Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/22/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
815 PM MST WED JAN 21 2015
.SYNOPSIS...A STORM SYSTEM PASSING THE STATE WILL CONTINUE TO BRING
SOME SHOWERS TO THE AREA EAST AND NORTH OF TUCSON TONIGHT. A SECOND
SYSTEM WILL DROP SOUTH ALONG THE NEW MEXICO BORDER BY THURSDAY
DRIVING MUCH COOLER AND DRIER AIR ACROSS THE AREA THURSDAY INTO
FRIDAY. TEMPERATURES WILL WARM TO ABOVE NORMAL LEVELS AGAIN OVER THE
WEEKEND UNDER MOSTLY CLEAR SKIES...THEN ANOTHER STORM SYSTEM MAY
BRING SHOWERS TO THE REGION THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...SHORTWAVE ENERGY CONTINUES TO MOVE THRU THE AREA THIS
EVENING. RAP AROUND MOISTURE ASSOCIATED WITH THIS SYSTEM HAS BROUGHT
SOME LIGHT SHOWERS TO THE AREAS NORTH AND EAST OF TUCSON. THESE
SHOWERS WILL CONTINUE TO SLIDE OFF TO THE SOUTHEAST DURING THE
OVERNIGHT. THEN SECONDARY ENERGY SLIDES DOWN...WHICH WILL HELP
MAINTAIN SOME SHOWER ACTIVITY OUT EAST. PREVIOUS FORECAST HANDLED
THIS WELL...THOUGH HAVE REMOVED POPS FROM SOUTHEASTERN ZONES THIS
EVENING. THEN THINGS WILL DRY OUT THRU THE WEEKEND BEFORE A CUTOFF
LOW BRINGS A RETURN TO SOME MOISTURE EARLY NEXT WEEK.
&&
.AVIATION...VALID THRU 23/00Z.
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. CLOUD
CEILINGS AROUND 10-15K FT AGL WITH LIGHT SHOWERS POSSIBLE...MAINLY
WELL NORTH AND EAST OF TUCSON TONIGHT AND EARLY THURSDAY. SURFACE
WIND WESTERLY 10 TO 15 KTS WITH OCCASIONAL GUSTS TO 25 KTS BEFORE
SUNDOWN THIS EVENING. LOCALLY GUSTY SURFACE WIND AGAIN THURSDAY
AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A CHANCE OF RAIN AND MOUNTAIN SNOW SHOWERS WILL
EXIST THROUGH THURSDAY ACROSS AREAS TO THE NORTH AND EAST OF TUCSON.
BREEZY SOUTHWESTERLY EARLY THIS EVENING. SLIGHTLY ABOVE NORMAL
TEMPERATURES TODAY WILL BE FOLLOWED BY A COOLING TREND WITH HIGHS
DROPPING TO ROUGHLY 4 TO 8 DEGREES BELOW NORMAL THURSDAY AND FRIDAY.
THEREAFTER...DRY CONDITIONS AND ANOTHER WARMING TREND ARE EXPECTED
THROUGH THE WEEKEND. A PERSISTENT EASTERLY WIND WILL SET UP THURSDAY
NIGHT AND INTO THE WEEKEND WITH LOCALLY GUSTY CONDITIONS NEAR
FAVORED MOUNTAIN GAPS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
304 PM PST TUE JAN 20 2015
.SYNOPSIS...
THE SAN JOAQUIN VALLEY WILL SEE A CONTINUATION OF COOL WEATHER UNDER
MOSTLY CLOUDY SKIES ALONG WITH NIGHT AND MORNING FOG. CONDITIONS
OUTSIDE THE VALLEY WILL SEE PARTLY CLOUDY SKIES WITH ABOVE NORMAL
TEMPERATURES.
&&
.DISCUSSION...ABUNDANT HIGH CLOUDS WERE PRESENT OVER THE REGION
THIS AFTERNOON AS AN UPPER TROUGH MOVED SOUTHEAST THROUGH THE AREA
TODAY. MUCH OF THE SAN JOAQUIN VALLEY REMAINS IN A THICK LAYER OF
STRATUS...APPROXIMATELY 1500 FEET DEEP ACCORDING TO THE VISALIA
PROFILER. ADDITIONALLY...PATCHY DRIZZLE WAS REPORTED THROUGH PARTS
OF THE VALLEY. A FEW LOCATIONS IN THE VALLEY REPORTED
DRIZZLE...WITH TULARE...HURON...AND KETTLEMAN HILL ACTUALLY
MEASURING 0.01" OF PRECIPITATION. WITH ABUNDANT CLOUD COVER OVER
THE VALLEY...THERE HAS BEEN VERY LITTLE DIURNAL TEMPERATURE
CHANGE...WITH HIGH TEMPERATURES IN THE UPPER 40S TO LOW 50S AND
OVERNIGHT LOW TEMPERATURES IN THE MID 40S.
THE UPPER TROUGH WILL SHIFT EAST OUT OF THE AREA LATE TONIGHT INTO
EARLY TOMORROW MORNING ALLOWING HIGH PRESSURE TO BRIEFLY BUILD
OVER THE REGION. UNFORTUNATELY THIS WILL DO LITTLE TO NOTHING TO
THE VALLEY STRATUS. THE HIGH RES ARW...HIGH RES NMM...AND HRRR ALL
INDICATE PATCHY DRIZZLE ONCE AGAIN OVER THE VALLEY TONIGHT...WITH
THE ARW AND NMM SHOWING DRIZZLE THROUGH AT LEAST THURSDAY MORNING.
WITH STRATUS FIRMLY IN PLACE...THE TEMPERATURE FORECAST WILL BE A
NEARLY COOKIE CUTTER FROM DAY TO DAY.
ANOTHER UPPER TROUGH WILL MOVE SOUTHEAST TOWARD THE REGION ON
THURSDAY. THE HIGH RES MODELS INDICATE A DRYING OF THE BOUNDARY
LAYER...POSSIBLY ERODING THE STRATUS LAYER. HOWEVER CONFIDENCE IS
LOW AND THE LOW CLOUDS REMAIN IN THE FORECAST. WE WILL CONTINUE TO
MONITOR MODEL TRENDS AND HOPEFULLY GET A BETTER HANDLE OF THE
SITUATION IN THE NEXT 24 HOURS.
OTHERWISE...INTERESTING WEATHER PATTERN SETS UP OVER THE WEEKEND
INTO EARLY NEXT WEEK. AN UPPER RIDGE WILL BE PRESENT OVER
CALIFORNIA WITH A CLOSED UPPER LOW OVER THE SOUTHEASTERN PACIFIC
RESULTING IN A REX BLOCK. AN UPPER TROUGH IN THE EASTERN PACIFIC
WILL SHIFT EAST TOWARD THE REGION MONDAY INTO TUESDAY...WITH THE
UPPER LOW MOVING NORTHEAST. THERE ARE HUGE DISCREPANCIES BETWEEN
THE OPERATIONAL MODELS...THE ENSEMBLE MEANS...AND THE MODEL TRENDS
WITH THE MOVEMENT OF THIS LOW. THERE IS THE POSSIBILITY OF RAIN
MOVING NORTH INTO KERN COUNTY EARLY NEXT WEEK...CONTINUING NORTH
THROUGH THE REST OF THE AREA INTO THE MIDDLE OF THE WORK WEEK. A
SLIGHT CHANCE OF RAIN HAS BEEN ADDED TO THE FORECAST FOR THIS TIME
FRAME...AS NCEPS RELATIVE MEASURE OF PREDICIBILITY IS INDICATING
MEDIUM CONFIDENCE FOR THE UPPER PATTERN. PLEASE CONTINUE TO
MONITOR THE FORECAST FOR THE LATEST INFORMATION.
&&
.AVIATION...
IFR VISIBILITIES WILL PREVAIL IN THE SAN JOAQUIN VALLEY DURING THE
NEXT 24 HOURS WITH LOCAL LIFR/VLIFR VISIBILITIES IN DRIZZLE AND FOG
UNTIL 20Z WEDNESDAY. VFR CONDITIONS CAN BE EXPECTED ELSEWHERE ACROSS
THE CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...
ON TUESDAY JANUARY 20 2015... FIREPLACE/WOOD STOVE BURNING STATUS
IS: NO BURNING UNLESS REGISTERED IN FRESNO... KERN... KINGS...
MADERA... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS MEDIUM.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 01-20 72:1994 36:1937 55:1901 24:1963
KFAT 01-21 72:1994 39:1937 56:1896 19:1937
KFAT 01-22 70:1994 35:1962 52:1888 25:1945
KBFL 01-20 77:1912 40:1940 56:1969 21:1922
KBFL 01-21 79:1981 40:1937 60:1942 19:1937
KBFL 01-22 76:1981 38:1962 60:1981 19:1937
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...RILEY
AVN/FW...ANDERSEN
SYNOPSIS...JDB
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
957 AM MST TUE JAN 20 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 331 AM MST TUE JAN 20 2015
LAST EVENING`S PROGRESSIVE SHORTWAVE TROUGH WAS QUICKLY EXITING INTO
THE CENTRAL PLAINS EARLY THIS MORNING BUT FAVORABLE NW OROGRAPHIC
FLOW AND THE NOSE OF A TRAILING UPPER JET SHOULD KEEP SNOW OVER THE
NAN AND CNTL CO MTNS NEARER THE DIVIDE UNTIL ABOUT SUNRISE PER
THE 08Z HRRR MODEL. WILL CONTINUE THE WINTER WEATHER ADVISORY FOR
THE VAIL PASS AREA THOUGH IT MAY BE A BIT LONG IN DURATION. FOG
PERSISTS IN THE EASTERN UINTA BASIN WHERE A DENSE FOG ADVISORY
CONTINUES.
FOG ALSO DEVELOPED IN THE GUNNISON AREA EARLY THIS MORNING FOLLOWING
SOME LIGHT SNOW LAST EVENING. FOG WAS QUITE NOTICEABLE ON THE
WSCU CAMPUS WEBCAM IN GUNNISON. THE GUNNISON AIRPORT OBSERVATION
HAS BEEN DOWN TO 1/4 MILE VISIBILITY AT TIMES...AND RAP FORECAST
SOUNDING INDICATED FOG TO PERSIST THIS MORNING. ISSUED A DENSE
FOG ADVISORY FOR THE UPPER GUNNISON RIVER VALLEY.
CONTINUED DRYING OF THE AIRMASS SHOULD LEAD TO PARTLY TO MOSTLY
SUNNY SKIES ACROSS MOST OF THE FORECAST AREA THIS AFTERNOON. DO NOT
SEE MUCH MIXING FOR THE EASTERN UINTA BASIN TODAY SO WILL CARRY HAZE
AND SOME CLOUDS THERE THIS AFTERNOON THEN PATCHY FOG AGAIN TONIGHT.
A PACIFIC TROUGH APPROACHING THE NAN CA COAST WILL DEEPEN AND
DROP DOWN INTO THE SOUTHWEST BY WED MORNING WHILE ANOTHER
SHORTWAVE DISTURBANCE MOVES DOWN THE EAST SIDE OF THE ROCKIES. 400
MB POTENTIAL VORTICITY SHOW THESE TWO TROUGHS PHASING WITH THE
RESULTING TROUGH AXIS STRETCHING FROM THE UPPER MIDWEST ACROSS THE
FOUR CORNERS AND AZ BY LATE WED. MODELS AGREE ON A PRECIPITATION
BAND DEVELOPING JUST TO OUR SOUTH ACROSS NAN AZ/NAN NM...THOUGH
THEY HAVE BEEN KNOWN TO PLACE IT NORTHWARD IN EARLIER MODEL RUNS.
WILL MAKE LITTLE CHANGE TO THE CURRENT FORECAST OF A CHANCE OF
SNOW FOR THE SAN JUANS AND SOUTHWARD WED WITH A FEW POCKETS OF
LIGHT SNOW OVER THE CENTRAL MTNS IN COOLER BUT WEAK NORTHERLY
FLOW. NE UT AND NW CO LOOK MOSTLY SUNNY ON WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 331 AM MST TUE JAN 20 2015
THE FOCUS OF PRECIP WILL CONTINUE TO DROP SOUTH OVERNIGHT
WEDNESDAY AND THOUGH BEST CHANCES FOR PRECIP WILL BE IN NM...SOME
SHOWERS WILL LIKELY CONTINUE FOR THE SAN JUANS AND CENTRAL MTNS.
NOT MUCH IN THE WAY OF ACCUMULATION THOUGH AS THE ATMOSPHERE
REMAINS RELATIVELY DRY. MADE MINIMAL CHANGES TO GOING FORECAST AS
THIS IS CAPTURED WELL.
WHILE THE FORCING FOR PRECIP LOOKS TO BE A DEFORMATION ZONE...A
RELATIVELY WEAK AND DRY COLD FRONT WILL ALSO AID IN SOME LIFT.
HOWEVER...WITH LITTLE MOISTURE TO WORK WITH THE ONLY REAL SENSIBLE
WX FELT WILL BE COLD TEMPS. MOS GUIDANCE SHOWS HI TEMPS DROPPING
WEDNESDAY AND THURSDAY BEFORE REBOUNDING FRIDAY AND BEYOND. LOW
TEMPS FOR MANY LOCATIONS WILL BE IN THE SINGLE DIGITS TO SUBZERO
RANGE THURSDAY AND FRIDAY MORNING WHICH CERTAINLY SEEMS REASONABLE
AS NORTHERLY FLOW USHERS IN MUCH COLDER AIR TO THE REGION.
BY THURSDAY NIGHT...THE FRONT AND TROUGH WILL HAVE SHIFTED WELL
TO THE SOUTH AS FLOW BECOMES MORE NWLY. A LARGE AREA OF HIGH
PRESSURE WILL THEN BEGIN TO BUILD IN TO THE DESERT SW AS WEAK
WAVES START TO DROP DOWN FROM THE PACNW. SOME LIGHT PRECIP IS
POSSIBLE FOR THE NAN MTNS FRIDAY NIGHT WITH COVERAGE INCREASING A
BIT SUNDAY INTO MONDAY. WHILE NOTHING TOO IMPRESSIVE YET...THESE
TYPES OF LITTLE SYSTEMS SOMETIMES HAVE A HABIT OF DROPPING A QUICK
FEW INCHES OF SNOW. BLENDED GUIDANCE NOT IMPRESSED EITHER WITH SLT
CHC SNOW FOR THOSE TIMES WHICH SEEMS REASONABLE FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 955 AM MST TUE JAN 20 2015
STATUS AND FOG CONTINUE TO PLAGUE FLIGHT OPERATIONS AT KVEL AND
KDRO WITH IFR IN CONTROL THIS MORNING. WEB CAMS INDICATE THIS IS
VERY LOCALLIZED TO THE AIRFIELDS AND SOME IMPROVEMENT IS LIKELY BY
MID AFTERNOON. KASE AND KEGE ARE VFR BUT REMAIN UNDER ILS AS CIGS
HOOVER AROUND 4-5KFT AGL. AGAIN IMPROVEMENT IS EXPECTED HERE AS
WELL. VFR CONDITIONS SHOULD PREVAIL AT THESE LOCATIONS OVER THE
NEXT 24 HOURS AND WILL BE MONITORING SATELLITE TREND FOR KVEL AND
KDRO. PERSISTENCE WOULD DICTATE KVEL WILL BE IN IFR/LIFR AGAIN
TONIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...DENSE FOG ADVISORY UNTIL NOON MST TODAY FOR COZ014.
UT...DENSE FOG ADVISORY UNTIL NOON MST TODAY FOR UTZ024.
&&
$$
SHORT TERM...JAD
LONG TERM...TGR
AVIATION...15
AREA FORECAST DISCUSSION
NWS ALBANY NY
1005 PM EST WED JAN 21 2015
.SYNOPSIS...
A CLIPPER LOW PRESSURE SYSTEM WILL MOVE EASTWARD ACROSS PENNSYLVANIA
AND NEW JERSEY TONIGHT...WHICH MAY BRING SOME LIGHT SNOW TO PORTIONS
OF THE EASTERN CATSKILLS...MID HUDSON VALLEY AND NORTHWESTERN
CONNECTICUT. THE WEAK LOW WILL MERGE WITH A STRONGER LOW OFFSHORE ON
THURSDAY...AND TRACK NORTHEASTWARD WELL AWAY FROM THE REGION. HIGH
PRESSURE WILL BUILD IN FROM THE WEST THURSDAY AFTERNOON AND IS
EXPECTED TO DOMINATE OUR WEATHER THROUGH FRIDAY. A DEVELOPING
NOR`EASTER MAY AFFECT AREAS MAINLY SOUTH AND EAST OF ALBANY ON
SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 930 PM EST...REGIONAL RADAR REVEALS AN INCREASE IN ECHOES
ACROSS THE WESTERN MOHAWK VALLEY...CATSKILLS AND MID HUDSON VALLEY.
HOWEVER...OUR 00Z SOUNDING WAS QUITE DRY BELOW H700 SO A LOT OF THIS
LIGHT SNOW IS LIKELY NOT REACHING THE GROUND. HRRR AND RAP13
SUGGEST THE WEAK WAVE ALOFT WILL MOVE ACROSS THE CWA AND BUFR
PROFILES SUGGEST THE LOWER LEVELS WILL SATURATE ENOUGH FOR A LITTLE
LIGHT SNOW/FLURRIES SO WE HAVE EXPANDED THE POPS SLIGHTLY TO THE
NORTH. DUE TO THE CLOUD COVERAGE...HAVE ADJUSTED TEMPERATURES
SLIGHTLY WITH A NEARLY STEADY VALUES OVERNIGHT.
PREV DISC...
CLOUDS WILL CONTINUE TO INCREASE AND THICKEN THIS
EVENING...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE AREA
ASSOCIATED WITH A CLIPPER LOW ADVANCING EAST ACROSS PA. ANY REAL
ACCUMULATING SNOW AND SIGNIFICANT SNOWFALL RATES WILL REMAIN SOUTH
OF OUR REGION. HOWEVER...ON THE NORTHERN PERIPHERY THERE COULD BE
SOME LIGHT SNOW FOR AREAS SOUTH OF THE CAPITAL DISTRICT LATER THIS
EVENING INTO THE OVERNIGHT HOURS. LIMITED FORCING AND MOISTURE
ALONG THE NORTHERN EDGE OF THIS SYSTEM WILL ENSURE VERY MINOR
ACCUMULATIONS OF GENERALLY A HALF INCH OR LESS. WILL MENTION
CHANCE POPS FOR THE LIGHT SNOW FOR THE WESTERN MOHAWK
VALLEY...SCHOHARIE VALLEY...EASTERN CATSKILLS...MID HUDSON
VALLEY...SOUTHERN TACONICS AND LITCHFIELD HILLS.
ELSEWHERE IT WILL BE MOSTLY CLOUDY AND NOT AS COLD AS LAST
NIGHT...WITH MIN TEMPERATURES RUNNING VERY CLOSE TO NORMAL FOR THIS
TIME OF YEAR. GENERALLY TEENS EXPECTED FOR MUCH OF THE AREA...EXCEPT
COLDER SINGLE DIGITS FOR THE WESTERN/SOUTHERN ADIRONDACKS AND LAKE
GEORGE AREA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
THE CLIPPER WILL MOVE OFF SHORE THURSDAY MORNING AND MERGE WITH A
DEEPENING CYCLONE WELL EAST OF NEW ENGLAND. SO OTHER THAN A SLIGHT
CHANCE OF SPOTTY LINGERING LIGHT SNOW SHOWERS ACROSS SOUTHERN
AREAS...IT SHOULD BE DRY ACROSS THE REGION. HIGH PRESSURE WILL START
TO RIDGE IN FROM THE MIDWEST DURING THE AFTERNOON. SUBSIDENCE
ASSOCIATED WITH THE RIDGE SHOULD RESULT IN GRADUALLY DECREASING
CLOUDS...ESPECIALLY DURING THE AFTERNOON HOURS. A WESTERLY BREEZE
WILL ALSO DEVELOP...WHICH WILL HELP AID IN MIXING. COMBINED WITH
SOME DEVELOPING SUNSHINE SHOULD RESULT IN TEMPS WARMING TO THE LOWER
TO MID 30S IN THE HUDSON VALLEY AND LITCHFIELD CT...WITH MID TO
UPPER 20S ACROSS THE HIGHER TERRAIN.
HIGH PRESSURE WILL RESULT TO OUR SOUTH FRIDAY NIGHT...WITH SURFACE
RIDGING EXTENDING INTO THE NORTHEAST CONUS. THIS WILL RESULT IN A
TRANQUIL NIGHT WITH SEASONABLE TEMPERATURES. WITH W-NW FLOW ALOFT
INCREASING AND SOMEWHAT COLDER AIR ADVECTING IN...THERE COULD BE
SOME LAKE ENHANCED CLOUD COVER AND MAYBE A STRAY SNOW SHOWER IN
HERKIMER COUNTY. ANOTHER DRY DAY IS EXPECTED ON FRIDAY UNDER
WESTERLY FLOW REGIME WITH SEASONABLE TEMPERATURES. THERE COULD BE
SOME ADDED CLOUD COVER ACROSS NORTHERN ZONES...BUT OVERALL PARTLY TO
MOSTLY SUNNY SKIES SHOULD PREVAIL.
QUIET CONDITIONS ARE EXPECTED FRIDAY NIGHT AS OUR REGION WILL BE
BETWEEN SYSTEMS TO THE NORTH AND SOUTH. HOWEVER...WE WILL BE
WATCHING A DEVELOPING MILLER TYPE-A COASTAL STORM ALONG THE
SOUTHEAST COAST...WHICH WILL START TO MAKE THE TURN NORTHEASTWARD
LATE FRIDAY NIGHT. ANY MOISTURE SHOULD REMAIN SOUTH OF THE REGION
THROUGH SUNRISE SATURDAY...ALTHOUGH WILL MENTION SLIGHT CHANCE POPS
ACROSS FAR SOUTHERN ZONES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WE CONTINUE TO MONITOR TRENDS FOR COASTAL STORM DEVELOPMENT AND ITS
EVENTUAL TRACK/IMPACT TO THE REGION.
WE PLACED EMPHASIS ON THE WEEKEND EVENT AS A STRONG SOUTHERN STREAM
STORM WILL INTERACT WITH A DIGGING NORTHERN STREAM TROUGH THROUGH
THE GREAT LAKES REGION. CONFIDENCE INCREASES THAT THESE TWO SYSTEMS
WILL PHASE EITHER ALONG OR JUST OFFSHORE THE MID-ATLANTIC ON
SATURDAY. THESE MILLER TYPE-A STORMS ARE USUALLY ASSOCIATED WITH
HIGH MOISTURE CONTENT COMING OUT OF THE GULF SO THE POTENTIAL FOR A
HEAVY QPF EVENT REMAINS A THREAT. THE LATEST GFS/ECMWF/GGEM ARE IN
RATHER EXCELLENT SYNOPTIC AGREEMENT WITH A RAPIDLY DEEPENING LOW
OVER THE WESTERN ATLANTIC OCEAN/GULF-STREAM DURING SATURDAY. WHAT
CONTINUES TO DIFFER...AND ITS WELL SEEN IN THE ENSEMBLE DATA...IS
THE EVENTUAL TRACK OF THIS DEEPENING CYCLONE/NOR-EASTER. THE ECMWF
IS THE FURTHER WEST WITH ITS TRACK...FOLLOWED BY THE GGEM THEN THE
RECENTLY UPGRADED GFS. THE TROWAL/DEFORMATION AXIS WILL BE CLOSE TO
OUR SOUTHERN COUNTIES /EASTERN ULSTER-DUTCHESS-LITCHFIELD-SOUTHERN
BERKSHIRE/ WHERE WE WILL INCREASE POPS INTO LIKELY THRESHOLDS AND
FOLLOW A BLENDED APPROACH. THIS WOULD SUGGEST POSSIBLE HEADLINES
FOR THESE AREAS AS WELL WITH ALL THERMAL PROFILES AT THIS TIME
SUGGESTING AN ALL SNOW EVENT. FURTHER NORTH AND WEST...AS THE UPPER
TROUGH DIGS AND CAPTURES THIS SOUTHERN STREAM SYSTEM...THERE COULD
BE A PERIOD OF EITHER LIGHT SNOW OR SNOW SHOWERS WITH NOT MUCH QPF.
SPEAKING OF QPF...UTILIZING A BLENDED APPROACH FROM THE ABOVE
MENTIONED MODELS...VALUES RANGE FROM NEAR ONE TENTH OF AN INCH FOR
THE ALBANY AREA...TO 1 INCH ACROSS SOUTHERN DUTCHESS AND LITCHFIELD
COUNTIES. SO A RATHER SHARP GRADIENT IS EXPECTED. AS WITH MID
LEVEL WINDS...WITH A EASTERLY COMPONENT IN THE WIND DIRECTION AND A
GRADUAL INCREASE IN MAGNITUDES...SOME DOWNSLOPING OFF THE
BERKS/TACONICS MAY CUT DOWN FURTHER QPF INTO THE MID-UPR HUDSON
RIVER VALLEY. PER COLLABORATION...WE WILL HIGHLIGHT THE POTENTIAL
INTO THE HWO AT THIS TIME AND MONITOR TRENDS VERY CLOSELY.
TIME FRAME OF POTENTIAL IMPACT WOULD BE FROM AROUND THE NOON HOUR ON
SATURDAY THROUGH SATURDAY EVENING.
WINDS WILL BE ON INCREASE SATURDAY NIGHT AS THE STORM DEEPENS AND
EVENTUALLY FILLS TO THE EAST OF THE GULF OF MAINE. WHERE SNOW DOES
FALL MAY RESULT IN ADDITIONAL BLOWING AND DRIFTING. WIND CHILLS AT
THIS TIME SHOULD REMAIN ABOVE ADVISORY LEVEL CRITERIA.
SUNDAY INTO MONDAY...ANOTHER RATHER STRONG PV ANOMALY DIVES
SOUTHEAST WITHIN THE LONG WAVE TROUGH AS A CLIPPER TRACKS ALONG THE
I70-I80 CORRIDORS. GLOBAL MODELS DIFFER SIGNIFICANTLY WITH THE
TRACK OF THIS LOW PRESSURE AREA AS THE GFS ATTEMPTS TO SHOW A
NEGATIVE TILT DEVELOPING OVER THE NORTHEAST WITH THE ECMWF MORE
PROGRESSIVE AND OPEN WAVE ALOFT. FOR NOW...WE WILL PLACE SLIGHT
CHANCE TO CHANCE POPS SOUTH OF I90. THERMAL COLUMN REMAINS ALL COLD
FOR MAINLY SNOW.
TUESDAY...INCREASE CONSENSUS OF A RIDGE OF HIGH PRESSURE FOR A
TRANQUIL PERIOD OF WEATHER AND NEAR SEASONABLE TEMPERATURES.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS INTO THE EVENING HOURS...THEN AS THE CLIPPER TYPE
SYSTEM APPROACHES...VFR CIGS BECOME MVFR FROM KALB SOUTHWARD ALONG
WITH A PERIOD OF LIGHT SNOW MAINLY IMPACTING KPOU. FOR THIS...WE
WILL PLACE A TEMPO GROUP FROM 04Z-08Z. OTHERWISE...MAINLY A MVFR CIG
ISSUE OVERNIGHT FOR KALB-KPSF-KPOU. SOME OF THESE LOWER CLOUDS MAY
MAKE IT INTO KGFL TOWARD DAWN.
DURING THURSDAY...LATEST TRENDS ARE FAVORING MORE LOWER CLOUDS ON
THE CUSP OF MVFR/VFR BUT REMAINING DRY.
THE WINDS WILL REMAIN LIGHT AT LESS THAN 5 KNOTS OR BE
CALM.
OUTLOOK...
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SN.
SATURDAY NIGHT: SLIGHT CHANCE OF SHSN.
SUNDAY TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT FIVE
DAYS.
A CLIPPER LOW PASSING SOUTH OF THE REGION MAY BRING SOME LIGHT SNOW
TO AREAS SOUTH OF THE CAPITAL REGION. OTHERWISE...COLD AND DRY
WEATHER WILL PERSIST THROUGH FRIDAY NIGHT.
A DEVELOPING NOR`EASTER COULD BRING MODERATE TO SIGNIFICANT SNOWFALL
MAINLY SOUTH AND EAST OF ALBANY ON SATURDAY.
ICE WILL CONTINUE TO THICKEN ON RIVERS...STREAMS...CREEKS...LAKES
AND OTHER BODIES OF WATER OVER THE NEXT SEVERAL DAYS.
THE EAGLE BRIDGE GAGE ON THE HOOSIC RIVER CONTINUES TO BE HAMPERED
BY ICE EFFECTS AND RECENTLY HAS EXHIBITED A DECREASE IN GAGE
LEVELS /BELOW FLOOD STAGE/.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...JPV
NEAR TERM...BGM/JPV
SHORT TERM...JPV
LONG TERM...BGM
AVIATION...IAA/BGM
HYDROLOGY...HWJIV/JPV
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
905 AM EST TUE JAN 20 2015
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS MUCH OF THE CONUS TO THE
EAST OF THE CONTINENTAL DIVIDE WITHIN A VERY BROAD LONGWAVE TROUGH.
EMBEDDED WITHIN THIS BROAD FLOW ARE SEVERAL WEAK SHORTWAVE
IMPULSES...HOWEVER AT THIS TIME NONE OF THESE ARE PRODUCING MUCH IN
THE WAY OF HAZARDOUS WEATHER...AND THE PATTERN ACROSS THE CONUS IS
UNUSUALLY QUIET FOR MID/LATE JANUARY. ONE OF THESE WEAK SHORTWAVE
IMPULSES IS CURRENTLY CROSSING THE EASTERN GULF OF MEXICO AND WILL
PASS OVER THE FLORIDA PENINSULA THIS AFTERNOON AND THEN OFF INTO THE
ATLANTIC THIS EVENING.
MORNING SATELLITE IMAGERY SHOWS A LARGE SWATH OF MAINLY MID/HIGH
LEVEL CLOUDS ASSOCIATED WITH THIS SHORTWAVE AND ASSOCIATED JET
STRUCTURE OVERHEAD. EXPECT SKIES TO REMAIN MOSTLY CLOUDY TO CLOUDY
FOR THE REMAINDER OF THE MORNING HOURS...WITH THE CHANCES FOR A FEW
SUNNY BREAKS INCREASING THE DEEPER INTO THE AFTERNOON WE GO. THE
BEST CHANCE AT ANY SIGNIFICANT SUN LATER TODAY WILL BE TO THE NORTH
OF THE TAMPA BAY AREA ACROSS THE NATURE COAST ZONES.
AREAS OF MAINLY LIGHT RAINFALL CAN BE SEEN ON REGIONAL RADARS OVER
THE COASTAL WATERS TO THE SOUTH OF TAMPA BAY. THIS RAINFALL IS THE
RESULT OF A COMBINATION BETWEEN LARGE SCALE QG FORCING ASSOCIATED
WITH THE SHORTWAVE...BROAD LOW LEVEL ISENTROPIC UPGLIDE IN THE LOWER
LEVELS ALONG THE 295-305K SURFACES...AND BROAD UPPER LEVEL
DIVERGENCE WITHIN THE LER OF A 90-100KT UPPER JET STREAK DROPPING
DOWN THE BACKSIDE OF THE SHORTWAVE.
THE RADAR IMAGE SEEMS TO SHOW LIGHT RAINFALL ALREADY SPREADING
ACROSS THE SOUTHERN HALF OF THE FLORIDA PENINSULA...HOWEVER THIS IS
SIMPLY DUE TO THE HIGHER ELEVATION SCANNING OF THE RADARS OVER THESE
AREAS. THE 20/12Z KTBW SOUNDING PROFILE SHOWS A VERY DRY ATMOSPHERIC
COLUMN IN PLACE BELOW 600-500MB...SO ANY PRECIP FALLING OUT OF THE
CLOUD DECK OVER LAND IS CURRENTLY VIRGA. OVER TIME...TIME-HEIGHT
ANALYSIS DOES SHOW THE COLUMN MOISTENING SOMEWHAT...AND DO EXPECT
AREAS SOUTH OF THE I-4 CORRIDOR TO SEE SOME SHOWER ACTIVITY DEVELOP
INTO THE LATER MORNING AND AFTERNOON HOURS. HOWEVER...THE OVERALL
FORCING FOR LIFT...INCLUDING THE UPGLIDE IS SHOWN TO WEAKEN WITH
TIME...AND THEREFORE DO NOT ANTICIPATE MUCH MORE THAN SOME PERIODS
OF LIGHT RAIN (LOW ACCUMULATION) SOUTH OF THE TAMPA BAY REGION...A
FEW SPRINKLES THROUGH TAMPA BAY (LITTLE TO NO ACCUMULATION)...AND
ESSENTIALLY NO RAIN ACROSS THE NATURE COAST TODAY.
TEMPERATURES ARE LOOKING TO REMAIN COOL TODAY...ESPECIALLY FROM I-4
SOUTHWARD WHERE A LONGER DURATION OF CLOUDS...AND SOME ADDED
WET-BULBING/EVAPORATIVE COOLING SLOWS THE DIURNAL TEMP CLIMB. WILL
LIKELY BE LOWERING HIGH TEMPS FOR THE CENTRAL/SOUTHERN ZONES BY A
COUPLE OF DEGREES WITH THE MORNING FORECAST UPDATE.
WHAT LITTLE FORCING FOR LIFT ASSOCIATED WITH SHORTWAVE QUICKLY
PASSES EAST OF THE REGION THIS EVENING. A SECONDARY SHORTWAVE WILL
QUICKLY BE ON ITS HEELS APPROACHING FROM THE SLOWER MS
VALLEY...HOWEVER THIS ENERGY AND ITS SYNOPTIC SUPPORT FOR LIFT LOOK
TO PASS MAINLY NORTH OF OUR REGION OVERNIGHT. THEREFORE...SOME SCT
LIGHT SHOWERS EARLY EVENING SOUTH WILL END BEFORE MIDNIGHT...WITH A
GENERALLY DRY OVERNIGHT FOR ALL THEREAFTER. TEMPERATURES WILL BE
SEASONABLE WITH MID/UPPER 40S NORTH OF THE I-4 CORRIDOR AND 50S
ELSEWHERE.
A QUIET SENSIBLE WEATHER DAY ON TAP FOR WEDNESDAY AS THE UPPER
LEVELS RETURN TO ZONAL FLOW AND WEAK HIGH PRESSURE AT THE SURFACE
RIDGES IN OVER THE REGION FROM THE NORTHWEST. EXPECT MUCH MORE IN
THE WAY OF SUNSHINE FOR WEDNESDAY WITH HIGH TEMPERATURES GENERALLY
IN THE LOWER 70S NORTH AND MIDDLE 70S SOUTH. HAVE A GREAT TUESDAY
EVERYBODY!
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE REGION UNDER WIDESPREAD MID/HIGH
LEVEL CLOUDS. THESE CONDITIONS WITH DEVELOPING MAINLY LIGHT SHOWERS
OR SPRINKLES EXPECTED THROUGH THE REMAINDER OF THE DAYLIGHT HOURS.
BEST CHANCES FOR SHOWERS AND A BRIEF PERIOD OF OF MVFR CIGS WILL
EXIST TO THE SOUTH OF THE TAMPA BAY REGION. SHOWERS END THIS EVENING
WITH VFR CONDITIONS LIKELY THROUGH MUCH OF THE OVERNIGHT. SOME
PATCHY GROUND FOG IS LIKELY LATE AT NIGHT...WITH KLAL AND KPGD
SEEING THE BEST SHOT AT A PERIOD OF VIS RESTRICTIONS IN THE HOURS
APPROACHING DAWN. ANY EARLY MORNING FOG BURNS OFF QUICKLY ON
WEDNESDAY WITH PREVAILING VFR CONDITIONS EXPECTED THE REMAINDER OF
THE DAY.
&&
.MARINE...
PATCHY LIGHT RAIN OR SPRINKLES WILL AFFECT THE WATERS MAINLY SOUTH
OF TAMPA BAY AS A WEAK DISTURBANCE OVER THE GULF WILL QUICKLY PASS
BY THE STATE TODAY. GENERALLY BENIGN WEATHER FOR THE NEXT COUPLE OF
DAYS...WITH WINDS 15 KNOTS OR LESS AND SEAS 2 FEET OR LESS EXPECTED
THROUGH THURSDAY. AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE GULF
AT THE END OF THE WEEK...BRINGING INCREASED RAIN CHANCES FRIDAY
THROUGH SATURDAY AS WELL AS INCREASING WINDS AND SEAS. NO HAZARDS
EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 69 58 73 59 / 10 10 10 0
FMY 72 60 77 61 / 40 20 10 0
GIF 70 56 75 58 / 10 10 10 0
SRQ 69 57 74 58 / 20 10 0 0
BKV 70 50 72 52 / 0 10 10 0
SPG 68 60 72 62 / 10 10 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...DOUGHERTY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
305 PM CST TUE JAN 20 2015
.SHORT TERM...
339 AM CST
THROUGH TODAY...
MAIN FORECAST CHALLENGES/CONCERNS TODAY ARE WITH A BRIEF WINDOW OF
FREEZING RAIN OR FREEZING DRIZZLE THIS MORNING ACROSS NORTHERN
ILLINOIS...AND THEN INCREASING CLOUD COVER AND CHANCES FOR PRECIP
VERY LATE THIS AFTERNOON.
BEEN MONITORING AN AREA OF PRECIP WHICH HAS MOVED SOUTHEAST
THROUGH IOWA AND SOUTHWEST WISCONSIN THIS MORNING...APPROACHING
THE RFD AREA AT THIS TIME. MAIN AREA OF PRECIP ACROSS THE REGION
HAS REMAINED WELL NORTH OF THE CWA ACROSS WISCONSIN AS SURFACE LOW
HAS DROPPED SOUTHEAST INTO NORTHWEST ILLINOIS THIS MORNING...BUT
STRONG VORT MAX HAS ENABLED FOR THE CONTINUED PRECIP DEVELOPMENT
FURTHER TO THE SOUTHWEST. THIS WILL LIKELY CONTINUE OVER THE NEXT
SEVERAL HOURS...MOVING INTO NORTH CENTRAL ILLINOIS OVER THE NEXT
1-2 HOURS AND THEN INTO NORTHEAST ILLINOIS AROUND THE 13Z TIME
FRAME. FORECAST SOUNDINGS INDICATING A MARGINAL SETUP FOR SNOW
DEVELOPMENT WITH RAIN THE LIKELY PRECIP TYPE. UPSTREAM OBS HAVE
SUPPORTED THIS WITH BOTH RAIN AND SNOW BEING REPORTED ACROSS IOWA
AND WISCONSIN. ONCE AGAIN...DONT ANTICIPATE THIS TO CHANGE ACROSS
THE CWA AND WITH AIR TEMPS AROUND FREEZING...AM A LITTLE CONCERNED
FOR A BRIEF WINDOW OF FREEZING RAIN OR FREEZING DRIZZLE AS THIS
PUSHES THROUGH. THIS WILL LIKELY BE LIGHT AND VERY BRIEF...UNDER
ONE HOUR...BUT STILL COULD CAUSE ISSUES THIS MORNING. THIS WILL
ESPECIALLY BE THE CASE ACROSS NORTHWEST AND NORTH CENTRAL ILLINOIS
WHERE TEMPS HAVE BEEN COOLER. ANY FREEZING COMPONENT WILL LIKELY
BECOME LESS OF A PROBLEM AS IT APPROACHES NORTHEAST ILLINOIS WITH
TEMPS SLIGHTLY WARMER. HAVE ISSUED AN SPS THIS MORNING AND WILL
CONTINUE TO MONITOR THE SOUTHEASTWARD MOVEMENT AND TEMP TRENDS FOR
AREAS ACROSS NORTHEAST ILLINOIS.
SKIES WILL LIKELY BE PARTLY CLOUDY TO PARTLY SUNNY TO START OFF
THIS MORNING AS CLOUD COVER OVER EAST CENTRAL ILLINOIS AND
NORTHWEST INDIANA DEPART...AND THEN AS LOW STRATUS DROPS SOUTH OUT
OF WISCONSIN. THIS SOUTHWARD MOVING STRATUS WILL BRING A RETURN TO
MOSTLY CLOUDY SKIES BY THE AFTERNOON FOR ALL AREAS...WITH ABOVE
NORMAL TEMPS STILL APPEARING LIKELY. DID LOWER TEMPS FOR TODAY
MAINLY OVER NORTHERN ILLINOIS WHERE STRATUS WILL APPROACH
QUICKER...BUT LEFT TEMPS OVER THE SOUTHERN HALF ALONE WHERE HIGHS
COULD REACH AROUND 40. HAVE POPS INCREASING VERY LATE IN THE
AFTERNOON TODAY MAINLY FOR THE NORTHERN HALF OF THE CWA BUT THEY
MAY BE TOO QUICK AS THE ARRIVAL OF THE NEXT SYSTEM AND PRECIP NOT
LIKELY UNTIL LATER THIS EVENING.
RODRIGUEZ
&&
.LONG TERM...
339 AM CST
TONIGHT THROUGH MONDAY...
A NICELY DEFINED MID-LEVEL CIRCULATION ON WATER VAPOR IMAGERY THIS
MORNING OVER NORTH DAKOTA WILL RIDE AN UPPER LEVEL PV INTRUSION
INTO THE FORECAST AREA LATE TONIGHT. IN ADVANCE OF THIS LOW
AMPLITUDE WAVE...SUBTLE ISENTROPIC ASCENT SHOULD GRADUALLY
INCREASE ALONG THE 900-700MB THERMAL BOUNDARY ATOP THE AREA. WITH
LOW-LEVEL SATURATION ALREADY IN PLACE BY THAT TIME...LIGHT
PRECIPITATION SHOULD EXPAND IN COVERAGE THIS EVENING...MAINLY
NORTH OF I-80. GIVEN THE FORCING IS LIGHT AT FIRST AND LIMITED ICE
CRYSTAL INITIATION PER FORECAST SOUNDINGS...A PERIOD OF LIGHT
LIQUID COULD OCCUR AT FIRST. SURFACE TEMPERATURES LOOK TO BE AT
OR POSSIBLY A BIT ABOVE FREEZING...SO NOT TOO CONCERNED ABOUT
THAT IF IT OCCURS EARLY THIS EVENING. FORCING INCREASES LATE IN
THE EVENING AND ESPECIALLY OVERNIGHT SO THAT CONFIDENCE INCREASES
PRECIPITATION TYPE WOULD CHANGE TO SNOW.
IT TAKES A WHILE FOR THIS SYSTEM TO MOVE THROUGH THE AREA WITH THE
VORT MAX STILL FORECAST OVER NORTHWEST INDIANA AT MIDDAY WEDNESDAY.
THIS INDICATES A LIGHT SNOW EVENT OF LONGER DURATION...AGAIN
ESPECIALLY FOR AREAS NORTH OF I-80. WHILE THERE WILL LIKELY BE
BREAKS IN THE SNOW DUE TO THE OVERALL MARGINAL
FORCING...ACCUMULATIONS OF AROUND ONE TO ONE AND A HALF INCHES
REMAIN FORECAST TO MATERIALIZE FROM THIS EVENING THROUGH MIDDAY
WEDNESDAY WITH SHARPLY LESSER AMOUNTS SOUTH OF I-80. RATES SHOULD
MAINLY BE LIGHT WITH LIMITED MESOSCALE FORCING...THOUGH AS THE
SNOW GROWTH ZONE LOWERS BY DAYBREAK WEDNESDAY SOME FORCING COULD
BETTER EXIST IN THE SNOW GROWTH AREA TO HELP INCREASE EFFICIENCY.
WILL NOT ISSUE ANY SPS AT THIS TIME WITH IT STILL BEING 24 HOURS
OUT AND TO AVOID CONFUSION WITH CURRENT SPS OUT FOR THIS MORNINGS
LIGHT FREEZING PRECIPITATION. PLUS IT WILL GIVE THE DAY CHANCE A
BETTER OPPORTUNITY TO REFINE DETAILS.
SOME LIGHT SNOW OR FLURRIES WILL REMAIN POSSIBLE WEDNESDAY AFTERNOON
AND EVENING ACROSS THE ENTIRE AREA WITH THE WAVE SHEARING AS IT
MOVES THROUGH. TEMPERATURES ARE NOT FORECAST TO RISE MUCH
WEDNESDAY GIVEN AMPLE CLOUDINESS.
COLDER AND MORE SEASONAL AIR DOES FILTER IN BEHIND THIS SYSTEM FOR
WEDNESDAY NIGHT INTO THURSDAY. LIMITED HEIGHT RISES AND SUPPRESSION
POINT TOWARD LOW CLOUDS HANGING AROUND...POSSIBLY EVEN THROUGH
THURSDAY NIGHT. SO HAVE LOW TEMPERATURES WEDNESDAY NIGHT STILL
ONLY FORECAST IN THE MID 20S.
AS THE PATTERN BEGINS TO AMPLIFY OVER THE NORTH AMERICAN WEST COAST
INTO CANADA...A STRONG LOW WILL MOVE NORTH OF THE GREAT LAKES AND
SWING A COLD FRONT INTO OUR REGION FRIDAY NIGHT. AHEAD OF THIS
SYSTEM...FRIDAY LOOKS LIKE A BREEZY DAY WITHIN A MODEST WARM SECTOR.
WITH SOME LIGHT SNOW COVER ACROSS THE NORTHERN FORECAST
AREA...SIMILAR TO THIS PAST SATURDAY...TEMPERATURES AGAIN MAY
HANG BELOW 40 BUT EXPECTING AT LEAST TO BE CLOSE AND TOPPING 40
SOUTH. THE FROPA LOOKS TO BE DRY WITH VERY LIMITED MOISTURE
FORECAST.
AS SIGNIFICANT UPPER HEIGHT ANOMALIES DEVELOP OVER THE WEST COAST
AND A ROBUST 150+ KT NORTHERN PACIFIC JET OVERTOPS THIS...THE
PATTERN CONTINUES TO SUPPORT A COLD PUNCH OR TWO LATE IN THE
WEEKEND INTO NEXT WEEK. THE REGION WOULD CERTAINLY LOOK TO HAVE A
CHANCE FOR SNOW AS THIS PATTERN TRANSITION OCCURS...AND RIGHT NOW
DETERMINISTIC MODELS AND ENSEMBLES HINT AT SUNDAY WITH A DIGGING
NORTHERN STREAM SYSTEM. HAVE GONE WITH A SMART BLEND OF MODEL
POPS AT THIS TIME.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* VARIABLE VISIBILITY WITH FG/BR IN THE REGION AND SNOW
OVERSPREADING THIS EVENING/TONIGHT.
* NORTHEAST WINDS AOA 10KT MID TO LATE THIS AFTERNOON.
* IFR/LIFR CIGS.
BMD
//DISCUSSION...UPDATED 18Z...
SURFACE LOW LIES OVER FAR NE IL AND NW IN THIS AFTERNOON WITH
TROUGHING EXTENDING NORTHWEST ACROSS NORTHWEST ILLINOIS. WINDS
WITHIN THE FRONTAL TROUGH ARE LIGHT AND FOG IS REDUCING VSBY TO LESS
THAN A MILE AT TIMES...BUT AS THE TROUGH SAGS SOUTH THROUGH THE
EVENING...EXPECT NORTH/NORTHEAST WINDS TO PICKUP SLIGHTLY BEHIND THE
DEPARTING LOW. NORTHEAST WINDS IN EXCESS OF 10 KTS ARE POSSIBLE
STARTING MID AFTERNOON AT ORD. PRIMARILY IFR CIGS ARE EXPECTED TO
PERSIST THROUGH THE REMAINDER OF THE TAF PERIOD LOWERING TO LIFR
THIS EVENING/TONIGHT AS AN UPPER LEVEL DISTURBANCE DIGS ACROSS THE
MIDWEST WITH SNOW OVERSPREADING THE REGION. PRECIPITATION IS
EXPECTED TO INITIALLY START AS DRIZZLE OR A DRIZZLE/SNOW MIX BEFORE
CHANGING TO ALL SNOW MID TO LATE THIS EVENING. LIGHT SNOW WILL
CONTINUE OVERNIGHT THROUGH MIDDAY WEDNESDAY WITH AN INCH OR TWO
ACCUMULATION POSSIBLE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* LOW-MEDIUM CONFIDENCE IN VSBY TRENDS.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...LOW-MEDIUM IN SPEEDS
MAINLY THIS AFTERNOON.
* MEDIUM CONFIDENCE IN PRECIP TYPE/TIMING.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...SLIGHT CHANCE OF LIGHT SNOW.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF LIGHT SNOW.
MONDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.MARINE...
