIN HIGH THROUGH THE AFTERNOON ASSOCIATED WITH
THE UPPER TROUGH AND COASTAL FRONT. RAIN WAS OCCURRING WITH IFR
CONDITIONS. THE LATEST ANALYSIS SHOWED H85 COLD ADVECTION. THE
FORECAST AREA WAS UNDER THE RIGHT EXIT REGION OF THE H25 JET. THE
RAIN WAS MAINLY BEING SUPPORTED BY THE UPPER-LEVEL TROUGH AND
JET. THE MODELS INDICATE SUPPORT SHIFTING EAST OF THE AREA LATE
THIS AFTERNOON INTO THE EVENING. DECREASING CLOUDS WILL OCCUR
THIS EVENING FROM WEST TO EAST WITH SKIES BECOMING MOSTLY CLEAR.
USED THE HRRR FOR THE TIMING OF DIMINISHING RAIN AND LEANED
TOWARD THE GFS LAMP FOR THE CEILING AND VISIBILITY FORECAST.
NORTHEAST TO NORTH WINDS 10 KNOTS OR LESS SHOULD BECOME WESTERLY
AFTER 29/00Z AS LOW PRESSURE OFF THE COAST MOVES TO THE MID-
ATLANTIC REGION.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1150 AM CST THU JAN 28 2016
.UPDATE...
ISSUED AT 959 AM CST THU JAN 28 2016
Updated the forecast today mainly for sky cover with clouds a bit
slower to increase from the north with much of CWA still enjoying
sunny skies at 10 am. Otherwise rest of forecast looks good
today. Broken to overcast clouds with bases at or below 6k ft
along and north of I-80 (just north of CWA currently), will
spread se across central IL during this afternoon, moving into
northern counties during midday. These lower clouds due to a
clipper system over WI and northern IL that digs se across IN and
eastern IL by sunset. Brunt of its moisture to stay ne of central
IL this afternoon, though could be a few flurries or sprinkles far
ne CWA, ne of I-74. Temps currently in the upper 30s and lower
40s, and should only climb a few more degrees with 40F northern
CWA and mid 40s southern/sw CWA. Breezy WSW winds of 10-20 mph and
gusts of 20-30 mph to turn West to NW during the afternoon as a
trof slides se across central IL.
&&
.SHORT TERM...(Today)
ISSUED AT 324 AM CST THU JAN 28 2016
Clipper system noted on 08z/2am water vapor imagery over Lake
Superior will continue to track eastward today, remaining well to
the northeast of central Illinois. Meanwhile, low clouds in the
wake of the system extending back into the eastern Dakotas will
begin to sink southward. NAM RH profiles appear to be a bit too
aggressive with the southward push, so have trended toward the
slower GFS. Based on current satellite trends and GFS forecast,
have started the day mostly sunny across the board, followed by
increasing clouds from north to south during the late morning into
the afternoon. By the end of the day, skies will be mostly cloudy
across the entire KILX CWA. NAM hints at some light precip skirting
the far NE this afternoon as a trailing trough axis swings through
the area. HRRR is even more bullish, with the latest run showing
precip extending as far west as the I-55 corridor. Think this is
way overdone, so will disregard the HRRR solution. Will however
mention a chance for flurries/sprinkles along/northeast of a
Champaign to Paris line.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 324 AM CST THU JAN 28 2016
Substantial warm-up is still on tap for this weekend as zonal flow
pattern develops across the CONUS and a Pacific-origin airmass
arrives. High temperatures on Friday will be in the lower 40s, then
will climb well into the 50s for both Saturday and Sunday. An
approaching frontal boundary will spread clouds and perhaps a few
rain showers into the area on Sunday: however, weak upper support
and a lack of deep-layer moisture warrants only low chance PoPs.
Big weather story continues to be the development of a major winter
storm early next week. 00z Jan 28 models are in excellent agreement
with the track/timing of this system, and the thermal profiles of
the individual models have also come into better agreement.
GFS/ECMWF/GEM all show surface low pressure developing over the
Texas panhandle Monday evening...then tracking northeastward into
northwest Illinois by Tuesday evening. This particular track will
keep the KILX CWA in the warm sector of the system and lead to
mainly a rain event. Earlier concerns about a potential period of
freezing rain Monday night have been eased with the latest model
run, as surface temps are expected to remain above freezing and the
elevated warm layer achieves max temps of 5-8C by 12z Tue. Have
therefore gone with likely PoPs for rain everywhere Monday night
into Tuesday. With warm/moist air surging northward ahead of the
approaching system, some fairly impressive instability will develop
across the central/eastern CWA Tuesday afternoon. GFS SbCAPEs reach
600-800J/kg while lifted index values drop into the -3 to -5C range.
In addition, 0-6km bulk shear increases to 70-80kt as a strong mid-
level jet develops in advance of the short-wave trough. Given such
strong mid-winter parameters, have added a chance for thunderstorms
to the forecast east of the I-55 corridor on Tuesday.
Both the GFS and ECMWF show the dry slot of the system arriving late
Tuesday afternoon/evening, leading to the end of the significant
precipitation. Based on current projections, it appears rainfall
amounts Monday night through Tuesday will range from 1 to 1.50. As
the low lifts into the Great Lakes, colder air will arrive Tuesday
night and deformation zone precip will arrive from the west.
Thermal profiles are initially warm enough to support rain early
in the evening, but then cool sufficiently for snow Tuesday night
into Wednesday. While the vast majority of the snow will fall
west of the Mississippi River across Iowa/Wisconsin, some light
snow accumulation will be possible across the western half of the
CWA as the precip departs and comes to an end on Wednesday. In
addition, strong winds gusting to at least 30mph and temperatures
falling into the 20s and 30s will make Wednesday a blustery/cold
day.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1150 AM CST THU JAN 28 2016
The leading edge of an area of low clouds is moving its way into
central IL from the north at about 20-25 mph. The clouds on the
leading edge are mainly diurnally driven, so the ceilings are up
around 5000 ft. The lower, MVFR ceilings are back in northern IA
and southern WI with the best forcing associated with the
shortwave trough. Thus, have adjusted the previous TAFs to slow
down the timing on the MVFR ceilings to early this evening.
The biggest question was how quickly the lower clouds and MVFR
ceilings would depart central and eastern IL. The NAM and HRRR
want to keep the low level moisture and clouds in longer, while
the GFS and many of the short range models move the clouds out by
late this evening. The CONSSHort blend has been doing a good job
with the movement of the clouds. Thus, will lean toward the CONS
Short and will keep the MVFR ceilings in for central and eastern
IL TAF sites until 06-09z and then scatter out the clouds as a
surface ridge axis and subsidence approach from the west.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Miller
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
959 AM CST THU JAN 28 2016
.UPDATE...
ISSUED AT 959 AM CST THU JAN 28 2016
Updated the forecast today mainly for sky cover with clouds a bit
slower to increase from the north with much of CWA still enjoying
sunny skies at 10 am. Otherwise rest of forecast looks good
today. Broken to overcast clouds with bases at or below 6k ft
along and north of I-80 (just north of CWA currently), will
spread se across central IL during this afternoon, moving into
northern counties during midday. These lower clouds due to a
clipper system over WI and northern IL that digs se across IN and
eastern IL by sunset. Brunt of its moisture to stay ne of central
IL this afternoon, though could be a few flurries or sprinkles far
ne CWA, ne of I-74. Temps currently in the upper 30s and lower
40s, and should only climb a few more degrees with 40F northern
CWA and mid 40s southern/sw CWA. Breezy WSW winds of 10-20 mph and
gusts of 20-30 mph to turn West to NW during the afternoon as a
trof slides se across central IL.
&&
.SHORT TERM...(Today)
ISSUED AT 324 AM CST THU JAN 28 2016
Clipper system noted on 08z/2am water vapor imagery over Lake
Superior will continue to track eastward today, remaining well to
the northeast of central Illinois. Meanwhile, low clouds in the
wake of the system extending back into the eastern Dakotas will
begin to sink southward. NAM RH profiles appear to be a bit too
aggressive with the southward push, so have trended toward the
slower GFS. Based on current satellite trends and GFS forecast,
have started the day mostly sunny across the board, followed by
increasing clouds from north to south during the late morning into
the afternoon. By the end of the day, skies will be mostly cloudy
across the entire KILX CWA. NAM hints at some light precip skirting
the far NE this afternoon as a trailing trough axis swings through
the area. HRRR is even more bullish, with the latest run showing
precip extending as far west as the I-55 corridor. Think this is
way overdone, so will disregard the HRRR solution. Will however
mention a chance for flurries/sprinkles along/northeast of a
Champaign to Paris line.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 324 AM CST THU JAN 28 2016
Substantial warm-up is still on tap for this weekend as zonal flow
pattern develops across the CONUS and a Pacific-origin airmass
arrives. High temperatures on Friday will be in the lower 40s, then
will climb well into the 50s for both Saturday and Sunday. An
approaching frontal boundary will spread clouds and perhaps a few
rain showers into the area on Sunday: however, weak upper support
and a lack of deep-layer moisture warrants only low chance PoPs.
Big weather story continues to be the development of a major winter
storm early next week. 00z Jan 28 models are in excellent agreement
with the track/timing of this system, and the thermal profiles of
the individual models have also come into better agreement.
GFS/ECMWF/GEM all show surface low pressure developing over the
Texas panhandle Monday evening...then tracking northeastward into
northwest Illinois by Tuesday evening. This particular track will
keep the KILX CWA in the warm sector of the system and lead to
mainly a rain event. Earlier concerns about a potential period of
freezing rain Monday night have been eased with the latest model
run, as surface temps are expected to remain above freezing and the
elevated warm layer achieves max temps of 5-8C by 12z Tue. Have
therefore gone with likely PoPs for rain everywhere Monday night
into Tuesday. With warm/moist air surging northward ahead of the
approaching system, some fairly impressive instability will develop
across the central/eastern CWA Tuesday afternoon. GFS SbCAPEs reach
600-800J/kg while lifted index values drop into the -3 to -5C range.
In addition, 0-6km bulk shear increases to 70-80kt as a strong mid-
level jet develops in advance of the short-wave trough. Given such
strong mid-winter parameters, have added a chance for thunderstorms
to the forecast east of the I-55 corridor on Tuesday.
Both the GFS and ECMWF show the dry slot of the system arriving late
Tuesday afternoon/evening, leading to the end of the significant
precipitation. Based on current projections, it appears rainfall
amounts Monday night through Tuesday will range from 1 to 1.50. As
the low lifts into the Great Lakes, colder air will arrive Tuesday
night and deformation zone precip will arrive from the west.
Thermal profiles are initially warm enough to support rain early
in the evening, but then cool sufficiently for snow Tuesday night
into Wednesday. While the vast majority of the snow will fall
west of the Mississippi River across Iowa/Wisconsin, some light
snow accumulation will be possible across the western half of the
CWA as the precip departs and comes to an end on Wednesday. In
addition, strong winds gusting to at least 30mph and temperatures
falling into the 20s and 30s will make Wednesday a blustery/cold
day.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 533 AM CST THU JAN 28 2016
Skies are clear at all TAF sites to start, but a large area of
clouds is seen on satellite loops and will be advecting into the
area and covering the sites later this morning. Cig heights may
start as VFR...above 3kft, but lower MVFR cigs will be quick to
follow so will just have all sites with MVFR cigs when clouds
arrive. The MVFR cigs will continue through the afternoon and into
the evening. Models and bufkit data differ on whether any
scattering out or clearing of clouds will occur tonight. Due to
the uncertainty, will just keep clouds going through remainder of
TAF period at MVFR levels. Winds will be southwest to westerly
today, but then become northwesterly this evening. Wind speeds
will increase and all sites could see some gusts of 20kts or more
during the afternoon. After sunset, speeds will diminish.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
533 AM CST THU JAN 28 2016
.SHORT TERM...(Today)
ISSUED AT 324 AM CST THU JAN 28 2016
Clipper system noted on 08z/2am water vapor imagery over Lake
Superior will continue to track eastward today, remaining well to
the northeast of central Illinois. Meanwhile, low clouds in the
wake of the system extending back into the eastern Dakotas will
begin to sink southward. NAM RH profiles appear to be a bit too
aggressive with the southward push, so have trended toward the
slower GFS. Based on current satellite trends and GFS forecast,
have started the day mostly sunny across the board, followed by
increasing clouds from north to south during the late morning into
the afternoon. By the end of the day, skies will be mostly cloudy
across the entire KILX CWA. NAM hints at some light precip skirting
the far NE this afternoon as a trailing trough axis swings through
the area. HRRR is even more bullish, with the latest run showing
precip extending as far west as the I-55 corridor. Think this is
way overdone, so will disregard the HRRR solution. Will however
mention a chance for flurries/sprinkles along/northeast of a
Champaign to Paris line.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 324 AM CST THU JAN 28 2016
Substantial warm-up is still on tap for this weekend as zonal flow
pattern develops across the CONUS and a Pacific-origin airmass
arrives. High temperatures on Friday will be in the lower 40s, then
will climb well into the 50s for both Saturday and Sunday. An
approaching frontal boundary will spread clouds and perhaps a few
rain showers into the area on Sunday: however, weak upper support
and a lack of deep-layer moisture warrants only low chance PoPs.
Big weather story continues to be the development of a major winter
storm early next week. 00z Jan 28 models are in excellent agreement
with the track/timing of this system, and the thermal profiles of
the individual models have also come into better agreement.
GFS/ECMWF/GEM all show surface low pressure developing over the
Texas panhandle Monday evening...then tracking northeastward into
northwest Illinois by Tuesday evening. This particular track will
keep the KILX CWA in the warm sector of the system and lead to
mainly a rain event. Earlier concerns about a potential period of
freezing rain Monday night have been eased with the latest model
run, as surface temps are expected to remain above freezing and the
elevated warm layer achieves max temps of 5-8C by 12z Tue. Have
therefore gone with likely PoPs for rain everywhere Monday night
into Tuesday. With warm/moist air surging northward ahead of the
approaching system, some fairly impressive instability will develop
across the central/eastern CWA Tuesday afternoon. GFS SbCAPEs reach
600-800J/kg while lifted index values drop into the -3 to -5C range.
In addition, 0-6km bulk shear increases to 70-80kt as a strong mid-
level jet develops in advance of the short-wave trough. Given such
strong mid-winter parameters, have added a chance for thunderstorms
to the forecast east of the I-55 corridor on Tuesday.
Both the GFS and ECMWF show the dry slot of the system arriving late
Tuesday afternoon/evening, leading to the end of the significant
precipitation. Based on current projections, it appears rainfall
amounts Monday night through Tuesday will range from 1 to 1.50. As
the low lifts into the Great Lakes, colder air will arrive Tuesday
night and deformation zone precip will arrive from the west.
Thermal profiles are initially warm enough to support rain early
in the evening, but then cool sufficiently for snow Tuesday night
into Wednesday. While the vast majority of the snow will fall
west of the Mississippi River across Iowa/Wisconsin, some light
snow accumulation will be possible across the western half of the
CWA as the precip departs and comes to an end on Wednesday. In
addition, strong winds gusting to at least 30mph and temperatures
falling into the 20s and 30s will make Wednesday a blustery/cold
day.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 533 AM CST THU JAN 28 2016
Skies are clear at all TAF sites to start, but a large area of
clouds is seen on satellite loops and will be advecting into the
area and covering the sites later this morning. Cig heights may
start as VFR...above 3kft, but lower MVFR cigs will be quick to
follow so will just have all sites with MVFR cigs when clouds
arrive. The MVFR cigs will continue through the afternoon and into
the evening. Models and bufkit data differ on whether any
scattering out or clearing of clouds will occur tonight. Due to
the uncertainty, will just keep clouds going through remainder of
TAF period at MVFR levels. Winds will be southwest to westerly
today, but then become northwesterly this evening. Wind speeds
will increase and all sites could see some gusts of 20kts or more
during the afternoon. After sunset, speeds will diminish.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
324 AM CST THU JAN 28 2016
.SHORT TERM...(Today)
ISSUED AT 324 AM CST THU JAN 28 2016
Clipper system noted on 08z/2am water vapor imagery over Lake
Superior will continue to track eastward today, remaining well to
the northeast of central Illinois. Meanwhile, low clouds in the
wake of the system extending back into the eastern Dakotas will
begin to sink southward. NAM RH profiles appear to be a bit too
aggressive with the southward push, so have trended toward the
slower GFS. Based on current satellite trends and GFS forecast,
have started the day mostly sunny across the board, followed by
increasing clouds from north to south during the late morning into
the afternoon. By the end of the day, skies will be mostly cloudy
across the entire KILX CWA. NAM hints at some light precip skirting
the far NE this afternoon as a trailing trough axis swings through
the area. HRRR is even more bullish, with the latest run showing
precip extending as far west as the I-55 corridor. Think this is
way overdone, so will disregard the HRRR solution. Will however
mention a chance for flurries/sprinkles along/northeast of a
Champaign to Paris line.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 324 AM CST THU JAN 28 2016
Substantial warm-up is still on tap for this weekend as zonal flow
pattern develops across the CONUS and a Pacific-origin airmass
arrives. High temperatures on Friday will be in the lower 40s, then
will climb well into the 50s for both Saturday and Sunday. An
approaching frontal boundary will spread clouds and perhaps a few
rain showers into the area on Sunday: however, weak upper support
and a lack of deep-layer moisture warrants only low chance PoPs.
Big weather story continues to be the development of a major winter
storm early next week. 00z Jan 28 models are in excellent agreement
with the track/timing of this system, and the thermal profiles of
the individual models have also come into better agreement.
GFS/ECMWF/GEM all show surface low pressure developing over the
Texas panhandle Monday evening...then tracking northeastward into
northwest Illinois by Tuesday evening. This particular track will
keep the KILX CWA in the warm sector of the system and lead to
mainly a rain event. Earlier concerns about a potential period of
freezing rain Monday night have been eased with the latest model
run, as surface temps are expected to remain above freezing and the
elevated warm layer achieves max temps of 5-8C by 12z Tue. Have
therefore gone with likely PoPs for rain everywhere Monday night
into Tuesday. With warm/moist air surging northward ahead of the
approaching system, some fairly impressive instability will develop
across the central/eastern CWA Tuesday afternoon. GFS SbCAPEs reach
600-800J/kg while lifted index values drop into the -3 to -5C range.
In addition, 0-6km bulk shear increases to 70-80kt as a strong mid-
level jet develops in advance of the short-wave trough. Given such
strong mid-winter parameters, have added a chance for thunderstorms
to the forecast east of the I-55 corridor on Tuesday.
Both the GFS and ECMWF show the dry slot of the system arriving late
Tuesday afternoon/evening, leading to the end of the significant
precipitation. Based on current projections, it appears rainfall
amounts Monday night through Tuesday will range from 1 to 1.50. As
the low lifts into the Great Lakes, colder air will arrive Tuesday
night and deformation zone precip will arrive from the west.
Thermal profiles are initially warm enough to support rain early
in the evening, but then cool sufficiently for snow Tuesday night
into Wednesday. While the vast majority of the snow will fall
west of the Mississippi River across Iowa/Wisconsin, some light
snow accumulation will be possible across the western half of the
CWA as the precip departs and comes to an end on Wednesday. In
addition, strong winds gusting to at least 30mph and temperatures
falling into the 20s and 30s will make Wednesday a blustery/cold
day.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1120 PM CST WED JAN 27 2016
VFR conditions are expected to hold across the area into the mid
morning hours of Thursday as a weak frontal boundary/surface trof
shifts southeast across the area. Behind the weak front, we look
for another band of MVFR cigs to shift southeast into the TAF area
Thursday morning at PIA and BMI in the 14z-16z time frame, and
from 16z-18z at SPI,DEC and CMI. Bases of the lower cigs will
range from 1500 to 2500 feet with forecast soundings not showing
much if any improvement thru this forecast period. Surface winds
will begin to veer more into a southwest direction overnight with
speeds of 12 to 17 kts and then shift into a west to northwest
direction Thursday morning as the weak frontal system moves through.
Wind speeds will range from 12 to 17 kts with a few gusts around
23 kts at times.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1119 PM CST WED JAN 27 2016
.UPDATE...
ISSUED AT 834 PM CST WED JAN 27 2016
Another fast moving clipper passing well to our north this
evening keeping the more significant precip away from central
Illinois. The latest surface map was showing a trof/wind shift
line over central Iowa which was tracking east towards our area.
Other than some scattered to broken mid level clouds, not much
in the way of sensible weather noted out to our west. The gusty
southerly winds tonight should help keep temperatures on the
mild side for late January before the surface trof shifts through
our area overnight. Have made some minor adjustments to the winds
and evening temperatures, with the rest of the forecast looking
good. Update already sent.
&&
.SHORT TERM...(Tonight)
ISSUED AT 301 PM CST WED JAN 27 2016
Most of the earlier stratocumulus has faded early this afternoon,
with the lingering clouds over east central Illinois showing more of
a diurnal appearance. Mid level clouds quickly streaming toward us
from the northwest, ahead of a trough/warm front the clipper that
will track across the Great Lakes tonight. Temperatures are well
into the 30s this afternoon and were close to 40 in areas west of
Springfield.
Main impact from the trough/front will be with the winds, as its
passage will otherwise only bring clouds with it. Tightening
pressure gradient will cause a period of gusty southwest winds
beginning late afternoon northwest of the Illinois River, and
spreading south of I-70 by early evening. HRRR guidance seems too
high with a period of 40-45 mph gusts this evening, but the LAMP
guidance closer to 25 mph seems more reasonable. Winds will lighten
up a bit overnight as the main trough axis crosses the area.
Temperatures should remain fairly steady in the evening, before
falling off to around 30 degrees in most areas late night.
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 301 PM CST WED JAN 27 2016
Another clipper system near the northern MN and sw Ontario border
will track across the Great Lakes region Thu and drive a frontal
boundary/trof east across IL by Thu afternoon. Added small chances
of light snow or flurries to ne CWA Thu afternoon and also increased
the cloud cover during Thu especially by late morning and afternoon.
Highs Thu in upper 30s to near 40F from I-74 north and lower 40s
south with Lawrenceville near 45F. WSW winds at dawn Thu to veer WNW
Thu afternoon at 10-15 mph and gusts 17-24 mph so a bit breezy Thu.
Weak surface high pressure ridge of 1017 mb moves east from the
Great Plains into IL by dawn Friday and decrease the winds Thu night.
Lows mostly in the mid 20s Thu night, with some upper 20s se of I-
70. High pressure shifts east of IL during Friday with increasing
southerly flow and its back side and a bit milder highs in the low
to mid 40s, mildest from Springfield sw. Partly to mostly sunny
skies Friday with weak upper level ridging into IL by Fri afternoon.
Upper level flow becomes more zonal late this week with milder
Pacific air moving into IL this weekend. SW winds Sat brings highs
to near 50F from I-74 north and mid 50s south of I-70 and sw of
Springfield. Highs mostly in the 50s on Sunday ranging from around
50F nw of IL river to upper 50s in southeast IL. Low pressure
passing north of Lake Superior Saturday to increase clouds northern
CWA while southeast IL enjoys more sunshine through the day Saturday.
More active weather pattern takes shape Sunday-Wednesday as IL gets
established in a sw upper level flow with upper level trof digging
over the Rockies and upper level ridging building near the Atlantic
coast. Above normal temps through Tue then cooling closer to normal
next Wed. Low pressure near the western KS/OK border by sunset Sat
to eject ne into the western Great Lakes by sunset Sunday and pull a
frontal boundary se into central IL Sunday afternoon. This to bring
1st chance of light rain showers and lingering Sunday night
especially over ne and eastern IL Sunday evening. Could see a mix of
precipitation along and north of a Rushville to Bloomington line
after midnight Sunday night but little or no snow accumuation. Still
looks like a lull in rain chances Monday with mainly slight chances
as stronger surface low pressure gets organized over north Texas.
Models bring strong low pressure ne into west central or nw IL Tue
evening and into the western Great Lakes Wed. Central and southeast
IL appear to be mostly in the warm sector with mostly rain chances,
starting to increase from sw to ne during Monday night, with likely
chances Tue and Tue night. A few thunderstorms possible Tue south of
highway 50 in southern IL. Colder air beginning to move in during
Tue night especially after midnight Tue night and Wed to change rain
to snow nw CWA with some accumulations possible mainly nw of the IL
river. Most of area will see a good chance of light snow on Wed as
colder air continues to usher into the area.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1120 PM CST WED JAN 27 2016
VFR conditions are expected to hold across the area into the mid
morning hours of Thursday as a weak frontal boundary/surface trof
shifts southeast across the area. Behind the weak front, we look
for another band of MVFR cigs to shift southeast into the TAF area
Thursday morning at PIA and BMI in the 14z-16z time frame, and
from 16z-18z at SPI,DEC and CMI. Bases of the lower cigs will
range from 1500 to 2500 feet with forecast soundings not showing
much if any improvement thru this forecast period. Surface winds
will begin to veer more into a southwest direction overnight with
speeds of 12 to 17 kts and then shift into a west to northwest
direction Thursday morning as the weak frontal system moves through.
Wind speeds will range from 12 to 17 kts with a few gusts around
23 kts at times.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1131 AM CST THU JAN 28 2016
...AVIATION UPDATE...
.UPDATE...
ISSUED AT 940 AM CST THU JAN 28 2016
CLOUD COVER IS MOVING SOUTH QUICKER THAN FORECAST. AREA RADARS
HAVE AN AREA OF MAINLY SNOW SHOWERS FROM SOUTHEAST MINNESOTA INTO
SOUTHEAST WISCONSIN. EXTRAPOLATION OF THE RADAR RETURNS TAKES A
BULK OF THE THE PRECIPITATION MAINLY INTO SOUTHEAST WISCONSIN AND
NORTHEAST ILLINOIS.
HOWEVER...TRENDS FROM THE RAP SUGGEST THE POTENTIAL FOR DIURNAL
RAIN OR SNOW SHOWERS DEVELOPING AS FAR WEST AS A MANCHESTER IA TO
KEWANEE IL LINE. IF THE PRECIPITATION IS IN THE FORM OF SNOW
SHOWERS...ANY ACCUMULATION SHOULD MELT ON CONTACT WITH THE GROUND.
THE FORECAST HAS BEEN UPDATED TO REFLECT CURRENT TRENDS.
&&
.SYNOPSIS...
ISSUED AT 354 AM CST THU JAN 28 2016
WATER VAPOR IMAGERY SHOWS POTENT SHORTWAVE TROUGH SHIFTING ACROSS THE
GREAT LAKES EARLY THIS AM. IN ITS WAKE... A FEW WEAKER IMPULSES WERE
NOTED ACROSS MN AND WI DIVING S/E ALONG FRONT FLANK OF HIGHLY AMPLIFIED
RIDGE OVER WESTERN NOAM. REGIONAL RADARS SHOW A FEW FLURRIES AND
SNOW SHOWERS ACCOMPANYING THESE DISTURBANCES. MSAS SFC ANALYSIS PLACES
DEEP LOW OF 990 MB OVER LAKE SUPERIOR ATTENDANT TO POTENT GREAT LAKES
SHORTWAVE. COLD FRONT EXTENDS FROM THIS LOW THROUGH NORTHERN MN. WEAK SFC
TROUGH NOTED ACROSS OUR CWA... BUT AIRMASS QUITE DRY AND WEAK FORCING
PRECLUDES ANY CLOUDS ATTIM WITH MAIN CLOUD SHIELD TO OUR NORTH ATTENDANT
TO THE COLD FRONT AND CAA/CYCLONIC FLOW. DESPITE THE GENERALLY CLEAR
SKIES... BRISK WEST/SOUTHWEST WINDS AND PASSING 925 MB THERMAL RIDGE
ARE HELPING TO HOLD TEMPS UP MAINLY IN THE LOWER TO MIDDLE 30S... WHICH
AT OR ABOVE NORMAL HIGHS FOR THE DATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CST THU JAN 28 2016
MIXING AND STRENGTHENING CYCLONIC FLOW WILL BRING SHIFT TO NORTHWEST WINDS
THIS AM... WHICH COUPLED WITH TIGHTENING PRESSURE GRADIENT WILL LEAD TO
BRISK CONDITIONS WITH WINDS GENERALLY BECOMING SUSTAINED AT 14-20 KTS
GUSTING TO AROUND 25-28 KTS PER WIND PROFILES THROUGH AND ATOP THE MIXED
LAYER. THIS FLOW WILL SHUTTLE IN CLOUDS CURRENTLY TO OUR NORTH... THUS
SUNNY TO START THEN LOOK FOR SKIES TO BECOME MOSTLY CLOUDY. FOR HIGHS TDY
GENERALLY LEANED AT OR A BIT ABOVE WARMEST GUIDANCE PER DEEP MIXING ALONG
WITH SUNNY AND MILD START. BEFORE CLOUDS ARRIVE ANTICIPATE TEMPS CLIMBING
MAINLY INTO THE UPPER 30S TO LOWER 40S...EXCEPT FAR NORTH WHERE MAY REMAIN
IN MID 30S AS CLOUDS ARRIVE THERE FIRST. WHEN THE CLOUDS DO ARRIVE THEY
WILL SEAL OFF TEMP RISE AND WITH DEVELOPING CAA AT 925 MB WILL LIKELY
SEE READINGS HOLD STEADY IF NOT SLIP BACK A FEW DEGS. KEPT SMALL PRECIP
CHCS FOR THIS AFTN MAINLY FOR PORTIONS OF FAR EASTERN IA AND NORTHWEST IL
BEING IN CLOSER PROXIMITY TO WEAKER UPPER LEVEL IMPULSES. WEAK LIFT BUT
WHEN COMBINED WITH VERY STEEP LOW LEVEL LAPSE RATES MAY LEAD TO SHALLOW
WEAK CONVECTION... THUS 15-20 POPS FOR ISOLD SHOWERS WITH THERMAL PARAMETERS
SUGGESTING RAIN/SNOW AND EVEN PERHAPS SLEET.
TONIGHT...ANTICIPATE DECREASING LOWER CLOUDS IN WAKE OF DEPARTING COLD FRONT
WITH EVENTUALLY JUST SOME CIRRUS SPILLING DOWN THE UPPER RIDGE FOR PARTLY
CLOUDY SKIES. SFC RIDGE WILL BUILD IN OVERNIGHT WITH DIMINISHING WIND.
GIVEN THE ANTICIPATION OF BROKEN CIRRUS COVERAGE TEMPERED MINS TO WARM SIDE
OF GUIDANCE BLEND WITH A GENERAL RANGE FROM THE UPPER TEENS TO MID 20S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 354 AM CST THU JAN 28 2016
FRIDAY THROUGH SUNDAY...FRIDAY STILL LOOKING LIKE AN INCREASING WARM
AIR ADVECTION DAY AHEAD OF ANOTHER CLIPPER LOW RIPPLING OUT OF
CENTRAL CANADA AND INTO THE NORTHWESTERN GRT LKS. POSSIBLE CLOUD
COVER AND A SHARPENING INVERSION ALOFT CENTERED ON THE H85 MB LEVEL
MAY LIMIT THE PRE-SYSTEM WARM UP POTENTIAL AND THE LATEST TEMP
GUIDANCE HAS BACKED OFF SOME...WILL ADVERTISE LOW TO MID 30S IN THE
FAR NORTHEAST TO THE MID 40S IN THE SOUTHWEST. RATHER BRISK
SOUTHWEST SFC WINDS FRI NIGHT AS WELL AS CLOUD COVER TO MAKE FOR A
STEADY TEMP TREND INTO SAT MORNING WITH MINIMAL DROP OFF AFTER
SUNSET. WILL KEEP THE FCST DRY FOR FRI NIGHT...BUT INCREASING
SIGNALS OF SOME LIGHT WAA TYPE PRECIP MAINLY IN THE FORM OF
SPRINKLES OR SPOTTY LIGHT RAIN MAY OCCUR FRI EVENING AND INTO THE
OVERNIGHT.
BACKING LLVL FLOW UNDER FLATTENING/INCREASINGLY ZONAL FLOW PATTERN
ACRS MUCH OF THE CONUS ON SAT TO TRANSLATE INTO AN UNSEASONABLY MILD
DAY. AGAIN CLOUD COVER AND VERTICAL MIXING LIMITING INVERSION
OVERHEAD TO SUPPRESS TRUE WARM UP POTENTIAL...BUT AT LEAST SOME
PARTIAL INSOLATION AND MIXING UP TO H925 MB/INVERSION BASE MAKE FOR
HIGHS WELL UP IN THE 40S FOR MUCH OF THE LOCAL FCST AREA WITH A 50
POSSIBLE SOUTH OF I80. A FRONTAL SYSTEM SAGGING INTO THE AREA FROM
THE WEST OFF ANOTHER WAVE ROLLING ALONG ACTIVE CLIPPER TRACK ALONG
THE U.S./CANADIAN BORDER...MAY BE A FOCUS FOR SOME LIGHT RAIN LATE
SAT NIGHT INTO EARLY SUNDAY MORNING MAINLY ACRS THE WESTERN/
NORTHWESTERN CWA. SFC TEMPS CURRENTLY LOOK TO BE MARGINAL FOR ANY
TYPE OF FREEZING RAIN OR DRIZZLE THREAT. SFC WINDS GOING LIGHT
CONVERGENT IN VCNTY OF THE BOUNDARY MAY INDUCE SOME AREAS OF FOG
HOWEVER. ON SUNDAY...THE FRONT SLOWS BUT CONTINUES TO SAG SOUTHEAST
THROUGH THE AREA FOR A ONGOING LIGHT PRECIP FOCUS AGAIN MAINLY IN
THE FORM OF LIGHT RAIN/SPRINKLES OR DRIZZLE IF CLOUD CEILINGS ARE
LOW ENOUGH. AS THE FRONT STALLS OUT TO THE SOUTH OF THE AREA ALIGNED
PARALLEL TO ORGANIZING WEST-SOUTHWESTERLIES FROM THE CENTRAL
PLAINS...TO THE SOUTHEASTERN GRT LKS/EASTERN OH RVR VALLEY
REGIONS... A LEAD WAVE PULSING ALONG THE BAROCLINIC RIBBON MAY
INDUCE AN ISENTROPIC LIFT PRECIP EVENT SUNDAY NIGHT ACRS THE
SOUTHEASTERN HALF OF THE CWA. THE SOUTHERN EXTENT OF THIS PRECIP
SHOULD REMAIN LIGHT RAIN INTO EARLY MON MORNING...BUT FURTHER TO THE
NORTH IN DEEPENING LLVL NORTHERLY FLOW/LOWERING WBZS A WINTRY MIX
MAY BE MORE IN LINE.
MONDAY THROUGH NEXT WEDNESDAY...ASSESSING THE LATEST SUITE OF 00Z
MEDIUM RANGE MODEL RUNS IN HANDLING THE NOW WELL ADVERTISED LOW
PRESSURE STORM SYSTEM THAT MAY IMPACT THE UPPER MIDWEST EARLY NEXT
WEEK...RUN-TO-RUN VARIATIONS/LACK OF CONSISTENCY EXPECTEDLY
CONTINUE. SEVERAL OF THE 00Z SOLUTIONS ARE NOT QUITE AS DEEP WITH
THE LLVL CYCLONE...HAVE TRENDED BACK FURTHER TO THE NORTHWEST SOME
WITH THE LOW TO MID LEVEL LOW TRACK...AND SPED UP THE LEAD PRECIP
SHIELD ACRS THE REGION BY LATE MON AFTERNOON AND ESPECIALLY MON
NIGHT. THE GENERAL ENSEMBLE MAIN SFC LOW TRACK CURRENTLY IS FROM
WEST CENTRAL TO SOUTHWESTERN MO LATE TUE MORNING...ACRS THE EAST
CENTRAL CWA TO JUST SOUTHWEST OF CHICAGO BY 00Z WED...AND THEN
ROLLING INTO WEST CENTRAL LOWER MI BY MIDNIGHT TUE NIGHT. THIS PATH
AS WELL AS THE MID LEVEL LOW TRACK CURRENTLY INDICATED WOULD PLACE
THE HEAVIEST SNOW TOTALS GENERATED BY THE MAIN SYSTEM...TO THE WEST
AND THE NORTHWEST OF THE DVN CWA. BUT BACK TO MON NIGHT WITH THE
INITIAL PRECIP SURGE AHEAD OF THE MAIN SYSTEM...POTENTIAL OF A WINTRY
MIX OF FREEZING RAIN/SLEET/SNOW OR INITIAL STARTING OUT AS
ACCUMULATING SNOW BEFORE THE MIX STARTS LATE MON NIGHT. PORTIONS OF
THE AREA MAY BE MAINLY RAIN ON TUE WITH A STRONG ENOUGH WARM
DRAW...BUT THEN THE IN-WRAPPING LLVL COLD CONVEYOR AS WELL AS ROBUST
DYNAMICAL COOLING COULD HASTEN A SWITCH OVER TO ACCUMULATING SNOW
LATE IN THE DAY AND ESPECIALLY TUE EVENING WITH WESTERN TO
NORTHWESTERN CWA AREAS STILL OPEN TO DECENT ACCUMULATIONS.
WITH ONGOING UNCERTAINTIES AND MODEL RUN ADJUSTMENTS STILL EXPECTED
OVER THE NEXT 2-3 DAYS UNTIL THE PACIFIC WAVE ENERGY GETS BETTER
SAMPLED...WILL JUST ADVERTISE A MIX-GOING-INTO-SNOW GENERAL SCENARIO
WITH LIKELY POPS FOR NOW FOR THE PRIME WINDOW OF MON NIGHT THROUGH
WED AM. WHATEVER TRACK THE SYSTEM TAKES...IF THE CURRENT MODELS ARE
CLOSE TO THE DEPTH OF THE LOW THERE MAY BE STRONG WINDS WRAPPING IN
BEHIND IT ALONG WITH STRONG COLD AIR ADVECTION THAT COULD COMBINE
WITH LINGERING SNOWFALL UNDER THE DEPARTING UPPER LEVEL LOW FOR
CONTINUED WINTER WX IMPACTS. CURRENT MODEL RUNS SUGGEST THIS TO BE
WED INTO WED NIGHT. MUCH COLDER AFTER THE SYSTEM FOR MID TO LATE
NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1126 AM CST THU JAN 28 2016
VFR WITH AREAS OF MVFR CONDITIONS WILL BE SEEN ACROSS EASTERN IOWA
AND NORTHERN ILLINOIS THROUGH 00Z/29. ISOLATED RAIN/SNOW SHOWERS
MAY AFFECT KDBQ/KMLI THROUGH 23Z/28 SO A VCSH WAS INCLUDED IN THE
18Z TAFS. IF A STRONGER SHOWER HITS KDBQ/KMLI THEN A BRIEF PERIOD
OF MVFR/IFR CONDITIONS IS POSSIBLE. AFT 00Z/29 LOW CLOUDS WILL
MOVE OUT AS HIGH PRESSURE BUILDS INTO THE MIDWEST LEAVING VFR
CONDITIONS. THERE MAY OR MAY NOT BE AREAS OF MVFR VSBY PRIOR TO
SUNRISE FRIDAY DUE TO THE LIGHT WINDS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...05
SHORT TERM...05
LONG TERM...12
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
952 AM CST THU JAN 28 2016
.UPDATE...
ISSUED AT 940 AM CST THU JAN 28 2016
CLOUD COVER IS MOVING SOUTH QUICKER THAN FORECAST. AREA RADARS
HAVE AN AREA OF MAINLY SNOW SHOWERS FROM SOUTHEAST MINNESOTA INTO
SOUTHEAST WISCONSIN. EXTRAPOLATION OF THE RADAR RETURNS TAKES A
BULK OF THE THE PRECIPITATION MAINLY INTO SOUTHEAST WISCONSIN AND
NORTHEAST ILLINOIS.
HOWEVER...TRENDS FROM THE RAP SUGGEST THE POTENTIAL FOR DIURNAL
RAIN OR SNOW SHOWERS DEVELOPING AS FAR WEST AS A MANCHESTER IA TO
KEWANEE IL LINE. IF THE PRECIPITATION IS IN THE FORM OF SNOW
SHOWERS...ANY ACCUMULATION SHOULD MELT ON CONTACT WITH THE GROUND.
THE FORECAST HAS BEEN UPDATED TO REFLECT CURRENT TRENDS.
&&
.SYNOPSIS...
ISSUED AT 354 AM CST THU JAN 28 2016
WATER VAPOR IMAGERY SHOWS POTENT SHORTWAVE TROUGH SHIFTING ACROSS THE
GREAT LAKES EARLY THIS AM. IN ITS WAKE... A FEW WEAKER IMPULSES WERE
NOTED ACROSS MN AND WI DIVING S/E ALONG FRONT FLANK OF HIGHLY AMPLIFIED
RIDGE OVER WESTERN NOAM. REGIONAL RADARS SHOW A FEW FLURRIES AND
SNOW SHOWERS ACCOMPANYING THESE DISTURBANCES. MSAS SFC ANALYSIS PLACES
DEEP LOW OF 990 MB OVER LAKE SUPERIOR ATTENDANT TO POTENT GREAT LAKES
SHORTWAVE. COLD FRONT EXTENDS FROM THIS LOW THROUGH NORTHERN MN. WEAK SFC
TROUGH NOTED ACROSS OUR CWA... BUT AIRMASS QUITE DRY AND WEAK FORCING
PRECLUDES ANY CLOUDS ATTIM WITH MAIN CLOUD SHIELD TO OUR NORTH ATTENDANT
TO THE COLD FRONT AND CAA/CYCLONIC FLOW. DESPITE THE GENERALLY CLEAR
SKIES... BRISK WEST/SOUTHWEST WINDS AND PASSING 925 MB THERMAL RIDGE
ARE HELPING TO HOLD TEMPS UP MAINLY IN THE LOWER TO MIDDLE 30S... WHICH
AT OR ABOVE NORMAL HIGHS FOR THE DATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CST THU JAN 28 2016
MIXING AND STRENGTHENING CYCLONIC FLOW WILL BRING SHIFT TO NORTHWEST WINDS
THIS AM... WHICH COUPLED WITH TIGHTENING PRESSURE GRADIENT WILL LEAD TO
BRISK CONDITIONS WITH WINDS GENERALLY BECOMING SUSTAINED AT 14-20 KTS
GUSTING TO AROUND 25-28 KTS PER WIND PROFILES THROUGH AND ATOP THE MIXED
LAYER. THIS FLOW WILL SHUTTLE IN CLOUDS CURRENTLY TO OUR NORTH... THUS
SUNNY TO START THEN LOOK FOR SKIES TO BECOME MOSTLY CLOUDY. FOR HIGHS TDY
GENERALLY LEANED AT OR A BIT ABOVE WARMEST GUIDANCE PER DEEP MIXING ALONG
WITH SUNNY AND MILD START. BEFORE CLOUDS ARRIVE ANTICIPATE TEMPS CLIMBING
MAINLY INTO THE UPPER 30S TO LOWER 40S...EXCEPT FAR NORTH WHERE MAY REMAIN
IN MID 30S AS CLOUDS ARRIVE THERE FIRST. WHEN THE CLOUDS DO ARRIVE THEY
WILL SEAL OFF TEMP RISE AND WITH DEVELOPING CAA AT 925 MB WILL LIKELY
SEE READINGS HOLD STEADY IF NOT SLIP BACK A FEW DEGS. KEPT SMALL PRECIP
CHCS FOR THIS AFTN MAINLY FOR PORTIONS OF FAR EASTERN IA AND NORTHWEST IL
BEING IN CLOSER PROXIMITY TO WEAKER UPPER LEVEL IMPULSES. WEAK LIFT BUT
WHEN COMBINED WITH VERY STEEP LOW LEVEL LAPSE RATES MAY LEAD TO SHALLOW
WEAK CONVECTION... THUS 15-20 POPS FOR ISOLD SHOWERS WITH THERMAL PARAMETERS
SUGGESTING RAIN/SNOW AND EVEN PERHAPS SLEET.
TONIGHT...ANTICIPATE DECREASING LOWER CLOUDS IN WAKE OF DEPARTING COLD FRONT
WITH EVENTUALLY JUST SOME CIRRUS SPILLING DOWN THE UPPER RIDGE FOR PARTLY
CLOUDY SKIES. SFC RIDGE WILL BUILD IN OVERNIGHT WITH DIMINISHING WIND.
GIVEN THE ANTICIPATION OF BROKEN CIRRUS COVERAGE TEMPERED MINS TO WARM SIDE
OF GUIDANCE BLEND WITH A GENERAL RANGE FROM THE UPPER TEENS TO MID 20S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 354 AM CST THU JAN 28 2016
FRIDAY THROUGH SUNDAY...FRIDAY STILL LOOKING LIKE AN INCREASING WARM
AIR ADVECTION DAY AHEAD OF ANOTHER CLIPPER LOW RIPPLING OUT OF
CENTRAL CANADA AND INTO THE NORTHWESTERN GRT LKS. POSSIBLE CLOUD
COVER AND A SHARPENING INVERSION ALOFT CENTERED ON THE H85 MB LEVEL
MAY LIMIT THE PRE-SYSTEM WARM UP POTENTIAL AND THE LATEST TEMP
GUIDANCE HAS BACKED OFF SOME...WILL ADVERTISE LOW TO MID 30S IN THE
FAR NORTHEAST TO THE MID 40S IN THE SOUTHWEST. RATHER BRISK
SOUTHWEST SFC WINDS FRI NIGHT AS WELL AS CLOUD COVER TO MAKE FOR A
STEADY TEMP TREND INTO SAT MORNING WITH MINIMAL DROP OFF AFTER
SUNSET. WILL KEEP THE FCST DRY FOR FRI NIGHT...BUT INCREASING
SIGNALS OF SOME LIGHT WAA TYPE PRECIP MAINLY IN THE FORM OF
SPRINKLES OR SPOTTY LIGHT RAIN MAY OCCUR FRI EVENING AND INTO THE
OVERNIGHT.
BACKING LLVL FLOW UNDER FLATTENING/INCREASINGLY ZONAL FLOW PATTERN
ACRS MUCH OF THE CONUS ON SAT TO TRANSLATE INTO AN UNSEASONABLY MILD
DAY. AGAIN CLOUD COVER AND VERTICAL MIXING LIMITING INVERSION
OVERHEAD TO SUPPRESS TRUE WARM UP POTENTIAL...BUT AT LEAST SOME
PARTIAL INSOLATION AND MIXING UP TO H925 MB/INVERSION BASE MAKE FOR
HIGHS WELL UP IN THE 40S FOR MUCH OF THE LOCAL FCST AREA WITH A 50
POSSIBLE SOUTH OF I80. A FRONTAL SYSTEM SAGGING INTO THE AREA FROM
THE WEST OFF ANOTHER WAVE ROLLING ALONG ACTIVE CLIPPER TRACK ALONG
THE U.S./CANADIAN BORDER...MAY BE A FOCUS FOR SOME LIGHT RAIN LATE
SAT NIGHT INTO EARLY SUNDAY MORNING MAINLY ACRS THE WESTERN/
NORTHWESTERN CWA. SFC TEMPS CURRENTLY LOOK TO BE MARGINAL FOR ANY
TYPE OF FREEZING RAIN OR DRIZZLE THREAT. SFC WINDS GOING LIGHT
CONVERGENT IN VCNTY OF THE BOUNDARY MAY INDUCE SOME AREAS OF FOG
HOWEVER. ON SUNDAY...THE FRONT SLOWS BUT CONTINUES TO SAG SOUTHEAST
THROUGH THE AREA FOR A ONGOING LIGHT PRECIP FOCUS AGAIN MAINLY IN
THE FORM OF LIGHT RAIN/SPRINKLES OR DRIZZLE IF CLOUD CEILINGS ARE
LOW ENOUGH. AS THE FRONT STALLS OUT TO THE SOUTH OF THE AREA ALIGNED
PARALLEL TO ORGANIZING WEST-SOUTHWESTERLIES FROM THE CENTRAL
PLAINS...TO THE SOUTHEASTERN GRT LKS/EASTERN OH RVR VALLEY
REGIONS... A LEAD WAVE PULSING ALONG THE BAROCLINIC RIBBON MAY
INDUCE AN ISENTROPIC LIFT PRECIP EVENT SUNDAY NIGHT ACRS THE
SOUTHEASTERN HALF OF THE CWA. THE SOUTHERN EXTENT OF THIS PRECIP
SHOULD REMAIN LIGHT RAIN INTO EARLY MON MORNING...BUT FURTHER TO THE
NORTH IN DEEPENING LLVL NORTHERLY FLOW/LOWERING WBZS A WINTRY MIX
MAY BE MORE IN LINE.
MONDAY THROUGH NEXT WEDNESDAY...ASSESSING THE LATEST SUITE OF 00Z
MEDIUM RANGE MODEL RUNS IN HANDLING THE NOW WELL ADVERTISED LOW
PRESSURE STORM SYSTEM THAT MAY IMPACT THE UPPER MIDWEST EARLY NEXT
WEEK...RUN-TO-RUN VARIATIONS/LACK OF CONSISTENCY EXPECTEDLY
CONTINUE. SEVERAL OF THE 00Z SOLUTIONS ARE NOT QUITE AS DEEP WITH
THE LLVL CYCLONE...HAVE TRENDED BACK FURTHER TO THE NORTHWEST SOME
WITH THE LOW TO MID LEVEL LOW TRACK...AND SPED UP THE LEAD PRECIP
SHIELD ACRS THE REGION BY LATE MON AFTERNOON AND ESPECIALLY MON
NIGHT. THE GENERAL ENSEMBLE MAIN SFC LOW TRACK CURRENTLY IS FROM
WEST CENTRAL TO SOUTHWESTERN MO LATE TUE MORNING...ACRS THE EAST
CENTRAL CWA TO JUST SOUTHWEST OF CHICAGO BY 00Z WED...AND THEN
ROLLING INTO WEST CENTRAL LOWER MI BY MIDNIGHT TUE NIGHT. THIS PATH
AS WELL AS THE MID LEVEL LOW TRACK CURRENTLY INDICATED WOULD PLACE
THE HEAVIEST SNOW TOTALS GENERATED BY THE MAIN SYSTEM...TO THE WEST
AND THE NORTHWEST OF THE DVN CWA. BUT BACK TO MON NIGHT WITH THE
INITIAL PRECIP SURGE AHEAD OF THE MAIN SYSTEM...POTENTIAL OF A WINTRY
MIX OF FREEZING RAIN/SLEET/SNOW OR INITIAL STARTING OUT AS
ACCUMULATING SNOW BEFORE THE MIX STARTS LATE MON NIGHT. PORTIONS OF
THE AREA MAY BE MAINLY RAIN ON TUE WITH A STRONG ENOUGH WARM
DRAW...BUT THEN THE IN-WRAPPING LLVL COLD CONVEYOR AS WELL AS ROBUST
DYNAMICAL COOLING COULD HASTEN A SWITCH OVER TO ACCUMULATING SNOW
LATE IN THE DAY AND ESPECIALLY TUE EVENING WITH WESTERN TO
NORTHWESTERN CWA AREAS STILL OPEN TO DECENT ACCUMULATIONS.
WITH ONGOING UNCERTAINTIES AND MODEL RUN ADJUSTMENTS STILL EXPECTED
OVER THE NEXT 2-3 DAYS UNTIL THE PACIFIC WAVE ENERGY GETS BETTER
SAMPLED...WILL JUST ADVERTISE A MIX-GOING-INTO-SNOW GENERAL SCENARIO
WITH LIKELY POPS FOR NOW FOR THE PRIME WINDOW OF MON NIGHT THROUGH
WED AM. WHATEVER TRACK THE SYSTEM TAKES...IF THE CURRENT MODELS ARE
CLOSE TO THE DEPTH OF THE LOW THERE MAY BE STRONG WINDS WRAPPING IN
BEHIND IT ALONG WITH STRONG COLD AIR ADVECTION THAT COULD COMBINE
WITH LINGERING SNOWFALL UNDER THE DEPARTING UPPER LEVEL LOW FOR
CONTINUED WINTER WX IMPACTS. CURRENT MODEL RUNS SUGGEST THIS TO BE
WED INTO WED NIGHT. MUCH COLDER AFTER THE SYSTEM FOR MID TO LATE
NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 547 AM CST THU JAN 28 2016
WEST WINDS 10-15 KTS WILL TURN GUSTY FROM THE NORTHWEST AT 15-25
KTS LATER THIS AM THROUGH PM. STRATUS WILL OVERSPREAD THE
TERMINALS THIS AM THROUGH MIDDAY WITH CIGS MAINLY LOWER VFR TO
HIGHER MVFR RANGE. VERY STEEP LAPSE RATES AND AN UPPER LEVEL
DISTURBANCE MAY BRING A FEW RAIN OR SNOW SHOWERS TO FAR EASTERN IA
AND NORTHWEST IL... AND HAVE GONE WITH VCSH WORDING AT DBQ AND MLI.
TONIGHT...A SFC HIGH PRESSURE RIDGE WILL BUILD IN BRINGING VFR
CONDITIONS AND DIMINISHING WINDS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...05
SHORT TERM...05
LONG TERM...12
AVIATION...05
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1047 AM MST THU JAN 28 2016
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 225 AM MST THU JAN 28 2016
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDING ACROSS
THE WESTERN US EXTENDING NORTH ACROSS SOUTHWEST CANADA. NW FLOW IS
IN PLACE ACROSS THE PLAINS WITH RISING HEIGHTS ACROSS THE CENTRAL
ROCKIES. AT THE SURFACE HIGH PRESSURE IS IN PLACE ALONG THE
COLORADO/KANSAS STATE LINE WITH WEAK LEE TROUGH JUST WEST OF OUR CWA.
TODAY-SATURDAY...UPPER LEVEL RIDGING WILL MOVE ACROSS THE PLAINS
EVENTUALLY TRANSITIONING TOWARDS A QUASI-ZONAL WESTERLY PATTERN WITH
THE MAIN STORM TRACK NORTH OF OUR CWA AT LEAST THROUGH THURSDAY
NIGHT. THIS PATTERN WILL CONTINUE TO SUPPORT DRY CONDITIONS AND ABOVE
NORMAL TEMPERATURES AROUND 60...POSSIBLY MID 60S OVER PARTS OF THE
REGION THROUGH SATURDAY. BY FRIDAY/FRIDAY NIGHT A SHORTWAVE MOVING
THROUGH THE PLAINS WILL KICK A WEAK COLD FRONT SOUTH TOWARDS OUR CWA
WHICH COULD HELP INCREASE WINDS AND COMPLICATE HIGH TEMPERATURES
ACROSS THE NORTHERN PART OF THE FORECAST AREA. SINCE CAA IS NOT
PARTICULARLY STRONG WITH THIS HIGHS SHOULD STILL BE ABOVE NORMAL.
SATURDAY NIGHT...AS A TROUGH BEGINS TO BUILD OVER THE WESTERN US
HEIGHTS WILL FALL ACROSS THE NORTHERN PLAINS AND THE NORTHERN STORM
TRACK WILL SHIFT BACK TOWARDS OUR CWA. A STRONGER COLD FRONT WILL
DROP SOUTH OVER OUR REGION AND MID LEVEL FRONTOGENESIS BEHIND THIS
FRONT WILL COMBINE WITH INCREASING MOISTURE ADVECTION TO SUPPORT
POSSIBLE RAIN/SNOW FROM I-70 NORTH. STRONGEST PRECIP SIGNAL/BEST
MEASURABLE CHANCES APPEARS TO BE ALONG THE NEBRASKA STATE LINE.
PRECIP WOULD BE LIGHT IN NATURE WITH ON A DUSTING OF SNOW POSSIBLE
AFTER MIDNIGHT.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 225 AM MST THU JAN 28 2016
WESTERLY FLOW WILL CONTINUE SUNDAY AHEAD OF A TROUGH THAT IS PROGGED
TO MOVE INTO THE CENTRAL ROCKIES MONDAY. THE LOW IS FORECAST TO
MOVE INTO THE OKLAHOMA PANHANDLE MONDAY NIGHT AND INTO CENTRAL
KANSAS TUESDAY. BY TUESDAY NIGHT THE LOW SHOULD BE OVER IOWA.