304 PM CST
FOR HEADLINES...GALES ARE IN THE FORECAST FOR THE NORTH HALF OF THE
LAKE THURSDAY NIGHT INTO FRIDAY MORNING...BUT IT IS STILL TOO FAR
OUT TO PUT ANY HEADLINES OUT YET. FOR THE NEARSHORE WATERS...A
SMALL CRAFT ADVISORY MAY BE NEEDED FOR THE IL WATERS FRIDAY...MAYBE
INTO FRIDAY EVENING. IT STILL LOOKS LIKE A MARGINAL EVENT SO WILL
HOLD OFF WITH ANY HEADLINES.
A WEAK LOW IS OVER SOUTHEAST INDIANA AND ANOTHER WEAK LOW WILL MOVE
OVER NORTHERN IL TOMORROW MORNING. NORTHEAST WINDS WILL DIMINISH TO
5 TO 10 KT OVERNIGHT OVER THE NORTH HALF WHILE THE SOUTH HALF WILL
SEE NORTHEAST WINDS DIMINISH TO 10 TO 15 KT OVERNIGHT. WINDS BECOME
NORTH BEHIND THE LOW TOMORROW AFTERNOON. WINDS CONTINUE TO BACK TO
WEST THURSDAY AS HIGH PRESSURE SPREADS OVER THE REGION. THE
GRADIENT TIGHTENS OVER THE NORTHERN HALF OF THE LAKE AS THE HIGH
SHIFTS SOUTH AND A LARGE LOW MOVES OVER ONTARIO LATE THURSDAY NIGHT
INTO FRIDAY MORNING. SOUTHWEST WINDS INCREASE TO LOW END GALES OVER
THE NORTH HALF THURSDAY NIGHT...WITH SOUTHWEST WINDS TO 30 KT ACROSS
THE ENTIRE LAKE FRIDAY AFTERNOON. THE LOWS COLD FRONT SWINGS OVER
THE LAKE FRIDAY NIGHT WITH WINDS BECOMING WEST 15 TO 20 KT. WINDS
THEN SHIFT TO NORTHWEST SATURDAY. HIGH PRESSURE QUICKLY PASSES OVER
THE LAKE SATURDAY NIGHT AND ANOTHER LOW IS EXPECTED TO MOVE OVER
ILLINOIS SUNDAY. GUIDANCE CONTINUES TO DIFFER ON THE TIMING AND
EXACT LOCATION OF THIS LOW...BUT BOTH LONG TERM GUIDANCE MEMBERS
HAVE THE LOW PASSING SOUTH OF THE LAKE.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
253 PM CST Tue Jan 20 2015
.SHORT TERM...(Tonight)
ISSUED AT 245 PM CST TUE JAN 20 2015
Lingering sunshine is rapidly fading across the CWA, as the low
cloud deck has advanced as far southeast as Decatur and Paris, while
mid and high clouds spread east from Missouri. The lower clouds have
stopped the temperature rise in the north with mid/upper 30s this
afternoon, while mid 40s to around 50 degrees were observed further
south where the sunshine had lingered the longest.
Main forecast concern for tonight is with the clipper system dropping
southeast from South Dakota this afternoon. Morning model suite is
in good agreement with a low track roughly along a Moline to Kankakee
line after midnight. With this type of system, the highest snow
chances are generally along/north of the track, and the forecast
soundings across our northern CWA show little in the way of snow-
generating ice crystals in the -10 to -20C layer. However, the
soundings are moist enough below 750 mb that some light snow should
be a possibility with just enough lift passing through, mainly after
midnight. Snow threat should mainly be from about Macomb to Bloomington
northward, although some light snow may make it as far southeast as
Champaign and Danville toward sunrise.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 245 PM CST TUE JAN 20 2015
Several low amplitude shortwaves to affect the forecast area this
period bringing low chance POPs to the region along with temperatures
continuing to average above normal. The wave that brings our northern
areas a little snow tonight into Wednesday will be shifting to our
east during the afternoon hours. The weak surface low associated with
the shortwave is still forecast to pass to our north, roughly along
the I-80 corridor with the better threat for light accumulating snows
along and north of the track of the low. As the low passes to our
east later in the day, there may be enough cyclonic flow/weak cold
air advection for some scattered flurries across the north into Wed.
night.
There is a lull in the parade of shortwaves tracking from northwest
to southeast into our area until late Saturday night or Sunday when
a stronger wave is forecast to arrive in our area. This wave is
forecast to dig sharply southeast into the mean longwave trof position
with a surface wave then expected to shift across parts of Illinois
during the day Sunday. Once again, the model consistency with this
feature continues to be poor at best. The latest ECMWF now tracks
the low further northeast than the GFS, which would translate to more
of a rain/snow mixture, while the 12z GFS operation model solution
would lean more towards a period of light snow during the day. The
latest GFS ensemble mean takes the storm system across north central
Illinois with the 12z UK and GEM models also trending further north
and east. At this point, not very confident the models have a decent
enough handle on the wave for Sunday, so no significant changes will
be made to the timing of the precip into our area along with precip
types on Sunday. Will keep the chances for snow or rain in the morning
across the forecast area, and then mainly rain during the afternoon
based on the further northeast track to the surface wave which helps
edge temperatures up close to 40 degrees Sunday afternoon.
Will continue with low chance POPs for light snow Sunday night as
the system shifts off to our southeast with flurries possible on
Monday due to low level cold advection/cyclonic flow in the wake
of the storm system. The next upper level wave will be fast
approaching from the northwest on Tuesday, but once again, the
main surface low will track well to our north keeping us on the
mild side for late January with not much in the way of rain or
snow to deal with.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1132 AM CST TUE JAN 20 2015
Area of IFR ceilings dropping southeast this afternoon, and should
be reaching the KSPI-KCMI corridor by 19Z. Ceilings 800-1200 feet
expected through the afternoon. Latest HRRR indicates some
scouring of the low clouds taking place west to east this evening,
but have only indicated this for KSPI for now, as the areas
further east/north will be coming under the influence of a fast
moving clipper system now in South Dakota. Have maintained the
VCSH from KPIA-KCMI for now, but forecast soundings would suggest
more of a drizzle/snow grains profile as the better ice crystal
generation remains in northern Illinois. Northwest winds to trend
southwest this evening ahead of the clipper, before going back
toward the west tomorrow morning following its passage. Have
maintained some high IFR/low MVFR conditions after the passage as
well.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Smith
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1002 AM CST TUE JAN 20 2015
.SHORT TERM...
339 AM CST
THROUGH TODAY...
MAIN FORECAST CHALLENGES/CONCERNS TODAY ARE WITH A BRIEF WINDOW OF
FREEZING RAIN OR FREEZING DRIZZLE THIS MORNING ACROSS NORTHERN
ILLINOIS...AND THEN INCREASING CLOUD COVER AND CHANCES FOR PRECIP
VERY LATE THIS AFTERNOON.
BEEN MONITORING AN AREA OF PRECIP WHICH HAS MOVED SOUTHEAST
THROUGH IOWA AND SOUTHWEST WISCONSIN THIS MORNING...APPROACHING
THE RFD AREA AT THIS TIME. MAIN AREA OF PRECIP ACROSS THE REGION
HAS REMAINED WELL NORTH OF THE CWA ACROSS WISCONSIN AS SURFACE LOW
HAS DROPPED SOUTHEAST INTO NORTHWEST ILLINOIS THIS MORNING...BUT
STRONG VORT MAX HAS ENABLED FOR THE CONTINUED PRECIP DEVELOPMENT
FURTHER TO THE SOUTHWEST. THIS WILL LIKELY CONTINUE OVER THE NEXT
SEVERAL HOURS...MOVING INTO NORTH CENTRAL ILLINOIS OVER THE NEXT
1-2 HOURS AND THEN INTO NORTHEAST ILLINOIS AROUND THE 13Z TIME
FRAME. FORECAST SOUNDINGS INDICATING A MARGINAL SETUP FOR SNOW
DEVELOPMENT WITH RAIN THE LIKELY PRECIP TYPE. UPSTREAM OBS HAVE
SUPPORTED THIS WITH BOTH RAIN AND SNOW BEING REPORTED ACROSS IOWA
AND WISCONSIN. ONCE AGAIN...DONT ANTICIPATE THIS TO CHANGE ACROSS
THE CWA AND WITH AIR TEMPS AROUND FREEZING...AM A LITTLE CONCERNED
FOR A BRIEF WINDOW OF FREEZING RAIN OR FREEZING DRIZZLE AS THIS
PUSHES THROUGH. THIS WILL LIKELY BE LIGHT AND VERY BRIEF...UNDER
ONE HOUR...BUT STILL COULD CAUSE ISSUES THIS MORNING. THIS WILL
ESPECIALLY BE THE CASE ACROSS NORTHWEST AND NORTH CENTRAL ILLINOIS
WHERE TEMPS HAVE BEEN COOLER. ANY FREEZING COMPONENT WILL LIKELY
BECOME LESS OF A PROBLEM AS IT APPROACHES NORTHEAST ILLINOIS WITH
TEMPS SLIGHTLY WARMER. HAVE ISSUED AN SPS THIS MORNING AND WILL
CONTINUE TO MONITOR THE SOUTHEASTWARD MOVEMENT AND TEMP TRENDS FOR
AREAS ACROSS NORTHEAST ILLINOIS.
SKIES WILL LIKELY BE PARTLY CLOUDY TO PARTLY SUNNY TO START OFF
THIS MORNING AS CLOUD COVER OVER EAST CENTRAL ILLINOIS AND
NORTHWEST INDIANA DEPART...AND THEN AS LOW STRATUS DROPS SOUTH OUT
OF WISCONSIN. THIS SOUTHWARD MOVING STRATUS WILL BRING A RETURN TO
MOSTLY CLOUDY SKIES BY THE AFTERNOON FOR ALL AREAS...WITH ABOVE
NORMAL TEMPS STILL APPEARING LIKELY. DID LOWER TEMPS FOR TODAY
MAINLY OVER NORTHERN ILLINOIS WHERE STRATUS WILL APPROACH
QUICKER...BUT LEFT TEMPS OVER THE SOUTHERN HALF ALONE WHERE HIGHS
COULD REACH AROUND 40. HAVE POPS INCREASING VERY LATE IN THE
AFTERNOON TODAY MAINLY FOR THE NORTHERN HALF OF THE CWA BUT THEY
MAY BE TOO QUICK AS THE ARRIVAL OF THE NEXT SYSTEM AND PRECIP NOT
LIKELY UNTIL LATER THIS EVENING.
RODRIGUEZ
&&
.LONG TERM...
339 AM CST
TONIGHT THROUGH MONDAY...
A NICELY DEFINED MID-LEVEL CIRCULATION ON WATER VAPOR IMAGERY THIS
MORNING OVER NORTH DAKOTA WILL RIDE AN UPPER LEVEL PV INTRUSION
INTO THE FORECAST AREA LATE TONIGHT. IN ADVANCE OF THIS LOW
AMPLITUDE WAVE...SUBTLE ISENTROPIC ASCENT SHOULD GRADUALLY
INCREASE ALONG THE 900-700MB THERMAL BOUNDARY ATOP THE AREA. WITH
LOW-LEVEL SATURATION ALREADY IN PLACE BY THAT TIME...LIGHT
PRECIPITATION SHOULD EXPAND IN COVERAGE THIS EVENING...MAINLY
NORTH OF I-80. GIVEN THE FORCING IS LIGHT AT FIRST AND LIMITED ICE
CRYSTAL INITIATION PER FORECAST SOUNDINGS...A PERIOD OF LIGHT
LIQUID COULD OCCUR AT FIRST. SURFACE TEMPERATURES LOOK TO BE AT
OR POSSIBLY A BIT ABOVE FREEZING...SO NOT TOO CONCERNED ABOUT
THAT IF IT OCCURS EARLY THIS EVENING. FORCING INCREASES LATE IN
THE EVENING AND ESPECIALLY OVERNIGHT SO THAT CONFIDENCE INCREASES
PRECIPITATION TYPE WOULD CHANGE TO SNOW.
IT TAKES A WHILE FOR THIS SYSTEM TO MOVE THROUGH THE AREA WITH THE
VORT MAX STILL FORECAST OVER NORTHWEST INDIANA AT MIDDAY WEDNESDAY.
THIS INDICATES A LIGHT SNOW EVENT OF LONGER DURATION...AGAIN
ESPECIALLY FOR AREAS NORTH OF I-80. WHILE THERE WILL LIKELY BE
BREAKS IN THE SNOW DUE TO THE OVERALL MARGINAL
FORCING...ACCUMULATIONS OF AROUND ONE TO ONE AND A HALF INCHES
REMAIN FORECAST TO MATERIALIZE FROM THIS EVENING THROUGH MIDDAY
WEDNESDAY WITH SHARPLY LESSER AMOUNTS SOUTH OF I-80. RATES SHOULD
MAINLY BE LIGHT WITH LIMITED MESOSCALE FORCING...THOUGH AS THE
SNOW GROWTH ZONE LOWERS BY DAYBREAK WEDNESDAY SOME FORCING COULD
BETTER EXIST IN THE SNOW GROWTH AREA TO HELP INCREASE EFFICIENCY.
WILL NOT ISSUE ANY SPS AT THIS TIME WITH IT STILL BEING 24 HOURS
OUT AND TO AVOID CONFUSION WITH CURRENT SPS OUT FOR THIS MORNINGS
LIGHT FREEZING PRECIPITATION. PLUS IT WILL GIVE THE DAY CHANCE A
BETTER OPPORTUNITY TO REFINE DETAILS.
SOME LIGHT SNOW OR FLURRIES WILL REMAIN POSSIBLE WEDNESDAY AFTERNOON
AND EVENING ACROSS THE ENTIRE AREA WITH THE WAVE SHEARING AS IT
MOVES THROUGH. TEMPERATURES ARE NOT FORECAST TO RISE MUCH
WEDNESDAY GIVEN AMPLE CLOUDINESS.
COLDER AND MORE SEASONAL AIR DOES FILTER IN BEHIND THIS SYSTEM FOR
WEDNESDAY NIGHT INTO THURSDAY. LIMITED HEIGHT RISES AND SUPPRESSION
POINT TOWARD LOW CLOUDS HANGING AROUND...POSSIBLY EVEN THROUGH
THURSDAY NIGHT. SO HAVE LOW TEMPERATURES WEDNESDAY NIGHT STILL
ONLY FORECAST IN THE MID 20S.
AS THE PATTERN BEGINS TO AMPLIFY OVER THE NORTH AMERICAN WEST COAST
INTO CANADA...A STRONG LOW WILL MOVE NORTH OF THE GREAT LAKES AND
SWING A COLD FRONT INTO OUR REGION FRIDAY NIGHT. AHEAD OF THIS
SYSTEM...FRIDAY LOOKS LIKE A BREEZY DAY WITHIN A MODEST WARM SECTOR.
WITH SOME LIGHT SNOW COVER ACROSS THE NORTHERN FORECAST
AREA...SIMILAR TO THIS PAST SATURDAY...TEMPERATURES AGAIN MAY
HANG BELOW 40 BUT EXPECTING AT LEAST TO BE CLOSE AND TOPPING 40
SOUTH. THE FROPA LOOKS TO BE DRY WITH VERY LIMITED MOISTURE
FORECAST.
AS SIGNIFICANT UPPER HEIGHT ANOMALIES DEVELOP OVER THE WEST COAST
AND A ROBUST 150+ KT NORTHERN PACIFIC JET OVERTOPS THIS...THE
PATTERN CONTINUES TO SUPPORT A COLD PUNCH OR TWO LATE IN THE
WEEKEND INTO NEXT WEEK. THE REGION WOULD CERTAINLY LOOK TO HAVE A
CHANCE FOR SNOW AS THIS PATTERN TRANSITION OCCURS...AND RIGHT NOW
DETERMINISTIC MODELS AND ENSEMBLES HINT AT SUNDAY WITH A DIGGING
NORTHERN STREAM SYSTEM. HAVE GONE WITH A SMART BLEND OF MODEL
POPS AT THIS TIME.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* IFR/LIFR TODAY AND TONIGHT.
* REDUCED VIS IN LIGHT SNOW LATER TONIGHT INTO WEDNESDAY.
* NORTHEAST WINDS APPROACHING 10KT LATER THIS AFTERNOON.
RODRIGUEZ/BMD
//DISCUSSION...UPDATED 12Z...
QUICK AND SMALL AREA OF A WINTRY MIX OF FREEZING RAIN/SNOW/PELLETS
STILL PUSHING EAST THROUGH NORTHERN ILLINOIS AT THIS TIME. TIMING
AND DURATION STILL APPEAR TO BE ON TRACK WITH THIS REALLY NOT LONG
LASTING EARLY THIS MORNING...WITH THE OVERALL SIZE ACTUALLY
SHRINKING WITH TIME. THIS WILL QUICKLY PASS WITH THEN MVFR AND IFR
CEILINGS TO QUICKLY PUSH ACROSS THE TERMINALS THROUGH MID MORNING.
IT DOES LOOK LIKE THE WINDOW BETWEEN THIS TRANSITION WILL BE SMALL
AS ROCKFORD HAS ALREADY TRANSITIONED FROM VFR TO IFR IN A MATTER OF
ONE TO TWO HOURS. CONTINUED THAT TREND WITH THE REMAINING
TERMINALS...WITH IFR TO THEN PREVAIL FOR THE REMAINDER OF THE DAY.
APPROACHING SYSTEM TONIGHT WILL LIKELY HELP TO LOWER CEILINGS
FURTHER AS A PERIOD OF LIGHT SNOW WILL BE OBSERVED INTO WEDNESDAY
MORNING. CONFIDENCE WITH EXACT START TIME IS LOWER AT THIS TIME AS
CONDITIONS INITIALLY DONT APPEAR TO BE FAVORABLE FOR SNOW
DEVELOPMENT THIS EVENING. NONETHELESS...SNOW WILL BECOME MORE
PREVAILING WITH TIME TONIGHT. SNOW WILL THEN TAPER OFF DURING THE
MORNING HOURS...BUT WITH CEILINGS LIKELY HOLDING ONTO IFR DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM HIGH CONFIDENCE WITH CIG TRENDS.
* HIGH CONFIDENCE WITH LIGHT SNOW TONIGHT INTO WEDNESDAY...MEDIUM
CONFIDENCE WITH TIMING.
* LOW CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...SLIGHT CHANCE OF LIGHT SNOW.
THURSDAY...VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...CHANCE OF LIGHT SNOW.
MONDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.MARINE...
200 AM CST
A COUPLE OF WEAK LOW PRESSURE SYSTEMS WILL TRACK JUST SOUTH OF LAKE
MICHIGAN THROUGH WEDNESDAY...WITH ONE THIS MORNING AND THE OTHER
WEDNESDAY AFTERNOON. WITH HIGH PRESSURE TO THE NORTHEAST THIS
PATTERN WILL BRING NORTHEASTERLY WINDS ACROSS MOST OF THE
LAKE...THOUGH THE GRADIENT IS MODEST AT BEST. THE HIGHEST WINDS
TODAY AND TONIGHT...WITH GUSTS AROUND 20 KT...LOOK TO BE JUST
NORTH OF THE LOW TRACK. THESE EAST-NORTHEAST WINDS SHOULD BE
POINTED INTO THE ILLINOIS NEARSHORE...ESPECIALLY NORTH OF
CHICAGO...BUT CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA.
HIGH PRESSURE WILL MAKE A QUICK PASS OVER THE LAKE LATE WEDNESDAY
NIGHT AND THURSDAY MORNING BEFORE GIVING WAY TO STRONG SOUTHWEST
WINDS. THE PATTERN THURSDAY NIGHT INTO FRIDAY FORECAST BY COMPUTER
MODELS WITH A LOW PRESSURE OF SUB 29.50 INCHES PASSING EASTWARD
ACROSS ONTARIO LOOKS LIKE ONE SUPPORTIVE OF GALES. SO WILL CARRY
SOME 35 KT GUSTS NAMELY ACROSS THE NORTH AND CENTRAL DURING LATE
THURSDAY NIGHT AND FRIDAY. THE FORECAST WINDS COULD END UP
NEEDING TO BE STRONGER IN TIME. THE COLD FRONT WITH THIS SYSTEM
WILL BEGIN USHERING IN A PATTERN MORE SEASONAL FOR LATE JANUARY
WITH COLDER AIR AND SUCCESSIVE SYSTEMS INTO EARLY NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
944 AM CST Tue Jan 20 2015
.UPDATE...
ISSUED AT 940 AM CST TUE JAN 20 2015
Main forecast issue for the rest of today is with cloud cover.
Large area of stratocumulus dropping southeast out of the upper
Mississippi Valley, with the leading edge currently roughly along
a Galesburg to Joliet line, although a finger of lower clouds is
extending as far southeast as Peoria. Latest RAP 925-850 mb layer
humidity plot suggests this should spread over a large part of
central Illinois into early afternoon. Have updated the sky trends
in the zones and grids for this trend. Made some minor
adjustments to the hourly temperature/dew point grids as well, but
no significant changes to the high temperatures were made.
&&
.SHORT TERM...(Today)
ISSUED AT 323 AM CST TUE JAN 20 2015
A fairly potent short-wave trough evident on 08z/2am water vapor
imagery over northeast Iowa brought clouds and a few light rain
showers to the northern half of the KILX CWA earlier this evening.
Latest radar imagery shows a few lingering showers east of the I-55
corridor, while skies have already cleared further west across the
Illinois River Valley. Based on satellite timing tools, all of
central and southeast Illinois will be mostly clear by 12z. As the
wave skirts across northern Illinois and Indiana later today,
additional cloud cover behind this feature along a trailing vort max
will begin to sink southeastward toward the area. Meanwhile,
high/thin clouds associated with a separate system over the Plains
will spill eastward as well. End result will be a sunny start to
the day, with increasing clouds as the day progresses. Most
locations will be partly sunny by mid to late afternoon, with mostly
cloudy conditions noted along/northwest of the Illinois River. It
will be another unseasonably warm day, with high temperatures
climbing about 10 degrees normal for this time of year. Afternoon
readings will range from around 40 degrees northwest of the Illinois
River where clouds will become thickest, to the lower 50s southeast
of I-70.
&&
.LONG TERM...(Tonight through Monday)
ISSUED AT 323 AM CST TUE JAN 20 2015
Extended forecast continues to look relatively tranquil for mid to
late January, with a series of weak disturbances expected to pass
through the region. System number one has been well advertised for
several days and is still on target for tonight into Wednesday.
Trends have consistently been further north with its track and
associated QPF and the latest model run is no exception. Given this
well-established trend and good agreement among the various models,
have trimmed PoPs to focus chances mainly along/north of I-74. Any
precip that occurs will be quite light, with heavier amounts
expected to remain further north along/north of the I-80 corridor.
With temps initially in the 40s this afternoon, precip may begin as
a rain/snow mix toward midnight around Galesburg, then will
transition to light snow overnight into Wednesday morning. High
temps on Wednesday will climb into the upper 30s and lower 40s, so
snow will transition back to rain or a rain/snow mix by midday.
Little or no snow accumulation is expected across the north.
Once the wave passes to the east of the region, mild and dry weather
is expected Thursday through Saturday, with high temperatures in the
upper 30s/lower 40s gradually climbing back into the lower to middle
40s by Saturday. The next system of interest will arrive by Sunday:
however, model agreement and consistency remains poor. The main
question will be how deep the system becomes as it dives
southeastward out of Canada and carves out a long-wave trough across
the eastern CONUS. GFS is quite aggressive with the amplification
of the wave, indicating a closed 500mb low developing over southern
Iowa/northern Missouri by 00z Mon. This particular solution would
result in a colder atmospheric profile and a slower exit of the
system, which could lead to snow accumulation Sunday night into
Monday. Meanwhile, the ECMWF/GEM/UKMET all feature
open/progressive waves that quickly pass through the region on
Sunday. The latest ECMWF has trended slightly deeper with the
system, but still not as amplified as the GFS. An examination of
the Ensemble GFS and its members reveals the operational GFS is
actually an outlier. As a result, am favoring a faster-moving/weaker
wave late in the weekend. This will likely bring a period of light
precip to the area Sunday into Monday morning. With no source of
cold air to tap into, temps will once again be marginal for snow,
with highs on Sunday reaching the upper 30s and lower 40s. Have
gone with rain or a rain/snow mix during the day accordingly,
changing to light snow Sunday night. A minor accumulation will be
possible before the precip exits Monday morning.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 522 AM CST TUE JAN 20 2015
Skies have cleared across central IL this morning following a
system that passed through last night. Observations are currently
showing mostly VFR visibilities, although patchy MVFR visibility
in fog is present. For a few hours this morning, have included
VCFG in TAFs nearby where rain fell last night, with tempo MVFR BR
at KPIA and KCMI which have had lower visibilities reported this
morning. Meanwhile, region of IFR/MVFR ceilings associated with a
system over northern Plains/Upper Mississippi Valley region will
move into central Illinois through the day. Decreasing ceilings
into MVFR category in TAFs during the afternoon due to this
system, and bringing VCSH and local IFR into KPIA, KBMI, KCMI late
evening due to a chance for light snow showers.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS GOODLAND KS
139 PM MST TUE JAN 20 2015
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 139 PM MST TUE JAN 20 2015
EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS NW
FLOW IN PLACE FROM THE CANADIAN ROCKIES AND INTO THE SOUTHERN
PLAINS. SHORTWAVE TROUGH AXIS FROM LAST NIGH HAS SHIFTED
EAST..WITH UPSTREAM THERE IS ANOTHER WEAK SHORTWAVE IN THE
NORTHERN STREAM OVER ALBERTA CANADA. IN THE SOUTHERN STREAM A
STRONGER SHORTWAVE TROUGH IS MOVING ONSHORE OVER SOUTHERN
CALIFORNIA.
THIS AFTERNOON...LOW TO MID CLOUD SHIELD ASSOCIATED WITH DECAYED
PRECIPITATION BAND HAS SHIFTED SOUTH. 950-850 MB THETA E LAPSE
RATES INDICATE SHALLOW UNSTABLE LAYER THAT HAS LED A FEW POCKETS
OF SPRINKLES DEVELOPING OVER EASTERN WYOMING/NORTHEAST
COLORADO...WHICH IS CURRENTLY TRANSITIONING SOUTH AND EAST. THIS
WILL BE TIED TO DAYTIME HEATING AND I DO NOT ANTICIPATE ANY
MEASURABLE PRECIP WITH THIS ACTIVITY.
TONIGHT-WEDNESDAY...NORTHERN AND SOUTHERN STREAM SHORTWAVE TROUGHS
WILL MERGE AND DEEPEN LATE TONIGHT WITH NOSE OF H3 JET SLIDING
OVER EASTERN COLORADO/NORTHWEST KANSAS. AS THIS UPPER LOW DEEPENS
BETTER FORCING WILL MAINLY BE OVER EASTERN COLORADO...LIKELY
SOUTHWEST OF OUR CWA. DESPITE THIS...THERE SHOULD BE ENOUGH
FORCING FOR LIGHT SNOW DEVELOPMENT ACROSS THE SOUTHWEST PORTIONS
OF OUR CWA...WITH BEST CHANCES IN THE 12Z-20Z TIME FRAME. I COULD
SEE AROUND ONE INCH OF SNOW ACCUMULATIONS OVER WESTERN PARTS OF
KIT CARSON AND CHEYENNE COUNTIES IN COLORADO...WITH LESS THAN ONE
INCH FURTHER EAST. ALTHOUGH THERE IS AN OVERLAPPING PRECIP SIGNAL
FURTHER NORTHEAST INTO NORTHWEST KANSAS...TRACK OF MAIN UPPER LOW
AND POSITION OF UPPER LEVEL DIVERGENCE LOWERS CONFIDENCE IN LIGHT
SNOW OVER NW KANSAS. I TAPERED POPS TO THE NORTHEAST IN LINE WITH
CONSENSUS...WITH AND HAVE ACTIVITY WINDING DOWN DURING THE
AFTERNOON AS UPPER LEVEL FORCING SHIFTS SOUTH.
TEMP FORECAST WED MAY BE ON THE COLDER SIDE AS H85 TEMPS AROUND -4C
RANGE ARE ADVERTISED BY MOST GUIDANCE. WITH CLOUD COVER/PRECIP IN
THE WEST THROUGH THE EARLY AFTERNOON WE MAY NOT SEE MUCH WARMING
AT ALL...AND TEMPS HOVERING AROUND OR BELOW FREEZING. IN THE EAST
WE MAY SEE SOME BREAKS IN CLOUD COVER BY THE AFTERNOON...WHICH
COULD ALLOW TEMPS TO RECOVER INTO THE LOW 40S. NOT AN EASY TEMP
FORECAST AS POSITION OF PRECIP/CLOUD COVER WILL DETERMINE CUTOFF
IN SUB FREEZING HIGHS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 1239 PM MST TUE JAN 20 2015
PRECIPITATION SHOULD END BY 00Z THURSDAY AS SHORTWAVE TROUGH
CONTINUES TO MOVE SOUTH. SHORTWAVE RIDGING WILL FOLLOW ON THURSDAY
WITH DRY CONDITIONS AND TEMPERATURES NEAR NORMAL. NORTHWEST FLOW
WILL RETURN ON FRIDAY AND CONTINUE THROUGH THE WEEKEND WITH A
COUPLE OF EMBEDDED WEAK DISTURBANCES. ONE MOVES THROUGH ON FRIDAY
BUT WILL LACK ADEQUATE LOW LEVEL MOISTURE FOR MORE THAN A FEW
AFTERNOON SPRINKLES AS TEMPERATURES WARM TO THE LOWER 50S. ANOTHER
STRONGER SYSTEM WILL MOVE THROUGH THE NORTHERN PLAINS AND UPPER
MISSISSIPPI RIVER VALLEY SATURDAY NIGHT AND SUNDAY. THE UPPER
DYNAMICS WILL BE TOO FAR AWAY FOR PRECIPITATION CHANCES...THOUGH
IT WILL CREATE A TIGHT HEIGHT AND PRESSURE GRADIENT FOR WINDY
CONDITIONS ON SUNDAY ESPECIALLY IN EASTERN SECTIONS OF THE LOCAL
AREA LIKE MCCOOK AND HILL CITY. AN UPPER RIDGE WILL BUILD WEST
ACROSS THE ROCKIES AND ADJACENT PLAINS EARLY NEXT WEEK RESULTING
IN DRY CONDITIONS AND MUCH ABOVE NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1030 AM MST TUE JAN 20 2015
PATCHY DENSE FOG HAS DEVELOPED OVER PARTS OF EASTERN COLORADO
IMMEDIATELY BEHIND LIGHT RAIN/SNOW THAT HAS TRANSITIONED WELL
SOUTH OF INTERSTATE 70. SHORT RANGE GUIDANCE INDICATES THIS FOG
SHOULD REMAIN WEST OF KGLD. WITH CLEARING SKIES AND WARMING
TEMPERATURES THIS FOG SHOULD QUICKLY BURN OFF...SO I DECIDED TO
LEAVE MENTION OUT OF THE TAF FOR FOR NOW. AT BOTH KGLD AND KMCK
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD...THOUGH
WITH LIGHT SNOW POSSIBLY DEVELOPING LATE IN THE TAF PERIOD IN
EASTERN COLORADO THERE IS A CHANCE CONDITIONS COULD DROP AT KGLD
TO MVFR OR LOWER. NOT A LOT OF CONFIDENCE AS THE TRACK OF THE
UPPER LEVEL DISTURBANCE SHOULD FAVOR LOCATIONS SOUTH OF
INTERSTATE 70.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
536 PM EST TUE JAN 20 2015
.UPDATE...
ISSUED AT 535 PM EST TUE JAN 20 2015
LATEST STLT IMAGERY INDICATES LK INDUCED VORTEX E OF THE KEWEENAW IS
TENDING TO TURN MORE TO THE NNE AND AWAY FM THE KEWEENAW PENINSULA.
THIS MOTION IS IN LINE WITH THE LLVL SSW FLOW THIS MESOVORTEX IS
ENCOUNTERING ON THE NRN FLANK OF SFC RDG AXIS ORIENTED E-W ACROSS
UPR MI. OPTED TO LOWER POPS OVER THE KEWEENAW FOR THIS EVNG BASED ON
THIS CHANGE IN TRACK.
CONSIDERING THE DRYNESS OF THE AIRMASS IN PLACE...WITH PWAT IN THE
0.10 TO 0.15 RANGE...OPTED TO LOWER FCST MIN TEMPS OVER THE ERN CWA
WHERE SKIES ARE LIKELY TO REMAIN MOCLR AND WINDS LGT THRU THE NGT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EST TUE JAN 20 2015
WATER VAPOR LOOP AND RUC ANALYSIS INDICATES A NW FLOW OVER THE
REGION AS THE MAIN SHORTWAVE EMBEDDED IN THIS FLOW IS WELL SW OF THE
UPPER LAKES. VIS SATELLITE LOOP SHOWS LOW CLOUDS PERSISTING OVER THE
W-SW FCST AREA WITH MOSTLY SUNNY SKIES ACROSS THE NCNTRL AND ERN
FCST AREA. MESOSCALE LOW IS EVIDENT JUST EAST OF THE KEWEENAW AND
MOVING SLOWLY EAST.
TONIGHT...LATEST HIGH RES MODELS HAVING A POOR TIME RESOLVING
MESOSCALE FEATURE EAST OF THE KEWEENAW THIS EVENING. AS A
RESULT...HAD TO ADJUST POPS UP TO 50-60 PCT OVER THE TIP OF
THE KEWEENAW AT LEAST THROUGH THIS EVENING TO ACCOUNT FOR THE LES
POTENTIAL. ALSO BUMPED UP SNOW ACCUMULATION TO 1-2 INCHES OVER
THE TIP OF THE KEWEENAW THROUGH THIS EVENING BUT THIS MAY BE TOO
CONSERVATIVE GIVEN FAIRLY IMPRESSIVE LOOK TO THE MESOLOW ON VISIBLE
SATELLITE.
ELSEWHERE TONIGHT TEMPS AND CLOUDS WILL BE THE MAIN CONCERN AND
DETERMINING HOW FAR WEST THE CLEARING LINE REACHES INTO SW UPPER MI
THIS EVENING. THIS WILL HAVE A BIG IMPACT ON MIN TEMPS. AT A
MININUM...WHERE THERE IS CLEARING...SHOULD SEE TEMPS LOWERING INTO
AT LEAST THE SINGLE DIGITS BLO ZERO AND PROBABLY WILL REACH COLDER
THAN -10F AT SOME OF THE COLDER EASTERN INTERIOR LOCATIONS. WILL
KEEP TEMPS CLOSER TO 10-12F OVER THE FAR WEST WHERE CLOUDS SHOULD
PERSIST THROUGH THE NIGHT.
WEDNESDAY...WEAK SHORTWAVE MOVING DOWN FROM MANITOBA/NRN ONTARIO
WILL PUSH A SURFACE TROUGH INTO NW UPPER MI/SCNTRL LAKE SUPERIOR.
LOOK FOR THIS TROUGH TO BECOME THE FOCUS FOR SOME LIGHT LES AS 850
MB TEMPS LINGER AROUND -11C. WILL MAINTAIN SLIGHT CHC TO LOW CHC
POPS OVER NW AND NCNTRL ZONES. EXPECT TEMPS TO REBOUND FM CHILLY
OVERNIGHT LOWS AND REACH INTO THE LOWER 20S EAST TO MID TO UPPER 20S
WEST AND CENTRAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 435 PM EST TUE JAN 20 2015
A TROUGH OF LOW PRESSURE WILL REMAIN ACROSS EASTERN CANADA AND MUCH
OF THE EASTERN U.S. THROUGH THE PERIOD...WITH A RIDGE ACROSS THE FAR
W. AS A RESULT...A SERIES OF WAVES WILL DIVE S ACROSS THE UPPER
GREAT LAKES REGION. HIGH TEMPERATURES WILL GENERALLY HOVER IN THE
20S TO LOW 30S...WHICH IS NEAR TO JUST SLIGHTLY ABOVE NORMAL FOR MID
TO LATE JANUARY.
TO BEGIN 00Z THURSDAY NW FLOW OVER THE W HALF AND 850MB TEMPS NEAR -
12C...WITH SOME MOISTURE IN THE DGZ WILL BE OPPOSED TO THE
STRENGTHENING INVERSION. EXPECT ONLY LIGHT SNOW. UPPER MI WILL BE IN
BETWEEN A WAVE SLIDING TO OUR S...AND AN ADDITIONAL WAVE STRETCHING
FROM THE 500MB TROUGH AND ASSOCIATED SFC LOW OVER HUDSON BAY
STRETCHING ACROSS ONTARIO. WHILE COOLER AIR WILL BRIEFLY SLIDE IN
WEDNESDAY NIGHT...MOISTURE WILL BE LIMITED AS HIGH PRESSURE SLOWLY
BUILDS IN.
STRENGTHENING WINDS WILL BE THE MAIN STORY FOR THURSDAY NIGHT INTO
FRIDAY...AS UPPER MI RESIDES BETWEEN THE STRONG LOW SETTLING ACROSS
THE OHIO VALLEY AND A ORGANIZED LOW ACROSS N MANITOBA AT 00Z FRIDAY.
EXPECT THE LOW TO SHIFT TO CROSS N AND CENTRAL ONTARIO FRIDAY...AND
EXIT ACROSS JAMES BAY FRIDAY EVENING. HIGHS IN THE LOW TO MID 30S
/AROUND 10F ABOVE NORMAL/ LOOK REASONABLE FOR FRIDAY AFTERNOON AS
850MB TEMPS RISE TO 0 TO 3C...ALONG WITH A CHANCE OF SNOW AND PATCHY
BLOWING SNOW ALONG LAKE SUPERIOR. THE MAIN SFC TROUGH WILL USHER
COOLER AIR BACK INTO THE CWA SATURDAY...WITH SLOWLY FALLING TEMPS
THROUGH THE DAY. DECREASED WINDS SLIGHTLY FROM WHAT WE HAD
ORIGINALLY FRIDAY NIGHT/SATURDAY...WHICH WILL NEED TO BE MONITORED.
THURSDAY NIGHT/FRIDAY MORNING STILL LOOKS TO BE THE PERIOD OF
STRONGEST WINDS. THE 20/12Z ECMWF HAS COME IN WITH 40-50KT W WINDS
AT 850MB 06-12Z FRIDAY.
LOOKING FARTHER OUT...THERE ARE SOME SIGNIFICANT DISCREPANCIES AS WE
MOVE INTO THE LONGER RANGE OF THIS FCST...FROM MONDAY AFTERNOON ON.
ONE CHANGE FOR THIS ISSUANCE WAS TO LIMIT THE TIME OF N-NE WINDS
ACROSS LAKE SUPERIOR...BRINING LIGHT TO MODERATE LES INTO N CENTRAL
UPPER MI. THE 02/12Z ECMWF STILL HOLDS ONTO THE EXTENDED DURATION OF
COOL N-NE WINDS...WITH 850MB TEMPS AROUND -15C. THE GFS SWEEPS A LOW
ACROSS THE AREA...WITH VARIED WIND DIRECTIONS. WILL CONTINUE A BLEND
AT THIS TIME...AND WAIT FOR FCST MODELS TO HAVE A BETTER HANDLE ON
THIS LATER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE JAN 20 2015
EXPECT PREDOMINANT MVFR CONDITIONS THROUGH TAF PERIOD AT MOST OF THE
SITES AS LOW-LVL MOISTURE REMAINS TRAPPED UNDER PERSISTENT
SUBSIDENCE INVERSION. DRIER EASTERLY WIND AT KSAW COULD ALLOW FOR LOW
CLOUDS TO SCATTER OUT THROUGH THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE JAN 20 2015
A RELATIVELY TRANQUIL PERIOD IS EXPECTED INTO THURSDAY WITH WINDS
BELOW 30 KNOTS. HOWEVER...SW WINDS WILL INCREASE TO 30 KNOTS THU
NIGHT WITH A FEW GALE FORCE GUSTS POSSIBLE AS LOW PRESSURE MOVES
TOWARD JAMES BAY. WEST WINDS TO 30 KNOTS ARE EXPECTED TO CONTINUE
FRI INTO SAT AS WINDS VEER TO THE WEST AND THEN TO THE NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
436 PM EST TUE JAN 20 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EST TUE JAN 20 2015
WATER VAPOR LOOP AND RUC ANALYSIS INDICATES A NW FLOW OVER THE
REGION AS THE MAIN SHORTWAVE EMBEDDED IN THIS FLOW IS WELL SW OF THE
UPPER LAKES. VIS SATELLITE LOOP SHOWS LOW CLOUDS PERSISTING OVER THE
W-SW FCST AREA WITH MOSTLY SUNNY SKIES ACROSS THE NCNTRL AND ERN
FCST AREA. MESOSCALE LOW IS EVIDENT JUST EAST OF THE KEWEENAW AND
MOVING SLOWLY EAST.
TONIGHT...LATEST HIGH RES MODELS HAVING A POOR TIME RESOLVING
MESOSCALE FEATURE EAST OF THE KEWEENAW THIS EVENING. AS A
RESULT...HAD TO ADJUST POPS UP TO 50-60 PCT OVER THE TIP OF
THE KEWEENAW AT LEAST THROUGH THIS EVENING TO ACCOUNT FOR THE LES
POTENTIAL. ALSO BUMPED UP SNOW ACCUMULATION TO 1-2 INCHES OVER
THE TIP OF THE KEWEENAW THROUGH THIS EVENING BUT THIS MAY BE TOO
CONSERVATIVE GIVEN FAIRLY IMPRESSIVE LOOK TO THE MESOLOW ON VISIBLE
SATELLITE.
ELSEWHERE TONIGHT TEMPS AND CLOUDS WILL BE THE MAIN CONCERN AND
DETERMINING HOW FAR WEST THE CLEARING LINE REACHES INTO SW UPPER MI
THIS EVENING. THIS WILL HAVE A BIG IMPACT ON MIN TEMPS. AT A
MININUM...WHERE THERE IS CLEARING...SHOULD SEE TEMPS LOWERING INTO
AT LEAST THE SINGLE DIGITS BLO ZERO AND PROBABLY WILL REACH COLDER
THAN -10F AT SOME OF THE COLDER EASTERN INTERIOR LOCATIONS. WILL
KEEP TEMPS CLOSER TO 10-12F OVER THE FAR WEST WHERE CLOUDS SHOULD
PERSIST THROUGH THE NIGHT.
WEDNESDAY...WEAK SHORTWAVE MOVING DOWN FROM MANITOBA/NRN ONTARIO
WILL PUSH A SURFACE TROUGH INTO NW UPPER MI/SCNTRL LAKE SUPERIOR.
LOOK FOR THIS TROUGH TO BECOME THE FOCUS FOR SOME LIGHT LES AS 850
MB TEMPS LINGER AROUND -11C. WILL MAINTAIN SLIGHT CHC TO LOW CHC
POPS OVER NW AND NCNTRL ZONES. EXPECT TEMPS TO REBOUND FM CHILLY
OVERNIGHT LOWS AND REACH INTO THE LOWER 20S EAST TO MID TO UPPER 20S
WEST AND CENTRAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 435 PM EST TUE JAN 20 2015
A TROUGH OF LOW PRESSURE WILL REMAIN ACROSS EASTERN CANADA AND MUCH
OF THE EASTERN U.S. THROUGH THE PERIOD...WITH A RIDGE ACROSS THE FAR
W. AS A RESULT...A SERIES OF WAVES WILL DIVE S ACROSS THE UPPER
GREAT LAKES REGION. HIGH TEMPERATURES WILL GENERALLY HOVER IN THE
20S TO LOW 30S...WHICH IS NEAR TO JUST SLIGHTLY ABOVE NORMAL FOR MID
TO LATE JANUARY.
TO BEGIN 00Z THURSDAY NW FLOW OVER THE W HALF AND 850MB TEMPS NEAR -
12C...WITH SOME MOISTURE IN THE DGZ WILL BE OPPOSED TO THE
STRENGTHENING INVERSION. EXPECT ONLY LIGHT SNOW. UPPER MI WILL BE IN
BETWEEN A WAVE SLIDING TO OUR S...AND AN ADDITIONAL WAVE STRETCHING
FROM THE 500MB TROUGH AND ASSOCIATED SFC LOW OVER HUDSON BAY
STRETCHING ACROSS ONTARIO. WHILE COOLER AIR WILL BRIEFLY SLIDE IN
WEDNESDAY NIGHT...MOISTURE WILL BE LIMITED AS HIGH PRESSURE SLOWLY
BUILDS IN.
STRENGTHENING WINDS WILL BE THE MAIN STORY FOR THURSDAY NIGHT INTO
FRIDAY...AS UPPER MI RESIDES BETWEEN THE STRONG LOW SETTLING ACROSS
THE OHIO VALLEY AND A ORGANIZED LOW ACROSS N MANITOBA AT 00Z FRIDAY.
EXPECT THE LOW TO SHIFT TO CROSS N AND CENTRAL ONTARIO FRIDAY...AND
EXIT ACROSS JAMES BAY FRIDAY EVENING. HIGHS IN THE LOW TO MID 30S
/AROUND 10F ABOVE NORMAL/ LOOK REASONABLE FOR FRIDAY AFTERNOON AS
850MB TEMPS RISE TO 0 TO 3C...ALONG WITH A CHANCE OF SNOW AND PATCHY
BLOWING SNOW ALONG LAKE SUPERIOR. THE MAIN SFC TROUGH WILL USHER
COOLER AIR BACK INTO THE CWA SATURDAY...WITH SLOWLY FALLING TEMPS
THROUGH THE DAY. DECREASED WINDS SLIGHTLY FROM WHAT WE HAD
ORIGINALLY FRIDAY NIGHT/SATURDAY...WHICH WILL NEED TO BE MONITORED.
THURSDAY NIGHT/FRIDAY MORNING STILL LOOKS TO BE THE PERIOD OF
STRONGEST WINDS. THE 20/12Z ECMWF HAS COME IN WITH 40-50KT W WINDS
AT 850MB 06-12Z FRIDAY.
LOOKING FARTHER OUT...THERE ARE SOME SIGNIFICANT DISCREPANCIES AS WE
MOVE INTO THE LONGER RANGE OF THIS FCST...FROM MONDAY AFTERNOON ON.
ONE CHANGE FOR THIS ISSUANCE WAS TO LIMIT THE TIME OF N-NE WINDS
ACROSS LAKE SUPERIOR...BRINING LIGHT TO MODERATE LES INTO N CENTRAL
UPPER MI. THE 02/12Z ECMWF STILL HOLDS ONTO THE EXTENDED DURATION OF
COOL N-NE WINDS...WITH 850MB TEMPS AROUND -15C. THE GFS SWEEPS A LOW
ACROSS THE AREA...WITH VARIED WIND DIRECTIONS. WILL CONTINUE A BLEND
AT THIS TIME...AND WAIT FOR FCST MODELS TO HAVE A BETTER HANDLE ON
THIS LATER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE JAN 20 2015
EXPECT PREDOMINANT MVFR CONDITIONS THROUGH TAF PERIOD AT MOST OF THE
SITES AS LOW-LVL MOISTURE REMAINS TRAPPED UNDER PERSISTENT
SUBSIDENCE INVERSION. DRIER EASTERLY WIND AT KSAW COULD ALLOW FOR LOW
CLOUDS TO SCATTER OUT THROUGH THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE JAN 20 2015
A RELATIVELY TRANQUIL PERIOD IS EXPECTED INTO THURSDAY WITH WINDS
BELOW 30 KNOTS. HOWEVER...SW WINDS WILL INCREASE TO 30 KNOTS THU
NIGHT WITH A FEW GALE FORCE GUSTS POSSIBLE AS LOW PRESSURE MOVES
TOWARD JAMES BAY. WEST WINDS TO 30 KNOTS ARE EXPECTED TO CONTINUE
FRI INTO SAT AS WINDS VEER TO THE WEST AND THEN TO THE NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 PM EST TUE JAN 20 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EST TUE JAN 20 2015
WATER VAPOR LOOP AND RUC ANALYSIS INDICATES A NW FLOW OVER THE
REGION AS THE MAIN SHORTWAVE EMBEDDED IN THIS FLOW IS WELL SW OF THE
UPPER LAKES. VIS SATELLITE LOOP SHOWS LOW CLOUDS PERSISTING OVER THE
W-SW FCST AREA WITH MOSTLY SUNNY SKIES ACROSS THE NCNTRL AND ERN
FCST AREA. MESOSCALE LOW IS EVIDENT JUST EAST OF THE KEWEENAW AND
MOVING SLOWLY EAST.
TONIGHT...LATEST HIGH RES MODELS HAVING A POOR TIME RESOLVING
MESOSCALE FEATURE EAST OF THE KEWEENAW THIS EVENING. AS A
RESULT...HAD TO ADJUST POPS UP TO 50-60 PCT OVER THE TIP OF
THE KEWEENAW AT LEAST THROUGH THIS EVENING TO ACCOUNT FOR THE LES
POTENTIAL. ALSO BUMPED UP SNOW ACCUMULATION TO 1-2 INCHES OVER
THE TIP OF THE KEWEENAW THROUGH THIS EVENING BUT THIS MAY BE TOO
CONSERVATIVE GIVEN FAIRLY IMPRESSIVE LOOK TO THE MESOLOW ON VISIBLE
SATELLITE.