NORTHWEST FLOW WILL BE ACROSS THE CENTRAL PLAINS WEDNESDAY. SURFACE
HIGH PRESSURE WILL BUILD INTO THE CENTRAL PLAINS SUNDAY/SUNDAY
NIGHT. A SURFACE LOW WILL MOVE INTO OKLAHOMA PANHANDLE MONDAY AND
THEN SHIFT EAST INTO EASTERN KANSAS TUESDAY. HIGH PRESSURE WILL
MOVE INTO WESTERN KANSAS WEDNESDAY.
THE GFS AND ECMWF BRING THE NEXT SYSTEM ACROSS THE SAME GENERAL
TRACK THROUGH THE OKLAHOMA PANHANDLE. HOWEVER THE GFS HAS
SIGNIFICANTLY HIGHER AMOUNTS WHICH ARE SUSPECT. THE RIDGE EAST OF
THE LOW IS LOW AMPLITUDE WHICH SHOULD ALLOW EASTWARD PROGRESSION
RATHER THAN NORTHEAST MOVEMENT AS IT AFFECTS THE FA. BOTH MODELS
SHOW GOOD MOISTURE WITH NO DRY SLOT CUTTING OFF SNOW PRODUCTION.
SINCE THE SYSTEM IS STILL NOT ONSHORE WILL HOLD OFF MAKING ANY BOLD
PREDICTIONS. THE MAIN SNOW EVENT SHOULD BEGIN OVER MOST OF THE FA
MONDAY AND THEN TAPER OFF TUESDAY EVENING. FOR NOW...WINDS ON TUESDAY
WILL LIKELY PRODUCE A POTENTIAL FOR HAZARDOUS DRIVING CONDITIONS
WITH SNOW ON THE GROUND.
MAX TEMPERATURES WILL GO INTO A COOLING TREND WITH 40 TO 46 SUNDAY
COOLING INTO THE UPPER 20S AND 30S MONDAY THROUGH WEDNESDAY. MIN
TEMPERATURES SUNDAY NIGHT SHOULD RANGE FROM THE LOWER TO UPPER 20S
WITH LOWS IN THE TEENS MONDAY NIGHT THROUGH WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1045 AM MST THU JAN 28 2016
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. BREEZY WINDS WILL
LIGHTEN DURING THE EARLY AFTERNOON. LIGHT WINDS TONIGHT WILL SHIFT
FROM THE WEST TO THE SOUTHWEST THEN BACK TO THE WEST BY LATE
MORNING FRIDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
427 AM MST THU JAN 28 2016
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 225 AM MST THU JAN 28 2016
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDING ACROSS
THE WESTERN US EXTENDING NORTH ACROSS SOUTHWEST CANADA. NW FLOW IS
IN PLACE ACROSS THE PLAINS WITH RISING HEIGHTS ACROSS THE CENTRAL
ROCKIES. AT THE SURFACE HIGH PRESSURE IS IN PLACE ALONG THE
COLORADO/KANSAS STATE LINE WITH WEAK LEE TROUGH JUST WEST OF OUR CWA.
TODAY-SATURDAY...UPPER LEVEL RIDGING WILL MOVE ACROSS THE PLAINS
EVENTUALLY TRANSITIONING TOWARDS A QUASI-ZONAL WESTERLY PATTERN WITH
THE MAIN STORM TRACK NORTH OF OUR CWA AT LEAST THROUGH THURSDAY
NIGHT. THIS PATTERN WILL CONTINUE TO SUPPORT DRY CONDITIONS AND ABOVE
NORMAL TEMPERATURES AROUND 60...POSSIBLY MID 60S OVER PARTS OF THE
REGION THROUGH SATURDAY. BY FRIDAY/FRIDAY NIGHT A SHORTWAVE MOVING
THROUGH THE PLAINS WILL KICK A WEAK COLD FRONT SOUTH TOWARDS OUR CWA
WHICH COULD HELP INCREASE WINDS AND COMPLICATE HIGH TEMPERATURES
ACROSS THE NORTHERN PART OF THE FORECAST AREA. SINCE CAA IS NOT
PARTICULARLY STRONG WITH THIS HIGHS SHOULD STILL BE ABOVE NORMAL.
SATURDAY NIGHT...AS A TROUGH BEGINS TO BUILD OVER THE WESTERN US
HEIGHTS WILL FALL ACROSS THE NORTHERN PLAINS AND THE NORTHERN STORM
TRACK WILL SHIFT BACK TOWARDS OUR CWA. A STRONGER COLD FRONT WILL
DROP SOUTH OVER OUR REGION AND MID LEVEL FRONTOGENESIS BEHIND THIS
FRONT WILL COMBINE WITH INCREASING MOISTURE ADVECTION TO SUPPORT
POSSIBLE RAIN/SNOW FROM I-70 NORTH. STRONGEST PRECIP SIGNAL/BEST
MEASURABLE CHANCES APPEARS TO BE ALONG THE NEBRASKA STATE LINE.
PRECIP WOULD BE LIGHT IN NATURE WITH ON A DUSTING OF SNOW POSSIBLE
AFTER MIDNIGHT.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 225 AM MST THU JAN 28 2016
WESTERLY FLOW WILL CONTINUE SUNDAY AHEAD OF A TROUGH THAT IS PROGGED
TO MOVE INTO THE CENTRAL ROCKIES MONDAY. THE LOW IS FORECAST TO
MOVE INTO THE OKLAHOMA PANHANDLE MONDAY NIGHT AND INTO CENTRAL
KANSAS TUESDAY. BY TUESDAY NIGHT THE LOW SHOULD BE OVER IOWA.
NORTHWEST FLOW WILL BE ACROSS THE CENTRAL PLAINS WEDNESDAY. SURFACE
HIGH PRESSURE WILL BUILD INTO THE CENTRAL PLAINS SUNDAY/SUNDAY
NIGHT. A SURFACE LOW WILL MOVE INTO OKLAHOMA PANHANDLE MONDAY AND
THEN SHIFT EAST INTO EASTERN KANSAS TUESDAY. HIGH PRESSURE WILL
MOVE INTO WESTERN KANSAS WEDNESDAY.
THE GFS AND ECMWF BRING THE NEXT SYSTEM ACROSS THE SAME GENERAL
TRACK THROUGH THE OKLAHOMA PANHANDLE. HOWEVER THE GFS HAS
SIGNIFICANTLY HIGHER AMOUNTS WHICH ARE SUSPECT. THE RIDGE EAST OF
THE LOW IS LOW AMPLITUDE WHICH SHOULD ALLOW EASTWARD PROGRESSION
RATHER THAN NORTHEAST MOVEMENT AS IT AFFECTS THE FA. BOTH MODELS
SHOW GOOD MOISTURE WITH NO DRY SLOT CUTTING OFF SNOW PRODUCTION.
SINCE THE SYSTEM IS STILL NOT ONSHORE WILL HOLD OFF MAKING ANY BOLD
PREDICTIONS. THE MAIN SNOW EVENT SHOULD BEGIN OVER MOST OF THE FA
MONDAY AND THEN TAPER OFF TUESDAY EVENING. FOR NOW...WINDS ON TUESDAY
WILL LIKELY PRODUCE A POTENTIAL FOR HAZARDOUS DRIVING CONDITIONS
WITH SNOW ON THE GROUND.
MAX TEMPERATURES WILL GO INTO A COOLING TREND WITH 40 TO 46 SUNDAY
COOLING INTO THE UPPER 20S AND 30S MONDAY THROUGH WEDNESDAY. MIN
TEMPERATURES SUNDAY NIGHT SHOULD RANGE FROM THE LOWER TO UPPER 20S
WITH LOWS IN THE TEENS MONDAY NIGHT THROUGH WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 424 AM MST THU JAN 28 2016
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD AT BOTH KMCK
AND KGLD TERMINALS. WESTERLY WINDS WILL INCREASE BY MIDDAY TO
AROUND 12KT WITH GUSTS 15-20KT POSSIBLE IN THE AFTERNOON. WINDS
WILL THEN VEER TO THE SOUTHWEST AND DECREASE BELOW 10KT AFTER
SUNSET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
225 AM MST THU JAN 28 2016
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 225 AM MST THU JAN 28 2016
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDING ACROSS
THE WESTERN US EXTENDING NORTH ACROSS SOUTHWEST CANADA. NW FLOW IS
IN PLACE ACROSS THE PLAINS WITH RISING HEIGHTS ACROSS THE CENTRAL
ROCKIES. AT THE SURFACE HIGH PRESSURE IS IN PLACE ALONG THE
COLORADO/KANSAS STATE LINE WITH WEAK LEE TROUGH JUST WEST OF OUR CWA.
TODAY-SATURDAY...UPPER LEVEL RIDGING WILL MOVE ACROSS THE PLAINS
EVENTUALLY TRANSITIONING TOWARDS A QUASI-ZONAL WESTERLY PATTERN WITH
THE MAIN STORM TRACK NORTH OF OUR CWA AT LEAST THROUGH THURSDAY
NIGHT. THIS PATTERN WILL CONTINUE TO SUPPORT DRY CONDITIONS AND ABOVE
NORMAL TEMPERATURES AROUND 60...POSSIBLY MID 60S OVER PARTS OF THE
REGION THROUGH SATURDAY. BY FRIDAY/FRIDAY NIGHT A SHORTWAVE MOVING
THROUGH THE PLAINS WILL KICK A WEAK COLD FRONT SOUTH TOWARDS OUR CWA
WHICH COULD HELP INCREASE WINDS AND COMPLICATE HIGH TEMPERATURES
ACROSS THE NORTHERN PART OF THE FORECAST AREA. SINCE CAA IS NOT
PARTICULARLY STRONG WITH THIS HIGHS SHOULD STILL BE ABOVE NORMAL.
SATURDAY NIGHT...AS A TROUGH BEGINS TO BUILD OVER THE WESTERN US
HEIGHTS WILL FALL ACROSS THE NORTHERN PLAINS AND THE NORTHERN STORM
TRACK WILL SHIFT BACK TOWARDS OUR CWA. A STRONGER COLD FRONT WILL
DROP SOUTH OVER OUR REGION AND MID LEVEL FRONTOGENESIS BEHIND THIS
FRONT WILL COMBINE WITH INCREASING MOISTURE ADVECTION TO SUPPORT
POSSIBLE RAIN/SNOW FROM I-70 NORTH. STRONGEST PRECIP SIGNAL/BEST
MEASURABLE CHANCES APPEARS TO BE ALONG THE NEBRASKA STATE LINE.
PRECIP WOULD BE LIGHT IN NATURE WITH ON A DUSTING OF SNOW POSSIBLE
AFTER MIDNIGHT.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 225 AM MST THU JAN 28 2016
WESTERLY FLOW WILL CONTINUE SUNDAY AHEAD OF A TROUGH THAT IS PROGGED
TO MOVE INTO THE CENTRAL ROCKIES MONDAY. THE LOW IS FORECAST TO
MOVE INTO THE OKLAHOMA PANHANDLE MONDAY NIGHT AND INTO CENTRAL
KANSAS TUESDAY. BY TUESDAY NIGHT THE LOW SHOULD BE OVER IOWA.
NORTHWEST FLOW WILL BE ACROSS THE CENTRAL PLAINS WEDNESDAY. SURFACE
HIGH PRESSURE WILL BUILD INTO THE CENTRAL PLAINS SUNDAY/SUNDAY
NIGHT. A SURFACE LOW WILL MOVE INTO OKLAHOMA PANHANDLE MONDAY AND
THEN SHIFT EAST INTO EASTERN KANSAS TUESDAY. HIGH PRESSURE WILL
MOVE INTO WESTERN KANSAS WEDNESDAY.
THE GFS AND ECMWF BRING THE NEXT SYSTEM ACROSS THE SAME GENERAL
TRACK THROUGH THE OKLAHOMA PANHANDLE. HOWEVER THE GFS HAS
SIGNIFICANTLY HIGHER AMOUNTS WHICH ARE SUSPECT. THE RIDGE EAST OF
THE LOW IS LOW AMPLITUDE WHICH SHOULD ALLOW EASTWARD PROGRESSION
RATHER THAN NORTHEAST MOVEMENT AS IT AFFECTS THE FA. BOTH MODELS
SHOW GOOD MOISTURE WITH NO DRY SLOT CUTTING OFF SNOW PRODUCTION.
SINCE THE SYSTEM IS STILL NOT ONSHORE WILL HOLD OFF MAKING ANY BOLD
PREDICTIONS. THE MAIN SNOW EVENT SHOULD BEGIN OVER MOST OF THE FA
MONDAY AND THEN TAPER OFF TUESDAY EVENING. FOR NOW...WINDS ON TUESDAY
WILL LIKELY PRODUCE A POTENTIAL FOR HAZARDOUS DRIVING CONDITIONS
WITH SNOW ON THE GROUND.
MAX TEMPERATURES WILL GO INTO A COOLING TREND WITH 40 TO 46 SUNDAY
COOLING INTO THE UPPER 20S AND 30S MONDAY THROUGH WEDNESDAY. MIN
TEMPERATURES SUNDAY NIGHT SHOULD RANGE FROM THE LOWER TO UPPER 20S
WITH LOWS IN THE TEENS MONDAY NIGHT THROUGH WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 920 PM MST WED JAN 27 2016
FOR KGLD AND KMCK...VFR CONDITIONS EXPECTED. WINDS GENERALLY FROM
THE WEST NEAR 10KTS FROM TAF ISSUANCE THROUGH 16Z BEFORE VEERING
TO THE NORTHWEST AND GUSTING NEAR 20KTS FROM 17Z-23Z. FROM 00Z
THROUGH THE REST OF THE TAF PERIOD WINDS BACK TO THE WEST AND
DECREASE IN SPEED TOWARD 6KTS. ANY CLOUDINESS GENERALLY AT THE
CIRRUS LEVEL...EXCEPTION WOULD BE AT KMCK WHERE SOME FAIR WEATHER
CUMULUS CLOUDS POSSIBLE DURING THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...99
AREA FORECAST DISCUSSION
NWS JACKSON KY
1249 AM EST THU JAN 28 2016
.UPDATE...
ISSUED AT 1248 AM EST THU JAN 28 2016
WITH CLEAR SKIES AND A FEW AREAS OF FOG...THE MAIN CONCERN TONIGHT
WILL BE THE DIURNAL TEMPS AND MATCHING THE RIDGE TO VALLEY
TEMPERATURE DIFFERENCES. WILL CONTINUE WITH THE SPS TO HIGHLIGHT
BLACK ICE FROM MELTING SNOW AS TEMPS DROP INTO THE TEENS IN THE
VALLEYS. SOME PATCHY DENSE FOG WILL ALSO BE POSSIBLE. THE
FORECAST REMAINS ON TRACK AND WILL ONLY UPDATE THE GRIDS. A NEW
ZFP WILL NOT BE NEEDED.
UPDATE ISSUED AT 955 PM EST WED JAN 27 2016
DID A QUICK UPDATE TO THE FORECAST MAINLY TO ADD A TOUCH OF FOG
OVER THE DEEPER SNOWPACK AS SEEN IN THE LATEST HRRR AND RUC13.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. ALSO
UPDATED THE HWO TO ADDRESS THE ONGOING BLACK ICE SITUATION AROUND
THE CWA ALONG WITH ISSUING AN SPS THROUGH 9 AM FOR THE SAME.
UPDATE ISSUED AT 755 PM EST WED JAN 27 2016
00Z SFC ANALYSIS SHOWS A NARROW AREA OF HIGH PRESSURE SQUEEZING
THROUGH KENTUCKY THIS EVENING. THIS HAS TEMPORARILY CLEARED THE
SKIES AND COMBINED WITH LIGHT WINDS SHOULD SUPPORT THE DEVELOPMENT
OF A MODERATE RIDGE TO VALLEY TEMPERATURE SPLIT FOR MUCH OF THE
NIGHT. CURRENTLY READINGS VARY FROM THE MID 20S IN THE DEEPER
VALLEYS TO NEAR 30 ON THE RIDGES AND IN THE MORE OPEN TERRAIN.
DEWPOINTS ARE RUNNING IN THE UPPER TEENS TO MID 20S ACROSS THE
REGION. THE SNOWPACK REMAINS AN ISSUE FOR MUCH OF THE CWA ADDING
TO THE CHALLENGE FOR TEMPERATURE FORECASTING OVERNIGHT. IN
ADDITION...THE AREAS WHERE IT IS STILL THICK ENOUGH WILL NEED TO
BE MONITORED FOR THE POTENTIAL OF LOCAL FOG FORMATION AFTER
MIDNIGHT. OTHERWISE...CLEAR SKIES AND COLD CONDITIONS WILL BE THE
RULE WITH REFREEZING ON AREA ROADS AN ONGOING CONCERN THROUGH THE
NIGHT AS TEMPERATURES BOTTOM OUT IN THE UPPER TEENS AND LOW 20S
IN MOST PLACES. HAVE UPDATED THE FORECAST TO REFLECT THESE
TEMPERATURE AND SKY COVER ISSUES...ALONG WITH INCORPORATING THE
LATEST OBS AND TRENDS IN THE NEAR TERM. THESE GRIDS HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 400 PM EST WED JAN 27 2016
LOW STRATUS HAS MIXED OUT THIS AFTERNOON AS TEMPERATURES HAVE
CLIMBED INTO THE MID-UPPER 30S FOR ALL BUT A FEW OF THE HIGHEST
RIDGES ACROSS EASTERN KENTUCKY. SURFACE RIDGING WILL CONTINUE TO
MAINTAIN INFLUENCE ACROSS THE REGION INTO THIS EVENING...KEEPING
WINDS LIGHT AND PROVIDING FOR SOME PATCHY FOG AND LOW STRATUS
ESPECIALLY ACROSS SOME OF THE LOWER VALLEYS TONIGHT AS DRAINAGE/DOWN
VALLEY FLOWS COMMENCE. THIS THREAT WILL SHIFT EAST IN CONJUNCTION
WITH DEPARTING SURFACE RIDGING ALLOWING LIGHT SOUTHWESTERLY WINDS TO
RETURN.
THE BRUNT IF NOT ALL OF THURSDAY SHOULD REMAIN DRY DESPITE THE
PASSAGE OF A LEAD SHORTWAVE TROUGH SWINGING THROUGH FROM HUDSON BAY
THROUGH THE GREAT LAKES. FORCING FROM THIS FEATURE WILL LIKELY
REMAIN TOO FAR NORTH TO PROVIDE FOR MORE THAN AN INCREASE IN MID-
HIGH CLOUDS AS A FORMIDABLE DRY WEDGE OF AIR REMAINS IN PLACE
BETWEEN A SHALLOW SATURATED BOUNDARY LAYER AND 10000-12000 FEET.
A SECOND WAVE WILL SWING THROUGH THURSDAY EVENING AND NIGHT...THIS
TIME WITH A GREATER AMOUNT OF LIFT MAKING IT MUCH FARTHER SOUTH
INTO THE COMMONWEALTH. TEMPERATURES MAKING IT INTO THE 40S
THURSDAY AFTERNOON SHOULD PROMOTE MAINLY RAIN/SPRINKLES AT THE
ONSET OF PRECIPITATION THURSDAY EVENING...BUT COLUMN COOLING AND
WET-BULBING SHOULD PROMOTE A TRANSITION TO LIGHT SNOW
SHOWERS/FLURRIES BY MID EVENING. ANY ACCUMULATIONS WILL REMAIN
LIGHT...WITH PERHAPS UP TO HALF AN INCH FALLING ACROSS THE HIGHER
RIDGES NEAR THE VIRGINIA AND WEST VIRGINIA STATE LINES.
WEST/NORTHWEST WINDS WILL LIKELY SPELL AREAS OF LOW STRATUS INTO
FRIDAY MORNING WITH FOG A LOWER POSSIBILITY GIVEN THE INCREASED
PRESSURE GRADIENT AND 5-10 MPH WINDS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 435 PM EST WED JAN 27 2016
ZONAL FLOW WILL RULE THE CONUS THROUGH THE WEEKEND...BEFORE
THE PATTERN AMPLIFIES ONCE AGAIN INTO THE EARLY AND MIDDLE
PORTION OF NEXT WEEK. THE MODELS ARE IN GOOD AGREEMENT THROUGH THE
FIRST PART OF THE WEEKEND...BUT DETAILS ON THE EVOLVING LONG WAVE
PATTERN INTO NEXT WEEK ARE STILL ALLOWING FOR PLENTY OF
UNCERTAINTY. AS SUCH...CONTINUED TO STICK CLOSE TO THE BLENDED
GUIDANCE.
A FEW SNOW SHOWERS/FLURRIES WILL GRADUALLY COME TO AN END ACROSS
SOUTHEASTERN KENTUCKY FRIDAY MORNING AS HIGH PRESSURE QUICKLY
BUILDS IN AT THE SURFACE AND HEIGHTS RECOVER ALOFT. HIGHS WILL BE
COOLER ON FRIDAY...WITH UPPER 30S TO AROUND 40 COMMON. THE SURFACE
HIGH WILL QUICKLY SCOOT OFF TO THE EAST FRIDAY NIGHT...ALLOWING
FOR A GOOD RIDGE/VALLEY SPLIT AS WARM AIR ADVECTION COMMENCES IN
RETURN FLOW. THE COOLER VALLEYS WILL DIP DOWN INTO THE LOWER
20S...WHILE RIDGES STAY UP IN THE LOWER 30S.
WARMING TEMPERATURES WILL THEN BE THE MAIN STORY HEADING INTO THE
WEEKEND...AS HIGHS RETURN WELL INTO THE 50S...WITH A FEW 60S
POSSIBLE BY SUNDAY. CLOUDS WILL BE ON THE INCREASE BY LATE SUNDAY
AS A COLD FRONT APPROACHES FROM THE NORTHWEST. THE GFS AND ECMWF
CONTINUE TO DISAGREE ON THE EXTENT OF IMPACT FROM THIS ACROSS
EASTERN KENTUCKY BY MONDAY. THE GFS REMAINS MORE AGGRESSIVE WITH
THE PROGRESSION OF THE FRONT AND THE PRECIP INTO OUR AREA...WHILE
THE ECMWF HAS KEPT THE BOUNDARY FROM COMING MUCH FURTHER SOUTHEAST
THAN THE OHIO RIVER. AGAIN...STUCK CLOSE TO A BLEND...KEEPING A
GRADIENT OF HIGHER POPS IN THE NORTHWEST AND LESS IN THE
SOUTHEAST FOR NOW. POPS REALLY RAMP UP TUESDAY INTO TUESDAY NIGHT AS
A STRONG SYSTEM GENS UP ACROSS THE MISSISSIPPI VALLEY AND PIVOTS
OFF TO THE NORTHEAST...REACHING THE GREAT LAKES BY WEDNESDAY. THE
BEST CHANCE POPS LOOK TO BE ON TUESDAY NIGHT...WITH THE BLENDED
GUIDANCE OFFERING LIKELY POPS. SOME SCATTERED SHOWERS MAY LINGER
INTO WEDNESDAY...WITH HIGHS FALLING BACK FROM THE UPPER 50S TO
LOWER 60S TUESDAY...TO THE 40S AND 50S BEHIND THE COLD FRONT ON
WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1248 AM EST THU JAN 28 2016
AN AREA OF SURFACE HIGH PRESSURE WILL CONTINUE TO KEEP EASTERN
KENTUCKY UNDER CLEAR SKIES THROUGH THE REST OF THE NIGHT.
SUBSIDENCE OVERHEAD ALONG WITH LEFTOVER SNOWPACK AND CALM WINDS
MAY CREATE SOME PATCHY FOG DEVELOPMENT. THE MOST LIKELY LOCATION
FOR THIS WILL BE SJS WITH PLENTY OF LEFTOVER SNOW. LOCAL EFFECTS
MAY ALSO LEAVE FOR SOME FOG DEVELOPMENT AT SME AS WELL. FOR THE
MOST PART THOUGH...VFR CONDITIONS WILL PREVAIL. THROUGH THE DAY
TODAY...SOUTHWEST WINDS WILL ENGAGE AHEAD OF AN APPROACHING COLD
FRONT WITH SOME GUSTS TO 20 KNOTS. CLOUDS COVER WILL ALSO BE ON
THE INCREASE WITH MID AND UPPER LEVEL CIGS BY THE END OF THE DAY.
EXPECT SOME MVFR AND EVEN IFR CIGS AFTER 00Z AS THE IMPACTS FROM
THIS FRONT WILL MOVE INTO THE AREA TOWARD THE END OF THE TAF
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GUSEMAN
LONG TERM...GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
718 PM EST FRI JAN 29 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 412 PM EST FRI JAN 29 2016
...WINTRY MIX OF PRECIPITATION TONIGHT...
STRONG SPLIT FLOW PATTERN ALOFT ACROSS THE CONUS TODAY. DECENT JET
IS PRESENT OVER UPPER LAKES IN NW FLOW ALOFT. RIDGING HAS MOVED FM
CNTRL CONUS TO WESTERN GREAT LAKES BUT STRONG SHORTWAVE TROUGH WITH
ASSOCIATED SFC LOW IS OVER CENTRAL MANITOBA. WARM AIR ADVECTION
ALOFT TO THE SOUTH OF THAT SYSTEM WITH H85 TEMPS AT 12Z +10C AT ABR
AND -6C AT INL. SMALLER SHORTWAVE ON SOUTH EDGE OF TROUGH UPSTREAM
OVER DAKOTAS MOVES FM NORTHWEST MN THIS EVENING THEN ACROSS UPR
MICHIGAN AND LK SUPERIOR LATE TONIGHT AND OVER QUEBEC BY MIDDAY
SATURDAY. ASSOCIATED SFC LOW FOLLOWS SUIT...TRACKING ACROSS ONTARIO
AND PUSHING A WARM FRONT OVER UPPER LAKES. PRECIP FORMING OVER MN IS
TIED TO THE SHORTWAVE AND STRONG WARM AIR ADVECTION. EXPECT PRECIP
TO INCREASE AS IT MOVES OVER WESTERN UPR MICHIGAN LATE EVENING AND
OVER REST OF CWA THROUGH THE OVERNIGHT HOURS.
PTYPE WILL BE CONCERN AS RAP/HRRR/NAM SHOW PORTION OF WARM NOSE
ALOFT MAKES IT INTO SW UPR MICHIGAN. MAY BE WARM ENOUGH ALOFT 850-
800MB AOA +3C TO BRIEFLY TURN PRECIP TO FZRA OVER FAR WEST.
ELSEWHERE OVER WEST HALF...SLEET WILL BE POSSIBLE AS WARM LAYER
TEMPS RISE TO +1-2C. HEAVIEST QPF IS PLANNED FOR KEWEENAW. BLEND OF
SHORT TERM HIGH RES GUIDANCE POINTS TO 0.3+ INCHES OVER KEWEENAW
WITH LESSER AMOUNTS OVER REST OF CWA...TAPERING TO LESS THAN 0.10
INCH OVER FAR SOUTH. WITH QPF HIGHEST OVER KEWEENAW AS THAT AREA IS
ALONG TRACK OF SHORTWAVE WENT WITH WINTER WEATHER ADVY FOR SNOW
AMOUNTS MAINLY 2-4 INCHES. IF HRRR OUTPUT IS CORRECT...ISOLD AMOUNTS
AROUND 5 INCHES WOULD NOT BE OUT OF QUESTION MOHAWK TO COPPER
HARBOR. OVER REST OF UPR MICHIGAN...SNOW AMOUNTS WILL BE IN THE 1-3
INCH RANGE. SPS WAS ISSUED TO COVERED SLIPPERY ROADS LATER THIS
EVENING AND OVERNIGHT.
ON SATURDAY...WARM FRONT BLOWS THROUGH IN THE MORNING. MID-LEVEL
MOISTURE IS SCOURED OUT AS THE SHORTWAVE EXITS. ANY PRECIP EARLY
ON WILL BE IN THE FORM OF FZDZ. UPSLOPE WEST WINDS MAY KEEP LOW
CLOUDS AND SOME DZ OVER KEWEENAW INTO THE MIDDAY HOURS...BUT
ELSEWHERE LOW CLOUDS SHOULD GRADUALLY DECREASE. TEMPS ALOFT...JUST
ALOFT AT 925-900MB ARE PRETTY WARM ON THE POSITIVE SIDE OF 0C. MIXING
TO 925MB SUPPORTS MAX TEMPS INTO LOW 40S FOR DOWNSLOPE AREAS. IF WE
CAN MIX TO 900MB...AROUND 3KFT...TEMPS MAY JUMP EVEN HIGHER. WILL ALL
DEPEND ON EXTENT OF SUNSHINE/MIXING. COULD BE BREEZY ON KEWEENAW WITH
WSW WINDS UP TO 20 MPH AND SOME HIGHER GUSTS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 417 PM EST FRI JAN 29 2016
BEGINNING SAT NIGHT...A SHORTWAVE MOVING IN FROM THE NORTHERN PLAINS
WILL PUSH A SFC TROUGH INTO THE AREA. FORCING ASSOC WITH THE
SHORTWAVE COULD SUPPORT SOME LIGHT SNOW ACROSS THE CWA LATE EVENING
INTO OVERNIGHT...AND POSSIBLY A MIX OF SNOW...RAIN OR FREEZING RAIN
OVER SOUTH CENTRAL COUNTIES.
SUN/SUN NIGHT...THE GFS AND NAM ARE SHOWING MORE INTERACTION BETWEEN
A COUPLE OF SHORTWAVES TRACKING ACROSS THE CONUS...RESULTING IN A
DEEPER WAVE TAKING ON A NEGATIVE TILT AS IT SHIFTS ACROSS THE WRN
GREAT LAKES REGION. TO VARYING DEGREES...THE GFS HAS GENERALLY
INDICATED SUCH A SCENARIO FOR SEVERAL RUNS...AND NOW THE NAM HAS
JOINED SUIT THE LAST FEW RUNS. THE GFS IS A BIT QUICKER THAN THE NAM
BRINGING MODERATE TO HEAVY SNOW INTO THE AREA ALREADY ON SUN WHILE
THE NAM INDICATES A POTENTIAL FOR MODERATE TO HEAVY SNOW MAINLY SUN
NIGHT. BOTH MODELS WOULD SUPPORT A HEADLINE EVENT FOR MODERATE TO
HEAVY SNOWFALL AFFECTING MUCH OF THE CWA DURING THE PERIOD.
THE 12Z CANADIAN HAS NOW ALSO TRENDED DEEPER AND FARTHER NORTH WITH
SHORTWAVE AND ASSOC SFC LOW PER NAM AND GFS BUT THE 12Z ECMWF
REMAINS WEAKER AND FARTHER SOUTH ONLY ADDING TO FCST UNCERTAINTY. WL
LIKELY NEED TO BUMP POPS UP A BIT TO REFLECT MODEL CONSENSUS TRENDS
OF STRONGER SYSTEM TRACKING FARTHER NORTH...BUT THIS SYSTEM WILL
DEFINITELY BE ONE TO WATCH OVER THE NEXT FEW MODEL RUNS. IF MODELS
BEGIN TO CONVERGE ON DEEPER AND FARTHER NORTH SOLUTION...WILL LIKELY
NEED WSW HEADLINES FOR A GOOD PORTION OF THE FCST AREA.
MON/MON NIGHT...AFTER ANY LINGERING PCPN ENDS FOLLOWING THE PASSAGE
OF THE SHORTWAVE TO THE E...NW FLOW LOWERING 850MB TEMPS DOWN TO -12
TO -16C FOR AT LEAST A TIME WILL GENERATE SOME LIGHT LES UNDER A LOW
INVERSION.
TUE-WED...GFS/ECMWF/CANADIAN MODELS STILL SHOWING MEANINGFUL
DIFFERENCES REGARDING TRACK OF A POTENTIAL SIGNIFICANT WINTER STORM
TO AFFECT THE GREAT LAKES REGION LATER TUE/WED NEXT WEEK. A NUMBER
OF GFS ENSEMBLES AND CANADIAN ENSEMBLES INCLUDING THE 12Z
OPERATIONAL GFS ARE SUPPORTIVE OF A STRONGER AND FARTHER NORTH SFC
LOW TRACK THROUGH CENTRAL TO NORTHERN LOWER MI WHICH WOULD RESULT IN
MODERATE TO POSSIBLY HEAVY SNOW FOR PROBABLY AT LEAST THE CENTRAL
AND ERN COUNTIES OF UPPER MI. ON THE OTHER HAND...THE 00/12Z
OPERATIONAL ECMWF/CANADIAN/UKMET ARE TRENDING FARTHER SOUTH AND
WEAKER WITH STORM SYSTEM...TRACKING IT THROUGH FAR SRN LOWER MI AND
ACROSS FAR SOUTHERN LAKE HURON WHICH WOULD KEEP MUCH OF THE SYSTEM
SNOW FARTHER SOUTH OF UPPER MI. THE MODEL UNCERTAINTY DEFINITELY
ARGUES FOR TAKING A CONSERVATIVE APPROACH WHEN DETERMINING THE
POSSIBLE IMPACT OF THIS WINTER STORM FOR UPPER MI. IF THE OPERATIONAL
GFS AND THE MAJORITY OF THE GFS ENSEMBLE RUNS PAN OUT MUCH OF THE
CENTRAL AND EASTERN CWA WILL LIKELY SEE AT LEAST ADVISORY TO POSSIBLE
WARNING LEVEL SNOW AMOUNTS. FAIRLY FAST MOVEMENT OF STORM SYSTEM WILL
WORK TO KEEP SYSTEM FROM PRODUCING WIDESPREAD VERY HEAVY SNOW TOTALS.
IN ADDITION...UPSLOPING/POSSIBLE LAKE ENHANCEMENT (850MB TEMPS FALL
FROM -10 TO -15C DURING THE ENHANCEMENT PHASE OFF THE LAKE) COULD ADD
TO SNOW TOTALS OVER NCNTRL UPPER MI. THIS WILL LIKELY BE CASE EVEN IF
THE WEAKER AND FARTHER SOUTH MODEL SOLUTION OF NON NCEP MODELS PAN
OUT.
THU-FRI...MODELS TREND TOWARD GENERALLY A DRIER AND COOLER PERIOD
FOR LATE NEXT WEEK WITH SOME LINGERING LAKE EFFECT IN WESTERLY WIND
SNOW BELTS OF LAKE SUPERIOR. MODELS HINT AT A WEAK SHORTWAVE MOVING
THROUGH THE AREA WHICH MAY PRODUCE A PERIOD OF LIGHT SNOW/FLURRIES
BUT AT THIS TIME IT DOES NOT LOOK LIKE ANYTHING MORE THAN A DUSTING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 716 PM EST FRI JAN 29 2016
AS SFC LOW MOVES TO NW ONTARIO LATE TONIGHT A SWATH OF WINTRY
PRECIPITATION IS EXPECTED JUST AHEAD OF THE WARM
FRONT...IN THE FORM OF SNOW AND SLEET AT IWD AND SAW AND MAINLY
SNOW AT CMX. IFR CONDITIONS AT CMX DUE TO VSBY EXPECTED. LATE
TONIGHT INTO EARLY SAT AS STEADY SNOW TAPERS COULD BE FZDZ. THIS IS
ALSO WHEN CIGS WILL HAVE BEST CHANCE TO FALL BLO 010. ONCE THE WARM
FRONT BLOWS THROUGH...EXPECT SKIES TO CLEAR OUT AND GUSTY SW-W WINDS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 PM EST FRI JAN 29 2016
STRONG LOW TRACKING OVER NORTHERN ONTARIO LATE TONIGHT INTO SATURDAY
MORNING WILL RESULT IN SOUTH WINDS 20-30 KTS...WITH GALES TO 35 KTS
OVER EAST HALF. GALE WARNING WAS ISSUED. WINDS DIMINISH SAT NIGHT
INTO SUN AS RIDGING MOVES OVERHEAD. A COUPLE OF LOW PRESSURE SYSTEMS
TRACKING ACROSS THE CENTRAL GREAT LAKES MAY BRING NORTH TO NORTHEAST
GALES SUN NIGHT INTO MON AND AGAIN TUE NIGHT INTO WED. AT THIS TIME
BEST CHANCE FOR WIDESPREAD GALES WOULD BE TUE NIGHT INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 9 AM EST SATURDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST SATURDAY FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
101 AM EST THU JAN 28 2016
.UPDATE...
QUICK LATE NIGHT UPDATE TO ADD POTENTIAL FOR FREEZING DRIZZLE TO
THE FORECAST FOR THE REMAINDER OF TONIGHT THROUGH MID-MORNING.
SATELLITE TRENDS OVER THE WESTERN PORTION OF THE STATE SHOW CLOUD
TOPS HAVE WARMED TO BETWEEN -10 AND -13C. THESE SHOULD CONTINUE TO
WARM AS MID-LEVEL DRY SLOW EXTENDING BACK THROUGH WISCONSIN WORKS
ACROSS THE AREA EARLY THIS MORNING...STRIPPING ICE NUCLEI OUT OF
THE DENDRITIC GROWTH ZONE. MEANWHILE...UPSTREAM OBSERVATIONS OF
CEILINGS HEIGHTS SHOW AN INCREASE IN LOW-LEVEL MOISTURE
OCCURRING. THIS SHOULD SET THE STAGE FOR SOME FREEZING DRIZZLE
FROM PTK NORTH...PER GUIDANCE FROM 00Z FORECAST SOUNDINGS. WILL
MONITOR UPSTREAM RADAR TRENDS (WHICH DO SHOW A DRIZZLE SIGNATURE)
AND REPORTS FOR COVERAGE. SOME SLICK SPOTS MAY DEVELOP ON AREA
ROADWAYS WITH THE FREEZING DRIZZLE...ESPECIALLY WHERE ROADS ARE
DRY AND UNCOVERED WITH THE DUSTING OF SNOW MAY LOCATIONS NORTH OF
FNT RECEIVED EARLIER.
&&
.AVIATION...ISSUED 1202 AM EST THU JAN 28 2016
STRONG LOW PRESSURE EXITING LAKE SUPERIOR WILL SWEEP MID LEVEL
MOISTURE OUT OF SE MICHIGAN DURING THE EARLY MORNING AND MAINTAIN A
GUSTY WIND FIELD THROUGH THE NIGHT. A WARM FRONT MOVING IN FROM THE
MIDWEST WILL THEN BRING A SWAP IN THE VERTICAL MOISTURE DISTRIBUTION
AS THE MID LEVEL DRY SLOT WORKS OVER THE REGION WHILE DRY AIR IN THE
LOW LEVELS IS REPLACED BY A FIELD OF STRATUS. THIS HAS SET THE STAGE
FOR CONSIDERABLE COVERAGE OF FREEZING DRIZZLE OVER NORTHERN LOWER
MICHIGAN BUT WITH THE POTENTIAL SOUTHWARD EXTENT STILL TO BE
DETERMINED. PLAN TO MONITOR OBSERVATIONS FOR SIGNS OF IT REACHING AS
FAR SOUTH AS MBS. TERMINALS TO THE SOUTH FROM PTK THROUGH THE DTW
CORRIDOR WILL JUST EXPERIENCE A RETURN TO MVFR CEILING FOR NOW WITH
NORTHWEST TO SOUTHEAST TIMING THROUGH THE NIGHT THEN LASTING THROUGH
MUCH OF THURSDAY UNTIL THE COLD FRONT PASSES DURING THE AFTERNOON
INTO EARLY THURSDAY EVENING. THE COLD FRONT WILL LIKELY BRING SOME
SNOW SHOWERS ALONG WITH IT AND FOR A FEW HOURS EITHER SIDE.
FOR DTW... A FLURRY OR BRIEF SNOW SHOWER WILL EXIT QUICKLY EASTWARD
SHORTLY AFTER MIDNIGHT. VFR WILL BE REPLACED BY MVFR CEILING LATER
IN THE NIGHT WHILE GUSTY WIND PERSISTS THROUGHOUT. SNOW SHOWERS WILL
BECOME MORE ACTIVE AS THE COLD FRONT APPROACHES DURING THE MID
AFTERNOON AND MOVES THROUGH DTW EARLY THURSDAY EVENING.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CIGS BLO 5KFT AFTER 10Z LASTING THROUGH THE DAY.
* HIGH FOR PTYPE AS SNOW.
&&
.PREV DISCUSSION...ISSUED 928 PM EST WED JAN 27 2016
UPDATE...
SATELLITE PRESENTATION INDICATES A POWERFUL SHORT WAVE MOVING
THROUGH THE NORTHERN GREAT LAKES DURING THE EVENING. THIS SYSTEM
IS RESPONSIBLE FOR DRAWING A PLUME OF HIGHER THETA-E AIR THROUGH
THE MID LEVELS OVER LOWER MICHIGAN. ISENTROPIC ASCENT IS SHALLOW
BUT ADEQUATE FOR A BAND OF MID LEVEL MOISTURE ON RADAR THAT WILL
BATTLE DRY AIR IN THE LOW LEVELS THROUGH THE NIGHT. THE 00Z APX
SOUNDING IS A GOOD DEPICTION OF THE PARTIAL SATURATION EXPECTED TO
OCCUR FROM THE FORMIDABLE STARTING POINT SHOWN IN THE DTX
SOUNDING. MOST RECENT RUNS OF THE RAP AND NAM INDICATE DRY AIR
WILL HOLD ON AROUND THE 850 MB LAYER OVER MUCH OF SE MICHIGAN WITH
BETTER CHANCES FOR POCKETS OF SATURATION FROM FLINT THROUGH THE
TRI CITIES AND NORTHERN THUMB. EXPECT GENEROUS COVERAGE OF VIRGA
ON RADAR BUT JUST A CHANCE OF FLURRIES SOUTH THROUGH METRO DETROIT
DURING THE NIGHT. THE LOW PRESSURE SYSTEM WILL THEN SWEEP THE MID
LEVEL MOISTURE AXIS TO OUR EAST BY SUNRISE LEAVING LOW CLOUDS TO
SPREAD BACK OVER THE REGION DURING THURSDAY MORNING.
&&
.PREV DISCUSSION...ISSUED 328 PM EST WED JAN 27 2016
DISCUSSION...
CLIPPER SYSTEM JUST NORTH OF MINNESOTA WILL TRACK TO EASTERN LAKE
SUPERIOR BY 12Z THURSDAY THEN TO EAST OF LAKE HURON BY 00Z FRI.
TIGHTENING SURFACE GRADIENT WILL BRING AN INCREASE IN SOUTHWEST FLOW
TONIGHT INTO THURSDAY AFTERNOON ALONG WITH MILDER TEMPS. MOISTURE
WILL BE LIMITED AS SYSTEM ACROSS THE SOUTHEAST U.S. BLOCKS ANY DECENT
MOISTURE TRANSPORT NORTH. THE HEAVIEST SNOW ACTIVITY TONIGHT WILL BE
CONFINED CLOSER TO THE CLIPPER SYSTEM MAINLY NORTH OF THE FORECAST
AREA BUT WILL SEE SOME LIGHT ACTIVITY ACROSS THE SAGINAW VALLEY AND
THUMB. WILL CARRY A CHANCE FOR SNOW SHOWERS THURSDAY ACROSS THE
ENTIRE AREA AS COLD FRONT ASSOCIATED WITH CLIPPER SWEEPS THROUGH
DURING THE AFTERNOON.
HIGH PRESSURE FRIDAY WILL BRING SLIGHTLY COLDER TEMPS ALONG WITH
SOME PARTIAL CLEARING. ANOTHER CLIPPER WILL QUICKLY SWEEP ACROSS
THE LAKE SUPERIOR LIFTING A WARM FRONT THROUGH THE AREA SATURDAY
WITH A CHANCE FOR RAIN/SNOW SHOWERS AS TEMPS WILL RISE INTO THE 40S
MOST LOCALS. TEMPERATURES WILL REMAIN MILD INTO SUNDAY ALONG WITH
CHANCE FOR RAIN SHOWERS AHEAD OF A SLOW MOVING COLD FRONT WHICH
WILL BRING COLDER AIR FOR MON/TUES. THE NEXT MAJOR SYSTEM WILL BE A
LARGE AND STRONG DEVELOPING LOW PRESSURE SYSTEM OVER THE MID WEST
THAT WILL LIFT INTO THE WESTERN LAKES. THIS WILL BRING A CHANCE FOR
MIX PRECIPITATION LATE IN THE DAY TUESDAY THAT MAY TRANSITION
TO ALL RAIN OR RAIN MIX WITH SNOW WEDNESDAY.
MARINE...
A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE NORTHERN GREAT LAKES
TONIGHT AND THURSDAY. A TIGHTENING PRESSURE GRADIENT AHEAD OF THE
SYSTEM WILL CAUSE WINDS TO INCREASE WITH SUSTAINED FLOW APPROACHING
30 KNOTS AND GUSTS REACHING GALE FORCE STARTING TONIGHT. A GALE
WARNING IS IN EFFECT FOR CENTRAL LAKE HURON AND OUTER SAGINAW. WINDS
WILL RELAX A BIT THURSDAY AFTERNOON AS THE ASSOCIATED COLD FRONT
DROPS THROUGH THE REGION BUT WILL INCREASE TO NEAR GALE FORCE ONCE
AGAIN THURSDAY NIGHT AS COLD AIR SURGES INTO THE REGION. HIGH
PRESSURE AND A DAY OF LIGHTER WINDS WILL SETTLE IN FOR FRIDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LHZ362-363-421.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......HLO
AVIATION.....BT
DISCUSSION...DRC
MARINE.......DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1202 AM EST THU JAN 28 2016
.AVIATION...
STRONG LOW PRESSURE EXITING LAKE SUPERIOR WILL SWEEP MID LEVEL
MOISTURE OUT OF SE MICHIGAN DURING THE EARLY MORNING AND MAINTAIN A
GUSTY WIND FIELD THROUGH THE NIGHT. A WARM FRONT MOVING IN FROM THE
MIDWEST WILL THEN BRING A SWAP IN THE VERTICAL MOISTURE DISTRIBUTION
AS THE MID LEVEL DRY SLOT WORKS OVER THE REGION WHILE DRY AIR IN THE
LOW LEVELS IS REPLACED BY A FIELD OF STRATUS. THIS HAS SET THE STAGE
FOR CONSIDERABLE COVERAGE OF FREEZING DRIZZLE OVER NORTHERN LOWER
MICHIGAN BUT WITH THE POTENTIAL SOUTHWARD EXTENT STILL TO BE
DETERMINED. PLAN TO MONITOR OBSERVATIONS FOR SIGNS OF IT REACHING AS
FAR SOUTH AS MBS. TERMINALS TO THE SOUTH FROM PTK THROUGH THE DTW
CORRIDOR WILL JUST EXPERIENCE A RETURN TO MVFR CEILING FOR NOW WITH
NORTHWEST TO SOUTHEAST TIMING THROUGH THE NIGHT THEN LASTING THROUGH
MUCH OF THURSDAY UNTIL THE COLD FRONT PASSES DURING THE AFTERNOON
INTO EARLY THURSDAY EVENING. THE COLD FRONT WILL LIKELY BRING SOME
SNOW SHOWERS ALONG WITH IT AND FOR A FEW HOURS EITHER SIDE.
FOR DTW... A FLURRY OR BRIEF SNOW SHOWER WILL EXIT QUICKLY EASTWARD
SHORTLY AFTER MIDNIGHT. VFR WILL BE REPLACED BY MVFR CEILING LATER
IN THE NIGHT WHILE GUSTY WIND PERSISTS THROUGHOUT. SNOW SHOWERS WILL
BECOME MORE ACTIVE AS THE COLD FRONT APPROACHES DURING THE MID
AFTERNOON AND MOVES THROUGH DTW EARLY THURSDAY EVENING.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CIGS BLO 5KFT AFTER 10Z LASTING THROUGH THE DAY.
* HIGH FOR PTYPE AS SNOW.
&&
.PREV DISCUSSION...ISSUED 928 PM EST WED JAN 27 2016
UPDATE...
SATELLITE PRESENTATION INDICATES A POWERFUL SHORT WAVE MOVING
THROUGH THE NORTHERN GREAT LAKES DURING THE EVENING. THIS SYSTEM
IS RESPONSIBLE FOR DRAWING A PLUME OF HIGHER THETA-E AIR THROUGH
THE MID LEVELS OVER LOWER MICHIGAN. ISENTROPIC ASCENT IS SHALLOW
BUT ADEQUATE FOR A BAND OF MID LEVEL MOISTURE ON RADAR THAT WILL
BATTLE DRY AIR IN THE LOW LEVELS THROUGH THE NIGHT. THE 00Z APX
SOUNDING IS A GOOD DEPICTION OF THE PARTIAL SATURATION EXPECTED TO
OCCUR FROM THE FORMIDABLE STARTING POINT SHOWN IN THE DTX
SOUNDING. MOST RECENT RUNS OF THE RAP AND NAM INDICATE DRY AIR
WILL HOLD ON AROUND THE 850 MB LAYER OVER MUCH OF SE MICHIGAN WITH
BETTER CHANCES FOR POCKETS OF SATURATION FROM FLINT THROUGH THE
TRI CITIES AND NORTHERN THUMB. EXPECT GENEROUS COVERAGE OF VIRGA
ON RADAR BUT JUST A CHANCE OF FLURRIES SOUTH THROUGH METRO DETROIT
DURING THE NIGHT. THE LOW PRESSURE SYSTEM WILL THEN SWEEP THE MID
LEVEL MOISTURE AXIS TO OUR EAST BY SUNRISE LEAVING LOW CLOUDS TO
SPREAD BACK OVER THE REGION DURING THURSDAY MORNING.
PREV DISCUSSION...ISSUED 328 PM EST WED JAN 27 2016
DISCUSSION...
CLIPPER SYSTEM JUST NORTH OF MINNESOTA WILL TRACK TO EASTERN LAKE
SUPERIOR BY 12Z THURSDAY THEN TO EAST OF LAKE HURON BY 00Z FRI.
TIGHTENING SURFACE GRADIENT WILL BRING AN INCREASE IN SOUTHWEST FLOW
TONIGHT INTO THURSDAY AFTERNOON ALONG WITH MILDER TEMPS. MOISTURE
WILL BE LIMITED AS SYSTEM ACROSS THE SOUTHEAST U.S. BLOCKS ANY DECENT
MOISTURE TRANSPORT NORTH. THE HEAVIEST SNOW ACTIVITY TONIGHT WILL BE
CONFINED CLOSER TO THE CLIPPER SYSTEM MAINLY NORTH OF THE FORECAST
AREA BUT WILL SEE SOME LIGHT ACTIVITY ACROSS THE SAGINAW VALLEY AND
THUMB. WILL CARRY A CHANCE FOR SNOW SHOWERS THURSDAY ACROSS THE
ENTIRE AREA AS COLD FRONT ASSOCIATED WITH CLIPPER SWEEPS THROUGH
DURING THE AFTERNOON.
HIGH PRESSURE FRIDAY WILL BRING SLIGHTLY COLDER TEMPS ALONG WITH
SOME PARTIAL CLEARING. ANOTHER CLIPPER WILL QUICKLY SWEEP ACROSS
THE LAKE SUPERIOR LIFTING A WARM FRONT THROUGH THE AREA SATURDAY
WITH A CHANCE FOR RAIN/SNOW SHOWERS AS TEMPS WILL RISE INTO THE 40S
MOST LOCALS. TEMPERATURES WILL REMAIN MILD INTO SUNDAY ALONG WITH
CHANCE FOR RAIN SHOWERS AHEAD OF A SLOW MOVING COLD FRONT WHICH
WILL BRING COLDER AIR FOR MON/TUES. THE NEXT MAJOR SYSTEM WILL BE A
LARGE AND STRONG DEVELOPING LOW PRESSURE SYSTEM OVER THE MID WEST
THAT WILL LIFT INTO THE WESTERN LAKES. THIS WILL BRING A CHANCE FOR
MIX PRECIPITATION LATE IN THE DAY TUESDAY THAT MAY TRANSITION
TO ALL RAIN OR RAIN MIX WITH SNOW WEDNESDAY.
MARINE...
A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE NORTHERN GREAT LAKES
TONIGHT AND THURSDAY. A TIGHTENING PRESSURE GRADIENT AHEAD OF THE
SYSTEM WILL CAUSE WINDS TO INCREASE WITH SUSTAINED FLOW APPROACHING
30 KNOTS AND GUSTS REACHING GALE FORCE STARTING TONIGHT. A GALE
WARNING IS IN EFFECT FOR CENTRAL LAKE HURON AND OUTER SAGINAW. WINDS
WILL RELAX A BIT THURSDAY AFTERNOON AS THE ASSOCIATED COLD FRONT
DROPS THROUGH THE REGION BUT WILL INCREASE TO NEAR GALE FORCE ONCE
AGAIN THURSDAY NIGHT AS COLD AIR SURGES INTO THE REGION. HIGH
PRESSURE AND A DAY OF LIGHTER WINDS WILL SETTLE IN FOR FRIDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING UNTIL 7 AM EST THURSDAY FOR LHZ362-363-421.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
UPDATE.......BT
DISCUSSION...DRC
MARINE.......DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1157 PM EST WED JAN 27 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EST WED JAN 27 2016
A CLIPPER SYSTEM MOVING THROUGH THE NORTHERN GREAT LAKES REGION
TONIGHT WILL BRING A QUICK BURST OF SNOW TO SOUTHWEST LOWER
MICHIGAN. AREAS DOWNWIND OF LAKE MICHIGAN FROM ABOUT SAUGATUCK
NORTHWARD WILL SEE A COUPLE ROUNDS OF SNOW TONIGHT THAT MAY
ACCUMULATE TO 1 TO 3 INCHES. A FEW SPOTS ACROSS WEST CENTRAL LOWER
MICHIGAN COULD SEE 4 INCHES. OVERNIGHT THERE IS THE POSSIBILITY OF
SOME FREEZING DRIZZLE AS WELL. COLDER AIR WILL FILTER INTO THE AREA
ON THURSDAY AND BRING LAKE EFFECT SNOW INTO THE PICTURE AGAIN FOR
THURSDAY AFTERNOON AND THURSDAY NIGHT. ACCUMULATIONS DURING THIS
TIME FRAME ARE EXPECTED TO BE LIGHT. ANOTHER CLIPPER SYSTEM WILL
BRING ANOTHER ROUND OF SOME LIGHT SNOW FRIDAY NIGHT. TEMPERATURES
THE REMAINDER OF THE WORK WEEK WILL BE NEAR NORMAL FOR THIS TIME OF
YEAR.
&&
.UPDATE...
ISSUED AT 858 PM EST WED JAN 27 2016
MADE SOME CHANGES TO THE FORECAST. WE CANCELLED THE WINTER WX
ADVISORY. BASED ON RADAR TRENDS OVER THE CWA AND UPSTREAM IT
CERTAINLY APPEARS THAT WE WON/T SEE THE SNOW WE ORIGINALLY THOUGHT
WOULD OCCUR. MOISTURE IS TOO SHALLOW AND THE CONTRIBUTION FROM THE
LAKE IS TOO WEAK. EVEN THOUGH THE NAM AND GFS CONTINUE TO POINT
TOWARD PCPN OVERNIGHT...THE RAP AND HRRR ARE BASICALLY DRY WHICH
LINES UP WITH THE RADAR. A FEW FLURRIES OR BRIEF SNOW SHOWER ARE
POSSIBLE BUT ACCUMS ARE NOT EXPECTED. WE ALSO DECREASED POPS FOR
THURSDAY MORNING. STILL COULD SEE SOME SNOW SHOWERS THURSDAY
AFTERNOON AS COLDER AIR MOVES ACROSS THE LAKE.