ELSEWHERE TONIGHT TEMPS AND CLOUDS WILL BE THE MAIN CONCERN AND
DETERMINING HOW FAR WEST THE CLEARING LINE REACHES INTO SW UPPER MI
THIS EVENING. THIS WILL HAVE A BIG IMPACT ON MIN TEMPS. AT A
MININUM...WHERE THERE IS CLEARING...SHOULD SEE TEMPS LOWERING INTO
AT LEAST THE SINGLE DIGITS BLO ZERO AND PROBABLY WILL REACH COLDER
THAN -10F AT SOME OF THE COLDER EASTERN INTERIOR LOCATIONS. WILL
KEEP TEMPS CLOSER TO 10-12F OVER THE FAR WEST WHERE CLOUDS SHOULD
PERSIST THROUGH THE NIGHT.
WEDNESDAY...WEAK SHORTWAVE MOVING DOWN FROM MANITOBA/NRN ONTARIO
WILL PUSH A SURFACE TROUGH INTO NW UPPER MI/SCNTRL LAKE SUPERIOR.
LOOK FOR THIS TROUGH TO BECOME THE FOCUS FOR SOME LIGHT LES AS 850
MB TEMPS LINGER AROUND -11C. WILL MAINTAIN SLIGHT CHC TO LOW CHC
POPS OVER NW AND NCNTRL ZONES. EXPECT TEMPS TO REBOUND FM CHILLY
OVERNIGHT LOWS AND REACH INTO THE LOWER 20S EAST TO MID TO UPPER 20S
WEST AND CENTRAL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 AM EST TUE JAN 20 2015
A BUILDING RIDGE OVER THE PACIFIC NORTHWEST AND WESTERN CANADA
TODAY WILL LEAD TO NORTHWESTERLY FLOW ALOFT AND SEND A SERIES OF
SHORTWAVES/CLIPPERS SOUTHEAST ACROSS THE GREAT LAKES AND EASTERN
CANADA. ALTHOUGH THESE CLIPPERS WILL BE BRINGING CANADIAN AIR ACROSS
THE REGION...THE COLDEST AIR WILL REMAIN LOCKED OVER HUDSON BAY.
THUS...EXPECT TEMPERATURES TO BE NEAR OR ABOVE NORMAL OVER THE
NEXT WEEK WITH OCCASIONAL PERIODS OF LIGHT SNOW OR FLURRIES WITH THE
CLIPPERS. BETWEEN THE CLIPPERS THERE MAY BE A FEW PERIODS OF VERY
LIGHT LAKE EFFECT SNOW...BUT 925/850MB TEMPS ARE FAIRLY MARGINAL AND
THE WIND FIELDS ARE CONSTANTLY FLUCTUATING TO SUPPORT MUCH MORE THAN
OCCASIONAL SHOWERS. ALL IN ALL...NOT MUCH IN THE WAY OF SIGNIFICANT
WEATHER FOR THE PERIOD.
THE AREA WILL BE BETWEEN SHORTWAVES ON WEDNESDAY (ONE WILL BE
TRACKING THROUGH SOUTHERN WISCONSIN AND ILLINOIS AND THE OTHER
THROUGH NORTHERN ONTARIO)...WHICH WILL LIMIT ANY LARGER SCALE
SUPPORT FOR PRECIPITATION. BUT A LOW LEVEL THERMAL TROUGH WILL
GRADUALLY DROP SOUTHEAST ACROSS THE CWA LATE TONIGHT THROUGH
WEDNESDAY NIGHT...LEADING TO WINDS GRADUALLY BECOMING NORTHWEST ON
WEDNESDAY BEFORE QUICKLY BACKING SOUTHWESTERLY THURSDAY AHEAD OF A
SLIGHTLY STRONGER SHORTWAVE AND CLIPPER THAT WILL MOVE THROUGH
NORTHERN ONTARIO ON FRIDAY. MODELS ARE STILL VARYING ON THE AMOUNT
OF COLD AIR...BUT THERE SHOULD BE ENOUGH TO PRODUCE SOME LIGHT
SNOW...ESPECIALLY OVER THE WEST AND KEWEENAW WHERE LIGHT
NORTHWESTERLY WINDS ARE EXPECTED. FARTHER EAST...IT MAY TAKE A
LITTLE LONGER TO GET THE SNOW TO DEVELOP (DUE TO THE DELAYED
ARRIVAL OF COLDER AIR) BUT SHOULD SEE SOME LIGHT SNOW LATE
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. THERE ARE TWO FACTORS
CONTRIBUTING TO LIMITED SNOWFALL AMOUNTS...THE MARGINAL DELTA-T
VALUES (WEAK LAPSE RATES) AND MUCH OF THE CLOUD BELOW THE DGZ. THE
KEWEENAW WOULD SEE THE BEST CHANCE FOR AN INCH OF SNOW DUE TO THE
HIGHER INVERSION HEIGHTS (5-7KFT)...ALTHOUGH THE WEAK LAPSE RATES
WILL LIMIT INTENSITY. EXPECT THE LAKE EFFECT PRECIPITATION TO FOCUS
OVER THE WEST-SOUTHWEST WIND AREAS ON THURSDAY...BEFORE DIMINISHING
AS WARM AIR ADVECTION INCREASES AND STRENGTHENS THE INVERSION BELOW
850MB. DEPENDING ON THE AMOUNT OF MIXING ON THURSDAY...IT COULD GET
A LITTLE GUSTY WITH GUSTS UP TO 20-25KTS.
THAT NEXT CLIPPER WILL MOVE MOVING ACROSS NORTHERN ONTARIO LATE
THURSDAY NIGHT AND FRIDAY...WHICH WILL SWEEP A COLD FRONT SOUTHEAST
ACROSS THE CWA FRIDAY AFTERNOON INTO FRIDAY EVENING. WILL SHOWING
INCREASING PRECIPITATION CHANCES AHEAD OF THE FRONT AS IT MOVES
ACROSS THE AREA. THERE IS SOME SUPPORT ALOFT...AS A SECONDARY
SHORTWAVE WILL DROP ACROSS THE AREA WITH THE FRONT...BUT THERE IS A
DECENT POCKET OF DRY AIR BETWEEN 925-750MB OVER THE SOUTHERN HALF
OF THE U.P. WHICH WILL LIKELY LIMIT PRECIPITATION CHANCES THERE.
ALSO...THAT AREA WITH THE DRY AIR AND WARMING WOULD PUT THE THERMAL
PROFILE THERE ABOVE FREEZING. BUT LOOKING AT THE WETBULB VALUES
WOULD INDICATE IF PRECIPITATION WOULD OCCUR...IT WOULD COOL BACK
BELOW FREEZING. THEREFORE AT THIS POINT...WILL KEEP PRECIPITATION
AS ALL SNOW AND ONLY HAVE AMOUNTS UNDER AN INCH FOR MOST AREAS
(AND A COUPLE INCHES OVER THE EAST).
FORECAST BECOMES A LITTLE UNCERTAIN FOR FRIDAY NIGHT INTO SATURDAY
BEHIND THE CLIPPER. WHILE ALL OF THE MODELS SHIFT THE WINDS TO THE
NORTHWEST BEHIND THE FRONT...THERE IS A SIGNIFICANT DIFFERENCE IN
850MB TEMPS. THE 00Z GFS AND PAST COUPLE OF RUNS HAVE BEEN
CONSISTENT IN DROPPING 850MB TEMPS TO -12C...WHILE RECENT RUNS OF
THE ECMWF/GEM ARE MUCH WARMER AND AROUND -6C THROUGH SATURDAY
NIGHT. THAT COLD AIR MAKES/BREAKS THE LAKE EFFECT POTENTIAL FOR
THIS WEEKEND IN THE NW WIND SNOW BELTS. WITH THE 12Z ECMWF ENSEMBLE
MEAN CLOSER TO THE ECMWF/GEM DETERMINISTIC RUNS...WILL TREND IN
THAT DIRECTION BUT STILL KEEP LOW CHANCE AND SLIGHT CHANCE POPS IN
THE FAVORED NW WIND AREAS. HIGH PRESSURE SLIGHTS THROUGH NORTHERN
ONTARIO ON SUNDAY...WHICH WILL SHIFT WINDS TO THE NORTHEAST AND
EVENTUALLY EASTERLY. SNOW STILL DEPENDS ON HOW COLD IT WILL
BE...BUT BOTH GEM/ECMWF DO SHOW 850MB TEMPS FALLING TOWARDS -12C ON
SUNDAY AND WILL SHOW CHANCE POPS IN THE NORTH CENTRAL AND KEWEENAW.
ANOTHER CLIPPER SYSTEM WILL APPROACH THE AREA ON MONDAY FROM THE
NORTHWEST AND WILL SHOW SLIGHT CHANCE POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE JAN 20 2015
EXPECT PREDOMINANT MVFR CONDITIONS THROUGH TAF PERIOD AT MOST OF THE
SITES AS LOW-LVL MOISTURE REMAINS TRAPPED UNDER PERSISTENT
SUBSIDENCE INVERSION. DRIER EASTERLY WIND AT KSAW COULD ALLOW FOR LOW
CLOUDS TO SCATTER OUT THROUGH THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE JAN 20 2015
A RELATIVELY TRANQUIL PERIOD IS EXPECTED INTO THURSDAY WITH WINDS
BELOW 30 KNOTS. HOWEVER...SW WINDS WILL INCREASE TO 30 KNOTS THU
NIGHT WITH A FEW GALE FORCE GUSTS POSSIBLE AS LOW PRESSURE MOVES
TOWARD JAMES BAY. WEST WINDS TO 30 KNOTS ARE EXPECTED TO CONTINUE
FRI INTO SAT AS WINDS VEER TO THE WEST AND THEN TO THE NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1255 PM EST TUE JAN 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST TUE JAN 20 2015
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW INTO
THE NRN GREAT LAKES BETWEEN A TROUGH FROM QUEBEC INTO THE NE CONUS
AND A RIDGE OVER WRN CANADA. QVECTOR DIV/SUBSIDENCE PREVAILED OVER
THE REGION IN THE WAKE OF A SHORTWAVE TROUGH MOVING INTO LOWER
MI. AT THE SFC...LIGHT VARIABLE WINDS CONTINUED OVER LAKE SUPERIOR
AND UPPER MICHIGAN ON THE SRN FLANK OF HIGH PRES OVER NRN ONTARIO.
RADAR SHOWED LES DIMINISHING OVER N CNTRL UPPER MI WITH MAINLY JUST
FLURRIES. THERE WAS ENOUGH OF A NRLY WIND COMPONENT ABOVE THE SFC TO
SUSTAIN THE LES/FLURRIES WELL INLAND. HOWEVER...AS THE WINDS
CONTINUED TO WEAKEN...THE SNOW WAS ALSO DISSIPATING.WITH 900 MB
TEMPS AROUND -12C...CONDITIONS REMAINED FAVORABLE FOR HIGHER SLR
VALUES ABOVE 30/1. OTHERWISE...CLOUDS OVER WEST/CNTRL UPPER MI HAS
KEPT TEMPS IN THE TEENS WHILE CLEARING OVER THE EAST HAS ALLOWED
TEMPS TO DROP TO 0 TO -10F.
TODAY...THE LINGERING LOW LEVEL MOISTURE AND COLD AIR WILL SUSTAIN
THE LIGHT LES. HOWEVER...CONFIDENCE IN WHERE ANY BANDS WILL DEVELOP
OR MOVE WITH THE LIGHT WINDS IS LOW. SO...ONLY CHANCE POPS WERE
MENTIONED FOR LOCATIONS FAVORED BY EAST FLOW...FROM NRN MARQUETTE
COUNTY INTO THE KEWEENAW. THE DRY EASTERLY FLOW SHOULD BRING MOSTLY
SUNNY SKIES TO THE EAST AND MAY ERODE SOME OF THE LOWER CLOUDS OVER
CENTRAL UPPER MICHIGAN. TEMPS WILL CLIMB TO AROUND SEASONAL
AVERAGES WITH HIGHS FROM THE UPPER TEENS EAST TO THE MID 20S WEST.
TONIGHT...THE HIGHER RES MODELS SUGGEST THAT MOST OF THE LINGERING
LES WILL REMAIN OFFSHORE BUT MAY MOVE BACK INTO THE KEWEENAW AS
WINDS BECOME LIGHT NORTHERLY. EXPECT THE LOWEST TEMPS OVER THE EAST
TO AROUND ZERO WHERE SKIES REMAIN MOSTLY CLEAR. THERE IS MORE
UNCERTAINTY WITH THE CLOUDS/TEMPS CENTRAL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 333 AM EST TUE JAN 20 2015
A BUILDING RIDGE OVER THE PACIFIC NORTHWEST AND WESTERN CANADA
TODAY WILL LEAD TO NORTHWESTERLY FLOW ALOFT AND SEND A SERIES OF
SHORTWAVES/CLIPPERS SOUTHEAST ACROSS THE GREAT LAKES AND EASTERN
CANADA. ALTHOUGH THESE CLIPPERS WILL BE BRINGING CANADIAN AIR ACROSS
THE REGION...THE COLDEST AIR WILL REMAIN LOCKED OVER HUDSON BAY.
THUS...EXPECT TEMPERATURES TO BE NEAR OR ABOVE NORMAL OVER THE
NEXT WEEK WITH OCCASIONAL PERIODS OF LIGHT SNOW OR FLURRIES WITH THE
CLIPPERS. BETWEEN THE CLIPPERS THERE MAY BE A FEW PERIODS OF VERY
LIGHT LAKE EFFECT SNOW...BUT 925/850MB TEMPS ARE FAIRLY MARGINAL AND
THE WIND FIELDS ARE CONSTANTLY FLUCTUATING TO SUPPORT MUCH MORE THAN
OCCASIONAL SHOWERS. ALL IN ALL...NOT MUCH IN THE WAY OF SIGNIFICANT
WEATHER FOR THE PERIOD.
THE AREA WILL BE BETWEEN SHORTWAVES ON WEDNESDAY (ONE WILL BE
TRACKING THROUGH SOUTHERN WISCONSIN AND ILLINOIS AND THE OTHER
THROUGH NORTHERN ONTARIO)...WHICH WILL LIMIT ANY LARGER SCALE
SUPPORT FOR PRECIPITATION. BUT A LOW LEVEL THERMAL TROUGH WILL
GRADUALLY DROP SOUTHEAST ACROSS THE CWA LATE TONIGHT THROUGH
WEDNESDAY NIGHT...LEADING TO WINDS GRADUALLY BECOMING NORTHWEST ON
WEDNESDAY BEFORE QUICKLY BACKING SOUTHWESTERLY THURSDAY AHEAD OF A
SLIGHTLY STRONGER SHORTWAVE AND CLIPPER THAT WILL MOVE THROUGH
NORTHERN ONTARIO ON FRIDAY. MODELS ARE STILL VARYING ON THE AMOUNT
OF COLD AIR...BUT THERE SHOULD BE ENOUGH TO PRODUCE SOME LIGHT
SNOW...ESPECIALLY OVER THE WEST AND KEWEENAW WHERE LIGHT
NORTHWESTERLY WINDS ARE EXPECTED. FARTHER EAST...IT MAY TAKE A
LITTLE LONGER TO GET THE SNOW TO DEVELOP (DUE TO THE DELAYED
ARRIVAL OF COLDER AIR) BUT SHOULD SEE SOME LIGHT SNOW LATE
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. THERE ARE TWO FACTORS
CONTRIBUTING TO LIMITED SNOWFALL AMOUNTS...THE MARGINAL DELTA-T
VALUES (WEAK LAPSE RATES) AND MUCH OF THE CLOUD BELOW THE DGZ. THE
KEWEENAW WOULD SEE THE BEST CHANCE FOR AN INCH OF SNOW DUE TO THE
HIGHER INVERSION HEIGHTS (5-7KFT)...ALTHOUGH THE WEAK LAPSE RATES
WILL LIMIT INTENSITY. EXPECT THE LAKE EFFECT PRECIPITATION TO FOCUS
OVER THE WEST-SOUTHWEST WIND AREAS ON THURSDAY...BEFORE DIMINISHING
AS WARM AIR ADVECTION INCREASES AND STRENGTHENS THE INVERSION BELOW
850MB. DEPENDING ON THE AMOUNT OF MIXING ON THURSDAY...IT COULD GET
A LITTLE GUSTY WITH GUSTS UP TO 20-25KTS.
THAT NEXT CLIPPER WILL MOVE MOVING ACROSS NORTHERN ONTARIO LATE
THURSDAY NIGHT AND FRIDAY...WHICH WILL SWEEP A COLD FRONT SOUTHEAST
ACROSS THE CWA FRIDAY AFTERNOON INTO FRIDAY EVENING. WILL SHOWING
INCREASING PRECIPITATION CHANCES AHEAD OF THE FRONT AS IT MOVES
ACROSS THE AREA. THERE IS SOME SUPPORT ALOFT...AS A SECONDARY
SHORTWAVE WILL DROP ACROSS THE AREA WITH THE FRONT...BUT THERE IS A
DECENT POCKET OF DRY AIR BETWEEN 925-750MB OVER THE SOUTHERN HALF
OF THE U.P. WHICH WILL LIKELY LIMIT PRECIPITATION CHANCES THERE.
ALSO...THAT AREA WITH THE DRY AIR AND WARMING WOULD PUT THE THERMAL
PROFILE THERE ABOVE FREEZING. BUT LOOKING AT THE WETBULB VALUES
WOULD INDICATE IF PRECIPITATION WOULD OCCUR...IT WOULD COOL BACK
BELOW FREEZING. THEREFORE AT THIS POINT...WILL KEEP PRECIPITATION
AS ALL SNOW AND ONLY HAVE AMOUNTS UNDER AN INCH FOR MOST AREAS
(AND A COUPLE INCHES OVER THE EAST).
FORECAST BECOMES A LITTLE UNCERTAIN FOR FRIDAY NIGHT INTO SATURDAY
BEHIND THE CLIPPER. WHILE ALL OF THE MODELS SHIFT THE WINDS TO THE
NORTHWEST BEHIND THE FRONT...THERE IS A SIGNIFICANT DIFFERENCE IN
850MB TEMPS. THE 00Z GFS AND PAST COUPLE OF RUNS HAVE BEEN
CONSISTENT IN DROPPING 850MB TEMPS TO -12C...WHILE RECENT RUNS OF
THE ECMWF/GEM ARE MUCH WARMER AND AROUND -6C THROUGH SATURDAY
NIGHT. THAT COLD AIR MAKES/BREAKS THE LAKE EFFECT POTENTIAL FOR
THIS WEEKEND IN THE NW WIND SNOW BELTS. WITH THE 12Z ECMWF ENSEMBLE
MEAN CLOSER TO THE ECMWF/GEM DETERMINISTIC RUNS...WILL TREND IN
THAT DIRECTION BUT STILL KEEP LOW CHANCE AND SLIGHT CHANCE POPS IN
THE FAVORED NW WIND AREAS. HIGH PRESSURE SLIGHTS THROUGH NORTHERN
ONTARIO ON SUNDAY...WHICH WILL SHIFT WINDS TO THE NORTHEAST AND
EVENTUALLY EASTERLY. SNOW STILL DEPENDS ON HOW COLD IT WILL
BE...BUT BOTH GEM/ECMWF DO SHOW 850MB TEMPS FALLING TOWARDS -12C ON
SUNDAY AND WILL SHOW CHANCE POPS IN THE NORTH CENTRAL AND KEWEENAW.
ANOTHER CLIPPER SYSTEM WILL APPROACH THE AREA ON MONDAY FROM THE
NORTHWEST AND WILL SHOW SLIGHT CHANCE POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE JAN 20 2015
EXPECT PREDOMINANT MVFR CONDITIONS THROUGH TAF PERIOD AT MOST OF THE
SITES AS LOW-LVL MOISTURE REMAINS TRAPPED UNDER PERSISTENT
SUBSIDENCE INVERSION. DRIER EASTERLY WIND AT KSAW COULD ALLOW FOR LOW
CLOUDS TO SCATTER OUT THROUGH THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 517 AM EST TUE JAN 20 2015
A RELATIVELY TRANQUIL PERIOD IS EXPECTED INTO THURSDAY WITH WINDS
BELOW 30 KNOTS. HOWEVER...SW WINDS WILL INCREASE TO 30 KNOTS THU
NIGHT WITH A FEW GALE FORCE GUSTS POSSIBLE AS LOW PRESSURE MOVES
TOWARD JAMES BAY. WEST WINDS TO 30 KNOTS ARE EXPECTED TO CONTINUE
FRI INTO SAT AS WINDS VEER TO THE WEST AND THEN TO THE NORTHWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
524 PM CST WED JAN 21 2015
.UPDATE...
ISSUED AT 512 PM CST WED JAN 21 2015
UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 308 PM CST WED JAN 21 2015
WATER VAPOR IMAGERY OVERLAID WITH A RAP H5 ANALYSIS THIS AFTERNOON
SHOWS A RATHER ACTIVE PATTERN. THE RIDGE ON THE WEST COAST IS
AMPLIFYING...WITH A BROAD TROUGH ACROSS MOST OF NOAM EAST OF THE
ROCKIES. WITHIN THIS THROUGH...THE MOST PROMINENT FEATURE IS THE
WAVE MOVING THROUGH THE 4 CORNERS REGION...BUT THIS WILL REMAIN WELL
SOUTH OF US. CLOSER TO HOME THE SHORTWAVE THAT BROUGHT THE SNOW IN
YESTERDAY IS NOW OFF OVER SRN MICHIGAN. THE PV WITH THIS WAVE
EXTENDS BACK TO THE WEST INTO A TROUGH WITH ITS BASE IN WYOMING.
WITHIN THIS...YOU WILL FIND YET ANOTHER EMBEDDED SHORTWAVE SLOWLY
MOVING SOUTH THROUGH SODAK. AS WE GO THROUGH TONIGHT THIS BAGGY
THROUGH WILL SAG SOUTH OF US...WITH SHORTWAVE RIDGING TAKING ITS
PLACE FOR THURSDAY. UNTIL THIS GENERAL TROUGHINESS CLEARS THE
AREA...WE WILL MAINTAIN THE CLOUDS WITH OCCASIONAL LIGHT
SNOW/FLURRIES...THOUGH NO ADDITIONAL ACCUMULATIONS ARE EXPECTED.
THE BIG QUESTION FOR THE SHORT TERM IS WHEN EXACTLY WILL THESE
CLOUDS CLEAR OUT. ON THE HEELS OF THE UPPER WAVE MOVING OUT WILL A
SFC RIDGE MOVING IN. THE SUBSIDENCE AND DRYING WITH THIS WILL HELP
CLEAR OUT THE CLOUDS. BELIEVE THE NAM BUFR SOUNDINGS ARE TOO MOIST
IN THE LOW LEVELS...SO FOLLOWED MORE OF A GFS IDEA WITH SKIES
CLEARING FROM N TO S TONIGHT....THOUGH WENT A BIT SLOWER THAN THE
NAM GIVEN THE HRRRS DEPICTION OF HOW THE STRATUS SHIELD WILL CLEAR
OUT THIS EVENING. WE WILL SOME CLEAR SKIES ON THURSDAY BEFORE
MID/HIGH CLOUDS INCREASE AGAIN ACROSS CENTRAL MN DURING THE
AFTERNOON IN RESPONSE TO A SHORTWAVE MOVING ACROSS SRN CANADA.
TEMPERATURES WILL BE THE TRICKIEST PART OF THE FORECAST AS THEY WILL
BE HIGHLY DEPENDENT ON CLOUD COVER. FOR PLACES THAT KEEP THE
CLOUDS...LOWS WILL STAY IN THE 20S. YOU LOSE YOUR CLOUDS...WELL WITH
LIGHT WINDS TEMP DROPS WILL BE OFF TO THE RACES...LIKELY SETTLING IN
THE SINGLE DIGITS IF ENOUGH TIME WITH CLEAR SKIES CAN HAPPEN. THIS
WOULD BE MOST LIKELY FOR CENTRAL MN. FOR THURSDAY...SW WINDS WILL BE
INCREASING THROUGH THE DAY. THIS WILL QUICKLY PUT AN END TO THE WEAK
CAA WE ARE SEEING THIS AFTERNOON...WITH HIGHS BACK IN THE 30S LIKELY
OUT IN THE MN RIVER VALLEY...WITH WARMER TEMPS STILL TO COME.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM CST WED JAN 21 2015
A CLIPPER SYSTEM WILL BE SLIDING EAST THROUGH THE SOUTHERN
CANADIAN PROVINCES BY THURSDAY NIGHT...BUT ESSENTIALLY ALL PRECIP
WILL STAY NORTH OF THE INTERNATIONAL BORDER. THE MAIN CONCERN FOR
OUR AREA IS WHETHER OR NOT ANY PRECIP WILL BE PRODUCED ALONG THE
COLD FRONTAL BOUNDARY ASSOCIATED WITH THIS SYSTEM THAT IS SET TO
DROP SOUTH THROUGH OUR AREA ON FRIDAY. MODELS GENERALLY AGREE ON
SQUEEZING OUT LIGHT PRECIP ALONG THIS FRONTAL BOUNDARY. THERMAL
PROFILES REMAIN WARM...SO ANY LIGHT PRECIP THAT DOES FALL WILL BE
A MIX OF SNOW...SLEET...AND RAIN.
THE OVERALL PATTERN IN THE LONG RANGE WILL CONSIST OF AN UPPER
RIDGE ACROSS WESTERN NORTH AMERICA AND A TROUGH ACROSS EASTERN
NORTH AMERICA. YET ANOTHER CLIPPER WILL DIVE SOUTHEAST THROUGH
CANADA THIS WEEKEND...BUT THIS SYSTEM LOOKS STRONGER AND THE
SHORTWAVE WILL AMPLIFY AS IT APPROACHES THE NORTHERN STATES. THE
LATEST GFS RUN INDICATES A SLIGHT SHIFT TO THE EAST WHICH WOULD
PUT WESTERN WI AND EXTREME EASTERN MN UNDER THE HEAVIEST
POTENTIAL...WHICH REMAINS AT ABOUT 0.20-0.30" OF LIQUID QPF. IN
THIS AREA...THERMAL PROFILES ARE INDICATIVE OF ALL SNOW HERE SO A
COUPLE OF INCHES OF ACCUMULATION REMAINS A POSSIBILITY.
HOWEVER...THIS SYSTEM IS STILL 3.5-4 DAYS AWAY SO MUCH CAN
CHANGE. ESPECIALLY BECAUSE THERE IS DECENT POTENTIAL FOR A STRONG
NOR`EASTER TO MOVE UP THE EAST COAST. THIS FEATURE WILL PLAY A
KEY PART IN THE EVOLUTION OF UPSTREAM FEATURES SO SHIFTS IN OUR
CLIPPER ARE CERTAINLY POSSIBLE.
AS WE HEAD INTO NEXT WEEK...THE WESTERN RIDGE WILL BASICALLY HOLD
FIRM AND THE ECMWF INDICATES ANOTHER LIGHT SNOWFALL EVENT POSSIBLE
FOR OUR AREA. THERE IS NOT MUCH AGREEMENT WITH THIS SYSTEM
HOWEVER...AS THE GFS IS MUCH STRONGER AND NORTHEAST OF OUR AREA
WITH THE MAIN PRECIP.
TEMPERATURES LOOK TO REMAIN ABOVE NORMAL THROUGH EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 512 PM CST WED JAN 21 2015
LOWER CEILINGS LOOK TO LINGER OVER THE FORECAST AREA THROUGH MUCH
OF TONIGHT UNTIL WE GET ONTO THE BACKSIDE OF THE UPPER TROUGH AND
SEE BETTER SUBSIDENCE WORK INTO THE AREA. THERE HAVE BEEN A FEW
HOLES IN THE LOWER DECK THIS AFTERNOON... SO SOME TEMPORARY
IMPROVEMENT IS POSSIBLE AT ALL SITES. ONLY INCLUDES THAT AT KAXN
FOR NOW... SINCE THE ONLY LARGE HOLE EVIDENT IN SATELLITE IMAGERY
IS UPSTREAM OF THERE AT THE CURRENT TIME. HOWEVER.. THE OTHER MN
SITES COULD SEE TEMPORARY IMPROVEMENT AT TIMES THROUGH EARLY
EVENING. MORE SUBSTANTIAL IMPROVEMENT AND EROSION OF THE LOW
CLOUDS IS EXPECTED LATE TONIGHT AND THURSDAY AS UPPER RIDGING
STARTS TO WORK IN AND WE FINALLY GET SOME BOUNDARY LAYER WINDS TO
KICK UP ON THE BACKSIDE OF THE SURFACE HIGH TO HELP MOVE THE LOW
LEVEL MOISTURE OUT OF THE REGION.
KMSP...TAF REFLECTS OVERALL EXPECTATIONS WITH IMPROVING
CONDITIONS LATER TONIGHT AND THURSDAY. IT REMAINS TO BE SEEN JUST
HOW QUICKLY THE LOWER CLOUDS WILL DEPART... AND COULD CERTAINLY
SEE TIMING VARY BY SEVERAL HOURS IN COMPARISON TO THE FORECAST...
WITH A SLOWER DEPARTURE SEEMING THE MORE LIKELY SCENARIO IF THINGS
DIFFER.
/OUTLOOK FOR KMSP/
THURSDAY OVERNIGHT...VFR. SOUTHWEST WIND 10 TO 15 KT.
FRIDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF
LIGHT RAIN OR SLEET. SOUTHWEST WIND 10 TO 20 KT BECOMING WEST.
FRIDAY NIGHT...MVFR CEILINGS POSSIBLE. WEST WIND 5 TO 15 KT.
SATURDAY...VFR. WEST WIND 5 TO 10 KT.
SATURDAY NIGHT AND SUNDAY. MVFR CEILINGS EXPECTED... IFR POSSIBLE.
MVFR OR IFR VISIBILITIES POSSIBLE... ESPECIALLY SUNDAY. SOUTHWEST
WIND 10 TO 15 KT BECOMING NORTHWEST 10 TO 20 KT SUNDAY.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...
SHORT TERM...MPG
LONG TERM...SPD
AVIATION...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
104 PM EST TUE JAN 20 2015
.SYNOPSIS...
PASSING UPPER LEVEL DISTURBANCES...AND MOISTURE...WILL LEAD TO
LINGERING FLURRIES INTO THIS AFTERNOON. LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED. TONIGHT AND MOST OF WEDNESDAY WILL BE
DRY AND SEASONABLY COLD...WITH WEAK HIGH PRESSURE IN CONTROL. A
FAST MOVING STORM SYSTEM WILL BRING A PERIOD OF LIGHT SNOW OR
FLURRIES WEDNESDAY NIGHT INTO EARLY THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
940 AM UPDATE...VISIBLE SATELLITE SHOWS SHALLOW LOW-LEVEL MOISTURE
AND STRATOCUMULUS CLOUDS THAT LINGERED OVER MUCH OF CENTRAL NY
AND MOST OF PA. A DRIER ARCTIC AIR MASS HAS SLIDE SOUTHWARD INTO
ONEIDA COUNTY AND HAS LED TO CLEARING. MODEL SOUNDINGS CONTINUE
TO SHOW MOISTURE TRAPPED UNDER AN INVERSION MOST AREAS WHICH
LOWERS DURING THE AFTERNOON. THE HRRR SUGGESTS CLEARING IN MOST
AREAS WITH THE NAM12 CONTINUING THE LOW CLDS ESP ACRS NE PA TO THE
CATSKILLS. LOOKING AT THE SATELLITE IMAGERY WILL HAVE PARTIAL
CLEARING WORKING S AND W DURING THE AFTERNOON. WILL KEEP MO CLDY
FROM KAVP TO KELM THRU AFTERNOON. FARTHER N AND E...THERE SHUD BE
SOME BREAKS AND NC NY WILL SEE MORE SUNSHINE. SINCE LOW-LEVEL
TEMPERATURES UNDER THE INVERSION WERE CLOSE TO THE MAX GROWTH FOR
ICE CRYSTALS IT IS NOT HARD FOR CLOUD COVER TO PRODUCE A FEW
FLURRIES AS THE AIR BLOWS UP THE HILLS. SO WILL KEEP SCT FLURRIES
UNTIL AFTERNOON.
340 AM UPDATE... LINGERING LOW-LVL MOISTURE UNDERNEATH AN 850-800
MB CAPPING INVERSION THIS MRNG...280-290 FLOW...AND FAST MOVG MID-
LVL S/WVS...WILL KEEP FLRYS/SCTD LGT SNOW SHWRS GOING THROUGH AT
LEAST 12-15Z...UNDERNEATH MAINLY CLOUDY SKIES.
STARTING DURG THE LATE MRNG AND EARLY AFTN HRS...SOME LOW-LVL
DRYING DOES ATTEMPT TO COME DOWN FROM THE N...WITH WEAK SFC
RIDGING BLDG DOWN FROM ONT/QUE. THUS...WE MAY SEE BREAKS OF
SUNSHINE DVLP BY AFTN...ALG WITH A CESSATION OF FLRYS/SNOW SHWRS.
IT WILL BE SEASONABLY COLD AGN TDY...WITH MAX TEMPS MOSTLY IN THE
20S...EXCEPT FOR A FEW LWR 30S IN THE WYO/LACK VLYS OF NE PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
350 AM UPDATE... TNT AND MOST OF WED WILL BE QUIET/DRY...WITH ABV
MENTIONED SFC HIGH PRES BLDG ACRS UPSTATE NY AND NRN NEW ENG.
CLEAR TO PTLY CLDY SKIES...SPCLY OVER OUR NRN ZNS TNT...ALG WITH A
CHILLY AMS AND SNOW COVER...WILL LEAD TO LOW TEMPS IN THE SINGLE
DIGITS OVER MUCH OF CNY/NE PA. SOME OF OUR NORMALLY COLDER VLYS
COULD SEE SUB-ZERO READINGS BY DAYBREAK WED. BY WED AFTN...HIGHS
SHOULD RECOVER INTO THE 20S-LWR 30S ONCE AGN...UNDERNEATH
INCREASING MID TO HIGH-LVL CLDNS.
WED NGT INTO EARLY THU...WE CONTINUE TO WATCH A S/WV EMERGING FROM
THE NRN PLAINS/UPR LKS RGNS...THEN COMING EWD ACRS NY/PA. AN
ASSOCD WEAK CLIPPER-TYPE SFC LOW IS PROGGED TO TRACK EWD IN
TANDEM...LIKELY ACRS THE OH VLY/PA/NJ. A NARROW SWATH OF LGT SNOW
IS EXPECTED TO ACCOMPANY THIS SYSTEM. HOWEVER...THE EXACT LATITUDE
OF THIS STRIPE OF LGT SNOW REMAINS IN QUESTION (THE NAM FARTHEST N
THROUGH MUCH OF CNY...WHILE THE EC IS FARTHEST S...MOSTLY POINTS
FROM PA SWD). FOR NOW...WE`VE GONE WITH A BLEND OF OUR EXISTING FCST
AND A MODEL COMPROMISE...WHICH WOULD BRING A GENERAL 0.5-1.5" OF
SNOW TO MOST OF THE FA OVERNIGHT WED INTO THU MRNG. LGT SNOW
SHOULD TAPER OFF TO SCTD SNOW SHWRS/FLRYS THU AFTN...AS THE MAIN
FORCED ASCENT SHIFTS EWD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PD FEATURES CONTD BLO NRML TEMPS...AND A NEAR MISS BY A CPL DVLPG
CSTL SYSTEMS. DETAILS...FRI NGT BEGINS THE PD WITH DRY AIR OUT AHD
OF SAT/S DVLPG CSTL SYSTEM. BOTH THE EURO AND GFS AGREE TO KEEP
THE CNTR OF THE DEEPENING STORM WELL EAST OF THE NJ CST DURING SAT
PERHAPS JUST BRUSHING THE NEPA ZONES WITH SOME LGT SNOW OTRW
HAVING LTL EFFECT IN THE AREA. ARCTIC FNT DROPS IN BHD THE STORM
SAT NGT AND SUNDAY BRINGING SOME VERY CHILLY AIR ONCE AGAIN...WITH
A N TO NE FLOW LIMITING THE LE...AND MAXIMIZING THE CAA. BEST
CHANCE FOR LE SUNDAY WILL ONCE AGAIN BE OVER THE FINGER LAKES
REGION. ARCTIC HI BLDS IN FOR MON...BRINGING PSBL BLO ZERO TEMPS
ONCE AGAIN...ESP FOR THE NE ZONES. MODELS...ESP THE EURO...DVLP
ANOTHER DEEP CSTL ON TUE...BUT ONCE AGAIN TRACK THE CNTR WELL EAST
OF THE FCST AREA RESULTING IN LTL EFFECT IN THE FCST.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
WEAK CLIPPER WILL PASS SOUTH OF THE AREA TNGT MISSING THE TAF
SITES. HWVR...STILL SOME LL MOISTURE...PERHAPS ENHANCED BY THE
LAKES...OVER THE AREA...ESP LTR TNGT WHICH SHD BRING SOME OCNL
MVFR CIGS TO SOME OF THE NY STATIONS. NEXT SW APRCHS FOR LTR
WED...AHD OF THE SYSTEMS EARLY WED WILL FEATURE HI CIGS AND NO
RESTRICTIONS. WEAK LL GRADIENT WILL RESULT IN LGT WINDS THRU THE
TAF PD.
OUTLOOK...
WED NGT THU...MVFR PSBL IFR IN SNOW SHWRS AS CLIPPER MVES THRU.
FRI/SAT...VFR.
SUN...MVFR AND OCNL IFR PSBL IN SNOW SHWRS...ESP IN NY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/MLJ
NEAR TERM...DJN/MLJ
SHORT TERM...MLJ
LONG TERM...DGM
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
955 AM EST TUE JAN 20 2015
.SYNOPSIS...
PASSING UPPER LEVEL DISTURBANCES...AND MOISTURE...WILL LEAD TO
LINGERING FLURRIES INTO THIS AFTERNOON. LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED. TONIGHT AND MOST OF WEDNESDAY WILL BE
DRY AND SEASONABLY COLD...WITH WEAK HIGH PRESSURE IN CONTROL. A
FAST MOVING STORM SYSTEM WILL BRING A PERIOD OF LIGHT SNOW OR
FLURRIES WEDNESDAY NIGHT INTO EARLY THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
940 AM UPDATE...VISIBLE SATELLITE SHOWS SHALLOW LOW-LEVEL MOISTURE
AND STRATOCUMULUS CLOUDS THAT LINGERED OVER MUCH OF CENTRAL NY
AND MOST OF PA. A DRIER ARCTIC AIR MASS HAS SLIDE SOUTHWARD INTO
ONEIDA COUNTY AND HAS LED TO CLEARING. MODEL SOUNDINGS CONTINUE
TO SHOW MOISTURE TRAPPED UNDER AN INVERSION MOST AREAS WHICH
LOWERS DURING THE AFTERNOON. THE HRRR SUGGESTS CLEARING IN MOST
AREAS WITH THE NAM12 CONTINUING THE LOW CLDS ESP ACRS NE PA TO THE
CATSKILLS. LOOKING AT THE SATELLITE IMAGERY WILL HAVE PARTIAL
CLEARING WORKING S AND W DURING THE AFTERNOON. WILL KEEP MO CLDY
FROM KAVP TO KELM THRU AFTERNOON. FARTHER N AND E...THERE SHUD BE
SOME BREAKS AND NC NY WILL SEE MORE SUNSHINE. SINCE LOW-LEVEL
TEMPERATURES UNDER THE INVERSION WERE CLOSE TO THE MAX GROWTH FOR
ICE CRYSTALS IT IS NOT HARD FOR CLOUD COVER TO PRODUCE A FEW
FLURRIES AS THE AIR BLOWS UP THE HILLS. SO WILL KEEP SCT FLURRIES
UNTIL AFTERNOON.
340 AM UPDATE... LINGERING LOW-LVL MOISTURE UNDERNEATH AN 850-800
MB CAPPING INVERSION THIS MRNG...280-290 FLOW...AND FAST MOVG MID-
LVL S/WVS...WILL KEEP FLRYS/SCTD LGT SNOW SHWRS GOING THROUGH AT
LEAST 12-15Z...UNDERNEATH MAINLY CLOUDY SKIES.
STARTING DURG THE LATE MRNG AND EARLY AFTN HRS...SOME LOW-LVL
DRYING DOES ATTEMPT TO COME DOWN FROM THE N...WITH WEAK SFC
RIDGING BLDG DOWN FROM ONT/QUE. THUS...WE MAY SEE BREAKS OF
SUNSHINE DVLP BY AFTN...ALG WITH A CESSATION OF FLRYS/SNOW SHWRS.
IT WILL BE SEASONABLY COLD AGN TDY...WITH MAX TEMPS MOSTLY IN THE
20S...EXCEPT FOR A FEW LWR 30S IN THE WYO/LACK VLYS OF NE PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
350 AM UPDATE... TNT AND MOST OF WED WILL BE QUIET/DRY...WITH ABV
MENTIONED SFC HIGH PRES BLDG ACRS UPSTATE NY AND NRN NEW ENG.
CLEAR TO PTLY CLDY SKIES...SPCLY OVER OUR NRN ZNS TNT...ALG WITH A
CHILLY AMS AND SNOW COVER...WILL LEAD TO LOW TEMPS IN THE SINGLE
DIGITS OVER MUCH OF CNY/NE PA. SOME OF OUR NORMALLY COLDER VLYS
COULD SEE SUB-ZERO READINGS BY DAYBREAK WED. BY WED AFTN...HIGHS
SHOULD RECOVER INTO THE 20S-LWR 30S ONCE AGN...UNDERNEATH
INCREASING MID TO HIGH-LVL CLDNS.
WED NGT INTO EARLY THU...WE CONTINUE TO WATCH A S/WV EMERGING FROM
THE NRN PLAINS/UPR LKS RGNS...THEN COMING EWD ACRS NY/PA. AN
ASSOCD WEAK CLIPPER-TYPE SFC LOW IS PROGGED TO TRACK EWD IN
TANDEM...LIKELY ACRS THE OH VLY/PA/NJ. A NARROW SWATH OF LGT SNOW
IS EXPECTED TO ACCOMPANY THIS SYSTEM. HOWEVER...THE EXACT LATITUDE
OF THIS STRIPE OF LGT SNOW REMAINS IN QUESTION (THE NAM FARTHEST N
THROUGH MUCH OF CNY...WHILE THE EC IS FARTHEST S...MOSTLY POINTS
FROM PA SWD). FOR NOW...WE`VE GONE WITH A BLEND OF OUR EXISTING FCST
AND A MODEL COMPROMISE...WHICH WOULD BRING A GENERAL 0.5-1.5" OF
SNOW TO MOST OF THE FA OVERNIGHT WED INTO THU MRNG. LGT SNOW
SHOULD TAPER OFF TO SCTD SNOW SHWRS/FLRYS THU AFTN...AS THE MAIN
FORCED ASCENT SHIFTS EWD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
XTNDD PD WILL BE QUIET AS LTL OVERALL CHG IN THE PTRN IS
XPCTD...AND NO MAJOR SYSTEMS FORECAST. GNRL NW FLOW CONTS EARLY IN THE
PD SO SOME MSTLY LGT LE CANNOT BE RULED OUT AT ANY TIME...BUT THE
BEST CHANCE WILL BE THU NGT AND FRI BEFORE A SFC HIPRES BLDS IN.
WITH THIS HIGH AND INTO THE SAT...FLOW IS MORE WSW SO ANY LE COULD
BE MAINLY NORTH OF THE FCST AREA. SAT NGT A SHRP WV AND STRONG
COLD FNT PASS INCRSG THE CHANCE FOR LE AND BRINGING MUCH COLDER
AIR BACK TO THE REGION.
WITH LTL GOING ON...GNRLY FLWD HPC GUID FOR THE XTNDD PD.THAT
SEEMED TO BRING US INTO GOOD COLLABORATION WITH MOST OF THE
SURROUNDING OFFICES AS WELL.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
GENERALLY VFR AT KAVP. MVFR CIGS AT NY TERMINALS WILL IMPROVE TO
VFR FIRST AT KSYR/KRME/KELM BY MID MORNING. AT KSYR AND KBGM
IMPROVEMENT TO VFR LIKELY TO TAKE LONGER AND PERHAPS NOT UNTIL
AFTER 21Z. VFR TONIGHT WITH A FEW HIGH CLOUDS.
NORTHWEST WINDS AROUND 10 KTS THIS MORNING, BECOMING LIGHT
NORTHWEST THIS AFTERNOON. NEAR CALM OR LIGHT NORTHERLY WINDS AT 5
KTS OR LESS TONIGHT.
OUTLOOK...
TUE/WED...VFR.
WED NGT THU...MVFR PSBL IFR IN SNOW SHWRS AS CLIPPER MVES THRU.
FRI/SAT...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/MLJ
NEAR TERM...DJN/MLJ
SHORT TERM...MLJ
LONG TERM...DGM
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
607 PM CST WED JAN 21 2015
.UPDATE...
ISSUED AT 608 CST WED JAN 21 2015
SURFACE HIGH PRESSURE OVER CENTRAL NORTH DAKOTA WILL MOVE
SOUTHEAST TONIGHT AS LOW PRESSURE DEEPENS IN THE LEE OF THE
NORTHERN AND CANADIAN ROCKIES. FOR THE EARLY EVENING UPDATE THE
MAIN CHANGES WERE ADJUSTING SKY COVER BASED ON LATEST SATELLITE
IMAGERY. ALSO UPDATED LATEST SENSIBLE WEATHER ELEMENTS. NO OTHER
CHANGES WERE NECESSARY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 235 PM CST WED JAN 21 2015
FOCUS IN THE SHORT TERM IS ON THE EXITING SHORT WAVE EARLY THIS
AFTERNOON AND THE WARM AIR ADVECTION THURSDAY.
CURRENT OBSERVATIONS SHOW LITTLE IN THE WAY OF SNOW ACROSS CENTRAL
AND WESTERN NORTH DAKOTA EARLY THIS AFTERNOON. RADAR SHOWS SOME
MINOR REFLECTIVITIES OVER THE SOUTH CENTRAL. THUS THE CURRENT
FORECAST OF FLURRIES EXITING THE SOUTH BY 23 UTC IS STILL ON TRACK.
THE LATEST 12 UTC RUNS OF THE ECMWF AND GFS SHOW RISING HEIGHTS AND
EVEN ABOVE ZERO TEMPERATURES AT 850 MB BY 06 UTC THURSDAY ACROSS THE
WEST. WOULD EXPECT OVERNIGHT LOWS TO OCCUR EARLIER THAN USUAL
ESPECIALLY ACROSS THE WEST AS TEMPERATURES WILL BE CLIMBING BEFORE
SUNRISE THURSDAY.
DESPITE WARM AIR ADVECTION THURSDAY...HAVE STAYED RELATIVELY
CONSERVATIVE WITH AFTERNOON HIGHS AS THE CURRENT SNOW PACK SHOULD
MODERATE TEMPERATURES A BIT. WHILE TEMPERATURES MAY BE MODERATED...DO
EXPECT SIGNIFICANT MELTING OF THE SEASONABLY LOW SNOW PACK
THURSDAY...ESPECIALLY SOUTH AND WEST WHERE MORE SUNSHINE WILL BE
IN PLACE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 235 PM CST WED JAN 21 2015
THE LONG TERM FEATURES INCLUDE ABOVE NORMAL TEMPERATURES...DRY
CONDITIONS...AND A SERENE WEATHER PATTERN ACROSS NORTH DAKOTA.
SPLIT FLOW ALOFT ENSUES BEHIND AN OUTGOING SHORTWAVE ON
FRIDAY...WHILE A H500 RIDGE STARTS TO BUILD OVER THE ROCKY
MOUNTAINS AND NORTHERN HIGH PLAINS FOR THE BEGINNING OF THE
WEEKEND. THIS SETUP FAVORS THE DEVELOPMENT OF CHINOOK FLOW
ORIGINATING FROM THE NORTHERN ROCKIES...USHERING IN A WARM AND DRY
AIRMASS OVER THE REGION. OVER THE LAST FEW WEEKS...THE OVERALL
GUIDANCE HAS DEMONSTRATED A COLD BIAS WITH THE WESTERLY
FLOW...DECENT BOUNDARY LAYER MIXING AND BARE GROUND. HAVE UTILIZED
THE BIAS CORRECTION...WHICH WARMS UP MAXIMUM TEMPERATURES FRIDAY
THROUGH MONDAY INTO THE MID 30S TO LOWER 40S. CHANCES FOR
PRECIPITATION WILL BE LIMITED THROUGH THE LONG TERM...WITH THE
BEST CHANCE FOR ANY PRECIPITATION BEING ACROSS THE NORTH AS A
CLIPPER SYSTEM CLIPS THE NORTHERN TIER OF THE STATE ON WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 608 PM CST WED JAN 21 2015
A BAND OF MVFR CLOUDS ACROSS WESTERN NORTH DAKOTA WILL AFFECT KISN
AND KDIK THROUGH AROUND 02 UTC. AND SHOULD MOVE INTO KMOT BY
AROUND 02 UTC AND REMAIN THROUGH AROUND 06 UTC. UNCLEAR WHETHER
THE MVFR CEILINGS MAKE IT TO KBIS AND KJMS. LATEST HRRR INDICATES
LOWER CEILINGS BREAKING UP AS THEY MOVE EAST...SO FOR NOW KEPT
THEM OUT OF KBIS AND KJMS BUT WILL MONITOR. SOUTH TO SOUTHWEST
SURFACE FLOW WILL INCREASE LATE TONIGHT AND THURSDAY. COULD SEE
PATCHY FOG KBIS-KJMS LATER TONIGHT AFTER VFR CEILINGS MOVE OUT AND
BEFORE SURFACE WINDS INCREASE. AGAIN TOO MUCH UNCERTAINTY AT THIS
TIME TO ADD TO THESE TAF FORECASTS. VFR CEILINGS EXPECTED THURSDAY
WITH INCREASING MID AND HIGH LEVEL CLOUDS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...MM
LONG TERM...KS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
425 PM EST TUE JAN 20 2015
.SYNOPSIS...
A SERIES OF WEATHER DISTURBANCES WILL MOVE EAST ACROSS THE OHIO
VALLEY THROUGH WEDNESDAY NIGHT...BRINGING OCCASIONAL CHANCES FOR
LIGHT RAIN AND SNOW. SLIGHTLY COOLER AIR WILL MOVE INTO THE REGION
THROUGH THE REST OF THE WEEK...WITH HIGH PRESSURE PROVIDING DRY
CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
WITH ONE SHORTWAVE NOW OFF TO THE EAST...THE ILN FORECAST AREA IS
NOW LOCATED UNDER A SMALL AREA OF RIDGING ALOFT. THE TEMPERATURE
GRADIENT REMAINS VERY TIGHT...DUE TO SEVERAL FACTORS. THE CLOUDS
AND SNOW PACK IN THE NORTH ARE HELPING TO KEEP CONDITIONS
COOLER...WHILE VERY CLEAR SKIES IN THE SOUTH HAVE ALLOWED FOR A
BIG DIURNAL INCREASE IN TEMPERATURES. THERE ALSO REMAINS A WEAK
AND NEBULOUS SURFACE BOUNDARY...STRETCHED SOMEWHERE ACROSS THE
REGION.
THIS TEMPERATURE GRADIENT SHOULD RELAX SLIGHTLY OVERNIGHT...AS
ATTENTION TURNS TO THE NEXT SHORTWAVE MOVING IN FROM THE WEST
(WHICH WILL BE DISCUSSED IN THE SHORT TERM SECTION). EVEN THOUGH
CLOUD COVER WILL BE INCREASING...TEMPERATURES ARE EXPECTED TO DROP
TO NEAR FREEZING (WITH MID 30S IN THE FAR SOUTH). WITH DEWPOINTS
CURRENTLY IN THE LOWER TO MID 30S AND AT LEAST SOME IMPACT
EXPECTED FROM THE INCOMING CLOUDS...MIN TEMPS WERE RAISED SLIGHTLY
FROM THE PREVIOUS FORECAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
THE FIRST PERIOD OF THE SHORT TERM FORECAST WILL COME WITH A FEW
ITEMS WORTH DISCUSSING. ANOTHER SHORTWAVE IN THE QUICK WESTERLY
FLOW WILL APPROACH THE OHIO VALLEY VERY EARLY WEDNESDAY MORNING.
AS THIS OCCURS...THE LEFT EXIT REGION OF A 100-PLUS KNOT UPPER JET
WILL BE POSITIONING ITSELF FAVORABLY...AS ISENTROPIC LIFT ALSO
DEVELOPS NEAR 700MB. COMBINED TOGETHER...THE ILN FORECAST AREA
WILL BE IN AN AREA OF DEVELOPMENTAL PRECIPITATION...WHICH IS
FORECAST TO EXPAND AND STRENGTHEN AS IT MOVES EAST-NORTHEAST
THROUGH OHIO AND INTO PENNSYLVANIA. POPS WERE RAISED TO LIKELY IN
THE NORTHERN AND NORTHEASTERN SECTIONS OF THE FORECAST AREA...WITH
SOME TIMING ADJUSTMENTS BASED ON THE 12Z NAM AND LATEST RAP MODEL
RUNS.
BEHIND THE AXIS OF THE SHORTWAVE...TEMPERATURES JUST OFF THE
SURFACE WILL BEGIN COOLING...AS WINDS SHIFT FROM SOUTHERLY TO
WESTERLY. THERE IS LITTLE REFLECTION OF THIS AT THE
SURFACE...AS THE PRESSURE PATTERN WILL REMAIN VERY
NEBULOUS...THOUGH THE LIGHT WINDS MAY SHIFT SLIGHTLY TO THE WEST.
BY LATE MORNING...LAPSE RATES WILL BE FAIRLY STEEP...AND WHETHER
PRECIPITATION FALLS AS RAIN OR SNOW WILL LARGELY BE ABLE TO BE
DEFINED BY SURFACE TEMPERATURE. THE TEMPERATURE GRADIENT WILL
REMAIN SHARP...SO A MIX OF PRECIPITATION TYPES IS LIKELY AS
CONDITIONS WARM AND COOL.
HOWEVER...JUST AHEAD OF THE SHORTWAVE...A SMALL WARM AND SATURATED
LAYER WILL REMAIN IN PLACE NEAR 925MB. PRECIPITATION COMING OUT OF
THIS LAYER WILL LIKELY BE LIQUID...NECESSITATING A CAREFUL LOOK AT
SURFACE TEMPERATURES FOR WEDNESDAY MORNING. BASED ON THE
ADJUSTMENTS DESCRIBED IN THE NEAR TERM DISCUSSION...ONLY A SMALL
SECTION OF THE FORECAST AREA APPEARS LIKELY TO FALL INTO THE
30-32 DEGREE RANGE...GENERALLY IN WEST CENTRAL AND CENTRAL OHIO.
IN FACT...SOME MODELS ALLOW THESE LOCATIONS TO REMAIN AT OR ABOVE
THE FREEZING MARK. HOWEVER...THERE IS ENOUGH UNCERTAINTY IN THE
TEMPERATURE FORECAST TO ALLOW FOR A CHANCE OF FREEZING
RAIN...ESPECIALLY AS THE PRECIPITATION IS IN THE FIRST FEW HOURS
OF ITS DEVELOPMENT. COMING OUT OF A FEW RELATIVELY WARM
DAYS...ANTECEDENT CONDITIONS FOR ICING ARE NOT FAVORABLE...AND
HAZARDOUS CONDITIONS ARE UNLIKELY. HOWEVER...IF SURFACE
TEMPERATURES AND DEWPOINTS FALL OFF MORE THAN FORECAST DURING THE
OVERNIGHT HOURS...THIS LINE OF THINKING WILL NEED TO BE REVISITED.
FOR THE GRIDS...ANY MENTION OF FREEZING RAIN WAS LIMITED TO JUST A
CHANCE...AND ICE ACCUMULATION GRIDS WERE KEPT BLANK. SNOW
ACCUMULATIONS OF A FEW TENTHS OF AN INCH WILL BE POSSIBLE IN THE
FAR NORTHERN TIER OF ILN COUNTIES...ROUGHLY ALONG AND NORTH OF A
LINE FROM WAPAKONETA TO NEWARK.
A MIX OF RAIN AND SNOW MAY CONTINUE INTO THE DAY FOR THE NORTHERN
HALF OF THE FORECAST AREA...AT LEAST AFTER A BRIEF LULL FOLLOWING
THE CURVED BAND AHEAD OF THE SHORTWAVE. ALL OF THE MODELS SUGGEST
A SECOND WAVE MOVING INTO THE AREA AFTER 18Z (JUST SOUTH OF THE
WEAKENING 700MB LOW)...WITH GENERALLY LIGHT PRECIPITATION AMOUNTS.
THOUGH DRY CONDITIONS ARE GENERALLY EXPECTED AFTER 00Z...REMAINING
LOW-LEVEL MOISTURE COULD ALLOW FOR SOME FLURRIES TO CONTINUE
LONGER THAN CURRENTLY FORECAST.
NORTHERN STREAM INFLUENCE OVER THE OHIO VALLEY WILL WANE MARKEDLY
BY THURSDAY...WITH AN ELONGATED WEST-TO-EAST AREA OF HIGH PRESSURE
STRETCHING ACROSS THE REGION...CAUGHT IN BETWEEN LOW PRESSURE
SYSTEMS WELL TO THE NORTH AND SOUTH. WNW FLOW BEHIND THE SHORTWAVE
WILL TURN ADVECTION TO THE COOL SIDE...LEADING TO A DROP IN
TEMPERATURES ON THURSDAY. SKY GRIDS WERE INCREASED THROUGH THIS
PERIOD...AS IT NOW APPEARS UNLIKELY THAT SIGNIFICANT BREAKS IN THE
LOW-LEVEL MOISTURE WILL DEVELOP UNTIL THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL START OUT THE LONG TERM PERIOD. FRIDAY EVENING
INTO FRIDAY NIGHT A SYSTEM WILL MOVE JUST SE OF THE FA. THIS WILL
BRING A CHANCE OF PRECIPITATION TO FAR SE PORTIONS OF THE REGION.
THIS SYSTEM MOVES OUT OF THE REGION BY SATURDAY. SATURDAY AFTERNOON
INTO SATURDAY NIGHT SOME LIGHT PRECIPITATION WILL BE POSSIBLE WITH
WINDS OFF OF LAKE MICHIGAN. KEPT MENTION TO A SLIGHT CHANCE AT THIS
TIME.
MODELS ARE NOT IN AGREEMENT ON A SYSTEM THAT IS EXPECTED TO MOVE
THROUGH THE AREA SUNDAY INTO MONDAY. THE GFS KEEPS MOST OF THE
PRECIPITATION SOUTH OF THE AREA WITH THIS SYSTEM WHILE THE ECMWF
LINGERS PRECIPITATION ACROSS THE AREA THROUGH ALMOST THE ENTIRE
SUNDAY TO MONDAY TIME FRAME. WENT CLOSER TO THE ECMWF SOLUTION
HOWEVER KEPT PRECIPITATION CHANCES CONFINED TO THE CHANGE CATEGORY
FOR MOST LOCATIONS AT THIS TIME. TEMPERATURES WILL BE COOL ENOUGH
THAT ANY PRECIPITATION THAT DOES OCCUR SUNDAY INTO MONDAY WILL BE IN
THE FORM OF SNOW. AFTER THIS TIME HIGH PRESSURE WILL BUILD INTO THE
AREA FOR TUESDAY.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
THE FORECAST AREA WILL BE IN A LULL IN TERMS OF CLOUD COVER AND
PRECIPITATION CHANCES FOR THE REMAINDER OF THIS AFTERNOON. A
BOUNDARY WAS LOCATED ACROSS THE NORTHERN TAF SITES. WILL HAVE TO
WATCH IF LOW LEVEL MOISTURE SNEAKS INTO THE KCMH/KLCK TERMINALS
ON A NORTH/NORTHEAST LOW LEVEL WIND.
FOR TONIGHT...ANOTHER EMBEDDED DISTURBANCE WITHIN THE FLOW ALOFT
WILL MOVE QUICKLY EAST TOWARD OUR AREA. MODELS SUGGEST THAT A WEAK
FRONTAL BOUNDARY WILL PASS FROM WEST TO EAST OVER OUR REGION WHILE
LINGERING BOUNDARY NEAR OUR NORTHERN TERMINALS BECOMES A QUASI-
WARM FRONT. AN INCREASING LOW LEVEL JET AND ISENTROPIC LIFT SHOULD
ALLOW PRECIPITATION TO BREAK OUT BETWEEN KDAY AND KCMH/KLCK
BETWEEN 06Z AND 12Z...EXPANDING IN COVERAGE AS IT LIFTS OUT OF THE
AREA. LOW LEVEL MOISTURE WILL INCREASE OVERNIGHT...NOT ONLY FROM
THE NORTH BUT FROM THE NORTHWEST BEHIND THE WEST TO EAST MOVING
BOUNDARY. ALL LOCATIONS SHOULD DROP INTO MVFR CONDITIONS WITH THE
NORTHERN TAF SITES OF KDAY/KCMH/KLCK HAVING THE BEST CHANCE OF
SEEING IFR CEILINGS. THE THREAT FOR PCPN (RAIN/SNOW MIXED) IS
HIGHEST AT THE KCMH/KLCK TERMINALS AND HAVE PLACED SOME IFR VSBYS
AT THESE SITES BETWEEN 09Z AND 12Z.
ON WEDNESDAY...FAST MOVING DISTURBANCE WILL SHEAR AS IT HEADS
EAST. LOW LEVEL CLOUDS WILL LINGER WITH PERHAPS CEILINGS LIFTING
BACK UP INTO THE MVFR CATEGORY ALL LOCATIONS BY 18Z. SOME
SCATTERED SNOW SHOWERS MAY DEVELOP LATE IN THE DAY...BUT THIS WILL
BE LOOKED AT IN MORE DETAIL WITH THE NEXT TAF ISSUANCE.
OUTLOOK...MVFR/IFR CEILINGS AND MVFR VISIBILITIES LIKELY WEDNESDAY
NIGHT INTO THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...HICKMAN
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
625 PM CST WED JAN 21 2015
.UPDATE...
ADJUSTED PRECIPITATION CHANCES UPWARDS IN MOST LOCATIONS THIS
EVENING. DELAYED SNOW BEGINNING TIMES 1 TO 3 HOURS IN MANY
LOCATIONS TONIGHT.
&&
.DISCUSSION...
ACCUMULATING SNOW IS EXPECTED TONIGHT INTO THURSDAY MORNING
ACROSS MUCH OF THE AREA.
ONGOING WINTER STORM WARNING AND WINTER WEATHER ADVISORY ARE IN
FINE SHAPE AND WILL NOT ALTER. NOT SURE THE NORTHERN PART OF THE
WARNING AREA UP TOWARDS GAGE...WOODWARD...AND BUFFALO WILL RECEIVE
4 INCHES OR MORE OF SNOW...BUT NOT CONFIDENT ENOUGH TO MAKE
CHANGES AT THIS TIME. TOTAL SNOW AMOUNTS WERE NOT SIGNIFICANTLY
ALTERED. FAR WESTERN OKLAHOMA WILL LIKELY HAVE THE HIGHEST AMOUNTS
OF SNOW...4 TO 6 INCHES...IF NOT LOCALLY MORE.
PRECIPITATION IS EXPANDING IN COVERAGE AND INTENSITY ACROSS THE
AREA BASED ON LATEST RADARS. LOW LEVELS REMAIN RATHER DRY AND
WARM...SO PRECIPITATION AT THE GROUND HAS BEEN SLOW TO
MATERIALIZE. SOME LIGHT RAIN/SPRINKLES HAVE BEEN REPORTED AT
THE GROUND. NO SNOW REPORTS HAVE BEEN RECEIVED AT THE GROUND IN
THE NORMAN FORECAST OFFICE WARNING AREA...THOUGH WOULD NOT BE
SURPRISED IF LOCATIONS NEAR AND WEST OF A ARNETT TO CHEYENNE LINE
HAVE ALREADY SWITCHED OVER TO SNOW WHERE MESONET SURFACE
TEMPERATURES HAVE DROPPED BELOW 35 DEGREES F.
STILL BELIEVE A TRANSITION FROM RAIN TO SNOW WILL OCCUR WEST TO
EAST ACROSS THE AREA TONIGHT. BASED ON LATEST HRRR/RAP13 WET BULB
SURFACE TEMPERATURES...DELAYED THE TRANSITION TIMES A FEW HOURS IN
MANY LOCATIONS.
A HEAVIER PRECIPITATION BAND MAY BE DEVELOPING NEAR I-40 WEST OF
EL RENO. IF THIS BAND PERSISTS AND THE AIR COOLS...THIS MAY CHANGE
OVER TO A MODERATE TO HEAVY BAND OF SNOW LATER THIS EVENING.
LATEST HRRR RUNS SEEM TO HAVE A DECENT HANDLE ON THIS BAND. WILL
CLOSELY MONITOR.
PRODUCTS HAVE BEEN UPDATED.
MBS
&&
.PREV DISCUSSION... /ISSUED 536 PM CST WED JAN 21 2015/
DISCUSSION...
THE 00Z AVIATION DISCUSSION FOLLOWS....
AVIATION...
A LARGE STORM SYSTEM WILL BRING WIDESPREAD RA AND SN TO MOST OF OK
AND N TX TONIGHT AND EARLY THURSDAY. +SN MAY OCCUR IN HEAVIER
BANDS...MOST LIKELY NEAR I-40 IN W OK. EXPECT RAPIDLY VARYING VSBY
AND CIG VALUES THRU THE NIGHT AND EARLY THURSDAY WHEREVER SN OR
RASN OCCUR. CONDITIONS WILL IMPROVE SLOWLY FROM ABOUT 15Z ONWARD
TOMORROW...AS CIGS/VSBYS IMPROVE FROM N TO S...ALTHOUGH
KHBR/KLAW/KSPS WILL LIKELY REMAIN MVFR OR IFR THRU AT LEAST 00Z
TOMORROW EVENING. KPNC SHOULD REMAIN VFR THRU THE ENTIRE EVENT.
PREV DISCUSSION... /ISSUED 311 PM CST WED JAN 21 2015/
DISCUSSION...
MAIN CONCERN IS TONIGHT/THURSDAY WINTER WEATHER EVENT.
MODELS HAVE CONT TO INDICATE AN EAST WEST BAND OF RAIN/SNOW
TRANSITIONING OVERNIGHT TO MAINLY SNOW NEAR THE I-40 CORRIDOR.
HAVE GONE AHEAD AN GONE WITH A WINTER STORM WARNING IN WESTERN OK
WHERE SOME AMOUNTS IN EXCESS OF 4 INCHES SEEM LIKELY. FARTHER EAST
HAVE INCREASED SNOW AMOUNTS BASED ON CONSISTENT NATURE OF ALL THE
MODELS.
THIS BAND SHOULD THEN TRANSLATE SOUTH AND GRADUALLY WEAKEN
THURSDAY MORNING... AND PROBABLY TRANSITION BACK TO RAIN AS
SURFACE TEMPS WARM.
STILL APPEARS THAT THE SNOW THAT OCCURS FURTHER EAST... IN CENTRAL
INTO SOUTHERN PARTS OF OKLAHOMA INTO NORTH TEXAS... MAY OCCUR AS A
BURST OF HEAVIER SNOW. THIS MAY INITIALLY ACCUMULATE WITH EVEN
SOME SLUSH ON AREA ROADWAYS... BUT THEN POSSIBLY MELT AS THE BAND
MOVES SOUTH AND WEAKENS LATE TONIGHT AND THURSDAY MORNING ALONG
WITH WARMING TEMPS. CONDITIONS SHOULD IMPROVE DRAMATICALLY BY AFTN
ACROSS NORTHERN 2/3RDS OF OKLAHOMA. CLOUD COVER AND CONT PRECIP
EXPECTED TO CONT NEAR THE RED RIVER INTO THURSDAY NIGHT. AGAIN
COULD SEE SOME SNOW MIXING BACK IN WITH THE RAIN THERE. NO
ADDITIONAL ACCUMULATIONS ARE EXPECTED BY THAT TIME.
AFTER THIS SYSTEM MOVES BY WE SEE A RATHER QUICK WARM UP INTO THE
WEEKEND AS NORTHWEST FLOW DEVELOPS... WHICH LOOKS TO BRING AIRMASS
OFF THE FRONT RANGE WHICH WILL HAVE WARMED FROM DOWNSLOPING
COMPRESSION. BY EARLY NEXT WEEK RIDGING ALOFT WILL KEEP THE WARM
DRY CONDITIONS GOING INTO THE LATTER PART OF THE MONTH.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 34 42 28 49 / 100 40 0 0
HOBART OK 32 37 24 46 / 100 50 10 0
WICHITA FALLS TX 35 39 30 49 / 100 70 30 10
GAGE OK 28 38 17 44 / 100 20 0 0
PONCA CITY OK 33 44 23 50 / 20 10 0 0
DURANT OK 36 43 33 49 / 100 90 30 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
THURSDAY FOR OKZ005-006-011-012-017>019-023>025-027>030-
035>040-044-045.
WINTER STORM WARNING UNTIL NOON CST THURSDAY FOR OKZ004-009-010-
014>016-021-022-033-034.
TX...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
THURSDAY FOR TXZ083>090.
&&
$$
17/23
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1229 PM CST TUE JAN 20 2015
.UPDATE...SURFACE FRONT CONTINUES TO MOVE SLOWLY ACROSS NW MIDDLE
TENNESSEE, WITH PASSAGE EVIDENT AT CKV, BUT NOT YET AT BNA.
SLIGHTLY COOLER AIR IS MOVING IN BEHIND THE FRONT, BUT DEW POINTS
AREN`T SEEMING TO BUDGE. AIR MASS CHANGE WILL INDEED BE SLOW. ONLY
HIGH CLOUDS ARE CURRENTLY FILLING IN BEHIND THE FRONT, SO NO
PRECIPITATION IS EXPECTED AT LEAST THROUGH THE AFTERNOON. HAVE
UPDATED THE GRIDS AND THE PUBLIC FORECAST TO INCREASE TODAY`S HIGH
TEMPERATURES BY A COUPLE OF DEGREES, SINCE WE HAD ALREADY HIT OUR
FORECAST HIGH HERE.
&&
.PREV DISCUSSION... /ISSUED 1147 AM CST TUE JAN 20 2015/
UPDATE...FOR 18Z AVIATION.
AVIATION...18Z TAF DISCUSSION.
AN APPROACHING SHORTWAVE WILL LEAD TO AN INCREASE IN CLOUD COVER
FOR ALL THREE MIDDLE TN TERMINALS. CLOUDS SHOULD STAY IN THE VFR
CATEGORY. MENTIONED VCSH AT CKV. HRRR DOES SHOW SHOWER ACTIVITY
CURRENTLY OVER SE KANSAS AND WESTERN MO HOLDING TOGETHER LONG
ENOUGH TO PRODUCE A LIGHT, BRIEF SHOWER AT THAT TERMINAL. BEHIND
THE SHORTWAVE SKIES SHOULD GO SKC RATHER QUICKLY AT CKV AND BNA.
MOISTURE MAY LINGER A LITTLE LONGER AT CSV. COLD FRONT CURRENTLY
LOCATED NEAR BNA WILL CONTINUE TO PUSH EAST. WINDS AT CKV HAVE
ALREADY VEERED TO THE NW. BNA AND CSV WILL FOLLOW IN THE NEXT FEW
HOURS. WINDS SHOULD STAY LIGHT AFTER THIS EVENING.
REAGAN
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1147 AM CST TUE JAN 20 2015
.UPDATE...FOR 18Z AVIATION.
&&
.AVIATION...18Z TAF DISCUSSION.
AN APPROACHING SHORTWAVE WILL LEAD TO AN INCREASE IN CLOUD COVER
FOR ALL THREE MIDDLE TN TERMINALS. CLOUDS SHOULD STAY IN THE VFR
CATEGORY. MENTIONED VCSH AT CKV. HRRR DOES SHOW SHOWER ACTIVITY
CURRENTLY OVER SE KANSAS AND WESTERN MO HOLDING TOGETHER LONG
ENOUGH TO PRODUCE A LIGHT, BRIEF SHOWER AT THAT TERMINAL. BEHIND
THE SHORTWAVE SKIES SHOULD GO SKC RATHER QUICKLY AT CKV AND BNA.
MOISTURE MAY LINGER A LITTLE LONGER AT CSV. COLD FRONT CURRENTLY
LOCATED NEAR BNA WILL CONTINUE TO PUSH EAST. WINDS AT CKV HAVE
ALREADY VEERED TO THE NW. BNA AND CSV WILL FOLLOW IN THE NEXT FEW HOURS. WINDS
SHOULD STAY LIGHT AFTER THIS EVENING.
REAGAN
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
540 PM CST WED JAN 21 2015
.AVIATION...
/00Z TAFS/
AREAS OF LIGHT TO MODERATE RAIN ARE OVERSPREADING NORTH TEXAS THIS
EVENING AND CONDITIONS ARE EXPECTED TO DETERIORATE THROUGH THE
OVERNIGHT HOURS. AS LIGHT RAIN CONTINUES TO FALL INTO DRIER AIR
NEAR THE SURFACE CIGS WILL CONTINUE TO LOWER. THIS SHOULD OCCUR
RATHER QUICKLY THIS EVENING SO WHILE THE MAJOR AIRPORTS WILL START
OUT WITH VFR CIGS...A RAPID LOWERING IS EXPECTED LATER THIS
EVENING. WINDS WILL INCREASE OUT OF THE NORTHEAST AS LOW PRESSURE
DEEPENS ACROSS DEEP SOUTH TEXAS.
THE MAIN CONCERNS FOR TONIGHT WILL BE CIGS AND PRECIPITATION TYPE.
AT THIS TIME...PRECIPITATION IS EXPECTED TO BE ALL RAIN THROUGH
THE OVERNIGHT HOURS. AS THE THERMAL PROFILE ALOFT COOLS WITH THE
APPROACH OF THE UPPER DISTURBANCE LATE TONIGHT INTO TOMORROW THERE
COULD BE SOME SNOW THAT MIXES WITH THE RAIN. HAVE INCLUDED A -RASN
AT AFW AND FTW WHERE THIS IS MOST LIKELY TO OCCUR. KEEP IN MIND
THOUGH THAT SURFACE TEMPERATURES ARE EXPECTED TO BE IN THE UPPER
30S AND THE ABOVE FREEZING AIR WILL EXTEND UPWARD TO ABOUT 2000FT.
SO WHILE THERE COULD BE SOME SNOW MIX IN...NO IMPACTS ARE EXPECTED
AS ANY SNOW WOULD MELT. IFR CIGS AND RAIN ARE EXPECTED TO
CONTINUE THROUGH THURSDAY.
DUNN
&&
.PREV DISCUSSION... /ISSUED 254 PM CST WED JAN 21 2015/
THIS PACKAGE LOOKS VERY SIMILAR TO THE LAST ONE. RAIN HAS ALREADY
STARTED NEAR COLEMAN AND THE PRECIP SHIELD CONTINUES TO MOVE
NORTHEAST TOWARDS NORTH/CENTRAL TX. WE EXPECT THE RAIN TO START
ALONG THE I-35 CORRIDOR BEFORE MIDNIGHT AND IN EASTERN ZONES BY
EARLY MORNING. CURRENT STORM TOTAL QPF RUNS FROM ABOUT AN INCH IN
NORTHWESTERN COUNTIES TO OVER TWO INCHES IN SOUTHEASTERN
COUNTIES.
WE CONTINUE TO FORECAST RAIN TO MIX WITH SNOW BY THURSDAY MORNING
IN NORTHWESTERN COUNTIES...BUT TEMPERATURES WILL REMAIN ABOVE
FREEZING AND ONLY GRASSY SURFACES ARE EXPECTED TO ACCUMULATE UP
TO A FEW TENTHS OF AN INCH. TEMPERATURES WILL CLIMB DURING THE
DAY TO AROUND 40 IN THOSE AREAS...AND A CHANGE BACK TO RAIN BY
AFTERNOON SHOULD MELT/WASH AWAY ANY SNOW THAT REMAINS FROM THE
MORNING.
ONE FACTOR THAT MAY IMPACT SNOW ACCUMULATIONS IS IF BANDING
PRECIPITATION SETS UP. THESE BANDS OF HEAVIER PRECIP TEND TO COOL
THE ATMOSPHERE AND THE RAIN/SNOW MIX MAY CHANGE TO ALL SNOW.
GUIDANCE IS NOT GOOD AT PREDICTING EXACTLY WHERE/WHEN THESE
MESOSCALE FEATURES WILL EXIST UNTIL THE EVENT GETS CLOSER...AND
THE HIGHER RESOLUTION SHORT TERM MODELS ARE A BIG HELP. CURRENTLY
THE HRRR RUNS THROUGH 09Z THURSDAY...AND IT IS NOT SHOWING ANY
STRONG BANDS YET.
THE HEAVIER PRECIPITATION SHOULD CONTINUE THROUGH THURSDAY
AFTERNOON...AND THEN BECOME GENERALLY LIGHTER WITH LESS AREAL
COVERAGE BY THURSDAY EVENING. AS THE ATMOSPHERE DRIES OUT
THURSDAY NIGHT INTO FRIDAY MORNING...PRECIPITATION WILL BECOME
MORE SCATTERED. ONCE AGAIN...FRIDAY MORNING WILL BRING COOLER
TEMPERATURES AND EXCEPT IN THE SOUTH AND SOUTHEAST...PRECIP THAT
DOES OCCUR WILL LIKELY BE A RAIN/SNOW MIX ONCE AGAIN. WE DO NOT
EXPECT ANY SNOW ACCUMULATIONS OTHER THAN A POSSIBLE TENTH OF AN
INCH OR SO ON GRASSY SURFACES IN WESTERN THROUGH NORTHERN
COUNTIES.
THE METROPLEX MAY SEE SNOW FLAKES MIXED WITH RAIN...BUT
TEMPERATURES SHOULD REMAIN IN THE MID 30S OR ABOVE AND THERE
SHOULD BE NO ACCUMULATIONS. AREAS SOUTHEAST OF A LINE FROM
LAMPASAS TO ATHENS WILL LIKELY SEE NO SNOW AT ALL. RAIN WILL
LIKELY END EARLY FRIDAY AFTERNOON IN EASTERN COUNTIES AS THE
SYSTEM CONTINUES TO MOVE OUT.
THE REST OF THE FORECAST IS DRY...AND AS SKIES CLEAR OUT FRIDAY
NIGHT...SATURDAY MORNING LOWS WILL HOVER AROUND FREEZING ACROSS
MUCH OF THE AREA. A WARM UP BEGINS ON SATURDAY WITH HIGHS IN THE
60S EXPECTED BY SUNDAY AND CONTINUING INTO WEDNESDAY. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 42 42 35 48 33 / 100 100 40 30 5
WACO, TX 44 44 37 49 31 / 100 100 50 30 10
PARIS, TX 41 43 36 48 31 / 100 100 50 30 5
DENTON, TX 40 42 35 48 30 / 100 100 40 20 5
MCKINNEY, TX 41 42 35 48 31 / 100 100 40 30 5
DALLAS, TX 42 43 35 49 34 / 100 100 40 30 5
TERRELL, TX 43 43 37 48 32 / 100 100 50 30 5
CORSICANA, TX 43 44 37 48 32 / 100 100 50 30 10
TEMPLE, TX 45 45 38 50 32 / 100 100 50 30 10
MINERAL WELLS, TX 40 42 34 49 30 / 100 100 40 20 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
248 PM CST TUE JAN 20 2015
.DISCUSSION...
AT 2 PM...SURFACE HIGH PRESSURE WAS LOCATED OVER THE NORTHERN GULF
COAST AND A WEAK COLD FRONT EXTENDED FROM PINE BLUFF TO JUST
SOUTH OF DFW TO MAF. MAIN ISSUE IN THE SHORT TERM IS SEA FOG
POTENTIAL...HOW FAR THE FOG WILL MOVE INLAND...TIMING THE ONSET
AND VISIBILITY RESTRICTIONS. WATER TEMPS ARE 50-51 AND SFC DEW PTS
ARE NEAR 60 SO CONDITIONS SEEM RIPE FOR DENSE SEA FOG TO DEVELOP.
THE HRRR DID A GREAT JOB TIMING THE ONSET AND AREA OF FOG
DEVELOPMENT LAST NIGHT SO WILL LEAN TOWARD THE HRRR SOLUTION
TONIGHT. ATTM...DENSE FOG SHOULD DEVELOP NEAR THE COAST BETWEEN
00-01Z AND GRADUALLY EXPAND INLAND. THE WEAK FRONT TO THE NORTH
WILL BE MOVING SOUTH AND WILL CROSS THE CWA BY 09Z. AM NOT SURE
HOW THIS FEATURE WILL AFFECT FOG POTENTIAL LATE TONIGHT. STRONGER
WINDS BEHIND THE BOUNDARY COULD PROVIDE ENOUGH MIXING TO LIFT THE
FOG INTO A LOW STRATUS. A DENSE FOG ADVISORY WILL LIKELY BE
REQUIRED LATER TONIGHT FOR COASTAL COUNTIES AND PROBABLY THE NEXT
TIER OF COUNTIES INLAND.
FCST SOUNDINGS SHOW SATURATION INCREASING ON WEDNESDAY AS
ISENTROPIC UPGLIDE BEGINS. PROBABLY GET SOME VERY LIGHT RAIN
DURING THE DAY...ESPECIALLY IN THE AFTERNOON AS SATURATION
DEEPENS. AN UPPER LEVEL TROUGH OVER CA WILL MOVE EAST ON WEDNESDAY
AND APPROACH THE 4 CORNERS REGION WED NIGHT. WINDS ALOFT WILL
BECOME SOUTHWEST AND A SERIES OF WEAK UPPER LEVEL DISTURBANCES
WILL BEGIN TO TRAVERSE SE TX. IN ADDITION...AN AREA OF LOW
PRESSURE WILL DEVELOP OVER DEEP SOUTH TEXAS AND THIS FEATURE WILL
HELP FOCUS LOW LEVEL CONVERGENCE ACROSS THE COASTAL PLAINS INTO SE
TX BY EARLY THURSDAY. SE TX WILL ALSO LIE IN A STRENGTHENING
120-140 KT RRQ WHICH WILL ALSO ASSIST LIFT. PW VALUES WILL
INCREASE WED NIGHT INTO THURSDAY REACHING 1.50 INCHES AROUND 18Z
THURSDAY. THIS IS 2 STD DEV ABOVE NORMAL FOR THIS TIME OF YEAR.
FCST SOUNDINGS SHOW A SKINNY SATURATED PROFILE FROM THE SFC TO 300
MB SO RAINFALL COULD GET BRIEFLY HEAVY THURSDAY MORNING INTO THE
EARLY AFTN. RAIN SHOULD DIMINISH QUICKLY THURSDAY NIGHT AS THE
COASTAL LOW EXITS THE REGION. THAT SAID...STRONG JET DYNAMICS AND
LIFT ON THE EAST SIDE OF THE TROUGH AXIS SHOULD KEEP PERIODS OF
VERY LIGHT RAIN OR DRIZZLE GOING THROUGH MUCH OF FRIDAY.
UPPER FLOW BECOMES CONFLUENT FRIDAY NIGHT AND MSTR LEVELS BEGIN TO
DROP SO ANY REMAINING LT RAIN WILL COME TO AN END. CLEARING SKIES
ARE EXPECTED FRIDAY NIGHT WITH ONLY PERIODS OF CIRRUS CLOUDS
EXPECTED THROUGH THE WEEKEND. AN EXPANDING UPPER LEVEL RIDGE OVER
CA WILL CREATE A NW FLOW OVER TEXAS KEEPING THINGS DRY AND
SEASONAL FOR MUCH OF NEXT WEEK. THE UPPER FLOW WILL BEGIN TO
FLATTEN TOWARD THE END OF NEXT WEEK AS ANOTHER STORM SYSTEM
APPROACHES THE DESERT SOUTHWEST. 43
&&
.MARINE...
MOIST AND WARM AIR OVER COOLER SHALLOW SHELF WATERS INCREASING THE
PROBABILITY OF RETURN SEA FOG THIS EVENING...QUICKLY BECOMING DENSE
THROUGH MIDNIGHT AND PERSISTING THROUGH A GOOD MAJORITY OF WEDNESDAY
MORNING. IF FOG DOES FORM...VISIBILITIES WILL FALL TO A MILE OR
UNDER THUS PROMPTING AN OVERNIGHT MARINE DENSE FOG ADVISORY. AN
EMERGING WESTERN STORM SYSTEM WILL ORIENT THE LATE WEEK PRESSURE
GRADIENT FROM NORTHEAST TO SOUTHWEST...ULTIMATELY GENERATING A
MODERATE TO STRONG NORTHEASTERLY FETCH THURSDAY...BACKING MORE
NORTHERLY WITH A COLD FRONTAL PASSAGE FRIDAY. THIS FETCH WILL
PRODUCE HIGHER COASTAL WATER LEVELS/TIDES AND CHURN THE OPEN SEAS TO
GREATER THAN 6 FEET NEARSHORE...10 FEET OFFSHORE THURSDAY
NIGHT/EARLY FRIDAY MORNING. OFFSHORE WIND GUSTS TO GALE ARE ALSO
LIKELY DURING THIS THURSDAY-FRIDAY PERIOD OF HIGH WIND...SEAS AND
RAIN. MUCH IMPROVED WEEKEND WEATHER WITH A WEAKENING NORTHWEST TO
WEST WIND UNDER SLIGHTLY WARMER CONDITIONS. 31
&&
.CLIMATE...
HOUSTON REACHED 70 DEGREES AGAIN TODAY. THIS IS THE THIRD
CONSECUTIVE DAY WITH TEMPS AT OR ABOVE 70 DEGREES. THE LAST TIME
HOUSTON RECORDED 3 CONSECUTIVE DAYS WITH TEMPS AT OR ABOVE 70
DEGREES WAS BACK ON DEC 11...DEC 12 AND DEC 13. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 51 64 50 51 40 / 10 20 80 100 40
HOUSTON (IAH) 53 66 54 55 42 / 10 20 60 100 60
GALVESTON (GLS) 54 63 57 58 45 / 10 20 50 100 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1204 PM CST TUE JAN 20 2015
.AVIATION...
THE LAST REMNANTS OF THIS MORNING`S DENSE FOG NOW WHISKING AWAY
AT THE TOP OF THE 18Z HOUR. VFR/SKC WITH A VARIABLE BREEZE THIS
AFTERNOON. AN APPROACHING WEAK NORTHERN BOUNDARY WILL SLOWLY
TRAVEL ACROSS THE REGION EARLY WEDNESDAY...VEERING LOW LEVEL WINDS
TO THE NORTH-NORTHEAST. INTERIOR AND SEA FOG IS FORECAST TO RETURN
WITH THE HIGHER RESOLUTION MODELING BRINGING THE ONSET OF MVFR (OR
LOWER) CATEGORY FOG INTO THE SOUTHERN 1/2 OF REGION JUST AFTER
00Z TONIGHT. AN EARLIER ONSET THAN TODAY WITH A GOOD CHANCE FOR
SIMILAR VISIBILITY RESTRICTIONS WITHIN FOG. THE NORTHERN BOUNDARY
MAY INCREASE NNE FLOW ENOUGH TO LIMIT THE EXTENT OF (L)IFR FOG
DEVELOPMENT ACROSS TERMINALS FROM KIAH NORTHWARD. A TRADITIONALLY
COOLER AND MORE MOIST FLOW DURING THE WINTER MONTHS...AN ESTABLISHED
NORTHEASTERLY WIND SHOULD KEEP MVFR OVERCAST IN PLACE THROUGH THE
WEDNESDAY PM HOURS. 31
&&
.PREV DISCUSSION... /ISSUED 1008 AM CST TUE JAN 20 2015/
UPDATE...
EXTENDED DENSE FOG ADVISORY FOR GALVESTON...CHAMBERS AND LIBERTY
COUNTY THROUGH 18Z. SEE MORNING UPDATE.
DISCUSSION...
FOG IS ERODING RATHER QUICKLY OVER MUCH OF SE TX BUT AREAS OF FOG
CONTINUE TO LINGER IN THE GALVESTON BAY REGION. GHAVE EXTENDED THE
DENSE FOG ADVISORY FOR COUNTIES SURROUNDING THE BAY (EXCLUDING
HARRIS) THROUGH 18Z. HRRR IS HINTING AT DENSE FOG REDEVELOPING
SHORTLY AFTER SUNSET NEAR THE COAST AND EXPANDING INLAND
OVERNIGHT. HAVE ADDED FOG TO THE WEATHER GRIDS FOR TONIGHT. REST
OF THE FCST LOOKS OK. NEW ZONES/NPW OUT SHORTLY. 43
&&
PREV DISCUSSION... /ISSUED 532 AM CST TUE JAN 20 2015/
AVIATION...
DEALING WITH IFR/LIFR CEILINGS AND VISIBILITIES EARLY THIS MORNING
AT ALMOST ALL AREA TAF SITES. EXPECT IMPROVEMENT AROUND MID MORNING
WITH VFR CONDITIONS THROUGHOUT THE AFTERNOON HOURS. COULD SEE ANOTHER
ROUND OF IFR/LIFR CONDITIONS AGAIN TONIGHT INTO WEDNESDAY MORNING AHEAD
OF THE NEXT COLD FRONT. DETERIORATING CEILINGS AND VISIBILITIES INTO
WEDNESDAY NIGHT AND THURSDAY WITH WIDESPREAD R- ASSOCIATED WITH THE
NEXT STORM SYSTEM. 42
&&
PREV DISCUSSION... /ISSUED 354 AM CST TUE JAN 20 2015/
DISCUSSION...
WIDESPREAD FOG IS ONGOING ACROSS SOUTHEAST TEXAS THIS MORNING AS
LIGHT WINDS AND CLEAR SKIES ALLOWED FOR GOOD COOLING WHILE
MOISTURE CONTINUES TO MOVE NORTHWARD INTO THE REGION. DENSE FOG
HAS BEEN MORE PERSISTENT ALONG THE AXIS OF BEST LOW LEVEL MOISTURE
ACROSS OUR WESTERN AND SOUTHWESTERN COUNTIES. VISIBILITIES FURTHER
EAST HAVE DROPPED TO 1/4 MILE OR LESS AT TIMES AND THUS WILL
LEAVE THE CURRENT DENSE FOG ADVISORY IN PLACE FOR ALL OF SOUTHEAST
TEXAS. EXPECT CONDITIONS TO IMPROVE QUICKLY AROUND MID MORNING
WITH ANOTHER RELATIVELY WARM DAY ACROSS SOUTHEAST TEXAS.
ONLY SIGNIFICANT CHANGE TO THE FORECAST THIS MORNING IS TO HOLD
POPS INTO FRIDAY ACROSS MUCH OF THE REGION. A WEAK COLD FRONT
WILL MOVE INTO THE REGION OVERNIGHT BRINGING CLOUDS AND SLIGHTLY
COOLER TEMPERATURES FOR WEDNESDAY. RAIN CHANCES RAMP UP QUICKLY
LATE WEDNESDAY NIGHT AS AN UPPER LEVEL TROUGH DEEPENS ACROSS THE
WESTERN UNITED STATES. AS THIS SYSTEM APPROACHES A COASTAL TROUGH
WILL DEVELOP ON THURSDAY NEAR THE COASTAL BEND REGION WHILE
PERSISTENT ISENTROPIC UPGLIDE COMBINED WITH A FAVORABLE JET
POSITION WILL SUPPORT WIDESPREAD RAINFALL ACROSS SOUTHEAST TEXAS
THURSDAY. RAINFALL AMOUNTS WILL AVERAGE BETWEEN 1-2 INCHES ALTHOUGH
SOME ISOLATED 3+ INCH TOTALS ARE POSSIBLE. THE BULK OF THE
PRECIPITATION WILL EXIT TO THE EAST THURSDAY NIGHT BUT MODELS
CONTINUE TO SLOW THE PROGRESSION OF THE UPPER TROUGH...AND THUS
WILL HOLD ONTO POPS A BIT FURTHER INTO FRIDAY. SKIES WILL CLEAR
OVER THE WEEKEND AS ANOTHER UPPER TROUGH DIGS INTO THE
SOUTHEASTERN UNITED STATES. THIS WILL ALLOW FOR PERSISTENT
NORTHWEST FLOW ALOFT AND DRY AND SEASONABLE CONDITIONS THROUGH
THE MIDDLE OF NEXT WEEK. 38
&&
MARINE...
LIGHT MAINLY SOUTH WINDS WILL PERSIST THROUGH TUESDAY NIGHT.
SOME PATCHY SEA FOG IS POSSIBLE AS WARMER AND MORE MOIST AIR
OVERRIDES THE COOLER SHELF WATERS. EAST TO NORTHEAST WINDS
RETURN TO THE AREA WEDNESDAY AND STRENGTHEN THROUGH FRIDAY
MORNING AHEAD OF AN APPROACHING STORM SYSTEM. THIS SYSTEM
WILL BRING STRONG WINDS (GUSTS POSSIBLY REACHING GALE FORCE
LATE THURSDAY AFTERNOON THROUGH EARLY FRIDAY MORNING)...ROUGH
SEAS...RAIN...AND TIDE LEVELS ABOVE TO MUCH ABOVE NORMAL.
SMALL CRAFT ADVISORIES WILL BE NEEDED. WINDS WILL BECOME MORE
NORTHERLY AS THE DAY PROGRESSES ON FRIDAY WITH THE STORM
SYSTEM EDGING OFF TO THE EAST. LIGHTER NORTH TO NORTHWEST
WINDS WILL PREVAIL OVER THE WEEKEND. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 49 64 49 49 / 0 0 20 80 100
HOUSTON (IAH) 72 50 66 52 56 / 0 10 20 50 90
GALVESTON (GLS) 67 56 63 54 60 / 0 10 20 50 90
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
CHAMBERS...GALVESTON...LIBERTY.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20
NM.
&&
$$
DISCUSSION...31
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1008 AM CST TUE JAN 20 2015
.UPDATE...
EXTENDED DENSE FOG ADVISORY FOR GALVESTON...CHAMBERS AND LIBERTY
COUNTY THROUGH 18Z. SEE MORNING UPDATE.
&&
.DISCUSSION...
FOG IS ERODING RATHER QUICKLY OVER MUCH OF SE TX BUT AREAS OF FOG
CONTINUE TO LINGER IN THE GALVESTON BAY REGION. GHAVE EXTENDED THE
DENSE FOG ADVISORY FOR COUNTIES SURROUNDING THE BAY (EXCLUDING
HARRIS) THROUGH 18Z. HRRR IS HINTING AT DENSE FOG REDEVELOPING
SHORTLY AFTER SUNSET NEAR THE COAST AND EXPANDING INLAND
OVERNIGHT. HAVE ADDED FOG TO THE WEATHER GRIDS FOR TONIGHT. REST
OF THE FCST LOOKS OK. NEW ZONES/NPW OUT SHORTLY. 43
&&
.PREV DISCUSSION... /ISSUED 532 AM CST TUE JAN 20 2015/
AVIATION...
DEALING WITH IFR/LIFR CEILINGS AND VISIBILITIES EARLY THIS MORNING
AT ALMOST ALL AREA TAF SITES. EXPECT IMPROVEMENT AROUND MID MORNING
WITH VFR CONDITIONS THROUGHOUT THE AFTERNOON HOURS. COULD SEE ANOTHER
ROUND OF IFR/LIFR CONDITIONS AGAIN TONIGHT INTO WEDNESDAY MORNING AHEAD
OF THE NEXT COLD FRONT. DETERIORATING CEILINGS AND VISIBILITIES INTO
WEDNESDAY NIGHT AND THURSDAY WITH WIDESPREAD R- ASSOCIATED WITH THE
NEXT STORM SYSTEM. 42
PREV DISCUSSION... /ISSUED 354 AM CST TUE JAN 20 2015/
DISCUSSION...
WIDESPREAD FOG IS ONGOING ACROSS SOUTHEAST TEXAS THIS MORNING AS
LIGHT WINDS AND CLEAR SKIES ALLOWED FOR GOOD COOLING WHILE
MOISTURE CONTINUES TO MOVE NORTHWARD INTO THE REGION. DENSE FOG
HAS BEEN MORE PERSISTENT ALONG THE AXIS OF BEST LOW LEVEL MOISTURE
ACROSS OUR WESTERN AND SOUTHWESTERN COUNTIES. VISIBILITIES FURTHER
EAST HAVE DROPPED TO 1/4 MILE OR LESS AT TIMES AND THUS WILL
LEAVE THE CURRENT DENSE FOG ADVISORY IN PLACE FOR ALL OF SOUTHEAST
TEXAS. EXPECT CONDITIONS TO IMPROVE QUICKLY AROUND MID MORNING
WITH ANOTHER RELATIVELY WARM DAY ACROSS SOUTHEAST TEXAS.