UPDATE ISSUED AT 627 PM EST WED JAN 27 2016
BASED ON THE LATEST MODEL GUIDANCE IT SEEMS WE WILL BE SEEING A
BAND OF SNOW SHOWERS CROSS THE ADVISORY AREA DURING THE MID
EVENING HOURS. THEN THE DEEP MOISTURE DROPS OUT SO MORE THAN
LIKELY WE WILL BE SEEING MOSTLY FREEZING DRIZZLE AND SNOW GRAINS
OVERNIGHT. THE OTHER ISSUE IS SURFACE TEMPERATURES RISE ABOVE
FREEZING ALONG THE LAKE SHORE BY 10 PM...THAT REACHES US-131 BY 3
TO 4 AM. SO THEN WE WOULD JUST HAVE MIXED RAIN AND SNOW SHOWERS. I
TEMPERATURES RISE ABOVE FREEZING ACROSS THE CWA BY 10 AM THURSDAY
BUT THE AIR IS COLD ENOUGH FOR SNOW TO REACH THE GROUND.... SO I
HAVE MIXED RAIN/SNOW MID MORNING GOING TO LIGHT SNOW SHOWERS IN
THE AFTERNOON. THE SNOW WILL BE TO WET TO BLOW AROUND...SO EVEN
WITH THE WIND I DO NOT FEEL WE NEED BLOWING SNOW IN OUR FORECAST
TONIGHT. BOTTOM LINE IS I UPDATED THE FORECAST TO ACCOMADATE ALL
OF THESE IDEAS. I WILL LEAVE THE WINTER WEATHER ADVISORY AS IS AS
IT DOES MENTION FREEZE DRIZZLE ALREADY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM EST WED JAN 27 2016
FOCUS IS ON THE WINTER WEATHER ADVISORY THAT REMAINS IN EFFECT FOR
FAVORED SOUTHWEST FLOW AREAS TONIGHT. WILL BE MAKING NO CHANGES TO
THE GOING HEADLINE. STILL LOOKS LIKE THERE COULD BE SOME IMPACT FROM
A COUPLE ROUNDS OF QUICK HITTING SNOW TONIGHT. THE HRRR FOR MULTIPLE
RUNS NOW TODAY IS SHOWING SEVERAL BURSTS OF SNOW ACROSS THE ADVISORY
AREA TONIGHT. THERE IS SOME LAKE ENHANCEMENT THAT IS POSSIBLE WITH
DELTA T/S OF 8 TO 11 DEGREE C. STRONG LIFT IS NOTED IN THE BUFKIT
TIME SECTIONS ESPECIALLY THIS EVENING. THE LIFT IS ASSOCIATED WITH A
ONE/TWO PUNCH FROM A COUPLE OF SHORTWAVES THAT WILL TRAVERSE THE
AREA TONIGHT. THE FIRST COMES THROUGH IN THE 00-06Z TIME FRAME WITH
ANOTHER AFTER 06Z. MOISTURE WILL BE LIMITED AT TIMES BUT THE BURST
OF SNOW SHOULD PUT DOWN 1 TO POSSIBLE 4 INCHES OF SNOW. THE HIGHEST
TOTALS WILL LIKELY BE ON THE HIGH GROUND ACROSS EASTERN LAKE AND
OSCEOLA COUNTIES.
IMPACTS MAY BE MODULATED SOME HOWEVER BY THE FACT THAT AIR TEMPS ARE
GOING TO BE NEAR FREEZING. ALSO...THE FACT THAT THE BLOWING SNOW
WILL BE HELD IN CHECK BY THE WET NATURE OF THE SNOW. OVERNIGHT SOME
FREEZING DRIZZLE IS POSSIBLE GIVEN THAT THE DGZ BECOMES UNSATURATED
WITH CONTINUED LIFT IN THE CLOUD LAYER. AGAIN...THE FREEZING DRIZZLE
MAY BE MITIGATED BY THE SLOWING RISING TEMPS OVERNIGHT.
SOME LAKE EFFECT SNOW IS EXPECTED THURSDAY AFTERNOON INTO FRIDAY
MORNING AS DELTA T/S PEAK IN THE MID TO UPPER TEENS. MOISTURE DEPTH
IS DECREASING WITH TIME AND THINKING WE ARE NOT LOOKING AT ANYTHING
TOO HEAVY...ON THE ORDER OF AN INCH OR TWO.
ANOTHER CLIPPER IN THE SERIES ROTATES THROUGH FRIDAY NIGHT AND WE
WILL BE IN THE SOUTHERN FLANK ONCE AGAIN. 850MB TEMPS ARE TRENDING
TOWARD THE NEED TO INTRODUCE A MIX OF PRECIPITATION. AT THIS POINT
KEPT THINGS ALL LIGHT SNOW WITH CHANCE POPS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM EST WED JAN 27 2016
AN ACTIVE WX PATTERN WILL DEVELOP THROUGH THE LONG RANGE FCST
PERIOD. ONE LOW PRESSURE SYSTEM WILL TRACK EAST ACROSS THE NORTHERN
GREAT LAKES REGION SATURDAY AND BRING A CHANCE OF MIXED LIGHT RAIN
AND LIGHT SNOW SHOWERS EARLY IN THE DAY SATURDAY.
ANOTHER LOW PRESSURE SYSTEM WILL QUICKLY MOVE IN ON SUNDAY AND BRING
RAIN SHOWERS. TEMPERATURES WILL AVERAGE ABOVE TO MUCH ABOVE NORMAL
THIS WEEKEND WHEN HIGH TEMPERATURES WILL REACH INTO THE 40S.
A MORE SIGNIFICANT LOW PRESSURE SYSTEM WILL DEVELOP OVER THE
SOUTHERN PLAINS MONDAY. THIS SYSTEM WILL TAP LOTS OF GULF MOISTURE
AS IT ADVANCES NE TOWARD OUR AREA LATE MONDAY NIGHT AND TUESDAY.
THIS SYSTEM HAS POTENTIAL TO BRING SIGNIFICANT WINTRY PRECIPITATION
LATE MONDAY NIGHT THROUGH TUESDAY AND TUESDAY NIGHT. THERE IS ALSO
POTENTIAL FOR SOME ICE GIVEN THE EVOLUTION OF THE SYNOPTIC PATTERN
WHICH WILL ALSO FEATURE A HIGH PRESSURE RIDGE TO OUR NORTH BY
TUESDAY.
THERE IS STILL CONSIDERABLE UNCERTAINTY REGARDING THE STRENGTH AND
EXACT TRACK OF THIS SYSTEM. HOWEVER THE GENERAL NOTION IS
UNDOUBTEDLY THERE THAT IT COULD POTENTIALLY BRING A SIGNIFICANT
AMOUNT OF WINTRY PCPN LATE MONDAY NIGHT THROUGH TUESDAY NIGHT WITH
POTENTIAL TO CAUSE SIGNIFICANT IMPACTS. WE WILL CONTINUE TO MONITOR
THE EVOLUTION OF THAT SYSTEM CLOSELY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1157 PM EST WED JAN 27 2016
OUR SNOW BAND DID NOT WORK OUT SO GREAT... BUT I STILL BELIEVE LOW
LEVEL MOISTURE FROM WISCONIN WILL SPREAD ACROSS THE CWA OVER THE
NEXT FEW HOURS AND RESULT IN DRIZZLE WERE TEMPERATURES ARE ABOVE
FREEZING... LIKE MKG... BUT FREEZING DRIZZLE INLAND OF THAT AT
GRR...AZO...BTL...LAN AND JXN. ALL AREAS WILL WARM ABOVE FREEZING
BY MID MORNING SO THAT SHOULD END FREEZING DRIZZLE BY MID MORNING.
DEEPER MOISTURE WITH THE COLD FRONT SHOULD RESULT IN SNOW SHOWERS
ACROSS THE AREA IN THE AFTERNOON. WINDS TURNING MORE TO THE NORTH
BEHIND THE COLD FRONT SHOULD END THE SNOW SHOWERS MOST AREA BY
EARLY EVENING.
&&
.MARINE...
ISSUED AT 330 PM EST WED JAN 27 2016
ISSUED A GALE WARNING EARLY TODAY AS IT IS EXPECTED THAT WINDS WILL
SURGE TO GALE FORCE THIS EVENING. THERE IS ABOUT A 6 HOUR WINDOW
TONIGHT WHERE THE GRADIENT TIGHTENS TO THE POINT THAT WE ARE
EXPECTING 35-40 KNOT GALES. THE STRONGER GALES WILL BE ALONG THE
HIGHER BLUFFS OF THE NORTHERN HALF OF THE LAKESHORE...NORTH OF GRAND
HAVEN. WAVES SHOULD BUILD TOWARD 10 FEET OVERNIGHT.
THE WINDS WILL QUICKLY COME DOWN BELOW GALE FORCE LATE TONIGHT...BUT
REMAIN UP IN THE 20-25 KNOT RANGE BOTH THURSDAY AND THURSDAY NIGHT.
A SMALL CRAFT ADVISORY WAS ISSUED LAST NIGHT AND THAT REMAINS IN
EFFECT NOW FOR THURSDAY AND THURSDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 205 PM EST WED JAN 27 2016
LITTLE HAS CHANGED IN THE LAST 24 HOURS. FLOODING CONCERNS ARE
MINIMAL WITH MINOR PRECIPITATION AMOUNTS EXPECTED THROUGH THE NEXT
5 DAYS. THE MAIN TOPIC IS MORE THAN LIKELY WHAT COMES TOWARD THE
END OF THE LONG TERM (NEXT WEEK).
A FEW ROUNDS OF PRECIPITATION WILL BE MOVING THROUGH THE GREAT
LAKES REGION BETWEEN NOW AND THIS WEEKEND. EACH ROUND IS EXPECTED
TO BRING MINOR PRECIPITATION AMOUNTS. SNOWFALL IS THE LIKELY MODE
OF PRECIPITATION THROUGH FRIDAY. MILDER WEATHER WILL BE PUSHING
INTO LOWER MICHIGAN THIS WEEKEND...WITH TEMPERATURES PUSHING INTO
THE 40S BY SUNDAY...IF NOT AS EARLY AS SATURDAY. RAIN WILL BE
POSSIBLE AGAIN BY LATE SUNDAY.
THE REAL CONCERN EXTENDS INTO NEXT WEEK WITH WHAT MAY BE A RATHER
POTENT SYSTEM. MANY QUESTIONS STILL EXIST WITH PRECIPITATION TYPE
AND STORM TRACK. THAT SAID...THE STORM LOOKS TO BE EQUIPPED WITH
PLENTY OF MOISTURE. IF THE PRECIPITATION TYPE IS RAIN...WE COULD
BE LOOKING AT RIVER RISES THROUGH THE MIDDLE OF NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 AM THURSDAY TO 7 AM EST FRIDAY FOR
LMZ844>849.
GALE WARNING UNTIL 7 AM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...04
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...LAURENS
AVIATION...WDM
HYDROLOGY...JAM
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1150 PM EST WED JAN 27 2016
.UPDATE...
ISSUED AT 1127 PM EST WED JAN 27 2016
INDEED...SEVERAL REPORTS OF FREEZING DRIZZLE AND SOME COATINGS OF
ICE OUT THERE FOR MOST ALL AREAS OF NRN LOWER AND EVEN SOME
SPOTTIER REPORTS ACROSS EASTERN UPPER. WENT AHEAD AND ISSUED AN
ADVISORY FOR DEVELOPING BLACK ICE/VERY SLIPPERY ROADS...MAINLY ON
UNTREATED ROADS WITH LITTLE TO NO SNOW COVER. A BAND OF DEEPER
MOISTURE IS SLIDING INTO EMMET COUNTY AND EXTENDING UP THROUGH
WESTERN CHIP/MACK. THIS OUT AHEAD OF A WEAK VORT MAX. THIS WILL
RESULT IN SNOW. CONCERN IS FOR THE CHANCE FOR THINGS TO GO BACK TO
FREEZING DRIZZLE AFTER IS PASSES THROUGH. RIGHT NOW...ALL OF NRN
LOWER IN A NEW ADVISORY FOR FREEZING DRIZZLE.
UPDATE ISSUED AT 1049 PM EST WED JAN 27 2016
LATEST WV IMAGERY AND HI RES SOUNDING DATA SHOWS DEEPER MOISTURE
HAS BEEN STRIPPED OUT ALOFT...AND THE TRAPPED LOWER LEVEL MOISTURE
IS ALL UNDER -10C WITH STRONG WINDS HELPING TO DEVELOP AREAS OF
FREEZING DRIZZLE. WILL BE MONITORING FOR A POSSIBLE NEW HEADLINE
FOR ICING.
UPDATE ISSUED AT 943 PM EST WED JAN 27 2016
RATHER SUBSTANTIAL UPDATES THIS EVENING. WAA BAND OF SNOWS THAT
ROLLED THROUGH AMOUNTED TO VERY LITTLE...AND CONDITIONS ARE LESS
THAN MARGINAL FOR THE DEVELOPMENT OF LAKE EFFECT. THERE IS A VORT
MAX SWINGING DOWN INTO FAR NRN LAKE MICHIGAN AND THERE WILL BE A
AN UPTICK IN THE SNOWFALL. THERE WAS SOME CONSIDERATION FOR
KEEPING THE ADVISORIES FOR EASTERN UPPER AND EMMET COUNTY TO TAKE
THIS INTO ACCOUNT. HOWEVER...THE OVERALL COMBINATION OF SNOW AND
WIND ON REDUCED VISIBILITY IS EXPECTED TO BE MUCH LESS. THUS...THE
WINTER WEATHER ADVISORY HAS BEEN CANCELLED. THE CLIPPER`S COLD
FRONT DROPS INTO THE REGION 12-16Z THURSDAY...AND WILL HAVE
MINIMAL EFFECT FOR AREAS AWAY FROM THE LAKES...BUT ACROSS NW LOWER
AND CHIPPEWA COUNTY...A BURST OF SNOW AND REDUCED VISIBILITY IS
LIKELY DUE TO MOISTURE FLUX OFF THE LAKES.
MADE THE APPROPRIATED ADJUSTMENTS TO THE FORECAST...LOWERED
CHANCES FOR SNOW AND LOWERED OVERALL SNOWFALL EXPECTATIONS.
&&
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 337 PM EST WED JAN 27 2016
SURFACE RIDGE AXIS CONTINUES TO EXIT EAST AWAY FROM MICHIGAN THIS
AFTERNOON. UPSTREAM LOW PRESSURE IS NEARING THE ARROWHEAD OF
MINNESOTA...WITH THE TRAILING COLD FRONT EXTENDING SOUTHWARD THRU
THE UPPER MISSISSIPPI VALLEY AND INTO THE CENTRAL PLAINS. LOW LEVEL
SW FLOW/WAA CONTINUES TO STRENGTHEN ACROSS THE WRN GREAT LAKES
REGION BETWEEN THESE TWO SYSTEMS...LIMITING ANY RESIDUAL LAKE EFFECT
PRECIP TO MAINLY FLURRIES ACROSS OUR CWA ATTM.
LATEST BASE REF IMAGES FROM UPSTREAM RADARS SHOW THE LEADING EDGE OF
WIDESPREAD SNOW TAKING SHAPE OVER UPPER MICHIGAN AND WISCONSIN IN
ADVANCE OF THE LOW CENTER AND COLD FRONT. BOTH THE RAP AND THE NAM
SHOW THIS LEADING EDGE REACHING OUR WRN CWA JUST BEFORE 00Z...
QUICKLY SPREADING EASTWARD THRU THE REST OF OUR CWA THEREAFTER. WITH
DELTA T`S OF AROUND 10 DEGREES...SUSPECT LOCATIONS DOWNWIND OF SW
FLOW OFF OF LAKE MICHIGAN (I.E. OUR FAR WRN CWA) MAY VERY WELL SEE
SOME LAKE ENHANCEMENT ONCE INCREASING MID LEVEL MOISTURE BEGINS TO
ACTIVATE SEEDER/FEEDER PROCESSES ALOFT PER LATEST MODEL SOUNDINGS
AND CROSS SECTIONS. WE SHOULD BEGIN TO SEE THIS TAKING SHAPE LATE
THIS AFTERNOON...WITH WIDESPREAD SNOW DEVELOPING EARLY THIS EVENING
ONCE MID LEVELS MOISTEN.
CURRENT WINTER WX ADVISORIES ACROSS ERN UPR AND NW LWR MICHIGAN
REMAIN IN LINE WITH LATEST MODEL TRENDS...AND IN COORDINATION WITH
GRR...WILL KEEP ALL HEADLINES IN TACT. STILL EXPECT A GENERAL 2 TO 4
INCHES OF SNOW FOR THESE AREAS...TAPERING TO LESS THAN AN INCH
ACROSS NE LWR MICHIGAN AWAY FROM ANY LAKE ENHANCEMENT. CERTAINLY THE
GUSTY SW WINDS WILL PRODUCE BLOWING AND DRIFTING SNOW...AND MAKE
OVERALL DRIVING CONDITIONS RATHER HAZARDOUS TONIGHT INTO EARLY
THURSDAY...WHICH DECIDEDLY THROWS THIS EVENT INTO ADVISORY TERRITORY
DESPITE BORDERLINE SNOW AMOUNTS. TEMPS WILL STAY NEARLY STEADY
TONIGHT INTO THE MID TO UPPER 20S THANKS TO WAA AND AMPLE CLOUD
COVER.
&&
.SHORT TERM...(THURSDAY THROUGH SATURDAY)
ISSUED AT 337 PM EST WED JAN 27 2016
FORECAST CHALLENGE: SEVERAL CLIPPER SYSTEMS TO DROP INTO THE UPPER
GREAT LAKES, BRINGING POSSIBLE PRECIPITATION TYPE PROBLEMS, AND LAKE
EFFECT.
(1/28)THURSDAY...THE CLIPPER SYSTEM IS IN EASTERN LAKE SUPERIOR AT
12Z. AS IT MOVES EAST IN THE MORNING, THE SFC PRESSURE GRADIENT
TIGHTENS UP QUITE A BIT BY 18Z, AND WE START GETTING NW WINDS OF 15-
20 KNOTS ACROSS N LOWER AND E UPPER. THIS GETS THE LES GOING AS THE
850 MB TEMPERATURES FALL TO AROUND -10C BY 00Z. NW TO NNW SNOW BANDS
WILL BEGIN TO FORM. HOWEVER, AS THE CLIPPER MOVES OUT OF THE UPPER
GREAT LAKES, DESPITE THE NORTH TO NNW WIND FLOW AND CHILLY AIR
ACROSS LAKES SUPERIOR AND MICHIGAN, THERE IS VERY DRY AIR TRAILING
THIS SYSTEM AS THE 850-700 MB RH FALLS TO LESS THAN 15% UPSTREAM IN
W UPPER AND WISCONSIN BY 06Z. THE DRY AIR IS OVER THE FORECAST AREA
AS WE GET INTO THE OVERNIGHT, WITH THE RH IN THE LAYER AT 10% OR
LESS BY 12Z. WILL THERE BE SOME SNOW SHOWERS? YES, BUT THE INTENSITY
OF THE SHOWERS SHOULD BE PRETTY LIGHT BY 12Z. SO LIGHT AMOUNTS
DURING THE DAY AS THE SFC LOW MOVES EAST AND MINOR AMOUNTS, MAINLY
NEAR TVC AS THE DRY AIR DIMINISHES THE SNOW SHOWERS.
(1/29)FRIDAY...THERE COULD BE A FEW FLURRIES NEAR TVC AS THE WINDS
CONTINUE TO DIMINISH BUT THE DRY AIR IS FULLY IN CONTROL AND
MINIMIZING THE SNOW PRODUCTION POTENTIAL. SO WILL LEAVE THE MORNING
DRY. AFTER 18Z, THE RIDGE SFC AND 850 MB AXIS MOVES THROUGH THE
REGION. THIS TURNS THE 1000-850 MB LAYER WINDS FROM WNW TO SW IN A
HURRY. BY 00Z, THE WINDS ARE OUT OF THE SW, BUT THE 850 MB
TEMPERATURES IN N LAKE MICHIGAN ARE EXPECTED TO BE -8C(NEAR ST.
IGNACE) OR WARMER. WITH THE WATER TEMPERATURES AROUND +3C THEN WE
DON`T HAVE ENOUGH INSTABILITY TO EVEN GET SOME LAKE ENHANCEMENT
THROUGH THE AFTERNOON. STILL LITTLE TO NO LAKE ENHANCEMENT IN THE
EVENING, BUT THE MAIN SYSTEM IS MOVING INTO THE REGION, WITH THE
WARM FRONT JUST SOUTH OF US AND THE 500 MB SHORTWAVE TROUGH MOVING
INTO THE UPPER GREAT LAKES. THE MODELS HAVE BACKED OFF OF THE SNOW
GETTING INTO E UPPER AND NW LOWER SIGNIFICANTLY. NOW THEY JUST
BARELY GET THE CHANCE FOR SNOW INTO WESTERN MACKINAC COUNTY. FOR MORE
MOST PLACES IT WILL BE A DRY DAY.
AFTER 00Z, THE NEXT CLIPPER, WHICH HAS ITS BAROCLINIC ZONE STRUNG
OUT OVER THE STATE FROM NW TO SE, DROPS INTO THE UPPER GREAT LAKES
AND THE SNOW BEGINS TO SPREAD OVER THE STATE. MOST OF THE FOCUS WILL
BE WITH THE MOISTURE WHICH LOOKS LIKE UPPER MICHIGAN. THIS BEING A
CLIPPER SYSTEM, IT`S PRETTY MOISTURE STARVED, SO THE AMOUNTS SHOULD
REMAIN LIGHT OVER E UPPER AND MINOR TO LIGHT OVER N LOWER.
(1/30)SATURDAY...THE CLIPPER TURNS ITS CORNER NORTH OF LAKE
SUPERIOR, AND BEGINS HEADING EAST INTO QUEBEC BEFORE ITS CORE EVER
GETS TO LAKE SUPERIOR. DRY AIR AT 850 MB WILL PUSH UP INTO THE S
LOWER, AS THE CLIPPER MOVES OUT, AND THE 850 MB TEMPERATURES ARE ON
THE RISE. WINDS REMAIN SW THROUGH THE AFTERNOON, SO WILL EXPECT THE
SYSTEM PRECIPITATION (MAINLY SNOW) WILL CONTINUE OUT BY THE
AFTERNOON, AND THE PARTLY CLOUDY SKIES WILL BEGIN TO MOVE INTO THE
FORECAST AREA, BEFORE SUNSET.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 337 PM EST WED JAN 27 2016
THINGS CONTINUE TO LOOK ACTIVE THROUGH THE EXTENDED PERIOD. A BRIEF
WARMING AHEAD OF LOW PRESSURE MOVING OUT OF THE PLAINS COULD GET
TEMPS ABOVE FREEZING...RESULTING IN SOME RAIN/MIX PRECIP ON SUNDAY
AHEAD OF ARRIVING SNOW. WILL CONTINUE WITH THE CHANCE POPS THROUGH
THE PERIOD WITH TIMING ISSUES THIS FAR OUT. A SYSTEM IN THE TUE/WED
TIME FRAME IS SHAPING UP TO BE THE MAIN STORY OF THIS EXTENDED. THIS
IS AN IMPRESSIVE LOOKING SYSTEM...WITH A SOUTHERLY TRACK THAT WILL
ENABLE A GOOD TAP OF GULF MOISTURE TO GO ALONG WITH THE STRONG
FORCING. IT IS A BIT EARLY FOR SPECIFICS...BUT THIS IS A STORM TO
KEEP AN EYE ON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1145 PM EST WED JAN 27 2016
DEEPER MOISTURE HAS STRIPPED OUT ALOFT AND THE SNOW IS LESS OF A
CONCERN..OUTSIDE OF PLN WHERE SOME ADDITIONAL HALF INCH OR LESS
ACCUMULATIONS EXPECTED. AREAS OF FREEZING DRIZZLE HAS DEVELOP
ACROSS MUCH OF NRN LOWER...AND LATEST DATA SUGGESTS THAT THIS MAY
EASILY BE THE PREVAILING CONDITION FOR THE NIGHT. THE SYSTEM COLD
FRONT WILL CHANGE THAT...ARRIVING 12-16Z...BRINGING A BURST OF
BETTER SNOWS TO THE NW LOWER AIRPORTS. LOOKS LIKE A RATHER BLAND
DAY OF MVFR CIGS THROUGH THE TAF PERIOD WITH LITTLE IN THE WAY OF
SNOW AFTER THE FRONT PUSHED THROUGH. TEMPERATURES DO NOT GET COLD
ENOUGH FOR LAKE EFFECT UNTIL THURSDAY NIGHT. THIS SNOW LOOKS
MINIMAL AS FAR AS AMOUNTS.
GUSTY S/SW WINDS THROUGH THE NIGHT WITH WIND SHEAR STILL PRESSING
ON. GUSTY AGAIN THROUGH THE REMAINDER OF THE TAF PERIOD AS WINDS
SHIFT OUT OF THE WEST TODAY...AND EVENTUALLY NW BY THURSDAY
EVENING.
&&
.MARINE...
ISSUED AT 337 PM EST WED JAN 27 2016
WINDS AND WAVES WILL REACH GALE FORCE ALONG OUR LAKE MICHIGAN
NEARSHORE AREAS TONIGHT AS SW WINDS STRENGTHEN AHEAD OF LOW PRESSURE
TRACKING JUST NORTH OF MICHIGAN. SCA CRITERIA WINDS AND WAVES ARE
EXPECTED FOR OUR LAKE HURON NEARSHORE AREAS. CONDITIONS MAY APPROACH
GALE FORCE ACROSS PORTIONS OF OUR NEARSHORE AREAS ON THURSDAY AS
WIND SHIFT TO THE NW AND STRENGTHEN ON THE BACK SIDE OF THIS LOW
PRESSURE SYSTEM. LAKE ENHANCED SNOW SHOWERS WILL IMPACT MUCH OF OUR
NEARSHORE AREA THRU THURSDAY...RESULTING IN REDUCED VSBYS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ016>036-
041-042.
LH...SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR LHZ345>349.
LM...GALE WARNING UNTIL 7 AM EST THURSDAY FOR LMZ323-341-342-344>346.
LS...NONE.
&&
$$
UPDATE...DICKSON
NEAR TERM...MLR
SHORT TERM...JSL
LONG TERM...MAYHEW
AVIATION...DICKSON
MARINE...MLR
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1135 PM EST WED JAN 27 2016
.UPDATE...
ISSUED AT 1127 PM EST WED JAN 27 2016
INDEED...SEVERAL REPORTS OF FREEZING DRIZZLE AND SOME COATINGS OF
ICE OUT THERE FOR MOST ALL AREAS OF NRN LOWER AND EVEN SOME
SPOTTIER REPORTS ACROSS EASTERN UPPER. WENT AHEAD AND ISSUED AN
ADVISORY FOR DEVELOPING BLACK ICE/VERY SLIPPERY ROADS...MAINLY ON
UNTREATED ROADS WITH LITTLE TO NO SNOW COVER. A BAND OF DEEPER
MOISTURE IS SLIDING INTO EMMET COUNTY AND EXTENDING UP THROUGH
WESTERN CHIP/MACK. THIS OUT AHEAD OF A WEAK VORT MAX. THIS WILL
RESULT IN SNOW. CONCERN IS FOR THE CHANCE FOR THINGS TO GO BACK TO
FREEZING DRIZZLE AFTER IS PASSES THROUGH. RIGHT NOW...ALL OF NRN
LOWER IN A NEW ADVISORY FOR FREEZING DRIZZLE.
UPDATE ISSUED AT 1049 PM EST WED JAN 27 2016
LATEST WV IMAGERY AND HI RES SOUNDING DATA SHOWS DEEPER MOISTURE
HAS BEEN STRIPPED OUT ALOFT...AND THE TRAPPED LOWER LEVEL MOISTURE
IS ALL UNDER -10C WITH STRONG WINDS HELPING TO DEVELOP AREAS OF
FREEZING DRIZZLE. WILL BE MONITORING FOR A POSSIBLE NEW HEADLINE
FOR ICING.
UPDATE ISSUED AT 943 PM EST WED JAN 27 2016
RATHER SUBSTANTIAL UPDATES THIS EVENING. WAA BAND OF SNOWS THAT
ROLLED THROUGH AMOUNTED TO VERY LITTLE...AND CONDITIONS ARE LESS
THAN MARGINAL FOR THE DEVELOPMENT OF LAKE EFFECT. THERE IS A VORT
MAX SWINGING DOWN INTO FAR NRN LAKE MICHIGAN AND THERE WILL BE A
AN UPTICK IN THE SNOWFALL. THERE WAS SOME CONSIDERATION FOR
KEEPING THE ADVISORIES FOR EASTERN UPPER AND EMMET COUNTY TO TAKE
THIS INTO ACCOUNT. HOWEVER...THE OVERALL COMBINATION OF SNOW AND
WIND ON REDUCED VISIBILITY IS EXPECTED TO BE MUCH LESS. THUS...THE
WINTER WEATHER ADVISORY HAS BEEN CANCELLED. THE CLIPPER`S COLD
FRONT DROPS INTO THE REGION 12-16Z THURSDAY...AND WILL HAVE
MINIMAL EFFECT FOR AREAS AWAY FROM THE LAKES...BUT ACROSS NW LOWER
AND CHIPPEWA COUNTY...A BURST OF SNOW AND REDUCED VISIBILITY IS
LIKELY DUE TO MOISTURE FLUX OFF THE LAKES.
MADE THE APPROPRIATED ADJUSTMENTS TO THE FORECAST...LOWERED
CHANCES FOR SNOW AND LOWERED OVERALL SNOWFALL EXPECTATIONS.
&&
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 337 PM EST WED JAN 27 2016
SURFACE RIDGE AXIS CONTINUES TO EXIT EAST AWAY FROM MICHIGAN THIS
AFTERNOON. UPSTREAM LOW PRESSURE IS NEARING THE ARROWHEAD OF
MINNESOTA...WITH THE TRAILING COLD FRONT EXTENDING SOUTHWARD THRU
THE UPPER MISSISSIPPI VALLEY AND INTO THE CENTRAL PLAINS. LOW LEVEL
SW FLOW/WAA CONTINUES TO STRENGTHEN ACROSS THE WRN GREAT LAKES
REGION BETWEEN THESE TWO SYSTEMS...LIMITING ANY RESIDUAL LAKE EFFECT
PRECIP TO MAINLY FLURRIES ACROSS OUR CWA ATTM.
LATEST BASE REF IMAGES FROM UPSTREAM RADARS SHOW THE LEADING EDGE OF
WIDESPREAD SNOW TAKING SHAPE OVER UPPER MICHIGAN AND WISCONSIN IN
ADVANCE OF THE LOW CENTER AND COLD FRONT. BOTH THE RAP AND THE NAM
SHOW THIS LEADING EDGE REACHING OUR WRN CWA JUST BEFORE 00Z...
QUICKLY SPREADING EASTWARD THRU THE REST OF OUR CWA THEREAFTER. WITH
DELTA T`S OF AROUND 10 DEGREES...SUSPECT LOCATIONS DOWNWIND OF SW
FLOW OFF OF LAKE MICHIGAN (I.E. OUR FAR WRN CWA) MAY VERY WELL SEE
SOME LAKE ENHANCEMENT ONCE INCREASING MID LEVEL MOISTURE BEGINS TO
ACTIVATE SEEDER/FEEDER PROCESSES ALOFT PER LATEST MODEL SOUNDINGS
AND CROSS SECTIONS. WE SHOULD BEGIN TO SEE THIS TAKING SHAPE LATE
THIS AFTERNOON...WITH WIDESPREAD SNOW DEVELOPING EARLY THIS EVENING
ONCE MID LEVELS MOISTEN.
CURRENT WINTER WX ADVISORIES ACROSS ERN UPR AND NW LWR MICHIGAN
REMAIN IN LINE WITH LATEST MODEL TRENDS...AND IN COORDINATION WITH
GRR...WILL KEEP ALL HEADLINES IN TACT. STILL EXPECT A GENERAL 2 TO 4
INCHES OF SNOW FOR THESE AREAS...TAPERING TO LESS THAN AN INCH
ACROSS NE LWR MICHIGAN AWAY FROM ANY LAKE ENHANCEMENT. CERTAINLY THE
GUSTY SW WINDS WILL PRODUCE BLOWING AND DRIFTING SNOW...AND MAKE
OVERALL DRIVING CONDITIONS RATHER HAZARDOUS TONIGHT INTO EARLY
THURSDAY...WHICH DECIDEDLY THROWS THIS EVENT INTO ADVISORY TERRITORY
DESPITE BORDERLINE SNOW AMOUNTS. TEMPS WILL STAY NEARLY STEADY
TONIGHT INTO THE MID TO UPPER 20S THANKS TO WAA AND AMPLE CLOUD
COVER.
&&
.SHORT TERM...(THURSDAY THROUGH SATURDAY)
ISSUED AT 337 PM EST WED JAN 27 2016
FORECAST CHALLENGE: SEVERAL CLIPPER SYSTEMS TO DROP INTO THE UPPER
GREAT LAKES, BRINGING POSSIBLE PRECIPITATION TYPE PROBLEMS, AND LAKE
EFFECT.
(1/28)THURSDAY...THE CLIPPER SYSTEM IS IN EASTERN LAKE SUPERIOR AT
12Z. AS IT MOVES EAST IN THE MORNING, THE SFC PRESSURE GRADIENT
TIGHTENS UP QUITE A BIT BY 18Z, AND WE START GETTING NW WINDS OF 15-
20 KNOTS ACROSS N LOWER AND E UPPER. THIS GETS THE LES GOING AS THE
850 MB TEMPERATURES FALL TO AROUND -10C BY 00Z. NW TO NNW SNOW BANDS
WILL BEGIN TO FORM. HOWEVER, AS THE CLIPPER MOVES OUT OF THE UPPER
GREAT LAKES, DESPITE THE NORTH TO NNW WIND FLOW AND CHILLY AIR
ACROSS LAKES SUPERIOR AND MICHIGAN, THERE IS VERY DRY AIR TRAILING
THIS SYSTEM AS THE 850-700 MB RH FALLS TO LESS THAN 15% UPSTREAM IN
W UPPER AND WISCONSIN BY 06Z. THE DRY AIR IS OVER THE FORECAST AREA
AS WE GET INTO THE OVERNIGHT, WITH THE RH IN THE LAYER AT 10% OR
LESS BY 12Z. WILL THERE BE SOME SNOW SHOWERS? YES, BUT THE INTENSITY
OF THE SHOWERS SHOULD BE PRETTY LIGHT BY 12Z. SO LIGHT AMOUNTS
DURING THE DAY AS THE SFC LOW MOVES EAST AND MINOR AMOUNTS, MAINLY
NEAR TVC AS THE DRY AIR DIMINISHES THE SNOW SHOWERS.
(1/29)FRIDAY...THERE COULD BE A FEW FLURRIES NEAR TVC AS THE WINDS
CONTINUE TO DIMINISH BUT THE DRY AIR IS FULLY IN CONTROL AND
MINIMIZING THE SNOW PRODUCTION POTENTIAL. SO WILL LEAVE THE MORNING
DRY. AFTER 18Z, THE RIDGE SFC AND 850 MB AXIS MOVES THROUGH THE
REGION. THIS TURNS THE 1000-850 MB LAYER WINDS FROM WNW TO SW IN A
HURRY. BY 00Z, THE WINDS ARE OUT OF THE SW, BUT THE 850 MB
TEMPERATURES IN N LAKE MICHIGAN ARE EXPECTED TO BE -8C(NEAR ST.
IGNACE) OR WARMER. WITH THE WATER TEMPERATURES AROUND +3C THEN WE
DON`T HAVE ENOUGH INSTABILITY TO EVEN GET SOME LAKE ENHANCEMENT
THROUGH THE AFTERNOON. STILL LITTLE TO NO LAKE ENHANCEMENT IN THE
EVENING, BUT THE MAIN SYSTEM IS MOVING INTO THE REGION, WITH THE
WARM FRONT JUST SOUTH OF US AND THE 500 MB SHORTWAVE TROUGH MOVING
INTO THE UPPER GREAT LAKES. THE MODELS HAVE BACKED OFF OF THE SNOW
GETTING INTO E UPPER AND NW LOWER SIGNIFICANTLY. NOW THEY JUST
BARELY GET THE CHANCE FOR SNOW INTO WESTERN MACKINAC COUNTY. FOR MORE
MOST PLACES IT WILL BE A DRY DAY.
AFTER 00Z, THE NEXT CLIPPER, WHICH HAS ITS BAROCLINIC ZONE STRUNG
OUT OVER THE STATE FROM NW TO SE, DROPS INTO THE UPPER GREAT LAKES
AND THE SNOW BEGINS TO SPREAD OVER THE STATE. MOST OF THE FOCUS WILL
BE WITH THE MOISTURE WHICH LOOKS LIKE UPPER MICHIGAN. THIS BEING A
CLIPPER SYSTEM, IT`S PRETTY MOISTURE STARVED, SO THE AMOUNTS SHOULD
REMAIN LIGHT OVER E UPPER AND MINOR TO LIGHT OVER N LOWER.
(1/30)SATURDAY...THE CLIPPER TURNS ITS CORNER NORTH OF LAKE
SUPERIOR, AND BEGINS HEADING EAST INTO QUEBEC BEFORE ITS CORE EVER
GETS TO LAKE SUPERIOR. DRY AIR AT 850 MB WILL PUSH UP INTO THE S
LOWER, AS THE CLIPPER MOVES OUT, AND THE 850 MB TEMPERATURES ARE ON
THE RISE. WINDS REMAIN SW THROUGH THE AFTERNOON, SO WILL EXPECT THE
SYSTEM PRECIPITATION (MAINLY SNOW) WILL CONTINUE OUT BY THE
AFTERNOON, AND THE PARTLY CLOUDY SKIES WILL BEGIN TO MOVE INTO THE
FORECAST AREA, BEFORE SUNSET.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 337 PM EST WED JAN 27 2016
THINGS CONTINUE TO LOOK ACTIVE THROUGH THE EXTENDED PERIOD. A BRIEF
WARMING AHEAD OF LOW PRESSURE MOVING OUT OF THE PLAINS COULD GET
TEMPS ABOVE FREEZING...RESULTING IN SOME RAIN/MIX PRECIP ON SUNDAY
AHEAD OF ARRIVING SNOW. WILL CONTINUE WITH THE CHANCE POPS THROUGH
THE PERIOD WITH TIMING ISSUES THIS FAR OUT. A SYSTEM IN THE TUE/WED
TIME FRAME IS SHAPING UP TO BE THE MAIN STORY OF THIS EXTENDED. THIS
IS AN IMPRESSIVE LOOKING SYSTEM...WITH A SOUTHERLY TRACK THAT WILL
ENABLE A GOOD TAP OF GULF MOISTURE TO GO ALONG WITH THE STRONG
FORCING. IT IS A BIT EARLY FOR SPECIFICS...BUT THIS IS A STORM TO
KEEP AN EYE ON.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 642 PM EST WED JAN 27 2016
VERY DIFFICULT FORECAST AND CONFIDENCE IS FAIRLY LOW.
SOLID MVFR CIGS ARE STARTING TO ERODE FROM THE WEST WHERE CLOUD
LAYER WAA WAS OCCURRING. WE CONTINUE TO WAA INTO THAT LAYER WHILE
WINDS/WIND SHEAR INCREASE THROUGH THE EVENING. GOTTA BELIEVE THE
WAA AND STRONGER WINDS/MIXING WILL KEEP CIGS VFR UNTIL OVERNIGHT
WHEN A SFC TROUGH FROM WISCONSIN BRINGS MORE WIDESPREAD MVFR. A
TIGHTLY WOUND UP ALBERTA CLIPPER IS QUICKLY BRINGING IN THE
STRONGER WINDS...AS WELL AS A BAND OF WAA SNOWS. CONFIDENCE LESS
THAN AVERAGE ON THE VSBY IMPACT OF THE LIGHT SNOW AND WIND
COMBINATION THAT ARRIVES 01Z-03Z. WILL CONTINUE TO RIDE LATEST
FORECAST IDEAS...BUT THOUGHTS ARE SWIRLING THAT MAYBE VSBYS WILL
NOT BE AS BAD. LAKE CONTRIBUTIONS ARE MARGINAL...BUT HI RES DATA
SUGGESTS THAT IT`S ENOUGH TO KEEP SNOW AND BLOWING SNOW GOING
ACROSS NW LOWER THROUGH THE NIGHT. LATE TONIGHT INTO THURSDAY
MORNING WE WILL HAVE A COLD FRONT PLOW THROUGH BRINGING A BONA
FIDE PERIOD OF SNOW. LOW LEVEL CAA DOESN`T EVEN APPEAR TO BE
ENOUGH FOR LAKE EFFECT SNOWS UNTIL THURSDAY NIGHT.
GONNA RIDE 1-3 INCHES ACROSS NW LOWER THROUGH TONIGHT WITH ANOTHER
INCH THURSDAY. SNOWFALL RATES LOW WITH SNOW RATIOS 13-15:1.
&&
.MARINE...
ISSUED AT 337 PM EST WED JAN 27 2016
WINDS AND WAVES WILL REACH GALE FORCE ALONG OUR LAKE MICHIGAN
NEARSHORE AREAS TONIGHT AS SW WINDS STRENGTHEN AHEAD OF LOW PRESSURE
TRACKING JUST NORTH OF MICHIGAN. SCA CRITERIA WINDS AND WAVES ARE
EXPECTED FOR OUR LAKE HURON NEARSHORE AREAS. CONDITIONS MAY APPROACH
GALE FORCE ACROSS PORTIONS OF OUR NEARSHORE AREAS ON THURSDAY AS
WIND SHIFT TO THE NW AND STRENGTHEN ON THE BACK SIDE OF THIS LOW
PRESSURE SYSTEM. LAKE ENHANCED SNOW SHOWERS WILL IMPACT MUCH OF OUR
NEARSHORE AREA THRU THURSDAY...RESULTING IN REDUCED VSBYS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ016>036-
041-042.
LH...SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR LHZ345>349.
LM...GALE WARNING UNTIL 7 AM EST THURSDAY FOR LMZ323-341-342-344>346.
LS...NONE.
&&
$$
UPDATE...DICKSON
NEAR TERM...MLR
SHORT TERM...JSL
LONG TERM...MAYHEW
AVIATION...DICKSON
MARINE...MLR
AREA FORECAST DISCUSSION
NWS DULUTH MN
612 PM CST FRI JAN 29 2016
.UPDATE...
ISSUED AT 600 PM CST FRI JAN 29 2016
STRONG WAA WAS OCCURRING WITH THE LLJ EARLY THIS EVENING ALONG
WITH A SHORTWAVE DIVING INTO MINNESOTA PER LATEST WATER VAPOR
IMAGERY. THESE FEATURES WERE PRODUCING GOOD LIFT FOR A WINTRY MIX
OF SLEET...FREEZING RAIN AND SNOW ACROSS MUCH OF THE NORTHLAND
THIS EVENING. WE ISSUED A WINTER WEATHER ADVISORY FOR MUCH OF THE
AREA THIS EVENING. MN DOT REPORTING MANY ROADS ACROSS NORTHEAST
MINNESOTA WERE ICE COVERED OR PARTIALLY ICE COVERED AND WE EXPECT
THAT TO OCCUR ACROSS PORTIONS OF NORTHWEST WISCONSIN AS WELL.
THE NAM AND SEVERAL OF THE HIGH RES MODELS WERE DEPICTING THE
PRECIP COVERAGE FAIRLY WELL...AND THEY HAVE THE BULK OF THE PRECIP
MOVING OFF AROUND MIDNIGHT...LINGERING A BIT LONGER OVER THE TIP
OF THE ARROWHEAD AND OVER OUR FAR EASTERN WISCONSIN ZONES.
HOWEVER...THEY MODELS DO SEEM TO BE UNDERDOING THE AMOUNT OF WARM
AIR ALOFT AND WE ADJUSTED THE GRIDS FOR MORE FREEZING RAIN THROUGH
THE EARLY EVENING HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 310 PM CST FRI JAN 29 2016
A 40-50 KNOT LOW LEVEL JET WILL CONTINUE TO USHER INCREASING
MOISTURE AND WARMING MID LEVEL TEMPERATURES INTO THE WESTERN LAKE
SUPERIOR REGION THIS EVENING. LATEST RUC ANALYSIS SHOWS AN AREA OF
INCREASING RADAR RETURNS IS CO-LOCATED WITH A CORRIDOR OF MAX
850PHA TEMPS AND PWATS EXCEEDING A HALF INCH OVER NORTHWEST
MINNESOTA. THE AREA OF FORCING AHEAD OF THE UPPER LEVEL
TROUGH/VORT MAX AND PRECIPITATION WILL SPREAD EAST OVER THE
NORTHLAND THROUGH THE NIGHT.
SHORT TERM FOCUS ON PRECIPITATION TYPE AND LIGHT ICE
ACCUMULATIONS OVERNIGHT. ANTICIPATING SURFACE TEMPERATURES TO RISE
A FEW DEGREES THROUGH THE EVENING...DUE TO THE STRONG WARM AIR
ADVECTION. HOWEVER...THERE IS UNCERTAINTY IF TEMPERATURES WILL
WARM ENOUGH TO SUPPORT ALL RAIN FOR MOST AREAS...OR WILL REMAIN MIX
WITH SLEET/FREEZING RAIN FOR THE EVENING. LATEST NAMBUF SOUNDINGS
SHOW PROFILES SUGGEST A FEW HOUR PERIOD OF A WINTRY MIX LATE
TODAY...BEFORE DEEPLY SATURATING AND SUPPORTING ALL SNOW AFTER
1000PM-MIDNIGHT BEHIND THE FRONTAL PASSAGE. AT THIS TIME THE MAIN
THREAT FOR LIGHT ICE ACCUMULATIONS IS FROM THE TWIN PORTS...SOUTH
ALONG THE INTERSTATE 35 CORRIDOR...AND EAST ACROSS NORTHERN
WISCONSIN. PRIMARILY SNOW...WITH LIGHT ACCUMULATIONS OF AN INCH
OR TWO CAN BE EXPECTED IN THE MINNESOTA ARROWHEAD ZONES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 310 PM CST FRI JAN 29 2016
.LONG TERM...
THE LONG TERM PERIOD IS SHAPING UP TO BE QUITE ACTIVE ACROSS THE
NORTHLAND...WITH A COUPLE MAJOR WEATHER SYSTEMS AFFECTING THE REGION
THROUGHOUT THE PERIOD. ON SATURDAY NIGHT...THE FIRST SYSTEM WILL
MOVE INTO THE CENTRAL PLAINS. THE NAM AND GFS ARE IN THE BEST
AGREEMENT...BRINGING THE SURFACE LOW TO JUST SOUTH OF GREEN BAY BY
00Z MONDAY ON BOTH MODELS. THE ECMWF IS DEFINITELY THE OUTLIER WITH
THIS SYSTEM. HAVE INCREASED POPS ACROSS THE SE 1/2 TO 2/3 OF THE
CWA...ALTHOUGH THE BEST CHANCE OF SEEING A WINTRY MIX FOLLOWED BY
SNOW SATURDAY NIGHT AND SUNDAY. COULD SEE SOME SNOW ACCUMULATION
DURING THAT PERIOD...WITH LESS THAN AN INCH IN NE MN...AND 1 TO 3
INCHES IN NW WI. THE FOCUS WILL SHIFT TO THE SOUTH SHORE OF LAKE
SUPERIOR MONDAY AND MONDAY NIGHT...AS HIGH PRESSURE BUILDS IN AND
WINDS BECOME MORE NORTHERLY. THE BIG STORY FOR THE EXTENDED TIME
PERIOD WILL BE THE POTENTIAL FOR LOCALLY HEAVY SNOW AND INTENSE
WINDS ON TUESDAY AND TUESDAY NIGHT. THE MODELS ARE IN BETTER
CONSENSUS REGARDING THIS SYSTEM...WITH THE GREATEST POTENTIAL FOR
SNOW ACCUMULATION ACROSS OUR NW WI AREA. THE ECMWF BRINGS THE LEAST
SNOW TO NW WI...WHILE THE GFS BRINGS THE MOST. WILL CONTINUE TO HIT
NW WI HARDEST...ALTHOUGH IT DOES APPEAR THAT THE HEAVIEST SNOW WILL
BE EVEN A BIT SOUTH OF OUR CWA. STILL A BIT TOO EARLY TO TELL FOR
SURE...BUT A MAJOR WINTER STORM HAS THE POTENTIAL TO COME CLOSE TO
OUR CWA...IF NOT INTO A PORTION OF OUR CWA. SEVERAL INCHES OF SNOW
WILL BE POSSIBLE ACROSS MUCH OF WISCONSIN. GENERALLY SMALL CHANCES
OF SNOW WILL BE POSSIBLE DURING THE LATTER PART OF THE UPCOMING WORK
WEEK. HIGH TEMPERATURES WILL RANGE FROM THE 30S FOR MOST AREAS ON
SUNDAY...TO THE TEENS AND 20S FOR THE REST OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 600 PM CST FRI JAN 29 2016
STRONG WAA AND A SHORTWAVE WERE COMBING TO PRODUCE MVFR CEILINGS
WITH OCCASIONAL IFR VSBYS THIS EVENING AND A WINTRY MIX OF
FREEZING RAIN...SLEET AND SNOW. WE DO EXPECT MUCH OF THE
PRECIPITATION WILL END BY 06Z...THEN CEILINGS WILL RISE TO VFR
FOR MOST AREAS FROM WEST TO EAST AFTER THAT.
MAINLY VFR CONDITIONS ARE EXPECTED ON SATURDAY...WITH THE
EXCEPTION OF MVFR CEILINGS ALONG THE INTERNATIONAL BORDER.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 27 38 25 32 / 80 10 20 20
INL 30 35 22 26 / 60 10 0 10
BRD 28 38 25 31 / 60 10 10 20
HYR 26 40 28 34 / 70 10 40 50
ASX 26 43 28 34 / 60 10 30 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 11 PM CST THIS EVENING FOR WIZ001-
006-007.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
WIZ002>004-008-009.
MN...WINTER WEATHER ADVISORY UNTIL 11 PM CST THIS EVENING FOR MNZ018-
019-026-035>038.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ012-
020-021.
LS...NONE.
&&
$$
UPDATE...MELDE
SHORT TERM...GRANING
LONG TERM...DAP
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1145 PM CST WED JAN 27 2016
.UPDATE...
ISSUED AT 926 PM CST WED JAN 27 2016
RAIN FALLING FROM THE BRAINERD LAKES EASTWARD TO MUCH OF NW WI.
THE EXCEPTION BEING RIGHT ALONG THE SOUTH SHORE OF LAKE SUPERIOR
NEAR CORNUCOPIA WHERE SNOW WAS REPORTED BY AN OBSERVER. LIGHT SNOW
FALLING NORTH OF U.S. HIGHWAY 2 IN NE MN WHERE TEMPS SUPPORT THE
SNOW. CAA BEGINNING IN THE 925MB LAYER IN NW WI TO THE TWIN PORTS.
WILL SEE THE RAIN CHANGE OVER TO SNOW BY MIDNIGHT. AS THE
VERTICALLY STACKED SFC/UPPER LOW MOVES EASTWARD...THE PCPN WILL
GRADUALLY END OVERNIGHT. UPDATED TO SHOW THIS TREND.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 331 PM CST WED JAN 27 2016
CURRENT RADAR/SATELLITE IMAGERY SHOWS A WELL DEFINED LOW PRESSURE
CENTER POSITIONED ALONG THE INTERNATIONAL BORDER...TRACKING INTO
THE MN ARROWHEAD. SPOTTERS ACROSS THE IN IRON RANGE HAVE REPORTED
ABOUT AN HOUR OF A WINTRY OF SNOW/FREEZING RAIN OR SLEET THIS
AFTERNOON...FOUND JUST AHEAD OF THE SFC LOW. HAVE INTRODUCED
FREEZING DRIZZLE FOR THE ARROWHEAD ZONES THROUGH MIDNIGHT TO
ACCOUNT FOR THE TRACK OF THE LOW.
FURTHER SOUTH...LATEST SPC RUC 925MB ANALYSIS SHOWS A STRONG PUSH
OF WARM AIR ADVECTION FROM THE WEST...ALLOWING TEMPERATURES THIS
AFTERNOON TO RAPIDLY RISE INTO THE UPPER 30 TO AROUND 40 ACROSS
THE BRAINERD LAKES REGION. THE WARM SLOT WILL CONTINUE TO PUSH
EAST OVER THE FORECAST AREA THROUGH THE EVENING...WITH OUR DAYTIMES
HIGHS LIKELY TO BE MET AFTER SUNSET AS TEMPERATURES WILL NOT BEGIN
TO FALL UNTIL THE LOW MAKES IT WAY FAR ENOUGH EAST THE COLD AIR
CAN DROP INTO THE REGION.
CONTINUE TO CARRY SMALL POPS/FLURRIES ON THURSDAY AS THE CYCLONIC
FLOW COMBINED WITH 500MB TEMPS APPROACHING -30C LINGER OVER THE
FORECAST AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 331 PM CST WED JAN 27 2016
THURSDAY NIGHT...SURFACE HIGH PRESSURE WILL BE OVER THE NORTHLAND
THURSDAY EVENING. THE VERY LIGHT WINDS AND PARTIAL CLEAR SKIES COULD
WILL HELP TEMPERATURES DROP WELL DURING THE EVENING...DESPITE
WARMING TEMPERATURES LATER IN THE NIGHT WHEN SSE WINDS DEVELOP AND
HIGH CLOUD COVER MOVES IN FROM THE NORTH AND WEST. LOWS SHOULD RANGE
FROM THE SINGLE DIGITS BELOW ZERO NEAR THE GUNFLINT TRAIL...TO
AROUND 20 DEGREES NEAR THE BRAINERD LAKES REGION.
FRIDAY/FRIDAY NIGHT...AN UPPER LEVEL RIDGE WILL MOVE INTO THE UPPER
MIDWEST AND WESTERN GREAT LAKES REGION...BRINGING WARMER AIR INTO
THE REGION. SOUTHERLY FLOW WILL BRING 850 HPA TEMPERATURES OF UP TO
A FEW DEGREES ABOVE ZERO ACROSS THE SOUTHERN AND SW FORECAST AREA.
HIGH TEMPERATURES WILL CLIMB TO THE LOWER 30S. IT COULD BE
HIGHER...IF IT WERE NOT FOR THE INCREASING CLOUD COVER AND THEN PCPN
THAT WILL COME FROM A CLIPPER SYSTEM THAT WILL BE MOVING ESE ACROSS
CENTRAL MANITOBA AND NW ONTARIO. THE MODELS ARE IN FAIRLY GOOD
AGREEMENT WITH THE RELATED PCPN...EXCEPT THE ECMWF IS A BIT
WETTER...FASTER...AND MORE SOUTH THAN THE GFS/CANADIAN/NAM. WHILE
THE NORTHERN AND EASTERN FORECAST AREA SHOULD PRIMARILY GET
SNOW...THERE COULD BE PERIODS OF MIXED PCPN ACROSS THE SW AND
SOUTHERN FORECAST AREA...POSSIBLY SLEET AND FREEZING RAIN. THIS
THREAT WILL NEED TO BE EXAMINED MORE CLOSELY OVER COMING SHIFTS.
SNOW COULD LINGER THROUGH FRIDAY NIGHT AS THE UPPER LEVEL TROUGH AND
SHORTWAVE MOVE THROUGH THE REGION. THE NORTHERN AND EASTERN FORECAST
AREA WILL LIKELY GET A TOTAL OF 1 TO 3 INCHES...WITH THE GREATEST
AMOUNTS ACROSS THE ARROWHEAD. THE GUNFLINT TRAIN...NE BOUNDARY
WATERS...AND FAR NORTH SHORE COULD GET AROUND 4 TO 5 INCHES.
SATURDAY...MORE ZONAL FLOW AND SOME PARTIAL SUNSHINE IN THE MORNING
SHOULD HELP TEMPERATURES REACH THE LOW TO MIDDLE 30S.