ONLY SIGNIFICANT CHANGE TO THE FORECAST THIS MORNING IS TO HOLD
POPS INTO FRIDAY ACROSS MUCH OF THE REGION. A WEAK COLD FRONT
WILL MOVE INTO THE REGION OVERNIGHT BRINGING CLOUDS AND SLIGHTLY
COOLER TEMPERATURES FOR WEDNESDAY. RAIN CHANCES RAMP UP QUICKLY
LATE WEDNESDAY NIGHT AS AN UPPER LEVEL TROUGH DEEPENS ACROSS THE
WESTERN UNITED STATES. AS THIS SYSTEM APPROACHES A COASTAL TROUGH
WILL DEVELOP ON THURSDAY NEAR THE COASTAL BEND REGION WHILE
PERSISTENT ISENTROPIC UPGLIDE COMBINED WITH A FAVORABLE JET
POSITION WILL SUPPORT WIDESPREAD RAINFALL ACROSS SOUTHEAST TEXAS
THURSDAY. RAINFALL AMOUNTS WILL AVERAGE BETWEEN 1-2 INCHES ALTHOUGH
SOME ISOLATED 3+ INCH TOTALS ARE POSSIBLE. THE BULK OF THE
PRECIPITATION WILL EXIT TO THE EAST THURSDAY NIGHT BUT MODELS
CONTINUE TO SLOW THE PROGRESSION OF THE UPPER TROUGH...AND THUS
WILL HOLD ONTO POPS A BIT FURTHER INTO FRIDAY. SKIES WILL CLEAR
OVER THE WEEKEND AS ANOTHER UPPER TROUGH DIGS INTO THE
SOUTHEASTERN UNITED STATES. THIS WILL ALLOW FOR PERSISTENT
NORTHWEST FLOW ALOFT AND DRY AND SEASONABLE CONDITIONS THROUGH
THE MIDDLE OF NEXT WEEK. 38
MARINE...
LIGHT MAINLY SOUTH WINDS WILL PERSIST THROUGH TUESDAY NIGHT.
SOME PATCHY SEA FOG IS POSSIBLE AS WARMER AND MORE MOIST AIR
OVERRIDES THE COOLER SHELF WATERS. EAST TO NORTHEAST WINDS
RETURN TO THE AREA WEDNESDAY AND STRENGTHEN THROUGH FRIDAY
MORNING AHEAD OF AN APPROACHING STORM SYSTEM. THIS SYSTEM
WILL BRING STRONG WINDS (GUSTS POSSIBLY REACHING GALE FORCE
LATE THURSDAY AFTERNOON THROUGH EARLY FRIDAY MORNING)...ROUGH
SEAS...RAIN...AND TIDE LEVELS ABOVE TO MUCH ABOVE NORMAL.
SMALL CRAFT ADVISORIES WILL BE NEEDED. WINDS WILL BECOME MORE
NORTHERLY AS THE DAY PROGRESSES ON FRIDAY WITH THE STORM
SYSTEM EDGING OFF TO THE EAST. LIGHTER NORTH TO NORTHWEST
WINDS WILL PREVAIL OVER THE WEEKEND. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 49 64 49 49 / 0 0 20 80 100
HOUSTON (IAH) 72 50 66 52 56 / 0 10 20 50 90
GALVESTON (GLS) 67 56 63 54 60 / 0 10 20 50 90
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
CHAMBERS...GALVESTON...LIBERTY.
GM...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM.
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20
NM.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
925 PM EST WED JAN 21 2015
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL PASS JUST NORTH OF OUR AREA
TONIGHT. AN AREA OF LOW PRESSURE IS EXPECTED TO PROGRESS NORTHEAST
AND STRENGTHEN ALONG THE GULF COAST FRIDAY...PUSHING UP THE NORTH
CAROLINA COAST EARLY SATURDAY...BRINGING WINTRY WEATHER TO AT
LEAST THE MOUNTAINS.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 920 PM EST WEDNESDAY...
A FEW SHORTWAVES SWING BY AND WITH NW FLOW THERE WILL BE
SCATTERED SNOW SHOWERS/FLURRIES. STILL NOTHING MORE THAN AN INCH
OR LESS IN THE MTNS OF WRN GREENBRIER COUNTY AND WESTERN BATH.
MOST OF THE PRECIPITATION ASSOCIATED WITH A SHORT WAVE CROSSING
OUT OF OHIO WILL STAY NORTH OF THE FORECAST AREA. MODELS DO NOT
BRING LOWER CLOUDS INTO THE MOUNTAINS UNTIL AROUND 1AM/06Z. HAVE
REMOVED CHANCE OF PRECIPITATION IN THE WEST UNTIL THAT TIME.
STRONG HIGH PRESSURE WILL STRETCH FROM THE CENTRAL ROCKIES EAST
ACROSS THE PLAINS INTO THE OHIO VALLEY THURSDAY...WITH CONFLUENT
FLOW ALOFT. CLOUDS WILL BE MINIMAL OUTSIDE THE MOUNTAINS UNTIL
THURSDAY AFTERNOON WITH THE GULF LOW STARTING TO TAKE SHAPE. THERE
COULD BE SOME CLOUDS IN THE HIGH LEVELS THANKS TO THE CONFLUENT FLOW
FORMING ACROSS THE BLUE RIDGE AND EAST. OVERALL...THINK WILL SEE A
MOSTLY SUNNY MORNING TO BECOME PARTLY SUNNY BY AFTERNOON...WITH
STILL SOME STRATOCU LINGERING IN THE UPSLOPE AREAS.
LOWS TONIGHT ARE GOING TO RANGE FROM THE MID 20S ALLEGHANY
HIGHLANDS/GREENBRIER VALLEY...AND HIGHER ELEVATIONS OF THE NC
MTNS/GRAYSON...TO AROUND 30 NEW RIVER VALLEY AND PIEDMONT...WITH
LOWER TO MID 30S ALONG THE FOOTHILLS/ROANOKE...WITH SOME MIXING.
8H TEMPS WILL BE COOLER...SO OVERALL LOOKING AT HIGHS THURSDAY IN
THE MOUNTAINS ABOUT 5 TO 10 DEGREES COOLER THAN TODAY...WHILE THE
PIEDMONT THANKS TO DOWNSLOPE AND MORE SUN REMAIN MILD FOR LATE
JANUARY. HIGHS RANGING FROM THE UPPER 30S/LOWER 40S WEST TO LOWER
50S IN THE NC FOOTHILLS/PIEDMONT INTO SOUTHSIDE VA.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 215 PM EST WEDNESDAY...
COMPLEX SCENARIO IS AT HAND FOR THIS PORTION OF THE FORECAST. FOR
THE PAST SEVERAL DAYS...MODEL GUIDANCE HAS BEEN OFFERING A COASTAL
SYSTEM THAT PROGRESSIVELY HAS BECOME ONE WITH A GREATER IMPACT ON
OUR REGION IN TERMS OF THE POTENTIAL FOR WINTRY WEATHER. THE SAME
HOLDS TRUE TODAY WITH THE LATEST 12Z/7AM GUIDANCE.
THE VARIOUS GUIDANCE SOLUTIONS ARE NOT TOO DIFFERENT FROM EACH OTHER
IN TERMS OF ARRIVAL AND DEPARTURE...PERHAPS VARYING BY 3 TO 6 HOURS
FOR THE ONSET AND AROUND 6 HOURS FOR THE DEPARTURE. WE ARE STILL
OFFERING A FORECAST THAT BRINGS LIGHT PRECIPITATION INTO THE FAR
SOUTHWEST PORTION OF THE FORECAST AREA LATE THURSDAY
NIGHT...SPREADING NORTH DURING THE DAY FRIDAY...AND HAS THE BULK OF
THE NON-UPSLOPE PRECIPITATION EXITING BY MID-DAY SATURDAY. LINGERING
UPSLOPE SNOW SHOWERS ACROSS SOUTHEAST WEST VIRGINIA ARE FORECAST BY
ALL THE GUIDANCE SATURDAY AFTERNOON THROUGH SATURDAY NIGHT.
BETWEEN EARLY FRIDAY MORNING AND EARLY SATURDAY THE PRECIPITATION
TYPE HAS BEEN A FORECAST CHALLENGE...ALONG WITH THE SUBSEQUENT
MEASURABLE WINTRY PRECIPITATION. THE NAM CONTINUES TO BE AN OUTLIER
WITH A VERY PROGRESSIVE 85H JET SCREAMING INTO THE REGION FRIDAY
AFTERNOON AND EARLY EVENING WITH MODERATING 85H TEMPS AS HIGH AS +8
C OVER DANVILLE VA BY MIDNIGHT FRIDAY NIGHT WITH THE 0C 85H TEMP AS
FAR NORTHWEST AS THE WV/VA BORDER. THE GFS/ECWMF/CMC ALL HAVE A LESS
AGGRESSIVE 85H JET...AND THUS...LESS OF A SURGE OF WARM AIR
ADVECTION AT THAT AND OTHER LOWER LEVELS. THIS KEEPS MORE OF THE
AREA AT OR BELOW 0C AT 85H. THE VISUAL CONSENSUS BETWEEN THE
GFS/ECMWF/CMC WOULD BE THE GFS AS THE ECMWF IS A LITTLE MILDER AND
THE CMC IS COLDER. THE P-TYPE IN THE FORECAST WILL REFLECT A TOP
DOWN APPROACH THAT MAKES USE OF THE GFS T/TD PROFILE. QPF AMOUNTS
WILL REFLECT THAT OFFERED BY WPC WITH SOME ADJUSTMENTS UPWARD ALONG
THE SOUTHERN BLUE RIDGE TO ACCOUNT FOR THE AFFECTS OF UPSLOPE
TRAJECTORIES FRIDAY EVENING. PROBABILITY OF PRECIPITATION WILL REFLECT
CLOSELY TO THAT OFFERED BY PRECIPITATION FIELDS AND TIMING OF THE
GFS.
WITH ALL THIS IN MIND...THE BIGGEST ADJUSTMENT TO OUR FORECAST WILL
BE A GREATER INCLUSION OF SLEET IN THE FORECAST...ESPECIALLY ACROSS
THE SOUTHWESTERN PORTIONS OF THE AREA ON FRIDAY...AND AREAS ALONG
AND NEAR THE ROUTE 460 CORRIDOR FRIDAY NIGHT. THE FORECAST WILL ALSO
REFLECT MORE WHITE RAIN SNOW DURING THE DAY FRIDAY IN THE WEST.
GIVEN HOW MILD OUR TEMPERATURES HAVE BEEN AS OF LATE...CONFIDENCE IS
LOW THAT SNOW OR SLEET WILL ACCUMULATE TO ANY SUBSTANTIAL DEGREE ON
FRIDAY. PLAIN RAIN WILL BE FORECAST ON FRIDAY FOR AREAS EAST OF THE
BLUE RIDGE.
FRIDAY NIGHT INTO EARLY SATURDAY MORNING WILL BE THE TIME PERIOD OF
FOCUS FOR MEASURABLE WINTRY PRECIPITATION. ACROSS THE
MOUNTAINS...AND THE PIEDMONT ALONG AND NORTH OF ROUGHLY ROUTE 460
LOOKS TO BE A SNOW/SLEET MIXTURE. THE FARTHER NORTH IN THIS AREA THE
BETTER CHANCE FOR PURE SNOW. CLOSER TO SOUTHSIDE VIRGINIA AND
ADJOINING PORTIONS OF NORTH CENTRAL NORTH CAROLINA WILL MORE LIKELY
SEEN A PLAIN COLD RAIN.
FORECAST SNOWFALL AMOUNTS FOR THIS PACKAGE WILL BE GREATEST ALONG
AND NORTH OF INTERSTATE 64 IN SOUTHEAST WEST VIRGINIA AND SOUTHWEST
VIRGINIA WITH TWO TO FOUR INCHES BEING COMMON. FOR THE HIGHER
ELEVATIONS OF WESTERN PARTS OF GREENBRIER COUNTY EXPECT AMOUNTS IN
THE FOUR TO SIX INCH RANGE. ELSEWHERE ACROSS THE MOUNTAINS...LESS
THAN ONE TO TWO INCHES WILL BE MORE PROBABLE. AREAS OF THE PIEDMONT
NORTH OF ROUGHLY THE ROANOKE RIVER WILL BE GENERALLY LESS THAN AN
INCH. IF THIS FORECAST HOLDS THROUGH THE NEXT OR NEXT COUPLE OF
FORECAST SHIFTS...WINTER WEATHER HEADLINES WOULD BE NEEDED FOR AN
AREA ROUGHLY ALONG AND NORTH OF A LINE FROM HINTON WV TO LEXINGTON
OR AMHERST VA. WILL CONTINUE TO HIGHLIGHT THE THREAT IN THE
HAZARDOUS WEATHER OUTLOOK.
SATURDAY AFTERNOON INTO SATURDAY NIGHT THE AXIS OF THE PARENT UPPER
TROUGH CROSSES THE REGION AND WINDS SHIFT ABRUPTLY NORTHWEST AND
START TO INCREASE. 85H LEVEL WINDS A PROGGED TO BE IN THE 40-45 KT
RANGE FROM ROUGHLY NOON TO MIDNIGHT. THIS WILL ACTIVATE THE UPSLOPE
SNOW MACHINE AND PRODUCE ISOLATED TO SCATTERED SNOW SHOWERS FROM
SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH
CAROLINA. ADDITIONAL LIGHT ACCUMULATES OF SNOW WILL BE POSSIBLE
ALONG THE PREFERRED WESTERN SLOPES. ASSOCIATED FLURRIES MAY CARRY
DOWNSTREAM TO THE CREST OF THE BLUE RIDGE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 200 PM EST WEDNESDAY...
COASTAL LOW OFF THE NEW ENGLAND COAST SUNDAY MORNING WILL CONTINUE
TO PUSH EAST INTO THE ATLANTIC OCEAN DEPARTING INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK. UPSLOPE SNOW SHOWERS WILL CONTINUE IN THE
WAKE OF THE COASTAL SYSTEM. A FAST MOVING ALBERTA CLIPPER WILL DROP
SOUTHEAST AND WILL BRING MORE SNOW AND COLDER TEMPERATURES TO THE
REGION.
850MB TEMPERATURES LOOK COLD ENOUGH TO HAVE MOST PRECIPITATION IN
THE FORM OF SNOW WITH THIS CLIPPER. THE PROJECT PATH OF THE STORM
WITH THE BEST DYNAMIC AND MOISTURE IS JUST NORTH OF THE REGION. THE
HEAVIEST SNOW SHOULD FALL ACROSS NORTHERN WEST VIRGINIA...NORTHERN
VIRGINIA AND MARYLAND REGION...CLOSER TO THE MASON-DIXON LINE. FOR
OUR AREA...ADDITIONAL ACCUMULATING SNOW WILL CONTINUE ESPECIALLY IN
THE NORTHWEST MOUNTAINS WITH POTENTIAL FOR SNOW OUT TOWARD THE BLUE
RIDGE. ADVISORY LEVEL SNOWS MAY BE POSSIBLE ALONG THE WESTERN SLOPES
ESPECIALLY SUNDAY NIGHT INTO MONDAY. A LEE LOW REFORMATION IS
EXPECTED ALONG OR OFF THE EAST COAST MONDAY AND THIS SYSTEM
TRACKS NORTHEAST INTO TUESDAY.
THE UPPER TROUGH PERSISTS ALONG THE EAST COAST INTO MIDWEEK. SEVERAL
ADDITIONAL NORTHWEST FLOW DISTURBANCES OR ALBERTA CLIPPERS ARE
SLATED TO IMPACT THE REGION THROUGHOUT THE WEEK KEEPING THE THREAT
FOR WINTER PRECIPITATION HIGH. IT CERTAINLY APPEARS MORE WINTRY THAN
THIS PAST WEEK HAS BEEN. WITH A NEARLY FULL LATITUDE EAST COAST
UPPER TROF ANTICIPATED...TEMPERATURES WILL REMAIN BELOW NORMAL
DURING THE EXTENDED PERIOD.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AS OF 643 PM EST WEDNESDAY...
AN UPPER LEVEL DISTURBANCE WILL PASS TO OUR NORTH TONIGHT.
THIS SHOULD RESULT IN SOME LOWER CIGS FOR LWB/BLF OVERNIGHT.
CIGS AT BLF COULD LOWER TO SUB 1KFT BY 10Z...THEN RISE ABOVE TO
MVFR AFTER 15Z. MVFR SCT TO BKN CLOUDS ARE POSSIBLE AT LWB AND
BCB THURSDAY MORNING. OTHERWISE...VFR CONDITIONS WILL PREVAIL.
OUTSIDE OF THE TAF SITES...IN THE WESTERN UPSLOPE FAVORED
LOCATIONS ESPECIALLY SOUTHEAST WEST VIRGINIA A FEW SNOW FLURRIES
ARE POSSIBLE. THIS IS SUPPORTED BY HRRR AND RNK WRFARW.
HIGH PRESSURE WILL MOVE SOUTH OF THE GREAT LAKES ON THURSDAY
AFTERNOON...PASSING ACROSS NEW ENGLAND AND OFF SHORE THURSDAY
NIGHT...RETURNING THE MOUNTAINS TO VFR. MEANWHILE...A DEEP LOW
PRESSURE SYSTEM WILL DEVELOP ALONG THE GULF COAST THURSDAY
NIGHT...RADIATING MOISTURE NORTHWARD ALONG THE APPALACHIAN CHAIN.
MEDIUM TO HIGH CONFIDENCE OF CEILINGS...VISIBILITIES AND WINDS
DURING THE TAF PERIOD.
MODEL TRENDS ARE KEEPING OUR AREA WITH EITHER RAIN MAINLY EAST OF
THE BLUE RIDGE...AND WINTRY WEATHER TO RAIN BACK TO WINTRY WEATHER
IN THE MOUNTAINS. CONFIDENCE IS HIGH THAT THE ENTIRE REGION WILL
SEE SUB VFR CONDITIONS WITH THIS SYSTEM...QUESTION BEING PTYPE.
AVIATION INTERESTS SHOULD CONTINUE TO MONITOR LATER FORECASTS BUT
THE OUTLOOK FOR FRI-SAT DOES NOT LOOK GOOD FOR FLYING ALONG AND
EAST OF THE APPALACHIANS. AS THE STORM STRENGTHENS INTO SATURDAY
GUSTY NW WINDS WILL ENSUE LEADING TO SVR TURBULENCE IN THE
MOUNTAINS AND MID ATLANTIC NWD.
BY SUNDAY WILL SEE IMPROVING CONDITIONS EAST OF THE
MOUNTAINS...WITH LINGERING UPSLOPE CLOUDS AND POSSIBLE SUB VFR
CIGS AT BLF/LWB....WHICH COULD CONTINUE TO MONDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF/WP
NEAR TERM...AMS/WP
SHORT TERM...DS
LONG TERM...KK
AVIATION...KK/NF/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
643 PM EST WED JAN 21 2015
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL JUST NORTH OF OUR AREA TONIGHT.
AN AREA OF LOW PRESSURE IS EXPECTED TO PROGRESS NORTHEAST AND
STRENGTHEN ALONG THE GULF COAST FRIDAY...PUSHING UP THE NORTH
CAROLINA COAST EARLY SATURDAY...BRING WINTRY WEATHER TO AT LEAST
THE MOUNTAINS.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 240 PM EST WEDNESDAY...
BULK OF THE AREA WILL HAVE QUIET WX THROUGH THURSDAY. IN THE
NORTHWEST...A FEW SHORTWAVES SWING BY AND WITH NW FLOW THERE WILL BE
SCATTERED SNOW SHOWERS/FLURRIES. STILL NOTHING MORE THAN AN INCH OR
LESS IN THE MTNS OF WRN GREENBRIER COUNTY AND WESTERN BATH.
STRONG HIGH PRESSURE WILL STRETCH FROM THE CENTRAL ROCKIES EAST
ACROSS THE PLAINS INTO THE OHIO VALLEY THURSDAY...WITH CONFLUENT
FLOW ALOFT. CLOUDS WILL BE MINIMAL OUTSIDE THE MOUNTAINS UNTIL
THURSDAY AFTERNOON WITH THE GULF LOW STARTING TO TAKE SHAPE. THERE
COULD BE SOME CLOUDS IN THE HIGH LEVELS THANKS TO THE CONFLUENT FLOW
FORMING ACROSS THE BLUE RIDGE AND EAST. OVERALL...THINK WILL SEE A
MOSTLY SUNNY MORNING TO BECOME PARTLY SUNNY BY AFTERNOON...WITH
STILL SOME STRATOCU LINGERING IN THE UPSLOPE AREAS.
LOWS TONIGHT ARE GOING TO RANGE FROM THE MID 20S ALLEGHANY
HIGHLANDS/GREENBRIER VALLEY...AND HIGHER ELEVATIONS OF THE NC
MTNS/GRAYSON...TO AROUND 30 NEW RIVER VALLEY AND PIEDMONT...WITH
LOWER TO MID 30S ALONG THE FOOTHILLS/ROANOKE...WITH SOME MIXING.
8H TEMPS WILL BE COOLER...SO OVERALL LOOKING AT HIGHS THURSDAY IN
THE MOUNTAINS ABOUT 5 TO 10 DEGREES COOLER THAN TODAY...WHILE THE
PIEDMONT THANKS TO DOWNSLOPE AND MORE SUN REMAIN MILD FOR LATE
JANUARY. HIGHS RANGING FROM THE UPPER 30S/LOWER 40S WEST TO LOWER
50S IN THE NC FOOTHILLS/PIEDMONT INTO SOUTHSIDE VA.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 215 PM EST WEDNESDAY...
COMPLEX SCENARIO IS AT HAND FOR THIS PORTION OF THE FORECAST. FOR
THE PAST SEVERAL DAYS...MODEL GUIDANCE HAS BEEN OFFERING A COASTAL
SYSTEM THAT PROGRESSIVELY HAS BECOME ONE WITH A GREATER IMPACT ON
OUR REGION IN TERMS OF THE POTENTIAL FOR WINTRY WEATHER. THE SAME
HOLDS TRUE TODAY WITH THE LATEST 12Z/7AM GUIDANCE.
THE VARIOUS GUIDANCE SOLUTIONS ARE NOT TOO DIFFERENT FROM EACH OTHER
IN TERMS OF ARRIVAL AND DEPARTURE...PERHAPS VARYING BY 3 TO 6 HOURS
FOR THE ONSET AND AROUND 6 HOURS FOR THE DEPARTURE. WE ARE STILL
OFFERING A FORECAST THAT BRINGS LIGHT PRECIPITATION INTO THE FAR
SOUTHWEST PORTION OF THE FORECAST AREA LATE THURSDAY
NIGHT...SPREADING NORTH DURING THE DAY FRIDAY...AND HAS THE BULK OF
THE NON-UPSLOPE PRECIPITATION EXITING BY MID-DAY SATURDAY. LINGERING
UPSLOPE SNOW SHOWERS ACROSS SOUTHEAST WEST VIRGINIA ARE FORECAST BY
ALL THE GUIDANCE SATURDAY AFTERNOON THROUGH SATURDAY NIGHT.
BETWEEN EARLY FRIDAY MORNING AND EARLY SATURDAY THE PRECIPITATION
TYPE HAS BEEN A FORECAST CHALLENGE...ALONG WITH THE SUBSEQUENT
MEASURABLE WINTRY PRECIPITATION. THE NAM CONTINUES TO BE AN OUTLIER
WITH A VERY PROGRESSIVE 85H JET SCREAMING INTO THE REGION FRIDAY
AFTERNOON AND EARLY EVENING WITH MODERATING 85H TEMPS AS HIGH AS +8
C OVER DANVILLE VA BY MIDNIGHT FRIDAY NIGHT WITH THE 0C 85H TEMP AS
FAR NORTHWEST AS THE WV/VA BORDER. THE GFS/ECWMF/CMC ALL HAVE A LESS
AGGRESSIVE 85H JET...AND THUS...LESS OF A SURGE OF WARM AIR
ADVECTION AT THAT AND OTHER LOWER LEVELS. THIS KEEPS MORE OF THE
AREA AT OR BELOW 0C AT 85H. THE VISUAL CONSENSUS BETWEEN THE
GFS/ECMWF/CMC WOULD BE THE GFS AS THE ECMWF IS A LITTLE MILDER AND
THE CMC IS COLDER. THE P-TYPE IN THE FORECAST WILL REFLECT A TOP
DOWN APPROACH THAT MAKES USE OF THE GFS T/TD PROFILE. QPF AMOUNTS
WILL REFLECT THAT OFFERED BY WPC WITH SOME ADJUSTMENTS UPWARD ALONG
THE SOUTHERN BLUE RIDGE TO ACCOUNT FOR THE AFFECTS OF UPSLOPE
TRAJECTORIES FRIDAY EVENING. PROBABILITY OF PRECIPITATION WILL REFLECT
CLOSELY TO THAT OFFERED BY PRECIPITATION FIELDS AND TIMING OF THE
GFS.
WITH ALL THIS IN MIND...THE BIGGEST ADJUSTMENT TO OUR FORECAST WILL
BE A GREATER INCLUSION OF SLEET IN THE FORECAST...ESPECIALLY ACROSS
THE SOUTHWESTERN PORTIONS OF THE AREA ON FRIDAY...AND AREAS ALONG
AND NEAR THE ROUTE 460 CORRIDOR FRIDAY NIGHT. THE FORECAST WILL ALSO
REFLECT MORE WHITE RAIN SNOW DURING THE DAY FRIDAY IN THE WEST.
GIVEN HOW MILD OUR TEMPERATURES HAVE BEEN AS OF LATE...CONFIDENCE IS
LOW THAT SNOW OR SLEET WILL ACCUMULATE TO ANY SUBSTANTIAL DEGREE ON
FRIDAY. PLAIN RAIN WILL BE FORECAST ON FRIDAY FOR AREAS EAST OF THE
BLUE RIDGE.
FRIDAY NIGHT INTO EARLY SATURDAY MORNING WILL BE THE TIME PERIOD OF
FOCUS FOR MEASURABLE WINTRY PRECIPITATION. ACROSS THE
MOUNTAINS...AND THE PIEDMONT ALONG AND NORTH OF ROUGHLY ROUTE 460
LOOKS TO BE A SNOW/SLEET MIXTURE. THE FARTHER NORTH IN THIS AREA THE
BETTER CHANCE FOR PURE SNOW. CLOSER TO SOUTHSIDE VIRGINIA AND
ADJOINING PORTIONS OF NORTH CENTRAL NORTH CAROLINA WILL MORE LIKELY
SEEN A PLAIN COLD RAIN.
FORECAST SNOWFALL AMOUNTS FOR THIS PACKAGE WILL BE GREATEST ALONG
AND NORTH OF INTERSTATE 64 IN SOUTHEAST WEST VIRGINIA AND SOUTHWEST
VIRGINIA WITH TWO TO FOUR INCHES BEING COMMON. FOR THE HIGHER
ELEVATIONS OF WESTERN PARTS OF GREENBRIER COUNTY EXPECT AMOUNTS IN
THE FOUR TO SIX INCH RANGE. ELSEWHERE ACROSS THE MOUNTAINS...LESS
THAN ONE TO TWO INCHES WILL BE MORE PROBABLE. AREAS OF THE PIEDMONT
NORTH OF ROUGHLY THE ROANOKE RIVER WILL BE GENERALLY LESS THAN AN
INCH. IF THIS FORECAST HOLDS THROUGH THE NEXT OR NEXT COUPLE OF
FORECAST SHIFTS...WINTER WEATHER HEADLINES WOULD BE NEEDED FOR AN
AREA ROUGHLY ALONG AND NORTH OF A LINE FROM HINTON WV TO LEXINGTON
OR AMHERST VA. WILL CONTINUE TO HIGHLIGHT THE THREAT IN THE
HAZARDOUS WEATHER OUTLOOK.
SATURDAY AFTERNOON INTO SATURDAY NIGHT THE AXIS OF THE PARENT UPPER
TROUGH CROSSES THE REGION AND WINDS SHIFT ABRUPTLY NORTHWEST AND
START TO INCREASE. 85H LEVEL WINDS A PROGGED TO BE IN THE 40-45 KT
RANGE FROM ROUGHLY NOON TO MIDNIGHT. THIS WILL ACTIVATE THE UPSLOPE
SNOW MACHINE AND PRODUCE ISOLATED TO SCATTERED SNOW SHOWERS FROM
SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH
CAROLINA. ADDITIONAL LIGHT ACCUMULATES OF SNOW WILL BE POSSIBLE
ALONG THE PREFERRED WESTERN SLOPES. ASSOCIATED FLURRIES MAY CARRY
DOWNSTREAM TO THE CREST OF THE BLUE RIDGE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 200 PM EST WEDNESDAY...
COASTAL LOW OFF THE NEW ENGLAND COAST SUNDAY MORNING WILL CONTINUE
TO PUSH EAST INTO THE ATLANTIC OCEAN DEPARTING INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK. UPSLOPE SNOW SHOWERS WILL CONTINUE IN THE
WAKE OF THE COASTAL SYSTEM. A FAST MOVING ALBERTA CLIPPER WILL DROP
SOUTHEAST AND WILL BRING MORE SNOW AND COLDER TEMPERATURES TO THE
REGION.
850MB TEMPERATURES LOOK COLD ENOUGH TO HAVE MOST PRECIPITATION IN
THE FORM OF SNOW WITH THIS CLIPPER. THE PROJECT PATH OF THE STORM
WITH THE BEST DYNAMIC AND MOISTURE IS JUST NORTH OF THE REGION. THE
HEAVIEST SNOW SHOULD FALL ACROSS NORTHERN WEST VIRGINIA...NORTHERN
VIRGINIA AND MARYLAND REGION...CLOSER TO THE MASON-DIXON LINE. FOR
OUR AREA...ADDITIONAL ACCUMULATING SNOW WILL CONTINUE ESPECIALLY IN
THE NORTHWEST MOUNTAINS WITH POTENTIAL FOR SNOW OUT TOWARD THE BLUE
RIDGE. ADVISORY LEVEL SNOWS MAY BE POSSIBLE ALONG THE WESTERN SLOPES
ESPECIALLY SUNDAY NIGHT INTO MONDAY. A LEE LOW REFORMATION IS
EXPECTED ALONG OR OFF THE EAST COAST MONDAY AND THIS SYSTEM
TRACKS NORTHEAST INTO TUESDAY.
THE UPPER TROUGH PERSISTS ALONG THE EAST COAST INTO MIDWEEK. SEVERAL
ADDITIONAL NORTHWEST FLOW DISTURBANCES OR ALBERTA CLIPPERS ARE
SLATED TO IMPACT THE REGION THROUGHOUT THE WEEK KEEPING THE THREAT
FOR WINTER PRECIPITATION HIGH. IT CERTAINLY APPEARS MORE WINTRY THAN
THIS PAST WEEK HAS BEEN. WITH A NEARLY FULL LATITUDE EAST COAST
UPPER TROF ANTICIPATED...TEMPERATURES WILL REMAIN BELOW NORMAL
DURING THE EXTENDED PERIOD.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 643 PM EST WEDNESDAY...
AN UPPER LEVEL DISTURBANCE WILL PASS TO OUR NORTH TONIGHT.
THIS SHOULD RESULT IN SOME LOWER CIGS FOR LWB/BLF OVERNIGHT.
CIGS AT BLF COULD LOWER TO SUB 1KFT BY 10Z...THEN RISE ABOVE TO
MVFR AFTER 15Z. MVFR SCT TO BKN CLOUDS ARE POSSIBLE AT LWB AND
BCB THURSDAY MORNING. OTHERWISE...VFR CONDITIONS WILL PREVAIL.
OUTSIDE OF THE TAF SITES...IN THE WESTERN UPSLOPE FAVORED
LOCATIONS ESPECIALLY SOUTHEAST WEST VIRGINIA A FEW SNOW FLURRIES
ARE POSSIBLE. THIS IS SUPPORTED BY HRRR AND RNK WRFARW.
HIGH PRESSURE WILL MOVE SOUTH OF THE GREAT LAKES ON THURSDAY
AFTERNOON...PASSING ACROSS NEW ENGLAND AND OFF SHORE THURSDAY
NIGHT...RETURNING THE MOUNTAINS TO VFR. MEANWHILE...A DEEP LOW
PRESSURE SYSTEM WILL DEVELOP ALONG THE GULF COAST THURSDAY
NIGHT...RADIATING MOISTURE NORTHWARD ALONG THE APPALACHIAN CHAIN.
MEDIUM TO HIGH CONFIDENCE OF CEILINGS...VISIBILITIES AND WINDS
DURING THE TAF PERIOD.
MODEL TRENDS ARE KEEPING OUR AREA WITH EITHER RAIN MAINLY EAST OF
THE BLUE RIDGE...AND WINTRY WEATHER TO RAIN BACK TO WINTRY WEATHER
IN THE MOUNTAINS. CONFIDENCE IS HIGH THAT THE ENTIRE REGION WILL
SEE SUB VFR CONDITIONS WITH THIS SYSTEM...QUESTION BEING PTYPE.
AVIATION INTERESTS SHOULD CONTINUE TO MONITOR LATER FORECASTS BUT
THE OUTLOOK FOR FRI-SAT DOES NOT LOOK GOOD FOR FLYING ALONG AND
EAST OF THE APPALACHIANS. AS THE STORM STRENGTHENS INTO SATURDAY
GUSTY NW WINDS WILL ENSUE LEADING TO SVR TURBULENCE IN THE
MOUNTAINS AND MID ATLANTIC NWD.
BY SUNDAY WILL SEE IMPROVING CONDITIONS EAST OF THE
MOUNTAINS...WITH LINGERING UPSLOPE CLOUDS AND POSSIBLE SUB VFR
CIGS AT BLF/LWB....WHICH COULD CONTINUE TO MONDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF/WP
NEAR TERM...WP
SHORT TERM...DS
LONG TERM...KK
AVIATION...KK/NF/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1143 AM CST TUE JAN 20 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 337 AM CST TUE JAN 20 2015
PCPN TRENDS AND TYPE WILL BE THE MAIN FCST CONCERNS.
A S/W TROF OVER SW WI/NE IA/NW IL AND SOME MID-LEVEL (800-700 MB)
FRONTOGENETIC FORCING WAS PRODUCING BANDED SNOWFALL AND ACCUMS OF
1-2 INCHES OVER C/EC WI EARLY THIS MORNING. SOME FZDZ WAS ALSO
BEING REPORTED IN AREAS WHERE THE SNOW WAS TAPERING OFF. WV
IMAGERY AND RUC ANALYSES SHOWED AN UPPER LOW OVER NORTH DAKOTA.
THIS SYSTEM IS EXPECTED TO AFFECT MAINLY C/EC WI TONIGHT INTO
WEDNESDAY.
SNOW SHOULD TAPER OFF OVER ALL BUT EAST CENTRAL WI BY DAYBREAK...
BUT THERE WILL BE SOME PATCHY FZDZ OVER MAINLY C/EC WI INTO THE
MORNING HOURS. IT IS POSSIBLE THAT A LITTLE FZDZ MAY LINGER OVER
OUR FAR SW/S COUNTIES THROUGH THE DAY...BUT MOST PLACES SHOULD
SEE A BREAK IN THE PCPN. EXPECT HIGH TEMPS TO WARM INTO THE
20S...WITH UPPER 20S AND LOWER 30S SOUTH.
AS THE NORTH DAKOTA UPPER LOW TRACKS TOWARD SW WI...SOME LIGHT
SNOW AND FZDZ IS EXPECTED TO REDEVELOP OVER CENTRAL AND PARTS OF
EAST CENTRAL WI DURING THE EVG AND OVERNIGHT. SNOW ACCUMS SHOULD
BE UNDER AN INCH...WITH THE HIGHEST ACCUMS IN OUR FAR SW COUNTIES.
PATCHY LIGHT SNOW WILL CONTINUE IN C/EC WI INTO WEDS MORNING...
THEN GRADUALLY DECREASE AS THE UPPER LOW TRACKS SE OF THE REGION
IN THE AFTERNOON. SOME LIGHT LAKE-EFFECT MAY DEVELOP OVER NC WI
AS LIGHT NORTH WINDS DEVELOP. LOWS TONIGHT SHOULD BE IN THE TEENS
AND LOWER 20S...WITH HIGHS MAINLY 25 TO 30 ON WEDNESDAY.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 337 AM CST TUE JAN 20 2015
500MB RIDGE WILL DOMINATE THE WEATHER PATTERN WITH SPLIT FLOW
NOTED ACROSS THE EASTERN HALF OF NORTH AMERICA. THIS PATTERN
WILL LEAD TO THE MORE SIGNIFICANT STORMS STAYING WELL SOUTH
OF THE AREA WHILE WEAK CLIPPER SYSTEMS WILL DROP SOUTHEAST OUT OF
CANADA. THE BIGGEST BENEFIT WITH THIS PATTERN IS THE TRUE ARCTIC
AIR WILL REMAIN UP IN CANADA...ALTHOUGH THEIR ARE HINTS IT MAY
DROP SOUTH INTO OUR AREA BEYOND THE FORECAST PERIOD.
FIRST CLIPPER SYSTEM AND ASSOCIATED COLD FRONT WILL MOVE ACROSS
THE AREA ON FRIDAY. PRECIPITATION TYPE MAY BE AN ISSUE WITH
WARM AIR FLOWING INTO THE SYSTEM. BUFKIT SOUNDINGS WOULD
SUGGEST PARTIAL OR COMPLETE MELTING OF ANY SNOWFLAKES AND
MAY REFREEZE BELOW 850MB DUE TO DRY AIR AROUND 925MB. ADDED
SLEET TO THE FORECAST ON FRIDAY...AND A LITTLE RAIN ACROSS THE
EAST FRIDAY AFTERNOON DUE TO MILD TEMPERATURES AHEAD OF COLD
FRONT.
THE NEXT CLIPPER SYSTEM FOR SATURDAY NIGHT AND SUNDAY APPEARS
TO BE MOVING SOUTHWEST OF THE AREA. WILL HAVE THE HIGHEST CHANCES
FOR SNOW ACROSS THE SOUTH. LATER SHIFTS MAY BE ABLE TO REMOVE
CHANCES ACROSS PORTIONS OF THE NORTH IF THIS SCENARIO HOLDS TRUE.
ANOTHER ONE OR TWO CLIPPER SYSTEMS WILL MOVE ACROSS THE REGION
EARLY NEXT WEEK. IT IS TOO FAR OUT TO PINPOINT WHERE HIGHEST
CHANCES OF LIGHT SNOW WOULD OCCUR ACROSS THE REGION DUE TO
TIMING AND LOCATION DIFFERENCES. DID RAISE TEMPERATURES UP A
DEGREES OR TWO FROM THURSDAY INTO THE WEEKEND.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1142 AM CST TUE JAN 20 2015
DRY CONDITIONS ARE EXPECTED FOR THE EARLY AFTERNOON HOURS...AS THE
AREA IS IN BETWEEN WEAK WEATHER SYSTEMS. THE NEXT UPPER LEVEL
DISTURBANCE AND SURFACE LOW PRESSURE WILL PUSH ACROSS SOUTHERN MN
AND SOUTHERN WI TONIGHT INTO WEDNESDAY AM. THE SYSTEM IS TRACKING
SLIGHTLY SLIGHTLY FARTHER SOUTH THAN THE SYSTEM LAST NIGHT...SO
MOST OF THE ACCUMULATING SNOW WILL PASS SOUTH OF THE AREA...
HOWEVER WILL INCLUDE SOME -SN WITH MVFR/VFR VSBYS TO COVER ANY
LIGHT SNOW OR FLURRIES THAT MAKE IT INTO AUW/CWA/GRB/ATW/MTW. THE
CHANCES FOR ANY ACCUMULATIONS INCREASE AS YOU MOVE SOUTH OF A
MARSHFIELD TO OSHKOSH LINE. MODELS SOUNDINGS SHOW A THREAT OF
FREEZING DRIZZLE MIXING IN WITH THE LIGHT SNOW AS MID-LEVEL
MOISTURE WILL BE LACKING ON THE NORTH SIDE OF THE LOW PRESSURE
SYSTEM. WILL MENTION OF -FZDZ ALONG WITH -SN TO COVER THIS
THREAT...BUT CONFIDENCE IS LOW. RHI LOOKS TO REMAIN DRY TONIGHT...
THEN THERE IS A SMALL CHANCE OF A SNOW SHOWER WEDNESDAY PM AS SOME
LAKE EFFECT ACTIVITY FROM LAKE SUPERIOR COULD APPROACH NORTH-
CENTRAL WI...BUT WILL NOT INCLUDE A MENTION AT THIS TIME. AS FOR
CLOUDS...THICK CLOUD COVER IS FORECAST TO REMAIN OVER THE AREA
THROUGH WEDNESDAY. HIGH IFR TO LOW MVFR CIGS ARE EXPECTED TONIGHT
INTO WEDNESDAY AM. A CLEARING LINE IS APPROACHING FROM THE WI/MI
BORDER...BUT THAT WILL COME UP WELL SHORT OF MAKING INTO THE TAF
SITES. SOME PATCHY FOG IS POSSIBLE OVERNIGHT ACROSS NORTHERN WI AS
WELL.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....KIECKBUSCH
LONG TERM......ECKBERG
AVIATION.......BERSCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
211 PM MST TUE JAN 20 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 300 PM MST TUE JAN 20 2015
COLD AIR MASS TO REMAIN IN PLACE WITH 700MB TEMPERATURES OF -14 TO
-16C TODAY THROUGH WEDNESDAY NIGHT. SURFACE TEMPERATURES COLD WITH
OVERNIGHT LOWS IN THE SINGLE DIGITS TO LOW TEENS AND DAYTIME HIGHS
STRUGGLING TO GET ABOVE FREEZING. THIS IS DUE TO A SLOW MOVING UPPER
LOW THAT TRACKS ACROSS COLORADO THROUGH THURSDAY THAT KEEPS A NORTH
WIND OVER THE AREA.
WILL STAY DRY FOR THE MOST PART...MAYBE SOME SCATTERED SNOW SHOWERS
OVER THE SNOWY AND SIERRA MADRE RANGES...BUT THATS ABOUT IT. START
TO SEE A CHANGE THURSDAY NIGHT AS THE LOW FINALLY TRACKS OFF TO THE
SOUTHEAST WITH UPPER LEVEL RIDGING BUILDING BACK OVER WYOMING. 700MB
TEMPERATURES WARM UP ABOUT 8 DEGREES C INTO THURSDAY MORNING TO -6
TO -10C. NO ISSUES WITH WINDS OR PRECIP THROUGH THE SHORT TERM.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 300 PM MST TUE JAN 20 2015
THE LATEST MEDIUM RANGE MODELS AND THEIR ENSEMBLES ARE IN GENERAL
AGREEMENT. THE LARGE SCALE PATTERN WILL BE DOMINATED BY A WESTERN
CONUS UPPER RIDGE AND EASTERN CONUS UPPER TROUGH. CONSEQUENTLY...
NORTHWEST FLOW ALOFT WILL PREVAIL. NO SENSIBLE WEATHER IS FORECAST
FRIDAY WITH BREEZY NORTHWEST WINDS. DOWNSLOPE FLOW LEE OF THE LARAMIE
RANGE WILL PUSH THE MERCURY INTO THE 40S DURING THE AFTERNOON. A
CLIPPER LOW PRESSURE SYSTEM AND COLD FRONT WILL MOVE SOUTHEAST
ACROSS THE NORTHERN PLAINS AND MIDWEST LATE SATURDAY THROUGH
SUNDAY. THE ECMWF/GEM ARE PRODUCING SOME LIGHT PRECIPITATION OVER
EAST CENTRAL WY AND THE SOUTHEAST WY MOUNTAINS SATURDAY AFTERNOON
AND NIGHT. AS THIS CLIPPER PASSES TO THE NORTHEAST OF THE CWFA
SATURDAY...THE PRESSURE GRADIENT TIGHTENS ACROSS SOUTHEAST WY WITH
WEST WINDS GUSTING TO 40 KT THROUGH WIND PRONE AREAS. DOWNSLOPE
FLOW ONCE AGAIN WILL PROVIDE ABOVE NORMAL HIGH TEMPERATURES. UPPER
RIDGE AMPLIFIES SUNDAY WITH ANOTHER SHORTWAVE MOVING SOUTHEAST
THROUGH THE NORTHERN HIGH PLAINS. GFS DEPICTS LITTLE OR NO
PRECIPITATION WHILE THE ECMWF/GEM PRODUCE A BAND OF LIGHT QPF FROM
NORTHERN WY INTO NORTHWEST NE. REGARDLESS...THE MAJORITY OF THE
CWFA WILL BE DRY SUNDAY...EXCEPT FOR ISOLATED OROGRAPHIC SNOW
SHOWERS OVER THE SNOWY/SIERRA MADRE RANGES. AS THE UPPER RIDGE
MOVES OVERHEAD EARLY NEXT WEEK...EXPECT DRY AND UNSEASONABLY MILD
CONDITIONS WITH HIGHS INTO THE 50S FOR THE PLAINS. WEST TO NORTHWEST
WINDS WILL BE BREEZY...MAINLY DURING THE DAYTIME HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1050 AM MST TUE JAN 20 2015
EXPECT CIGS BETWEEN 5000 AND 10000 KT AGL ALONG/EAST OF LARAMIE RANGE
THIS AFTERNOON...BECOMING SCATTERED THIS EVENING. LATEST HRRR GUIDANCE
BRINGS IN LOWER CIGS WEST OF LARAMIE RANGE LATE THIS AFTERNOON WITH
RWL/SAA AIRFIELDS FLIRTING WITH MVFR THROUGH WEDNESDAY MORNING. IT
WILL BE BREEZY THIS AFTERNOON WITH W-NW SURFACE WINDS GUSTING TO 25
KT...HIGHER IN AND NEAR THE SE WY MOUNTAINS. WINDS WILL DIMINISH THIS
EVENING.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MST TUE JAN 20 2015
MINIMAL FIRE WEATHER CONCERNS AS A COLD FRONT WILL REMAIN OVER THE
AREA THROUGH THE NEXT COUPLE DAYS. WILL SEE SOME MOUNTAIN SNOW...BUT
ACCUMULATIONS WILL BE LIGHT. AFTERNOON HUMIDITIES WELL ABOVE CRITICAL
THRESHOLDS WITH EXCELLENT OVERNIGHT RECOVERIES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...GCC
LONG TERM...MJ
AVIATION...MJ
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1056 AM MST TUE JAN 20 2015
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 400 AM MST TUE JAN 20 2015
QUIET WEATHER THROUGH THURSDAY NIGHT WITH VERY FEW FORECAST CONCERNS.
A STRUNG OUT AREA OF VORTICITY WILL PROVIDE ENOUGH LIFT FOR SOME
LIGHT SNOW TODAY. VERY LITTLE IN THE WAY OF ACCUMULATION IS EXPECTED
BUT THERE IS THE POTENTIAL FOR A FEW VERY NARROW BANDS OF SNOW WHICH
COULD PRODUCE SOME ACCUMULATION IN THE PLAINS OF SOUTHEAST WYOMING.
THERE IS SOME LOW LEVEL INSTABILITY IN PLACE TODAY BUT WITH WEAK
FRONTOGENESIS AND WEAK UPPER LEVEL SUPPORT...EVEN BANDED PRECIPITATION
IS NOT A SURE THING.
COOLER AIR WILL PUSH INTO THE AREA TODAY AND TONIGHT WITH THE COLDEST
AIR IN PLACE WEDNESDAY WITH HIGHS MAINLY IN THE 20S AND LOWS IN THE
SINGLE DIGITS WEDNESDAY NIGHT. DID NOT MENTION CHANCES FOR PRECIPITATION
WEDNESDAY BUT GIVEN COOL NORTHWEST FLOW ALOFT AND A WEAK SHORTWAVE
THERE COULD BE SOME SNOW FLURRY ACTIVITY...ESPECIALLY LATE MORNING
AND AFTERNOON AS THE LOW LEVELS DESTABILIZE.
NO CHANCES FOR PRECIPITATION THURSDAY UNDER CLEAR SKIES AND WESTERLY
DOWNSLOPE FLOW. TEMPERATURES WILL REBOUND WITH THE CLEAR SKIES AND
WARMING TEMPERATURES ALOFT AS A BROAD UPPER RIDGE BEGINS TO BUILD
ACROSS THE ROCKIES.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 400 AM MST TUE JAN 20 2015
SOMEWHAT MILDER THAN AVERAGE TEMPERATURES EXPECTED OVERALL ACROSS
THE CWA DURING THIS PERIOD UNDER A GENERALLY NW FLOW ALOFT BETWEEN
RIDING OVER THE WESTERN CONUS AND DEEP TROFFING ACROSS THE EASTERN
CONUS. BEST CHANCE FOR ANY PCPN LOOKS TO BE SATURDAY NIGHT AS AN
UPPER TROF DROPS RATHER QUICKLY SE IN THE FLOW AND ACROSS THE AREA.
ARCTIC AIR WILL REMAIN CUT OFF AND WELL TO THE NORTH OF THE AREA
WITH MODIFIED PACIFIC AIR CONTINUING ACROSS THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1050 AM MST TUE JAN 20 2015
EXPECT CIGS BETWEEN 5000 AND 10000 KT AGL ALONG/EAST OF LARAMIE RANGE
THIS AFTERNOON...BECOMING SCATTERED THIS EVENING. LATEST HRRR GUIDANCE
BRINGS IN LOWER CIGS WEST OF LARAMIE RANGE LATE THIS AFTERNOON WITH
RWL/SAA AIRFIELDS FLIRTING WITH MVFR THROUGH WEDNESDAY MORNING. IT
WILL BE BREEZY THIS AFTERNOON WITH W-NW SURFACE WINDS GUSTING TO 25
KT...HIGHER IN AND NEAR THE SE WY MOUNTAINS. WINDS WILL DIMINISH THIS
EVENING.
&&
.FIRE WEATHER...
ISSUED AT 400 AM MST TUE JAN 20 2015
NO FIRE WEATHER CONCERNS WITH LIGHT WINDS ACROSS THE AREA THE NEXT
SEVERAL DAYS. COOLER TEMPERATURES TUESDAY AND WEDNESDAY THEN A
WARMING TREND INTO THE WEEKEND. A FEW LIGHT SNOW SHOWERS POSSIBLE
TODAY OTHERWISE DRY THROUGH AT LEAST THURSDAY NIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...SML
LONG TERM...RE
AVIATION...MJ
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS DES MOINES IA
335 AM CST THU JAN 22 2015
.SYNOPSIS...
ISSUED AT 318 AM CST THU JAN 22 2015
HIGH PRESSURE RIDGE WILL MOVE THROUGH THE AREA TODAY WITH THE
NEXT IN THE SERIES OF FAST MOVING LOW PRESSURE SYSTEMS DROPS
SOUTHEAST THROUGH ONTARIO ON FRIDAY. ANOTHER SYSTEM WILL MOVE OUT
OF NRN ALBERTA AND BRUSH NERN IA SATURDAY NIGHT...AND MOVE INTO
THE MID ATLANTIC SEABOARD BY SUNDAY EVENING. JET STREAM WILL
REMAIN NORTH OF THE AREA THROUGH THE FORECAST PERIOD AS WILL THE
STORM TRACK.
&&
.SHORT TERM /TODAY/...
ISSUED AT 318 AM CST THU JAN 22 2015
MAIN FORECAST CONCERN TODAY DEALT WITH CLOUD COVER AND
TEMPERATURES. THE STRATUS DECK LOOKS TO GRADUALLY THIN OUT AND
DISSIPATE THROUGHOUT THE DAY AND SHOULD SEE MORE SUNSHINE THAN CLOUD
COVER BY AROUND 19Z-20Z. BOTH THE HRRR AND HOPWRF HAVE CLOUD COVER
DISSIPATING B/T 18-21Z THIS AFTERNOON FROM SOUTHWEST IOWA TO THE
NORTHEAST. THIS COINCIDES WITH THE SURFACE HIGH SHIFTING OVER MUCH
OF THE STATE BY MIDDAY AND ADVECTS IN SOME DRIER AIR AND ALLOWS THE
INVERSION TO WEAKEN. THUS...WENT SLIGHTLY ABOVE PREVIOUS FORECAST
OVER THE CENTRAL TO SOUTHWEST WHERE THE CLOUD COVER SHOULD CLEAR OUT
A LITTLE SOONER. WENT CLOSER THE MAVMOS/SREF FOR MAX TEMPS TODAY.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 318 AM CST THU JAN 22 2015
NOT A LOT OF CHANGE WITH THE IDEAS OF THE MODELS FROM THE PAST FEW
DAYS INTO TODAY. WEATHER SYSTEM OUT OF ALBERTA WILL BRING A CHANCE
FOR MIXED PRECIPITATION OVER THE NORTHEAST...WITH MOSTLY RAIN
OVER THE SOUTHWEST SATURDAY NIGHT INTO SUNDAY. NO REAL COLD AIR
FOLLOWING THE SYSTEM AND WILL SEE MILD LATE JANUARY WEATHER
CONTINUE.
A THIRD IN THE SERIES OF LOW PRESSURE SYSTEMS WILL PASS WELL TO
THE NORTH OF THE AREA FOR MID WEEK...BRINGING IN VERY MILD AIR.
TUE WILL BE QUITE WARM...MAINLY SOUTHWEST...WITH MORE WIDESPREAD
WARMING ON WED. THE ECMWF IS SHOWING THE +16 AT H8 MAKING IT INTO
THE STATE. WENT WARMER THAN MOS AND MORE IN LINE WITH THE ECMWF
OMS FORECASTS FOR WED. ALL SIGNS LOOK GOOD FOR GOOD WARMING OVER
NON-SNOW COVERED AREAS.
THE END OF THE WEEK WILL FEATURE A CHANGE IN THE PATTERN.
INDICATIONS POINT TO A STRONG PUSH OF COLD AIR BY THE
WEEKEND...LIKELY RIVALING THE COLD OUTBREAK WE SAW THE WEEK OF
THE 5TH.
&&
.AVIATION...22/06Z
ISSUED AT 1135 PM CST WED JAN 21 2015
MVFR CIGS ACROSS NORTHERN IA WITH VFR BREAKS ACROSS THE SOUTH.
WILL HAVE PERIOD OF MVFR THROUGHOUT THE NIGHT THEN GRADUAL
TRANSITION TO VFR ENTIRE AREA BY WED AFTERNOON AND EVENING. BRIEF
IFR IS POSSIBLE AT KALO/KMCW OVERNIGHT. LIGHT NORTHWEST WINDS
TONIGHT BECOMING WEST TO SOUTHWEST ON WEDNESDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS JAN 15
SHORT TERM...PODRAZIK
LONG TERM...MS JAN 15
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
429 AM EST THU JAN 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 429 AM EST THU JAN 22 2015
A CLOUDY SKY COVERS ALL OF UPPER MICHIGAN EARLY THIS MORNING...AS
ABUNDANT LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE STRENGTHENING
SUBSIDENCE INVERSION (SEEN ON 00Z KINL SOUNDING) FROM THE HIGH
PRESSURE RIDGE OVER NORTHERN MINNESOTA. RAP ANALYSIS SHOWS A -12C
850MB THERMAL TROUGH SLIDING ACROSS CENTRAL/EASTERN LAKE SUPERIOR
EARLY THIS MORNING (ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
NORTHERN ONTARIO AND BRUSHING NORTHERN LAKE SUPERIOR) AND AIDING
WEAK LAKE EFFECT SNOW SHOWERS IN THE NORTHWEST WIND SNOW BELTS OVER
EASTERN UPPER MICHIGAN. OVERALL THESE ARE FAIRLY WEAK AND DISJOINTED
DUE TO THE MARGINAL DELTA-T VALUES AND WEAK LOW LEVEL LAPSE RATES.
THOSE MARGINAL FEATURES HAVE ALSO LEAD TO OCCASIONAL PERIODS OF
FREEZING DRIZZLE LAST EVENING OVER THE KEWEENAW AND ALSO OVER THE
NORTH CENTRAL THROUGH THE NIGHT. WILL INCLUDE A PATCHY FREEZING
DRIZZLE MENTION FOR THE NEXT COUPLE OF HOURS...BUT EXPECT THERE TO
BE LITTLE TO NO IMPACT WITH THE PRECIP BEING PREDOMINATELY SNOW.
UNDER THE CLOUDY SKIES...TEMPERATURES HAVE BEEN SLOW TO FALL THROUGH
THE NIGHT...WITH 3AM TEMPERATURES STILL IN THE LOWER 20S.
THE HIGH PRESSURE RIDGE OVER MINNESOTA WILL QUICKLY SLIDE EAST
ACROSS UPPER MICHIGAN TODAY...AS THE PARENT HIGH MOVES FROM THE
CENTRAL PLAINS TO THE OHIO RIVER VALLEY. THIS WILL LEAD TO STEADILY
BACKING LOW LEVEL WINDS THIS MORNING AND SHIFT ANY REMAINING LAKE
EFFECT SNOW OVER THE EAST OFFSHORE. THE BIGGEST QUESTION WITH THE
FORECAST TODAY IS WHAT WILL HAPPEN TO THE CLOUDS. MOST MODELS ARE
INDICATING THAT THE LOW CLOUDS WILL SCATTER OUT LATE THIS MORNING
AND INTO THE AFTERNOON. DO HAVE SOME CONCERN WITH THAT DUE TO THE
UPSTREAM OBS STILL INDICATING LOW CLOUDS INTO EASTERN MINNESOTA AND
WESTERN WISCONSIN...ALONG WITH THE STRENGTHENING SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH PRESSURE RIDGE MOVING THROUGH.
BUT WITH THE SOUTHWESTERLY FLOW INCREASING MIXING AND THE MOISTURE
LAYER BECOMING THIN...DID TREND THE FORECAST TOWARDS PARTLY CLOUDY.
THIS SITUATIONS ARE TRICKY...AS SOME AREAS WILL LIKELY CLEAR OUT
COMPLETELY (AIDED BY DOWNSLOPING SOUTHWESTERLY WINDS) WHILE THERE
COULD STILL BE POCKETS OF CLOUDY SKIES. AS THE LOW CLOUDS SCATTER
OUT...HIGH CLOUDS WILL BE THICKENING OVER THE AREA THIS
AFTERNOON/EVENING ASSOCIATED WITH THE APPROACHING CLIPPER SYSTEM.
THUS...WILL GRADUALLY INCREASE THE CLOUDS FROM THE NORTHWEST LATE
THIS AFTERNOON AND CONTINUE THROUGH THE NIGHT. LOWS WILL OCCUR THIS
EVENING AND THEN GRADUALLY WARM OVERNIGHT WITH THE INCREASING
SOUTHWESTERLY FLOW. THAT SOUTHWEST FLOW...WHICH WILL PRODUCE GALES
OVER WESTERN/CENTRAL LAKE SUPERIOR...IS EXPECTED TO LEAD TO GUSTY
CONDITIONS DEVELOPING OVER THE FAR WEST THIS AFTERNOON AND ACROSS
THE AREA TONIGHT. THINK THE STRONGEST GUSTS WILL REMAIN TOWARDS ISLE
ROYALE WHERE THE BEST PRESSURE FALLS ARE LOCATED...BUT STILL SHOULD
SEE SOME GUSTS TO 20-25KTS (AND 30KTS OVER THE KEWEENAW) TONIGHT.
AS THE COLD FRONT ASSOCIATED WITH THE CLIPPER SYSTEM APPROACHES LAKE
SUPERIOR TONIGHT...SHOULD SEE PRECIPITATION DROPPING SOUTHEAST
ACROSS WESTERN/CENTRAL LAKE SUPERIOR OVERNIGHT. SHOULD SEE IT
IMPACTING THE KEWEENAW PENINSULA BETWEEN 9-12Z. HAVE KEPT
PRECIPITATION AS SNOW FOR MOST LAND LOCATIONS THROUGH 12Z...BUT WITH
THE NAM INDICATING A WARM NOSE MOVING INTO WESTERN LAKE SUPERIOR
TOWARDS 12Z...DID ADD A MENTION OF FREEZING RAIN AND SLEET TO THAT
AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 452 PM EST WED JAN 21 2015
A PERSISTENT RIDGE OVER THE WRN CONUS WILL MAINTAIN NW MID/UPPER
LEVEL FLOW ACROSS THE NRN GREAT LAKES THROUGH THE MIDDLE OF NEXT
WEEK. THIS WILL BRING A SERIES OF CLIPPERS INTO THE REGION. IT
APPEARS AT THIS TIME ANY LES FROM THESE CLIPPERS WOULD BE LIGHT AS
ONLY MARGINAL INSTABILITY IS EXPECTED WITH THE COLDEST AIR
REMAINING OVER NE CANADA.
BEGINNING THU NIGHT...CONTINUED STRONG WAA IN SW WIND REGIME WILL
SHUT OFF LES DUE TO LACK OF INSTABILITY. SW WINDS ESPECIALLY OVER
THE WRN AND NCNTRL PORTIONS OF LAKE SUPERIOR WILL INCREASE WITH A
TIGHT GRADIENT BETWEEN A FCST 996 MB LOW MOVING INTO NW ONTARIO AND
1030 MB RIDGE THROUGH THE SRN GREAT LAKES. EXPECT STEADY OR SLOWLY
RISING TEMPS INTO THE LOWER TO MID 20S. WILL KEEP SOME SLIGHT CHC
POPS IN OVER THE KEWEENAW LATE THU NIGHT AS NRN LAKE SUPERIOR WILL
BE ON EDGE STRONG ISENTROPIC ASCENT AND LOWERING CONDENSATION PRES
DEFICITS LEADING TO SATURATION.
FRI AND FRI NIGHT...THE WAA MAY BRING SOME PCPN INTO UPPER MI BUT
ANY AMOUNTS SHOULD BE LIGHT WITH QPF MAINLY AT OR BELOW 0.05 INCH
EQUATING TO SNOW AMOUNTS OF HALF INCH OR LESS. MODELS 290K-295K FCST
SUGGESTS THAT THE BEST LIFT AND SATURATION WOULD OCCUR OVER THE ERN
CWA DURING THE AFTERNOON. HOWEVER...WITH A PROMINENT DRY 925-750 MB
LAYER...ONLY LOWER END 20-30 POPS WERE INCLUDED. COLDER AIR WILL
ONLY GRADUALLY MOVE IN FRI NIGHT WITH NW WINDS BEHIND A SFC TROUGH
AS 850 MB TEMPS DROP TO -6C TO -8C BY 12Z/SAT. SOME LIGHT LAKE
ENHANCED SNOW IS POSSIBLE FOR NW FLOW FAVORED LOCATIONS AS A WEAK
SHORTWAVE MOVES THROUGH WITH DEEPER MOISTURE OVER THE AREA.
SAT...ONLY MARGINALLY COLD AIR WITH 850 MB TEMPS FALLING TO -10C TO
-12C WILL MOVE IN AS A RIDGE BUILDS INTO THE WRN LAKES. DIMINISHING
LOW LEVEL WINDS BECOMING MORE ANTICYCLONIC AND NRLY WITH TIME WILL
ALSO LIMIT POTENTIAL FOR LES ACCUMULATIONS CONSISTENT WITH ONLY
CHANCE POPS.
SAT NIGHT AND SUN...STILL SOME MODEL UNCERTAINTY ON WHERE NEXT
CLIPPER SYSTEM WILL TRACK...ALTHOUGH 12Z MODEL CONSENSUS SUGGESTS
THE SHORTWAVE AND ASSOC SFC LOW WILL TRACK WEST AND SOUTH OF THE
UPPER GREAT LAKES. THE 12Z CANADIAN IS THE OUTLIER AND TRACKS THE
LOW ACROSS THE U.P./WI BDR ON SUNDAY WHICH WOULD BRING WIDESPREAD
SNOW ACROSS MUCH OF THE FCST AREA SAT NIGHT INTO SUNDAY. WILL
CONTINUE ALONG WITH CONSENSUS FCST WHICH IS FAIRLY CONSISTENT WITH
PREV FCST KEEPING CHC POPS CONFINED TO THE FAR WEST WITH SLIGHT CHC
POPS INTO THE CENTRAL AND FOR SOME LINGERING N-NE FLOW LES.
MON INTO WED...ANOTHER CLIPPER SYSTEM IS DUE IN FOR THE EARLY
PORTION OF NEXT WEEK BUT MODELS ARE STILL IN FAIRLY POOR AGREEMENT
WITH THE TIMING/STRENGTH OF THIS WAVE. 12Z GFS SHOWS A STRONGER WAVE
AND ASSOC SFC LOW MOVING THROUGH THE UPPER LAKES ON TUE WHILE THE
12Z ECMWF SHOWS A WEAKER WAVE MOVING WELL NE OF THE UPPER LAKES ON
WED WITH A COLD FRONT MOVING THROUGH LATE WED/WED NIGHT. AT ANY RATE
WILL KEEP LOW CHC POPS (ESPECIALLY ALONG LAKE SUPERIOR) IN FOR MUCH
OF THE EARLY PART OF THE WEEK TO ACCOUNT FOR MODEL UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1157 PM EST WED JAN 21 2015
CURRENT WIDESPREAD COVERAGE OF MVFR CIGS ACROSS THE AREA AND LIGHT
NW FLOW OFF LAKE SUPERIOR SUGGEST MVFR CIGS WILL PREVAIL AT
KIWD/KCMX/KSAW THRU THE NIGHT. EXPECT SOME -SHSN/FLURRIES AS
WELL...BUT VIS WILL REMAIN VFR. PASSAGE OF HIGH PRES RIDGE TODAY
WILL RESULT IN WINDS BACKING TO THE SW...PUSHING MVFR CIGS OUT AND
BRINGING A RETURN OF VFR TO ALL TERMINALS LATE MORNING/EARLY AFTN.
TIGHTENING PRES GRADIENT WILL LEAD TO INCREASING SW WINDS IN THE
AFTN/EVENING. DEPENDING ON DEGREE THAT WINDS REMAIN DECOUPLED...LLWS
WILL BE POSSIBLE IN THE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EST THU JAN 22 2015
A HIGH PRESSURE RIDGE WILL QUICKLY SLIDE EAST ACROSS THE UPPER
GREAT LAKES REGION THIS MORNING...STEADILY BACKING WINDS TO THE
SOUTHWEST. AS THE PRESSURE GRADIENT TIGHTENS THIS AFTERNOON AND
TONIGHT AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH NORTHERN
MANITOBA AND NORTHERN ONTARIO...EXPECT SOUTHWESTERLY GALES OF
35-40KTS OVER PORTIONS OF WESTERN AND CENTRAL UPPER MICHIGAN. BASED
OFF THE STRENGTH OF THE WINDS JUST ABOVE THE SURFACE...WOULDN/T BE
SURPRISED TO SEE SOME 45KT GUSTS AT THE HIGHER PLATFORMS AROUND
ISLE ROYALE. THE GALE WARNING THAT IS IN PLACE LOOKS TO BE IN DECENT
SHAPE...ALTHOUGH DID EXPAND IT SOUTHWEST TO LSZ162. A COLD FRONT
ASSOCIATED WITH THE LOW WILL SWEEP SOUTHEAST ACROSS LAKE SUPERIOR
ON FRIDAY...SHIFTING THE WINDS TO THE NORTHWEST AND BRINGING AN END
TO THE GALES. BEHIND THE FRONT...EXPECT WINDS TO 25-30KTS BEFORE
SHIFTING MORE NORTHERLY BEHIND A SECONDARY TROUGH ON MOVING ACROSS
LAKE SUPERIOR ON SATURDAY. WINDS WILL DIMINISH BEHIND THE SECONDARY
TROUGH AS A HIGH PRESSURE RIDGE SHIFTS SOUTH INTO THE AREA
SATURDAY NIGHT. ANOTHER CLIPPER SYSTEM WILL MOVE OUT OF CANADA AND
THROUGH THE UPPER MISSISSIPPI VALLEY ON SATURDAY NIGHT AND THEN
SLIDE THROUGH WISCONSIN SUNDAY MORNING. THIS WILL KEEP WINDS UP TO
20KTS OUT OF THE NORTH-NORTHEAST. ANOTHER RIDGE WILL BUILD IN
BEHIND THIS CLIPPER AND KEEP WINDS 15KTS OR BELOW SUNDAY NIGHT INTO
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 PM THIS EVENING TO 9 AM EST FRIDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
345 AM CST THU JAN 22 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 345 AM CST THU JAN 22 2015
PRECIP CHANCES AND TYPE WILL AGAIN BE THE PRIMARY CONCERN FOR THE
SHORT TERM.
NORTHWESTERLY FLOW ALOFT WILL CONTINUE...WITH A SFC LOW
STRENGTHENING OVER SOUTHERN CANADA IN RESPONSE TO A SHORTWAVE
TROUGH MOVING THROUGH THAT AREA. THIS WILL INCREASE THE PRESSURE
GRADIENT OVER THE CWA...WITH SOUTHWESTERLY WINDS PICKING UP TO
JUST BELOW ADVISORY CRITERA. THE SOUTHWEST WINDS WILL ALSO BRING
A WARMER AIR MASS BACK INTO THE REGION. WE SHOULD AGAIN GET INTO
THE 20S AND 30S EVEN WITH A COOL START THIS MORNING AND INCREASING
CLOUDS.
TONIGHT...THERE WILL BE A FAIRLY SIGNIFICANT SHORTWAVE DIGGING
FROM MANITOBA INTO NORTHERN ND. THE MODELS ARE A LITTLE MORE
CONSISTENT TODAY ON PUTTING OUT SOME PRECIP TONIGHT AND INTO
TOMORROW MORNING AS THE SHORTWAVE MOVES THROUGH THE CWA. THE RAP IN
FACT HAS SOME PRECIP MOVING IN AS SOON AS LATE AFTERNOON. THINK
THIS IS A BIT OVERDONE GIVEN THE TIME IT TAKES TO SATURATE AND
WILL KEEP POPS OUT UNTIL AFTER 00Z FRIDAY. HAVE SOME 20-30 POPS
MOVING THROUGH TONIGHT BEFORE EXITING TOMORROW MORNING. WHILE THE
AMOUNTS WILL BE LIGHT...THERE WILL BE A VERY STRONG WARM LAYER
ALOFT MOVING IN WITH THE SOUTHWESTERLY WINDS. SFC TEMPS IN THE
EVENING MAY ACTUALLY STILL BE ABOVE FREEZING BUT AS THE BOUNDARY
LAYER COOLS OFF SOME FREEZING RAIN IS DEFINITELY POSSIBLE. TOO
MUCH UNCERTAINTY FOR ANY HEADLINES AT THIS POINT BUT WILL KEEP AN
EYE FOR SOME LIGHT ICE ACCUMULATIONS.
FRIDAY...THE UPPER SHORTWAVE WILL DIG DOWN INTO MN...ALLOWING THE
SFC TROUGH TO MOVE EAST AND WINDS ACROSS THE CWA SHIFT TO THE WEST
AND NORTHWEST ON THE BACKSIDE OF THE LOW. WITH THE WEST WINDS
THINK WE WILL SEE SOME REDUCTIONS IN CLOUDS...AND WITH 850MB TEMPS
STILL WELL ABOVE ZERO C...FRIDAY LOOKS TO BE VERY MILD WITH HIGHS
IN THE 30S AND SOME SPOTS NEAR THE 40 MARK.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU JAN 22 2015
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE MODELS ALL BRING A
FAIRLY SIGNIFICANT SHORTWAVE DOWN INTO THE REGION...BUT STRUGGLE
ON TIMING AND STRENGTH. WARM AIR ADVECTION WILL CONTINUE THROUGH
FRIDAY NIGHT AHEAD OF THE SYSTEM SO THERE WILL BE A CONTINUED
CHANCE FOR SOME MIXED PRECIP WHEN IT MOVES IN. THE ECMWF IS FASTER
THAN THE OTHER DETERMINISTIC MODELS...AND THE 00Z RUN HAS COME IN
FURTHER WEST WITH SIGNIFICANT PRECIP. THIS PUTS IT MORE SIMILAR TO
THE NAM WHICH IS FURTHEREAST WEST WITH DEFORMATION BAND PRECIP AND
IS THE STRONGEST WITH QPF. THE GFS ON THE OTHER HAND...HAS THE
MAIN PRECIP OVER THE FAR EASTERN COUNTIES. WITH HIGH UNCERTAINTY
WILL CONTINUE TO KEEP THE BLENDED SOLUTION...WHICH HAS THE HIGHEST
POPS FOR SATURDAY NIGHT. WITH FAIRLY WARM TEMPS CONTINUING INTO
SATURDAY THERE COULD BE SOME MIXED PRECIP...SO WENT WITH SOME
LIGHT ICING AND A FEW INCHES OF SNOW...MAINLY OVER THE
NORTHEASTERN COUNTIES.
SUNDAY THROUGH WEDNESDAY...LONG WAVE RIDGE ESSENTIALLY REMAINS OVER
WESTERN NORTH AMERICA...PERHAPS RETROGRADES A BIT TROUGH THE
PERIOD. LONG WAVE TROUGH REMAINS OVER EASTERN NORTH AMERICA.
PATTERN INTENSIFIES THROUGH DAY 5 THEN DE AMPLIFIES THEREAFTER.
PATTERN REMAINS THE SAME THROUGH THE PERIOD WITH PROGRESSIVE SHORT
WAVES MOVING THROUGH THE FLOW. SHORT WAVE RIDGE MOVES EAST OVER
THE NORTHERN PLAINS ON WED. THE ECMWF WAS FASTER THAN THE GFS
THROUGH THE PERIOD. GFS AND ECMWF HAVE TRENDED FASTER OVER THE
LAST COUPLE RUNS. WILL PREFER THE ECMWF.
HIGH TEMPS HAVE BEEN INCREASED A DEGREE OR SO FOR SUN AND INCREASED
TWO TO FOUR DEGREES FOR MON THROUGH WED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1147 PM CST WED JAN 21 2015
VFR CONDITIONS EXPECTED THIS PERIOD. CIRRUS WILL INVADE THE REGION
THIS MORNING. LIGHT WINDS WILL BECOME SOUTHERLY THIS MORNING...AND
GUSTY DURING THE DAYTIME HOURS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...TG
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
321 AM CST THU JAN 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CST THU JAN 22 2015
STRATUS SITUATED ACROSS THE AREA THIS MORNING IS EXPECTED TO ERODE
FROM WEST TO EAST THROUGH THE DAY AS 925 MB WINDS TRANSITION TO A
DRIER SOUTHWESTERLY FLOW. ALL MODELS ARE SUPPORTIVE OF THIS...THOUGH
DO LINGER THE CLOUDS IN OUR FAR EAST INTO LATE THIS AFTERNOON.
OTHERWISE...AS WINDS BECOME SOUTHWESTERLY BEHIND EXITING HIGH
PRESSURE TO THE SOUTHEAST...WILL HAVE A MODERATION IN TEMPERATURES
OVER YESTERDAY. THIS WILL PLAY OUT WITH HIGHS INTO THE UPPER 30S TO
NEAR 40 THROUGH MUCH OF THE SOUTH AND WEST...TAPERING BACK TO LOWER
30S FROM EAST CENTRAL SOUTH DAKOTA THROUGH SOUTHWESTERN MINNESOTA
INTO THE SPENCER/STORM LAKE CORRIDOR WHERE CLOUDS MAY HANG A LITTLE
LONGER AND THERMAL PROFILES ARE COOLER.
WARM AIR ADVECTION WILL CONTINUE THROUGH TONIGHT IN THE
SOUTHWESTERLY LOW LEVEL FLOW OUT AHEAD OF AN APPROACHING SURFACE
TROUGH. IN RESPONSE...IT WILL BE A RELATIVELY MILD NIGHT FOR THIS
TIME OF YEAR WITH LOWS MAINLY MID AND UPPER 20S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 311 AM CST THU JAN 22 2015
ABOVE NORMAL TEMPERATURES CONTINUE THROUGHOUT THE MEDIUM AND
EXTENDED PORTIONS OF THE FORECAST. THE ONLY WEATHER CONCERNS WILL BE
FOCUSED ON FRIDAY AND AGAIN SATURDAY NIGHT AS SHORTWAVE ENERGY
PASSES THROUGH THE REGION.
FRIDAY...MODEL CONSENSUS BRINGS A WEAK SHORTWAVE THROUGH THE AREA
DURING THE DAY ON FRIDAY. LOW-LVL WARM ADVECTION WILL BRING THE
THERMAL RIDGE OVERHEAD BY FRIDAY AFTERNOON AHEAD OF A WEAK SFC
TROUGH. BARRING ANY SUBSTANCIAL IMPACT FROM INCREASING MID-UPR
LVL CLOUDS...MOST AREAS SHOULD REACH INTO THE 40S. GFS REMAINS THE
MOST SATURATED SOLUTION AS THIS SHORTWAVE MOVES
THROUGH...PRODUCING LIGHT QPF EAST OF I-29. GIVEN TRAJECTORY AND
PACIFIC MOISTURE FLOW...DRIER SOLUTIONS MAY BE MORE CORRECT.
REGARDLESS...WOULD NOT BE SHOCKED TO HEAR OF A FEW SPRINKLES.
SATURDAY AND SUNDAY...YET ANOTHER SHORTWAVE WILL CREST THE WESTERN
CONUS RIDGE AND TRACK SOUTHEASTWARD THROUGH THE REGION SATURDAY
NIGHT AND SUNDAY. MODELS GUIDANCE HAS DRIFTED A BIT FURTHER APART
TONIGHT WITH TRACK AND INTENSITY OF THE WAVE...BUT GENERALLY
STILL ADVERTISE A WEAK AND SOMEWHAT DISORGANIZED SYSTEM. GIVEN THE 150
KNOT JET STREAK PUSHING THIS WAVE SOUTHEAST...AND LEFT EXIT REGION
OF THAT JET PLANTED NEARBY...LIGHT QPF LATE SATURDAY INTO SUNDAY
SEEMS LIKELY...BUT WHETHER IT IS NEARBY OR JUST NORTH AND EAST OF
THE CWA REMAINS IN QUESTION. GIVEN TEMPERATURES REMAINING ABOVE
NORMAL AS THIS WAVE MOVES THROUGH...A LIGHT MIXTURE OF RAIN/SNOW
WOULD BE EXPECTED.
MONDAY THROUGH WEDNESDAY...THE BROAD WESTERN RIDGE WILL TRY TO
EXPAND EASTWARD EARLY NEXT WEEK PUSHING WARMER AIR INTO THE AREA.
IN FACT...THE WARMEST READINGS MAY ARRIVE BY NEXT TUESDAY AND
WEDNESDAY...BUT THE DEGREE OF WARMING IS IN QUESTION. 925MB TEMPS
OFF THE GFS ARE ONLY IN THE 0 TO +3 RANGE...WHILE THE ECMWF AND EVEN
THE GEM ARE MUCH MUCH WARMER...WITH INCREDIBLE 925MB TEMPS OF +10
TO +13C! IT IS A BIT EARLY TO GET TOO EXCITED ABOUT THE DEGREE OF
POTENTIAL WARMTH ON DAY 7 GIVEN HOW DIFFICULT IT CAN BE TO
MAXIMIZE THIS TYPE OF POTENTIAL GIVEN MODEL VARIABILITY IN THE
EXTENDED PORTIONS OF THE FORECAST. REGARDLESS SOMETHING TO KEEP AN
EYE ON AS WE HEAD INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1054 PM CST WED JAN 21 2015
SWATH OF MVFR CEILINGS ARE EXPECTED TO BEGIN DISSIPATING FROM WEST
TO EAST OVERNIGHT AS LOW LEVEL WINDS SHIFT WESTERLY AND DRIER AIR
BEGINS WORKING INTO THE REGION. STILL A BIT OF UNCERTAINTY WITH
THE NAM HOLDING ONTO LOW CEILINGS INTO THE DAY ON THURSDAY...WHILE
THE GFS AND HRRR SUPPORTS THE DRYING SOLUTION. AM STILL FAVORING
THE DRYING SOLUTION AS SKIES BEGIN CLEARING JUST WEST OF THE
FORECAST AREA. WINDS WILL BE TURNING LIGHT THEN SOUTHWESTERLY AT
THE SURFACE BUT SHOULD REMAIN LESS THAN 15 KT DURING THE DAY
THURSDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...DUX
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1102 PM CST WED JAN 21 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 339 PM CST WED JAN 21 2015
CURRENTLY...STILL HAVE SOME UPPER QG FORCING MOVING SLOWLY
SOUTHEASTWARD THROUGH THE FORECAST AREA. UNTIL THIS GETS TOTALLY
THROUGH...WE ARE RUNNING THE RISK OF AREAS OF LIGHT SNOW OR FLURRIES
LIKELY WINDING DOWN FROM NORTH TO SOUTH THROUGH THE EVENING HOURS.
DUE TO TEMPERATURES HOVERING ONLY A COUPLE OF DEGREES BELOW FREEZING
AT MOST LOCATIONS...SNOWFALL HAS BEEN HAVING TROUBLE STICKING DUE TO
THE LIGHT RATES. OTHERWISE ADDED A MENTION OF PATCHY FOG FOR SOME OF
OUR WESTERN ZONES LATE TONIGHT AND EARLY THURSDAY...MAINLY IN THE
JAMES RIVER VALLEY AND AROUND THE CHAMBERLAIN AREA. THIS IS BECAUSE
THE GFS 925MB RH FIELDS ARE SHOWING A DECREASE IN CLOUDS FOR THAT
AREA AFTER MIDNIGHT AS THE WINDS OFF THE SURFACE BECOME MORE
SOUTHWESTERLY. SOUTHWEST NEBRASKA DOES NOT HAVE A LOT OF STRATUS AT
THIS TIME. THEREFORE IF THEIR STRATUS DOES CLEAR OUT AT THAT TIME OF
DAY...SOME FOG COULD FORM. BUT THE STRATUS FIELD MAY STILL BE
ABUNDANT EAST OF THE JAMES LATE TONIGHT AND EARLY THURSDAY SO LEFT
THE MENTION OF FOG OUT OF THOSE AREAS. THAT SAID...THE 925MB RH DOES
DECREASE THROUGH THE MORNING ON THURSDAY EAST OF THE JAMES
SUGGESTING A DECREASE IN CLOUDS FROM WEST TO EAST. THE NAM LOW LEVEL
RH FIELDS KEEPS EVERYONE SOPPED IN THROUGH THE DAY THURSDAY...AND
THAT WAS NOT FOLLOWED NOTING THE AFOREMENTIONED WIND DIRECTION.
CONCERNING TEMPERATURES...TEMPERED THE FALL IN READINGS THIS EVENING
FROM MANY GUIDANCE VALUES DUE TO CLOUD COVER. OUR LOWS TONIGHT ARE
MOST CLOSELY CORRELATED WITH BIAS CORRECTED MOS VALUES WHICH KEEP
TEMPERATURES PRETTY MILD FOR THIS TIME OF YEAR. WITH A MILD AIR FLOW
ON THURSDAY...ALSO FOLLOWED THE WARMER MOS VALUES FOR THAT PERIOD...
ESPECIALLY THE BIAS CORRECTED VALUES WHICH PLACES HIGHS IN THE MID
30S TO LOWER 40S. THURSDAY SHOULD BE A NICE DAY FOR JANUARY
STANDARDS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 339 PM CST WED JAN 21 2015
FRIDAY INTO THE WEEKEND WILL SEE RIDGING BUILD IN ACROSS THE WESTERN
PART OF THE COUNTRY...PUTTING OUR CWA BACK INTO A NORTHWEST FLOW
PATTERN. ONE WEAK WAVE MAY BRING A FEW SPRINKLES ON FRIDAY.
OTHERWISE WILL SEE LOW LEVEL TEMPERATURES WARM BACK UP...AND GIVEN
RECENT TEMPERATURES...SEE NO REASON NOT TO STAY WITH THE WARMER
GUIDANCE. SOME UNCERTAINTY ON DEGREE OF WARMING EARLY NEXT WEEK WITH
A DECENT SPREAD IN ENSEMBLE GUIDANCE. BUT THE OPERATIONAL ECMWF AND
GFS ARE BOTH WARM...AND GIVEN THE LACK OF SNOW COVER...STAYED WITH
THE WARMER GUIDANCE THROUGH THE PERIOD. THUS FOLLOWING THE WARMER
BIAS CORRECTED GUIDANCE YIELDS HIGHS IN THE 40S FRIDAY INTO EARLY
NEXT WEEK. LOWS WILL BE MILD AS WELL...GENERALLY 20S AND 30S.
MODELS CONTINUE TO BE PRETTY CONSISTENT WITH A WAVE IN THE NORTHWEST
FLOW IMPACTING THE AREA LATER SATURDAY INTO EARLY SUNDAY. MODELS
HAVE TRENDED A BIT FASTER WITH THE SYSTEM AND A BIT WEAKER THOUGH.
BEST FORCING AND MOISTURE END UP REMAINING TO OUR NORTH. THUS QPF
AMOUNTS SEEM TO BE TRENDING DOWN. WITH THE TRACK TO OUR NORTH...LOW
LEVELS SHOULD REMAIN QUITE WARM SATURDAY AFTERNOON AND NIGHT. THUS
THINKING MOST OF THE PRECIPITATION WILL PROBABLY BE LIGHT
RAIN...POSSIBLY MIXED WITH SOME SNOW. BEST CHANCE OF A LIGHT COATING
SEEMS TO BE IN SOUTHWEST MINNESOTA CLOSER TO THE COLDER AIR...BUT
EVEN THERE ANY ACCUMULATION MAY BE DIFFICULT. WILL NEED TO CONTINUE
TO MONITOR TRENDS THOUGH IN CASE THE STRENGTH OR TRACK OF THE SYSTEM
CHANGES. GIVEN THE WEAKER NATURE OF THE SYSTEM...WINDS SATURDAY
NIGHT INTO SUNDAY DO NOT LOOK QUITE AS STRONG...ALTHOUGH WILL STILL
BE BLUSTERY. STILL NOT SEEING ANY SIGNIFICANT PRECIPITATION THREATS
IN THE FORESEEABLE FUTURE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1054 PM CST WED JAN 21 2015
SWATH OF MVFR CEILINGS ARE EXPECTED TO BEGIN DISSIPATING FROM WEST
TO EAST OVERNIGHT AS LOW LEVEL WINDS SHIFT WESTERLY AND DRIER AIR
BEGINS WORKING INTO THE REGION. STILL A BIT OF UNCERTAINTY WITH
THE NAM HOLDING ONTO LOW CEILINGS INTO THE DAY ON THURSDAY...WHILE
THE GFS AND HRRR SUPPORTS THE DRYING SOLUTION. AM STILL FAVORING
THE DRYING SOLUTION AS SKIES BEGIN CLEARING JUST WEST OF THE
FORECAST AREA. WINDS WILL BE TURNING LIGHT THEN SOUTHWESTERLY AT
THE SURFACE BUT SHOULD REMAIN LESS THAN 15 KT DURING THE DAY
THURSDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...CHENARD
AVIATION...
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1002 AM EST THU JAN 22 2015
.UPDATE...MAIN CONCERN FOR THE SHORT TERM PACKAGE TODAY WILL BE
THE TIMING AND ASSOCIATED IMPACTS WITH A COLD FRONT CURRENTLY
FORECAST TO SHIFT THROUGH THE STATE FRIDAY NIGHT INTO SATURDAY
MORNING. FOR THIS AFTERNOON... NOT ANTICIPATING MANY SIGNIFICANT
UPDATES TO THE CURRENT FORECAST PACKAGE. WARM AND MOIST AIR
CONTINUES TO ADVECT INTO WEST CENTRAL FL AS LOW LEVEL FLOW IS
VEERING MORE SOUTHERLY. TEMPS TODAY ARE ON TRACK TO CLIMB A FEW
DEGREES ABOVE AVERAGE. ADDITIONALLY HRRR AND MET THIS MORNING ARE
TRYING TO PICK UP ON THE DEVELOPMENT OF A FEW SHOWERS THIS
AFTERNOON...FAVORING OUR SOUTHERN ZONES. SO WILL KEEP THE 20
POP THIS AFTERNOON FOR A BRIEF SHOWER BUT HAVE TRIMMED OUT THE
NORTHERN ZONES.
&&
.MARINE...FAIRLY BENIGN MARINE CONDITIONS EXPECTED THIS AFTERNOON
AND TONIGHT. HOWEVER...AN AREA OF LOW PRESSURE WILL MOVE OVER THE
NORTHERN WATERS ON FRIDAY WITH WINDS INCREASING TO NEAR ADVISORY
LEVELS. AN ASSOCIATED COLD FRONT WILL PUSH ACROSS THE WATERS
FRIDAY NIGHT WITH INCREASING WINDS AND SEAS IN THE WAKE OF THE
FRONT ON SATURDAY WITH ADVISORY CONDITIONS LIKELY. WINDS AND SEAS
WILL GRADUALLY SUBSIDE SATURDAY NIGHT AND SUNDAY AS HIGH PRESSURE
BUILDS OVER THE WATERS.
&&
.FIRE WEATHER...NO FIRE WEATHER IMPACTS EXPECTED THIS AFTERNOON.
PATCHY MORNING FOG CONTINUES TO BURN OFF ACROSS THE AREA.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 65 75 63 / 10 10 60 60
FMY 83 65 80 67 / 20 10 10 30
GIF 80 64 78 63 / 10 10 50 40
SRQ 78 65 76 65 / 20 10 50 50
BKV 79 62 77 59 / 10 10 70 70
SPG 76 65 73 63 / 20 10 50 60
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/FIRE WEATHER...20/BARRON
MARINE...007/DOUGHERTY
DECISION SUPPORT...24/HUBBARD
AREA FORECAST DISCUSSION
NWS DES MOINES IA
529 AM CST THU JAN 22 2015
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 318 AM CST THU JAN 22 2015
HIGH PRESSURE RIDGE WILL MOVE THROUGH THE AREA TODAY WITH THE
NEXT IN THE SERIES OF FAST MOVING LOW PRESSURE SYSTEMS DROPS
SOUTHEAST THROUGH ONTARIO ON FRIDAY. ANOTHER SYSTEM WILL MOVE OUT
OF NRN ALBERTA AND BRUSH NERN IA SATURDAY NIGHT...AND MOVE INTO
THE MID ATLANTIC SEABOARD BY SUNDAY EVENING. JET STREAM WILL
REMAIN NORTH OF THE AREA THROUGH THE FORECAST PERIOD AS WILL THE
STORM TRACK.
&&
.SHORT TERM /TODAY/...
ISSUED AT 318 AM CST THU JAN 22 2015
MAIN FORECAST CONCERN TODAY DEALT WITH CLOUD COVER AND
TEMPERATURES. THE STRATUS DECK LOOKS TO GRADUALLY THIN OUT AND
DISSIPATE THROUGHOUT THE DAY AND SHOULD SEE MORE SUNSHINE THAN
CLOUD COVER BY AROUND 19Z-20Z. BOTH THE HRRR AND HOPWRF HAVE
CLOUD COVER DISSIPATING B/T 18-21Z THIS AFTERNOON FROM SOUTHWEST
IOWA TO THE NORTHEAST. THIS COINCIDES WITH THE SURFACE HIGH
SHIFTING OVER MUCH OF THE STATE BY MIDDAY AND ADVECTS IN SOME
DRIER AIR AND ALLOWS THE INVERSION TO WEAKEN. THUS...WENT SLIGHTLY
ABOVE PREVIOUS FORECAST OVER THE CENTRAL TO SOUTHWEST WHERE THE
CLOUD COVER SHOULD CLEAR OUT A LITTLE SOONER. WENT CLOSER THE
MAVMOS/SREF FOR MAX TEMPS TODAY.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 318 AM CST THU JAN 22 2015
NOT A LOT OF CHANGE WITH THE IDEAS OF THE MODELS FROM THE PAST FEW
DAYS INTO TODAY. WEATHER SYSTEM OUT OF ALBERTA WILL BRING A CHANCE
FOR MIXED PRECIPITATION OVER THE NORTHEAST...WITH MOSTLY RAIN
OVER THE SOUTHWEST SATURDAY NIGHT INTO SUNDAY. NO REAL COLD AIR
FOLLOWING THE SYSTEM AND WILL SEE MILD LATE JANUARY WEATHER
CONTINUE.
A THIRD IN THE SERIES OF LOW PRESSURE SYSTEMS WILL PASS WELL TO
THE NORTH OF THE AREA FOR MID WEEK...BRINGING IN VERY MILD AIR.
TUE WILL BE QUITE WARM...MAINLY SOUTHWEST...WITH MORE WIDESPREAD
WARMING ON WED. THE ECMWF IS SHOWING THE +16 AT H8 MAKING IT INTO
THE STATE. WENT WARMER THAN MOS AND MORE IN LINE WITH THE ECMWF
OMS FORECASTS FOR WED. ALL SIGNS LOOK GOOD FOR GOOD WARMING OVER
NON-SNOW COVERED AREAS.
THE END OF THE WEEK WILL FEATURE A CHANGE IN THE PATTERN.
INDICATIONS POINT TO A STRONG PUSH OF COLD AIR BY THE
WEEKEND...LIKELY RIVALING THE COLD OUTBREAK WE SAW THE WEEK OF
THE 5TH.
&&
.AVIATION...22/12Z
ISSUED AT 529 AM CST THU JAN 22 2015
IFR CIGS WILL CONTINUE AT MCW THROUGH MUCH OF THE MORNING BUT A
SMALL BREAK IN THE STRATUS DECK MAY SKIRT ACROSS NORTHERN IOWA AND
PROVIDE A SHORT STINT OF MVFR OR EVEN VFR CIGS MID MORNING.
OTHERWISE...FOD/ALO/OTM SHOULD STAY STRATUS OVER THROUGH AT LEAST
THE NEXT TAF ISSUANCE AND POTENTIALLY INTO THE LATE AFTERNOON
HOURS. THINKING THE HIGH MOVING INTO OVER THE SOUTHWEST PART OF
THE STATE WILL PROVIDE ENOUGH WEAKENING TO THE INVERSION AND DRY
AIR INTO THE STATE THE MVFR STRATUS SHOULD DISSIPATE BY AROUND
17Z-18Z AT DSM AND FOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MS JAN 15
SHORT TERM...PODRAZIK
LONG TERM...MS JAN 15
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
725 AM EST THU JAN 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 429 AM EST THU JAN 22 2015
A CLOUDY SKY COVERS ALL OF UPPER MICHIGAN EARLY THIS MORNING...AS
ABUNDANT LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE STRENGTHENING
SUBSIDENCE INVERSION (SEEN ON 00Z KINL SOUNDING) FROM THE HIGH
PRESSURE RIDGE OVER NORTHERN MINNESOTA. RAP ANALYSIS SHOWS A -12C
850MB THERMAL TROUGH SLIDING ACROSS CENTRAL/EASTERN LAKE SUPERIOR
EARLY THIS MORNING (ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
NORTHERN ONTARIO AND BRUSHING NORTHERN LAKE SUPERIOR) AND AIDING
WEAK LAKE EFFECT SNOW SHOWERS IN THE NORTHWEST WIND SNOW BELTS OVER
EASTERN UPPER MICHIGAN. OVERALL THESE ARE FAIRLY WEAK AND DISJOINTED
DUE TO THE MARGINAL DELTA-T VALUES AND WEAK LOW LEVEL LAPSE RATES.
THOSE MARGINAL FEATURES HAVE ALSO LEAD TO OCCASIONAL PERIODS OF
FREEZING DRIZZLE LAST EVENING OVER THE KEWEENAW AND ALSO OVER THE
NORTH CENTRAL THROUGH THE NIGHT. WILL INCLUDE A PATCHY FREEZING
DRIZZLE MENTION FOR THE NEXT COUPLE OF HOURS...BUT EXPECT THERE TO
BE LITTLE TO NO IMPACT WITH THE PRECIP BEING PREDOMINATELY SNOW.
UNDER THE CLOUDY SKIES...TEMPERATURES HAVE BEEN SLOW TO FALL THROUGH
THE NIGHT...WITH 3AM TEMPERATURES STILL IN THE LOWER 20S.
THE HIGH PRESSURE RIDGE OVER MINNESOTA WILL QUICKLY SLIDE EAST
ACROSS UPPER MICHIGAN TODAY...AS THE PARENT HIGH MOVES FROM THE
CENTRAL PLAINS TO THE OHIO RIVER VALLEY. THIS WILL LEAD TO STEADILY
BACKING LOW LEVEL WINDS THIS MORNING AND SHIFT ANY REMAINING LAKE
EFFECT SNOW OVER THE EAST OFFSHORE. THE BIGGEST QUESTION WITH THE
FORECAST TODAY IS WHAT WILL HAPPEN TO THE CLOUDS. MOST MODELS ARE
INDICATING THAT THE LOW CLOUDS WILL SCATTER OUT LATE THIS MORNING
AND INTO THE AFTERNOON. DO HAVE SOME CONCERN WITH THAT DUE TO THE
UPSTREAM OBS STILL INDICATING LOW CLOUDS INTO EASTERN MINNESOTA AND
WESTERN WISCONSIN...ALONG WITH THE STRENGTHENING SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH PRESSURE RIDGE MOVING THROUGH.
BUT WITH THE SOUTHWESTERLY FLOW INCREASING MIXING AND THE MOISTURE
LAYER BECOMING THIN...DID TREND THE FORECAST TOWARDS PARTLY CLOUDY.
THIS SITUATIONS ARE TRICKY...AS SOME AREAS WILL LIKELY CLEAR OUT
COMPLETELY (AIDED BY DOWNSLOPING SOUTHWESTERLY WINDS) WHILE THERE
COULD STILL BE POCKETS OF CLOUDY SKIES. AS THE LOW CLOUDS SCATTER
OUT...HIGH CLOUDS WILL BE THICKENING OVER THE AREA THIS
AFTERNOON/EVENING ASSOCIATED WITH THE APPROACHING CLIPPER SYSTEM.