SATURDAY NIGHT AND SUNDAY...A LOW PRESSURE SYSTEM WILL ORGANIZE AND
DEEPEN OVER THE WESTERN GREAT LAKES REGION AS AN UPPER LEVEL TROUGH
DIGS THROUGH THE NORTHERN PLAINS AND UPPER MIDWEST. LIGHT SNOW IS
POSSIBLE ACROSS THE NORTHLAND...WITH THE BEST CHANCES ACROSS THE FAR
SE FORECAST AREA. TEMPERATURES WILL BE A BIT COLDER SUNDAY BECAUSE
OF THE COLDER AIR THAT WILL FILTER IN BEHIND THE PASSING UPPER LEVEL
TROUGH.
MONDAY THROUGH WEDNESDAY...THE COOLING TREND WILL CONTINUE INTO THE
MIDDLE OF THE WEEK. THERE IS INCREASING CONFIDENCE THAT THE
NORTHLAND WILL BE AFFECTED BY A STORM SYSTEM DURING THE MIDDLE OF
THE WEEK...PRIMARILY THE TUESDAY NIGHT AND WEDNESDAY TIME FRAME. THE
THE GFS/CANADIAN/ECMWF ARE CONTINUING TO AN UPPER LEVEL LOW OVER THE
SOUTHERN ROCKY MOUNTAINS WILL FORM A STACKED LOW NEAR THE TEXAS
PANHANDLE ON MONDAY...AND LIFT THROUGH THE PLAINS MONDAY NIGHT AND
TUESDAY. THE GFS AND ECMWF TAKE THE LOW THROUGH NORTHERN ILLINOIS
AND SOUTHERN WISCONSIN TUESDAY NIGHT...SPREADING CONSIDERING PCPN
ACROSS THE NORTHLAND TUESDAY NIGHT AND WEDNESDAY...PRIMARILY OVER
THE SOUTHERN AND EASTERN FORECAST AREA. IT APPEARS PLENTY COLD
ENOUGH FOR SNOWFALL DUE TO THE WRAP AROUND COLD AIR COMING DOWN FROM
CANADA. OUR OFFICE WILL NEED TO INCREASE OUR ATTENTION ON THIS
POTENTIAL STORM SYSTEM OVER THE COMING DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1145 PM CST WED JAN 27 2016
MAINLY MVFR AT THE START OF THE FORECAST WITH SOME PATCHES OF VFR
AND IFR. VERTICALLY STACKED SYSTEM WILL CONTINUE TO MOVE EAST
OVERNIGHT. PCPN WILL BECOME ALL SNOW AS COLDER AIR WORKS ITS WAY
ACROSS THE TERMINALS. THE SNOW WILL GRADUALLY END BY 12Z AS WELL
AS THE GUSTY WINDS. CIGS WILL IMPROVE TO VFR IN THE AFTERNOON AS
HIGH PRESSURE ARRIVES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 27 12 30 / 80 10 0 60
INL 22 22 10 33 / 80 40 30 80
BRD 28 29 19 34 / 20 10 10 40
HYR 27 27 13 32 / 50 30 0 40
ASX 27 27 12 31 / 80 60 10 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...GRANING
LONG TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS BUFFALO NY
646 AM EST THU JAN 28 2016
.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK ACROSS THE REGION TODAY BRINGING LIGHT
SNOW SHOWERS THAT TRANSITION TO LAKE EFFECT SNOW SHOWERS EAST AND
SOUTHEAST OF THE LAKES TONIGHT INTO FRIDAY. LOOKING FARTHER AHEAD...
A PROGRESSIVE WEATHER PATTERN WILL BRING A PARADE OF LOW PRESSURE
SYSTEMS ACROSS THE REGION THROUGH NEXT WEEK. THIS WILL BRING PERIODS
OF WARMER AND COOLER TEMPERATURES ALONG WITH CHANCES FOR RAIN AND
SNOW SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A FAIRLY VIGOROUS SHORTWAVE ACROSS LAKE SUPERIOR THIS MORNING WILL
GRADUALLY SHIFT ACROSS SOUTHERN ONTARIO PROVINCE THROUGH TONIGHT.
A WEAK SURFACE LOW REFLECTION FROM THIS WILL TAKE A SIMILAR
TRACK AND IT WILL DROP A COLD FRONT ACROSS THE REGION LATE
TONIGHT.
AT DAYBREAK RADAR SHOWS VERY LIGHT RETURNS ACROSS SOUTHERN
ONTARIO AND LAKE ERIE...WHICH IS ALIGNED WITH A WEAK MID- LEVEL
WAVE. THIS IS WELL DEPICTED BY A CONSENSUS OF QPF GUIDANCE WITH A
HIGH CONFIDENCE IN LIGHT PRECIPITATION BUT UNCERTAINTY STEMMING
FROM WHETHER IT WILL BE HEAVY ENOUGH TO BE MEASURABLE. RADAR
TRENDS AND THE LATEST HRRR SUPPORT LIKELY POPS...BUT EVEN SO
THIS WILL ONLY BRING A DUSTING OF SNOW THIS MORNING. AFTER THIS A
DRY SLOT SHOULD MOVE IN WHICH WILL RESULT IN MAINLY DRY CONDITIONS
THIS AFTERNOON. TEMPERATURES WILL BE A BIT WARMER THAN YESTERDAY
BUT IT WILL BE BREEZY ACROSS THE NIAGARA FRONTIER WITH GUSTS TO 35
MPH.
THERE IS A BETTER CHANCE FOR SNOW TONIGHT WHEN THE SURFACE LOW AND
SHORTWAVE WILL CROSS THE REGION. AHEAD OF THE SYSTEM 850MB
TEMPERATURES WILL BE ABOUT -5C...BUT THESE ARE FORECAST TO DROP
TO AROUND -10C BY DAYBREAK FRIDAY. LIFT WILL MAINLY STEM FROM THE
SHORTWAVE AND SURFACE COLD FRONT THIS EVENING WHICH WILL BRING A
PERIOD OF SNOW TO MOST AREAS BUT ONLY LIGHT ACCUMULATION OF AN
INCH OR SO. LATER TONIGHT THERE WILL BE SOME LAKE ENHANCEMENT AS
TEMPERATURES ALOFT COOL...BUT LAKE INDUCED INSTABILITY WILL BE
LIMITED. UPSLOPING IN THE WESTERLY FLOW WILL ALSO PROVIDE SOME
ENHANCEMENT. SOME HIGH RESOLUTION GUIDANCE (00Z ARW/NMM/RGEM)
SHOW A LAKE HURON CONNECTION...BUT THERE IS UNCERTAINTY IF AND WHERE
THIS WILL OCCUR. IT IS POSSIBLE AMOUNTS EAST OF LAKE ERIE WILL
REACH ADVISORY CRITERIA BUT FORECAST CONFIDENCE IS SHY OF ISSUING
ANY HEADLINES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
FRIDAY MORNING WILL OPEN WITH A CLIPPER SYSTEM JUST TO THE NORTHEAST
OF LAKE ONTARIO...WITH LINGERING WIDESPREAD LIGHT SYNOPTIC SNOWS
ACROSS THE EASTERN LAKE ONTARIO REGION. THE SNOW EAST OF LAKE
ONTARIO WILL LIKELY LINGER THROUGH MUCH OF THE DAY AS NORTHWEST
UPSLOPE FLOW MAINTAINS LIGHT SNOW ACTIVITY THROUGH THE DAY. FARTHER
WESTWARD LINGERING ABUNDANT LOW LEVEL MOISTURE AND COOLING 925-850
HPA TEMPERATURES WILL BE CONDUCIVE FOR LAKE EFFECT SNOW...WITH A
NORTHWEST WIND FOCUSING THE SNOWS SOUTHEAST OF LAKE ERIE. THROUGH
THE DAY UNDER COLD AIR ADVECTION...AIR TEMPERATURES AT 925 HPA WILL
DROP TO NEAR -10C EAST OF BOTH LAKES...AND EXPECT LAKE SNOWS TO
DEVELOP EAST AND SOUTHEAST OF LAKE ONTARIO AS WELL. THIS WEST TO
NORTHWEST FLOW WILL ALSO GENERATE UPSLOPE SNOW SHOWERS FAVORING THE
CHAUTAUQUA RIDGE...AND THE TUG HILL REGION. IT IS THESE UPSLOPE
REGIONS OF THE CHAUTAUQUA RIDGE...AND EAST OF LAKE ONTARIO THAT
COULD NEAR 4 INCH SNOWFALL ACCUMULATIONS. WILL MENTION THIS
POTENTIAL MODERATE SNOW EVENT IN THE HWO PRODUCT. OTHERWISE SNOWFALL
FRIDAY WILL BE JUST AN INCH OR LESS OUTSIDE OF THESE FAVORED LAKE
EFFECT AND NORTH COUNTRY UPSLOPE AREAS.
AS NOTED WITH THE COLD AIR ADVECTION BEHIND THE UPPER LEVEL
SHORTWAVE AIR TEMPERATURES FRIDAY WILL BE SEASONABLY COOL WITH HIGHS
IN THE LOW TO MID 20S. A STIFF BREEZE WILL BRING WIND CHILLS IN THE
SINGLE DIGITS TO LOWER TEENS ACROSS THE REGION DURING THE DAY.
FRIDAY NIGHT BOTH A SURFACE AND MID LEVEL RIDGE AXIS WILL CROSS THE
REGION. THIS WILL END THE LAKE EFFECT SNOWS WITH TRAILING LIGHT
SNOWS GENERAL SOUTHEAST OF LAKE ONTARIO. THESE WILL DIMINISH TO
SCATTERED FLURRIES BY THE END OF THE NIGHT. OTHERWISE THE BULK OF
THE NIGHT SHOULD REMAIN DRY WITH THE BRIEF RIDGE AXIS PASSING ACROSS
THE REGION. THOUGH THERE MAY BE SOME CLEARING EARLY IN THE
NIGHT...CLOUDS WILL INCREASE FROM THE WEST AS YET ANOTHER CLIPPER
LOW NEARS THE REGION. THIS SYSTEM WILL SPREAD AT FIRST LIGHT
SYNOPTIC SNOWS ACROSS THE REGION DURING THE DAY SATURDAY. AS THE
SYSTEM PULLS MUCH WARMER AIR NORTHWARD EXPECT THESE SNOWS TO CHANGE
OVER TO PLAIN RAIN SHOWERS DURING THE DAYTIME. SOUTHERLY WINDS ON
SATURDAY WILL BRING AFTERNOON AIR TEMPERATURES INTO THE MID TO UPPER
30S.
BEHIND THE SHORTWAVE SATURDAY NIGHT WINDS WILL GENERALLY REMAIN
SOUTHERLY AND WITHOUT AN ARCTIC SOURCE AIRMASS SPREADING ACROSS THE
REGION OUR OVERNIGHT LOWS WILL ONLY DROP A FEW DEGREES. MOST AREAS
MAY REMAIN ABOVE FREEZING THROUGH THE NIGHT. SYNOPTIC PRECIPITATION
MAY REMAIN EARLY SATURDAY EVENING EAST OF LAKE ONTARIO...OTHERWISE
NO LAKE EFFECT WILL BE FOUND BEHIND THIS CLIPPER LOW.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
OVERALL PATTERN DURING THE PERIOD REMAINS INTACT WITH BROAD TROUGHING
FOUND OVER THE WESTERN HALF OF THE COUNTRY...SUPPORTING DOWNSTREAM
RIDGING OVER THE GREAT LAKES REGION. THIS PATTERN WILL KEEP A
PERSISTENT MILD SOUTHWEST FLOW ALOFT MAINTAINING A VERY HIGH
CONFIDENCE IN MUCH ABOVE NORMAL TEMPERATURES DURING THIS PERIOD.
TEMPERATURES SUNDAY THROUGH WEDNESDAY MAY REACH INTO THE 40S EACH
DAY...AND POSSIBLY NEAR 50F BOTH SUNDAY AND WEDNESDAY AHEAD OF
STORM SYSTEMS CROSSING THE CENTRAL GREAT LAKES.
THE LEAD PACIFIC SHORTWAVE AND FRONTAL SYSTEM WILL PUSH INTO THE
REGION LATE SUNDAY AND MONDAY BRINGING INCREASING CHANCES FOR
PRECIPITATION...MOST LIKELY IN THE FORM OF RAIN SHOWERS.
THE MAIN WEATHER FEATURE DURING THIS PERIOD WILL BE THE DEVELOPING
SIGNIFICANT STORM SYSTEM EMERGING FROM THE MID MISSISSIPPI VALLEY
INTO A DEEP SURFACE CYCLONE OVER THE WESTERN GREAT LAKES BY
WEDNESDAY. LATEST MODEL CONSENSUS ALL SIMILAR IN THEIR TRACK OF THIS
SYSTEM...KEEPING OUR REGION ON THE WARM SIDE BRINGING WIDESPREAD
RAIN AND WINDY CONDITIONS.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A MID-LEVEL WAVE WILL MOVE ACROSS THE REGION THIS MORNING WITH
SOME LIGHT SNOW AND A PERIOD OF MVFR CONDITIONS. VSBY MAY BRIEFLY
LOWER TO 2 SM...BUT OVERALL THIS WAVE WILL HAVE A LIMITED IMPACT
ON AVIATION.
EXPECT A DRY SLOT TO MOVE IN THIS AFTERNOON WITH MOSTLY VFR
CONDITIONS. THIS WILL BE SHORT LIVED WHEN LOW PRESSURE AND THE
SHORTWAVE MOVE ACROSS THE REGION THIS EVENING. THIS WILL BRING
STEADY SNOW TO MOST AREAS WITH IFR OR POSSIBLY LOWER CONDITIONS
THIS EVENING AND INTO THE OVERNIGHT PERIOD.
OUTLOOK...
FRIDAY...VFR/MVFR WITH A CHANCE OF SNOW SHOWERS... EXCEPT MVFR/IFR
IN AREAS OF LAKE EFFECT SNOW SOUTHEAST OF THE LAKES.
SATURDAY THROUGH MONDAY...VFR/MVFR WITH A CHANCE OF RAIN AND SNOW
SHOWERS.
&&
.MARINE...
LOW PRESSURE WILL GRADUALLY DROP ACROSS THE GREAT LAKES REGION
THROUGH TONIGHT. AHEAD OF THIS WILL BE A SSW FLOW WHICH WILL SHIFT
TO THE WEST LATE TONIGHT WHEN THE SYSTEM MOVES TO OUR EAST. WINDS
WILL BE MARGINAL TO SMALL CRAFT CRITERIA AHEAD OF THE LOW...WITH
LESSER WINDS/WAVES ACROSS CENTRAL PORTIONS OF LAKE ONTARIO BUT SCA
CONDITIONS EXPECTED FOR THE REST OF THE NEARSHORES.
WAVES WILL BUILD WITH THE WESTERLY FLOW WITH BETTER MIXING FROM THE
COLDER AIR BEHIND THE SYSTEM. THIS PROMPTS SCA HEADLINES FOR ALL THE
LAKESHORES LATE TONIGHT AND FRIDAY. WINDS AND WAVES DIMINISH FRIDAY
NIGHT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
LEZ020.
SMALL CRAFT ADVISORY FROM 3 AM FRIDAY TO 4 AM EST
SATURDAY FOR LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 10 PM EST FRIDAY FOR LOZ042.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SATURDAY FOR LOZ045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...AR
SHORT TERM...THOMAS
LONG TERM...THOMAS/TMA
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS Tulsa OK
930 PM CST FRI JAN 29 2016
.DISCUSSION...
A weak surface boundary will move into the area tonight shifting
the winds to the northwest across parts of eastern Oklahoma. This
boundary will wash out by midday Saturday with south winds
returning to all areas. Temperatures today greatly exceeded
expectations and model low level thermal progs and the latest
experimental HRRR data suggests Saturday will only be a few
degrees cooler than today in northeast Oklahoma, and as warm as
today across southeast Oklahoma and northwest Arkansas. Thus, have
raised high temperatures Saturday by at least 5 degrees
everywhere, and there is a chance this may not be quite warm
enough. Have also made minor adjustments to the overnight low
tonight at KBVO. The rest of the forecast looks good at this
time.
Update on the way.
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...07
LONG TERM....05
PLATE
Area Forecast Discussion
National Weather Service Spokane WA
445 PM PST FRI JAN 29 2016
.SYNOPSIS...
A strong low pressure area will track through the northeast corner
of Washington into extreme north Idaho this evening spreading
widespread snow, with most of the significant accumulations
occurring over the mountains. The low will also deliver windy
conditions to southeast Washington and north central Idaho this
evening. The low will be followed by a trough of low pressure
which will settle into the region Saturday and lingers through
Monday, delivering seasonal temperatures with a chance of snow
showers. A more organized system approach again toward next
Thursday.
&&
.DISCUSSION...
Tonight... Complex forecast will continue into the evening care of
deep surface low and its associated precipitation field. As of
2pm, the center of the low was near Spokane and was heading slowly
to the northeast per isallobaric analysis. Looks like the low will
now head toward the Sandpoint/Bonner Ferry area with most of the
precipitation shield occurring to the north of it. This
precipitation can primarily be attributed to strong isentropic
ascent so the emphasis will shift into the NE corner of Washington
and the northern half of the Idaho between now and sunset.
Precipitation amounts could be impressive over a short time based
on strong ascent through the dendritic layer. So precipitation
chances in this area will be high. While that part of the forecast
will be easy, the difficult part will be the precipitation type.
Model snow levels whether from BUFKIT, 12z and 18z models are all
too high based on observations. Case in point has occurred in
Spokane through the day. None of the models had snow levels any
lower than 3000-3500` this afternoon and yet it`s snowed the
entire event at our office and the Airport. Meanwhile around 500`
lower (at Felts Field) its been mainly rain until 2pm, when the
precipitation also changed to snow. That being said, we have a
hard time trusting the 2000-2500 snow levels advertised by the
models for locations north and east of Spokane. As such we expect
to see mostly snow for locations such as Colville, Sandpoint, and
Bonners Ferry. Precipitation totals could range from 0.15-0.35
inches through this evening over these locations most of which
will fall as snow. The problem is warm road temperatures will keep
most of it from accumulating on the roads so impacts could be
minimal except on lesser traveled roads, grassy surfaces and
elevations above 2000`. It`s possible some valley locations could
see 1-3 of snow, but confidence of a widespread accumulating
snow is too low to issue a winter weather advisory. If this event
were expected to occur several hours later and benefit from sunset
we would have high confidence to issue a winter weather advisory.
Confidence is much higher for moderate snows of 3-6 occurring
over the surrounding mountains. Meanwhile drier and much less
stable air is moving in behind the front and low per the latest
water vapor loops. Showers look like they will persist near the
Cascade Crest through the evening and thus we will let the winter
weather advisory continue, however the main impacts will be more
spotty vs. widespread. Spotty snow showers will also redevelop
overnight near the Blue Mountains, and the Panhandle Mountains.
Most accumulations should be light.
The other story for tonight will be the winds behind the passing
low and trailing cold front. The surface low depth is around 1003
mbs which is still deeper than the 12z and 18z models. The HRRR is
still the closest model to reality and will be followed. This
suggests we have likely seen the peak of the winds on the Palouse
with a 47 mph gust reported at Pullman and 59 mph at Alpowa
Summit but it should remain quite breezy through early evening.
Stronger winds will move into southern portions of the Spokane and
Coeur d`Alene area shortly but wind gusts should peak around 30-35
mph, short of advisory criteria. The surface pressure gradients
will fall rapidly overnight and by 8pm, peak winds will generally
be less than 20 mph. fx
Saturday through Monday: A trough of low pressure settles over the
region cooling and destabilizing the atmosphere delivering
seasonal temperatures and increasing chances for snow showers,
especially in the mountains. The general weather pattern does not
support any major storm systems but the convective nature of the
snow showers does hint at the potential for locally moderate
impacts if showers setup during non-daylight hours. Westerly flow
accompanying the trough will shadow the lee of the Cascades for
the most part focusing a bulk of the snow shower activity across
the Idaho Panhandle and along the Cascade Crest. Consequently,
travel impacts from snow are likely over the Cascade Mtn Passes,
Lookout Pass, US 95, and a majority of the highways across
southern Shoshone County with the potential for 2-6 inches over
the 48 hour period. For much of the Basin, there is a chance for
snow showers on and off but a lot of this activity will depend on
the presence of a vort max or weak circulation which carry low
confidence at this time. Above freezing temperatures during the
afternoon and early evening also indicate that impacts will be
limited to nighttime hours. All locations should prepare for
freezing temperatures and renewed threat for black ice each
morning where moisture is present. /sb
Monday night through Friday: Localized snow chances and cool
temperatures are projected, until a broader threat of precipitation
starts in around the second half of the week. Monday night to
Wednesday the region remains in a northwest flow and at least a
couple shortwaves pass by. One passes Monday night and brings the
primary snow chances to the mountain zones. There could also be
some isolated snow showers or maybe just flurries across the
eastern third of WA, but the risk is low. Otherwise look for some
low clouds and patchy fog over the eastern Columbia Basin. Tuesday
into Tuesday night a second shortwave pushes through. There are
some model differences regarding its impacts. Some runs bring a
broader threat of snow with an inch or two of snow in the
lowlands, especially late and away from the western Columbia
Basin. However at this point that solution, from the GFS, is an
outlier and is not used for the official forecast. The ECMWF, GEM
and DGEX keep the primary snow shower chances in the mountains,
with a secondary threat expanding across southeastern WA and the
lower ID Panhandle. However there is enough evidence to keep at
slight chance over northeast WA too. By Wednesday a ridge starts
to edge in from the west. The threat of some orographic snow
showers will continue in the eastern mountains. Elsewhere look for
some lingering low clouds, again especially east.
Wednesday night the next organized system starts to approach. The
flow above the surface remains southwesterly, which will keep some
orographic snow shower chances in the northern and eastern
mountains. Meanwhile the leading warm front and overrunning snow
threat starts into the Cascades. The low level flow turns
south/southeast and expands stratus back toward the northern and
western Columbia Basin. Some light snow or flurries could also be
squeezed out. Thursday, however, is when the broader precipitation
arrives. Models diverge of how quickly it expands but chances
generally rise through the day and peaking Thursday evening with
the incoming cold front. Temperatures support largely snow, except
perhaps toward the deeper Columbia Basin/L-C Valley where rain or
a rain/snow mix is possible. So impacts from snow accumulations
are possible for some. However these impacts may be limited during
the daylight hours as surface temperatures/road temperatures may
inhibit or hold back accumulations. Additionally the system will
bring another increase in winds, especially late in the day with
the passing cold front. By Friday the region returns to a drier
northwest flow with the primary snow chances retreating to the
mountains. /J. Cote
&&
.AVIATION...
00Z TAFS: Tough aviation forecasts for most sites as strong low
pressure drifts from current position in NE WA near GEG and into
NW MT early this evening. The departing low will shift the main
threat of precipitation away from any of the forecast sites, with
the main problem then trending toward what to do about residual
cloud cover. The latest visible satellite imagery was showing
rapid clearing over the SE corner of WA and the southern Columbia
Basin so the forecasts for PUW LWS MWH and EAT will likely
feature VFR conditions for a while this evening. However there is
a fair chance that stratus redevelops sometime overnight. Just not
sure how high the clouds will be or when they will reform. Then
there is the question how long with the clouds persist into
Saturday. MOS guidance is all over the place so confidence is very
low. Another issue is the winds. LWS and PUW will see the
strongest winds with speeds of 20-30kts and gusts to 30-40kts
expected through 02Z. The most difficult forecasts will be the
GEG-SFF-COE ones. Low clouds will likely persist through most of
the night with IFR conditions, however there is clearing about 60
miles SW of GEG. We suspect some of that clearing could move into
GEG between 02-03z and perhaps to COE shortly thereafter. However
we aren`t confident that any of this clearing will persist long
as moist upslope sw flow behind recent precipitation is notorious
for reforming stratus in a hurry. The question would be would it
be the MVFR or IFR category. Whatever forms will likely persist
through most of the forecast period. fx/LN
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 29 37 25 35 25 34 / 30 20 20 20 20 20
Coeur d`Alene 31 36 27 35 26 33 / 50 40 20 40 20 20
Pullman 32 38 28 36 25 35 / 50 40 20 20 20 40
Lewiston 36 45 33 42 31 40 / 40 40 20 20 20 40
Colville 30 35 27 35 25 33 / 50 20 10 30 20 20
Sandpoint 32 35 28 34 27 32 / 100 40 30 50 30 20
Kellogg 30 33 26 32 25 31 / 90 50 40 50 30 40
Moses Lake 30 42 27 39 26 38 / 10 10 10 10 10 10
Wenatchee 31 39 29 38 28 36 / 10 10 10 10 10 10
Omak 26 35 24 34 23 32 / 10 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory until 8 PM PST this evening for Idaho Palouse-
Lewis and Southern Nez Perce Counties-Lewiston Area.
WA...Wind Advisory until 8 PM PST this evening for Lower Garfield and
Asotin Counties-Northeast Blue Mountains-Washington Palouse.
Winter Weather Advisory until 10 PM PST this evening for East
Slopes Northern Cascades.
&&
$$
AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION CAN BE SEEN AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
259 PM PST FRI JAN 29 2016
.SYNOPSIS...
A strong low pressure area will track through the northeast corner
of Washington into extreme north Idaho this evening spreading
widespread snow, with most of the significant accumulations
occurring over the mountains. The low will also deliver windy
conditions to southeast Washington and north central Idaho this
evening. The low will be followed by a trough of low pressure
which will settle into the region Saturday and lingers through
Monday, delivering seasonal temperatures with a chance of snow
showers. A more organized system approach again toward next
Thursday.
&&
.DISCUSSION...
Tonight... Complex forecast will continue into the evening care of
deep surface low and its associated precipitation field. As of
2pm, the center of the low was near Spokane and was heading slowly
to the northeast per isallobaric analysis. Looks like the low will
now head toward the Sandpoint/Bonner Ferry area with most of the
precipitation shield occurring to the north of it. This
precipitation can primarily be attributed to strong isentropic
ascent so the emphasis will shift into the NE corner of Washington
and the northern half of the Idaho between now and sunset.
Precipitation amounts could be impressive over a short time based
on strong ascent through the dendritic layer. So precipitation
chances in this area will be high. While that part of the forecast
will be easy, the difficult part will be the precipitation type.
Model snow levels whether from BUFKIT, 12z and 18z models are all
too high based on observations. Case in point has occurred in
Spokane through the day. None of the models had snow levels any
lower than 3000-3500` this afternoon and yet it`s snowed the
entire event at our office and the Airport. Meanwhile around 500`
lower (at Felts Field) its been mainly rain until 2pm, when the
precipitation also changed to snow. That being said, we have a
hard time trusting the 2000-2500 snow levels advertised by the
models for locations north and east of Spokane. As such we expect
to see mostly snow for locations such as Colville, Sandpoint, and
Bonners Ferry. Precipitation totals could range from 0.15-0.35
inches through this evening over these locations most of which
will fall as snow. The problem is warm road temperatures will keep
most of it from accumulating on the roads so impacts could be
minimal except on lesser traveled roads, grassy surfaces and
elevations above 2000`. It`s possible some valley locations could
see 1-3 of snow, but confidence of a widespread accumulating
snow is too low to issue a winter weather advisory. If this event
were expected to occur several hours later and benefit from sunset
we would have high confidence to issue a winter weather advisory.
Confidence is much higher for moderate snows of 3-6 occurring
over the surrounding mountains. Meanwhile drier and much less
stable air is moving in behind the front and low per the latest
water vapor loops. Showers look like they will persist near the
Cascade Crest through the evening and thus we will let the winter
weather advisory continue, however the main impacts will be more
spotty vs. widespread. Spotty snow showers will also redevelop
overnight near the Blue Mountains, and the Panhandle Mountains.
Most accumulations should be light.
The other story for tonight will be the winds behind the passing
low and trailing cold front. The surface low depth is around 1003
mbs which is still deeper than the 12z and 18z models. The HRRR is
still the closest model to reality and will be followed. This
suggests we have likely seen the peak of the winds on the Palouse
with a 47 mph gust reported at Pullman and 59 mph at Alpowa
Summit but it should remain quite breezy through early evening.
Stronger winds will move into southern portions of the Spokane and
Coeur d`Alene area shortly but wind gusts should peak around 30-35
mph, short of advisory criteria. The surface pressure gradients
will fall rapidly overnight and by 8pm, peak winds will generally
be less than 20 mph. fx
Saturday through Monday: A trough of low pressure settles over the
region cooling and destabilizing the atmosphere delivering
seasonal temperatures and increasing chances for snow showers,
especially in the mountains. The general weather pattern does not
support any major storm systems but the convective nature of the
snow showers does hint at the potential for locally moderate
impacts if showers setup during non-daylight hours. Westerly flow
accompanying the trough will shadow the lee of the Cascades for
the most part focusing a bulk of the snow shower activity across
the Idaho Panhandle and along the Cascade Crest. Consequently,
travel impacts from snow are likely over the Cascade Mtn Passes,
Lookout Pass, US 95, and a majority of the highways across
southern Shoshone County with the potential for 2-6 inches over
the 48 hour period. For much of the Basin, there is a chance for
snow showers on and off but a lot of this activity will depend on
the presence of a vort max or weak circulation which carry low
confidence at this time. Above freezing temperatures during the
afternoon and early evening also indicate that impacts will be
limited to nighttime hours. All locations should prepare for
freezing temperatures and renewed threat for black ice each
morning where moisture is present. /sb
Monday night through Friday: Localized snow chances and cool
temperatures are projected, until a broader threat of precipitation
starts in around the second half of the week. Monday night to
Wednesday the region remains in a northwest flow and at least a
couple shortwaves pass by. One passes Monday night and brings the
primary snow chances to the mountain zones. There could also be
some isolated snow showers or maybe just flurries across the
eastern third of WA, but the risk is low. Otherwise look for some
low clouds and patchy fog over the eastern Columbia Basin. Tuesday
into Tuesday night a second shortwave pushes through. There are
some model differences regarding its impacts. Some runs bring a
broader threat of snow with an inch or two of snow in the
lowlands, especially late and away from the western Columbia
Basin. However at this point that solution, from the GFS, is an
outlier and is not used for the official forecast. The ECMWF, GEM
and DGEX keep the primary snow shower chances in the mountains,
with a secondary threat expanding across southeastern WA and the
lower ID Panhandle. However there is enough evidence to keep at
slight chance over northeast WA too. By Wednesday a ridge starts
to edge in from the west. The threat of some orographic snow
showers will continue in the eastern mountains. Elsewhere look for
some lingering low clouds, again especially east.
Wednesday night the next organized system starts to approach. The
flow above the surface remains southwesterly, which will keep some
orographic snow shower chances in the northern and eastern
mountains. Meanwhile the leading warm front and overrunning snow
threat starts into the Cascades. The low level flow turns
south/southeast and expands stratus back toward the northern and
western Columbia Basin. Some light snow or flurries could also be
squeezed out. Thursday, however, is when the broader precipitation
arrives. Models diverge of how quickly it expands but chances
generally rise through the day and peaking Thursday evening with
the incoming cold front. Temperatures support largely snow, except
perhaps toward the deeper Columbia Basin/L-C Valley where rain or
a rain/snow mix is possible. So impacts from snow accumulations
are possible for some. However these impacts may be limited during
the daylight hours as surface temperatures/road temperatures may
inhibit or hold back accumulations. Additionally the system will
bring another increase in winds, especially late in the day with
the passing cold front. By Friday the region returns to a drier
northwest flow with the primary snow chances retreating to the
mountains. /J. Cote
&&
.AVIATION...
18Z TAFS: Tough aviation forecasts here based on widespread
precipitation and mixed precipitation types. We expect to see
periods of MVFR conditions and brief IFR conditions as long as the
precipitation shield covers the area. For EAT we expect IFR conditions
to continue through 21z with snow and perhaps some brief rain.
For MWH look for continued MVFR conditions with rain followed by
a similar improvement to EAT. For GEG SFF COE the forecast is much
trickier through 00z. Snow is likely for the GEG while the other
two sites will see rain or a rain snow mix. Cigs will rapidly vary
rapidly as will the vsbys. For the snow periods we expect to
primarily see IFR conditions based on visibilities. Conditions
should improve rapidly once the precipitation ends between 00z-02z
with gusty southwest winds of 30-35kts possible. Now onto LWS and
PUW. The precip here will primarily be rain while cigs vary from
MVFR to VFR. Whats more noteworthy will be a developing wind
situation due to a passing low pressure system. We expect to see
wind gusts from 35-40 kts possible between 22z-00z with the wind
direction turning from east to a sharp turn to the southwest.
Hopefully the cigs will improve with the wind shift but Pullman
can often develop low clouds in these situation. Once we get
beyond 00z the conditions improve for most of the TAF sites. We
should see some mvfr stratus redevelop overnight from GEG-COE but
confidence is low. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 29 37 25 35 25 34 / 30 20 20 20 20 20
Coeur d`Alene 31 36 27 35 26 33 / 50 40 20 40 20 20
Pullman 32 38 28 36 25 35 / 50 40 20 20 20 40
Lewiston 36 45 33 42 31 40 / 40 40 20 20 20 40
Colville 30 35 27 35 25 33 / 50 20 10 30 20 20
Sandpoint 32 35 28 34 27 32 / 100 40 30 50 30 20
Kellogg 30 33 26 32 25 31 / 90 50 40 50 30 40
Moses Lake 30 42 27 39 26 38 / 10 10 10 10 10 10
Wenatchee 31 39 29 38 28 36 / 10 10 10 10 10 10
Omak 26 35 24 34 23 32 / 10 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory until 8 PM PST this evening for Idaho Palouse-
Lewis and Southern Nez Perce Counties-Lewiston Area.
WA...Wind Advisory until 8 PM PST this evening for Lower Garfield and
Asotin Counties-Northeast Blue Mountains-Washington Palouse.
Winter Weather Advisory until 10 PM PST this evening for East
Slopes Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1133 PM CST WED JAN 27 2016
.UPDATE...
ISSUED AT 700 PM CST WED JAN 27 2016
EARLY UPDATE THIS EVENING TO ACCOUNT FOR A LACK OF ANY ONGOING
SNOW FOR AREAS NORTH OF I-94 WHERE WE HAD LIKELY TO CATEGORICAL
POPS ONGOING. PER RADAR TRENDS...JUST NOT SEEING MUCH LIKELY TO
HAPPEN UP THAT WAY THE REST OF THE EVENING...AND LIKELY THROUGH AT
LEAST 2 AM. HOWEVER...DO GET THE FEELING BASED ON THE SETUP THAT
THERE COULD BE A NARROW WINDOW FOR SOME RATHER INTENSE SNOW
SHOWERS TO ROLL SOUTHWARD LATER TONIGHT INTO 9-10 AM TOMORROW
NORTH OF I-90 INTO WISCONSIN COUNTIES ALONG AN INCOMING SHALLOW
BUT RATHER SHARP COLD FRONT. UP UNTIL THAT FEATURE ARRIVES...
DEEPER MOISTURE/FORCING LOOK TO REMAIN CONFINED PRIMARILY NORTH OF
TAYLOR/CLARK COUNTIES WITH NOTHING WORSE THAN A SPRINKLE OR FLURRY
EXPECTED.
HOWEVER...WITH SUCH A PUSH OF SUB-800MB COLD ADVECTION BETWEEN
ROUGHLY 09-15Z...AND AN ASSOCIATED TIGHT LOW LEVEL FRONTOGENETIC
RESPONSE...DON`T HAVE MUCH DIFFICULTY ENVISIONING A BAND OF SNOW
SQUALLS RIDING SOUTHWARD ALONG AND JUST BEHIND THE BOUNDARY. HI-
RES GUIDANCE HAS BEEN PICKING UP ON THIS IDEA THE PAST HANDFUL OF
HOURS AND THE IDEA IS STRONGLY SUPPORTED WITH VERY STEEP LOW LEVEL
LAPSE RATES AND ENHANCED FRONTAL CONVERGENCE...AS EVIDENCED BY
THE SNOW SQUALL PARAMETER REALLY RAMPING UP FOR A TIME. OVERALL...
NOT EXPECTING MUCH IN THE WAY OF ANY ACCUMULATION...BUT THERE IS A
POTENTIAL WINDOW THERE EITHER SIDE OF SUNRISE FOR SOME TRAVEL
IMPACTS GIVEN BRIEF HEAVY RATES WITHIN ANY SQUALLS...NOT TO
MENTION EXPECTED GUSTY NORTHWEST WINDS OF 25-30 KNOTS WITH
EXCELLENT MIXING FOR A TIME IN COLD ADVECTION.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 352 PM CST WED JAN 27 2016
CURRENTLY AS OF 2 PM...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED A POTENT SHORTWAVE IN WESTERN WISCONSIN AND
SOUTHEAST MINNESOTA...WITH ANOTHER ONE QUICKLY ON ITS HEELS NEAR
LAKE WINNIPEG. BOTH WERE DIGGING QUICKLY SOUTHEASTWARD COMING
DOWN A HIGHLY AMPLIFIED RIDGE OVER WESTERN NORTH AMERICA. BANDS OF
PRECIPITATION...MOSTLY IN THE FORM OF SNOW...WERE ACCOMPANYING
BOTH WAVES. DRY AIR EVIDENT ON THE 27.12Z MPX AND ABR RAOBS HAVE
KEPT THE SNOW NORTH OF WISCONSIN 29. SECOND BAND OF SNOW LOCATED
IN NORTHWEST MINNESOTA AHEAD OF THE SHORTWAVE THERE. SOUTHERLY
WINDS HAVE PICKED UP ACROSS THE FORECAST AREA DUE TO TIGHTENING
GRADIENT. THIS HAS RESULTED IN SOME MINOR DRIFTING SNOW AND
BLOWING SNOW ACROSS SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND ON
THE BLUFF TOPS AND OPEN AREAS OF WESTERN WISCONSIN.
THE 27.12Z MODELS ARE IN AGREEMENT THAT THE INITIAL SHORT WAVE
WILL MOVE SOUTHEAST ACROSS THE AREA LATE THIS AFTERNOON AND
EVENING. SOUTH OF WISCONSIN 29...DRY AIR WILL WIN OUT AND IT WILL
ONLY RESULT IN SOME LOWERING OF THE CLOUDS FROM 6 TO 8K FEET TO
AROUND 3K FEET. WHILE THERE WILL BE SOME LIGHT SNOW NORTH OF
WISCONSIN 29...NOT ANTICIPATING ANY ACCUMULATIONS.
LATE TONIGHT AND THURSDAY MORNING...THE LAKE WINNIPEG SHORT WAVE
WILL MOVE QUICKLY SOUTHEAST ACROSS NORTHERN AND EASTERN MINNESOTA
AND NORTHERN WISCONSIN. WITH THE PRIOR SATURATION FROM THE
PREVIOUS SHORT WAVE...THERE WILL SOME LIGHT SNOW ACCUMULATIONS
MAINLY NORTH OF INTERSTATE 94. SNOW ACCUMULATIONS WILL RANGE FROM
A TRACE TO A COUPLE OF TENTHS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM CST WED JAN 27 2016
ON FRIDAY AFTERNOON AND NIGHT...THE MODELS SHOW THAT ANOTHER
SHORT WAVE TROUGH WILL MOVE THROUGH MINNESOTA AND WISCONSIN. DRY
AIR ON THE SOUTHERN PERIPHERY OF THIS SYSTEM MAY LIMIT THE
SOUTHERN EXTENT OF THIS PRECIPITATION...SO KEPT THE HIGHEST
PRECIPITATION CHANCES NORTH OF INTERSTATE 94. SOUNDINGS CONTINUE
TO SHOW THAT THE PRECIPITATION WILL BE MAINLY LIQUID ALONG AND
SOUTH OF INTERSTATE 94. AS A RESULT DEPENDING ON THE SURFACE
TEMPERATURE...THERE MAY BE SOME FREEZING RAIN TO CONTEND WITH.
MEANWHILE NORTH OF INTERSTATE 94...THERE LOOKS TO BE A WINTRY MIX
OF SNOW...FREEZING RAIN...AND SLEET. DUE TO THE MIXED
PRECIPITATION IN THE AREA...WE MAY HAVE TO CONSIDER ISSUING A
WINTER WEATHER ADVISORY.
FROM SATURDAY NIGHT INTO SUNDAY...THE MODELS CONTINUE TO STRUGGLE
WITH A SHORT WAVE MOVING OUT OF THE CENTRAL PLAINS. THERE
CONTINUES TO BE QUESTIONS ON WHETHER THE AIR MASS WILL SATURATE
ENOUGH FOR PRECIPITATION TO OCCUR. IN ADDITION...THERE IS A
QUESTION ON HOW WARM AND DEEP WILL THE WARM LAYER NEAR THE SURFACE
WILL BE. AS A RESULT...JUST WENT WITH RAIN AND SNOW FOR NOW.
FROM TUESDAY INTO WEDNESDAY...THE 27.12Z DETERMINISTIC RUNS ARE IN
GOOD AGREEMENT THAT A CLOSED LOW WILL MOVE THROUGH THE REGION.
THIS LOW BECOMES VERTICALLY STACKED DURING THIS TIME. WHILE THESE
MODELS HAVE FAIRLY DECENT TRACK AGREEMENT WITH LOW MOVING JUST
EAST OF DUBUQUE TO NORTHERN LAKE MICHIGAN. WITH THIS
TRACK...SOUNDINGS SHOW THAT THE TEMPERATURES ALOFT WILL FAVOR
SNOW ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. HOWEVER THE
OPERATIONAL ECMWF WAS JUST FAR ENOUGH WEST THAT THE BOUNDARY LAYER
COULD BE POTENTIALLY WARM ENOUGH FOR A BRIEF PERIOD OF RAIN IN
SOUTHWEST WISCONSIN. AS TYPICAL WITH LOWS MOVING OUT OF THE
SOUTHWEST UNITED STATES...THE MODELS ARE QUITE VARIABLE WITH WHEN
THIS SYSTEM WILL MOVE THROUGH THE REGION. WHILE THERE IS GOOD
AGREEMENT IN THE TRACK OF THE SYSTEM...THE ENSEMBLES SHOW
ADDITIONAL REGIONAL VARIABILITY WITH THE TRACK OF THIS SYSTEM.
A FEW OF THE GFS ENSEMBLE MEMBERS HAVE AN OPEN WAVE AND AS A
RESULT THIS SYSTEM TRACKS WELL TO OUR SOUTHEAST AND THE AREA GETS
LITTLE SNOW FROM THIS SYSTEM. MEANWHILE A FEW OF THE ECMWF MODELS
ACTUALLY HAVE A MORE WOUND UP SYSTEM AND AS A RESULT...THIS
SYSTEM WOULD TRACK WEST OF THE FORECAST AREA AND THE AREA COULD
POTENTIALLY SEE MORE RAIN OR MIXED PRECIPITATION. WITH THIS
SAID...THERE ARE STILL PLENTY OF QUESTIONS WHICH NEED TO BE
ANSWERED WITH THIS SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1133 PM CST WED JAN 27 2016
LOW CLOUDS ARE TEMPORARILY DEPARTING...LEAVING ONLY SOME SCATTERED
TO BROKEN MID LEVEL CLOUDS IN THEIR WAKE FOR A TIME. HOWEVER...AN
APPROACHING SHALLOW COLD FRONT SHOULD BRING BACK MVFR CONDITIONS
LATER TONIGHT INTO MUCH OF THURSDAY...WITH WESTERLY WINDS SHIFTING
NORTHWESTERLY AND BECOMING RATHER GUSTY IN THE 25-30 KNOT RANGE
FROM MID MORNING INTO EARLY AFTERNOON AS LOW LEVEL LAPSE RATES
REALLY STEEPEN. AS MENTIONED PREVIOUSLY...COULD SEE A BRIEF ROUND
OF SNOW SHOWERS RIGHT ALONG AND BEHIND THE INCOMING COLD FRONT...
ESPECIALLY JUST CLIPPING KLSE...BUT CONFIDENCE REMAINS LOW ENOUGH
TO PRECLUDE ANY MENTION EVEN AT THIS TIME. APPROACHING HIGH
PRESSURE AND A WEAKENING GRADIENT WILL ALLOW WINDS TO SLACKEN
QUICKLY TOWARD SUNSET...WITH LOWER STRATUS PERHAPS BEGINNING TO
BREAK UP.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...LAWRENCE
SHORT TERM...AJ/BOYNE
LONG TERM...BOYNE
AVIATION...LAWRENCE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1026 PM CST WED JAN 27 2016
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
AND NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 1006 PM CST WED JAN 27 2016
HAVE INCREASED SNOWFALL ACCUMS TO 1 TO 3 INCHES OVER VILAS COUNTY
TONIGHT...DUE TO A COMBINATION OF SNOW SHOWERS ALONG THE COLD
FRONT AND DEVELOPING LAKE-EFFECT.
CONCERNING THE COLD FRONT...THINK THAT IT MAY BE ACCOMPANIED BY
BRIEF HEAVY SNOW SHOWERS AS IT MOVES THROUGH THE FORECAST AREA
OVERNIGHT INTO EARLY THURSDAY. 850-700 MB LAPSE RATES OF 6 TO 6.5
C/KM WILL BE IN PLACE AHEAD OF THE FRONT...SO THERE IS POTENTIAL
FOR CONVECTIVE ENHANCEMENT. DON`T HAVE MUCH EXPERIENCE USING THE
EXPERIMENTAL SNOW SQUALL PARAMETER...BUT IT IS SHOWING ENHANCED
VALUES OVER NW WI RIGHT NOW. THIS COULD BE A SURPRISE HISA (HIGH
IMPACT SUB-ADVISORY) EVENT FOR THE MORNING COMMUTE IN THE FOX
VALLEY AND LAKESHORE AREAS. WILL ISSUE AN UPDATED SPECIAL WEATHER
STATEMENT TO ADDRESS THIS POSSIBILITY...AND PASS MY CONCERNS TO
THE NIGHT SHIFT.
UPDATE
ISSUED AT 705 PM CST WED JAN 27 2016
BASED ON CURRENT TRENDS...HAVE CONFINED ANY PCPN TO NORTHERN WI
(MAINLY NORTH OF A LINE FROM MERRILL TO STURGEON BAY)THIS EVG.
PCPN TYPE SHOULD BE PRIMARILY LIGHT SNOW AND FREEZING DRIZZLE...
AS MOST SFC TEMPS SHOULD REMAIN AT OR BLO FREEZING IN NORTHERN
WI THROUGH MIDNIGHT. LATER TONIGHT...LIGHT PCPN SHOULD FILL IN
OVER THE REST OF THE FCST AREA AS A COLD FRONT MOVES THROUGH.
MOST OF THIS PCPN SHOULD FALL AS LIGHT SNOW OR FLURRIES.
UPDATE
ISSUED AT 611 PM CST WED JAN 27 2016
INITIAL BAND OF PCPN...WHICH WAS CONFINED TO THE NORTHERN HALF
OF THE FORECAST AREA DUE TO A LACK OF MOISTURE...HAS PULLED OUT
OF NORTHEAST WISCONSIN. NEXT AREA OF PCPN ASSOCIATED WITH THE
COMMA HEAD OF THE SYSTEM WAS MOVG INTO NORTH CENTRAL WI...WITH
NUMEROUS OBSERVATIONS (AND A REPORT FROM VILAS COUNTY) INDICATING
A MIX OF FREEZING DRIZZLE AND LIGHT SNOW OCCURRING THERE. AS THE
DEEP MOISTURE ARRIVES IN FAR NC WI...THE MIXED PXPN SHOULD CHANGE
TO ALL SNOW FOR A WHILE...WITH PERHAPS AN INCH OR SO OF
ACCUMULATION NORTH OF RHINELANDER.
NOT SURE IF PCPN WILL BE CONFINED TO JUST NORTHERN WI FOR THE
REST OF THE NIGHT...AS MODELS SHOW SUBTLE BUT IMPORTANT
DIFFERENCES IN THE MOISTURE PROFILES OVERNIGHT. IF PCPN DOES
DEVELOP FARTHER SOUTH...WARMING SFC TEMPS AND A POSSIBLE
LACK OF ICE IN THE SATURATED LAYER WILL MESS WITH PCPN TYPES.
HAVE RECEIVED A FEW REPORTS OF BLOWING SNOW EARLY THIS EVG...
SO HAVE ADDED PATCHY BLOWING SNOW TO THE FCST. WITH GUSTS
TO 25 TO 35 MPH CONTINUING INTO THE EVG...EXPECT THERE WILL
BE SOME TRAVEL CONCERNS...ESPECIALLY IN OPEN RURAL AREAS...
AND IN THE PORTIONS OF C/EC/NE WI THAT RECEIVED THE HEAVIER
SNOW TOTALS (4-6 INCHES) A COUPLE NIGHTS AGO.
&&
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 314 PM CST WED JAN 27 2016
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A POTENT
CLIPPER MOVING EAST OVER THE BOUNDARY WATERS OF MINNESOTA. A SNOW
BAND IS SLIDING EAST AHEAD OF THE CLIPPER IN A WARM ADVECTION
REGIME. VISIBILITIES WERE FALLING TO A QUARTER AND HALF MILE WITHIN
THE BAND OVER NORTHWEST WISCONSIN EARLY TODAY...INDICATIVE OF HEAVY
SNOW SHOWERS...BUT RADAR EVIDENCE SUGGESTS THAT THE STRONGEST SNOW
SHOWERS HAVE WEAKENED SOME. THIS BAND OF SNOW WILL CONTINUE TO MOVE
TO THE EAST AND IMPACT MOST OF THE REGION NORTH OF ROUTE 29. IT
COULD BRIEFLY DROP VISIBILITIES BELOW A MILE AND ACCUMULATE AROUND A
HALF AN INCH. BEHIND THE BAND OF LIGHT SNOW...SCATTERED FLURRIES AND
DRIZZLE ARE OCCURRING OVER NORTHERN MINNESOTA. AS THE CLIPPER MOVES
ACROSS THE REGION DURING THE NEXT 24 HOURS...PRECIP TRENDS ARE THE
MAIN FORECAST CONCERNS.
TONIGHT...A FAIRLY POTENT YET MOISTURE-STARVED CLIPPER WILL BE
MOVING ACROSS THE REGION...WHILE THE ASSOCIATED SURFACE LOW PASSES
BY OVER LAKE SUPERIOR. BAND OF WARM ADVECTION SNOWS WILL EXIT
NORTHEAST WISCONSIN EARLY THIS EVENING. WILL LIKELY SEE A BRIEF LULL
IN THE PRECIP ACTIVITY BEHIND THIS BAND BASED ON RADAR TRENDS...BUT
THEN RELATIVELY DEEPER MOISTURE WILL PINWHEEL AROUND BACK INTO
NORTHERN WISCONSIN LATER IN THE EVENING AND OVERNIGHT AHEAD OF AN
ARCTIC COLD FRONT. MOISTURE STRUGGLES TO SATURATE AT TIMES ABOVE
-10C...SO LIGHT SNOW OR FLURRIES COULD BE MIXED WITH DRIZZLE AT
TIMES. TEMPERATURES WILL CONTINUE TO SLOWLY RISE DURING THE
EVENING TO NEAR OR ABOVE FREEZING OVER CENTRAL AND NORTHEAST
WI...SO IMPACTS FROM FREEZING DRIZZLE IS REDUCED THERE SOMEWHAT.
COLDER TEMPS ALOFT OVER N-C WI SHOULD SEE THE DOMINANT PRECIP TYPE
AS SNOW...AND ANY FREEZING DRIZZLE WILL LIKELY FALL ON EXISTING
SNOWFALL. SO THINK ANY IMPACTS FROM FREEZING DRIZZLE WILL BE
RELATIVELY MINOR...PERHAPS A FEW SLICK SPOTS COULD DEVELOP ON
UNTREATED ROADS. ADDITIONAL SNOW AMOUNTS COULD REACH AN INCH OR
TWO IN THE SNOW BELTS...WHERE LAKE ENHANCEMENT LATE TONIGHT WILL
PROVIDE MORE PERSISTENT SNOW SHOWER ACTIVITY. OTHERWISE...AMOUNTS
SHOULD REMAIN UNDER AN INCH.
THURSDAY...THE ARCTIC COLD FRONT WILL PUSH ACROSS CENTRAL AND
NORTHEAST WISCONSIN DURING THE MORNING. BREEZY NORTHWEST WINDS
BEHIND THE FRONT WILL USHER IN AN ARCTIC AIRMASS INTO THE
REGION...AND SERVE TO STEEPEN LOW LEVEL LAPSE RATES. COMBINED WITH
CYCLONIC FLOW THROUGH THE COLUMN AND AMPLE LOW LEVEL
MOISTURE...SHOULD SEE AT LEAST SCATTERED SNOW SHOWER AND FLURRY
ACTIVITY. MORE PERSISTENT SNOW SHOWERS WILL AGAIN BE IN THE SNOW
BELT OF N-C WI WHERE AN ADDITIONAL INCH WILL BE POSSIBLE. THINK THE
SNOW SHOWERS WILL GRADUALLY DIMINISH IN THE AFTERNOON AS DRIER AIR
MOVES INTO THE REGION. TEMPS WILL NOT MOVE MUCH WITH THE COLD
ADVECTION OCCURRING. HIGHS IN THE MID 20S NORTH TO MID 30S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 314 PM CST WED JAN 27 2016
NW FLOW INTO THE GREAT LAKES REGION TO DISSIPATE LATE THIS
WEEK...BUT NOT BEFORE ONE MORE WEAK CLIPPER BRUSHES THE AREA FRI
NGT. AS A NEW UPR RDG BUILDS OVER THE ERN PACIFIC THIS WEEKEND...
THE MEAN FLOW BECOMES SPLIT WITH A WEAK NRN STREAM RUNNING ALONG
THE U.S.-CANADIAN BORDER AND A STRONGER SRN STREAM RUNNING FROM
THE SW CONUS ACROSS THE SRN PLAINS. A DEVELOPING SYSTEM IS FCST TO
MOVE INTO THE GREAT LAKES SAT NGT/SUNDAY AND BRING MIXED PCPN TO
NE WI. FOCUS TOWARD THE MIDDLE OF NEXT WEEK CONTS TO BE A STRONG
SYSTEM PROGGED TO LIFT INTO THE MID-MS VALLEY TUE AND THE GREAT
LAKES ON WED. PLENTY OF TIME YET TO DETERMINE PCPN TYPE OR SNOW
TOTALS...BUT DEFINITELY SOMETHING TO WATCH IN THE COMING DAYS.
ANY RESIDUAL LIGHT LAKE EFFECT SNOW SHWRS OR FLURRIES OVER N-CNTRL
WI WL END RATHER QUICKLY THU EVENING AS A RDG OF HI PRES BUILDS
INTO WI. SKIES SHOULD BECOME MOSTLY CLEAR TO PARTLY CLOUDY FOR A
TIME...ALTHO MODELS DO SHOW HI CLOUDS PUSHING INTO WRN WI LATE THU
NGT AHEAD OF THE NEXT CLIPPER. THESE MOSTLY CLEAR/PARTLY CLOUDY
SKIES...COUPLED WITH LIGHT WINDS AND FRESH SNOW WL ALLOW TEMPS TO
EASILY FALL. WL NEED TO CHOP READINGS DOWN A GOOD 3 TO 5 DEGS ON
AVERAGE OVER MOST LOCATIONS WITH NRN WI FROM ZERO TO 5 ABOVE...
CNTRL/E-CNTRL WI AROUND 10 ABOVE AND THE LAKESHORE FROM 10 TO 15.
AS THE SFC RDG SLIDES TO OUR EAST ON FRI...A SOUTHERLY WIND TO
DEVELOP ACROSS WI WITH INCREASING ISEN LIFT AHEAD OF THE CLIPPER
WHICH IS FCST TO REACH NEAR LAKE WINNIPEG BY 00Z SAT. CLOUDS WL
CONT TO THICKEN OVER NE WI THRU THE DAY WITH THE LEADING EDGE OF
PCPN REACHING NRN AND PARTS OF CNTRL WI IN THE MORNING AND THE
REST OF NE WI DURING THE AFTERNOON HOURS. PCPN TYPE SHOULD REMAIN
ALL SNOW...BUT WL HAVE TO WATCH THE LOWER LEVELS OF THE ATMOSPHERE
AS WAA COULD MIX IN A LITTLE SLEET. MAX TEMPS SHOULD BE GENERALLY
IN THE MID TO UPR 20S.L
THE CLIPPER IS FCST TO MOVE EWD INTO WRN ONTARIO FRI NGT AND SWING
A CDFNT ACROSS WI IN THE PROCESS. THE STRONGER MID-LEVEL FORCING
IS PROGGED TO BE FROM NRN WI NWD...THUS HIGHER POPS OVER NRN WI
WHERE UP TO AN INCH OF ACCUMULATION IS POSSIBLE. THE QUICK-MOVING
SPEED OF THIS SYSTEM COUPLED WITH LOW SNOW RATIOS WL LIMIT SNOW
AMOUNTS. ONCE AGAIN...THERE MIGHT BE A LITTLE SLEET OR EVEN
FREEZING RAIN MIXED IN WITH THE SNOW FRI EVENING BEFORE COLDER AIR
ALOFT ARRIVES AND CHANGES PCPN TO ALL SNOW. MIN TEMPS COULD
ACTUALLY SLOWLY RISE UNTIL FROPA AND THEN HOLD SOMEWHAT STEADY TIL
DAYBREAK. LOOK FOR READINGS BY SAT MORNING TO BE INTO THE UPR 20S
NORTH...LWR TO MID 30S SOUTH. THE PCPN IS EXPECTED TO DIMINISH
LATE FRI NGT INTO EARLY SAT MORNING AND COULD END UP AS PATCHY
FREEZING DRIZZLE OR DRIZZLE BEFORE ENDING ALTOGETHER LATE SAT
MORNING. THIS LEAVES THE REGION UNDER A PARTLY TO MOSTLY CLOUDY
SKIE WITH WEST WINDS CONTINUING TO BRING MILD CONDITIONS TO THE
AREA. SAT MAY END UP BEING THE WARMEST DAY OF THE EXTENDED FCST
WITH MAX TEMPS IN THE MID TO UPR 30S NORTH...UPR 30S TO LWR 40S
SOUTH.
MODELS CONT TO SEND A PIECE OF ENERGY FROM THE CNTRL PLAINS TOWARD
THE WRN GREAT LAKES SAT NGT AS THE MEAN FLOW TO BE TURNING TO THE
SW. PCPN TYPE SHOULD INITIALLY BE ALL SNOW...BUT AS WARMER AIR
GETS PULLED NWD INTON WI TOWARD DAYBREAK...WL HAVE TO KEEP AN EYE
ON ANY POTENTIAL FOR A MIX OF EITHER RAIN OR FREEZING RAIN OVER
SRN SECTIONS OF THE FCST AREA. PCPN TYPE WL REMAIN A CONCERN THRU
SUNDAY AS AN AREA OF LOW PRES RIDES NE ALONG AN EWD MOVING CDFNT.
MODELS STILL DISAGREE WITH HOW MUCH WARM AIR WL BE OVER NE WI AS
THE PCPN FALLS...NOT TO MENTION WHERE THE HEAVIEST PCPN WL FALL.
IT APPEARS THAT THE NORTH WOULD REMAIN ALL SNOW THRU THE DAY...
WHILE RAIN WL MIX WITH THE SNOW CNTRL/FAR NE WI AND A MIX WOULD
CHANGE TO ALL RAIN E-CNTRL. AS COLDER AIR BEGINS TO OVERSPREAD WI
LATER IN THE DAY BEHIND THE CDFNT...THE MIXED PCPN OVER CNTRL WI
COULD BEGIN TO SWITCH BACK TO ALL SNOW. MAX TEMPS ON SUNDAY TO
RANGE FROM THE LWR TO MID 30S NORTH...MID TO UPR 30S SOUTH.
CHC OF LIGHT SNOW IS FCST TO LINGER INTO SUNDAY NGT AS THIS SYSTEM
TO BE IN THE PROCESS OF PULLING AWAY FROM WI. A QUIET DAY IS
EXPECTED ON MON AS CAA TO BE IN PLAY UNDER A N-NW WIND. THERE MAY
BE SOME LAKE EFFECT POTENTIAL OVER N-CNTRL WI...BUT ANY ACTIVITY
LOOKS MINOR AT THIS TIME. MAX TEMPS ON MON TO BE A LITTLE COLDER
THAN THE WEEKEND...BUT REMAIN ABOVE NORMAL FOR THE FIRST DAY OF
FEB.
ATTENTION THEN TURNS TO THE POTENTIALLY SIGNIFICANT STORM THAT IS
PROGGED TO LIFT FROM THE SRN PLAINS INTO THE MID-MS VALLEY TUE AND
INTO THE GREAT LAKES REGION TUE NGT/WED. AS IT STANDS RIGHT NOW...
THE TRACK OF THE 8H AND SFC LOW PRES AREAS WOULD FAVOR ALL SNOW
FOR THE ENTIRE FCST AREA. HOWEVER...ANY MINOR JOG TO THE WEST
COULD CREATE PCPN TYPE ISSUES FOR E-CNTRL WI. TUE NGT APPEARS TO
BE THE PERIOD WHERE THE HEAVIEST SNOWS WOULD FALL WITH LIGHT SNOW
CONTINUING THRU WED. TOO EARLY YET TO CONTEMPLATE ACCUMULATIONS...
BUT WITH GUSTY NE...THEN NORTH WINDS EXPECTED...TUE NGT INTO WED
HAVE THE EARMARKS OF A DIFFICULT TRAVELING PERIOD.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1006 PM CST WED JAN 27 2016
LLWS SHOULD TAPER OFF AT THE GRB/ATW/MTW TAF SITES EARLY IN THE
TAF PERIOD.
A MIX OF SNOW...DRIZZLE AND FREEZING DRIZZLE MAY LINGER FOR A FEW
HOURS OVER NORTHERN WI...BUT SHOULD CHANGE TO ALL SNOW AS A COLD
FRONT MOVES THROUGH OVERNIGHT INTO EARLY THURSDAY. BRIEF HEAVY
SNOW SHOWERS MAY ACCOMPANY ALONG THE COLD FRONT AS IT SHIFTS SE
ACROSS THE AREA...SO WILL ATTEMPT TO TIME THESE WITH TEMPO GROUPS
FOR THE TAF SITES. LAKE EFFECT SNOW SHOWERS WILL ALSO INCREASE
OVER FAR NC WI IN THE WAKE OF THE FRONT...AND SHOULD PERSIST
THROUGH MUCH OF THURSDAY. FLIGHT CONDITIONS SHOULD BE MAINLY IN
THE MVFR CATEGORY...THOUGH BRIEF IFR/LIFR CONDITIONS ARE POSSIBLE
WITH SNOW SHOWERS ALONG THE FRONT AND IN VILAS COUNTY (LAKE
EFFECT). ANY LINGERING SNOW SHOULD TAPER OFF ON THURSDAY...WITH
CIGS IN THE 2500-4000 FT AGL RANGE FOR THE LATE MORNING AND
AFTERNOON. PARTIAL CLEARING IS EXPECTED THURSDAY EVG...AS A RIDGE
OF HIGH PRESSURE ARRIVES AND LOW-LEVEL MOISTURE SHALLOWS OUT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......AK
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1048 PM PST FRI JAN 29 2016
...GUSTY NORTHWESTERLY WINDS SUNDAY EVENING AND SUNDAY NIGHT
ESPECIALLY NEAR THE COAST...
...WIDESPREAD RAIN EXPECTED FOR MONTEREY AND SAN BENITO COUNTIES
ON SUNDAY. LOCALLY HEAVY RAIN POSSIBLE BIG SUR COAST AND SANTA
LUCIAS...
.SYNOPSIS...PERIODS OF RAIN WILL CONTINUE OVERNIGHT AS A FRONTAL
BOUNDARY MOVES THROUGH THE AREA FROM NORTH TO SOUTH. GENERALLY
LIGHT AMOUNTS OF RAIN ARE EXPECTED. LITTLE ADDITIONAL RAINFALL IS
EXPECTED SATURDAY AND SATURDAY NIGHT. THE NEXT SYSTEM WILL SPREAD
RAIN ACROSS THE SOUTHERN HALF OF THE FORECAST AREA ON
SUNDAY...WITH LOCALLY HEAVY RAIN POSSIBLE ALONG THE BIG SUR COAST
AND IN THE SANTA LUCIA MOUNTAINS. BEHIND THE SUNDAY
SYSTEM...LOCALLY STRONG AND GUSTY NORTHWEST WINDS ARE EXPECTED
LATE SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...MAINLY NEAR THE
COAST. DRY WEATHER RETURNS MONDAY AND CONTINUES FOR MUCH OF NEXT
WEEK.
&&
.DISCUSSION...AS OF 9:05 PM PST FRIDAY...A MOIST...NEARLY
ZONAL...FLOW CONTINUES ACROSS THE EASTERN PACIFIC AND INTO
NORTHERN CA THIS EVENING. FORCING ALONG THE FRONTAL BOUNDARY HAS
PRIMARILY BEEN DUE TO OROGRAPHIC EFFECTS AND SO RAINFALL OF ANY
SIGNIFICANCE HAS MOSTLY BEEN CONFINED TO THE NORTH BAY
MOUNTAINS...EAST BAY HILLS...AND SANTA CRUZ MOUNTAINS.
WATER VAPOR SATELLITE IMAGERY SHOWS A WEAK SHORTWAVE TROUGH
OFFSHORE...RIPPLING ALONG THE FRONTAL BOUNDARY OUT NEAR 40N/130W.
THIS SHORTWAVE WILL ACT TO PUSH THE FRONTAL BOUNDARY SOUTH
OVERNIGHT AND WE CAN EXPECT RAINFALL TO SPREAD OVER MOST AREAS BY
SUNRISE SATURDAY MORNING. BUT AGAIN...MOST FORCING IS EXPECTED TO
BE FROM OROGRAPHIC EFFECTS. THUS...RAINFALL AT LOWER ELEVATIONS
WILL BE LIGHT...WITH LOCALLY MODERATE AMOUNTS LIKELY ON WEST AND
SOUTHWEST-FACING HILLS THROUGHOUT THE AREA. THE LATEST HRRR MODEL
FORECASTS GENERALLY A TENTH OF AN INCH OR LESS OF RAINFALL AT
LOWER ELEVATIONS TONIGHT...WITH UP TO A HALF INCH IN THE HILLS.
THE MODELS AGREE THAT GENERALLY DRY CONDITIONS WILL PREVAIL
SATURDAY AND SATURDAY NIGHT AS WE WILL BE IN BETWEEN SYSTEMS.
HOWEVER...A RELATIVELY MOIST ONSHORE FLOW WILL PERSIST AND SO RAIN
CHANCES WILL CONTINUE. DURING THIS TIME FRAME RAIN WILL BE MOST
LIKELY IN UPSLOPE AREAS OF THE COASTAL MOUNTAINS.
THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO WHERE THE FOCUS OF
THE NEXT SYSTEM WILL BE. WHAT IS CLEAR IS THAT THAT MOST...IF NOT
ALL...OF THE RAINFALL WITH THE NEXT SYSTEM WILL OCCUR ACROSS THE
SOUTHERN PART OF OUR AREA ON SUNDAY AS A COLD TROUGH MOVING IN
FROM THE NORTHWEST PHASES WITH A SLUG OF MOISTURE MOVING IN FROM
THE WEST. HOWEVER...JUST HOW FAR SOUTH THE FOCUS WILL BE IS STILL
NOT RESOLVED. THE 00Z NAM SPREADS RAIN ACROSS THE SOUTHERN HALF OF
OUR FORECAST AREA ON SUNDAY...WITH LOCALLY HEAVY RAIN PROJECTED
ACROSS MONTEREY AND SAN BENITO COUNTIES THAT DAY...PARTICULARLY
ALONG THE BIG SUR COAST AND IN THE SANTA LUCIAS. HOWEVER...THE 00Z
GFS SHOWS RAINFALL ONLY ACROSS THE SOUTHERN HALF OF MONTEREY AND
SAN BENITO COUNTIES ON SUNDAY...AND ONLY LIGHT TO MODERATE RAIN AT
THAT. THE GFS CONFINES ALL OF THE SIGNIFICANT RAINFALL WITH
SUNDAY`S SYSTEM TO AREAS FORM SLO COUNTY SOUTHWARD. THE 00Z ECMWF
IS NOT YET IN...BUT THE 12Z VERSION OF THAT MODEL CLOSELY
RESEMBLED THE NAM SOLUTION.
RAINFALL WILL END IN MOST AREAS BY LATE SUNDAY AFTERNOON.
BLUSTERY CONDITIONS WILL DEVELOP BY LATE SUNDAY AS A DEEP SURFACE
LOW DEVELOPS NEAR LAS VEGAS AND SURFACE HIGH BUILDS OFFSHORE. THE
GRADIENT BETWEEN THE TWO WILL DRIVE BRISK NORTHWEST WINDS ACROSS
THE REGION FROM LATE SUNDAY THROUGH SUNDAY NIGHT. WINDS WILL
LIKELY PEAK SUNDAY EVENING. STRONGEST WINDS ARE EXPECTED NEAR THE
COAST WHERE LOCAL WIND GUSTS UP TO 50 MPH ARE POSSIBLE. A WIND
ADVISORY MAY BE NEEDED.
COOL CONDITIONS ARE FORECAST EARLY NEXT WEEK. WINDS WILL PROBABLY
PROVIDE ENOUGH MIXING ON SUNDAY NIGHT TO KEEP TEMPS FROM FALLING
TOO MUCH. BUT BY MONDAY NIGHT WE WILL LIKELY SEE TEMPS DROP DOWN
AROUND FREEZING IN THE INLAND VALLEYS.
THE LONGER RANGE MODELS AGREE THAT MOST OF NEXT WEEK WILL BE DRY
WITH PERHAPS JUST A COUPLE OF BRIEF LIGHT RAIN EVENTS.
KMUX RADAR UPDATE: THE KMUX RADAR REMAINS INOPERABLE. A PART
NEEDED TO REPAIR THE RADAR IS ON ORDER AND IS EXPECTED TO ARRIVE
ON SATURDAY. THE EARLIEST THAT THE KMUX RADAR WILL BE RETURNED TO
SERVICE IS SATURDAY AFTERNOON.
&&
.AVIATION...AS OF 10:30 PM PST FRIDAY...FRONTAL SYSTEM MOVING
THE AREA BRINGING LOW CLOUDS WITH AREAS OF REDUCED VISIBILITY AND
LIGHT RAIN. SOME DRIER AIR IN THE LOW AND MID LEVELS WILL ALLOW
FOR RISING CIGS AND EVENTUAL CLEARING SATURDAY MORNING BEHIND THE
FRONT.
VICINITY OF KSFO...MVFR CIGS/VSBYS BUT OCCASIONALLY IFR. LIGHT
RAIN THROUGH 10Z. CONDITIONS IMPROVING AFTER 10Z WITH CIGS RISING
TO AROUND 3000 FEET.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH 18Z. OCCASIONAL CHANCE
FOR PRECIP THROUGH 10Z.
&&
.BEACHES...AS OF 10:50 PM PST FRIDAY...LARGE SWELLS STARTING TO
DECREASE THIS EVENING WITH BUOYS REPORTING HEIGHTS IN THE 11 TO
15 FOOT RANGE WITH PERIOD 16 TO 18 SECONDS. HOWEVER EXCESSIVE
WAVE RUN UP CAN STILL BE EXPECTED WITH THESE WAVES WITH LONG
LULLS BETWEEN WAVE SETS...INCREASING THE RISK OF BEING WASHED OFF
OF THE BEACH OR OFF OF ROCKS BY SNEAKER WAVES. LARGE SURF IS
EXPECTED WITH THESE WAVES AS WELL AS STRONG RIP CURRENTS. SWELLS
WILL CONTINUE TO DECREASE SATURDAY.
&&
.MARINE...AS OF 8:48 PM PST FRIDAY...A WEAK FRONTAL SYSTEM WILL
MOVE THROUGH THE AREA TONIGHT WITH LIGHT TO MODERATE NORTHWEST
WINDS DEVELOPING SATURDAY BEHIND THE SYSTEM. A LOW PRESSURE SYSTEM
WILL MOVE INTO CENTRAL CALIFORNIA SUNDAY BRINGING RAIN TO THE
CENTRAL AND SOUTHERN WATERS. NORTHWEST WINDS WILL INCREASE AFTER
THE LOW MOVES INLAND SUNDAY NIGHT AND MONDAY. A LONG PERIOD SWELL
WILL DECREASE SATURDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY
SOUTH TO MONTEREY COUNTY UNTIL 4 AM
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 4 AM
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: W PI
MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
907 PM PST FRI JAN 29 2016
...GUSTY NORTHWESTERLY WINDS SUNDAY EVENING AND SUNDAY NIGHT
ESPECIALLY NEAR THE COAST...
...WIDESPREAD RAIN EXPECTED FOR MONTEREY AND SAN BENITO COUNTIES
ON SUNDAY. LOCALLY HEAVY RAIN POSSIBLE BIG SUR COAST AND SANTA
LUCIAS...
.SYNOPSIS...PERIODS OF RAIN WILL CONTINUE OVERNIGHT AS A FRONTAL
BOUNDARY MOVES THROUGH THE AREA FROM NORTH TO SOUTH. GENERALLY
LIGHT AMOUNTS OF RAIN ARE EXPECTED. LITTLE ADDITIONAL RAINFALL IS
EXPECTED SATURDAY AND SATURDAY NIGHT. THE NEXT SYSTEM WILL SPREAD
RAIN ACROSS THE SOUTHERN HALF OF THE FORECAST AREA ON
SUNDAY...WITH LOCALLY HEAVY RAIN POSSIBLE ALONG THE BIG SUR COAST
AND IN THE SANTA LUCIA MOUNTAINS. BEHIND THE SUNDAY
SYSTEM...LOCALLY STRONG AND GUSTY NORTHWEST WINDS ARE EXPECTED
LATE SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...MAINLY NEAR THE
COAST. DRY WEATHER RETURNS MONDAY AND CONTINUES FOR MUCH OF NEXT
WEEK.
&&
.DISCUSSION...AS OF 9:05 PM PST FRIDAY...A MOIST...NEARLY
ZONAL...FLOW CONTINUES ACROSS THE EASTERN PACIFIC AND INTO
NORTHERN CA THIS EVENING. FORCING ALONG THE FRONTAL BOUNDARY HAS
PRIMARILY BEEN DUE TO OROGRAPHIC EFFECTS AND SO RAINFALL OF ANY
SIGNIFICANCE HAS MOSTLY BEEN CONFINED TO THE NORTH BAY
MOUNTAINS...EAST BAY HILLS...AND SANTA CRUZ MOUNTAINS.
WATER VAPOR SATELLITE IMAGERY SHOWS A WEAK SHORTWAVE TROUGH
OFFSHORE...RIPPLING ALONG THE FRONTAL BOUNDARY OUT NEAR 40N/130W.
THIS SHORTWAVE WILL ACT TO PUSH THE FRONTAL BOUNDARY SOUTH
OVERNIGHT AND WE CAN EXPECT RAINFALL TO SPREAD OVER MOST AREAS BY
SUNRISE SATURDAY MORNING. BUT AGAIN...MOST FORCING IS EXPECTED TO
BE FROM OROGRAPHIC EFFECTS. THUS...RAINFALL AT LOWER ELEVATIONS
WILL BE LIGHT...WITH LOCALLY MODERATE AMOUNTS LIKELY ON WEST AND
SOUTHWEST-FACING HILLS THROUGHOUT THE AREA. THE LATEST HRRR MODEL
FORECASTS GENERALLY A TENTH OF AN INCH OR LESS OF RAINFALL AT
LOWER ELEVATIONS TONIGHT...WITH UP TO A HALF INCH IN THE HILLS.
THE MODELS AGREE THAT GENERALLY DRY CONDITIONS WILL PREVAIL
SATURDAY AND SATURDAY NIGHT AS WE WILL BE IN BETWEEN SYSTEMS.
HOWEVER...A RELATIVELY MOIST ONSHORE FLOW WILL PERSIST AND SO RAIN
CHANCES WILL CONTINUE. DURING THIS TIME FRAME RAIN WILL BE MOST
LIKELY IN UPSLOPE AREAS OF THE COASTAL MOUNTAINS.
THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO WHERE THE FOCUS OF
THE NEXT SYSTEM WILL BE. WHAT IS CLEAR IS THAT THAT MOST...IF NOT
ALL...OF THE RAINFALL WITH THE NEXT SYSTEM WILL OCCUR ACROSS THE
SOUTHERN PART OF OUR AREA ON SUNDAY AS A COLD TROUGH MOVING IN
FROM THE NORTHWEST PHASES WITH A SLUG OF MOISTURE MOVING IN FROM
THE WEST. HOWEVER...JUST HOW FAR SOUTH THE FOCUS WILL BE IS STILL
NOT RESOLVED. THE 00Z NAM SPREADS RAIN ACROSS THE SOUTHERN HALF OF
OUR FORECAST AREA ON SUNDAY...WITH LOCALLY HEAVY RAIN PROJECTED
ACROSS MONTEREY AND SAN BENITO COUNTIES THAT DAY...PARTICULARLY
ALONG THE BIG SUR COAST AND IN THE SANTA LUCIAS. HOWEVER...THE 00Z
GFS SHOWS RAINFALL ONLY ACROSS THE SOUTHERN HALF OF MONTEREY AND
SAN BENITO COUNTIES ON SUNDAY...AND ONLY LIGHT TO MODERATE RAIN AT
THAT. THE GFS CONFINES ALL OF THE SIGNIFICANT RAINFALL WITH
SUNDAY`S SYSTEM TO AREAS FORM SLO COUNTY SOUTHWARD. THE 00Z ECMWF
IS NOT YET IN...BUT THE 12Z VERSION OF THAT MODEL CLOSELY
RESEMBLED THE NAM SOLUTION.
RAINFALL WILL END IN MOST AREAS BY LATE SUNDAY AFTERNOON.
BLUSTERY CONDITIONS WILL DEVELOP BY LATE SUNDAY AS A DEEP SURFACE
LOW DEVELOPS NEAR LAS VEGAS AND SURFACE HIGH BUILDS OFFSHORE. THE
GRADIENT BETWEEN THE TWO WILL DRIVE BRISK NORTHWEST WINDS ACROSS
THE REGION FROM LATE SUNDAY THROUGH SUNDAY NIGHT. WINDS WILL
LIKELY PEAK SUNDAY EVENING. STRONGEST WINDS ARE EXPECTED NEAR THE
COAST WHERE LOCAL WIND GUSTS UP TO 50 MPH ARE POSSIBLE. A WIND
ADVISORY MAY BE NEEDED.
COOL CONDITIONS ARE FORECAST EARLY NEXT WEEK. WINDS WILL PROBABLY
PROVIDE ENOUGH MIXING ON SUNDAY NIGHT TO KEEP TEMPS FROM FALLING
TOO MUCH. BUT BY MONDAY NIGHT WE WILL LIKELY SEE TEMPS DROP DOWN
AROUND FREEZING IN THE INLAND VALLEYS.
THE LONGER RANGE MODELS AGREE THAT MOST OF NEXT WEEK WILL BE DRY
WITH PERHAPS JUST A COUPLE OF BRIEF LIGHT RAIN EVENTS.
KMUX RADAR UPDATE: THE KMUX RADAR REMAINS INOPERABLE. A PART
NEEDED TO REPAIR THE RADAR IS ON ORDER AND IS EXPECTED TO ARRIVE
ON SATURDAY. THE EARLIEST THAT THE KMUX RADAR WILL BE RETURNED TO
SERVICE IS SATURDAY AFTERNOON.
&&
.AVIATION...AS OF 4:45 PM PST FRIDAY...FRONTAL SYSTEM MOVING
SLOWLY THROUGH. GENERALLY LOW CLOUDS WILL PREVAIL THROUGH
TONIGHT. SOME DRIER AIR IN THE LOW AND MID LEVELS WILL ALLOW FOR
RISING CIGS AND EVENTUAL CLEARING SATURDAY MORNING BEHIND THE
FRONT.
VICINITY OF KSFO...MVFR WITH CIGS AROUND 1500 FEET AND VSBYS 4-6
MILES WITH OCCASIONAL LIGHT RAIN.
SFO BRIDGE APPROACH...SIMILAR TO KSFO WITH CIGS SLIGHTLY HIGHER.
MONTEREY BAY AREA TERMINALS...MVFR CIGS. CHANCE FOR PRECIP WILL
BE BEST AFTER 06Z TONIGHT AS THE FRONT ARRIVES.
&&
.BEACHES...AS OF 4:50 PM PST FRIDAY...LARGE SWELLS CONTINUE OVER
THE COASTAL WATERS WITH BUOYS REPORTING HEIGHTS IN THE 13 TO 16
FOOT RANGE WITH PERIOD 16 TO 19 SECONDS. EXCESSIVE WAVE RUN UP IS
EXPECTED WITH THESE WAVES WITH LONG LULLS BETWEEN WAVE
SETS...INCREASING THE RISK OF BEING WASHED OFF OF THE BEACH OR OFF
OF ROCKS BY SNEAKER WAVES. LARGE SURF IS EXPECTED WITH THESE WAVES
AS WELL AS STRONG RIP CURRENTS. SWELLS WILL DECREASE TONIGHT AND
SATURDAY.
&&
.MARINE...AS OF 8:48 PM PST FRIDAY...A WEAK FRONTAL SYSTEM WILL
MOVE THROUGH THE AREA TONIGHT WITH LIGHT TO MODERATE NORTHWEST
WINDS DEVELOPING SATURDAY BEHIND THE SYSTEM. A LOW PRESSURE SYSTEM
WILL MOVE INTO CENTRAL CALIFORNIA SUNDAY BRINGING RAIN TO THE
CENTRAL AND SOUTHERN WATERS. NORTHWEST WINDS WILL INCREASE AFTER
THE LOW MOVES INLAND SUNDAY NIGHT AND MONDAY. A LONG PERIOD SWELL
WILL DECREASE SATURDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...HIGH SURF ADVISORY...ENTIRE COAST FROM SONOMA COUNTY
SOUTH TO MONTEREY COUNTY UNTIL 4 AM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 9 PM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 9 PM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 9 PM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 9 PM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 9 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 9 PM
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: W PI
MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1254 AM EST SAT JAN 30 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 412 PM EST FRI JAN 29 2016
...WINTRY MIX OF PRECIPITATION TONIGHT...
STRONG SPLIT FLOW PATTERN ALOFT ACROSS THE CONUS TODAY. DECENT JET
IS PRESENT OVER UPPER LAKES IN NW FLOW ALOFT. RIDGING HAS MOVED FM
CNTRL CONUS TO WESTERN GREAT LAKES BUT STRONG SHORTWAVE TROUGH WITH
ASSOCIATED SFC LOW IS OVER CENTRAL MANITOBA. WARM AIR ADVECTION
ALOFT TO THE SOUTH OF THAT SYSTEM WITH H85 TEMPS AT 12Z +10C AT ABR
AND -6C AT INL. SMALLER SHORTWAVE ON SOUTH EDGE OF TROUGH UPSTREAM
OVER DAKOTAS MOVES FM NORTHWEST MN THIS EVENING THEN ACROSS UPR
MICHIGAN AND LK SUPERIOR LATE TONIGHT AND OVER QUEBEC BY MIDDAY
SATURDAY. ASSOCIATED SFC LOW FOLLOWS SUIT...TRACKING ACROSS ONTARIO
AND PUSHING A WARM FRONT OVER UPPER LAKES. PRECIP FORMING OVER MN IS
TIED TO THE SHORTWAVE AND STRONG WARM AIR ADVECTION. EXPECT PRECIP
TO INCREASE AS IT MOVES OVER WESTERN UPR MICHIGAN LATE EVENING AND
OVER REST OF CWA THROUGH THE OVERNIGHT HOURS.
PTYPE WILL BE CONCERN AS RAP/HRRR/NAM SHOW PORTION OF WARM NOSE
ALOFT MAKES IT INTO SW UPR MICHIGAN. MAY BE WARM ENOUGH ALOFT 850-
800MB AOA +3C TO BRIEFLY TURN PRECIP TO FZRA OVER FAR WEST.
ELSEWHERE OVER WEST HALF...SLEET WILL BE POSSIBLE AS WARM LAYER
TEMPS RISE TO +1-2C. HEAVIEST QPF IS PLANNED FOR KEWEENAW. BLEND OF
SHORT TERM HIGH RES GUIDANCE POINTS TO 0.3+ INCHES OVER KEWEENAW
WITH LESSER AMOUNTS OVER REST OF CWA...TAPERING TO LESS THAN 0.10
INCH OVER FAR SOUTH. WITH QPF HIGHEST OVER KEWEENAW AS THAT AREA IS
ALONG TRACK OF SHORTWAVE WENT WITH WINTER WEATHER ADVY FOR SNOW
AMOUNTS MAINLY 2-4 INCHES. IF HRRR OUTPUT IS CORRECT...ISOLD AMOUNTS
AROUND 5 INCHES WOULD NOT BE OUT OF QUESTION MOHAWK TO COPPER
HARBOR. OVER REST OF UPR MICHIGAN...SNOW AMOUNTS WILL BE IN THE 1-3
INCH RANGE. SPS WAS ISSUED TO COVERED SLIPPERY ROADS LATER THIS
EVENING AND OVERNIGHT.
ON SATURDAY...WARM FRONT BLOWS THROUGH IN THE MORNING. MID-LEVEL
MOISTURE IS SCOURED OUT AS THE SHORTWAVE EXITS. ANY PRECIP EARLY
ON WILL BE IN THE FORM OF FZDZ. UPSLOPE WEST WINDS MAY KEEP LOW
CLOUDS AND SOME DZ OVER KEWEENAW INTO THE MIDDAY HOURS...BUT
ELSEWHERE LOW CLOUDS SHOULD GRADUALLY DECREASE. TEMPS ALOFT...JUST
ALOFT AT 925-900MB ARE PRETTY WARM ON THE POSITIVE SIDE OF 0C. MIXING
TO 925MB SUPPORTS MAX TEMPS INTO LOW 40S FOR DOWNSLOPE AREAS. IF WE
CAN MIX TO 900MB...AROUND 3KFT...TEMPS MAY JUMP EVEN HIGHER. WILL ALL
DEPEND ON EXTENT OF SUNSHINE/MIXING. COULD BE BREEZY ON KEWEENAW WITH
WSW WINDS UP TO 20 MPH AND SOME HIGHER GUSTS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 417 PM EST FRI JAN 29 2016
BEGINNING SAT NIGHT...A SHORTWAVE MOVING IN FROM THE NORTHERN PLAINS
WILL PUSH A SFC TROUGH INTO THE AREA. FORCING ASSOC WITH THE
SHORTWAVE COULD SUPPORT SOME LIGHT SNOW ACROSS THE CWA LATE EVENING
INTO OVERNIGHT...AND POSSIBLY A MIX OF SNOW...RAIN OR FREEZING RAIN
OVER SOUTH CENTRAL COUNTIES.
SUN/SUN NIGHT...THE GFS AND NAM ARE SHOWING MORE INTERACTION BETWEEN
A COUPLE OF SHORTWAVES TRACKING ACROSS THE CONUS...RESULTING IN A
DEEPER WAVE TAKING ON A NEGATIVE TILT AS IT SHIFTS ACROSS THE WRN
GREAT LAKES REGION. TO VARYING DEGREES...THE GFS HAS GENERALLY
INDICATED SUCH A SCENARIO FOR SEVERAL RUNS...AND NOW THE NAM HAS
JOINED SUIT THE LAST FEW RUNS. THE GFS IS A BIT QUICKER THAN THE NAM
BRINGING MODERATE TO HEAVY SNOW INTO THE AREA ALREADY ON SUN WHILE
THE NAM INDICATES A POTENTIAL FOR MODERATE TO HEAVY SNOW MAINLY SUN
NIGHT. BOTH MODELS WOULD SUPPORT A HEADLINE EVENT FOR MODERATE TO
HEAVY SNOWFALL AFFECTING MUCH OF THE CWA DURING THE PERIOD.
THE 12Z CANADIAN HAS NOW ALSO TRENDED DEEPER AND FARTHER NORTH WITH
SHORTWAVE AND ASSOC SFC LOW PER NAM AND GFS BUT THE 12Z ECMWF
REMAINS WEAKER AND FARTHER SOUTH ONLY ADDING TO FCST UNCERTAINTY. WL
LIKELY NEED TO BUMP POPS UP A BIT TO REFLECT MODEL CONSENSUS TRENDS
OF STRONGER SYSTEM TRACKING FARTHER NORTH...BUT THIS SYSTEM WILL
DEFINITELY BE ONE TO WATCH OVER THE NEXT FEW MODEL RUNS. IF MODELS
BEGIN TO CONVERGE ON DEEPER AND FARTHER NORTH SOLUTION...WILL LIKELY
NEED WSW HEADLINES FOR A GOOD PORTION OF THE FCST AREA.
MON/MON NIGHT...AFTER ANY LINGERING PCPN ENDS FOLLOWING THE PASSAGE
OF THE SHORTWAVE TO THE E...NW FLOW LOWERING 850MB TEMPS DOWN TO -12
TO -16C FOR AT LEAST A TIME WILL GENERATE SOME LIGHT LES UNDER A LOW
INVERSION.
TUE-WED...GFS/ECMWF/CANADIAN MODELS STILL SHOWING MEANINGFUL
DIFFERENCES REGARDING TRACK OF A POTENTIAL SIGNIFICANT WINTER STORM
TO AFFECT THE GREAT LAKES REGION LATER TUE/WED NEXT WEEK. A NUMBER
OF GFS ENSEMBLES AND CANADIAN ENSEMBLES INCLUDING THE 12Z
OPERATIONAL GFS ARE SUPPORTIVE OF A STRONGER AND FARTHER NORTH SFC
LOW TRACK THROUGH CENTRAL TO NORTHERN LOWER MI WHICH WOULD RESULT IN
MODERATE TO POSSIBLY HEAVY SNOW FOR PROBABLY AT LEAST THE CENTRAL
AND ERN COUNTIES OF UPPER MI. ON THE OTHER HAND...THE 00/12Z
OPERATIONAL ECMWF/CANADIAN/UKMET ARE TRENDING FARTHER SOUTH AND
WEAKER WITH STORM SYSTEM...TRACKING IT THROUGH FAR SRN LOWER MI AND
ACROSS FAR SOUTHERN LAKE HURON WHICH WOULD KEEP MUCH OF THE SYSTEM
SNOW FARTHER SOUTH OF UPPER MI. THE MODEL UNCERTAINTY DEFINITELY
ARGUES FOR TAKING A CONSERVATIVE APPROACH WHEN DETERMINING THE
POSSIBLE IMPACT OF THIS WINTER STORM FOR UPPER MI. IF THE OPERATIONAL
GFS AND THE MAJORITY OF THE GFS ENSEMBLE RUNS PAN OUT MUCH OF THE
CENTRAL AND EASTERN CWA WILL LIKELY SEE AT LEAST ADVISORY TO POSSIBLE
WARNING LEVEL SNOW AMOUNTS. FAIRLY FAST MOVEMENT OF STORM SYSTEM WILL
WORK TO KEEP SYSTEM FROM PRODUCING WIDESPREAD VERY HEAVY SNOW TOTALS.
IN ADDITION...UPSLOPING/POSSIBLE LAKE ENHANCEMENT (850MB TEMPS FALL
FROM -10 TO -15C DURING THE ENHANCEMENT PHASE OFF THE LAKE) COULD ADD
TO SNOW TOTALS OVER NCNTRL UPPER MI. THIS WILL LIKELY BE CASE EVEN IF
THE WEAKER AND FARTHER SOUTH MODEL SOLUTION OF NON NCEP MODELS PAN
OUT.
THU-FRI...MODELS TREND TOWARD GENERALLY A DRIER AND COOLER PERIOD
FOR LATE NEXT WEEK WITH SOME LINGERING LAKE EFFECT IN WESTERLY WIND
SNOW BELTS OF LAKE SUPERIOR. MODELS HINT AT A WEAK SHORTWAVE MOVING
THROUGH THE AREA WHICH MAY PRODUCE A PERIOD OF LIGHT SNOW/FLURRIES
BUT AT THIS TIME IT DOES NOT LOOK LIKE ANYTHING MORE THAN A DUSTING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1236 AM EST SAT JAN 30 2016
AS A SFC LOW MOVES TO NW ONTARIO OVERNIGHT PERIODS OF SNOW WILL
CONTINUE OVER WEST AND CENTRAL UPPER MICHIGAN. IFR CONDITIONS AT CMX
AND IWD ARE EXPECTED DUE TO VSBY. LATE TONIGHT INTO EARLY SAT AS THE
STEADY SNOW TAPERS SOME FZDZ IS POSSIBLE. THIS IS ALSO WHEN CIGS
WILL HAVE BEST CHANCE TO FALL BLO 010. ONCE THE WARM FRONT
MOVES THROUGH...EXPECT SKIES TO CLEAR OUT AND GUSTY SW-W WINDS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 PM EST FRI JAN 29 2016
STRONG LOW TRACKING OVER NORTHERN ONTARIO LATE TONIGHT INTO SATURDAY
MORNING WILL RESULT IN SOUTH WINDS 20-30 KTS...WITH GALES TO 35 KTS
OVER EAST HALF. GALE WARNING WAS ISSUED. WINDS DIMINISH SAT NIGHT
INTO SUN AS RIDGING MOVES OVERHEAD. A COUPLE OF LOW PRESSURE SYSTEMS
TRACKING ACROSS THE CENTRAL GREAT LAKES MAY BRING NORTH TO NORTHEAST
GALES SUN NIGHT INTO MON AND AGAIN TUE NIGHT INTO WED. AT THIS TIME
BEST CHANCE FOR WIDESPREAD GALES WOULD BE TUE NIGHT INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MIZ001-
003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS DULUTH MN
320 AM CST SAT JAN 30 2016
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 320 AM CST SAT JAN 30 2016
TODAY...THE NORTHLAND CAN EXPECT A ZONAL FLOW PATTERN...WHICH WILL
BRING RELATIVELY WARM AIR MODIFIED BY THE ROCKY MOUNTAINS. A LOW
OVER EASTERN CENTRAL MANITOBA WILL MOVE EAST ACROSS NORTHERN
ONTARIO. LOW LEVEL CLOUDS ASSOCIATED WITH THE LOW COULD AFFECT THE
FAR NORTHERN FORECAST AREA...OTHERWISE MOST OF THE NORTHLAND
SHOULD ONLY BE AFFECTED BY CIRRUS AS A 110 KNOT UPPER LEVEL JET
MOVES INTO THE SOUTHERN FORECAST FROM THE WEST. THE UPPER LEVEL
CLOUD COVER SHOULD BE RELATIVELY THIN UNTIL THE LATE
AFTERNOON...SO SOME SUNSHINE WILL MAKE IT THROUGH TO HELP WARM UP
THE NORTHLAND. TEMPERATURES WILL ALREADY BE STARTING RELATIVELY IN
THE MIDDLE TO UPPER 20S EARLY THIS MORNING...SO IT SHOULD NOT BE
DIFFICULT TO REACH THE MIDDLE TO UPPER 30S. HOPING THERE IS ENOUGH
SUNSHINE TO HELP MELT MY ICY DRIVEWAY!
TONIGHT...A TROUGH WILL MOVE THROUGH THE UPPER MIDWEST. MOST OF
THE MODELS ARE INDICATING THERE COULD BE LIGHT PCPN NEAR AND IN
THE WAKE OF THE LOW LEVEL TROUGH...BUT MOST MODELS KEEP THIS PCPN
SOUTH AND EAST OF THE FORECAST AREA. THE EXCEPTION IS THE
CANADIAN...BUT SINCE IT IS SUCH AN OUTLIER FROM THE OTHER
MODELS...LEANED ON THE MAJORITY OF THE MODELS. THEREFORE...LOWERED
PCPN CHANCES FROM THE PREVIOUS FORECAST...AND LIMITED THE CHANCES
OF PCPN TO THE FAR SE FORECAST AREA. IF THE PCPN OCCURS...THERE
COULD BE A WINTRY MIXTURE OF FREEZING RAIN AND SNOW. THE UPPER
LEVEL TROUGH WILL BE OVER THE NORTHLAND...WHICH WILL HELP KEEP THE
NORTHLAND PRIMARILY CLOUDY. THE CLOUD COVER SHOULD HELP
BOLSTER TEMPERATURES...SO WEIGHTED THE FORECAST TO THE SLIGHTLY
WARMER ECMWF AND NAM12. LOWS SHOULD BE IN THE LOW TO MIDDLE 20S.
SUNDAY...THE UPPER LEVEL TROUGH WILL CONTINUE MOVING THROUGH THE
NORTHLAND...AND WNW FLOW WILL BRING COOLER AIR INTO THE REGION.
THERE COULD BE LINGERING LIGHT PCPN ACROSS THE FAR SE FORECAST
AREA. THE PCPN COULD BE A WINTRY MIXTURE OF FREEZING RAIN OR SNOW
IN THE MORNING...THEN TRANSITION TO RAIN AND SNOW IN THE AFTERNOON
WITH THE WARMING TEMPERATURES. HIGHS SHOULD RANGE FROM THE UPPER
20S AND LOW 30S ACROSS NE MINNESOTA...TO THE LOWER 30S ACROSS NW
WISCONSIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 AM CST SAT JAN 30 2016
A SHORT WAVE TROF CROSSES THE FORECAST AREA SUNDAY EVENING.
BEHIND THE TROF...A FAST NW FLOW ALOFT COVERS THE AREA. MODELS
BRING A PIECE OF ENERGY THROUGH NORTHERN MN OVERNIGHT.
MEANWHILE...A SFC TROF WAS NEARBY. DEEPEST MOISTURE IS LOCATED
OVER NORTHERN MN AND HAVE SMALL POPS AS A RESULT. MODEL
DIFFERENCES WITH THE SFC TROF AND OVERALL COVERAGE OF QPF LED TO
SMALL POPS AROUND THE PERIPHERY OF LAKE SUPERIOR AND INTO NW WI
LATE. WITH LIGHT QPF AMOUNTS...SNOW AMOUNTS WILL ALSO BE LIGHT.
ADDITIONAL PIECES OF ENERGY WILL ZIP THROUGH THE REGION ON MONDAY.
HOWEVER...BEST OPPORTUNITY FOR LIGHT SNOW WILL BE RESTRICTED TO
THE SOUTH SHORE OF LAKE SUPERIOR INTO NORTH CENTRAL WI WHERE THE
SFC TROF LINGERS BEFORE DISSOLVING IN THE AFTERNOON. A BRIEF BREAK
ARRIVES MONDAY NIGHT WITH SFC RIDGING OVER THE REGION. MODELS HAVE
COME IN A BIT FARTHER NORTH THAN THE PREVIOUS RUNS FOR TUESDAY AND
TUESDAY NIGHT. USED A BLEND OF THE GFS/ECMWF/PREVIOUS FORECAST FOR
POPS TUESDAY AND TUESDAY NIGHT. THE SNOW WILL BE RESTRICTED TO NW
WI TUESDAY MORNING AS BOTH MODELS PLACE MINOR QPF IN THIS AREA.
THE SNOW SHOULD BEGIN TO RAMP UP TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT. DIFFERENCES BECOME QUITE LARGE IN THE SPEED OF THE SYSTEM
TUESDAY NIGHT...PLACEMENT OF QPF/AMOUNTS. THE GFS IS FASTER AT
MOVING OFF THE HIGHER QPF AMOUNTS WHILE THE ECMWF HANGS A GENEROUS
AMOUNT BACK OVER NW WI AND THROUGH THE TWIN PORTS AND UP THE NORTH
SHORE. THIS PLAYS A HUGE ROLE IN THE SNOW AMOUNTS TUESDAY NIGHT.
WILL HOLD OFF ON ANY HEADLINES UNTIL THE SYSTEM GETS CLOSER AND
THE MODEL DIFFERENCES IMPROVE. THE GFS MAINTAINS ITS QUICKNESS ON
WEDNESDAY WITH THE DEPARTURE OF THIS SYSTEM WHILE THE ECMWF IS
SLOWER. THE ECMWF ALSO DEVELOPS A SFC LOW IN ND WEDNESDAY
AFTERNOON WHILE THE GFS DOES NOT. WILL MAINTAIN THE PREVIOUS
FORECAST OF LOW POPS OVER NW WI AS A RESULT. MODEL DIFFERENCES
BECOME QUITE LARGE AGAIN WEDNESDAY NIGHT. THE ECMWF BRINGS THE ND
SFC LOW INTO MN ALONG WITH A DEEPENING SHORTWAVE TROF. THE GFS HAS
A BROADER LONGWAVE TROF MOVING OVER THE AREA WITH SFC RIDGING.
LEANED ON A BLEND OF THE PREVIOUS FORECAST AND THE GFS AND HAVE NO
POPS. THE AFOREMENTIONED DIFFERENCES PERSIST ON THURSDAY WITH THE
ECMWF SLOWLY DEPARTING ITS SYSTEM...WHILE THE GFS HAS PIECES OF
ENERGY MOVING THROUGH THE LONG WAVE TROF OVER THE AREA. A BLEND
RESULTS IN LOW POPS. THE DISCREPANCIES CONTINUE THURSDAY NIGHT AND
FRIDAY AND HAVE BLENDED POPS AS A RESULT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1116 PM CST FRI JAN 29 2016
A TROUGH OF LOW PRESSURE AND SHORTWAVE WERE CONTINUING TO MOVE
THROUGH THE NORTHLAND LATE THIS EVENING WITH THE BACK EDGE OF THE
HEAVIER PRECIPITATION STRETCHING FROM THE ARROWHEAD TO NEAR KHYR.
THIS WILL CONTINUE TO MOVE EAST CLEARING THE NORTHLAND BETWEEN
07-08Z...LEAVING BEHIND FLURRIES OR PATCHY FREEZING DRIZZLE.
CLEARING WAS ALREADY MADE IT TO KINL/KBRD AND WILL PROGRESS EAST
OVERNIGHT. THE RAP DOES BRING SOME LOW VFR/MVFR CEILINGS BACK
ALONG THE INTERNATIONAL BORDER LATER TONIGHT...LASTING THROUGH THE
REST OF THE PERIOD.
WINDS WILL BE WEST TO SOUTHWEST TONIGHT...GUSTY AT TIMES...THEN
TURN NORTHWEST OVER NORTHERN MINNESOTA SATURDAY EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 37 23 31 19 / 0 0 10 20
INL 35 23 28 12 / 0 10 10 20
BRD 38 22 32 20 / 0 0 10 10
HYR 38 25 34 21 / 0 10 10 20
ASX 39 25 34 21 / 0 10 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...GSF
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1116 PM CST FRI JAN 29 2016
.UPDATE...
ISSUED AT 1116 PM CST FRI JAN 29 2016
THE PRECIPITATION WAS DIMINISHING FROM WEST TO EAST LATE THIS
EVENING...SIMILAR TO WHAT THE NAM/RAP HAVE BEEN SHOWING. THE
ADVISORY FOR THE ARROWHEAD AND A PORTION OF NORTHWEST WISCONSIN
REMAINS IN EFFECT THROUGH MIDNIGHT AND WE WILL LIKELY LET THAT
EXPIRE THEN. LIGHT TO MODERATE SNOW WILL CONTINUE THROUGH 7Z...BUT
THEN SHOULD TRANSITION TO FLURRIES OR PATCHY FREEZING DRIZZLE.
FURTHER WEST...WE EXPECT SOME FLURRIES/PATCHY FREEZING DRIZZLE FOR
ANOTHER HOUR OR SO IN FAR EASTERN MINNESOTA...THEN CLEARING LATE.
UPDATE ISSUED AT 600 PM CST FRI JAN 29 2016
STRONG WAA WAS OCCURRING WITH THE LLJ EARLY THIS EVENING ALONG
WITH A SHORTWAVE DIVING INTO MINNESOTA PER LATEST WATER VAPOR
IMAGERY. THESE FEATURES WERE PRODUCING GOOD LIFT FOR A WINTRY MIX
OF SLEET...FREEZING RAIN AND SNOW ACROSS MUCH OF THE NORTHLAND
THIS EVENING. WE ISSUED A WINTER WEATHER ADVISORY FOR MUCH OF THE
AREA THIS EVENING. MN DOT REPORTING MANY ROADS ACROSS NORTHEAST
MINNESOTA WERE ICE COVERED OR PARTIALLY ICE COVERED AND WE EXPECT
THAT TO OCCUR ACROSS PORTIONS OF NORTHWEST WISCONSIN AS WELL.
THE NAM AND SEVERAL OF THE HIGH RES MODELS WERE DEPICTING THE
PRECIP COVERAGE FAIRLY WELL...AND THEY HAVE THE BULK OF THE PRECIP
MOVING OFF AROUND MIDNIGHT...LINGERING A BIT LONGER OVER THE TIP
OF THE ARROWHEAD AND OVER OUR FAR EASTERN WISCONSIN ZONES.
HOWEVER...THEY MODELS DO SEEM TO BE UNDERDOING THE AMOUNT OF WARM
AIR ALOFT AND WE ADJUSTED THE GRIDS FOR MORE FREEZING RAIN THROUGH
THE EARLY EVENING HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 310 PM CST FRI JAN 29 2016
A 40-50 KNOT LOW LEVEL JET WILL CONTINUE TO USHER INCREASING
MOISTURE AND WARMING MID LEVEL TEMPERATURES INTO THE WESTERN LAKE
SUPERIOR REGION THIS EVENING. LATEST RUC ANALYSIS SHOWS AN AREA OF
INCREASING RADAR RETURNS IS CO-LOCATED WITH A CORRIDOR OF MAX
850PHA TEMPS AND PWATS EXCEEDING A HALF INCH OVER NORTHWEST
MINNESOTA. THE AREA OF FORCING AHEAD OF THE UPPER LEVEL
TROUGH/VORT MAX AND PRECIPITATION WILL SPREAD EAST OVER THE
NORTHLAND THROUGH THE NIGHT.
SHORT TERM FOCUS ON PRECIPITATION TYPE AND LIGHT ICE
ACCUMULATIONS OVERNIGHT. ANTICIPATING SURFACE TEMPERATURES TO RISE
A FEW DEGREES THROUGH THE EVENING...DUE TO THE STRONG WARM AIR
ADVECTION. HOWEVER...THERE IS UNCERTAINTY IF TEMPERATURES WILL
WARM ENOUGH TO SUPPORT ALL RAIN FOR MOST AREAS...OR WILL REMAIN MIX
WITH SLEET/FREEZING RAIN FOR THE EVENING. LATEST NAMBUF SOUNDINGS
SHOW PROFILES SUGGEST A FEW HOUR PERIOD OF A WINTRY MIX LATE
TODAY...BEFORE DEEPLY SATURATING AND SUPPORTING ALL SNOW AFTER
1000PM-MIDNIGHT BEHIND THE FRONTAL PASSAGE. AT THIS TIME THE MAIN
THREAT FOR LIGHT ICE ACCUMULATIONS IS FROM THE TWIN PORTS...SOUTH
ALONG THE INTERSTATE 35 CORRIDOR...AND EAST ACROSS NORTHERN
WISCONSIN. PRIMARILY SNOW...WITH LIGHT ACCUMULATIONS OF AN INCH
OR TWO CAN BE EXPECTED IN THE MINNESOTA ARROWHEAD ZONES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 310 PM CST FRI JAN 29 2016
.LONG TERM...
THE LONG TERM PERIOD IS SHAPING UP TO BE QUITE ACTIVE ACROSS THE
NORTHLAND...WITH A COUPLE MAJOR WEATHER SYSTEMS AFFECTING THE REGION
THROUGHOUT THE PERIOD. ON SATURDAY NIGHT...THE FIRST SYSTEM WILL
MOVE INTO THE CENTRAL PLAINS. THE NAM AND GFS ARE IN THE BEST
AGREEMENT...BRINGING THE SURFACE LOW TO JUST SOUTH OF GREEN BAY BY
00Z MONDAY ON BOTH MODELS. THE ECMWF IS DEFINITELY THE OUTLIER WITH
THIS SYSTEM. HAVE INCREASED POPS ACROSS THE SE 1/2 TO 2/3 OF THE
CWA...ALTHOUGH THE BEST CHANCE OF SEEING A WINTRY MIX FOLLOWED BY
SNOW SATURDAY NIGHT AND SUNDAY. COULD SEE SOME SNOW ACCUMULATION
DURING THAT PERIOD...WITH LESS THAN AN INCH IN NE MN...AND 1 TO 3
INCHES IN NW WI. THE FOCUS WILL SHIFT TO THE SOUTH SHORE OF LAKE
SUPERIOR MONDAY AND MONDAY NIGHT...AS HIGH PRESSURE BUILDS IN AND
WINDS BECOME MORE NORTHERLY. THE BIG STORY FOR THE EXTENDED TIME
PERIOD WILL BE THE POTENTIAL FOR LOCALLY HEAVY SNOW AND INTENSE
WINDS ON TUESDAY AND TUESDAY NIGHT. THE MODELS ARE IN BETTER
CONSENSUS REGARDING THIS SYSTEM...WITH THE GREATEST POTENTIAL FOR
SNOW ACCUMULATION ACROSS OUR NW WI AREA. THE ECMWF BRINGS THE LEAST
SNOW TO NW WI...WHILE THE GFS BRINGS THE MOST. WILL CONTINUE TO HIT
NW WI HARDEST...ALTHOUGH IT DOES APPEAR THAT THE HEAVIEST SNOW WILL
BE EVEN A BIT SOUTH OF OUR CWA. STILL A BIT TOO EARLY TO TELL FOR
SURE...BUT A MAJOR WINTER STORM HAS THE POTENTIAL TO COME CLOSE TO
OUR CWA...IF NOT INTO A PORTION OF OUR CWA. SEVERAL INCHES OF SNOW
WILL BE POSSIBLE ACROSS MUCH OF WISCONSIN. GENERALLY SMALL CHANCES
OF SNOW WILL BE POSSIBLE DURING THE LATTER PART OF THE UPCOMING WORK
WEEK. HIGH TEMPERATURES WILL RANGE FROM THE 30S FOR MOST AREAS ON
SUNDAY...TO THE TEENS AND 20S FOR THE REST OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1116 PM CST FRI JAN 29 2016
A TROUGH OF LOW PRESSURE AND SHORTWAVE WERE CONTINUING TO MOVE
THROUGH THE NORTHLAND LATE THIS EVENING WITH THE BACK EDGE OF THE
HEAVIER PRECIPITATION STRETCHING FROM THE ARROWHEAD TO NEAR KHYR.
THIS WILL CONTINUE TO MOVE EAST CLEARING THE NORTHLAND BETWEEN
07-08Z...LEAVING BEHIND FLURRIES OR PATCHY FREEZING DRIZZLE.
CLEARING WAS ALREADY MADE IT TO KINL/KBRD AND WILL PROGRESS EAST
OVERNIGHT. THE RAP DOES BRING SOME LOW VFR/MVFR CEILINGS BACK
ALONG THE INTERNATIONAL BORDER LATER TONIGHT...LASTING THROUGH THE
REST OF THE PERIOD.