THUS...WILL GRADUALLY INCREASE THE CLOUDS FROM THE NORTHWEST LATE
THIS AFTERNOON AND CONTINUE THROUGH THE NIGHT. LOWS WILL OCCUR THIS
EVENING AND THEN GRADUALLY WARM OVERNIGHT WITH THE INCREASING
SOUTHWESTERLY FLOW. THAT SOUTHWEST FLOW...WHICH WILL PRODUCE GALES
OVER WESTERN/CENTRAL LAKE SUPERIOR...IS EXPECTED TO LEAD TO GUSTY
CONDITIONS DEVELOPING OVER THE FAR WEST THIS AFTERNOON AND ACROSS
THE AREA TONIGHT. THINK THE STRONGEST GUSTS WILL REMAIN TOWARDS ISLE
ROYALE WHERE THE BEST PRESSURE FALLS ARE LOCATED...BUT STILL SHOULD
SEE SOME GUSTS TO 20-25KTS (AND 30KTS OVER THE KEWEENAW) TONIGHT.
AS THE COLD FRONT ASSOCIATED WITH THE CLIPPER SYSTEM APPROACHES LAKE
SUPERIOR TONIGHT...SHOULD SEE PRECIPITATION DROPPING SOUTHEAST
ACROSS WESTERN/CENTRAL LAKE SUPERIOR OVERNIGHT. SHOULD SEE IT
IMPACTING THE KEWEENAW PENINSULA BETWEEN 9-12Z. HAVE KEPT
PRECIPITATION AS SNOW FOR MOST LAND LOCATIONS THROUGH 12Z...BUT WITH
THE NAM INDICATING A WARM NOSE MOVING INTO WESTERN LAKE SUPERIOR
TOWARDS 12Z...DID ADD A MENTION OF FREEZING RAIN AND SLEET TO THAT
AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 524 AM EST THU JAN 22 2015
A PERSISTENT RIDGE OVER THE WRN CONUS WILL MAINTAIN NW MID/UPPER
LEVEL FLOW ACROSS THE NRN GREAT LAKES THROUGH THE MIDDLE OF NEXT
WEEK. THIS WILL BRING A SERIES OF CLIPPERS INTO THE REGION. IT
APPEARS AT THIS TIME ANY LES FROM THESE CLIPPERS WOULD BE LIGHT AS
ONLY MARGINAL INSTABILITY IS EXPECTED WITH THE COLDEST AIR
REMAINING OVER NE CANADA.
FRIDAY...MODELS FCST QVECTOR CONV AHEAD OF A SHORTWAVE TROUGH ALONG
WITH 280K-290K ISENTROPIC LIFT SHOULD BE STRONG ENOUGH TO SQUEEZE
OUT SOME LIGHT PCPN INTO PORTIONS OF UPPER MI. THERE IS STILL SOME
UNCERTAINTY WITH THE PCPN AMOUNTS/PLACEMENT. HOWEVER...THE STRONGER
FORCING IS EXPECTED TO MOVE THROUGH DURING THE MORNING WITH DRYING
DURING THE AFTERNOON. THE NAM...WHICH OFTEN PERFORMS BETTER WITH
DEVELOPING WARM LAYERS ALOFT...SUGGESTS THAT THE PCPN OVER THE WEST
HALF COULD BE MIXED WITH FREEZING RAIN OR SLEET AS THE MAX TEMP
ALOFT CLIMBS TO AROUND 3C(NEAR 900 MB). THE POSITION OF THE WARM
NOSE WOULD BRING THE BEST CHANCE FOR ANY ICING OVER MAINLY JUST THE
FAR WEST. OTHERWISE...TEMPS WILL CLIMB WELL ABOVE NORMAL WITH MAX
READINGS INTO THE MID 30S.
FRI NIGHT... COLDER AIR WILL ONLY GRADUALLY MOVE IN FRI NIGHT WITH
NW WINDS BEHIND A SFC TROUGH AS 850 MB TEMPS DROP TO -6C TO -8C BY
12Z/SAT. SOME LIGHT LAKE ENHANCED SNOW IS POSSIBLE FOR NW FLOW
FAVORED LOCATIONS AS A WEAK SHORTWAVE MOVES THROUGH WITH DEEPER
MOISTURE OVER THE AREA. OTHERWISE...WRLY FLOW OF PACIFIC AIR BEHIND
THE SFC TROUGH WILL KEEP TEMPS FROM DROPPING OFF MUCH WITH MANY
LOCATIONS NOT DROPPING MUCH BELOW 30F...ESPECIALLY FOR DOWNSLOPE
FLOW LOCATIONS.
SAT...MARGINALLY COLD AIR WITH 850 MB TEMPS FALLING TO -10C TO
-12C WILL MOVE IN AS A RIDGE BUILDS INTO THE WRN LAKES. DIMINISHING
LOW LEVEL WINDS BECOMING MORE ANTICYCLONIC AND NRLY WITH TIME WILL
ALSO LIMIT POTENTIAL FOR LES ACCUMULATIONS CONSISTENT WITH ONLY
CHANCE POPS.
SAT NIGHT AND SUN...THERE IS STILL SOME MODEL UNCERTAINTY WITH THE
TRACK OF THE NEXT CLIPPER SYSTEM. THE ECMWF REMAINS FARTHEST TO THE
WEST AND SOUTH WITH LITTLE PCPN INTO UPPER MICHIGAN WHILE THE
CANADIAN BRINGS THE HEAVIER PCPN THROUGH THE CWA. SOME AREAS IN THE
REGION COULD SEE SNOWFALL INTO THE 1 TO 4 INCH RANGE WITH THE SYSTEM.
THE GFS REPRESENTS A COMPROMISE KEEPING THEPCPN OVER WEST UPPER
MICHIGAN. WILL CONTINUE ALONG WITH CONSENSUS FCST WHICH KEEPS CHANCE
POPS ACROSS THE WEST.
MON INTO WED...ANOTHER CLIPPER SYSTEM IS EXPECTED TO MOVE INTO THE
REGION BY LATE MON OR MON NIGHT BUT THE MODELS HAVE TRENDED WEAKER
WITH THIS SHRTWV WITH ONLY LIGHT PCPN REMAINING WEST OF UPPER MI.
SFC RIDGING INTO THE AREA WITH LIGHT WINDS WILL ALSO NOT BE
FAVORABLE FOR LES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 635 AM EST THU JAN 22 2015
MVFR CLOUDS WILL CONTINUE THROUGH THE MORNING FOR THE TAF
SITES...AS A HIGH PRESSURE RIDGE QUICKLY SHIFTS EAST ACROSS UPPER
MICHIGAN. BEHIND THE RIDGE...WINDS WILL BACK TO THE SOUTHWEST AND
GRADUALLY INCREASE THIS AFTERNOON AND EVENING AHEAD OF A CLIPPER
SYSTEM THAT WILL AFFECT KCMX LATE TONIGHT AND THE OTHER SITES ON
FRIDAY. AS THE WINDS BACK TO THE SOUTHWEST AND THE CLOUDS BECOME
PINCHED BY DRY AIR ALOFT...EXPECT CLOUDS TO BEGIN SCATTERING OUT
THIS AFTERNOON. THIS SHOULD OCCUR FIRST AT KIWD/KSAW WITH THE
DOWNSLOPING FLOW AND THEN AT KCMX. WITH THE ABUNDANT MOISTURE TO
THE SOUTHWEST OF THE AREA...THERE IS THE POTENTIAL THE MVFR CLOUDS
BECOME TRAPPED BELOW THE INVERSION AND DELAY THE DEPARTURE A FEW
HOURS.
FOR TONIGHT...EXPECT GUSTY SOUTHWEST WINDS AND WITH THE STRONG
WINDS JUST ABOVE THE SURFACE...DID INCLUDE WIND SHEAR FOR ALL THREE
SITES. SNOW FROM THE CLIPPER SYSTEM WILL ARRIVE LATE TONIGHT AT
KCMX AND HAVE BROUGHT CONDITIONS BACK DOWN TO MVFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EST THU JAN 22 2015
A HIGH PRESSURE RIDGE WILL QUICKLY SLIDE EAST ACROSS THE UPPER
GREAT LAKES REGION THIS MORNING...STEADILY BACKING WINDS TO THE
SOUTHWEST. AS THE PRESSURE GRADIENT TIGHTENS THIS AFTERNOON AND
TONIGHT AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH NORTHERN
MANITOBA AND NORTHERN ONTARIO...EXPECT SOUTHWESTERLY GALES OF
35-40KTS OVER PORTIONS OF WESTERN AND CENTRAL UPPER MICHIGAN. BASED
OFF THE STRENGTH OF THE WINDS JUST ABOVE THE SURFACE...WOULDN/T BE
SURPRISED TO SEE SOME 45KT GUSTS AT THE HIGHER PLATFORMS AROUND
ISLE ROYALE. THE GALE WARNING THAT IS IN PLACE LOOKS TO BE IN DECENT
SHAPE...ALTHOUGH DID EXPAND IT SOUTHWEST TO LSZ162. A COLD FRONT
ASSOCIATED WITH THE LOW WILL SWEEP SOUTHEAST ACROSS LAKE SUPERIOR
ON FRIDAY...SHIFTING THE WINDS TO THE NORTHWEST AND BRINGING AN END
TO THE GALES. BEHIND THE FRONT...EXPECT WINDS TO 25-30KTS BEFORE
SHIFTING MORE NORTHERLY BEHIND A SECONDARY TROUGH ON MOVING ACROSS
LAKE SUPERIOR ON SATURDAY. WINDS WILL DIMINISH BEHIND THE SECONDARY
TROUGH AS A HIGH PRESSURE RIDGE SHIFTS SOUTH INTO THE AREA
SATURDAY NIGHT. ANOTHER CLIPPER SYSTEM WILL MOVE OUT OF CANADA AND
THROUGH THE UPPER MISSISSIPPI VALLEY ON SATURDAY NIGHT AND THEN
SLIDE THROUGH WISCONSIN SUNDAY MORNING. THIS WILL KEEP WINDS UP TO
20KTS OUT OF THE NORTH-NORTHEAST. ANOTHER RIDGE WILL BUILD IN
BEHIND THIS CLIPPER AND KEEP WINDS 15KTS OR BELOW SUNDAY NIGHT INTO
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 PM EST /5 PM CST/ THIS EVENING TO 9 AM EST
/8 AM CST/ FRIDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
636 AM EST THU JAN 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 429 AM EST THU JAN 22 2015
A CLOUDY SKY COVERS ALL OF UPPER MICHIGAN EARLY THIS MORNING...AS
ABUNDANT LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE STRENGTHENING
SUBSIDENCE INVERSION (SEEN ON 00Z KINL SOUNDING) FROM THE HIGH
PRESSURE RIDGE OVER NORTHERN MINNESOTA. RAP ANALYSIS SHOWS A -12C
850MB THERMAL TROUGH SLIDING ACROSS CENTRAL/EASTERN LAKE SUPERIOR
EARLY THIS MORNING (ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
NORTHERN ONTARIO AND BRUSHING NORTHERN LAKE SUPERIOR) AND AIDING
WEAK LAKE EFFECT SNOW SHOWERS IN THE NORTHWEST WIND SNOW BELTS OVER
EASTERN UPPER MICHIGAN. OVERALL THESE ARE FAIRLY WEAK AND DISJOINTED
DUE TO THE MARGINAL DELTA-T VALUES AND WEAK LOW LEVEL LAPSE RATES.
THOSE MARGINAL FEATURES HAVE ALSO LEAD TO OCCASIONAL PERIODS OF
FREEZING DRIZZLE LAST EVENING OVER THE KEWEENAW AND ALSO OVER THE
NORTH CENTRAL THROUGH THE NIGHT. WILL INCLUDE A PATCHY FREEZING
DRIZZLE MENTION FOR THE NEXT COUPLE OF HOURS...BUT EXPECT THERE TO
BE LITTLE TO NO IMPACT WITH THE PRECIP BEING PREDOMINATELY SNOW.
UNDER THE CLOUDY SKIES...TEMPERATURES HAVE BEEN SLOW TO FALL THROUGH
THE NIGHT...WITH 3AM TEMPERATURES STILL IN THE LOWER 20S.
THE HIGH PRESSURE RIDGE OVER MINNESOTA WILL QUICKLY SLIDE EAST
ACROSS UPPER MICHIGAN TODAY...AS THE PARENT HIGH MOVES FROM THE
CENTRAL PLAINS TO THE OHIO RIVER VALLEY. THIS WILL LEAD TO STEADILY
BACKING LOW LEVEL WINDS THIS MORNING AND SHIFT ANY REMAINING LAKE
EFFECT SNOW OVER THE EAST OFFSHORE. THE BIGGEST QUESTION WITH THE
FORECAST TODAY IS WHAT WILL HAPPEN TO THE CLOUDS. MOST MODELS ARE
INDICATING THAT THE LOW CLOUDS WILL SCATTER OUT LATE THIS MORNING
AND INTO THE AFTERNOON. DO HAVE SOME CONCERN WITH THAT DUE TO THE
UPSTREAM OBS STILL INDICATING LOW CLOUDS INTO EASTERN MINNESOTA AND
WESTERN WISCONSIN...ALONG WITH THE STRENGTHENING SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH PRESSURE RIDGE MOVING THROUGH.
BUT WITH THE SOUTHWESTERLY FLOW INCREASING MIXING AND THE MOISTURE
LAYER BECOMING THIN...DID TREND THE FORECAST TOWARDS PARTLY CLOUDY.
THIS SITUATIONS ARE TRICKY...AS SOME AREAS WILL LIKELY CLEAR OUT
COMPLETELY (AIDED BY DOWNSLOPING SOUTHWESTERLY WINDS) WHILE THERE
COULD STILL BE POCKETS OF CLOUDY SKIES. AS THE LOW CLOUDS SCATTER
OUT...HIGH CLOUDS WILL BE THICKENING OVER THE AREA THIS
AFTERNOON/EVENING ASSOCIATED WITH THE APPROACHING CLIPPER SYSTEM.
THUS...WILL GRADUALLY INCREASE THE CLOUDS FROM THE NORTHWEST LATE
THIS AFTERNOON AND CONTINUE THROUGH THE NIGHT. LOWS WILL OCCUR THIS
EVENING AND THEN GRADUALLY WARM OVERNIGHT WITH THE INCREASING
SOUTHWESTERLY FLOW. THAT SOUTHWEST FLOW...WHICH WILL PRODUCE GALES
OVER WESTERN/CENTRAL LAKE SUPERIOR...IS EXPECTED TO LEAD TO GUSTY
CONDITIONS DEVELOPING OVER THE FAR WEST THIS AFTERNOON AND ACROSS
THE AREA TONIGHT. THINK THE STRONGEST GUSTS WILL REMAIN TOWARDS ISLE
ROYALE WHERE THE BEST PRESSURE FALLS ARE LOCATED...BUT STILL SHOULD
SEE SOME GUSTS TO 20-25KTS (AND 30KTS OVER THE KEWEENAW) TONIGHT.
AS THE COLD FRONT ASSOCIATED WITH THE CLIPPER SYSTEM APPROACHES LAKE
SUPERIOR TONIGHT...SHOULD SEE PRECIPITATION DROPPING SOUTHEAST
ACROSS WESTERN/CENTRAL LAKE SUPERIOR OVERNIGHT. SHOULD SEE IT
IMPACTING THE KEWEENAW PENINSULA BETWEEN 9-12Z. HAVE KEPT
PRECIPITATION AS SNOW FOR MOST LAND LOCATIONS THROUGH 12Z...BUT WITH
THE NAM INDICATING A WARM NOSE MOVING INTO WESTERN LAKE SUPERIOR
TOWARDS 12Z...DID ADD A MENTION OF FREEZING RAIN AND SLEET TO THAT
AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 524 AM EST THU JAN 22 2015
A PERSISTENT RIDGE OVER THE WRN CONUS WILL MAINTAIN NW MID/UPPER
LEVEL FLOW ACROSS THE NRN GREAT LAKES THROUGH THE MIDDLE OF NEXT
WEEK. THIS WILL BRING A SERIES OF CLIPPERS INTO THE REGION. IT
APPEARS AT THIS TIME ANY LES FROM THESE CLIPPERS WOULD BE LIGHT AS
ONLY MARGINAL INSTABILITY IS EXPECTED WITH THE COLDEST AIR
REMAINING OVER NE CANADA.
FRIDAY...MODELS FCST QVECTOR CONV AHEAD OF A SHORTWAVE TROUGH ALONG
WITH 280K-290K ISENTROPIC LIFT SHOULD BE STRONG ENOUGH TO SQUEEZE
OUT SOME LIGHT PCPN INTO PORTIONS OF UPPER MI. THERE IS STILL SOME
UNCERTAINTY WITH THE PCPN AMOUNTS/PLACEMENT. HOWEVER...THE STRONGER
FORCING IS EXPECTED TO MOVE THROUGH DURING THE MORNING WITH DRYING
DURING THE AFTERNOON. THE NAM...WHICH OFTEN PERFORMS BETTER WITH
DEVELOPING WARM LAYERS ALOFT...SUGGESTS THAT THE PCPN OVER THE WEST
HALF COULD BE MIXED WITH FREEZING RAIN OR SLEET AS THE MAX TEMP
ALOFT CLIMBS TO AROUND 3C(NEAR 900 MB). THE POSITION OF THE WARM
NOSE WOULD BRING THE BEST CHANCE FOR ANY ICING OVER MAINLY JUST THE
FAR WEST. OTHERWISE...TEMPS WILL CLIMB WELL ABOVE NORMAL WITH MAX
READINGS INTO THE MID 30S.
FRI NIGHT... COLDER AIR WILL ONLY GRADUALLY MOVE IN FRI NIGHT WITH
NW WINDS BEHIND A SFC TROUGH AS 850 MB TEMPS DROP TO -6C TO -8C BY
12Z/SAT. SOME LIGHT LAKE ENHANCED SNOW IS POSSIBLE FOR NW FLOW
FAVORED LOCATIONS AS A WEAK SHORTWAVE MOVES THROUGH WITH DEEPER
MOISTURE OVER THE AREA. OTHERWISE...WRLY FLOW OF PACIFIC AIR BEHIND
THE SFC TROUGH WILL KEEP TEMPS FROM DROPPING OFF MUCH WITH MANY
LOCATIONS NOT DROPPING MUCH BELOW 30F...ESPECIALLY FOR DOWNSLOPE
FLOW LOCATIONS.
SAT...MARGINALLY COLD AIR WITH 850 MB TEMPS FALLING TO -10C TO
-12C WILL MOVE IN AS A RIDGE BUILDS INTO THE WRN LAKES. DIMINISHING
LOW LEVEL WINDS BECOMING MORE ANTICYCLONIC AND NRLY WITH TIME WILL
ALSO LIMIT POTENTIAL FOR LES ACCUMULATIONS CONSISTENT WITH ONLY
CHANCE POPS.
SAT NIGHT AND SUN...THERE IS STILL SOME MODEL UNCERTAINTY WITH THE
TRACK OF THE NEXT CLIPPER SYSTEM. THE ECMWF REMAINS FARTHEST TO THE
WEST AND SOUTH WITH LITTLE PCPN INTO UPPER MICHIGAN WHILE THE
CANADIAN BRINGS THE HEAVIER PCPN THROUGH THE CWA. SOME AREAS IN THE
REGION COULD SEE SNOWFALL INTO THE 1 TO 4 INCH RANGE WITH THE SYSTEM.
THE GFS REPRESENTS A COMPROMISE KEEPING THEPCPN OVER WEST UPPER
MICHIGAN. WILL CONTINUE ALONG WITH CONSENSUS FCST WHICH KEEPS CHANCE
POPS ACROSS THE WEST.
MON INTO WED...ANOTHER CLIPPER SYSTEM IS EXPECTED TO MOVE INTO THE
REGION BY LATE MON OR MON NIGHT BUT THE MODELS HAVE TRENDED WEAKER
WITH THIS SHRTWV WITH ONLY LIGHT PCPN REMAINING WEST OF UPPER MI.
SFC RIDGING INTO THE AREA WITH LIGHT WINDS WILL ALSO NOT BE
FAVORABLE FOR LES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 635 AM EST THU JAN 22 2015
MVFR CLOUDS WILL CONTINUE THROUGH THE MORNING FOR THE TAF
SITES...AS A HIGH PRESSURE RIDGE QUICKLY SHIFTS EAST ACROSS UPPER
MICHIGAN. BEHIND THE RIDGE...WINDS WILL BACK TO THE SOUTHWEST AND
GRADUALLY INCREASE THIS AFTERNOON AND EVENING AHEAD OF A CLIPPER
SYSTEM THAT WILL AFFECT KCMX LATE TONIGHT AND THE OTHER SITES ON
FRIDAY. AS THE WINDS BACK TO THE SOUTHWEST AND THE CLOUDS BECOME
PINCHED BY DRY AIR ALOFT...EXPECT CLOUDS TO BEGIN SCATTERING OUT
THIS AFTERNOON. THIS SHOULD OCCUR FIRST AT KIWD/KSAW WITH THE
DOWNSLOPING FLOW AND THEN AT KCMX. WITH THE ABUNDANT MOISTURE TO
THE SOUTHWEST OF THE AREA...THERE IS THE POTENTIAL THE MVFR CLOUDS
BECOME TRAPPED BELOW THE INVERSION AND DELAY THE DEPARTURE A FEW
HOURS.
FOR TONIGHT...EXPECT GUSTY SOUTHWEST WINDS AND WITH THE STRONG
WINDS JUST ABOVE THE SURFACE...DID INCLUDE WIND SHEAR FOR ALL THREE
SITES. SNOW FROM THE CLIPPER SYSTEM WILL ARRIVE LATE TONIGHT AT
KCMX AND HAVE BROUGHT CONDITIONS BACK DOWN TO MVFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EST THU JAN 22 2015
A HIGH PRESSURE RIDGE WILL QUICKLY SLIDE EAST ACROSS THE UPPER
GREAT LAKES REGION THIS MORNING...STEADILY BACKING WINDS TO THE
SOUTHWEST. AS THE PRESSURE GRADIENT TIGHTENS THIS AFTERNOON AND
TONIGHT AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH NORTHERN
MANITOBA AND NORTHERN ONTARIO...EXPECT SOUTHWESTERLY GALES OF
35-40KTS OVER PORTIONS OF WESTERN AND CENTRAL UPPER MICHIGAN. BASED
OFF THE STRENGTH OF THE WINDS JUST ABOVE THE SURFACE...WOULDN/T BE
SURPRISED TO SEE SOME 45KT GUSTS AT THE HIGHER PLATFORMS AROUND
ISLE ROYALE. THE GALE WARNING THAT IS IN PLACE LOOKS TO BE IN DECENT
SHAPE...ALTHOUGH DID EXPAND IT SOUTHWEST TO LSZ162. A COLD FRONT
ASSOCIATED WITH THE LOW WILL SWEEP SOUTHEAST ACROSS LAKE SUPERIOR
ON FRIDAY...SHIFTING THE WINDS TO THE NORTHWEST AND BRINGING AN END
TO THE GALES. BEHIND THE FRONT...EXPECT WINDS TO 25-30KTS BEFORE
SHIFTING MORE NORTHERLY BEHIND A SECONDARY TROUGH ON MOVING ACROSS
LAKE SUPERIOR ON SATURDAY. WINDS WILL DIMINISH BEHIND THE SECONDARY
TROUGH AS A HIGH PRESSURE RIDGE SHIFTS SOUTH INTO THE AREA
SATURDAY NIGHT. ANOTHER CLIPPER SYSTEM WILL MOVE OUT OF CANADA AND
THROUGH THE UPPER MISSISSIPPI VALLEY ON SATURDAY NIGHT AND THEN
SLIDE THROUGH WISCONSIN SUNDAY MORNING. THIS WILL KEEP WINDS UP TO
20KTS OUT OF THE NORTH-NORTHEAST. ANOTHER RIDGE WILL BUILD IN
BEHIND THIS CLIPPER AND KEEP WINDS 15KTS OR BELOW SUNDAY NIGHT INTO
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 PM THIS EVENING TO 9 AM EST FRIDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
525 AM EST THU JAN 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 429 AM EST THU JAN 22 2015
A CLOUDY SKY COVERS ALL OF UPPER MICHIGAN EARLY THIS MORNING...AS
ABUNDANT LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE STRENGTHENING
SUBSIDENCE INVERSION (SEEN ON 00Z KINL SOUNDING) FROM THE HIGH
PRESSURE RIDGE OVER NORTHERN MINNESOTA. RAP ANALYSIS SHOWS A -12C
850MB THERMAL TROUGH SLIDING ACROSS CENTRAL/EASTERN LAKE SUPERIOR
EARLY THIS MORNING (ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
NORTHERN ONTARIO AND BRUSHING NORTHERN LAKE SUPERIOR) AND AIDING
WEAK LAKE EFFECT SNOW SHOWERS IN THE NORTHWEST WIND SNOW BELTS OVER
EASTERN UPPER MICHIGAN. OVERALL THESE ARE FAIRLY WEAK AND DISJOINTED
DUE TO THE MARGINAL DELTA-T VALUES AND WEAK LOW LEVEL LAPSE RATES.
THOSE MARGINAL FEATURES HAVE ALSO LEAD TO OCCASIONAL PERIODS OF
FREEZING DRIZZLE LAST EVENING OVER THE KEWEENAW AND ALSO OVER THE
NORTH CENTRAL THROUGH THE NIGHT. WILL INCLUDE A PATCHY FREEZING
DRIZZLE MENTION FOR THE NEXT COUPLE OF HOURS...BUT EXPECT THERE TO
BE LITTLE TO NO IMPACT WITH THE PRECIP BEING PREDOMINATELY SNOW.
UNDER THE CLOUDY SKIES...TEMPERATURES HAVE BEEN SLOW TO FALL THROUGH
THE NIGHT...WITH 3AM TEMPERATURES STILL IN THE LOWER 20S.
THE HIGH PRESSURE RIDGE OVER MINNESOTA WILL QUICKLY SLIDE EAST
ACROSS UPPER MICHIGAN TODAY...AS THE PARENT HIGH MOVES FROM THE
CENTRAL PLAINS TO THE OHIO RIVER VALLEY. THIS WILL LEAD TO STEADILY
BACKING LOW LEVEL WINDS THIS MORNING AND SHIFT ANY REMAINING LAKE
EFFECT SNOW OVER THE EAST OFFSHORE. THE BIGGEST QUESTION WITH THE
FORECAST TODAY IS WHAT WILL HAPPEN TO THE CLOUDS. MOST MODELS ARE
INDICATING THAT THE LOW CLOUDS WILL SCATTER OUT LATE THIS MORNING
AND INTO THE AFTERNOON. DO HAVE SOME CONCERN WITH THAT DUE TO THE
UPSTREAM OBS STILL INDICATING LOW CLOUDS INTO EASTERN MINNESOTA AND
WESTERN WISCONSIN...ALONG WITH THE STRENGTHENING SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH PRESSURE RIDGE MOVING THROUGH.
BUT WITH THE SOUTHWESTERLY FLOW INCREASING MIXING AND THE MOISTURE
LAYER BECOMING THIN...DID TREND THE FORECAST TOWARDS PARTLY CLOUDY.
THIS SITUATIONS ARE TRICKY...AS SOME AREAS WILL LIKELY CLEAR OUT
COMPLETELY (AIDED BY DOWNSLOPING SOUTHWESTERLY WINDS) WHILE THERE
COULD STILL BE POCKETS OF CLOUDY SKIES. AS THE LOW CLOUDS SCATTER
OUT...HIGH CLOUDS WILL BE THICKENING OVER THE AREA THIS
AFTERNOON/EVENING ASSOCIATED WITH THE APPROACHING CLIPPER SYSTEM.
THUS...WILL GRADUALLY INCREASE THE CLOUDS FROM THE NORTHWEST LATE
THIS AFTERNOON AND CONTINUE THROUGH THE NIGHT. LOWS WILL OCCUR THIS
EVENING AND THEN GRADUALLY WARM OVERNIGHT WITH THE INCREASING
SOUTHWESTERLY FLOW. THAT SOUTHWEST FLOW...WHICH WILL PRODUCE GALES
OVER WESTERN/CENTRAL LAKE SUPERIOR...IS EXPECTED TO LEAD TO GUSTY
CONDITIONS DEVELOPING OVER THE FAR WEST THIS AFTERNOON AND ACROSS
THE AREA TONIGHT. THINK THE STRONGEST GUSTS WILL REMAIN TOWARDS ISLE
ROYALE WHERE THE BEST PRESSURE FALLS ARE LOCATED...BUT STILL SHOULD
SEE SOME GUSTS TO 20-25KTS (AND 30KTS OVER THE KEWEENAW) TONIGHT.
AS THE COLD FRONT ASSOCIATED WITH THE CLIPPER SYSTEM APPROACHES LAKE
SUPERIOR TONIGHT...SHOULD SEE PRECIPITATION DROPPING SOUTHEAST
ACROSS WESTERN/CENTRAL LAKE SUPERIOR OVERNIGHT. SHOULD SEE IT
IMPACTING THE KEWEENAW PENINSULA BETWEEN 9-12Z. HAVE KEPT
PRECIPITATION AS SNOW FOR MOST LAND LOCATIONS THROUGH 12Z...BUT WITH
THE NAM INDICATING A WARM NOSE MOVING INTO WESTERN LAKE SUPERIOR
TOWARDS 12Z...DID ADD A MENTION OF FREEZING RAIN AND SLEET TO THAT
AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 524 AM EST THU JAN 22 2015
A PERSISTENT RIDGE OVER THE WRN CONUS WILL MAINTAIN NW MID/UPPER
LEVEL FLOW ACROSS THE NRN GREAT LAKES THROUGH THE MIDDLE OF NEXT
WEEK. THIS WILL BRING A SERIES OF CLIPPERS INTO THE REGION. IT
APPEARS AT THIS TIME ANY LES FROM THESE CLIPPERS WOULD BE LIGHT AS
ONLY MARGINAL INSTABILITY IS EXPECTED WITH THE COLDEST AIR
REMAINING OVER NE CANADA.
FRIDAY...MODELS FCST QVECTOR CONV AHEAD OF A SHORTWAVE TROUGH ALONG
WITH 280K-290K ISENTROPIC LIFT SHOULD BE STRONG ENOUGH TO SQUEEZE
OUT SOME LIGHT PCPN INTO PORTIONS OF UPPER MI. THERE IS STILL SOME
UNCERTAINTY WITH THE PCPN AMOUNTS/PLACEMENT. HOWEVER...THE STRONGER
FORCING IS EXPECTED TO MOVE THROUGH DURING THE MORNING WITH DRYING
DURING THE AFTERNOON. THE NAM...WHICH OFTEN PERFORMS BETTER WITH
DEVELOPING WARM LAYERS ALOFT...SUGGESTS THAT THE PCPN OVER THE WEST
HALF COULD BE MIXED WITH FREEZING RAIN OR SLEET AS THE MAX TEMP
ALOFT CLIMBS TO AROUND 3C(NEAR 900 MB). THE POSITION OF THE WARM
NOSE WOULD BRING THE BEST CHANCE FOR ANY ICING OVER MAINLY JUST THE
FAR WEST. OTHERWISE...TEMPS WILL CLIMB WELL ABOVE NORMAL WITH MAX
READINGS INTO THE MID 30S.
FRI NIGHT... COLDER AIR WILL ONLY GRADUALLY MOVE IN FRI NIGHT WITH
NW WINDS BEHIND A SFC TROUGH AS 850 MB TEMPS DROP TO -6C TO -8C BY
12Z/SAT. SOME LIGHT LAKE ENHANCED SNOW IS POSSIBLE FOR NW FLOW
FAVORED LOCATIONS AS A WEAK SHORTWAVE MOVES THROUGH WITH DEEPER
MOISTURE OVER THE AREA. OTHERWISE...WRLY FLOW OF PACIFIC AIR BEHIND
THE SFC TROUGH WILL KEEP TEMPS FROM DROPPING OFF MUCH WITH MANY
LOCATIONS NOT DROPPING MUCH BELOW 30F...ESPECIALLY FOR DOWNSLOPE
FLOW LOCATIONS.
SAT...MARGINALLY COLD AIR WITH 850 MB TEMPS FALLING TO -10C TO
-12C WILL MOVE IN AS A RIDGE BUILDS INTO THE WRN LAKES. DIMINISHING
LOW LEVEL WINDS BECOMING MORE ANTICYCLONIC AND NRLY WITH TIME WILL
ALSO LIMIT POTENTIAL FOR LES ACCUMULATIONS CONSISTENT WITH ONLY
CHANCE POPS.
SAT NIGHT AND SUN...THERE IS STILL SOME MODEL UNCERTAINTY WITH THE
TRACK OF THE NEXT CLIPPER SYSTEM. THE ECMWF REMAINS FARTHEST TO THE
WEST AND SOUTH WITH LITTLE PCPN INTO UPPER MICHIGAN WHILE THE
CANADIAN BRINGS THE HEAVIER PCPN THROUGH THE CWA. SOME AREAS IN THE
REGION COULD SEE SNOWFALL INTO THE 1 TO 4 INCH RANGE WITH THE SYSTEM.
THE GFS REPRESENTS A COMPROMISE KEEPING THEPCPN OVER WEST UPPER
MICHIGAN. WILL CONTINUE ALONG WITH CONSENSUS FCST WHICH KEEPS CHANCE
POPS ACROSS THE WEST.
MON INTO WED...ANOTHER CLIPPER SYSTEM IS EXPECTED TO MOVE INTO THE
REGION BY LATE MON OR MON NIGHT BUT THE MODELS HAVE TRENDED WEAKER
WITH THIS SHRTWV WITH ONLY LIGHT PCPN REMAINING WEST OF UPPER MI.
SFC RIDGING INTO THE AREA WITH LIGHT WINDS WILL ALSO NOT BE
FAVORABLE FOR LES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1157 PM EST WED JAN 21 2015
CURRENT WIDESPREAD COVERAGE OF MVFR CIGS ACROSS THE AREA AND LIGHT
NW FLOW OFF LAKE SUPERIOR SUGGEST MVFR CIGS WILL PREVAIL AT
KIWD/KCMX/KSAW THRU THE NIGHT. EXPECT SOME -SHSN/FLURRIES AS
WELL...BUT VIS WILL REMAIN VFR. PASSAGE OF HIGH PRES RIDGE TODAY
WILL RESULT IN WINDS BACKING TO THE SW...PUSHING MVFR CIGS OUT AND
BRINGING A RETURN OF VFR TO ALL TERMINALS LATE MORNING/EARLY AFTN.
TIGHTENING PRES GRADIENT WILL LEAD TO INCREASING SW WINDS IN THE
AFTN/EVENING. DEPENDING ON DEGREE THAT WINDS REMAIN DECOUPLED...LLWS
WILL BE POSSIBLE IN THE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EST THU JAN 22 2015
A HIGH PRESSURE RIDGE WILL QUICKLY SLIDE EAST ACROSS THE UPPER
GREAT LAKES REGION THIS MORNING...STEADILY BACKING WINDS TO THE
SOUTHWEST. AS THE PRESSURE GRADIENT TIGHTENS THIS AFTERNOON AND
TONIGHT AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH NORTHERN
MANITOBA AND NORTHERN ONTARIO...EXPECT SOUTHWESTERLY GALES OF
35-40KTS OVER PORTIONS OF WESTERN AND CENTRAL UPPER MICHIGAN. BASED
OFF THE STRENGTH OF THE WINDS JUST ABOVE THE SURFACE...WOULDN/T BE
SURPRISED TO SEE SOME 45KT GUSTS AT THE HIGHER PLATFORMS AROUND
ISLE ROYALE. THE GALE WARNING THAT IS IN PLACE LOOKS TO BE IN DECENT
SHAPE...ALTHOUGH DID EXPAND IT SOUTHWEST TO LSZ162. A COLD FRONT
ASSOCIATED WITH THE LOW WILL SWEEP SOUTHEAST ACROSS LAKE SUPERIOR
ON FRIDAY...SHIFTING THE WINDS TO THE NORTHWEST AND BRINGING AN END
TO THE GALES. BEHIND THE FRONT...EXPECT WINDS TO 25-30KTS BEFORE
SHIFTING MORE NORTHERLY BEHIND A SECONDARY TROUGH ON MOVING ACROSS
LAKE SUPERIOR ON SATURDAY. WINDS WILL DIMINISH BEHIND THE SECONDARY
TROUGH AS A HIGH PRESSURE RIDGE SHIFTS SOUTH INTO THE AREA
SATURDAY NIGHT. ANOTHER CLIPPER SYSTEM WILL MOVE OUT OF CANADA AND
THROUGH THE UPPER MISSISSIPPI VALLEY ON SATURDAY NIGHT AND THEN
SLIDE THROUGH WISCONSIN SUNDAY MORNING. THIS WILL KEEP WINDS UP TO
20KTS OUT OF THE NORTH-NORTHEAST. ANOTHER RIDGE WILL BUILD IN
BEHIND THIS CLIPPER AND KEEP WINDS 15KTS OR BELOW SUNDAY NIGHT INTO
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 PM THIS EVENING TO 9 AM EST FRIDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
646 AM CST THU JAN 22 2015
.UPDATE...
ISSUED AT 646 AM CST THU JAN 22 2015
STRATUS HAS MOVED INTO THE SOUTHWESTERN CWA...THE HRRR HAS A
DECENT HANDLE ON IT AND TAKES THE CLOUDS NORTHEASTWARD ACROSS THE
SOUTHERN CWA THROUGH MUCH OF THE MORNING. ADJUSTED GRIDS TO
REFLECT. AT THIS POINT DO NOT THINK THEY WILL BE AROUND ENOUGH TO
AFFECT TEMPS BUT WILL KEEP AN EYE ON THEM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 345 AM CST THU JAN 22 2015
PRECIP CHANCES AND TYPE WILL AGAIN BE THE PRIMARY CONCERN FOR THE
SHORT TERM.
NORTHWESTERLY FLOW ALOFT WILL CONTINUE...WITH A SFC LOW
STRENGTHENING OVER SOUTHERN CANADA IN RESPONSE TO A SHORTWAVE
TROUGH MOVING THROUGH THAT AREA. THIS WILL INCREASE THE PRESSURE
GRADIENT OVER THE CWA...WITH SOUTHWESTERLY WINDS PICKING UP TO
JUST BELOW ADVISORY CRITERA. THE SOUTHWEST WINDS WILL ALSO BRING
A WARMER AIR MASS BACK INTO THE REGION. WE SHOULD AGAIN GET INTO
THE 20S AND 30S EVEN WITH A COOL START THIS MORNING AND INCREASING
CLOUDS.
TONIGHT...THERE WILL BE A FAIRLY SIGNIFICANT SHORTWAVE DIGGING
FROM MANITOBA INTO NORTHERN ND. THE MODELS ARE A LITTLE MORE
CONSISTENT TODAY ON PUTTING OUT SOME PRECIP TONIGHT AND INTO
TOMORROW MORNING AS THE SHORTWAVE MOVES THROUGH THE CWA. THE RAP IN
FACT HAS SOME PRECIP MOVING IN AS SOON AS LATE AFTERNOON. THINK
THIS IS A BIT OVERDONE GIVEN THE TIME IT TAKES TO SATURATE AND
WILL KEEP POPS OUT UNTIL AFTER 00Z FRIDAY. HAVE SOME 20-30 POPS
MOVING THROUGH TONIGHT BEFORE EXITING TOMORROW MORNING. WHILE THE
AMOUNTS WILL BE LIGHT...THERE WILL BE A VERY STRONG WARM LAYER
ALOFT MOVING IN WITH THE SOUTHWESTERLY WINDS. SFC TEMPS IN THE
EVENING MAY ACTUALLY STILL BE ABOVE FREEZING BUT AS THE BOUNDARY
LAYER COOLS OFF SOME FREEZING RAIN IS DEFINITELY POSSIBLE. TOO
MUCH UNCERTAINTY FOR ANY HEADLINES AT THIS POINT BUT WILL KEEP AN
EYE FOR SOME LIGHT ICE ACCUMULATIONS.
FRIDAY...THE UPPER SHORTWAVE WILL DIG DOWN INTO MN...ALLOWING THE
SFC TROUGH TO MOVE EAST AND WINDS ACROSS THE CWA SHIFT TO THE WEST
AND NORTHWEST ON THE BACKSIDE OF THE LOW. WITH THE WEST WINDS
THINK WE WILL SEE SOME REDUCTIONS IN CLOUDS...AND WITH 850MB TEMPS
STILL WELL ABOVE ZERO C...FRIDAY LOOKS TO BE VERY MILD WITH HIGHS
IN THE 30S AND SOME SPOTS NEAR THE 40 MARK.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU JAN 22 2015
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE MODELS ALL BRING A
FAIRLY SIGNIFICANT SHORTWAVE DOWN INTO THE REGION...BUT STRUGGLE
ON TIMING AND STRENGTH. WARM AIR ADVECTION WILL CONTINUE THROUGH
FRIDAY NIGHT AHEAD OF THE SYSTEM SO THERE WILL BE A CONTINUED
CHANCE FOR SOME MIXED PRECIP WHEN IT MOVES IN. THE ECMWF IS FASTER
THAN THE OTHER DETERMINISTIC MODELS...AND THE 00Z RUN HAS COME IN
FURTHER WEST WITH SIGNIFICANT PRECIP. THIS PUTS IT MORE SIMILAR TO
THE NAM WHICH IS FURTHEREAST WEST WITH DEFORMATION BAND PRECIP AND
IS THE STRONGEST WITH QPF. THE GFS ON THE OTHER HAND...HAS THE
MAIN PRECIP OVER THE FAR EASTERN COUNTIES. WITH HIGH UNCERTAINTY
WILL CONTINUE TO KEEP THE BLENDED SOLUTION...WHICH HAS THE HIGHEST
POPS FOR SATURDAY NIGHT. WITH FAIRLY WARM TEMPS CONTINUING INTO
SATURDAY THERE COULD BE SOME MIXED PRECIP...SO WENT WITH SOME
LIGHT ICING AND A FEW INCHES OF SNOW...MAINLY OVER THE
NORTHEASTERN COUNTIES.
SUNDAY THROUGH WEDNESDAY...LONG WAVE RIDGE ESSENTIALLY REMAINS OVER
WESTERN NORTH AMERICA...PERHAPS RETROGRADES A BIT TROUGH THE
PERIOD. LONG WAVE TROUGH REMAINS OVER EASTERN NORTH AMERICA.
PATTERN INTENSIFIES THROUGH DAY 5 THEN DE AMPLIFIES THEREAFTER.
PATTERN REMAINS THE SAME THROUGH THE PERIOD WITH PROGRESSIVE SHORT
WAVES MOVING THROUGH THE FLOW. SHORT WAVE RIDGE MOVES EAST OVER
THE NORTHERN PLAINS ON WED. THE ECMWF WAS FASTER THAN THE GFS
THROUGH THE PERIOD. GFS AND ECMWF HAVE TRENDED FASTER OVER THE
LAST COUPLE RUNS. WILL PREFER THE ECMWF.
HIGH TEMPS HAVE BEEN INCREASED A DEGREE OR SO FOR SUN AND INCREASED
TWO TO FOUR DEGREES FOR MON THROUGH WED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 646 AM CST THU JAN 22 2015
SOME MVFR/IFR STRATUS HAS MOVED INTO SOUTHEASTERN ND AND MAY
AFFECT THE KFAR FOR THE NEXT FEW HOURS...BUT OTHERWISE CONDITIONS
ARE VFR. THERE WILL BE INCREASING HIGH AND MID CLOUDS...BUT THE
MAIN CONCERN WILL BE WINDS. SOUTHWEST WINDS WILL CLIMB TO THE 15
TO 20 KT RANGE WITH GUSTS APPROACHING 30 KTS AT SOME SITES. WINDS
WILL DECREASE A BIT TONIGHT AND SHIFT TO THE WEST BUT WILL STILL
BE ABOVE 12 KTS. THE MODELS TRY AND BRING IN SOME STRATUS DURING
THE LATER PART OF THE PERIOD. FOR NOW JUST INCLUDED KBJI WITH MVFR
CONDITIONS AND KEEP EVERYWHERE ELSE VFR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...JR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
503 AM CST THU JAN 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST THU JAN 22 2015
TRANQUIL WEATHER DURING THE PERIOD WITH CLOUDS BEING THE MAIN
FORECAST PROBLEM AS HIGH PRESSURE TRIES TO BUILD IN FROM THE
DAKOTAS. GOES FOG IMAGERY SHOWING WIDESPREAD CLOUDS OVER IA/WI AND
ERN DAKOTAS/NEB. SOME CLEARING IS OUT THERE ACROSS WRN MN BUT
THIS HAS STRUGGLED TO MAKE MUCH PROGRESS OVER THE PAST HOURS.
DAKOTAS/NEBRASKA CLOUD IS NOW MOVING EAST AND RIGHT IN THE HEART
OF THE SURFACE HIGH PRESSURE RIDGE AXIS FROM KINL-KLBF.
LOW-LEVEL RIDGE AXIS WILL SHIFT THROUGH AND TO THE SOUTHEAST TODAY
RAPIDLY BACKING THE FLOW TO W/SW BY AFTERNOON...CONTINUING TO
BRING THE DAKOTAS CLOUD TOWARD THE AREA. SO...IT APPEARS SOME
BREAKS WILL WORK IN...BUT ALSO MORE CLOUD. 925MB FLOW FROM THE
W/SW INCREASING TO 40 KTS TONIGHT SHOULD KEEP THE CLOUDS MOVING
NORTHEAST AND PROVIDE AN INCREASING PROBABILITY OF CLEARING FROM
THE SW. SO...HAVE TRENDED SOME SLOW PARTIAL CLEARING FROM THE WEST
TODAY...AND SOUTHWEST OVERNIGHT /PER BROAD 22.03Z SREF AND MESO
MODEL CEILING FORECAST TRENDS/. TEMPERATURES WILL COOL THIS
EVENING IF CLEARING IS PRESENT BUT INCREASING WIND FLOW SHOULD
STOP THAT FALL AFTER MIDNIGHT. OVERALL HAVE INCREASED TEMPERATURES
A FEW DEGREES THROUGH SATURDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 353 AM CST THU JAN 22 2015
GOES WATER VAPOR IMAGERY SHOWING ENERGY CRASHING ONTO CENTRAL BRITISH
COLUMBIA COAST AT 06Z WITH A MODERATE POTENTIAL VORTICITY ANOMALY
AND WEAK-MODERATE 500-300 MB QG CONVERGENCE FORCING FOR LIFT. THE
22.00Z DETERMINISTIC MODELS IN GOOD AGREEMENT ON THE FORCING
STRENGTH AND TRACK OF THESE DYNAMICS. THE MAIN LIFT FOR THIS
SHORTWAVE TROUGH TRAVELS NORTH OF LAKE SUPERIOR WITH SOME WEAK
FORCING TRAILING SOUTHWEST IN THE TROUGH...AFFECTING MAINLY
NORTHERN WISCONSIN. THE LIFT ARRIVES FRIDAY AFTERNOON AND WARM
ADVECTION IN THE LOW LEVELS BRINGS A WARM LAYER ABOVE 0C /1-2C/ IN
FROM THE WEST. SATURATION APPEARS TO BE TOP-DOWN WITH THIS LIFT
AND LOW-LEVEL CLOUD SHOULD BE NORTH OF THE AREA...THUS DRIZZLE OR
FREEZING DRIZZLE HAVE BEEN REMOVED FROM THE FORECAST. THE WARM
LAYER OF 1-2C WILL QUICKLY /1-2 HOURS/ DIABATICALLY COOL...SO SOME
SLEET IS POSSIBLE AT FIRST SHOULD PRECIPITATION REACH THE SURFACE...THEN
RAIN/SNOW DEPENDING ON LOW-LEVEL TEMPERATURES. SHOULD BE A LOW/NO QPF
EVENT AND HAVE MINIMAL/NO IMPACT. HIGHEST PRECIPITATION CHANCES
/40 PERCENT/ ARE FOUND ACROSS NORTH CENTRAL WI FRIDAY
AFTERNOON...DECREASING SOUTHWESTWARD TO ONLY 20 PERCENT OVER SERN
MN WHERE LOW-LEVELS APPEAR VERY DRY PER 22.00Z GFS/NAM SOUNDINGS.
GFS SEEMS A BIT TOO SATURATED GIVEN THE LIFT/FORCING MAGNITUDE
AND PREFER HOW THE NAM IS HANDLING THE CLOUD PHYSICS OF THIS
EVENT /DRIER LOW-LEVELS AND MORE SUB-CLOUD SUBLIMATION FURTHER
SOUTHWEST/.
IT STILL APPEARS SATURDAY NIGHT AND SUNDAY /MORNING/ WILL HAVE A
MODERATE CHANCE OF ACCUMULATING SNOW IN THE REGION. THIS
SHORTWAVE TROUGH ENERGY WAS LOCATED NEAR 170W/30N IN THE BASE OF
THE ENERGETIC AND DEEP PACIFIC LONGWAVE TROUGH. THE DETERMINISTIC
MODELS AND LATEST SREF RUNS ARE ALL PAINTING THE SAME PICTURE...A
MODERATELY FORCED SYSTEM AND SURFACE CYCLONE MOVING THROUGH DURING
THIS PERIOD WITH ACCUMULATING SNOW IN THE 1-3 INCH RANGE.