WINDS WILL BE WEST TO SOUTHWEST TONIGHT...GUSTY AT TIMES...THEN
TURN NORTHWEST OVER NORTHERN MINNESOTA SATURDAY EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 27 38 25 32 / 100 10 20 20
INL 30 35 22 26 / 70 10 0 10
BRD 28 38 25 31 / 70 10 10 20
HYR 24 40 28 34 / 100 10 40 50
ASX 24 43 28 34 / 100 10 30 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
WIZ002>004-008-009.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ012-
020-021.
LS...NONE.
&&
$$
UPDATE...MELDE
SHORT TERM...GRANING
LONG TERM...DAP
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS Tulsa OK
1111 PM CST FRI JAN 29 2016
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
VFR conditions will prevail through the forecast period for all sites.
&&
.PREV DISCUSSION... /ISSUED 930 PM CST FRI JAN 29 2016/
DISCUSSION...
A weak surface boundary will move into the area tonight shifting
the winds to the northwest across parts of eastern Oklahoma. This
boundary will wash out by midday Saturday with south winds
returning to all areas. Temperatures today greatly exceeded
expectations and model low level thermal progs and the latest
experimental HRRR data suggests Saturday will only be a few
degrees cooler than today in northeast Oklahoma, and as warm as
today across southeast Oklahoma and northwest Arkansas. Thus, have
raised high temperatures Saturday by at least 5 degrees
everywhere, and there is a chance this may not be quite warm
enough. Have also made minor adjustments to the overnight low
tonight at KBVO. The rest of the forecast looks good at this
time.
Update on the way.
TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
$$
SHORT TERM...07
LONG TERM....05
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 39 70 51 59 / 0 0 0 0
FSM 42 74 51 66 / 0 0 0 0
MLC 42 72 52 63 / 0 0 0 0
BVO 33 65 46 58 / 0 0 0 0
FYV 41 69 49 60 / 0 0 0 10
BYV 41 68 48 63 / 0 0 0 10
MKO 40 68 50 62 / 0 0 0 0
MIO 39 67 49 59 / 0 0 0 10
F10 40 69 51 61 / 0 0 0 0
HHW 43 71 52 67 / 0 0 10 10
&&
.TSA Watches/Warnings/Advisories...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...07
AREA FORECAST DISCUSSION
NWS MEDFORD OR
817 PM PST FRI JAN 29 2016
.UPDATED AVIATION DISCUSSION.
.DISCUSSION...A COLD FRONT HAS SWEPT THROUGH THE FORECAST AREA...AND
THE RELATIVELY WARM PATTERN WITH HIGH SNOW LEVELS HAS ENDED. SNOW
LEVELS ARE NOW ABOUT 3500 FEET AND WILL CONTINUE TO FALL
OVERNIGHT. FAVORABLE JET DYNAMICS IS ENHANCING PRECIPITATION OVER
NORTHEAST CALIFORNIA...AND WE HAVE ISSUED A WINTER WEATHER
ADVISORY AT WSWMFR FOR SEVERAL INCHES OF SNOW EXPECTED THIS
EVENING IN LOCATIONS SUCH AS ALTURAS. THE HRRR SHOWED THIS ENHANCED
AREA OF PCPN THE BEST...AND IT SHOWS SNOW DIMINISHING THERE BY
MIDNIGHT. ELSEWHERE...SNOW IS EXPECTED TO IMPACT THE FOOTHILLS OF
THE CASCADES TONIGHT IN JACKSON AND DOUGLAS COUNTIES AND THE WSW
CONTINUES FOR THOSE AREAS INTO SATURDAY MORNING.
WESTERLY FLOW ALOFT WILL HELP BRING 3-6 MORE INCHES OF SNOW TO THE
CASCADES TONIGHT INTO TOMORROW. TRAVELERS INTO THE MOUNTAINS CAN
EXPECT SOME SNOW COVERED ROADS AND LOWER VISIBILITIES THROUGH
SATURDAY.
SATURDAY WILL FEATURE THE AFOREMENTIONED RAIN AND SNOW
SHOWERS...WITH SNOW LEVELS DIPPING TO ABOUT 2000 FEET. NAM12 OUTPUT
SUGGESTS ENOUGH INSTABILITY FOR THUNDERSTORMS FOR MUCH OF THE WEST
SIDE...GENERALLY ALONG AND WEST OF I-5.
SEE THE PREVIOUS DISCUSSION BELOW FOR MORE DETAILS ON THE SHOWERY
AND COLD CONDITIONS EXPECTED THIS WEEKEND.
&&
.AVIATION...FOR THE 30/06Z TAF CYCLE...MVFR/IFR AND NEAR TOTAL
TERRAIN OBSCURATION IN SHOWERS IS EXPECTED THROUGH THE NIGHT. THE
WORST CONDITIONS WILL LIKELY BE IN THE CASCADES AND IN MODOC COUNTY
WHERE SNOW SHOWERS WILL BRING IFR VISIBILITIES. ANOTHER WEAK
DISTURBANCE WILL BRING A MORE FOCUSED PERIOD OF SHOWERS TO THE COAST
AROUND MIDNIGHT WITH CIGS POTENTIALLY LOWERING TO MVFR AT TIMES.
SCATTERED TO WIDESPREAD SHOWERS ARE EXPECTED ON SATURDAY...MAINLY
FROM THE CASCADES WEST. ADDITIONALLY...THUNDERSTORMS ARE POSSIBLE
OVERNIGHT INTO TOMORROW OVER THE COASTAL WATERS TO AREAS JUST
INLAND. FB/SK
&&
.MARINE...UPDATED 800 PM PST FRI 29 JAN 2016...STEEP SEAS AND WEST
SWELL WILL GRADUALLY SUBSIDE OVER THE WEEKEND BUT WILL REMAIN
HAZARDOUS TO SMALL CRAFT UNTIL EARLY NEXT WEEK. HIGH PRESSURE WILL
BUILD INTO THE WATERS LATE THIS WEEKEND. WEAK LOW PRESSURE WILL
ARRIVE TUESDAY MORNING BUT WINDS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. SK
&&
.PREV DISCUSSION... /ISSUED 235 PM PST FRI JAN 29 2016/
SHORT TERM...AS AN UPPER LEVEL TROUGH CENTERED TO THE NORTH MOVES
INLAND AND VERY COLD AIR ALOFT MOVES INTO THE AREA, SHOWERS WILL
SPREAD INLAND FROM THE NORTHWEST AND SNOW LEVELS WILL LOWER.
AHEAD OF THE SHOWERS, RAIN AND SNOW WILL CONTINUE OVER PORTIONS OF
SOUTHERN OREGON AND ACROSS NORTHERN CALIFORNIA LATE THIS AFTERNOON
AND THIS EVENING. SHOWERS ARE EXPECTED TO INCREASE OVER THE AREA
TODAY AND SATURDAY MORNING.
SNOW LEVELS ARE CURRENTLY AROUND 3500 TO 4000 FEET WEST OF THE
CASCADES IN SOUTHERN OREGON AND 4000 TO 6000 FEET EAST OF THE
CASCADES AND IN NORTHERN CALIFORNIA. SNOW LEVELS WILL LOWER TO
2500 FEET THIS EVENING FROM THE SOUTHERN OREGON CASCADES WESTWARD
AND BETWEEN 2500 TO 4500 FEET EAST OF THE CASCADES AND IN NORTHERN
CALIFORNIA. THEN SNOW LEVELS DROP FURTHER, LOWERING DOWN TO 2000
FEET LATE TONIGHT AND SATURDAY MORNING. LOW SNOW LEVELS COMBINED
WITH INCREASING SHOWER ACTIVITY TONIGHT AND SATURDAY MORNING WILL
BRING LIGHT TO MODERATE SNOW ACCUMULATIONS TO THE AREA, WITH
MODERATE SNOW OVER THE SOUTHERN OREGON CASCADES AND THE WESTERN
SLOPES OF THE SOUTHERN OREGON CASCADES WHERE AROUND 1 TO 4 INCHES
IS EXPECTED ABOVE 2000 FEET AND 4 TO 6 INCHES ABOVE 3000 FEET
WITH LOCALLY HIGHER AMOUNTS UP TO 10 INCHES ABOVE 5500 FEET,
ESPECIALLY IN THE CRATER LAKE AREA. LOCALLY SNOW OR A RAIN/SNOW
MIX MAY FALL DOWN TO 1500 FEET ELEVATION SATURDAY MORNING BUT
EXPECT LITTLE IF ANY ACCUMULATIONS.
SHOWERS ARE FORECAST TO CONTINUE THROUGH THE DAY SATURDAY WITH
ADDITIONAL LIGHT SNOW ACCUMULATIONS AND SNOW LEVELS AROUND 2500
TO 3000 FEET.
SATURDAY NIGHT INTO SUNDAY, COLDER CONDITIONS WILL DEVELOP AS THE
UPPER LEVEL TROUGH BECOMES CENTERED OVER THE AREA. MODELS ARE IN
GOOD AGREEMENT THAT SHOWERS WILL BE MAINLY LIMITED TO THE COASTAL
AREAS AND OVER THE COASTAL WATERS SATURDAY NIGHT AND SUNDAY. THEN
AS DAYTIME INSTABILITY INCREASES WITH THE COLD TROUGH OVERHEAD,
EXPECT SHOWERS TO INCREASE DURING THE DAY SUNDAY, MAINLY OVER THE
HIGHER TERRAIN FROM THE CASCADES WEST. SNOW LEVELS ARE FORECAST
AROUND 500 TO 1500 FEET SUNDAY MORNING RISING TO 2000 TO 2500
FEET IN THE AFTERNOON. THE FLOW ALOFT WILL BE MORE NORTHERLY AND
NOT AS MOIST. SO, SNOW ACCUMULATIONS ARE FORECAST TO REMAIN LIGHT.
MODELS SHOW DIFFERENCES IN THE AMOUNT OF SHOWER ACTIVITY AND
COVERAGE FOR SUNDAY INTO SUNDAY NIGHT THOUGH AND WILL NEED TO
MONITOR THE FORECAST DURING THIS PERIOD.
LONG TERM...MONDAY THROUGH FRIDAY...HIGH PRESSURE AND UPPER LEVEL
RIDGING WILL BEGIN TO RETURN MONDAY, AND THIS SHOULD BRING A
DRYING TREND TO THE FORECAST AREA. THE UPPER LEVEL FLOW WILL BE
FROM THE NORTHWEST THROUGH ABOUT WEDNESDAY NIGHT OR THURSDAY, AND
THIS WILL PROVIDE AN OPPORTUNITY FOR A SHORTWAVE TO TRAVERSE OVER
THE REGION TUESDAY AND TUESDAY NIGHT. THERE IS SOME DIFFERENCE
BETWEEN THE ECMWF AND GFS SOLUTION REGARDING THIS WAVE, WITH THE
GFS PRODUCING A STRONGER WAVE THAT MOVES DIRECTLY OVER SOUTHERN
OREGON, WHILE THE ECMWF SHOWS A WEAKER WAVE SLIDING BY JUST TO OUR
NORTH. WITH ENSEMBLES SHOWING A WIDE RANGE OF VARIABILITY DURING
THIS TIME, CONFIDENCE IS LOW IN EITHER SPECIFIC SOLUTION. HAVE
THEREFORE TRENDED TOWARDS A GENERAL BLEND, AND KEPT A SLIGHT
CHANCE OR CHANCE OF PRECIPITATION FROM TUESDAY INTO EARLY
WEDNESDAY MORNING. SNOW LEVELS DURING THIS SYSTEM WILL REMAIN
BELOW 3000 FEET, AND MAY EVEN APPROACH THE VALLEY FLOORS AT TIMES,
BUT AS PRECIPITATION SHOULD BE LIGHT, NO MAJOR IMPACTS ARE
EXPECTED.
AFTER ANOTHER BRIEF PERIOD OF HIGH PRESSURE AND DRIER CONDITIONS
WEDNESDAY NIGHT INTO THURSDAY MORNING, ANOTHER WAVE IS EXPECTED
THURSDAY AFTERNOON. MODELS ARE IN SURPRISINGLY GOOD AGREEMENT FOR
THIS WAVE, BUT AS THERE IS LITTLE TO INDICATE THAT THIS WOULD BE A
STRONG SYSTEM, HAVE KEPT PRECIPITATION CHANCES ON THE LOW SIDE. SNOW
LEVELS SHOULD JUMP UP TO ABOUT 5000 FEET, SO AGAIN, LITTLE IMPACT IS
EXPECTED. HIGH PRESSURE AND RIDGING WILL THEN RETURN AND REMAIN IN
CONTROL THROUGH THE END OF THE TERM. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR ORZ025.
WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR ORZ026.
CA...WINTER WEATHER ADVISORY UNTIL 11 PM PST THIS EVENING FOR
CAZ083-085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SUNDAY
FOR PZZ350-356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
FOR PZZ370-376.
$$
NSK/BPN/FJB
AREA FORECAST DISCUSSION
NWS MEDFORD OR
1035 PM PST FRI JAN 29 2016
.UPDATED AVIATION DISCUSSION.
.DISCUSSION...A COLD FRONT HAS SWEPT THROUGH THE FORECAST AREA...AND
THE RELATIVELY WARM PATTERN WITH HIGH SNOW LEVELS HAS ENDED. SNOW
LEVELS ARE NOW ABOUT 3500 FEET AND WILL CONTINUE TO FALL
OVERNIGHT. FAVORABLE JET DYNAMICS IS ENHANCING PRECIPITATION OVER
NORTHEAST CALIFORNIA...AND WE HAVE ISSUED A WINTER WEATHER
ADVISORY AT WSWMFR FOR SEVERAL INCHES OF SNOW EXPECTED THIS
EVENING IN LOCATIONS SUCH AS ALTURAS. THE HRRR SHOWED THIS ENHANCED
AREA OF PCPN THE BEST...AND IT SHOWS SNOW DIMINISHING THERE BY
MIDNIGHT. ELSEWHERE...SNOW IS EXPECTED TO IMPACT THE FOOTHILLS OF
THE CASCADES TONIGHT IN JACKSON AND DOUGLAS COUNTIES AND THE WSW
CONTINUES FOR THOSE AREAS INTO SATURDAY MORNING.
WESTERLY FLOW ALOFT WILL HELP BRING 3-6 MORE INCHES OF SNOW TO THE
CASCADES TONIGHT INTO TOMORROW. TRAVELERS INTO THE MOUNTAINS CAN
EXPECT SOME SNOW COVERED ROADS AND LOWER VISIBILITIES THROUGH
SATURDAY.
SATURDAY WILL FEATURE THE AFOREMENTIONED RAIN AND SNOW
SHOWERS...WITH SNOW LEVELS DIPPING TO ABOUT 2000 FEET. NAM12 OUTPUT
SUGGESTS ENOUGH INSTABILITY FOR THUNDERSTORMS FOR MUCH OF THE WEST
SIDE...GENERALLY ALONG AND WEST OF I-5.
SEE THE PREVIOUS DISCUSSION BELOW FOR MORE DETAILS ON THE SHOWERY
AND COLD CONDITIONS EXPECTED THIS WEEKEND.
&&
.AVIATION...FOR THE 30/06Z TAF CYCLE...MVFR/IFR AND NEAR TOTAL
TERRAIN OBSCURATION IN SHOWERS IS EXPECTED THROUGH THE NIGHT. THE
WORST CONDITIONS WILL LIKELY BE IN THE CASCADES AND IN MODOC COUNTY
WHERE SNOW SHOWERS WILL BRING IFR VISIBILITIES. ANOTHER WEAK
DISTURBANCE WILL BRING A MORE FOCUSED PERIOD OF SHOWERS TO THE COAST
AROUND MIDNIGHT WITH CIGS POTENTIALLY LOWERING TO MVFR AT TIMES.
SCATTERED TO WIDESPREAD SHOWERS ARE EXPECTED ON SATURDAY...MAINLY
FROM THE CASCADES WEST. ADDITIONALLY...THUNDERSTORMS ARE POSSIBLE
OVERNIGHT INTO TOMORROW OVER THE COASTAL WATERS TO AREAS JUST
INLAND. FB/SK
&&
.MARINE...UPDATED 800 PM PST FRI 29 JAN 2016...STEEP SEAS AND WEST
SWELL WILL GRADUALLY SUBSIDE OVER THE WEEKEND BUT WILL REMAIN
HAZARDOUS TO SMALL CRAFT UNTIL EARLY NEXT WEEK. HIGH PRESSURE WILL
BUILD INTO THE WATERS LATE THIS WEEKEND. WEAK LOW PRESSURE WILL
ARRIVE TUESDAY MORNING BUT WINDS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. SK
&&
.PREV DISCUSSION... /ISSUED 235 PM PST FRI JAN 29 2016/
SHORT TERM...AS AN UPPER LEVEL TROUGH CENTERED TO THE NORTH MOVES
INLAND AND VERY COLD AIR ALOFT MOVES INTO THE AREA, SHOWERS WILL
SPREAD INLAND FROM THE NORTHWEST AND SNOW LEVELS WILL LOWER.
AHEAD OF THE SHOWERS, RAIN AND SNOW WILL CONTINUE OVER PORTIONS OF
SOUTHERN OREGON AND ACROSS NORTHERN CALIFORNIA LATE THIS AFTERNOON
AND THIS EVENING. SHOWERS ARE EXPECTED TO INCREASE OVER THE AREA
TODAY AND SATURDAY MORNING.
SNOW LEVELS ARE CURRENTLY AROUND 3500 TO 4000 FEET WEST OF THE
CASCADES IN SOUTHERN OREGON AND 4000 TO 6000 FEET EAST OF THE
CASCADES AND IN NORTHERN CALIFORNIA. SNOW LEVELS WILL LOWER TO
2500 FEET THIS EVENING FROM THE SOUTHERN OREGON CASCADES WESTWARD
AND BETWEEN 2500 TO 4500 FEET EAST OF THE CASCADES AND IN NORTHERN
CALIFORNIA. THEN SNOW LEVELS DROP FURTHER, LOWERING DOWN TO 2000
FEET LATE TONIGHT AND SATURDAY MORNING. LOW SNOW LEVELS COMBINED
WITH INCREASING SHOWER ACTIVITY TONIGHT AND SATURDAY MORNING WILL
BRING LIGHT TO MODERATE SNOW ACCUMULATIONS TO THE AREA, WITH
MODERATE SNOW OVER THE SOUTHERN OREGON CASCADES AND THE WESTERN
SLOPES OF THE SOUTHERN OREGON CASCADES WHERE AROUND 1 TO 4 INCHES
IS EXPECTED ABOVE 2000 FEET AND 4 TO 6 INCHES ABOVE 3000 FEET
WITH LOCALLY HIGHER AMOUNTS UP TO 10 INCHES ABOVE 5500 FEET,
ESPECIALLY IN THE CRATER LAKE AREA. LOCALLY SNOW OR A RAIN/SNOW
MIX MAY FALL DOWN TO 1500 FEET ELEVATION SATURDAY MORNING BUT
EXPECT LITTLE IF ANY ACCUMULATIONS.
SHOWERS ARE FORECAST TO CONTINUE THROUGH THE DAY SATURDAY WITH
ADDITIONAL LIGHT SNOW ACCUMULATIONS AND SNOW LEVELS AROUND 2500
TO 3000 FEET.
SATURDAY NIGHT INTO SUNDAY, COLDER CONDITIONS WILL DEVELOP AS THE
UPPER LEVEL TROUGH BECOMES CENTERED OVER THE AREA. MODELS ARE IN
GOOD AGREEMENT THAT SHOWERS WILL BE MAINLY LIMITED TO THE COASTAL
AREAS AND OVER THE COASTAL WATERS SATURDAY NIGHT AND SUNDAY. THEN
AS DAYTIME INSTABILITY INCREASES WITH THE COLD TROUGH OVERHEAD,
EXPECT SHOWERS TO INCREASE DURING THE DAY SUNDAY, MAINLY OVER THE
HIGHER TERRAIN FROM THE CASCADES WEST. SNOW LEVELS ARE FORECAST
AROUND 500 TO 1500 FEET SUNDAY MORNING RISING TO 2000 TO 2500
FEET IN THE AFTERNOON. THE FLOW ALOFT WILL BE MORE NORTHERLY AND
NOT AS MOIST. SO, SNOW ACCUMULATIONS ARE FORECAST TO REMAIN LIGHT.
MODELS SHOW DIFFERENCES IN THE AMOUNT OF SHOWER ACTIVITY AND
COVERAGE FOR SUNDAY INTO SUNDAY NIGHT THOUGH AND WILL NEED TO
MONITOR THE FORECAST DURING THIS PERIOD.
LONG TERM...MONDAY THROUGH FRIDAY...HIGH PRESSURE AND UPPER LEVEL
RIDGING WILL BEGIN TO RETURN MONDAY, AND THIS SHOULD BRING A
DRYING TREND TO THE FORECAST AREA. THE UPPER LEVEL FLOW WILL BE
FROM THE NORTHWEST THROUGH ABOUT WEDNESDAY NIGHT OR THURSDAY, AND
THIS WILL PROVIDE AN OPPORTUNITY FOR A SHORTWAVE TO TRAVERSE OVER
THE REGION TUESDAY AND TUESDAY NIGHT. THERE IS SOME DIFFERENCE
BETWEEN THE ECMWF AND GFS SOLUTION REGARDING THIS WAVE, WITH THE
GFS PRODUCING A STRONGER WAVE THAT MOVES DIRECTLY OVER SOUTHERN
OREGON, WHILE THE ECMWF SHOWS A WEAKER WAVE SLIDING BY JUST TO OUR
NORTH. WITH ENSEMBLES SHOWING A WIDE RANGE OF VARIABILITY DURING
THIS TIME, CONFIDENCE IS LOW IN EITHER SPECIFIC SOLUTION. HAVE
THEREFORE TRENDED TOWARDS A GENERAL BLEND, AND KEPT A SLIGHT
CHANCE OR CHANCE OF PRECIPITATION FROM TUESDAY INTO EARLY
WEDNESDAY MORNING. SNOW LEVELS DURING THIS SYSTEM WILL REMAIN
BELOW 3000 FEET, AND MAY EVEN APPROACH THE VALLEY FLOORS AT TIMES,
BUT AS PRECIPITATION SHOULD BE LIGHT, NO MAJOR IMPACTS ARE
EXPECTED.
AFTER ANOTHER BRIEF PERIOD OF HIGH PRESSURE AND DRIER CONDITIONS
WEDNESDAY NIGHT INTO THURSDAY MORNING, ANOTHER WAVE IS EXPECTED
THURSDAY AFTERNOON. MODELS ARE IN SURPRISINGLY GOOD AGREEMENT FOR
THIS WAVE, BUT AS THERE IS LITTLE TO INDICATE THAT THIS WOULD BE A
STRONG SYSTEM, HAVE KEPT PRECIPITATION CHANCES ON THE LOW SIDE. SNOW
LEVELS SHOULD JUMP UP TO ABOUT 5000 FEET, SO AGAIN, LITTLE IMPACT IS
EXPECTED. HIGH PRESSURE AND RIDGING WILL THEN RETURN AND REMAIN IN
CONTROL THROUGH THE END OF THE TERM. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR ORZ025.
WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR ORZ026.
CA...WINTER WEATHER ADVISORY UNTIL 11 PM PST THIS EVENING FOR
CAZ083-085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SUNDAY
FOR PZZ350-356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
FOR PZZ370-376.
$$
NSK/BPN/FJB
AREA FORECAST DISCUSSION
NWS MEDFORD OR
814 PM PST FRI JAN 29 2016
.DISCUSSION...A COLD FRONT HAS SWEPT THROUGH THE FORECAST AREA...AND
THE RELATIVELY WARM PATTERN WITH HIGH SNOW LEVELS HAS ENDED. SNOW
LEVELS ARE NOW ABOUT 3500 FEET AND WILL CONTINUE TO FALL
OVERNIGHT. FAVORABLE JET DYNAMICS IS ENHANCING PRECIPITATION OVER
NORTHEAST CALIFORNIA...AND WE HAVE ISSUED A WINTER WEATHER
ADVISORY AT WSWMFR FOR SEVERAL INCHES OF SNOW EXPECTED THIS
EVENING IN LOCATIONS SUCH AS ALTURAS. THE HRRR SHOWED THIS
ENHANCED AREA OF PCPN THE BEST...AND IT SHOWS SNOW DIMINISHING
THERE IN BY MIDNIGHT. ELSEWHERE...SNOW IS EXPECTED TO IMPACT THE
FOOTHILLS OF THE CASCADES TONIGHT IN JACKSON AND DOUGLAS COUNTIES
AND THE WSW CONTINUES FOR THOSE AREAS INTO SATURDAY MORNING.
WESTERLY FLOW ALOFT WILL HELP BRING 3-6 MORE INCHES OF SNOW TO THE
CASCADES TONIGHT INTO TOMORROW. TRAVELERS INTO THE MOUNTAINS CAN
EXPECT SOME SNOW COVERED ROADS AND LOWER VISIBILITIES THROUGH
SATURDAY.
SATURDAY WILL FEATURE THE AFOREMENTIONED RAIN AND SNOW
SHOWERS...WITH SNOW LEVELS DIPPING TO ABOUT 2000 FEET. NAM12 OUTPUT
SUGGESTS ENOUGH INSTABILITY FOR THUNDERSTORMS FOR MUCH OF THE WEST
SIDE...GENERALLY ALONG AND WEST OF I-5.
SEE THE PREVIOUS DISCUSSION BELOW FOR MORE DETAILS ON THE SHOWERY
AND COLD CONDITIONS EXPECTED THIS WEEKEND.
&&
.AVIATION...FOR THE 30/00Z TAF CYCLE...MVFR/IFR AND NEAR TOTAL
TERRAIN OBSCURATION IN RAIN SHOWERS IS EXPECTED OVERNIGHT. SATELLITE
IMAGERY SHOWS A SMALL BREAK IN CLOUDS AT KOTH BUT WE EXPECT UPSTREAM
CLOUDS TO FILL IN LATER THIS EVENING. ANOTHER WEAK DISTURBANCE WILL
BRING LIGHT SHOWERS TO THE COAST AROUND MIDNIGHT WITH CIGS LOWERING
TO MVFR AT TIMES. TO THE EAST SNOW SHOWERS WILL MOVE THROUGH THE
KLAMATH BASIN THIS EVENING WITH CONDITIONS LOWERING TO MVFR FOR MOST
OF THE NIGHT. THERE COULD BE BRIEF IFR PERIODS IN MODERATE SNOW
SHOWERS. /FB
&&
.MARINE...UPDATED 230 PM PST FRI 29 JAN 2016...STEEP SEAS AND
WEST SWELL WILL GRADUALLY SUBSIDE OVER THE WEEKEND BUT WILL
REMAIN HAZARDOUS TO SMALL CRAFT UNTIL EARLY NEXT WEEK. HIGH
PRESSURE WILL BUILD INTO THE WATERS LATE THIS WEEKEND. WEAK LOW
PRESSURE WILL ARRIVE TUESDAY MORNING BUT WINDS SHOULD REMAIN BELOW
SMALL CRAFT ADVISORY CRITERIA. /FB
&&
.PREV DISCUSSION... /ISSUED 235 PM PST FRI JAN 29 2016/
SHORT TERM...AS AN UPPER LEVEL TROUGH CENTERED TO THE NORTH MOVES
INLAND AND VERY COLD AIR ALOFT MOVES INTO THE AREA, SHOWERS WILL
SPREAD INLAND FROM THE NORTHWEST AND SNOW LEVELS WILL LOWER.
AHEAD OF THE SHOWERS, RAIN AND SNOW WILL CONTINUE OVER PORTIONS OF
SOUTHERN OREGON AND ACROSS NORTHERN CALIFORNIA LATE THIS AFTERNOON
AND THIS EVENING. SHOWERS ARE EXPECTED TO INCREASE OVER THE AREA
TODAY AND SATURDAY MORNING.
SNOW LEVELS ARE CURRENTLY AROUND 3500 TO 4000 FEET WEST OF THE
CASCADES IN SOUTHERN OREGON AND 4000 TO 6000 FEET EAST OF THE
CASCADES AND IN NORTHERN CALIFORNIA. SNOW LEVELS WILL LOWER TO
2500 FEET THIS EVENING FROM THE SOUTHERN OREGON CASCADES WESTWARD
AND BETWEEN 2500 TO 4500 FEET EAST OF THE CASCADES AND IN NORTHERN
CALIFORNIA. THEN SNOW LEVELS DROP FURTHER, LOWERING DOWN TO 2000
FEET LATE TONIGHT AND SATURDAY MORNING. LOW SNOW LEVELS COMBINED
WITH INCREASING SHOWER ACTIVITY TONIGHT AND SATURDAY MORNING WILL
BRING LIGHT TO MODERATE SNOW ACCUMULATIONS TO THE AREA, WITH
MODERATE SNOW OVER THE SOUTHERN OREGON CASCADES AND THE WESTERN
SLOPES OF THE SOUTHERN OREGON CASCADES WHERE AROUND 1 TO 4 INCHES
IS EXPECTED ABOVE 2000 FEET AND 4 TO 6 INCHES ABOVE 3000 FEET
WITH LOCALLY HIGHER AMOUNTS UP TO 10 INCHES ABOVE 5500 FEET,
ESPECIALLY IN THE CRATER LAKE AREA. LOCALLY SNOW OR A RAIN/SNOW
MIX MAY FALL DOWN TO 1500 FEET ELEVATION SATURDAY MORNING BUT
EXPECT LITTLE IF ANY ACCUMULATIONS.
SHOWERS ARE FORECAST TO CONTINUE THROUGH THE DAY SATURDAY WITH
ADDITIONAL LIGHT SNOW ACCUMULATIONS AND SNOW LEVELS AROUND 2500
TO 3000 FEET.
SATURDAY NIGHT INTO SUNDAY, COLDER CONDITIONS WILL DEVELOP AS THE
UPPER LEVEL TROUGH BECOMES CENTERED OVER THE AREA. MODELS ARE IN
GOOD AGREEMENT THAT SHOWERS WILL BE MAINLY LIMITED TO THE COASTAL
AREAS AND OVER THE COASTAL WATERS SATURDAY NIGHT AND SUNDAY. THEN
AS DAYTIME INSTABILITY INCREASES WITH THE COLD TROUGH OVERHEAD,
EXPECT SHOWERS TO INCREASE DURING THE DAY SUNDAY, MAINLY OVER THE
HIGHER TERRAIN FROM THE CASCADES WEST. SNOW LEVELS ARE FORECAST
AROUND 500 TO 1500 FEET SUNDAY MORNING RISING TO 2000 TO 2500
FEET IN THE AFTERNOON. THE FLOW ALOFT WILL BE MORE NORTHERLY AND
NOT AS MOIST. SO, SNOW ACCUMULATIONS ARE FORECAST TO REMAIN LIGHT.
MODELS SHOW DIFFERENCES IN THE AMOUNT OF SHOWER ACTIVITY AND
COVERAGE FOR SUNDAY INTO SUNDAY NIGHT THOUGH AND WILL NEED TO
MONITOR THE FORECAST DURING THIS PERIOD.
LONG TERM...MONDAY THROUGH FRIDAY...HIGH PRESSURE AND UPPER LEVEL
RIDGING WILL BEGIN TO RETURN MONDAY, AND THIS SHOULD BRING A
DRYING TREND TO THE FORECAST AREA. THE UPPER LEVEL FLOW WILL BE
FROM THE NORTHWEST THROUGH ABOUT WEDNESDAY NIGHT OR THURSDAY, AND
THIS WILL PROVIDE AN OPPORTUNITY FOR A SHORTWAVE TO TRAVERSE OVER
THE REGION TUESDAY AND TUESDAY NIGHT. THERE IS SOME DIFFERENCE
BETWEEN THE ECMWF AND GFS SOLUTION REGARDING THIS WAVE, WITH THE
GFS PRODUCING A STRONGER WAVE THAT MOVES DIRECTLY OVER SOUTHERN
OREGON, WHILE THE ECMWF SHOWS A WEAKER WAVE SLIDING BY JUST TO OUR
NORTH. WITH ENSEMBLES SHOWING A WIDE RANGE OF VARIABILITY DURING
THIS TIME, CONFIDENCE IS LOW IN EITHER SPECIFIC SOLUTION. HAVE
THEREFORE TRENDED TOWARDS A GENERAL BLEND, AND KEPT A SLIGHT
CHANCE OR CHANCE OF PRECIPITATION FROM TUESDAY INTO EARLY
WEDNESDAY MORNING. SNOW LEVELS DURING THIS SYSTEM WILL REMAIN
BELOW 3000 FEET, AND MAY EVEN APPROACH THE VALLEY FLOORS AT TIMES,
BUT AS PRECIPITATION SHOULD BE LIGHT, NO MAJOR IMPACTS ARE
EXPECTED.
AFTER ANOTHER BRIEF PERIOD OF HIGH PRESSURE AND DRIER CONDITIONS
WEDNESDAY NIGHT INTO THURSDAY MORNING, ANOTHER WAVE IS EXPECTED
THURSDAY AFTERNOON. MODELS ARE IN SURPRISINGLY GOOD AGREEMENT FOR
THIS WAVE, BUT AS THERE IS LITTLE TO INDICATE THAT THIS WOULD BE A
STRONG SYSTEM, HAVE KEPT PRECIPITATION CHANCES ON THE LOW SIDE. SNOW
LEVELS SHOULD JUMP UP TO ABOUT 5000 FEET, SO AGAIN, LITTLE IMPACT IS
EXPECTED. HIGH PRESSURE AND RIDGING WILL THEN RETURN AND REMAIN IN
CONTROL THROUGH THE END OF THE TERM. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR ORZ025.
WINTER WEATHER ADVISORY UNTIL 10 AM PST SATURDAY FOR ORZ026.
CA...WINTER WEATHER ADVISORY UNTIL 11 PM PST THIS EVENING FOR
CAZ083-085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST SUNDAY
FOR PZZ350-356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
FOR PZZ370-376.
$$
NSK/BPN/FJB
Area Forecast Discussion
National Weather Service Spokane WA
1030 PM PST FRI JAN 29 2016
.SYNOPSIS...
A strong low pressure area will track through the northeast corner
of Washington into extreme north Idaho this evening spreading
widespread snow, with most of the significant accumulations
occurring over the mountains. The low will also deliver windy
conditions to southeast Washington and north central Idaho this
evening. The low will be followed by a trough of low pressure
which will settle into the region Saturday and lingers through
Monday, delivering seasonal temperatures with a chance of snow
showers. A more organized system approach again toward next
Thursday.
&&
.DISCUSSION...
The surface low that brought winds to southeast WA and the
southern Id Panhandle has shifted east into Western MT this
evening. The winds have subsided and cancelled the advisory early.
Elevated winds will continue there this evening and decrease to
about 10 mph overnight and then pick up again Saturday late
morning or early afternoon. These winds will only last a few hours
and will be below advisory criteria. Both the NAM and HRRR are
showing some energy moving trough the Palouse in the westerly
flow overnight. They are suggesting some snow sticking to the
ground and will be updating the forecast tonight for that.
Generally will expect less than an inch of snowfall.
Light snow showers will continue across extreme NE WA and north
ID this evening and then decrease through the night.
The winter weather advisory for the Cascades will end at 10pm,
but snow is expected to continue through the night along the
crest. Models are showing a convergence zone setting up right
along the crest north of Stevens Pass, but south of Lake Chelan in
Chelan County. They suggest the band of moderate to heavy snow
will continue through the night and Saturday morning before
tapering off in the afternoon. Will be updating forecast to
account for this snowfall. /Nisbet
&&
.AVIATION...
06Z TAFS: Winds have decreased across most of the region. Expect
some stratus to develop btwn 08-10Z for eastern TAF sites. Latest
NAM and HRRR is showing some -shsn developing aft 10Z for eastern
TAF locations. HRRR has been waffling a bit btwn runs, but have
kept it in the TAF. More confident about KPUW than other sites.
The -shsn potential ends btwn 15 and 18Z with clouds generally
lifting and decreasing through the afternoon. The potential exists
for stratus to set up in the Columbia Basin and Wenatchee area as
well. Am more confident about KEAT than KMWH. The stratus will
linger around through the morning and then break up in the aftn.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 29 37 25 35 25 34 / 10 20 20 20 20 20
Coeur d`Alene 31 36 27 35 26 33 / 10 40 20 40 20 20
Pullman 32 38 28 36 25 35 / 70 40 20 20 20 40
Lewiston 36 45 33 42 31 40 / 40 40 20 20 20 40
Colville 30 35 27 35 25 33 / 10 20 10 30 20 20
Sandpoint 32 35 28 34 27 32 / 60 40 30 50 30 20
Kellogg 30 33 26 32 25 31 / 60 50 40 50 30 40
Moses Lake 30 42 27 39 26 38 / 0 10 10 10 10 10
Wenatchee 31 39 29 38 28 36 / 0 10 10 10 10 10
Omak 26 35 24 34 23 32 / 0 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
900 PM PST FRI JAN 29 2016
.SYNOPSIS...AN UPPER TROUGH OVER THE PACIFIC NORTHWEST WILL MOVE
SOUTH TO CALIFORNIA OVER THE WEEKEND. THE AIR IS COOL AND UNSTABLE
WITH SHOWERS OVER WESTERN WASHINGTON. THE WEATHER PATTERN WILL BE
COOL AND SHOWERY INTO EARLY NEXT WEEK.
&&
.SHORT TERM...CONVECTIVE CLOUDS STRETCH WELL OFFSHORE ON SATELLITE
IMAGERY THIS EVENING. THERE HAVE BEEN A FEW TSTMS WITH SMALL HAIL
BUT THEY SEEM TO HAVE BEEN FEW AND FAR BETWEEN CONSIDERING THE COLD
AIR ALOFT WHICH WAS -33C AT 500MB ON THE KUIL SOUNDING THIS
AFTERNOON. A RATHER LARGE PATCH OF COLD AIR ALOFT WILL BE SINKING
SOUTH OVER THE REGION THROUGH THE WEEKEND SO THE SNOW LEVEL WILL BE
ON THE LOW SIDE. PUGET SOUND CONVERGENCE ZONE ACTIVITY MIGHT OCCUR
AT TIMES INTO SUNDAY AND MONDAY AS DISTURBANCES MOVE THROUGH THE
AREA IN THE COLD AIR ALOFT. THE 00Z UW MM5NAM HAD SOME DECENT SNOW
IN THE OLYMPICS ON SUNDAY...THEN MOSTLY IN THE CENTRAL CASCADES MON
AND TUE.
.LONG TERM...A TRANSITORY UPPER LEVEL RIDGE WILL MOVE OVER THE AREA
WED AND WED NITE. A WEAKENING FRONT WILL REACH THE AREA
THURSDAY...POSSIBLY FOLLOWED BY STRONGER RIDGING TOWARD THE END OF
NEXT WEEK.
&&
.AVIATION...AN UPPER LEVEL TROUGH WILL LINGER OVER THE REGION
THROUGH THE WEEKEND. MODERATE WLY FLOW ALOFT TONIGHT WILL BECOME
LIGHT SW FLOW ALOFT SATURDAY AND SATURDAY NIGHT. WEAKLY UNSTABLE
WITH ISOLATED THUNDERSTORMS UNTIL MIDNIGHT. THE CHANCE OF TS AT ANY
TERMINAL IS LESS THAN 20 PERCENT SO WILL LEAVE OUT OF 06Z TAFS WHEN
ISSUED. MOIST AT ALL LEVELS. SHOWERS AND A POSSIBLE PUGET SOUND
CONVERGENCE ZONE COULD AFFECT THE KPAE TERMINAL AT TIMES THROUGH
SATURDAY MORNING.
KSEA...CIGS WILL BE SOMEWHAT VARIABLE TONIGHT AS SHOWERS PASS THE
TERMINALS AT TIMES. IT NOW APPEARS IT WILL REMAIN UNSTABLE ENOUGH
WITH SOME MIXING TO PREVENT ANY LOWER IFR CIGS FROM FORMING. MOST
LIKELY...VFR CONDITIONS WILL PERSIST THROUGH SATURDAY BUT A COULD
HOURS OF MVFR CANNOT BE RULES OUT LATE TONIGHT/EARLY SATURDAY
MORNING IF THE AIR MASS STABILIZES TEMPORARILY.
&&
.MARINE...A SURFACE TROUGH WILL MAINTAIN ONSHORE FLOW THROUGH
SATURDAY BUT GRADUALLY WEAKENING. LOW END SMALL CRAFT WINDS ARE
STILL POSSIBLE OVER MOST THE WATERS TONIGHT BUT WINDS WILL WANE BY
MORNING. SEAS WILL REMAIN NEAR 15 FEET SO A SMALL CRAFT FOR
HAZARDOUS SEAS COAST AND WEST ENTRANCE WILL GO INTO AFFECT AT 6 AM
WITH THE SMALL CRAFT FOR WINDS ENDS. HIGH PRESSURE WILL BRIEFLY
BUILD OVER THE WATERS ON MONDAY. A WEAKENING FRONTAL SYSTEM WILL
REACH THE AREA ON TUESDAY. DTM
&&
.HYDROLOGY...THE SKOKOMISH RIVER WILL CONTINUE RECEDING...AND IS
FORECAST TO FALL BELOW FLOOD STAGE LATE TONIGHT OR EARLY SATURDAY.
AFTER THAT...FLOODING IS NOT EXPECTED THROUGH NEXT WEEK.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER WEATHER ADVISORY UNTIL 3 PM PST SATURDAY FOR CASCADES OF
PIERCE AND LEWIS COUNTIES-CASCADES OF SNOHOMISH AND KING
COUNTIES-CASCADES OF WHATCOM AND SKAGIT COUNTIES.
HIGH SURF ADVISORY UNTIL 8 AM PST SATURDAY FOR CENTRAL COAST.
PZ...SMALL CRAFT ADVISORY UNTIL 6 AM PST SATURDAY FOR COASTAL WATERS.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 AM TO 6 PM PST
SATURDAY FOR THE COASTAL WATERS AND WEST ENTRANCE TO THE STRAIT.
SMALL CRAFT ADVISORY THROUGH 6 AM PST SATURDAY FOR THE ENTIRE
STRAIT OF JUAN DE FUCA...PUGET SOUND...AND NORTHERN INLAND WATERS.
SMALL CRAFT ADVISORY FOR ROUGH BAR THROUGH SATURDAY EVENING FOR
GRAYS HARBOR BAR.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
819 PM PST FRI JAN 29 2016
.SYNOPSIS...
A strong low pressure area will track through the northeast corner
of Washington into extreme north Idaho this evening spreading
widespread snow, with most of the significant accumulations
occurring over the mountains. The low will also deliver windy
conditions to southeast Washington and north central Idaho this
evening. The low will be followed by a trough of low pressure
which will settle into the region Saturday and lingers through
Monday, delivering seasonal temperatures with a chance of snow
showers. A more organized system approach again toward next
Thursday.
&&
.DISCUSSION...
The surface low that brought winds to southeast WA and the
southern Id Panhandle has shifted east into Western MT this
evening. The winds have subsided and cancelled the advisory early.
Elevated winds will continue there this evening and decrease to
about 10 mph overnight and then pick up again Saturday late
morning or early afternoon. These winds will only last a few hours
and will be below advisory criteria. Both the NAM and HRRR are
showing some energy moving trough the Palouse in the westerly
flow overnight. They are suggesting some snow sticking to the
ground and will be updating the forecast tonight for that.
Generally will expect less than an inch of snowfall.
Light snow showers will continue across extreme NE WA and north
ID this evening and then decrease through the night.
The winter weather advisory for the Cascades will end at 10pm,
but snow is expected to continue through the night along the
crest. Models are showing a convergence zone setting up right
along the crest north of Stevens Pass, but south of Lake Chelan in
Chelan County. They suggest the band of moderate to heavy snow
will continue through the night and Saturday morning before
tapering off in the afternoon. Will be updating forecast to
account for this snowfall. /Nisbet
&&
.AVIATION...
00Z TAFS: Tough aviation forecasts for most sites as strong low
pressure drifts from current position in NE WA near GEG and into
NW MT early this evening. The departing low will shift the main
threat of precipitation away from any of the forecast sites, with
the main problem then trending toward what to do about residual
cloud cover. The latest visible satellite imagery was showing
rapid clearing over the SE corner of WA and the southern Columbia
Basin so the forecasts for PUW LWS MWH and EAT will likely
feature VFR conditions for a while this evening. However there is
a fair chance that stratus redevelops sometime overnight. Just not
sure how high the clouds will be or when they will reform. Then
there is the question how long with the clouds persist into
Saturday. MOS guidance is all over the place so confidence is very
low. Another issue is the winds. LWS and PUW will see the
strongest winds with speeds of 20-30kts and gusts to 30-40kts
expected through 02Z. The most difficult forecasts will be the
GEG-SFF-COE ones. Low clouds will likely persist through most of
the night with IFR conditions, however there is clearing about 60
miles SW of GEG. We suspect some of that clearing could move into
GEG between 02-03z and perhaps to COE shortly thereafter. However
we aren`t confident that any of this clearing will persist long
as moist upslope sw flow behind recent precipitation is notorious
for reforming stratus in a hurry. The question would be would it
be the MVFR or IFR category. Whatever forms will likely persist
through most of the forecast period. fx/LN
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 29 37 25 35 25 34 / 10 20 20 20 20 20
Coeur d`Alene 31 36 27 35 26 33 / 20 40 20 40 20 20
Pullman 32 38 28 36 25 35 / 70 40 20 20 20 40
Lewiston 36 45 33 42 31 40 / 40 40 20 20 20 40
Colville 30 35 27 35 25 33 / 20 20 10 30 20 20
Sandpoint 32 35 28 34 27 32 / 80 40 30 50 30 20
Kellogg 30 33 26 32 25 31 / 90 50 40 50 30 40
Moses Lake 30 42 27 39 26 38 / 0 10 10 10 10 10
Wenatchee 31 39 29 38 28 36 / 20 10 10 10 10 10
Omak 26 35 24 34 23 32 / 0 10 10 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Winter Weather Advisory until 10 PM PST this evening for East
Slopes Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
1015 AM EST SAT JAN 30 2016
.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS NEW ENGLAND TODAY AND OFFSHORE INTO THE
ATLANTIC TONIGHT. A WARM FRONT WILL LIFT NORTHEAST ACROSS THE
REGION TONIGHT. EXPECT WARMER TEMPERATURES BEGINNING ON SUNDAY AND
LASTING THROUGH MUCH OF THE COMING WEEK. LOW PRESSURE WILL MOVE
OUT OF THE GREAT LAKES AND THROUGH THE SAINT LAWRENCE VALLEY ON
MONDAY... DRAGGING A COLD FRONT ACROSS NEW ENGLAND. THIS WILL COOL
TEMPERATURES SOMEWHAT BUT IT WILL STILL BE ABOVE NORMAL. A LARGER
STORM SYSTEM IS EXPECTED TO DEVELOP OVER THE MIDWEST NEXT WEEK AND
MOVE NORTHEAST THROUGH THE CENTRAL GREAT LAKES AND DEEP INTO
CANADA ON WEDNESDAY. THIS WILL SEND ANOTHER FRONTAL SYSTEM THROUGH
NEW ENGLAND ON WEDNESDAY AND WEDNESDAY NIGHT. COOLER HIGH PRESSURE
WILL BUILD IN OUT OF THE NORTHWEST BEHIND THE FRONT FOR THURSDAY.
LOW PRESSURE WILL DEVELOP OFF THE MID ATLANTIC COAST AND MOVE
NORTHEAST OFF THE COAST OF NEW ENGLAND ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1010 AM UPDATE...HAVE UPDATED THE FORECAST FOR THE REST OF THE DAY
AND INTO THIS EVENING BASED ON LATEST TRENDS IN OBSERVATIONAL AND
MODEL DATA. HAVE INCREASED POPS FOR VERY LATE THIS AFTERNOON AND
EVENING FOR NORTHERNMOST NH AND THE WESTERN ME MOUNTAINS BASED ON
A BLEND OF LATEST MODEL GUIDANCE SUCH AS THE HRRR AND SREF. SHOULD
BE A BAND OF MEASURABLE SNOW/SNOW SHOWERS THAT MOVES THROUGH THAT
AREA A FEW HOURS EITHER SIDE OF 00Z. SOME MODEL DATA HINT AT
DEVELOPMENT OF SNOW SHOWERS /MAYBE SOME RAIN SHOWERS ON IMMEDIATE
COAST/ ON THE COASTAL PLAIN...ESPECIALLY THE MIDCOAST THIS
EVENING AS LOW LEVEL JET BEGINS TO STRENGTHEN. HAVE BLENDED IN
SOME LOWER POPS THERE TO ACCOUNT FOR THIS POSSIBILITY.
OTHERWISE...EXPECT INCREASING CLOUDS THE REST OF THE DAY.
PREVIOUSLY...
HIGH PRESSURE BUILDS IN BRIEFLY TODAY... BRINGING AN END TO THE
LIGHT SNOW. TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL WITH
HIGHS IN THE 30S TO NEAR 40 DEGREES. CLOUD COVER STILL STUCK TO
THE NORTHWEST OF THE MOUNTAINS SHOULD DISSIPATE AS THE DAY GOES ON
AND WINDS SHIFT FROM NORTHWEST TO SOUTH OR SOUTHWEST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
7AM UPDATE...
CLOUD COVER STUCK TO THE WEST OF THE MOUNTAINS HAS SHOWN SIGNS OF
RETREATING OVER THE PAST FEW HOURS AS DRIER AIR WORKS ITS WAY IN
FROM THE SOUTHWEST AND HELPS MIX OUT THOSE STUBBORN CLOUDS. IT
WILL NOT LIKELY BE SUNNY FOR LONG AS MID AND HIGH LEVEL CLOUDS
ARE ALREADY SPILLING INTO NEW YORK STATE. MADE A FEW ADJUSTMENTS
TO HOURLY TEMPERATURES BUT OTHERWISE NO SIGNIFICANT CHANGES WERE
NEEDED TO THE CURRENT FORECAST.
ORIGINAL DISCUSSION...
HIGH PRESSURE MOVES EAST TONIGHT WITH A SHORTWAVE TROUGH LIFTING
THROUGH ONTARIO AND QUEBEC. THIS FEATURE MAY BE JUST CLOSE ENOUGH
TO PROVIDE A FEW LIGHT SNOW SHOWERS IN NORTHERN AREAS TONIGHT BUT
NOT EXPECTING MUCH ACCUMULATION IF IT DOES OCCUR. THE MAIN EFFECT
WILL BE A SHIFT TO SOUTHERLY WINDS WITH WARMER AIR MOVING IN FROM
THE SOUTH. BY SUNDAY TEMPERATURES WILL BE WELL INTO THE 40S ACROSS
THE ENTIRE AREA. INCREASING DEWPOINTS AS WELL SHOULD ALLOW FOR
SOME MELTING OF THE REMNANT SNOW PACK.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
NEXT WEEK CAN BEST BE CHARACTERIZED BY WARM AND WET CONDITIONS.
THERE IS A SMALL CHANCE FOR A COASTAL LOW BRINGING SNOW TO THE
REGION BY FRIDAY.
ANOTHER AREA OF LOW PRESSURE THIS WINTER WILL PASS TO OUR
WEST...LEAVING NORTHERN NEW ENGLAND ON THE WARM SIDE OF THE
EQUATION. THERE MAY BE A MIX AT THE ONSET OF THE PRECIPITATION OVER
FAR NORTHERN AREAS...OTHERWISE THIS WILL BE A RAIN EVENT WITH MILD
TEMPERATURES.
READINGS QUICKLY SOAR THROUGH THE 40S ON MONDAY DESPITE THE
PASSAGE OF A COLD FRONT WITH SOME AREAS OVER SOUTHERN NEW
HAMPSHIRE TOPPING OUT AT 50 DEGREES.
AFTER A BRIEF RIDGE OF HIGH PRESSURE ON TUESDAY...ANOTHER LOW
PRESSURE WILL UNDERGO CYCLOGENESIS AND CROSS OVER THE GREAT LAKES
ON WEDNESDAY. THIS WILL BRING A MIX OF PRECIPITATION INTO
NORTHERN AREAS...TO BE FOLLOWED BY RAIN IN ALL SECTIONS.
SIMILAR TO TUESDAY...HIGH PRESSURE WILL BRIEFLY MAKE AN
APPEARANCE ON THURSDAY. THIS WILL BE FOLLOWED BY LOW PRESSURE OFF
THE MID ATLANTIC COASTLINE MOVING NORTHEAST ON FRIDAY. THE GFS IS
MORE VIGOROUS WITH THIS SYSTEM AS COMPARED TO THE NEW EURO RUN.
CONFIDENCE LEVELS ARE LOW WITH THE FORECAST TRACK OF THE SURFACE
LOW AS THERE IS A LARGE SPREAD IN THE ENSEMBLE GUIDANCE.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...MAINLY VFR EXPECTED TODAY EXCEPT PERHAPS IN THE
MOUNTAINS WHERE SNOW SHOWERS MAY LOWER CONDITIONS 3 HOURS EITHER
SIDE OF 00Z THIS EVENING.
LONG TERM...CONDITIONS LOWER TO IFR WITH LOCALIZED LIFR ON SUNDAY
NIGHT WITH LOW PRESSURE PASSING BY TO OUR WEST. THIS WILL CONTINUE
INTO MONDAY AS A COLD FRONT CROSSES THE REGION. AREAS OF IFR AND
LIFR TO RETURN ONCE AGAIN WEDNESDAY AND WEDNESDAY NIGHT WITH YET
ANOTHER AREA OF LOW PRESSURE PASSING BY WELL TO OUR WEST.
&&
.MARINE...
SHORT TERM...HAVE EXTENDED THE SCA FOR THE OCEAN WATERS THROUGH
MIDDAY SUNDAY BASED ON SEAS THAT ARE STILL EXPECTED TO BE AT OR
GREATER THAN 5 FT. OTHERWISE...ADDED CASCO BAY TO THE SCA FOR
TONIGHT ONLY AS FREQUENT GUSTS AROUND 25 KT ARE EXPECTED. A FEW
LOW-END GALE FORCE GUSTS POSSIBLE ON THE OCEAN WATERS TONIGHT.
CONDITIONS SUBSIDE SUNDAY.
LONG TERM...THE GRADIENT INCREASES SUNDAY NIGHT FROM THE
SOUTHWEST...ALLOWING WINDS TO INCREASE FROM THE SOUTHWEST INTO THE
SCA RANGE. GALE FORCE WINDS ARE POSSIBLE WEDNESDAY AS LOW PRESSURE
PASSES OVER THE GREAT LAKES AND INTO CANADA.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST SUNDAY
FOR ANZ151-153.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO NOON EST
SUNDAY FOR ANZ150-152-154.
&&
$$
NEAR TERM UPDATE...EKSTER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
910 AM CST SAT JAN 30 2016
.UPDATE...
ISSUED AT 856 AM CST SAT JAN 30 2016
FOR THE MORNING UPDATE WILL ADJUST POPS SOME OVER SOUTHWEST NORTH
DAKOTA. LATEST MESOSCALE MODELS LOOK TO BE VERIFYING A LITTLE TOO
FAR SOUTH WHEN COMPARED TO THE LATEST BOWMAN RADAR LOOP. HAVE
ADJUSTED POPS A LITTLE FARTHER NORTH AND UPPED POPS TO HIGHER
CHANCE. STILL PROBABLY PRETTY HARD FOR ANY ONE AREA TO GET
MEASURABLE PRECIP BUT THERE IS ENOUGH GROUND TRUTH WITH SNOW AT
BAKER...A MIX THEN SNOW AT DICKINSON...PLUS RETURNS ON RADAR...TO
JUSTIFY BUMPING UP POPS. MESOSCALE MODELS KEEP CHANCE OF PRECIP
AND EVEN SOME WEAK CAPE OVER THE SOUTHWEST THROUGH THE AFTERNOON
SO WILL LEAVE SMALL POPS AS PREVIOUSLY FORECAST THROUGH THE
AFTERNOON. OTHERWISE NO SIGNIFICANT UPDATES TO THE GOING FORECAST.
UPDATE ISSUED AT 635 AM CST SAT JAN 30 2016
NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE...THOUGH WE DID
PUSH LOW-END POPS A BIT FURTHER EAST INTO FAR SOUTH CENTRAL ND
TODAY BASED ON RECENT HRRR SIMULATIONS AND THE 06 UTC NAM. A MIX
OF RAIN AND SNOW REMAINS PRUDENT IN THE FORECAST IN PLACES WHERE
WE DO HAVE POPS GIVEN THERMAL PROFILES NEAR THE FREEZING MARK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SAT JAN 30 2016
THE MAIN FOCUS FOR THE SHORT TERM FORECAST IS PRECIPITATION
CHANCES ACROSS THE SOUTHWEST.
EARLY THIS MORNING A WEAK UPPER LEVEL SHORT WAVE TROUGH WAS
PUSHING ACROSS EASTERN MONTANA. THIS WILL PROVIDE THE ASCENT
NEEDED TO SPARK SOME LIGHT PRECIPITATION TODAY ACROSS THE
SOUTHWEST. BOWMAN RADAR CONTINUES TO INDICATE VERY LIGHT
PRECIPITATION IS POSSIBLE ACROSS THE SOUTHWEST. HOWEVER...NO
SURFACE OBSERVATIONS OR WEBCAMS HAVE RECORDED ANYTHING OF NOTE SO
FAR THIS MORNING. A MIX OF RAIN...FREEZING RAIN...SLEET AND SNOW
IS POSSIBLE WITH TEMPERATURES ALOFT WITHIN ONE OR TWO DEGREES OF
FREEZING AND SURFACE TEMPERATURES ALSO HOVERING AROUND FREEZING.
HOWEVER...SHORT TERM MODELS AND RADAR TRENDS INDICATE ONLY VERY
LIGHT AND SCATTERED PRECIPITATION MAY FALL...THEREFORE...NO MAJOR
IMPACTS ARE ANTICIPATED.
WITH WESTERLY WINDS AND NEARLY NEUTRAL TEMPERATURE ADVECTION
THROUGH MOST OF THE DAY...TEMPERATURES WILL LIKELY CLIMB BACK
INTO THE 40S ACROSS MOST OF THE SOUTH WEST AND SOUTH CENTRAL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CST SAT JAN 30 2016
SEASONABLY COLD WEATHER WILL PREVAIL DURING THE LONG TERM...WITH
ONLY A FEW LOW-GRADE OPPORTUNITIES OF LIGHT SNOW.
THE 00 UTC GLOBAL MODEL SUITE REMAINED IN GOOD AGREEMENT WITH ITS
DEPICTION OF NORTHWEST FLOW ALOFT DEVELOPING ACROSS THE REGION AS
A MEAN 500-MB TROUGH BECOMES ESTABLISHED OVER THE CENTRAL UNITED
STATES THIS WEEK. THIS WILL PROVIDE A RELATIVELY STEADY SUPPLY OF
COLD AIR ADVECTION TO THE NORTHERN PLAINS...ESPECIALLY AS LARGER-
SCALE FLOW AMPLIFIES IN RESPONSE TO WARM AIR ADVECTION AND HEIGHT
RISES ALOFT DOWNSTREAM OF THE POWERFUL STORM EXPECTED TO MOVE FROM
THE CENTRAL PLAINS TO THE GREAT LAKES BY MIDWEEK. A COOLING TREND
WILL RESULT WITH HIGHS FALLING FROM 25 TO 35 F SUNDAY TO 10 TO 25
F TUESDAY THROUGH FRIDAY /COLDEST IN NORTH CENTRAL ND/.
WELL-ESTABLISHED CYCLONIC FLOW IN THE EXPECTED WEATHER REGIME MAY
YIELD A LITTLE LIGHT SNOW ON SOME DAYS...ESPECIALLY WHEN EMBEDDED
VORTICITY MAXIMA TRAVERSE THE REGION. THE PREDICTABILITY OF THOSE
FEATURES IS GENERALLY LOW IN THIS PATTERN...BUT THE 00 UTC ECMWF
AND GFS BOTH SUGGESTED WEAK WAVES MAY CROSS THE AREA BOTH MONDAY
AND WEDNESDAY. OUR MODEL-BLEND-DRIVEN FORECAST THUS HAS LOW POPS
IN THOSE TIME PERIODS...MAINLY OVER WESTERN ND WHERE THE THERMAL
GRADIENT IN THE MIDDLE ATMOSPHERE WILL BE GREATEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 856 AM CST SAT JAN 30 2016
VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES. MVFR CONDITIONS ARE
POSSIBLE AT KDIK THIS MORNING...HOWEVER CONFIDENCE WAS NOT HIGH
ENOUGH TO MENTION IN THE TAF. A LIGHT MIX OF RAIN OR SNOW IS
POSSIBLE AT KDIK THIS MORNING BUT ONCE AGAIN CONFIDENCE IS NOT
VERY HIGH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...CJS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
635 AM CST SAT JAN 30 2016
.UPDATE...
ISSUED AT 635 AM CST SAT JAN 30 2016
NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE...THOUGH WE DID
PUSH LOW-END POPS A BIT FURTHER EAST INTO FAR SOUTH CENTRAL ND
TODAY BASED ON RECENT HRRR SIMULATIONS AND THE 06 UTC NAM. A MIX
OF RAIN AND SNOW REMAINS PRUDENT IN THE FORECAST IN PLACES WHERE
WE DO HAVE POPS GIVEN THERMAL PROFILES NEAR THE FREEZING MARK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SAT JAN 30 2016
THE MAIN FOCUS FOR THE SHORT TERM FORECAST IS PRECIPITATION
CHANCES ACROSS THE SOUTHWEST.
EARLY THIS MORNING A WEAK UPPER LEVEL SHORT WAVE TROUGH WAS
PUSHING ACROSS EASTERN MONTANA. THIS WILL PROVIDE THE ASCENT
NEEDED TO SPARK SOME LIGHT PRECIPITATION TODAY ACROSS THE
SOUTHWEST. BOWMAN RADAR CONTINUES TO INDICATE VERY LIGHT
PRECIPITATION IS POSSIBLE ACROSS THE SOUTHWEST. HOWEVER...NO
SURFACE OBSERVATIONS OR WEBCAMS HAVE RECORDED ANYTHING OF NOTE SO
FAR THIS MORNING. A MIX OF RAIN...FREEZING RAIN...SLEET AND SNOW
IS POSSIBLE WITH TEMPERATURES ALOFT WITHIN ONE OR TWO DEGREES OF
FREEZING AND SURFACE TEMPERATURES ALSO HOVERING AROUND FREEZING.
HOWEVER...SHORT TERM MODELS AND RADAR TRENDS INDICATE ONLY VERY
LIGHT AND SCATTERED PRECIPITATION MAY FALL...THEREFORE...NO MAJOR
IMPACTS ARE ANTICIPATED.
WITH WESTERLY WINDS AND NEARLY NEUTRAL TEMPERATURE ADVECTION
THROUGH MOST OF THE DAY...TEMPERATURES WILL LIKELY CLIMB BACK
INTO THE 40S ACROSS MOST OF THE SOUTH WEST AND SOUTH CENTRAL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CST SAT JAN 30 2016
SEASONABLY COLD WEATHER WILL PREVAIL DURING THE LONG TERM...WITH
ONLY A FEW LOW-GRADE OPPORTUNITIES OF LIGHT SNOW.
THE 00 UTC GLOBAL MODEL SUITE REMAINED IN GOOD AGREEMENT WITH ITS
DEPICTION OF NORTHWEST FLOW ALOFT DEVELOPING ACROSS THE REGION AS
A MEAN 500-MB TROUGH BECOMES ESTABLISHED OVER THE CENTRAL UNITED
STATES THIS WEEK. THIS WILL PROVIDE A RELATIVELY STEADY SUPPLY OF
COLD AIR ADVECTION TO THE NORTHERN PLAINS...ESPECIALLY AS LARGER-
SCALE FLOW AMPLIFIES IN RESPONSE TO WARM AIR ADVECTION AND HEIGHT
RISES ALOFT DOWNSTREAM OF THE POWERFUL STORM EXPECTED TO MOVE FROM
THE CENTRAL PLAINS TO THE GREAT LAKES BY MIDWEEK. A COOLING TREND
WILL RESULT WITH HIGHS FALLING FROM 25 TO 35 F SUNDAY TO 10 TO 25
F TUESDAY THROUGH FRIDAY /COLDEST IN NORTH CENTRAL ND/.
WELL-ESTABLISHED CYCLONIC FLOW IN THE EXPECTED WEATHER REGIME MAY
YIELD A LITTLE LIGHT SNOW ON SOME DAYS...ESPECIALLY WHEN EMBEDDED
VORTICITY MAXIMA TRAVERSE THE REGION. THE PREDICTABILITY OF THOSE
FEATURES IS GENERALLY LOW IN THIS PATTERN...BUT THE 00 UTC ECMWF
AND GFS BOTH SUGGESTED WEAK WAVES MAY CROSS THE AREA BOTH MONDAY
AND WEDNESDAY. OUR MODEL-BLEND-DRIVEN FORECAST THUS HAS LOW POPS
IN THOSE TIME PERIODS...MAINLY OVER WESTERN ND WHERE THE THERMAL
GRADIENT IN THE MIDDLE ATMOSPHERE WILL BE GREATEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 635 AM CST SAT JAN 30 2016
VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES. MVFR CONDITIONS ARE
POSSIBLE AT KDIK THIS MORNING...HOWEVER CONFIDENCE WAS NOT HIGH
ENOUGH TO MENTION IN THE TAF. A LIGHT MIX OF RAIN OR SNOW IS
POSSIBLE AT KDIK/KISN THIS MORNING BUT ONCE AGAIN CONFIDENCE IS
NOT VERY HIGH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...AJ
LONG TERM...CJS
AVIATION...AJ
Area Forecast Discussion
National Weather Service Spokane WA
354 AM PST SAT JAN 30 2016
.SYNOPSIS...
An upper level trough will settle over the region today and
linger through Monday. This will result in seasonal temperatures
with a chance of snow showers. Expect a short dry period through
mid-week then a more organized system approach again toward next
Thursday.
&&
.DISCUSSION...
Today through Sunday night...The ridge of high pressure has been
replaced by a long wave trough over the region. This will put the
region into more of a westerly flow and effectively cut the region
off from the deep Pacific moisture tap that has been over the
Pacific Northwest for most of the week. But that doesn`t mean
conditions will be totally dry. The cold core will track across
the forecast area today. This will destabilize the atmosphere. In
addition model guidance has been pretty consistent showing a
series of weak short wave disturbances moving through the area
today through Sunday. Enough moisture will linger for scattered
rain and snow showers both days. The best chance for showers will
be on the lee side of the Cascades and of course in the
orographically favored Panhandle mountains and the Blue mountains.
However, in this type of a pattern just about anywhere could pop
an intense, short lived shower. Precipitation would be mainly as
snow with rain/snow mix for the lower elevations and possibly some
graupel. The NAM and HRRR models have been picking up on a
particularly robust wave this morning across the southeast zones,
from the Camas Prairie north to around Pullman and Avery. As such
pops were bumped up in this area. A fast couple of inches of
snowfall could be possible with these showers. Pretty tough to
pinpoint just exactly where these will form so no highlights are
expected and we will handle this with Nowcasts and social media as
best we can. Temperatures should be within a degree or two of
seasonal normals. Southwest winds across the southeast zones will
remain slightly elevated today with sustained winds 10-15 mph and
gusts around 25 mph through most of the day.
The upper level trough will shift east Saturday night through
Monday as a high amplitude ridge tracks from about 150W to near
the coast. This will shift the flow into an even drier northwest-
north flow. Isolated to scattered showers will linger near the
Cascade crest, the northeast mountains with light snow
accumulations at times. Northwest-northerly flow supports a better
chance for showers for the Panhandle mountains and this is an
excellent set up for the Blues and Camas Prairie. While showers
will remain in the forecast, we expect less moisture to work with
and the train of weak disturbances will get cut-off. I wouldn`t be
surprised if a few spots pick up an inch or two of snow. But this
will be isolated and widely scattered. Tobin
Monday through Tuesday night...Shortwave energy will continue to
keep a chance of snow showers across the forecast area through
Tuesday but mainly confined to the Cascade crest and the eastern
third of the forecast area. The northerly overland trajectory will
keep any snowfall accumulations rather light. By Tuesday night the
offshore ridge axis will start to migrate east. This will relegate
any lingering precipitation to the Idaho panhandle. Daytime
temperatures will be in the 30s with low 40s for the southernmost
valleys. Overnight lows will be on a cooling trend as northerly flow
keeps bringing colder air in from the north.
Wednesday through Friday...The east Pacific ridge will be pushed
inland by an approaching trough of low pressure. The mainly dry
weather pattern for Wednesday will become more unsettled as the
trough moves through the Inland Northwest Thursday. As warmer air
aloft pushes into the region from the south Thursday morning there
is a threat of freezing rain for the lower basin and possibly into
the Wenatchee area as well. Thursday looks like the best bet for
some light to moderate snowfall accumulations for much of the
forecast area. Beyond Thursday, model solutions diverge with the
ECMWF allowing the ridge to quickly build back over the region while
the GFS keeps a more unsettled trough pattern over us. /Kelch
&&
.AVIATION...
12Z TAFS: An upper level trough has moved into the area overnight
and will linger through at least Sunday. This will allow the
atmosphere to destabilize and support snow showers across the
region...mainly though the afternoon and early evening. A slightly
stronger wave looks to move through the southeast zones and
may increase the intensity of the showers near KLWS/KPUW through
00z this afternoon. Otherwise showers will be isolated to
scattered. Southwest winds and lingering boundary level moisture
will allow stratus formation for the KCOE/KSFF/KGEG corridor with
conditions MVFR/IFR. Near KPUW/KLWS VFR/MVFR conditions for
localized stratus and the potential for heavier showers. Lastly
the southwest winds have backed off from yesterday...but still
expect winds 10-15 kts with gusts 20-25kts for KPUW and KGEG.
Tobin
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 27 34 26 34 24 / 20 20 20 20 20 20
Coeur d`Alene 35 27 34 27 33 26 / 30 30 40 20 20 40
Pullman 38 28 35 28 34 26 / 60 20 40 20 40 30
Lewiston 44 32 42 31 39 30 / 60 20 20 20 40 20
Colville 34 27 33 26 33 23 / 20 20 20 20 10 30
Sandpoint 34 28 33 27 32 27 / 30 30 40 30 20 40
Kellogg 33 27 31 25 31 24 / 70 40 50 30 50 50
Moses Lake 41 27 38 26 37 25 / 10 10 10 10 10 10
Wenatchee 38 29 36 27 36 27 / 10 10 10 10 10 10
Omak 34 25 32 22 32 21 / 10 20 20 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
305 AM PST SAT JAN 30 2016
.SYNOPSIS...COOL AND SOMEWHAT UNSTABLE ONSHORE FLOW WILL CONTINUE TO
SPREAD SHOWERS WITH SNOW IN THE MOUNTAINS ACROSS SOUTHWEST WASHINGTON
AND NORTHWEST OREGON...WITH A FEW THUNDERSTORMS NEAR THE COAST
SPREADING INLAND IN THE AFTERNOONS AND EARLY EVENINGS.
THE SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE
WEEKEND...THOUGH THE ONSHORE FLOW WILL WEAKEN SOME LATER SATURDAY
THROUGH SUNDAY. SNOW LEVELS WILL FALL TO BETWEEN 1500 AND 2500 FEET
THIS WEEKEND...POSSIBLY A LITTLE LOWER IN ANY HEAVIER SHOWERS. WHILE
THE LOW LEVEL FLOW WILL BECOME MORE NORTHWESTERLY EARLY NEXT
WEEK...SOME COOL SHOWERS WILL CONTINUE AS WEAK DISTURBANCES MOVE
THROUGH MONDAY AND TUESDAY. THE NEXT ORGANIZED FRONT IS EXPECTED
AROUND THURSDAY OF NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY...SHOWERS CONTINUE TO STREAM
ACROSS THE AREA THIS MORNING WITH THE SNOW LEVEL DOWN TO AROUND
2000-2500 FEET. INFRARED SATELLITE SHOWS A LARGE AREA OF COLD AIR
CUMULUS EXTENDING WEST OF THE WA/OR COAST. THIS WILL BE THE SOURCE OF
THE SHOWERS THROUGH THE WEEKEND. EMBEDDED SHORTWAVES WILL ENHANCE
SHOWER ACTIVITY THIS AFTERNOON AND EVENING ESPECIALLY OVER THE
NORTHERN ZONES. THE AIR MASS IS UNSTABLE ENOUGH FOR SOME ISOLATED
THUNDERSTORMS OVER THE WATERS THIS WEEKEND. THUNDERSTORMS MAY ALSO
EXTEND INLAND WITH DAYTIME INSOLATION TODAY AND SUNDAY.
CASCADES WILL SEE DECENT SNOW ACCUMULATIONS IN THE CASCADES TODAY
AS SNOW LEVELS LOWER TO AROUND 1500 TO 2000 FEET. THE ONSHORE FLOW
EASES SOME THIS AFTERNOON AND TONIGHT SO SNOWFALL RATES WILL DECREASE
AS WELL. SNOW SHOWERS WILL CONTINUE INTO SUNDAY BUT ACCUMULATIONS
ARE EXPECTED TO REMAIN BELOW ADVISORY CRITERIA. WITH THE LOW SNOW
LEVELS THE COAST RANGE AND CASCADE FOOTHILLS WILL ALSO SEE SOME SNOW.
HIGHER PASSES CROSSING THE COAST RANGE MAY SEE LIGHT ACCUMULATIONS
TONIGHT AND SUNDAY.
THERE IS STILL A CHANCE OF SHOWERS WITH SNOW IN THE MOUNTAINS MONDAY
UNDER NORTHWESTERLY FLOW ALOFT AND AT LOW LEVELS. SNOW LEVELS WILL
REMAIN AROUND 1500 FT. /MH
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MONDAY NIGHT THROUGH FRIDAY...A WEAK SHORTWAVE TROUGH LOOKS TO
QUICKLY MOVE ACROSS THE PAC NW TUESDAY MAINTAINING OUR SHOWERY
PATTERN. SNOW LEVELS WILL HOVER AROUND 2000 FT SO SOME LIGHT
ACCUMULATIONS IN THE CASCADES...FOOTHILLS...AND COAST RANGE APPEAR
LIKELY. UPPER LEVEL RIDGING LOOKS TO MOVE INTO THE REGION LATE
TUESDAY AND COULD BRING A BRIEF PERIOD OF DRY WEATHER THROUGH
WEDNESDAY SO HAVE LOWERED POPS ACROSS THE FORECAST AREA TO AROUND 20
PERCENT OR LESS. MODELS CONTINUE TO SHOW A FRONT APPROACHING THE
COAST NEXT WEEK BUT HAVE SLOWED IT DOWN A BIT. THE FRONT IS NOW
EXPECTED TO MOVE ACROSS THE REGION THURSDAY...WITH SNOW LEVELS
RISING TO AROUND 4000 FT LATE THURSDAY. UPPER LEVEL RIDGING LOOKS TO
BUILD BEHIND THE FRONT LATE THURSDAY AND COULD GIVE US A FEW DAYS OF
DRY WEATHER LATE NEXT WEEK. EXPECT SEASONAL TEMPS THROUGH THE
FORECAST PERIOD. /64
&&
.AVIATION...OVER THE NEXT 24 HOURS WEATHER PATTERN STAYS PRETTY
MUCH THE SAME. UNSTABLE ONSHORE FLOW WILL CONTINUE TO BRING
SCATTERED SHOWERS AND KEEP CONDITIONS AT TERMINALS PREDOMINANTLY
VFR. OCCASIONALLY CIGS AND VIS WILL DROP TO MVFR WITH HEAVIER
SHOWERS. CHANCE OF THUNDERSTORMS OVER THE INTERIOR SATURDAY MID-
DAY WITH SMALL HAIL POSSIBLE. CONFIDENCE IN TIMING OR LOCATION OF
THUNDERSTORMS IS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS.
KPDX AND APPROACHES...SCATTERED SHOWERS FOR NEXT 24 HRS.
PREDOMINANTLY VFR CONDITIONS WITH CIGS AND VIS OCCASIONALLY
DROPPING TO MVFR IN HEAVIER SHOWERS. THUNDER POSSIBLE AROUND
MIDDAY SATURDAY. BOWEN
&&
.MARINE...WINDS REMAIN JUST ABOVE 20 KT SO WILL LET THE SMALL
CRAFT ADVISORY FOR WINDS RUN ITS COURSE THROUGH 12Z. WINDS
GENERALLY COMING DOWN THOUGH...SO DO NOT THINK IT WILL NEED TO BE
EXTENDED. ONCE WINDS DROP BELOW 20 KT...SHOULD STAY DOWN UNTIL AT
LEAST EARLY SUNDAY MORNING. HOWEVER ISOLATED THUNDERSTORMS ARE
POSSIBLE TONIGHT THROUGH SUNDAY...WHICH COULD PRODUCE INFREQUENT
WIND GUSTS UP TO 30 KT.
MUCH UNCERTAINTY STILL WITH THE LOW PRESSURE SYSTEM ON SUNDAY.
THOUGH IT WILL BE RELATIVELY WEAK...THERE IS THE POSSIBILITY THAT
IT COULD CAUSE GUSTY WINDS ACROSS THE LOCAL WATERS. WORST CASE IT
WILL BRING WINDS GUSTING TO 25 TO 30 KT SUNDAY MID-DAY OR EVENING
OUT OF THE NORTHWEST. IF THE CIRCULATION MOVES INLAND TO OUR
NORTH...WINDS SHOULD STAY BELOW 20 KT ALL DAY SUNDAY. HIGH
PRESSURE BUILDS OVER THE WATERS EARLY NEXT WEEK FOR GENERALLY
BENIGN CONDITIONS WITH SEAS FALLING BELOW 10 FT LATE MONDAY.
BEYOND THAT...THE NEXT SYSTEM ISN`T UNTIL A STRONGER FRONTAL
SYSTEM APPROACHES OUR WATERS LATE WEDNESDAY INTO THURSDAY. BOWEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR
CASCADES IN LANE COUNTY-NORTHERN OREGON CASCADES.
WA...WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST EARLY THIS
MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST SUNDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
MIDNIGHT PST TONIGHT.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
229 AM PST SAT JAN 30 2016
.SYNOPSIS...
An upper level trough will settle over the region today and
linger through Monday. This will result in seasonal temperatures
with a chance of snow showers. Expect a short dry period through
mid-week then a more organized system approach again toward next
Thursday.
&&
.DISCUSSION...
Today through Sunday night...The ridge of high pressure has been
replaced by a long wave trough over the region. This will put the
region into more of a westerly flow and effectively cut the region
off from the deep Pacific moisture tap that has been over the
Pacific Northwest for most of the week. But that doesn`t mean
conditions will be totally dry. The cold core will track across
the forecast area today. This will destabilize the atmosphere. In
addition model guidance has been pretty consistent showing a
series of weak short wave disturbances moving through the area
today through Sunday. Enough moisture will linger for scattered
rain and snow showers both days. The best chance for showers will
be on the lee side of the Cascades and of course in the
orographically favored Panhandle mountains and the Blue mountains.
However, in this type of a pattern just about anywhere could pop
an intense, short lived shower. Precipitation would be mainly as
snow with rain/snow mix for the lower elevations and possibly some
graupel. The NAM and HRRR models have been picking up on a
particularly robust wave this morning across the southeast zones,
from the Camas Prairie north to around Pullman and Avery. As such
pops were bumped up in this area. A fast couple of inches of
snowfall could be possible with these showers. Pretty tough to
pinpoint just exactly where these will form so no highlights are
expected and we will handle this with Nowcasts and social media as
best we can. Temperatures should be within a degree or two of
seasonal normals. Southwest winds across the southeast zones will
remain slightly elevated today with sustained winds 10-15 mph and
gusts around 25 mph through most of the day.
The upper level trough will shift east Saturday night through
Monday as a high amplitude ridge tracks from about 150W to near
the coast. This will shift the flow into an even drier northwest-
north flow. Isolated to scattered showers will linger near the
Cascade crest, the northeast mountains with light snow
accumulations at times. Northwest-northerly flow supports a better
chance for showers for the Panhandle mountains and this is an
excellent set up for the Blues and Camas Prairie. While showers
will remain in the forecast, we expect less moisture to work with
and the train of weak disturbances will get cut-off. I wouldn`t be
surprised if a few spots pick up an inch or two of snow. But this
will be isolated and widely scattered. Tobin
Monday through Tuesday night...Shortwave energy will continue to
keep a chance of snow showers across the forecast area through
Tuesday but mainly confined to the Cascade crest and the eastern
third of the forecast area. The northerly overland trajectory will
keep any snowfall accumulations rather light. By Tuesday night the
offshore ridge axis will start to migrate east. This will relegate
any lingering precipitation to the Idaho panhandle. Daytime
temperatures will be in the 30s with low 40s for the southernmost
valleys. Overnight lows will be on a cooling trend as northerly flow
keeps bringing colder air in from the north.
Wednesday through Friday...The east Pacific ridge will be pushed
inland by an approaching trough of low pressure. The mainly dry
weather pattern for Wednesday will become more unsettled as the
trough moves through the Inland Northwest Thursday. As warmer air
aloft pushes into the region from the south Thursday morning there
is a threat of freezing rain for the lower basin and possibly into
the Wenatchee area as well. Thursday looks like the best bet for
some light to moderate snowfall accumulations for much of the
forecast area. Beyond Thursday, model solutions diverge with the
ECMWF allowing the ridge to quickly build back over the region while
the GFS keeps a more unsettled trough pattern over us. /Kelch
&&
.AVIATION...
06Z TAFS: Winds have decreased across most of the region. Expect
some stratus to develop btwn 08-10Z for eastern TAF sites. Latest
NAM and HRRR is showing some -shsn developing aft 10Z for eastern
TAF locations. HRRR has been waffling a bit btwn runs, but have
kept it in the TAF. More confident about KPUW than other sites.
The -shsn potential ends btwn 15 and 18Z with clouds generally
lifting and decreasing through the afternoon. The potential exists
for stratus to set up in the Columbia Basin and Wenatchee area as
well. Am more confident about KEAT than KMWH. The stratus will
linger around through the morning and then break up in the aftn.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 27 34 26 34 24 / 20 20 20 20 20 20
Coeur d`Alene 35 27 34 27 33 26 / 30 30 40 20 20 40
Pullman 38 28 35 28 34 26 / 60 20 40 20 40 30
Lewiston 44 32 42 31 39 30 / 60 20 20 20 40 20
Colville 34 27 33 26 33 23 / 20 20 20 20 10 30
Sandpoint 34 28 33 27 32 27 / 30 30 40 30 20 40
Kellogg 33 27 31 25 31 24 / 70 40 50 30 50 50
Moses Lake 41 27 38 26 37 25 / 10 10 10 10 10 10
Wenatchee 38 29 36 27 36 27 / 10 10 10 10 10 10
Omak 34 25 32 22 32 21 / 10 20 20 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1041 AM PST SAT JAN 30 2016
.SYNOPSIS...LIGHT RAINFALL IS EXPECTED TO TAPER OFF TODAY AS THE
TAIL END OF A SYSTEM MOVES TO THE EAST. THE NEXT SYSTEM WILL
SPREAD RAIN ACROSS THE SOUTHERN HALF OF THE FORECAST AREA ON
SUNDAY...WITH LOCALLY HEAVY RAIN POSSIBLE ALONG THE BIG SUR COAST
AND IN THE SANTA LUCIA MOUNTAINS. BEHIND THE SUNDAY
SYSTEM...BREEZY CONDITIONS ARE EXPECTED LATE SUNDAY AFTERNOON
THROUGH SUNDAY NIGHT...MAINLY NEAR THE COAST. DRY WEATHER RETURNS
MONDAY AND CONTINUES FOR MUCH OF NEXT WEEK.
&&
.DISCUSSION...AS OF 09:01 AM PST SATURDAY...EQUIPMENT UPDATE -
THE KMUX RADAR REMAINS OUT OF SERVICE...AWAITING PARTS TO REPAIR
IT. EARLIEST IT COULD BE REPAIRED WOULD BE THIS AFTERNOON. FOR
RADAR COVERAGE PLEASE USE KDAX TO THE EAST OR KBHX TO THE NORTH.
SHORT TERM CONCERNS CONTINUE TO BE SOME LINGERING SHOWERS THIS
MORNING. LATEST SFC OBS CONTINUE TO INDICATE A FEW TIPS HERE AND
THERE...IN OTHER WORDS WIDELY SCATTERED. IMPACT WILL BE MINIMAL
AS RAINFALL AMOUNTS WILL BE A FEW HUNDREDTHS AT BEST. BY THIS
AFTERNOON...CHANCES FOR PRECIP WILL BE EVEN LESS. CURRENT FORECAST
HAS A WIDESPREAD 15 PCT AND SLIGHT CHANCE FOR SHOWERS. THIS STILL
SEEMS PLAUSIBLE GIVEN THE HRRR AND WRF MODELS SHOW WIDELY
SCATTERED SHOWERS THIS AFTERNOON. LOOKING UPSTREAM...THERE ARE
CURRENTLY SCATTERED SHOWERS WELL NORTH OF THE NORTH BAY SLOWLY
MOVING SOUTH. NO UPDATE IS PLANNED AT THIS TIME.
NEXT WEATHER CONCERN WILL BE THE UPPER LOW DROPPING SOUTH THROUGH
CALIFORNIA. SEVERAL DAYS/RUNS AGO THIS SYSTEM LOOKED VERY
ROBUST...BUT LATEST TRENDS HAVE BEEN LESS FOR THE MTR CWA. THE
BIGGEST IMPACTS WITH RAIN AND WINDS WILL APPEARS TO BE SOUTH OF
THE CWA. HOWEVER...RAIN AND WIND WILL STILL BE POSSIBLE...BUT
MAINLY SOUTH OF MONTEREY BAY. WILL FINE TUNE THIS WITH THE
AFTERNOON FORECAST PACKAGE.
&&
.PREV DISCUSSION...AS OF 3:25 AM PST SATURDAY...
THE NEXT SYSTEM IS FORECAST TO AFFECT THE SOUTHERN PORTION OF OUR
CWA ON SUNDAY AND SUNDAY NIGHT AS AN UPPER LEVEL TROUGH MOVES
ACROSS. LATEST MODEL GUIDANCE...THOUGH...IS INDICATING THAT THE
HEAVIEST RAINFALL WILL OCCUR SOUTH OF OUR AREA. GIVEN EARLIER
UNCERTAINTY...CANNOT COMPLETELY RULE OUT THE POSSIBILITY OF
LOCALLY HEAVY RAINS ALONG THE BIG SUR COAST ON SUNDAY.
RAINFALL WILL END IN MOST AREAS BY LATE SUNDAY AFTERNOON.
BREEZY CONDITIONS ARE EXPECTED TO DEVELOP BY LATE SUNDAY AS A
SURFACE LOW DEVELOPS NEAR LAS VEGAS AND SURFACE HIGH BUILDS
OFFSHORE. THE GRADIENT BETWEEN THE TWO WILL DRIVE BRISK NORTHWEST
WINDS ACROSS THE AREA LATE SUNDAY AND SUNDAY NIGHT. STRONGEST
WINDS ARE EXPECTED TO OCCUR ALONG THE COAST. AT THIS TIME A WIND
ADVISORY DOES NOT SEEM NECESSARY...HOWEVER...THIS COULD CHANGE.
COOLER TEMPERATURES ARE EXPECTED EARLY NEXT WEEK AS A COOLER
AIRMASS SETTLES IN. BY MONDAY NIGHT OVERNIGHT TEMPERATURES ARE
EXPECTED TO DIP DOWN INTO THE 30S IN INLAND VALLEYS. HIGHS WILL
ALSO BE COOL THROUGH MIDWEEK WITH HIGH TEMPS IN THE LOWER 50S. THE
LONGER RANGE MODELS AGREE THAT MOST OF NEXT WEEK WILL BE DRY WITH
PERHAPS JUST A COUPLE OF BRIEF LIGHT RAIN EVENTS.
&&
.AVIATION...AS OF 10:15 AM PST SATURDAY...SKIES ARE QUICKLY
SCATTERING OUT THIS MORNING OVER THE NORTHERN HALF OF THE FORECAST
AREA. SCATTERED HIGH CLOUDS WILL PERSIST ACROSS THE REGION THROUGH
MUCH OF THE FORECAST PERIOD. MODERATE CONFIDENCE.
VICINITY OF KSFO...VFR CONDITIONS ARE EXPECTED TODAY. WESTERLY
WINDS 10 TO 15 KT WILL PREVAIL TODAY.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS ARE EXPECTED TODAY.
WESTERLY WINDS AROUND 10 KT WILL PREVAIL TODAY.
&&
.MARINE...AS OF 10:26 AM PST SATURDAY...NORTHERLY WINDS ARE
FILLING IN BEHIND A COLD FRONT THIS MORNING. MODERATE BREAKING
WAVES WILL REMAIN A POSSIBILITY ALONG THE COAST TODAY BUT SEAS ARE
ANTICIPATED TO DECREASE THIS AFTERNOON. THE SURFACE PRESSURE
GRADIENT IS EXPECTED TO STRENGTHEN ON SUNDAY BRINGING INCREASING
NORTHERLY WINDS AND DETERIORATING SEA CONDITIONS TO THE COASTAL
WATERS BEGINNING SUNDAY AFTERNOON.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: MM
AVIATION: CW
MARINE: GARCIA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
901 AM PST SAT JAN 30 2016
.SYNOPSIS...LIGHT RAINFALL IS EXPECTED TO TAPER OFF TODAY AS THE
TAIL END OF A SYSTEM MOVES TO THE EAST. THE NEXT SYSTEM WILL
SPREAD RAIN ACROSS THE SOUTHERN HALF OF THE FORECAST AREA ON
SUNDAY...WITH LOCALLY HEAVY RAIN POSSIBLE ALONG THE BIG SUR COAST
AND IN THE SANTA LUCIA MOUNTAINS. BEHIND THE SUNDAY
SYSTEM...BREEZY CONDITIONS ARE EXPECTED LATE SUNDAY AFTERNOON
THROUGH SUNDAY NIGHT...MAINLY NEAR THE COAST. DRY WEATHER RETURNS
MONDAY AND CONTINUES FOR MUCH OF NEXT WEEK.
&&
.DISCUSSION...AS OF 09:01 AM PST SATURDAY...EQUIPMENT UPDATE -
THE KMUX RADAR REMAINS OUT OF SERVICE...AWAITING PARTS TO REPAIR
IT. EARLIEST IT COULD BE REPAIRED WOULD BE THIS AFTERNOON. FOR
RADAR COVERAGE PLEASE USE KDAX TO THE EAST OR KBHX TO THE NORTH.
SHORT TERM CONCERNS CONTINUE TO BE SOME LINGERING SHOWERS THIS
MORNING. LATEST SFC OBS CONTINUE TO INDICATE A FEW TIPS HERE AND
THERE...IN OTHER WORDS WIDELY SCATTERED. IMPACT WILL BE MINIMAL
AS RAINFALL AMOUNTS WILL BE A FEW HUNDREDTHS AT BEST. BY THIS
AFTERNOON...CHANCES FOR PRECIP WILL BE EVEN LESS. CURRENT FORECAST
HAS A WIDESPREAD 15 PCT AND SLIGHT CHANCE FOR SHOWERS. THIS STILL
SEEMS PLAUSIBLE GIVEN THE HRRR AND WRF MODELS SHOW WIDELY
SCATTERED SHOWERS THIS AFTERNOON. LOOKING UPSTREAM...THERE ARE
CURRENTLY SCATTERED SHOWERS WELL NORTH OF THE NORTH BAY SLOWLY
MOVING SOUTH. NO UPDATE IS PLANNED AT THIS TIME.
NEXT WEATHER CONCERN WILL BE THE UPPER LOW DROPPING SOUTH THROUGH
CALIFORNIA. SEVERAL DAYS/RUNS AGO THIS SYSTEM LOOKED VERY
ROBUST...BUT LATEST TRENDS HAVE BEEN LESS FOR THE MTR CWA. THE
BIGGEST IMPACTS WITH RAIN AND WINDS WILL APPEARS TO BE SOUTH OF
THE CWA. HOWEVER...RAIN AND WIND WILL STILL BE POSSIBLE...BUT
MAINLY SOUTH OF MONTEREY BAY. WILL FINE TUNE THIS WITH THE
AFTERNOON FORECAST PACKAGE.
&&
.PREV DISCUSSION...AS OF 3:25 AM PST SATURDAY...
THE NEXT SYSTEM IS FORECAST TO AFFECT THE SOUTHERN PORTION OF OUR
CWA ON SUNDAY AND SUNDAY NIGHT AS AN UPPER LEVEL TROUGH MOVES
ACROSS. LATEST MODEL GUIDANCE...THOUGH...IS INDICATING THAT THE
HEAVIEST RAINFALL WILL OCCUR SOUTH OF OUR AREA. GIVEN EARLIER
UNCERTAINTY...CANNOT COMPLETELY RULE OUT THE POSSIBILITY OF
LOCALLY HEAVY RAINS ALONG THE BIG SUR COAST ON SUNDAY.
RAINFALL WILL END IN MOST AREAS BY LATE SUNDAY AFTERNOON.
BREEZY CONDITIONS ARE EXPECTED TO DEVELOP BY LATE SUNDAY AS A
SURFACE LOW DEVELOPS NEAR LAS VEGAS AND SURFACE HIGH BUILDS
OFFSHORE. THE GRADIENT BETWEEN THE TWO WILL DRIVE BRISK NORTHWEST
WINDS ACROSS THE AREA LATE SUNDAY AND SUNDAY NIGHT. STRONGEST
WINDS ARE EXPECTED TO OCCUR ALONG THE COAST. AT THIS TIME A WIND
ADVISORY DOES NOT SEEM NECESSARY...HOWEVER...THIS COULD CHANGE.
COOLER TEMPERATURES ARE EXPECTED EARLY NEXT WEEK AS A COOLER
AIRMASS SETTLES IN. BY MONDAY NIGHT OVERNIGHT TEMPERATURES ARE
EXPECTED TO DIP DOWN INTO THE 30S IN INLAND VALLEYS. HIGHS WILL
ALSO BE COOL THROUGH MIDWEEK WITH HIGH TEMPS IN THE LOWER 50S. THE
LONGER RANGE MODELS AGREE THAT MOST OF NEXT WEEK WILL BE DRY WITH
PERHAPS JUST A COUPLE OF BRIEF LIGHT RAIN EVENTS.
&&
.AVIATION...AS OF 3:58 AM PST SATURDAY...THE CURRENT IR SATELLITE
IMAGE CONTINUES TO SHOW THE REMNANTS OF A DEPARTING COLD FRONT
PASSING OVER THE FORECAST AREA THIS MORNING. THE FRONT HAS PASSED
SOUTH OF SAN FRANCISCO AND IS STILL PROMOTING SHOWERS IN THE
MONTEREY BAY AREA. SHOWERS SHOULD COME TO AN END AROUND SUN RISE.
VICINITY OF KSFO...VFR CONDITIONS ARE EXPECTED TODAY WITH CIGS
OVC035-040. WESTERLY WINDS 10 TO 15 KT WILL PREVAIL TODAY.
CONFIDENCE IS MODERATE.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...LIFR CONDITIONS WITH LIGHT RAIN WILL
PREVAIL THROUGH AROUND 1500Z AT WHICH POINT RAIN IS ANTICIPATED
TO END AND CIGS ARE ANTICIPATED TO IMPROVE TO IFR. VFR IS EXPECTED
BY LATE MORNING.
CONFIDENCE IS MODERATE.
&&
.MARINE...AS OF 2:58 AM PST SATURDAY...NORTHERLY WINDS ARE
FILLING IN BEHIND A COLD FRONT WHICH IS NOW PASSING OVER THE
SOUTHERN WATERS. MODERATE BREAKING WAVES WILL REMAIN A POSSIBILITY
ALONG THE COAST TODAY BUT SEAS ARE ANTICIPATED TO DECREASE THIS
AFTERNOON. THE SURFACE PRESSURE GRADIENT IS EXPECTED TO STRENGTHEN
ON SUNDAY BRINGING INCREASING NORTHERLY WINDS AND DETERIORATING
SEA CONDITIONS TO THE COASTAL WATERS BEGINNING SUNDAY AFTERNOON.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: MM
AVIATION: LARRY
MARINE: LARRY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 PM EST SAT JAN 30 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 346 PM EST SAT JAN 30 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MAINLY ZONAL MID/UPPER LEVEL
PATTERN ACROSS THE CONUS. A WEAK UPSTREAM SHORTAVE TROUGH WAS MOVING
INTO THE NRN PLAINS. AT THE SFC...A 984 MB LOW WAS MOVING THROUGH
NRN ONTARIO TOWAD JAMES BAY RESULTING IN SW TO W FLOW OR MILD
PACIFIC AIR INTO THE REGION. TEMPS HAVE CLIMBED TO NEAR OR ABOVE
RECORD VALUES WITH 44F AT THE NWS OFFICE BREAKING THE OLD RECORD OF
41. VIS LOOP SHOWED MOSTLY CLEAR SKIES OVER MOST OF UPPER MI WITH
MID/HIGH CLOUDS GRADUALLY SPREADING INTO THE SOUTH.
TONIGHT INTO SUN...MILD CONDITIONS WILL PREVAIL AS A WEAK TROUGH
INTO CNTRL MN MOVES INTO THE REGION. A BAND OF 800-600 MB FGEN
ASSOCIATED WITH A JET STREAK LIFTING NE FROM THE NRN LAKES WILL HELP
SUPPORT AN AREA OF PCPN FROM CNTRL INTO NE WI AND INTO FAR SRN AND
POSSIBLY SE UPPER MI. MODELS CONSENSUS SUGGESTS THAT QPF AMOUNTS TO
AROUND 0.10 INCH FROM 06Z-18Z MAY AFFECT LOCATIONS NEAR MNM.
HOWEVER...GIVEN THE MODELS SPREAD...CONFIDENCE IS MARGINAL AND MAINLY
CHNANCE POPS WERE MENTIONED EXCEPT AT MNM (60 POP) AROUND 12Z. LOW
LEVEL TEMP PROFILES SUPPORT MAINLY RAIN AS THE PCPN TYPE.
HOWEVER...WITH TEMPS FALLING TO NEAR 32F A BIT FARTHER INLAND...SOME
FZRA/SN MAY ALSO MIX WITH THE PCPN. SO...EVEN THOUGH LITTLE OR NO
ICE/SNOW ACCUMULATIONS ARE EXPECTED ANY SMALL AMOUNTS ON UNTREATED
SURFACES COULD STILL CREATE HAZARDOUS CONDITIONS. AS THE DEEPER
MOISTURE MOVES OUT IN THE MORNING...AND LOW LEVEL MOISTURE LINGERS
ALONG THE TROUGH/FRONT...SOME DZ/FZDZ WILL BE POSSIBLE OVER THE SE
HALF. TEMPS WILL REMAIN WELL ABOVE NORMAL WITH HIGHS FROM THE LOWER
30S OVER THE NW HALF TO THE MID AND UPPER 30S OVER THE S AND E.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 415 PM EST SAT JAN 30 2016
...WINTER STORM LATE TUESDAY INTO WEDNESDAY IS STILL ON...
SPLIT FLOW PATTERN ALOFT HAS RE-ORGANIZED THE LAST DAY WITH STRONG
JET ACROSS PACIFIC SPLITTING ALONG WEST COAST. STRONGEST JET ENERGY
IS IN SOUTHERN STREAM AS IT MERGES WITH SUBTROPICAL JET ALONG SE
CONUS COAST. NORTHERN BRANCH JET IS WEST-EAST ACROSS NORTHERN PLAINS
AND GREAT LAKES. EXPECTATION IS THAT INTO EARLY THIS WEEK...JET
CRASHING INTO WEST COAST WILL DIG INTO SOUTHERN CA/BAJA CA WHILE
CARVING A TROUGH OUT OVER SW CONUS. AS THIS IS OCCURRING...TWO MAIN
PIECES OF SHORTWAVE ENERGY...CURRENTLY OFFSHORE OF BRITISH COLUMBIA
WITH THE OTHER WELL TO WEST OF CA WILL PHASE TOGETHER WITHIN THIS
MEAN TROUGH. PHASING WOULD APPEAR TO BE DONE BY MON MORNING...SO
THEN IT JUST BECOMES A TRACK FORECAST OF THE SHORTWAVE TROUGH AND
ASSOCIATED SFC LOW. LATEST GUIDANCE STILL IN GOOD AGREEMENT ON SFC
LOW MOVING TO NORTHERN LOWER/EASTERN UPR MICHIGAN BY WED MORNING.
UPSHOT IS THAT STRONG STORM WITH SNOW/WIND REMAINS ON TRACK FOR UPR
MICHIGAN TUE NIGHT INTO WED.
BACK OVER UPR LAKES IT LOOKS PRETTY QUIET IN THE LEAD UP TIME TO THE
POTENTIAL STORM. NORTHERN STREAM FLOW REMAINS ACROSS GREAT LAKES
EARLY IN THE WEEK. STRONG SFC LOW MOVING BY OVER ONTARIO AND QUEBEC
THIS AFTN WILL LEAD A SFC TROUGH/COLD FRONT TO ITS WEST. BY LATE SUN
THIS FRONT SHOULD STILL BE NORTH OF UPR MICHIGAN/LK SUPERIOR THOUGH
LEAD TROUGH MAY BE THROUGH UPR MICHIGAN BY THAT TIME. LEAD WAVE IN
THE NORTHERN STREAM WORKS THROUGH ON SUN NIGHT WITH WEAK LARGE SCALE
LIFT. MAIN AFFECT OF THE WAVE WILL BE TO BRING H85 COLD FRONT OVER
UPR MICHIGAN ALONG WITH INCREASING H9-H8 MOISTURE AND PUSH SFC COLD
FRONT OVER LK SUPERIOR. ONSHORE FLOW AND TEMPS AT TOP OF INVERSION
MARGINALLY COLD FOR LAKE EFFECT /MAYBE LOWER THAN -10C/ SHOULD LEAD
TO LIGHT LAKE EFFECT PRECIPITATION SUN NIGHT INTO MON FOR NW-N FLOW
AREAS. WITH GOOD PART OF THIS TIME FEATURING TEMPS -8C OR WARMER
ALSO PUT MENTION OF FZDZ IN THE GRIDS. PROBABLY LOOKING AT FLURRIES
AND FZDZ SUN NIGHT THEN BETTER SHOT AT SNOW SHOWERS MON AS IT TURNS
SLIGHTLY COOLER AT H85. BEST CHANCE OF MUCH PRECIP THROUGHOUT WILL
BE OVER NW INTO NCNTRL CWA WITH UPSLOPE NW FLOW. OVERALL NOT LOOKING
AT MUCH SNOW WITH LIMITED CONVERGENCE AND MINIMAL COLD AIR. HINT
THAT ANOTHER WEAK WAVE WORKS THROUGH LATE MON INTO MON EVENING WITH
MORE OF WIDESPREAD LGT SNOW/FLURRIES. WARM AIR ADVECTION COULD LEAD
TO MORE FZDZ LATER AT NIGHT AS DEEPER MOISTURE/FORCING ARE REMOVED.
ATTN TUE MORNING WILL BE ON THE WINTER STORM ONGOING OVER THE HIGH
PLAINS. STEADY MODERATE TO HEAVY SNOW SHOULD BE SPREADING ACROSS
MUCH OF CO/KS/SW NEB AND HEADING TOWARD EASTERN NEB/WESTERN IA. SFC
LOW SHOULD BE VCNTY OF KS/OK BORDER. AS SHRA/TSRA START DEVELOPING
IN THE WARM SECTOR DOWN THE MISSISSIPPI RIVER VALLEY...SNOW WILL BE
EXPANDING AND INCREASING ON TUE AS IT CROSSES FM MID MO RIVER VALLEY
TOWARD WESTERN GREAT LAKES LATE IN THE DAY AS DEEP GULF MOISTURE IS
INGESTED INTO THE SYSTEM. STRONG DEEP LAYER Q-VECTOR CONVERGENCE AND
STRONG UPPER LEVEL DIFFLUENCE AND DIVERGENCE ALOFT IN EXIT REGION OF
150+ KTS JET STREAK OVER SOUTHERN PLAINS SHOULD AID IN WIDESPREAD
HEAVY SNOW DEVELOPING AS IT MOVES INTO THE WESTERN GREAT LAKES.
EXPECT MODERATE SNOW TO REACH SCNTRL UPR MICHIGAN DURING THE AFTN.
FARTHER NORTH...EAST WINDS AND TEMPS IN LOW-LEVEL MOIST LAYER -8C TO-
10C SHOULD ALLOW SNOW TO START TO EXPAND NW/NCNTRL BY LATE DAY
THOUGH INTENSITY SHOULD BE HELD DOWN AS DEEP MOISTURE IS LIMITED
ABOVE 850MB UNTIL RIGHT AT 00Z. WORTH SMALL CHANCE POPS WHILE
SPREAD LIKELY POPS OVER THE SCNTRL IN THE AFTN.
BULK OF STORM OCCURS TUE NIGHT THROUGH MIDDAY WED. AS THE SFC LOW
REACHES NORTHERN LK MICHIGAN/NORTHERN LOWER MICHIGAN BY 12Z WED...
EXPECT WIDESPREAD SNOW OVER ALL OF UPR MICHIGAN. BASED ON TRACK OF
H85-H7 LOWS...HEAVIEST STRIPE OF SNOW WILL BE OVER CNTRL CWA. MOST
AREAS WILL SEE HEAVY SNOW FOR A TIME THOUGH AND WARNING AMOUNTS OF
AT LEAST 6 INCHES/12 HOURS WOULD BE MET. LAKE ENHANCEMENT/UPSLOPE
NORTHEAST WINDS WITH H85 TEMPS DOWN BLO -10C WILL ADD TO SNOW
INTENSITY AND TOTALS FOR NCNTRL CWA. THOUGH BULK OF SYSTEM SNOW
REMAINS TO EAST OF WESTERN CWA...COLDER TEMPS/HIGHER SLR/S AND
FAVORABLE NRLY FLOW WILL RESULT IN SEVERAL INCHES OF SNOW AND
POSSIBLE WARNING AMOUNTS THERE AS WELL. LAST...BUT CERTAINLY NOT
LEAST IS THE NORTH WINDS OVER 20 MPH WITH HIGHER GUSTS THAT WILL
LEAD TO CONSIDERABLE BLOWING SNOW AND REDUCED VSBY. AT LEAST
LOCALIZED BLIZZARD CONDITIONS COULD OCCUR. LAKE ENHANCED SNOW OR AT
LEAST LAKE EFFECT CONTINUES INTO WED AFTN/WED EVENING. SOME SLIGHT
DIFFERENCES IN TRACK OF LOW...WITH ECMWF MORE OVER ALPENA AT 12Z WED
AND GEM OVER CNTRL LK MICHIGAN. THERE WILL STILL BE SOME ADJUSTMENTS
BUT OVERALL FLAVOR OF RECENT FORECASTS WITH THIS STORM ARE STILL ON
TRACK.
BEHIND THIS SYSTEM...MEAN TROUGHING AND COLD AIR WITH H85 TEMPS DOWN
IN THE -15C TO -20C RANGE WILL KEEP LAKE EFFECT GOING FOR NW FLOW
AREAS. RETAINED PREVIOUS SHIFTS HIGHER POPS OVER CONSENSUS. MAY TURN
EVEN COLDER FOR NEXT WEEKEND...SO THE LAKE EFFECT WILL CONTINUE.
AFTER THE MILD BREAK TODAY AND SUNDAY...LOOKS TO REMAIN WINTRY ON
INTO MID FEB.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1253 PM EST SAT JAN 30 2016
W TO SW FLOW OF RELATIVELY DRY PACIFIC AIR WILL MAINTAIN VFR
CONDITIONS THROUGH THIS EVENING. DIURNAL COOLING AND A WEAK TROUGH
MOVING INTO UPPER MICHIGAN IS EXPECTED TO BRING IN LOWER CLOUDS
OVERNIGHT WITH MVFR CIGS AT CMX AND SAW AND IFR AT IWD. SOME VSBY
REDUCTION WITH FOG IS ALSO POSSILBE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 550 AM EST SAT JAN 30 2016
STRONG LOW TRACKING OVER NORTHERN ONTARIO THIS MORNING WILL RESULT
IN SOUTHWEST WINDS 20-30 KTS TODAY. WINDS DIMINISH TONIGHT INTO SUN
AS RIDGING MOVES OVERHEAD. A LOW PRESSURE SYSTEMS TRACKING ACROSS
THE CENTRAL GREAT LAKES WILL LIKELY BRING NORTH TO NORTHEAST GALES
TUE NIGHT INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
349 PM EST SAT JAN 30 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 346 PM EST SAT JAN 30 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A MAINLY ZONAL MID/UPPER LEVEL
PATTERN ACROSS THE CONUS. A WEAK UPSTREAM SHORTAVE TROUGH WAS MOVING
INTO THE NRN PLAINS. AT THE SFC...A 984 MB LOW WAS MOVING THROUGH
NRN ONTARIO TOWAD JAMES BAY RESULTING IN SW TO W FLOW OR MILD
PACIFIC AIR INTO THE REGION. TEMPS HAVE CLIMBED TO NEAR OR ABOVE
RECORD VALUES WITH 44F AT THE NWS OFFICE BREAKING THE OLD RECORD OF
41. VIS LOOP SHOWED MOSTLY CLEAR SKIES OVER MOST OF UPPER MI WITH
MID/HIGH CLOUDS GRADUALLY SPREADING INTO THE SOUTH.
TONIGHT INTO SUN...MILD CONDITIONS WILL PREVAIL AS A WEAK TROUGH
INTO CNTRL MN MOVES INTO THE REGION. A BAND OF 800-600 MB FGEN
ASSOCIATED WITH A JET STREAK LIFTING NE FROM THE NRN LAKES WILL HELP
SUPPORT AN AREA OF PCPN FROM CNTRL INTO NE WI AND INTO FAR SRN AND
POSSIBLY SE UPPER MI. MODELS CONSENSUS SUGGESTS THAT QPF AMOUNTS TO
AROUND 0.10 INCH FROM 06Z-18Z MAY AFFECT LOCATIONS NEAR MNM.
HOWEVER...GIVEN THE MODELS SPREAD...CONFIDENCE IS MARGINAL AND MAINLY
CHNANCE POPS WERE MENTIONED EXCEPT AT MNM (60 POP) AROUND 12Z. LOW
LEVEL TEMP PROFILES SUPPORT MAINLY RAIN AS THE PCPN TYPE.
HOWEVER...WITH TEMPS FALLING TO NEAR 32F A BIT FARTHER INLAND...SOME
FZRA/SN MAY ALSO MIX WITH THE PCPN. SO...EVEN THOUGH LITTLE OR NO
ICE/SNOW ACCUMULATIONS ARE EXPECTED ANY SMALL AMOUNTS ON UNTREATED
SURFACES COULD STILL CREATE HAZARDOUS CONDITIONS. AS THE DEEPER
MOISTURE MOVES OUT IN THE MORNING...AND LOW LEVEL MOISTURE LINGERS
ALONG THE TROUGH/FRONT...SOME DZ/FZDZ WILL BE POSSIBLE OVER THE SE
HALF. TEMPS WILL REMAIN WELL ABOVE NORMAL WITH HIGHS FROM THE LOWER
30S OVER THE NW HALF TO THE MID AND UPPER 30S OVER THE S AND E.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 550 AM EST SAT JAN 30 2016
AN ACTIVE 7 DAY PERIOD IS SHAPING UP. THE CURRENT CHANGE TO A MORE
ZONALLY ORIENTED FLOW ACROSS THE CONUS WILL TRANSITION NEXT WEEK TO
A MORE AMPLIFIED RIDGE IN THE VCNTY OF THE W COAST OF N AMERICA AND
A CORRESPONDING DOWNSTREAM TROF OVER CNTRL AND ERN N AMERICA. AS
THIS OCCURS...VIGOROUS SRN STREAM ENERGY WILL MOVE ACROSS THE SW
STATES EARLY NEXT WEEK BEFORE LIFTING NE INTO THE GREAT LAKES
MIDWEEK ON THE FRONT SIDE OF THE DEVELOPING CNTRL/ERN NAMERICA TROF.
OVER THE LAST 24HRS...THE OVERALL MODEL TREND FROM THE
GFS/CANADIAN/ECMWF/UKMET IS TO OPEN UP THE MID LEVEL ENERGY AS IT
MOVES INTO THE GREAT LAKES. AS A RESULT...THE ASSOCIATED SFC LOW
TRACK TRENDED FARTHER E IN RESPONSE TO THE WEAKENING ENERGY ALOFT.
00Z GFS/ECMWF HAVE REVERSED THAT TREND. MORE ON THIS LATER. PRIOR TO
THE MID WEEK SYSTEM...THERE WAS SOME GROWING CONCERN FOR A POTENTIAL
HEADLINE SNOW EVENT LATER SUN INTO EARLY MON PER NAM/GFS DUE TO
POSSIBLE INTERACTION OF A COUPLE OF SHORTWAVES LEADING TO A
DEEPENING SYSTEM MOVING THRU THE WRN GREAT LAKES. THE NAM WAS
ESPECIALLY STRONG...SHOWING WIDESPREAD SIGNIFICANT SNOW ACROSS MOST
OF THE FCST AREA FOR SEVERAL RUNS. WITH THE 00Z RUNS...THE GFS/NAM
HAVE BOTH TRENDED TOWARD THE FLATTER/WEAKER NON NCEP MODELS. THE
CHANGE IN THE NAM IS VERY DRAMATIC...FOR INSTANCE GOING FROM 1 INCH
OF QPF IN NCNTRL UPPER MI TO JUST A FEW HUNDREDTHS WITH THE 00Z
RUN...AN EPIC FAIL FOR THE NAM. AS FOR TEMPS...TEMPS WILL BE WELL
ABOVE NORMAL THRU SUN...ESPECIALLY TODAY...DUE TO MILD PACIFIC AIR
BEING DRIVEN EASTWARD IN THE BRIEF/TEMPORARY SHIFT TO MORE ZONALLY
ORIENTED FLOW. TEMPS WILL THEN SLOWLY TREND DOWN NEXT WEEK TO AT
LEAST A LITTLE BLO NORMAL IN THE WAKE OF THE MID WEEK STORM. LOOKING
FARTHER AHEAD...CANADIAN ENSEMBLES/NAEFS HAVE CONTINUED THE RECENT
TREND TOWARD A COLDER WEATHER PATTERN THRU THE 2ND WEEK OF FEB. WITH
A STRENGTHENING WRN RIDGE/ERN TROF PATTERN...WOULDN`T BE SURPRISED
TO SEE AN ARCTIC AIR MASS DIVE INTO THE UPPER LAKES THAT WILL BE AS
COLD OR COLDER THAN WE`VE SEEN SO FAR DURING THIS OVERALL MILD
WINTER SEASON. OF COURSE...WITH A BLO NORMAL TEMP REGIME SETTING
UP...LAKE EFFECT SNOW WILL BE VERY ACTIVE LATE IN THE UPCOMING WEEK
THRU THE 2ND WEEK OF FEB.
BEGINNING SUN/SUN NIGHT...AS MENTIONED ABOVE...THERE HAS BEEN A
DRAMATIC SHIFT OF THE GFS/NAM TOWARD THE FLATTER/WEAKER NON NCEP
MODEL GUIDANCE WHICH ONLY TRENDED SLIGHTLY STRONGER OVER THE LAST
24HRS WITH RESPECT TO THE SHORTWAVE ENERGY MOVING THRU THE WRN GREAT
LAKES. AS A RESULT...MODEL AGREEMENT IS NOW QUITE GOOD. IT APPEARS
THAT PCPN DEVELOPMENT ASSOCIATED WITH A SHORTWAVE MOVING THRU THE
WRN GREAT LAKES WILL LARGELY PASS S AND E OF THE FCST AREA AS
FORCING FROM RIGHT ENTRANCE OF UPPER JET AND LOW-MID LEVEL FGEN PASS
S AND E OF HERE. WILL MAINTAIN SOME CHC POPS OVER THE FAR SCNTRL/ERN
FCST AREA FOR SUN/SUN EVENING...BUT THAT MAY BE GENEROUS. PER FCST
SOUNDINGS...PTYPE IN THAT AREA MAY BE A MIX OF -SN/-FZRA/-RA SUN.
ELSEWHERE...THERE MAY NOT BE ANY PCPN TO SPEAK OF SUN/SUN NIGHT.
HOWEVER...INCLUDED SCHC POPS NEAR LAKE SUPERIOR AS UPSLOPE FLOW MAY
HELP GENERATE SOME FLURRIES/-SHSN AS 850MB TEMPS SLOWLY FALL TO THE
MARGINAL THRESHOLD FOR LES. NOT OUT OF THE QUESTION THAT THERE COULD
BE SOME ISSUES WITH -FZDZ IF THE NAM IS CORRECT WITH SHALLOW
SATURATED SFC BASED LAYER THAT HAS TEMPS AOA -10C.
WITH 850MB TEMPS FALLING SLIGHTLY MORE MON/MON NIGHT...MIGHT SEE AN
INCREASE IN LIGHT LES/FLURRIES OFF LAKE SUPERIOR AS WINDS VEER
SLOWLY FROM NW TO A MORE NORTHERLY DIRECTION.
ATTENTION THEN TURNS TO THE LONG ADVERTISED POTENTIAL WINTER STORM
FOR MIDWEEK. AS MENTIONED ABOVE...AFTER AN OVERALL MEDIUM RANGE
MODEL TREND FOR A SFC LOW TRACK SHIFTED SLIGHTLY SE...TODAYS 00Z
GFS/ECMWF HAVE SHIFTED NOTABLY LEFT/W WITH THE TRACK...BACK TO WHAT
WAS CONSIDERED THE CONSENSUS TRACK ON THU...RUNNING FROM THE SRN
PLAINS NE ACROSS NRN LWR MI. ACTUALLY...THE 00Z ECMWF/GFS TRACK IS A
EVEN A BIT FARTHER LEFT/W OF THE THU CONSENSUS TRACK AS THEY TAKE
THE LOW ACROSS NRN LAKE MI INTO FAR ERN UPPER MI. THE CANADIAN IS
STILL FARTHER SE AND HAS MOST OF THE SYNOPTIC PCPN PASSING SE OF THE
FCST AREA. THERE ARE A NUMBER OF CANADIAN ENSEMBLES SUPPORTING A
TRACK ACROSS NRN LWR MI...EVEN A COUPLE THAT TAKE THE LOW EVEN
FARTHER W THRU CNTRL UPPER MI IN ADDITION TO SEVERAL FARTHER SE
TRACKS. THE GFS ENSEMBLES HAVE A SIMILAR SPREAD THOUGH OVERALL
SLIGHTLY NW OF THE CANADIAN ENSEMBLES. AT THIS POINT...WILL CONTINUE
TO FAVOR A TRACK NE ACROSS NRN LWR MI BASED ON SEVERAL DAYS OF MODEL
RUNS...WHICH SUGGESTS A GOOD POTENTIAL FOR SNOW ACCUMULATIONS TO
REACH/EXCEED WARNING CRITERIA OVER MUCH OF THE FCST AREA. NE TO N
FLOW UPSLOPE/LAKE ENHANCEMENT DURING THE SYNOPTIC FORCING STILL
POINTS TOWARD THE HIGH TERRAIN OF NCNTRL UPPER MI BEING FAVORED FOR
THE GREATEST SNOW TOTALS. RAPID MOVEMENT OF THE SYSTEM AND THE LACK
OF A WELL ORGANIZED MID LEVEL CENTER WILL KEEP SNOW AMOUNTS FROM
GETTING ESPECIALLY HIGH. CONSIDERING THE LACK OF SYNOPTIC STORM
SYSTEMS THAT HAVE AFFECTED UPPER MI DURING THIS COLD SEASON...THIS
SHOULD BE A GOOD SNOW EVENT IF THE SYSTEM INTENSITY AND TRACK WORKS
OUT AS EXPECTED NOW.
FOLLOWING THE MID WEEK STORM...LES WILL BE THE RULE OFF LAKE
SUPERIOR THRU LATE WEEK IN GENERAL W TO NW LOW-LEVEL FLOW UNDER
850MB TEMPS BTWN -14 AND -20C. LOOKS LIKE THERE MAY BE ONE OR MORE
SHORTWAVES PASSING TO PROVIDE BRIEF PERIODS OF ENHANCEMENT TO THE
LES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1253 PM EST SAT JAN 30 2016
W TO SW FLOW OF RELATIVELY DRY PACIFIC AIR WILL MAINTAIN VFR
CONDITIONS THROUGH THIS EVENING. DIURNAL COOLING AND A WEAK TROUGH
MOVING INTO UPPER MICHIGAN IS EXPECTED TO BRING IN LOWER CLOUDS
OVERNIGHT WITH MVFR CIGS AT CMX AND SAW AND IFR AT IWD. SOME VSBY
REDUCTION WITH FOG IS ALSO POSSILBE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 550 AM EST SAT JAN 30 2016
STRONG LOW TRACKING OVER NORTHERN ONTARIO THIS MORNING WILL RESULT
IN SOUTHWEST WINDS 20-30 KTS TODAY. WINDS DIMINISH TONIGHT INTO SUN
AS RIDGING MOVES OVERHEAD. A LOW PRESSURE SYSTEMS TRACKING ACROSS
THE CENTRAL GREAT LAKES WILL LIKELY BRING NORTH TO NORTHEAST GALES
TUE NIGHT INTO WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...ROLFSON
AVIATION...JLB
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1246 PM CST SAT JAN 30 2016
.UPDATE...
ISSUED AT 1239 PM CST SAT JAN 30 2016
SHORTWAVE TRACKING ALONG THE ND/SD BORDER HAD PRODUCED UP TO ABOUT
A QUARTER INCH OF SNOW OVER A SMALL PORTION OF SOUTHWEST NORTH
DAKOTA. EXPECT MAINLY TRACE AMOUNTS ASSOCIATED WITH THE WAVE AS IT
TRACKS THROUGH THE FAR SOUTH CENTRAL IN CONFLUENT FLOW ALOFT. WILL
STILL KEEP SLIGHT CHANCE POPS AT LEAST THROUGH MID AFTERNOON TO
COVER THIS. MADE SOME ADJUSTMENTS TO TEMPERATURES WITH COOLER
CONDITIONS OVER THE SOUTHWEST AND SOUTH CENTRAL WHERE THE SNOW
FELL. WARMER ACROSS THE NORTH WITH A LOT MORE SUNSHINE.
UPDATE ISSUED AT 856 AM CST SAT JAN 30 2016
FOR THE MORNING UPDATE WILL ADJUST POPS SOME OVER SOUTHWEST NORTH
DAKOTA. LATEST MESOSCALE MODELS LOOK TO BE VERIFYING A LITTLE TOO
FAR SOUTH WHEN COMPARED TO THE LATEST BOWMAN RADAR LOOP. HAVE
ADJUSTED POPS A LITTLE FARTHER NORTH AND UPPED POPS TO HIGHER
CHANCE. STILL PROBABLY PRETTY HARD FOR ANY ONE AREA TO GET
MEASURABLE PRECIP BUT THERE IS ENOUGH GROUND TRUTH WITH SNOW AT
BAKER...A MIX THEN SNOW AT DICKINSON...PLUS RETURNS ON RADAR...TO
JUSTIFY BUMPING UP POPS. MESOSCALE MODELS KEEP CHANCE OF PRECIP
AND EVEN SOME WEAK CAPE OVER THE SOUTHWEST THROUGH THE AFTERNOON
SO WILL LEAVE SMALL POPS AS PREVIOUSLY FORECAST THROUGH THE
AFTERNOON. OTHERWISE NO SIGNIFICANT UPDATES TO THE GOING FORECAST.
UPDATE ISSUED AT 635 AM CST SAT JAN 30 2016
NO SIGNIFICANT CHANGES WERE MADE WITH THIS UPDATE...THOUGH WE DID
PUSH LOW-END POPS A BIT FURTHER EAST INTO FAR SOUTH CENTRAL ND
TODAY BASED ON RECENT HRRR SIMULATIONS AND THE 06 UTC NAM. A MIX
OF RAIN AND SNOW REMAINS PRUDENT IN THE FORECAST IN PLACES WHERE
WE DO HAVE POPS GIVEN THERMAL PROFILES NEAR THE FREEZING MARK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SAT JAN 30 2016
THE MAIN FOCUS FOR THE SHORT TERM FORECAST IS PRECIPITATION
CHANCES ACROSS THE SOUTHWEST.
EARLY THIS MORNING A WEAK UPPER LEVEL SHORT WAVE TROUGH WAS
PUSHING ACROSS EASTERN MONTANA. THIS WILL PROVIDE THE ASCENT
NEEDED TO SPARK SOME LIGHT PRECIPITATION TODAY ACROSS THE
SOUTHWEST. BOWMAN RADAR CONTINUES TO INDICATE VERY LIGHT
PRECIPITATION IS POSSIBLE ACROSS THE SOUTHWEST. HOWEVER...NO
SURFACE OBSERVATIONS OR WEBCAMS HAVE RECORDED ANYTHING OF NOTE SO
FAR THIS MORNING. A MIX OF RAIN...FREEZING RAIN...SLEET AND SNOW
IS POSSIBLE WITH TEMPERATURES ALOFT WITHIN ONE OR TWO DEGREES OF
FREEZING AND SURFACE TEMPERATURES ALSO HOVERING AROUND FREEZING.
HOWEVER...SHORT TERM MODELS AND RADAR TRENDS INDICATE ONLY VERY
LIGHT AND SCATTERED PRECIPITATION MAY FALL...THEREFORE...NO MAJOR
IMPACTS ARE ANTICIPATED.
WITH WESTERLY WINDS AND NEARLY NEUTRAL TEMPERATURE ADVECTION
THROUGH MOST OF THE DAY...TEMPERATURES WILL LIKELY CLIMB BACK
INTO THE 40S ACROSS MOST OF THE SOUTH WEST AND SOUTH CENTRAL.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CST SAT JAN 30 2016
SEASONABLY COLD WEATHER WILL PREVAIL DURING THE LONG TERM...WITH
ONLY A FEW LOW-GRADE OPPORTUNITIES OF LIGHT SNOW.
THE 00 UTC GLOBAL MODEL SUITE REMAINED IN GOOD AGREEMENT WITH ITS
DEPICTION OF NORTHWEST FLOW ALOFT DEVELOPING ACROSS THE REGION AS
A MEAN 500-MB TROUGH BECOMES ESTABLISHED OVER THE CENTRAL UNITED
STATES THIS WEEK. THIS WILL PROVIDE A RELATIVELY STEADY SUPPLY OF
COLD AIR ADVECTION TO THE NORTHERN PLAINS...ESPECIALLY AS LARGER-
SCALE FLOW AMPLIFIES IN RESPONSE TO WARM AIR ADVECTION AND HEIGHT
RISES ALOFT DOWNSTREAM OF THE POWERFUL STORM EXPECTED TO MOVE FROM
THE CENTRAL PLAINS TO THE GREAT LAKES BY MIDWEEK. A COOLING TREND
WILL RESULT WITH HIGHS FALLING FROM 25 TO 35 F SUNDAY TO 10 TO 25
F TUESDAY THROUGH FRIDAY /COLDEST IN NORTH CENTRAL ND/.
WELL-ESTABLISHED CYCLONIC FLOW IN THE EXPECTED WEATHER REGIME MAY
YIELD A LITTLE LIGHT SNOW ON SOME DAYS...ESPECIALLY WHEN EMBEDDED
VORTICITY MAXIMA TRAVERSE THE REGION. THE PREDICTABILITY OF THOSE
FEATURES IS GENERALLY LOW IN THIS PATTERN...BUT THE 00 UTC ECMWF
AND GFS BOTH SUGGESTED WEAK WAVES MAY CROSS THE AREA BOTH MONDAY
AND WEDNESDAY. OUR MODEL-BLEND-DRIVEN FORECAST THUS HAS LOW POPS
IN THOSE TIME PERIODS...MAINLY OVER WESTERN ND WHERE THE THERMAL
GRADIENT IN THE MIDDLE ATMOSPHERE WILL BE GREATEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CST SAT JAN 30 2016
EXPECT MAINLY VFR CONDITIONS THROUGH THE FORECAST PERIOD. WEST TO
NORTHWEST FLOW WILL CONTINUE. A PERIOD OF MVFR CEILINGS THROUGH
20Z AT KDIK AS LIGHT SNOW EXITS THIS AREA. OTHERWISE EXPECT LOW
VFR CONDITIONS HERE AND KBIS WITH ONLY THIN HIGH CLOUDS AT KISN
KMOT. LOWER CEILINGS WILL MOVE INTO THE SOUTHWEST AGAIN ON SUNDAY
WITH POSSIBLE MVFR CEILINGS AT KDIK AFT 15 UTC SUNDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...AJ
LONG TERM...CJS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS PORTLAND OR
902 AM PST SAT JAN 30 2016
.SYNOPSIS...COOL AND UNSETTLED WITH SHOWERY WEATHER THROUGH WED...
WITH SNOW LEVELS BELOW PASSES OF THE CASCADES. BUT WILL SEE RETURN OF
RAIN AND HIGHER SNOW LEVELS WITH A MORE ORGANIZED FRONT TOWARDS THU
AND FRI.
&&
.SHORT TERM...TODAY THROUGH MONDAY...NOT MUCH CHANGE THIS AM.
STEADY COLD UNSTABLE AIR ALOFT RIDING WESTERLY WINDS INTO THE REGION.
THIS WILL KEEP SHOWERS TODAY. WITH SNOW LEVELS HOLDING NEAR 2000
FEET...WILL SEE SMALL HAIL IN SOME OF THE HEAVIER SHOWERS. EMBEDDED
SHORTWAVES WILL ENHANCE SHOWER ACTIVITY THIS AFTERNOON AND EVENING
ESPECIALLY N OF A LINCOLN CITY TO SANTIAM PASS LINE. THE AIR MASS IS
UNSTABLE ENOUGH FOR SOME ISOLATED THUNDERSTORMS OVER THE WATERS THIS
WEEKEND. THUNDERSTORMS MAY ALSO EXTEND INLAND WITH DAYTIME INSOLATION
TODAY AND AGAIN SUNDAY.
CASCADES WILL SEE DECENT SNOW ACCUMULATIONS IN THE CASCADES TODAY
AS SNOW LEVELS LOWER TO AROUND 1500 TO 2000 FEET. THE ONSHORE FLOW
EASES SOME THIS AFTERNOON AND TONIGHT SO SNOWFALL RATES WILL DECREASE
AS WELL. SNOW SHOWERS WILL CONTINUE INTO SUNDAY BUT ACCUMULATIONS
ARE EXPECTED TO REMAIN BELOW ADVISORY CRITERIA. WITH THE LOW SNOW
LEVELS THE COAST RANGE AND CASCADE FOOTHILLS WILL ALSO SEE SOME SNOW.
HIGHER PASSES CROSSING THE COAST RANGE MAY SEE LIGHT ACCUMULATIONS
TONIGHT AND SUNDAY.
THERE IS STILL A CHANCE OF SHOWERS WITH SNOW IN THE MOUNTAINS MONDAY
UNDER NORTHWESTERLY FLOW ALOFT AND AT LOW LEVELS. SNOW LEVELS WILL
REMAIN AROUND 1500 FT.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MONDAY NIGHT THROUGH FRIDAY...A WEAK SHORTWAVE TROUGH LOOKS TO
QUICKLY MOVE ACROSS THE PAC NW TUESDAY MAINTAINING OUR SHOWERY
PATTERN. SNOW LEVELS WILL HOVER AROUND 2000 FT SO SOME LIGHT
ACCUMULATIONS IN THE CASCADES...FOOTHILLS...AND COAST RANGE APPEAR
LIKELY. UPPER LEVEL RIDGING LOOKS TO MOVE INTO THE REGION LATE
TUESDAY AND COULD BRING A BRIEF PERIOD OF DRY WEATHER THROUGH
WEDNESDAY SO HAVE LOWERED POPS ACROSS THE FORECAST AREA TO AROUND 20
PERCENT OR LESS. MODELS CONTINUE TO SHOW A FRONT APPROACHING THE
COAST NEXT WEEK BUT HAVE SLOWED IT DOWN A BIT. THE FRONT IS NOW
EXPECTED TO MOVE ACROSS THE REGION THURSDAY...WITH SNOW LEVELS
RISING TO AROUND 4000 FT LATE THURSDAY. UPPER LEVEL RIDGING LOOKS TO
BUILD BEHIND THE FRONT LATE THURSDAY AND COULD GIVE US A FEW DAYS OF
DRY WEATHER LATE NEXT WEEK. EXPECT SEASONAL TEMPS THROUGH THE
FORECAST PERIOD. /64
&&
.AVIATION...SHOWERY AND UNSTABLE ONSHORE FLOW CONTINUES TODAY AND
TONIGHT. MVFR CIGS FORMED EARLIER THIS MORNING OVER THE INTERIOR
LOWLANDS FROM AROUND KSLE AND AREAS NORTHWARD. EXPECT THAT THIS
MVFR DECK WILL BREAK UP BY AROUND 18Z AS A BAND OF SHOWERS MOVES
THROUGH. THEN EXPECT PREDOMINANTLY VFR CONDITIONS THROUGH
TONIGHT...WITH OCCASIONAL MVFR POSSIBLE IN HEAVIER SHOWERS.
THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AGAIN TODAY WITH SMALL
HAIL POSSIBLE AS WELL. CONFIDENCE IN TIMING OR LOCATION OF
THUNDERSTORMS IS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS.
KPDX AND APPROACHES...AN MVFR DECK SHOULD BREAK UP BY AROUND 18Z.
THEN EXPECT MAINLY VFR CONDITIONS WITH OCCASIONAL SHOWERS THROUGH
TONIGHT. BRIEF PERIODS OF MVFR POSSIBLE IN HEAVIER SHOWERS. THERE
IS ALSO A SLIGHT CHANCE FOR A THUNDERSTORM THROUGH THE DAY. PYLE
&&
.MARINE...WINDS GENERALLY 10 TO 15 KT OUT OF THE WEST THROUGH THIS
EVENING. A WEAK SURFACE LOW CURRENTLY ALONG THE B.C. COAST WILL
WEAKEN FURTHER STILL AND WORK SLOWLY SOUTH THROUGH WESTERN
WASHINGTON AND OREGON TONIGHT AND SUN. THIS MAY BRING A PERIOD OF
20 TO 25 KT NW WINDS FROM EARLY SUN MORNING THROUGH THE AFTERNOON.
ISOLATED THUNDERSTORMS WILL REMAIN A POSSIBILITY THROUGH
SUNDAY...WHICH ANY STORMS BRINGING THE POTENTIAL FOR BRIEF WIND
GUSTS TO 30 KT. A DECAYING FRONT WILL MOVE THROUGH THE WATERS MON
NIGHT INTO TUE MORNING. THIS SYSTEM IS LOOKING WEAKER AND WEAKER
IN THE MODELS AND MAY DO LITTLE OTHER THAN SHIFT THE WINDS BACK TO
THE SOUTH. A STRONGER FRONT IS EXPECTED WED NIGHT INTO THU. THIS
SYSTEM WILL LIKELY BRING AT LEAST SMALL CRAFT ADVISORY
WINDS...WITH THE POTENTIAL FOR GALES.
SEAS REMAIN AROUND 12 TO 14 RANGE TODAY WITH THE PRIMARY SWELL OUT
OF THE WEST. THEY WILL CONTINUE TO GRADUALLY SUBSIDE THROUGH THE
WEEKEND...FINALLY DROPPING BELOW 10 FT LATE SUN OR EARLY MON. SEAS
THEN REMAIN BELOW 10 FT FOR THE FIRST HALF OF NEXT WEEK. ANOTHER
LONG PERIOD WESTERLY SWELL IS MODELED TO ARRIVE DURING THE SECOND
HALF OF NEXT WEEK...LIKELY PUSHING SEAS BACK INTO MID TEENS. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR CASCADES IN
LANE COUNTY-NORTHERN OREGON CASCADES.
WA...WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST SUNDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL MIDNIGHT
PST TONIGHT.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
354 AM PST SAT JAN 30 2016
.SYNOPSIS...
An upper level trough will settle over the region today and
linger through Monday. This will result in seasonal temperatures
with a chance of snow showers. Expect a short dry period through
mid-week then a more organized system approach again toward next
Thursday.
&&
.DISCUSSION...
Today through Sunday night...The ridge of high pressure has been
replaced by a long wave trough over the region. This will put the
region into more of a westerly flow and effectively cut the region
off from the deep Pacific moisture tap that has been over the
Pacific Northwest for most of the week. But that doesn`t mean
conditions will be totally dry. The cold core will track across
the forecast area today. This will destabilize the atmosphere. In
addition model guidance has been pretty consistent showing a
series of weak short wave disturbances moving through the area
today through Sunday. Enough moisture will linger for scattered
rain and snow showers both days. The best chance for showers will
be on the lee side of the Cascades and of course in the
orographically favored Panhandle mountains and the Blue mountains.
However, in this type of a pattern just about anywhere could pop
an intense, short lived shower. Precipitation would be mainly as
snow with rain/snow mix for the lower elevations and possibly some
graupel. The NAM and HRRR models have been picking up on a
particularly robust wave this morning across the southeast zones,
from the Camas Prairie north to around Pullman and Avery. As such
pops were bumped up in this area. A fast couple of inches of
snowfall could be possible with these showers. Pretty tough to
pinpoint just exactly where these will form so no highlights are
expected and we will handle this with Nowcasts and social media as
best we can. Temperatures should be within a degree or two of
seasonal normals. Southwest winds across the southeast zones will
remain slightly elevated today with sustained winds 10-15 mph and
gusts around 25 mph through most of the day.
The upper level trough will shift east Saturday night through
Monday as a high amplitude ridge tracks from about 150W to near
the coast. This will shift the flow into an even drier northwest-
north flow. Isolated to scattered showers will linger near the
Cascade crest, the northeast mountains with light snow
accumulations at times. Northwest-northerly flow supports a better
chance for showers for the Panhandle mountains and this is an
excellent set up for the Blues and Camas Prairie. While showers
will remain in the forecast, we expect less moisture to work with
and the train of weak disturbances will get cut-off. I wouldn`t be
surprised if a few spots pick up an inch or two of snow. But this
will be isolated and widely scattered. Tobin
Monday through Tuesday night...Shortwave energy will continue to
keep a chance of snow showers across the forecast area through
Tuesday but mainly confined to the Cascade crest and the eastern
third of the forecast area. The northerly overland trajectory will
keep any snowfall accumulations rather light. By Tuesday night the
offshore ridge axis will start to migrate east. This will relegate
any lingering precipitation to the Idaho panhandle. Daytime
temperatures will be in the 30s with low 40s for the southernmost
valleys. Overnight lows will be on a cooling trend as northerly flow
keeps bringing colder air in from the north.
Wednesday through Friday...The east Pacific ridge will be pushed
inland by an approaching trough of low pressure. The mainly dry
weather pattern for Wednesday will become more unsettled as the
trough moves through the Inland Northwest Thursday. As warmer air
aloft pushes into the region from the south Thursday morning there
is a threat of freezing rain for the lower basin and possibly into
the Wenatchee area as well. Thursday looks like the best bet for
some light to moderate snowfall accumulations for much of the
forecast area. Beyond Thursday, model solutions diverge with the
ECMWF allowing the ridge to quickly build back over the region while
the GFS keeps a more unsettled trough pattern over us. /Kelch
&&
.AVIATION...
12Z TAFS: An upper level trough has moved into the area overnight
and will linger through at least Sunday. This will allow the
atmosphere to destabilize and support snow showers across the
region...mainly though the afternoon and early evening. A slightly
stronger wave looks to move through the southeast zones and
may increase the intensity of the showers near KLWS/KPUW through
00z this afternoon. Otherwise showers will be isolated to
scattered. Southwest winds and lingering boundary level moisture
will allow stratus formation for the KCOE/KSFF/KGEG corridor with
conditions MVFR/IFR. Near KPUW/KLWS VFR/MVFR conditions for
localized stratus and the potential for heavier showers. Lastly
the southwest winds have backed off from yesterday...but still
expect winds 10-15 kts with gusts 20-25kts for KPUW and KGEG.
Tobin
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 27 34 26 34 24 / 20 20 20 20 20 20
Coeur d`Alene 35 27 34 27 33 26 / 30 30 40 20 20 40
Pullman 38 28 35 28 34 26 / 60 20 40 20 40 30
Lewiston 44 32 42 31 39 30 / 60 20 20 20 40 20
Colville 34 27 33 26 33 23 / 20 20 20 20 10 30
Sandpoint 34 28 33 27 32 27 / 30 30 40 30 20 40
Kellogg 33 27 31 25 31 24 / 70 40 50 30 50 50
Moses Lake 41 27 38 26 37 25 / 10 10 10 10 10 10
Wenatchee 38 29 36 27 36 27 / 10 10 10 10 10 10
Omak 34 25 32 22 32 21 / 10 20 20 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 PM CST SAT JAN 30 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 344 PM CST SAT JAN 30 2016
AT 3 PM...WATER VAPOR IMAGERY SHOWS A FAIRLY STRONG AND COMPACT
SHORT WAVE TROUGH MOVING EAST ACROSS NORTH DAKOTA. WITH THE AIR
MASS FAIRLY DRY BELOW 7K FEET...ONLY A FEW SPRINKLES ARE
ASSOCIATED WITH THIS FEATURE. THE 30.12Z MODELS ARE IN GOOD
AGREEMENT THAT THIS FEATURE WILL MOVE EAST ACROSS CENTRAL
MINNESOTA AND NORTHERN WISCONSIN THIS EVENING. THERE WILL BE
ENOUGH OF A NORTHWEST PUSH IN THE WAKE OF THIS SYSTEM TO BRING A
WEAK COLD FRONT INTO THE AREA. WE CAN ALREADY SEE SOME EVIDENCE OF
THIS FRONT OVER SOUTHWEST AND CENTRAL WISCONSIN. THE MODELS ARE IN
GOOD AGREEMENT THAT STRONG 900 TO 700 MB FRONTOGENESIS WILL
DEVELOP ALONG AND NORTH OF THE INTERSTATE 90 CORRIDOR. IN ADDITION
TO THIS...THE AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A
110 KNOT JET THIS EVENING AND EARLY OVERNIGHT. SOUNDINGS CONTINUE
TO SHOW THAT THERE CONTINUES TO BE A 2 TO 5F WARM LAYER ALOFT
SOUTH OF INTERSTATE 94. THIS WILL RESULT IN RAIN IN THIS AREA. AT
THIS TIME...IT LOOKS LIKE THE TEMPERATURES SHOULD REMAIN JUST
ABOVE FREEZING THROUGH TONIGHT AND SUNDAY MORNING. HOWEVER IF THE
TEMPERATURES HAPPEN TO FALL TO FREEZING...WE MAY HAVE TO CONTEND
WITH SOME LIGHT FREEZING RAIN IN SOUTHEAST MINNESOTA AND NORTH
CENTRAL WISCONSIN. ALSO IF THERE IS ENOUGH EVAPORATIVE COOLING
NORTH OF INTERSTATE 94...THERE MAY BE SOME LIGHT SNOW. WITH THE
MODELS BEING IN FAIRLY GOOD AGREEMENT THAT THIS SYSTEM WILL BE
EXITING THE AREA DURING THE MORNING...LOWERED THE PRECIPITATION
CHANCES DURING THE EARLY AFTERNOON...AND KEPT MOST AREAS DRY
DURING THE MID AND LATE AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 344 PM CST SAT JAN 30 2016
THE MAIN CONCERN DURING THIS TIME PERIOD CONTINUES TO BE FROM
TUESDAY THROUGH WEDNESDAY. THE OPERATIONAL GFS...GEM...AND ECMWF
CONTINUE TO SUGGEST THAT THE SURFACE LOW WILL LIKELY TRACK FROM
KANSAS CITY TO CHICAGO AND THEN NORTHEAST INTO NORTHERN LOWER
MICHIGAN AND EASTERN UPPER MICHIGAN. WITH THIS TRACK...SOUNDINGS
CONTINUE TO SUGGEST THAT THE AREA WILL BE COLD ENOUGH ALOFT FOR
PRETTY MUCH THE ENTIRE AREA TO SEE ONLY SNOW FROM THIS SYSTEM. THE
LONE EXCEPTION MAYBE IN FAR SOUTHWEST WISCONSIN WHERE THE BOUNDARY
LAYER TEMPERATURES MAY WARM ENOUGH THAT THERE COULD BE A BRIEF MIX
OF RAIN OR A WINTRY MIX. WHILE THERE IS GOOD AGREEMENT AMONGST
MOST OF THE MAJOR OPERATIONAL MODELS ON THE TRACK OF THIS
SYSTEM...THE NAM AND MANY MEMBERS OF CANADIAN ENSEMBLE HAVE A
FURTHER SOUTHEAST TRACK. MANY OF THE EASTERN AND SOUTHERN
SOLUTIONS HAVE A MUCH WEAKER WAVE COMING OUT OF THE SOUTHWEST
UNITED STATES. ANOTHER ISSUE THAT WE MIGHT HAVE TO CONTEND WITH IS
HOW MUCH THE CONVECTION ALONG THE COLD FRONT MIGHT LIMIT SOME OF THE
MOISTURE IN THE DEFORMATION AREA. THE LAST 5 GFS RUNS OF COBB DATA
HAS BEEN CONSISTENTLY IN THE 10 TO 15 INCH RANGE. MEANWHILE IN
ROCHESTER...IT WAS AROUND 15 INCHES ON FRIDAY...BUT IN THE LAST 2
MODEL RUNS IT HAS DECREASED INTO THE 6 TO 8 INCH RANGE. THE REASON
FOR THE DIFFERENCE IN THAT THE WARM CONVEYOR BELT HAS SHIFTED JUST
A BIT FURTHER EAST AND THIS IS ALLOWING THE DRIER AIR ASSOCIATED
WITH THE COLD CONVEYOR BELT TO MOVE INTO THE AREA FASTER. USING
THE CURRENT PRECIPITATION TOTALS AND SNOW TO LIQUID RATIOS IN THE
10-15 TO 1 RANGE...THE PRELIMINARY SNOW TOTALS IN THE FORECAST
GRIDS FOR TUESDAY ARE 2 TO 5 INCHES NORTH OF INTERSTATE 94 AND 5
TO 10 INCHES ACROSS THE REMAINDER OF THE FORECAST AREA. AN
ADDITIONAL 2 TO 4 INCHES LOOK POSSIBLE FOR TUESDAY NIGHT. THIS
WOULD RESULT IN A TOTAL OF 8 TO 13 INCHES OF SNOW. THESE SNOW
TOTALS WILL BE HIGHLY DEPENDENT UPON THE FINAL TRACK OF THIS
SYSTEM...SO THEY WILL LIKELY FLUCTUATE BETWEEN NOW AND TUESDAY.
SINCE THIS SYSTEM IS NOT ONSHORE YET AND NOT BEING WELL SAMPLED
BY THE UPPER AIR NETWORK...THERE IS STILL THE POTENTIAL THAT THIS
TRACK COULD STILL SHIFT. DUE TO THIS...THE CONSENSUS WAS TO WAIT
ON ISSUING A WINTER STORM WATCH FOR NOW.
IN ADDITION TO THE SNOW...THERE IS CONCERN ABOUT THE STRONG
SURFACE PRESSURE GRADIENT THAT DEVELOPS ACROSS SOUTHERN MINNESOTA
AND NORTHEAST IOWA. THIS COULD RESULT IN SUSTAINED WIND OF 20 TO
30 MPH AND GUSTS UP TO 35 MPH. THIS COULD RESULT IN CONSIDERABLE
BLOWING AND DRIFTING FROM LATE TUESDAY AFTERNOON INTO WEDNESDAY
MORNING.
THOSE WITH TRAVEL PLANS FROM THE CENTRAL PLAINS INTO THE NORTHERN
GREAT LAKES EARLY NEXT WEEK SHOULD CONTINUE TO MONITOR FUTURE
FORECASTS CLOSELY THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1116 AM CST SAT JAN 30 2016
WATCHING A SHORT WAVE TROUGH MOVING INTO THE WESTERN DAKOTAS LATE
THIS MORNING. WARM AIR ADVECTION ZONE AHEAD OF THIS WAVE IS
CAUSING SOME RADAR RETURNS OVER SOUTHWEST MINNESOTA...BUT SO
FAR...ONLY MID LEVEL CLOUDS ARE BEING REPORTED FROM THIS AREA. THE
30.16Z HRRR SUGGESTS THIS AREA OF RETURNS WILL CONTINUE TO
STRENGTHEN THROUGH THE AFTERNOON WITH SOME LIGHT RAIN OR SPRINKLES
POSSIBLE AT KRST BEFORE 00Z. LOOKING AT THE RAP BUFKIT SOUNDINGS
FOR THIS TIME FRAME...THERE IS STILL A LOT OF LOW LEVEL DRY AIR IN
PLACE AND WOULD NOT EXPECT MUCH MORE THAN SPRINKLES IF IT DOES
MOVE IN THIS AFTERNOON. OTHERWISE...THE TIMING FOR THE LIGHT RAIN
TO MOVE IN FROM OTHER 30.12Z MODELS IS EARLY THIS EVENING. THE
FORCING FROM THIS WAVE DOES NOT LOOK TO BE VERY STRONG SO
EXPECTING LITTLE OR NO VISIBILITY RESTRICTIONS TO OCCUR WITH
MAINLY VFR CEILINGS. THE EXCEPTION TO THAT MAY BE LATE TONIGHT AT
KLSE IF THE COLUMN CAN COOL ENOUGH TO SUPPORT A RAIN/SNOW MIX.
HAVE PUT IN A PERIOD OF MVFR CONDITIONS OVERNIGHT TO COVER THIS
POSSIBILITY. LOOKS LIKE ALL THE PRECIPITATION SHOULD END EARLY
SUNDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 259 PM CST SAT JAN 30 2016
A WEAK COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION LATER
TONIGHT INTO SUNDAY MORNING. A WAVE IS EXPECTED TO MOVE ALONG THE
FRONT LATE TONIGHT AND SUNDAY...BRINGING A SWATH OF PRECIPITATION
TO PORTIONS OF THE FORECAST AREA LATER THIS EVENING INTO SUNDAY
AFTERNOON.
MANY ISSUES TO CONTEND WITH TODAY WITH RESPECT TO PRECIPITATION
TYPES LATER TONIGHT. TEMPERATURES THIS AFTERNOON CLIMBED INTO
THE 40S AT MOST PLACES. THE LAST CHECK OF ROAD TEMPERATURES
WERE WELL INTO THE 40S TO AROUND 50. ALSO...THE OTHER MAJOR
PROBLEM WILL BE IF THERE WILL BE PRECIPITATION WILL IT WILL
GET COLD ENOUGH FOR MIXED PRECIPITATION.
MOST OF THE MODELS HAVE PRECIPITATION MOVING INTO PORTIONS OF
NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN LATER TONIGHT.
HOWEVER...THE LATEST HRRRR AND RAP MODELS DO NOT PRODUCE
PRECIPITATION INTO THIS REGION WHERE IT WOULD GET COLD ENOUGH
FOR FREEZING RAIN...SLEET OR SNOW. CONTEMPLATED ISSUING A WINTER
WEATHER ADVISORY FOR MARATHON UP THROUGH NORTHERN MARINETTE
COUNTY...BUT THE FACT THE MESO MODELS DO NOT PRODUCE PRECIPITATION
MADE ME HOLD OFF ON ISSUING AN ADVISORY. IF THE GFS/ECMWF IS
CORRECT...THERE MAY BE A PERIOD LATE TONIGHT FOR SOME FREEZING
RAIN...SLEET OR SNOW THAT COULD MAKE ROADS SLICK.
THE WAVE IS EXPECTED TO MOVE EAST OF THE AREA ON SUNDAY. THE
PRECIPITATION SHOULD COME TO AN END SUNDAY AFTERNOON OR EVENING.
WENT WITH THE THREE HOURLY TEMPERATURES ON GUIDANCE FOR LOWS
AND CLOSER TO THE MAV GUIDANCE. HIGHS ON SUNDAY WILL BE IN THE
30S AGAIN.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 259 PM CST SAT JAN 30 2016
THE MID LEVEL TROUGH WILL CONTINUE TRACKING AWAY FROM WISCONSIN
SUNDAY NIGHT...ENDING PRECIPITATION FROM WEST TO EAST AS
PRECIPITATION CHANGES OVER TO ALL SNOW ACROSS THE EASTERN CWA BY
THE EVENING HOURS. NORTH NORTHWESTERLY WINDS ON THE BACKSIDE OF
THE LOW WILL BRING LAKE EFFECT SHOWERS TO THE LAKE SUPERIOR
SNOWBELT REGION ON MONDAY AND MONDAY NIGHT.
THE MAIN FOCUS IN THE LONG TERM CONTINUES TO BE THE LOW HEADING
FOR THE GREAT LAKES TUESDAY AND WEDNESDAY. DESPITE THE PRIOR 00Z
MODEL RUNS...THE 12Z SUITE OF RUNS HAS COME INTO BETTER AGREEMENT
REGARDING THE TIMING AND TRACK OF THE LOW. THE LONE EXCEPTION IS
THE VERY SLOW NAM WHICH HAS MOST OF THE CWA DRY THROUGH TUESDAY
AFTERNOON. GIVEN EVEN THE PREVIOUSLY SLOWER CANADIAN HAS LATCHED
ONTO THIS FASTER SOLUTION WHICH BRINGS THE HEAVY SNOW INTO THE
AREA BY TUESDAY AFTERNOON...WILL PUT SOME RESOLUTION INTO THE
TUESDAY POP GRID AND GO WITH LOWER POPS IN THE MORNING...AND RAMP
THEM UP IN THE AFTERNOON. IN ADDITION TO THE SNOW...THE VERY TIGHT
PRESSURE GRADIENT WILL CAUSE BLOWING AND DRIFTING OF SNOW ACROSS
THE FORECAST AREA AS MODERATE TO HEAVY SNOW GETS GOING ACROSS THE
REGION.
THE LONG RANGE MODELS TRACK THE LOW A BIT FURTHER WEST THAN
YESTERDAYS RUNS...TRACKING THE LOW OVER SOUTHERN TO CENTRAL LAKE
MICHIGAN TUESDAY NIGHT...THEN OVER LAKE HURON INTO CANADA ON
WEDNESDAY. THIS WESTWARD JOG MAKES SENSE AS THE NORTHERN STREAM
LOW OVER SOUTHERN CANADA IS CLOSE ENOUGH TO PULL THE SOUTHERN
STREAM LOW CLOSER WEST. THERE ARE STILL SOME DIFFERENCES REGARDING
THE EXACT TRACK AND TIMING...HOWEVER WITH A RELATIVELY DECENT
CONSENSUS TUESDAY NIGHT WILL RAISE POPS TO CATEGORICAL ACROSS THE
FORECAST AREA AS THE DRY SLOT LOOKS TO REMAIN JUST OFF TO THE EAST
ON TUESDAY NIGHT. THE TIGHT PRESSURE GRADIENT WILL REMAIN TUESDAY
NIGHT...WITH CONTINUED BLOWING AND DRIFTING SNOW.
THE LOW RAPIDLY TRACKS AWAY FROM THE AREA TOWARDS WESTERN QUEBEC
ON WEDNESDAY...WITH LINGERING SNOW SHOWERS AS WELL AS SIGNIFICANT
BLOWING AND DRIFTING SNOW WITH THE CONTINUED TIGHT PRESSURE
GRADIENT. THIS WILL LIKELY MAKE SNOW REMOVAL AND TRAVEL DIFFICULT
THROUGH MUCH OF WEDNESDAY. IN ADDITION A NORTH NORTHWESTERLY
COMPONENT WILL TURN ON THE LAKE SUPERIOR SNOW BELT
REGION...BOOSTING TOTALS ACROSS THAT AREA ON WEDNESDAY. OVERALL IT
LOOKS LIKE A GOOD BET FOR 6 OR MORE INCHES OF SNOW ACROSS
NORTHEAST WISCONSIN FROM TUESDAY THROUGH WEDNESDAY. THE DRY SLOT
COULD STILL PLAY A ROLE...ESPECIALLY IF THE SYSTEM TRACKS FURTHER
WEST...WHICH IS A POSSIBILITY GIVEN THE PROXIMITY TO THE NORTHERN
STREAM LOW. THE DRY SLOT WOULD TEND TO HOLD DOWN
TOTALS...THEREFORE THERE IS RECITANCE IN PUTTING MORE SOLID
SNOWFALL AMOUNTS DOWN AT THIS JUNCTURE.
BEHIND THE LOW A COLD ARCTIC AIRMASS WILL FILTER IN AS 850 MB
TEMPERATURES PLUNGE INTO THE MIDDLE TO UPPER TEENS BELOW ZERO FOR
THE LATE PART OF THE WEEK AND INTO THE EARLY PART OF NEXT
WEEKEND. SEVERAL WEAK LOW PRESSURE SYSTEMS AND LAKE EFFECT WILL
BRING SEVERAL OPPORTUNITIES FOR LIGHT SNOW AT TIMES TO THE REGION
FOR THE LATE PART OF THE WEEK AND INTO THE WEEKEND. HOWEVER THESE
SYSTEMS WILL HAVE MEAGER MOISTURE TO WORK WITH...SO SIGNIFICANT
SNOWFALL DURING THE LATE PART OF THE EXTENDED IS NOT ANTICIPATED.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1138 AM CST SAT JAN 30 2016
A WEAK COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION LATE
TONIGHT INTO SUNDAY MORNING. THIS FEATURE WILL BRING A CHANCE OF
RAIN...FREEZING RAIN...SLEET AND SNOW TO THE REGION LATE THIS
EVENING INTO SUNDAY MORNING. FOR THE FOX VALLEY AND LAKESHORE
REGION...THE PRECIPITATION SHOULD BE MAINLY RAIN. TO THE NORTH AND
WEST OF THE FOX VALLEY...A MIX OF RAIN...FREEZING RAIN...SLEET AND
SNOW IS EXPECTED DEPENDING ON BOUNDARY LAYER TEMPERATURES AND HOW
QUICK THESE BOUNDARY LAYER TEMPERATURES COOL OFF LATER TONIGHT.
WENT MORE FREEZING RAIN AND SNOW FOR THE 00Z TAFS AT
KAUW/KRHI/KCWA. THE PRECIPITATION COULD POSSIBLY STAY JUST SOUTH
OF KRHI IF SOME OF THE MODELS ARE CORRECT. ANY PRECIPITATION
SHOULD COME TO AN END BY MID AFTERNOON ON SUNDAY ACROSS NORTHEAST
WISCONSIN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ECKBERG
LONG TERM......KURIMSKI
AVIATION.......ECKBERG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1116 AM CST SAT JAN 30 2016
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 220 AM CST SAT JAN 30 2016
A COUPLE PIECES OF UPPER LEVEL ENERGY GOING TO COME TOGETHER AND
PRODUCE SOME PRECIPITATION ACROSS THE REGION LATER TONIGHT INTO
SUNDAY. FIRST PIECE OF ENERGY WILL MOVE OUT OF THE SOUTHERN
ROCKIES...LIFTING NORTHEAST ACROSS IA TO SOUTHERN WI/NORTHERN IL.
THE OTHER PIECE OF ENERGY IS MORE ELONGATED/STRONGER IN NATURE AND
WILL MOVE OUT OF THE PAC NW TO THE UPPER MISSISSIPPI RIVER VALLEY
BETWEEN 12-18Z SUN. PRETTY GOOD FRONTOGENETIC RESPONSE BETWEEN
THESE TWO UPPER LEVEL FEATURES...EVIDENCED IN A NORTHWEST-
SOUTHEAST RUNNING X-SECTION. RIGHT ENTRANCE REGION OF A 100 KT
UPPER LEVEL JET STREAK WILL ENHANCE LIFT TONIGHT. SATURATION IS
MORE TOP DOWN...SO THERE SHOULD BE ICE IN THE CLOUD.
HOWEVER...THERE IS ALSO A STRONG PUSH OF LOW LEVEL/SFC WARMING.
HIGHS WILL NEAR 40 FOR SOME TODAY...AND LIKELY STAY ABOVE FREEZING
TONIGHT FOR THE SOUTHERLY 1/2 OF THE FORECAST AREA. A FEW DEGREE
REBOUND FROM MORNING LOWS IS EXPECTED ON SUNDAY. SO PRECIPITATION
TYPE QUESTION REST ON THE SFC TEMPS/DEPTH OF THE WARM LAYER. AS IT
SITS...RAIN LOOKS TO BE THE PREDOMINANT TYPE FOR THE SOUTHERN 1/2
OF THE FORECAST AREA. MORE SNOW-RAIN/SNOW TO THE NORTH. CAN/T RULE
OUT A SHORT PERIOD OF FREEZING RAIN THOUGH...WHERE IT COOLS ENOUGH
TO SUPPORT IT. WITH A SLIGHTLY WARMER ATMOSPHERE EXPECTED...SNOW
AMOUNTS LOOK A LOT LESS COMPARED TO YESTERDAY...MOSTLY 1/2 INCH OR
LESS. OBVIOUSLY IF ITS COLDER...AN INCH OR TWO WILL BE MORE
LIKELY.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 220 AM CST SAT JAN 30 2016
OKAY. THERE IS A STORM COMING. ITS GOING TO HAVE SIGNIFICANT IMPACTS
FOR MANY. SNOW IN EXCESS OF A FOOT. CONSIDERABLY BLOWING AND
DRIFTING. BLIZZARD/NEAR BLIZZARD CONDITIONS POSSIBLE. YOU WILL HEAR
A LOT ABOUT THE STORM FROM NOW UNTIL IT MOVES IN...AND RIGHTLY SO.
BUT THERE REMAINS A LOT OF UNCERTAINTY YET IN TRACK OF THE STORM
AND ITS OVERALL EVOLUTION. CONFIDENCE IS LOW IN THESE AREAS.
CONFIDENCE HIGHER IN ITS SNOW/WIND POTENTIAL. ANTICIPATE SOME
CHANGES TO THE FORECAST AS TUE APPROACHES AND TRENDS BECOME CLEARER.
PREPARE FOR THE WORST...BE THANKFUL IF THE TRACK SHIFTS. BUT DON/T
UNDER ESTIMATE WHAT THE STORM COULD DO.
UPPER LEVEL TROUGH STILL SLATED TO SWING OUT OF THE DESERT
SOUTHWEST...DRIVING ACROSS THE PLAINS TO ACROSS THE GREAT LAKES BY
06-12Z WED. THE SFC LOW LEADS THE UPPER LEVEL LOW A BIT...MOVING
ROUGHLY OVER NORTHERN ILL BY 00Z WED. MODELS DIFFER IN
PLACEMENT...BUT AGREE WITH GENERAL AREA. ALL HAVE STRONG LOW LEVEL
THERMODYNAMICS RUNNING AHEAD OF THE STACKED LOW...WITH A VERY STRONG
RESPONSE THROUGH THE LEVELS IN QG CONVERGENCE. SUMMERY FETCH OF 850
MB MOISTURE TRANSPORT RUNNING NORTHWARD ALONG THE SYSTEM/S COLD
FRONT. MUCH OF THAT WILL BE USED FOR CONVECTIVE LINE ASSOCIATED WITH
THE FRONT...BUT AMPLE/DEEP SATURATION MOVES NORTH-WEST INTO THE
STORM/S DEFORMATION REGION. 150+ KT 300 MB JET GOING TO ENHANCE THE
ALREADY STRONG LIFT TUE PER ITS LEFT EXIT REGION...WHICH IS
CURRENTLY PROGGED TO MOVE RIGHT ACROSS THE LOCAL FORECAST AREA. ITS
PACKING A PUNCH...NO DOUBT.
GFS COBB OUTPUT HAS LAID OUT AROUND A FOOT OR GREATER FOR LA CROSSE
OVER ITS LAST 4 RUNS. CERTAINLY DOABLE WITH THAT FORCING...AND...AND
IF THE TRACK SLIDES THE DEFORMATION AXIS ACROSS THE REGION...WHICH
IT HAS BEEN DOING. IT LOOKS TO BE ALL OR NEARLY ALL SNOW FOR
PRECIPITATION TYPE. DEPENDING ON WHERE THE LOW ENDS UP...SOME
RAIN COULD MIX IN FOR THE SOUTHEAST/EAST PORTIONS OF THE FORECAST
AREA. FOR WIND...SFC GRADIENT TIGHTENING UP AS THE LOW
STRENGTHENS/MOVES IN. SUSTAINED 20 KTS WITH GUSTS IN THE MID 30S
REASONABLE IN THE OPEN/UNSHELTERED AREAS. A LOT OF
BLOWING/DRIFTING WOULD RESULT...WITH THE POTENTIAL FOR WHITE-OUT
CONDITIONS. TRAVEL COULD/WOULD BECOME IMPOSSIBLE/DANGEROUS IN THIS
SCENARIO. THERE WOULD BE ROAD CLOSURES.
WINTER STORM WATCHES AND/OR BLIZZARD WATCHES ARE STILL LIKELY FOR
TUE/TUE NIGHT...UNLESS THERE ARE CONSIDERABLE CHANGES IN THE
TRACK/STRENGTH OF THIS WINTER STORM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1116 AM CST SAT JAN 30 2016
WATCHING A SHORT WAVE TROUGH MOVING INTO THE WESTERN DAKOTAS LATE
THIS MORNING. WARM AIR ADVECTION ZONE AHEAD OF THIS WAVE IS
CAUSING SOME RADAR RETURNS OVER SOUTHWEST MINNESOTA...BUT SO
FAR...ONLY MID LEVEL CLOUDS ARE BEING REPORTED FROM THIS AREA. THE
30.16Z HRRR SUGGESTS THIS AREA OF RETURNS WILL CONTINUE TO
STRENGTHEN THROUGH THE AFTERNOON WITH SOME LIGHT RAIN OR SPRINKLES
POSSIBLE AT KRST BEFORE 00Z. LOOKING AT THE RAP BUFKIT SOUNDINGS
FOR THIS TIME FRAME...THERE IS STILL A LOT OF LOW LEVEL DRY AIR IN
PLACE AND WOULD NOT EXPECT MUCH MORE THAN SPRINKLES IF IT DOES
MOVE IN THIS AFTERNOON. OTHERWISE...THE TIMING FOR THE LIGHT RAIN
TO MOVE IN FROM OTHER 30.12Z MODELS IS EARLY THIS EVENING. THE
FORCING FROM THIS WAVE DOES NOT LOOK TO BE VERY STRONG SO
EXPECTING LITTLE OR NO VISIBILITY RESTRICTIONS TO OCCUR WITH
MAINLY VFR CEILINGS. THE EXCEPTION TO THAT MAY BE LATE TONIGHT AT
KLSE IF THE COLUMN CAN COOL ENOUGH TO SUPPORT A RAIN/SNOW MIX.
HAVE PUT IN A PERIOD OF MVFR CONDITIONS OVERNIGHT TO COVER THIS
POSSIBILITY. LOOKS LIKE ALL THE PRECIPITATION SHOULD END EARLY
SUNDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04