HOWEVER...THE ENVELOPE FOR THIS SNOW AXIS AND LOW TRACK EXTEND
FROM THE MI U.P. /CANADIAN GLOBAL/ TO I-35 IN MINNESOTA
/ECMWF...NAM/. SO...WITH THE SHORTWAVE TROUGH OVER THE MIDDLE
OCEAN AND IT BEING 3 DAYS PRIOR TO ARRIVAL...WILL STEP SLOWLY INTO
THIS ONE. HAVE INCREASED PRECIPITATION CHANCES INTO THE 55 PERCENT
RANGE ACROSS NORTHCENTRAL WI...LOWER ELSEWHERE...AND FORECAST A
BROAD AREA OF 1-2 INCHES SATURDAY NIGHT. NOT CONFIDENT ENOUGH TO
DETAIL TIMING ON THIS FORECAST YET. FORCING AND LIFT CONSENSUS IN
THE MODELS IS PRETTY IMPRESSIVE AND FRONTOGENESIS/INSTABILITY IS
AS WELL...SO IF THESE PLAYERS COME TOGETHER...IT COULD BE HIGHER
SNOW AMOUNTS TOWARD AN ADVISORY LEVEL.
MONDAY-WEDNESDAY...RIGHT NOW IT APPEARS TO BE A BENIGN WEATHER
PATTERN WITH SOME SMALL SNOW CHANCES...AND TEMPERATURES REMAINING
ABOVE NORMAL. USED THE BLEND OF DETERMINISTIC MODELS FOR THIS
PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 503 AM CST THU JAN 22 2015
CLOUD TRENDS THROUGH TODAY ARE THE MAIN CONCERN WITH SOME
UNCERTAINTY ON HOW THINGS WILL DEVELOP. CEILINGS FOR THE MOST PART
THIS MORNING ARE MVFR...ALTHOUGH THERE IS AN AREA OF LOWER CLOUDS
THAT FLOATED THROUGH KRST AND BROUGHT THE CEILING DOWN TO IFR.
THIS APPEARS TO BE TIED TO A BIT A WIND SHIFT FROM NORTHWEST TO
WEST. IF THESE HOLD TOGETHER...SHOULD SEE A LOWERING OF THE
CEILING THIS MORNING AT KLSE...BUT STILL EXPECTING THEM TO REMAIN
MVFR. THE CLEARING IS WORKING WEST ACROSS SOUTH DAKOTA AND THIS
SHOULD MAKE ITS WAY ACROSS BOTH TAF SITES THIS AFTERNOON.
HOWEVER...BOTH THE 22.09Z RAP AND 22.06Z NAM SUGGEST THE MOISTURE
WILL REMAINED TRAPPED UNDERNEATH THE INVERSION WITH LITTLE CHANCE
FOR CLEARING UNTIL LATE TONIGHT. FOR NOW...WILL GO WITH THE TRENDS
SEEN ON THE SATELLITE AND THE PREVIOUS FORECAST...BUT DELAY THE
TIMING OF THE CLEARING SOME FROM THE PREVIOUS FORECAST. THE WINDS
WILL INCREASE TO OVER 10 KNOTS THIS EVENING AHEAD OF AN
APPROACHING STORM SYSTEM FROM CANADA. THE NAM INDICATES GOOD LOW
LEVEL LAPSE RATES WILL DEVELOP TO ALLOW SOME GUSTS TO
OCCUR...ESPECIALLY AT KRST. IF THE SURFACE WINDS DO NOT
INCREASE...WIND SHEAR WILL BE A POSSIBILITY AT BOTH TAF SITES
WITH SPEEDS OF 35 TO 40 KNOTS AROUND 2000 FEET AFTER 23.06Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS TUCSON AZ
254 PM MST THU JAN 22 2015
.SYNOPSIS...AN UPPER LOW WILL DROP SOUTH ALONG THE NEW MEXICO BORDER
THROUGH THIS EVENING GENERATING A FEW SHOWERS ALONG THE BORDER AND
FORCING COLDER ACROSS THE STATE ON NORTHERLY BREEZES. DRY AND
MILDER WEATHER WILL RETURN THIS WEEKEND BEFORE A LOW WEST OF BAJA
DIRECTS MOISTURE NORTH AND BRINGS A THREAT OF SHOWERS TO SOUTHERN
ARIZONA SUNDAY NIGHT INTO TUESDAY.
&&
.DISCUSSION...PRIMARY CONCERN FOR THE NEXT WEEK IS THE POTENTIAL FOR
SHOWERS...AND POSSIBLY A FEW THUNDERSTORMS...MONDAY AND TUESDAY.
MORE ON THAT IN A MOMENT.
CURRENTLY...VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS SHOW
THE LOW CLOUDS AND LIGHT PRECIP ONGOING JUST ALONG THE AZ AND NEW
MEXICO BORDER. IN ADDITION...THE TIGHT PRESSURE GRADIENT IN PLACE
ACROSS SOUTHEAST AZ IS RESULTING IN GUSTY SURFACE WINDS. FOR
TONIGHT...WRF AND HRRR OUTPUT SUGGESTS EASTERLY LOW LEVEL FLOW WILL
CONTINUE THROUGH THE MORNING HOURS. THE RESULTING DOWNSLOPE WINDS
SHOULD KEEP LOW TEMPERATURES A FEW DEGREES HIGHER THAN MOS GUIDANCE
SUGGESTS IN VALLEY LOCATIONS TO THE WEST OF MOUNTAIN RANGES...THIS
INCLUDES LOCATIONS SUCH AS TUCSON AND SAFFORD.
THE UPPER LEVEL PATTERN MOVES INTO A TRANSITIONAL PHASE STARTING
TOMORROW AS THE UPPER LEVEL LOW PRESSURE SYSTEM IN NEW MEXICO SWEEPS
TO THE EAST...AND HIGH PRESSURE BUILDS OVER THE WESTERN U.S.. A
PRONOUNCED SHORT WAVE TROUGH EMBEDDED IN THE UPPER RIDGE DIVES SOUTH
TOWARD ARIZONA TOMORROW MORNING. THIS SHORT WAVE EVENTUALLY DIGS
SOUTHWEST...INTENSIFIES...AND BECOMES CUT OFF FROM THE MAIN PATTERN
JUST OFF THE COAST OF BAJA CALIFORNIA. THIS RESULTS IN AN UPPER
LEVEL REX BLOCK PATTERN WHERE WITH THE INTENSE HIGH PRESSURE RIDGE
EXTENDING OVER THE PACIFIC NORTHWEST AND THE CUT OFF LOW OFF THE
BAJA PENINSULA. THIS PATTERN SHOULD STICK AROUND FOR A FEW DAYS AND
WHILE THE PACIFIC NORTHWEST HEATS UP TO NEAR RECORD LEVELS...THOSE
OF US IN THE SOUTHWEST WILL SEE TEMPERATURES WARM UP A FEW DEGREES
ABOVE AVERAGE. IN ADDITION...MOIST AIR FROM THE PACIFIC WILL BE
TRANSPORTED BY THE LOW PRESSURE SYSTEM INTO SOUTHERN ARIZONA. BY
TUESDAY MORNING...PRECIPITABLE WATER VALUES WILL SKYROCKET TO AROUND
1 INCH...WHICH DOES NOT SEEM HIGH...BUT IS ACTUALLY NEAR THE 99TH
PERCENTILE FOR MID JANUARY.
ONCE THE CUT OFF LOW DISLODGES FROM THE BLOCKING PATTERN ON
MONDAY...IT WILL PUSH NORTH AND BING THE MOISTURE...ALONG WITH
PLENTY OF LIFT...TO SUPPORT PRECIPITATION ACROSS SOUTHEAST ARIZONA.
RIGHT NOW...IT APPEARS THE BEST SHOT FOR PRECIPITATION WILL TAKE
PLACE TUESDAY MORNING THROUGH THE AFTERNOON HOURS. SNOW LEVELS
SHOULD REMAIN FAIRLY HIGH AS THIS SYSTEM WILL BE RELATIVELY WARM FOR
MID JANUARY GIVEN ITS TIME SPENT OFF THE BAJA PENINSULA. RIGHT
NOW...WE ARE THINKING SNOW LEVELS MAY FALL TO AROUND 8000 FEET OR
SO. THEIR SHOULD BE SUFFICIENT COLD AIR ALOFT...AND WARM LOW LEVEL
AIR...TO SUPPORT A LIGHTNING STRIKE OR TWO. THE CURRENT FORECAST
DOES NOT MENTION THUNDERSTORMS AS I AM NOT CONFIDENT ON EXACTLY
WHERE THUNDER IS MOST LIKELY...BUT THE FAVORED AREA IS PIMA COUNTY
TO THE WEST. RAINFALL AMOUNTS ARE STILL UP IN THE AIR...BUT WE COULD
SEE A FEW TENTHS WITH A ISOLATED AMOUNTS NEAR ONE HALF INCH.
FOLLOWING THE EARLY WEEK SYSTEM...THE UPPER PATTERN BECOMES MORE
PROGRESSIVE AND GIVES WAY TO SHORT TERM RIDGING THROUGH MID
WEEK...FOLLOWED BY ANOTHER LOW PRESSURE SYSTEM BY NEXT WEEKEND. THE
ECMWF EVEN SUGGESTS ANOTHER REX BLOCK PATTERN STARTING NEXT
FRIDAY...WHILE THE GFS IS MORE PROGRESSIVE AND BRINGS A TROUGH
THROUGH BY SATURDAY. EITHER WAY...THE LONG TERM FORECAST IS FAIRLY
UNSETTLED AT THIS POINT.
JJB
&&
.AVIATION...VALID THRU 24/00Z.
VFR CONDITIONS WILL PREVAIL IN AND AROUND THE TERMINALS OVER THE
NEXT 24 HOURS. LOWER CEILINGS ARE POSSIBLE EAST OF KDUG AS AN AREA
OF LOW PRESSURE MOVES EAST OF THE AREA. LOW CLOUDS MAY OBSCURE
TERRAIN AT TIMES IN AND AROUND THE CHIRICAHUA MOUNTAINS. EAST WINDS
WILL IMPACT MOST AREAS THIS AFTERNOON AND OVERNIGHT WITH GUSTS AS
HIGH AS 25 MPH. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...LINGERING CLOUDS AND POSSIBLE SHOWERS WILL IMPACT
AREAS ALONG THE NEW MEXICO BORDER. THE MAJORITY OF PRECIPITATION
WILL REMAIN ON THE NEW MEXICO SIDE...WITH AREAS ALONG THE
CHIRICAHUA MOUNTAINS SEEING THE BEST CHANCE ON THE ARIZONA SIDE.
BRISK EAST WINDS WILL IMPACT MOST AREAS THIS AFTERNOON AND
OVERNIGHT. WIND GUSTS AS HIGH AS 25 MPH WILL BE POSSIBLE. DRY AND
STABLE WEATHER WILL BUILD BACK IN WITH WARMING TEMPERATURES THROUGH
THE WEEKEND.
MOISTURE WILL BE ON THE INCREASE EARLY NEXT WEEK AS LOW PRESSURE OFF
BAJA COAST LIFTS NORTH. SHOWER POTENTIAL WILL BE ON THE
INCREASE...WITH THE BEST CHANCE OVER WESTERN PORTIONS OF PIMA
COUNTY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
925 AM PST Thu Jan 22 2015
.Synopsis...
Dry weather with areas of late night/morning valley fog expected
this week. Temperatures expected to remain above to well above
normal through the extended period, peaking over the weekend.
Potential wet weather Tuesday and Wednesday of next week.
&&
.Discussion...
Weak upper trough moving through large scale upper ridging along the
west coast is bringing some higher level cloudiness to Interior
NorCal while any associated precip is remaining north of California.
Meanwhile extensive stratus deck developed in the Central Valley
overnight which has limited fog development, except along the
northeast foothills and Motherlode where the deck banks up along the
ground. HRRR showing deck will erode from north to south late
morning into the afternoon as weak synoptic UVM with upper trough
comes into play. High temperatures today expected in the 50s to mid
60s.
Models similar in pumping up upper level ridging over NorCal into
the weekend with 5H heights in the mid 580s DM by Saturday. This
will result in unseasonably warm temperatures, especially in the
Northern Sacramento Valley where guidance is pushing max temps into
the mid 70s for Saturday and Sunday. Forecast highs and record max
temps for Redding and Red Bluff for this weekend are below:
Date Location Forecast Record
1/24 Redding 75 77
1/24 Red Bluff 73 78
1/25 Redding 76 78
1/25 Red Bluff 72 78
Along with well above normal temperatures this weekend, models are
showing some locally breezy north to easterly winds possible, mainly
over the eastern foothills/mountains. This increased low level flow
may help to hinder valley fog development under increased
subsidence.
PCH
&&
.Extended Discussion (Monday through Thursday)
The upper level ridge will shift east into the Great Basin on
Monday, though subsidence will continue to bring dry weather that
day. With southerly flow behind the upper level ridge, medium-
range models continue to suggest that subtropical moisture from
west of Mexico will be drawn northward toward the Western US. The
GFS brings this moisture along the Great Basin and the Desert
Southwest, with the best chance of NorCal precipitation confined
to the mountains. The ECMWF and GEM are both a bit farther
westward with the moisture, and would bring a better chance of
precipitation across NorCal. With this being a somewhat unusual
setup for the wintertime, we blended the solutions together to
give a roughly 25-40% chance of rain across the area. Expect the
models to continue to change in timing and strength of this system
over the next several runs.
Model continuity worsens even further beyond Tue-Wed of next week,
and there is little confidence in any particular solution beyond
that point.
Dang
&&
.Aviation...
Areas MVFR/IFR with isold LIFR in ST in Cntrl Vly into this aftn and
agn poss tngt into Fri mrng, otrw mnly VFR for Intr NorCal nxt 24
hrs.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1133 AM CST THU JAN 22 2015
.SYNOPSIS...
ISSUED AT 318 AM CST THU JAN 22 2015
HIGH PRESSURE RIDGE WILL MOVE THROUGH THE AREA TODAY WITH THE
NEXT IN THE SERIES OF FAST MOVING LOW PRESSURE SYSTEMS DROPS
SOUTHEAST THROUGH ONTARIO ON FRIDAY. ANOTHER SYSTEM WILL MOVE OUT
OF NRN ALBERTA AND BRUSH NERN IA SATURDAY NIGHT...AND MOVE INTO
THE MID ATLANTIC SEABOARD BY SUNDAY EVENING. JET STREAM WILL
REMAIN NORTH OF THE AREA THROUGH THE FORECAST PERIOD AS WILL THE
STORM TRACK.
&&
.SHORT TERM /TODAY/...
ISSUED AT 318 AM CST THU JAN 22 2015
MAIN FORECAST CONCERN TODAY DEALT WITH CLOUD COVER AND
TEMPERATURES. THE STRATUS DECK LOOKS TO GRADUALLY THIN OUT AND
DISSIPATE THROUGHOUT THE DAY AND SHOULD SEE MORE SUNSHINE THAN
CLOUD COVER BY AROUND 19Z-20Z. BOTH THE HRRR AND HOPWRF HAVE
CLOUD COVER DISSIPATING B/T 18-21Z THIS AFTERNOON FROM SOUTHWEST
IOWA TO THE NORTHEAST. THIS COINCIDES WITH THE SURFACE HIGH
SHIFTING OVER MUCH OF THE STATE BY MIDDAY AND ADVECTS IN SOME
DRIER AIR AND ALLOWS THE INVERSION TO WEAKEN. THUS...WENT SLIGHTLY
ABOVE PREVIOUS FORECAST OVER THE CENTRAL TO SOUTHWEST WHERE THE
CLOUD COVER SHOULD CLEAR OUT A LITTLE SOONER. WENT CLOSER THE
MAVMOS/SREF FOR MAX TEMPS TODAY.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 318 AM CST THU JAN 22 2015
NOT A LOT OF CHANGE WITH THE IDEAS OF THE MODELS FROM THE PAST FEW
DAYS INTO TODAY. WEATHER SYSTEM OUT OF ALBERTA WILL BRING A CHANCE
FOR MIXED PRECIPITATION OVER THE NORTHEAST...WITH MOSTLY RAIN
OVER THE SOUTHWEST SATURDAY NIGHT INTO SUNDAY. NO REAL COLD AIR
FOLLOWING THE SYSTEM AND WILL SEE MILD LATE JANUARY WEATHER
CONTINUE.
A THIRD IN THE SERIES OF LOW PRESSURE SYSTEMS WILL PASS WELL TO
THE NORTH OF THE AREA FOR MID WEEK...BRINGING IN VERY MILD AIR.
TUE WILL BE QUITE WARM...MAINLY SOUTHWEST...WITH MORE WIDESPREAD
WARMING ON WED. THE ECMWF IS SHOWING THE +16 AT H8 MAKING IT INTO
THE STATE. WENT WARMER THAN MOS AND MORE IN LINE WITH THE ECMWF
OMS FORECASTS FOR WED. ALL SIGNS LOOK GOOD FOR GOOD WARMING OVER
NON-SNOW COVERED AREAS.
THE END OF THE WEEK WILL FEATURE A CHANGE IN THE PATTERN.
INDICATIONS POINT TO A STRONG PUSH OF COLD AIR BY THE
WEEKEND...LIKELY RIVALING THE COLD OUTBREAK WE SAW THE WEEK OF
THE 5TH.
&&
.AVIATION...22/18Z
ISSUED AT 1133 AM CST THU JAN 22 2015
LOW STRATUS SHIELD CONTINUES TO BLANKET THE REGION AND IS
STUBBORNLY REFUSING TO MOVE OUT. THE BACK EDGE TO OUR WEST IS
MAKING SLOW PROGRESS...AND BELIEVE THAT ONCE UPPER LEVEL RIDGING
MOVES OVERHEAD AND SURFACE FLOW INCREASES LATE TODAY/EARLY TONIGHT
AND CLOUDS WILL FINALLY CLEAR OUT. THERE IS SOME UNCERTAINTY AS TO
WHETHER THEY MAY STALL AFTER SUNSET AND LINGER IN OUR
EAST/SOUTHEAST OVERNIGHT...BUT FOR NOW HAVE CLEARED THEM OUT AFTER
SUNSET. IN ANY CASE THEY WILL AFFECT THE TERMINALS FOR THE FIRST
SIX HOURS OF THE TAFS WITH SLOWLY RISING MVFR CIGS...AND POSSIBLY
IFR AT MCW EARLY THIS AFTERNOON.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MS JAN 15
SHORT TERM...PODRAZIK
LONG TERM...MS JAN 15
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
317 PM CST THU JAN 22 2015
.DISCUSSION...
BROAD AREA OF RAIN COVERING OUR ENTIRE COUNTY WARNING AREA THIS
AFTERNOON. TEMPERATURES NOW HOVERING IN THE MID 40S TO LOWER 50S.
OUR 100 PERCENT POP FORECAST LOOKING RIGHT ON THE MONEY...SO A JOB
WELL DONE TO OUR STAFF.
ON THE LARGER CANVAS...IN THE UPPER LEVELS...A TROUGH OF LOW
PRESSURE IS CURRENTLY WORKING ACROSS WEST TEXAS WITH AN ABUNDANCE OF
ENERGY RIDING THROUGH OUR AREA AT THE MOMENT. THIS HAS SPAWNED AN
ELONGATED AREA OF SURFACE LOW PRESSURE OFF THE TEXAS OFFSHORE COASTAL
WATERS FROM BAFFIN BAY TO GALVESTON. MASSIVE AMOUNTS OF GULF
MOISTURE TRAPPED ALONG THE SOUTHEAST TEXAS & LOUISIANA COASTAL
WATERS IN A VERY RICH CONVERGENCE ZONE WHERE LARGE SWATHS OF RAIN
ARE BEING CREATED AND THEN MOVED INLAND.
OBVIOUSLY...THIS IS GOING TO CREATE A VERY GENEROUS AMOUNT OF 1 1/2
TO 2 INCH RAIN AMOUNTS WITH ISOLATED AMOUNTS UP TO THREE INCHES. THE RAIN
WILL BE HERE TO STAY THROUGH THE NIGHT AS OUR HRRR & GFS MODELS
SHOWING OUR NEWLY BORN SURFACE LOW MOVING WEST TO EAST ACROSS OUR
NORTHWEST GULF OF MEXICO THROUGH EARLY MORNING FRIDAY. I RAISED THE
WIND ADVISORY TODAY THROUGH MIDNIGHT FOR I-10 CORRIDOR SOUTH
BECAUSE THIS SURFACE LOW WILL TIGHTEN UP THE WIND FIELD ACROSS OUR
COASTAL AREAS WITH SOME GUSTS AT TIMES FURTHER NORTH AT LEAST
UNTIL MIDNIGHT.
SO...ELEVATED WINDS ARE GOING TO BE A PROBLEM UNTIL MIDNIGHT ALONG
THE COASTAL AREAS AND THE RAINS ARE GOING TO BE THE BIGGEST
PROBLEMS FOR THE ENTIRE AREA OVER THE NEXT 24 HOURS. THE SURFACE
LOW WILL MOVE EAST OF OUR AREA BY NOON FRIDAY...HOWEVER WE WILL
CONTINUE TO EXPECT LIGHT RAIN OR SHOWERS THROUGH THE AFTERNOON
FRIDAY AS THE UPPER LEVEL SYSTEM TRACKS EVEN CLOSER TO US.
RAIN SHOULD EXIT THE ENTIRE AREA BY FRIDAY NIGHT WITH HIGH
PRESSURE BUILDING BACK INTO THE AREA. THE REST OF THE FORECAST
THROUGH DAY SEVEN LOOKS DRY WITH COOL TEMPERATURES THROUGH SUNDAY
MORNING WITH A SLOW WARM-UP FOR THE REST OF NEXT WEEK.
&&
.MARINE...
SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT UNTIL 6 PM FRIDAY AS SOUTHEAST
FLOW THIS AFTERNOON TRANSITIONS TO A NORTHERLY FLOW LATER TONIGHT
WITH THE PASSAGE OF A NORTHWEST GULF SURFACE LOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 44 48 37 57 / 100 30 20 10
KBPT 44 49 37 58 / 100 30 10 0
KAEX 41 45 34 56 / 100 40 20 0
KLFT 46 48 38 56 / 100 30 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR ACADIA-CALCASIEU-
EAST CAMERON-IBERIA-JEFFERSON DAVIS-LAFAYETTE-LOWER ST.
MARTIN-ST. MARY-UPPER ST. MARTIN-VERMILION-WEST CAMERON.
TX...WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR JEFFERSON-ORANGE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST FRIDAY FOR COASTAL WATERS
FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM-COASTAL WATERS
FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM-COASTAL
WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA
OUT 20 NM-WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM
20 TO 60 NM-WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM
20 TO 60 NM-WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA FROM 20 TO 60 NM.
SMALL CRAFT EXERCISE CAUTION UNTIL MIDNIGHT CST TONIGHT FOR
CALCASIEU LAKE-SABINE LAKE-VERMILION BAY.
&&
$$
PUBLIC/MARINE...06
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
347 PM EST THU JAN 22 2015
.SHORT TERM... THROUGH TONIGHT
MAIN FORECAST CHALLENGE IS WITH CLOUD COVER OVERNIGHT. SPLIT FLOW
PATTERN IN PLACE OVER NORTH AMERICA WITH SOUTHEAST MICHIGAN
POSITIONED IN THE POLEWARD ENTRANCE REGION OF A STRONG JET AXIS OVER
THE OHIO VALLEY. THIS WILL PROMOTE ACTIVE SUBSIDENCE THROUGH THE
PERIOD...AS EVIDENCED BY SPRAWLING SURFACE HIGH OVER THE WESTERN
GREAT LAKES. EXTENSIVE STRATUS DECK OVER THE UPPER MIDWEST HAS SHOWN
GOOD SIGNS OF CLEARING OVER WISCONSIN/UPPER MICHIGAN WITH BACK EDGE
OF THE STRATUS WORKING INTO NORTHERN MICHIGAN AND ACROSS LAKE
MICHIGAN. LINEAR EXTRAPOLATION OF THIS CLEARING WOULD WORK IT INTO
SOUTHEAST MICHIGAN AFTER 00Z. HOWEVER...CLIMATOLOGY IS A FACTOR
WORKING AGAINST CLEARING. NAM AND RAP RH PROGS ARE NOT MUCH HELP
HERE AS THEY DID NOT SHOW THE AREA OF CLEARING TO OUR WEST...HOWEVER
THEY DO SHOW POCKETS OF CLEARING OVER THE UPPER MIDWEST OVERNIGHT.
THE UPSHOT IS...TRENDED A BIT MORE OPTIMISTIC WITH CLOUD COVER THAN
PREVIOUS FORECAST...BUT KEPT PARTLY TO MOSTLY CLOUDY SKIES IN ORDER
THAT THE FORECAST NOT BOUNCE AROUND TOO MUCH AS CONFIDENCE IN
CLEARING SKIES IS STILL NOT HIGH.
CLOUD COVER WILL IMPACT LOW TEMPS AS WELL. SIDED WITH THE WARMER MET
MOS. SOME ROOM FOR TEMPS TO DROP BELOW FORECAST LOWS IF CLEARING IS
REALIZED...HOWEVER STILL THINK MAV MOS IS A BIT TOO LOW AS IT IS
UNDERDOING SURFACE DEWPOINTS. ALSO...INCREASING SW GRADIENT FLOW
TOWARD THE END OF THE FORECAST PERIOD SHOULD LIMIT POTENTIAL TEMP
DROP OVER NORTHERN PARTS OF THE FORECAST AREA. THE INCREASED
PRESSURE GRADIENT WILL OCCUR AS AN EXPANSIVE CYCLONE DEEPENS OVER
NORTHERN ONTARIO.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
UPPER LEVEL PATTERN BECOMES QUITE COMPLEX TO END THE WEEK. AMPLIFIED
RIDGING OVER THE WESTERN CONUS GET FOLDED OVER IN THE GREAT LAKES
FRIDAY WHICH TRIES TO PINCH OFF THE BASE OF THE TROUGH OVER THE FOUR
CORNERS. ENERGETIC SOUTHERN STREAM KEEPS IT FAIRLY PROGRESSIVE
PREVENTING A TRUE CUTOFF LOW FROM FORMING AS IT TRACKS ACROSS THE
SOUTHERN STATES. INCOMING NORTHERN STREAM ENERGY EVENTUALLY CARVES
OUT ANOTHER DOMINATE TROUGH BY THE END OF THE WEEKEND. AT THE
SFC...HIGH PRESSURE STRUNG OUT FROM THE CENTRAL PLAINS THROUGH THE
OHIO VALLEY AND TO THE EAST COAST ON FRIDAY WILL GET COMPRESSED
BETWEEN NORTHERN STREAM LOW TRACKING THROUGH NORTHERN ONTARIO AND
DEVELOPING SOUTHERN STREAM LOW UNDER THE AFOREMENTIONED PINCHED OFF
TROUGH. THE HIGH WILL MOVE OFF TO THE EAST BY SATURDAY AS THE
SYSTEMS DRAW NEARER EACH OTHER WITH THE ATTEMPTED PHASING OF THE
JETS. OVERALL THIS YIELDS A SOMEWHAT LOWER CONFIDENCE FORECAST AS
SLIGHT DIFFERENCES IN TIMING OF PHASING JETS OR LOCATION OF THE SFC
FEATURES USUALLY LEADS TO JUMPS IN THE FORECAST. LUCKILY IN THIS
CASE...THE PHASING IS ADVERTISED FAR ENOUGH DOWN STREAM TO NEGATE SOME
OF THE TYPICAL CONCERNS.
FOR FRIDAY...WITH HIGH PRESSURE LOCKED AT THE SFC...THE LOW PASSING
THROUGH ONTARIO WILL DROP A COLD FRONT/TROUGH THROUGH LOWER MI IN
THE AFTERNOON. WITH THE HIGH SLIDING TO OUR EAST...WINDS WILL BECOME
SOUTHWESTERLY IN THE MORNING AHEAD OF THE TROUGH AS THE RIDGE AND
TROUGH TIGHTEN THE PRESSURE GRADIENT OVER THE STATE. THESE SW WINDS
WILL BRING THE NOSE OF A THERMAL RIDGE INTO THE AREA THROUGH THE
AFTERNOON. THE WARM AIR WILL STEEPEN THE INVERSION BETWEEN 950-900MB
AS IT WARMS THE LAYER BETWEEN 700 AND 900MB. SO LOOK FOR ELEVATED
WINDS AROUND 15-20MPH WITH GUSTS TO AROUND 25MPH PEAKING IN THE
AFTERNOON. THE STOUT INVERSION WILL PREVENT BETTER MIXING FROM
BRINGING SOME OF THE HIGHER WINDS RIGHT ABOVE THE INVERSION DOWN TO
THE SFC.
THE WEAKENING COLD FRONT WILL ENTER CENTRAL MI AROUND MIDNIGHT WHICH
WILL BRING A CHANCE OF SNOW SHOWERS TO THE SAGINAW VALLEY AND
NORTHERN THUMB. MOISTURE POOLING AHEAD OF THE TROUGH IS DECENT WITH
PWATS INCREASING FROM UNDER 0.2 TO AROUND 0.5 INCHES. THE RIBBON OF
THETA E ALONG THE FRONT IS VERY NARROW WITH A GOOD GRADIENT ON THE
LEAD EDGE INITIALLY...BUT WEAKENING AS IT TRACKS THROUGH SOUTHERN
MI. SEE NO REASON TO DEVIATE FROM THE CHANCE/SLIGHT CHANCE POPS
RIGHT NOW FOR FRIDAY NIGHT. SEVERAL OTHER SMALL WAVES ARE ADVERTISED
TO SHOOT THROUGH THE DEVELOPING NW FLOW KEEPING LOW CHANCE POPS
THROUGH THE DAY SATURDAY. A SECOND...STRONGER COLD FRONT WILL DROP
INTO LOWER MI SATURDAY NIGHT STALLING ACROSS THE AREA AS THE
TRANSITION TO NW FLOW CONTINUES. WITH BL MOISTURE STILL PREVALENT
AND THE FRONT DRAPED ACROSS THE REGION WITH DECENT LAPSE RATES
THROUGH 800MB...WILL HOLD ONTO SOME LOW POP SNOW SHOWER MENTION
THROUGH SAT NIGHT.
CLIPPER DROPS OUT OF MANITOBA AND BEGINS INFLUENCING CONDITIONS
LATE SATURDAY NIGHT THROUGH SUNDAY. THIS SYSTEM COULD BRING IN
ANOTHER SHOT AT ACCUMULATING SNOW SUNDAY INTO EARLY MONDAY MORNING.
COLD AIR ADVECTION BEHIND THE FRONT ON MONDAY IS EXPECTED TO DROP
DAYTIME HIGH`S INTO THE TEENS AND LOW 20`S WITH SINGLE DIGIT
OVERNIGHT LOWS RETURNING FOR BOTH TUESDAY AND WEDNESDAY MORNING.
SCATTERED LIGHT SNOW SHOWERS WILL BE POSSIBLE ON THURSDAY AS ANOTHER
CLIPPER SWINGS THROUGH. TEMPS WARMING INTO THE LOW 30`S DURING THE
DAYLIGHT HOURS FOR THURSDAY AND FRIDAY.
&&
.MARINE...
A LOW PRESSURE SYSTEM TRACKING THROUGH CENTRAL CANADA WILL REACH
NORTHERN QUEBEC FRIDAY AFTERNOON. THIS SYSTEM WILL DROP A WEAKENING
COLD FRONT INTO THE REGION FRIDAY. THIS WILL TIGHTEN THE PRESSURE
GRADIENT BETWEEN IT AND THE EXITING SURFACE HIGH ALLOWING WINDS TO
AMPLIFY SOMEWHAT OVER CENTRAL AND NORTHERN LAKE HURON. THOUGH
SUSTAINED WINDS APPEAR TO REACH INTO THE MID 20 KNOT RANGE...WARM
AIR ALOFT AND A STEEP LOW LEVEL INVERSION APPEAR PREVENT STRONGER
GUSTS FROM REACHING THE SURFACE. FEEL FAIRLY CONFIDENT THAT WINDS
WILL GUST AT OR JUST ABOVE 30 KNOTS ACROSS NORTHERN AND CENTRAL LAKE
HURON. THOUGH GALE FORCE GUSTS CANNOT BE RULES OUT
ENTIRELY...CURRENT MODELS AND ANALYSIS SUGGEST WINDS TO THIS
STRENGTH WOULD BE QUITE SPORADIC...AND NOT WIDE SPREAD ENOUGH TO
WARRANT A GALE WARNING OR CONTINUING THE WATCH AT THIS TIME SO THE
WATCH HAS BEEN CANCELLED. EXTENSIVE ICE COVER IN THE LAKE HURON
NEARSHORE ZONES WILL PREVENT ANY WAVES DEVELOPING WITH THE OFFSHORE
FLOW TO AROUND 25 KNOTS...SO SMALL CRAFT ADVISORIES WILL NOT BE
NEEDED AT THIS TIME. COLD NORTHWEST FLOW THIS WEEKEND WILL KEEP
WINDS ELEVATED THROUGH THAT PERIOD...BUT WILL REMAIN BELOW GALE
FORCE.
&&
.AVIATION...ISSUED 1240 PM EST THU JAN 22 2015
MORNING FLURRIES HAVE ENDED AS DEEPER MOISTURE HAS EXITED THE
AREA. NOT EXPECTING VISIBILITY RESTRICTIONS FOR THE TAF PERIOD.
CIGS ARE SETTLING INTO THE MVFR RANGE...THOUGH THERE ARE
WEAKNESSES IN THE CLOUD DECK WITH CLEAR SKIES BETWEEN MBS AND FNT
AND OVER NORTHERN WISCONSIN. SOME UNCERTAINTY WITH EXTENT OF
CLOUD COVER THROUGH THE PERIOD BUT FEEL THAT BKN-OVC MVFR
CONDITIONS WILL BE PREVALENT AS CONTINUED SUBSIDENCE ACTS TO TRAP
MOISTURE AND ALLOW CLOUD BASES TO LOWER SOMEWHAT. SOME AREAS OF
CLEARING ARE POSSIBLE WHICH CAN BE HANDLED BY SHORT-TERM
AMENDMENTS. WINDS WILL BE GENERALLY LIGHT OVERNIGHT BUT SW FLOW
WILL INCREASE TOMORROW AS PRESSURE GRADIENT INCREASES...ESPECIALLY
FROM PTK NORTHWARD.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR PREVAILING CEILING BELOW 5000 FEET THROUGH THE PERIOD.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DT
LONG TERM....DRK/DE
MARINE.......DRK
AVIATION.....DT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
241 PM EST THU JAN 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 429 AM EST THU JAN 22 2015
A CLOUDY SKY COVERS ALL OF UPPER MICHIGAN EARLY THIS MORNING...AS
ABUNDANT LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE STRENGTHENING
SUBSIDENCE INVERSION (SEEN ON 00Z KINL SOUNDING) FROM THE HIGH
PRESSURE RIDGE OVER NORTHERN MINNESOTA. RAP ANALYSIS SHOWS A -12C
850MB THERMAL TROUGH SLIDING ACROSS CENTRAL/EASTERN LAKE SUPERIOR
EARLY THIS MORNING (ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
NORTHERN ONTARIO AND BRUSHING NORTHERN LAKE SUPERIOR) AND AIDING
WEAK LAKE EFFECT SNOW SHOWERS IN THE NORTHWEST WIND SNOW BELTS OVER
EASTERN UPPER MICHIGAN. OVERALL THESE ARE FAIRLY WEAK AND DISJOINTED
DUE TO THE MARGINAL DELTA-T VALUES AND WEAK LOW LEVEL LAPSE RATES.
THOSE MARGINAL FEATURES HAVE ALSO LEAD TO OCCASIONAL PERIODS OF
FREEZING DRIZZLE LAST EVENING OVER THE KEWEENAW AND ALSO OVER THE
NORTH CENTRAL THROUGH THE NIGHT. WILL INCLUDE A PATCHY FREEZING
DRIZZLE MENTION FOR THE NEXT COUPLE OF HOURS...BUT EXPECT THERE TO
BE LITTLE TO NO IMPACT WITH THE PRECIP BEING PREDOMINATELY SNOW.
UNDER THE CLOUDY SKIES...TEMPERATURES HAVE BEEN SLOW TO FALL THROUGH
THE NIGHT...WITH 3AM TEMPERATURES STILL IN THE LOWER 20S.
THE HIGH PRESSURE RIDGE OVER MINNESOTA WILL QUICKLY SLIDE EAST
ACROSS UPPER MICHIGAN TODAY...AS THE PARENT HIGH MOVES FROM THE
CENTRAL PLAINS TO THE OHIO RIVER VALLEY. THIS WILL LEAD TO STEADILY
BACKING LOW LEVEL WINDS THIS MORNING AND SHIFT ANY REMAINING LAKE
EFFECT SNOW OVER THE EAST OFFSHORE. THE BIGGEST QUESTION WITH THE
FORECAST TODAY IS WHAT WILL HAPPEN TO THE CLOUDS. MOST MODELS ARE
INDICATING THAT THE LOW CLOUDS WILL SCATTER OUT LATE THIS MORNING
AND INTO THE AFTERNOON. DO HAVE SOME CONCERN WITH THAT DUE TO THE
UPSTREAM OBS STILL INDICATING LOW CLOUDS INTO EASTERN MINNESOTA AND
WESTERN WISCONSIN...ALONG WITH THE STRENGTHENING SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH PRESSURE RIDGE MOVING THROUGH.
BUT WITH THE SOUTHWESTERLY FLOW INCREASING MIXING AND THE MOISTURE
LAYER BECOMING THIN...DID TREND THE FORECAST TOWARDS PARTLY CLOUDY.
THIS SITUATIONS ARE TRICKY...AS SOME AREAS WILL LIKELY CLEAR OUT
COMPLETELY (AIDED BY DOWNSLOPING SOUTHWESTERLY WINDS) WHILE THERE
COULD STILL BE POCKETS OF CLOUDY SKIES. AS THE LOW CLOUDS SCATTER
OUT...HIGH CLOUDS WILL BE THICKENING OVER THE AREA THIS
AFTERNOON/EVENING ASSOCIATED WITH THE APPROACHING CLIPPER SYSTEM.
THUS...WILL GRADUALLY INCREASE THE CLOUDS FROM THE NORTHWEST LATE
THIS AFTERNOON AND CONTINUE THROUGH THE NIGHT. LOWS WILL OCCUR THIS
EVENING AND THEN GRADUALLY WARM OVERNIGHT WITH THE INCREASING
SOUTHWESTERLY FLOW. THAT SOUTHWEST FLOW...WHICH WILL PRODUCE GALES
OVER WESTERN/CENTRAL LAKE SUPERIOR...IS EXPECTED TO LEAD TO GUSTY
CONDITIONS DEVELOPING OVER THE FAR WEST THIS AFTERNOON AND ACROSS
THE AREA TONIGHT. THINK THE STRONGEST GUSTS WILL REMAIN TOWARDS ISLE
ROYALE WHERE THE BEST PRESSURE FALLS ARE LOCATED...BUT STILL SHOULD
SEE SOME GUSTS TO 20-25KTS (AND 30KTS OVER THE KEWEENAW) TONIGHT.
AS THE COLD FRONT ASSOCIATED WITH THE CLIPPER SYSTEM APPROACHES LAKE
SUPERIOR TONIGHT...SHOULD SEE PRECIPITATION DROPPING SOUTHEAST
ACROSS WESTERN/CENTRAL LAKE SUPERIOR OVERNIGHT. SHOULD SEE IT
IMPACTING THE KEWEENAW PENINSULA BETWEEN 9-12Z. HAVE KEPT
PRECIPITATION AS SNOW FOR MOST LAND LOCATIONS THROUGH 12Z...BUT WITH
THE NAM INDICATING A WARM NOSE MOVING INTO WESTERN LAKE SUPERIOR
TOWARDS 12Z...DID ADD A MENTION OF FREEZING RAIN AND SLEET TO THAT
AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 241 PM EST THU JAN 22 2015
NAM SHOWS A DEEP 500 MB TROUGH OVER THE LOWER MISSISSIPPI RIVER
VALLEY 00Z SAT WITH A SHORTWAVE OVER THE UPPER GREAT LAKES. ANOTHER
SHORTWAVE DROPS INTO THE AREA LATE SAT NIGHT INTO SUNDAY WITH AN
ALBERTA CLIPPER TYPE SYSTEM. NAM SHOWS SOME DEEPER MOISTURE AND 850-
500 MB Q-VECTOR CONVERGENCE MOVING THROUGH ON SAT NIGHT INTO SUN
WITH BETTER MOISTURE AND DYNAMICS STAYING TO THE SOUTHWEST OF THE
AREA.
WILL NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST AND WILL KEEP
HIGHEST POPS ALONG THE WI BORDER AND IN THE SOUTH WITH THE ALBERTA
CLIPPER PASSING BY SAT NIGHT INTO SUNDAY. GOING TEMPERATURES LOOKED
GOOD AND DID NOT MAKE TOO MANY CHANGES TO THEM.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE LOWER
GREAT LAKES 12Z MON. THIS TROUGH DIGS ONTO THE EAST COAST 12Z TUE
WITH A RIDGE BUILDING INTO THE ROCKIES. UPPER PATTERN CHANGES LITTLE
12Z WED. ANOTHER SHORTWAVE DROPS INTO THE UPPER GREAT LAKES 12Z THU
WITH A SHOT OF COLD AIR COMING INTO THE AREA BY THE END OF THE
PERIOD. TEMPERATURES WILL STAY AROUND NORMAL THROUGH THE PERIOD AND
LAKE EFFECT SNOW SHOWERS WILL BE THE RULE WITH VERY LOW POPS THROUGH
THIS PERIOD. OVERALL...NO BIG CHANGES OR BIG EVENTS SEEN AND WILL BE
FAIRLY QUIET WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM EST THU JAN 22 2015
SKIES HAVE CLEARED TODAY AND WILL CONTINUE TO STAY MOSTLY CLEAR INTO
TONIGHT BEFORE A CLIPPER SYSTEM MOVES THROUGH THE AREA. HAVE WIND
SHEAR AT ALL SITES WITH THE STRONG LOW LEVEL WINDS AHEAD OF THE
SYSTEM. ALL SITES WILL SEE LOWERING CONDITIONS TONIGHT INTO FRI
MORNING. PRECIPITATION IS EXPECTED TO START AS SNOW BEFORE BECOMING
A WINTRY MIX OF PRECIPITATION.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EST THU JAN 22 2015
A HIGH PRESSURE RIDGE WILL QUICKLY SLIDE EAST ACROSS THE UPPER
GREAT LAKES REGION THIS MORNING...STEADILY BACKING WINDS TO THE
SOUTHWEST. AS THE PRESSURE GRADIENT TIGHTENS THIS AFTERNOON AND
TONIGHT AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH NORTHERN
MANITOBA AND NORTHERN ONTARIO...EXPECT SOUTHWESTERLY GALES OF
35-40KTS OVER PORTIONS OF WESTERN AND CENTRAL UPPER MICHIGAN. BASED
OFF THE STRENGTH OF THE WINDS JUST ABOVE THE SURFACE...WOULDN/T BE
SURPRISED TO SEE SOME 45KT GUSTS AT THE HIGHER PLATFORMS AROUND
ISLE ROYALE. THE GALE WARNING THAT IS IN PLACE LOOKS TO BE IN DECENT
SHAPE...ALTHOUGH DID EXPAND IT SOUTHWEST TO LSZ162. A COLD FRONT
ASSOCIATED WITH THE LOW WILL SWEEP SOUTHEAST ACROSS LAKE SUPERIOR
ON FRIDAY...SHIFTING THE WINDS TO THE NORTHWEST AND BRINGING AN END
TO THE GALES. BEHIND THE FRONT...EXPECT WINDS TO 25-30KTS BEFORE
SHIFTING MORE NORTHERLY BEHIND A SECONDARY TROUGH ON MOVING ACROSS
LAKE SUPERIOR ON SATURDAY. WINDS WILL DIMINISH BEHIND THE SECONDARY
TROUGH AS A HIGH PRESSURE RIDGE SHIFTS SOUTH INTO THE AREA
SATURDAY NIGHT. ANOTHER CLIPPER SYSTEM WILL MOVE OUT OF CANADA AND
THROUGH THE UPPER MISSISSIPPI VALLEY ON SATURDAY NIGHT AND THEN
SLIDE THROUGH WISCONSIN SUNDAY MORNING. THIS WILL KEEP WINDS UP TO
20KTS OUT OF THE NORTH-NORTHEAST. ANOTHER RIDGE WILL BUILD IN
BEHIND THIS CLIPPER AND KEEP WINDS 15KTS OR BELOW SUNDAY NIGHT INTO
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 PM EST /5 PM CST/ THIS EVENING TO 9 AM EST
/8 AM CST/ FRIDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...07
AVIATION...TITUS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1236 PM EST THU JAN 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 429 AM EST THU JAN 22 2015
A CLOUDY SKY COVERS ALL OF UPPER MICHIGAN EARLY THIS MORNING...AS
ABUNDANT LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE STRENGTHENING
SUBSIDENCE INVERSION (SEEN ON 00Z KINL SOUNDING) FROM THE HIGH
PRESSURE RIDGE OVER NORTHERN MINNESOTA. RAP ANALYSIS SHOWS A -12C
850MB THERMAL TROUGH SLIDING ACROSS CENTRAL/EASTERN LAKE SUPERIOR
EARLY THIS MORNING (ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
NORTHERN ONTARIO AND BRUSHING NORTHERN LAKE SUPERIOR) AND AIDING
WEAK LAKE EFFECT SNOW SHOWERS IN THE NORTHWEST WIND SNOW BELTS OVER
EASTERN UPPER MICHIGAN. OVERALL THESE ARE FAIRLY WEAK AND DISJOINTED
DUE TO THE MARGINAL DELTA-T VALUES AND WEAK LOW LEVEL LAPSE RATES.
THOSE MARGINAL FEATURES HAVE ALSO LEAD TO OCCASIONAL PERIODS OF
FREEZING DRIZZLE LAST EVENING OVER THE KEWEENAW AND ALSO OVER THE
NORTH CENTRAL THROUGH THE NIGHT. WILL INCLUDE A PATCHY FREEZING
DRIZZLE MENTION FOR THE NEXT COUPLE OF HOURS...BUT EXPECT THERE TO
BE LITTLE TO NO IMPACT WITH THE PRECIP BEING PREDOMINATELY SNOW.
UNDER THE CLOUDY SKIES...TEMPERATURES HAVE BEEN SLOW TO FALL THROUGH
THE NIGHT...WITH 3AM TEMPERATURES STILL IN THE LOWER 20S.
THE HIGH PRESSURE RIDGE OVER MINNESOTA WILL QUICKLY SLIDE EAST
ACROSS UPPER MICHIGAN TODAY...AS THE PARENT HIGH MOVES FROM THE
CENTRAL PLAINS TO THE OHIO RIVER VALLEY. THIS WILL LEAD TO STEADILY
BACKING LOW LEVEL WINDS THIS MORNING AND SHIFT ANY REMAINING LAKE
EFFECT SNOW OVER THE EAST OFFSHORE. THE BIGGEST QUESTION WITH THE
FORECAST TODAY IS WHAT WILL HAPPEN TO THE CLOUDS. MOST MODELS ARE
INDICATING THAT THE LOW CLOUDS WILL SCATTER OUT LATE THIS MORNING
AND INTO THE AFTERNOON. DO HAVE SOME CONCERN WITH THAT DUE TO THE
UPSTREAM OBS STILL INDICATING LOW CLOUDS INTO EASTERN MINNESOTA AND
WESTERN WISCONSIN...ALONG WITH THE STRENGTHENING SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH PRESSURE RIDGE MOVING THROUGH.
BUT WITH THE SOUTHWESTERLY FLOW INCREASING MIXING AND THE MOISTURE
LAYER BECOMING THIN...DID TREND THE FORECAST TOWARDS PARTLY CLOUDY.
THIS SITUATIONS ARE TRICKY...AS SOME AREAS WILL LIKELY CLEAR OUT
COMPLETELY (AIDED BY DOWNSLOPING SOUTHWESTERLY WINDS) WHILE THERE
COULD STILL BE POCKETS OF CLOUDY SKIES. AS THE LOW CLOUDS SCATTER
OUT...HIGH CLOUDS WILL BE THICKENING OVER THE AREA THIS
AFTERNOON/EVENING ASSOCIATED WITH THE APPROACHING CLIPPER SYSTEM.
THUS...WILL GRADUALLY INCREASE THE CLOUDS FROM THE NORTHWEST LATE
THIS AFTERNOON AND CONTINUE THROUGH THE NIGHT. LOWS WILL OCCUR THIS
EVENING AND THEN GRADUALLY WARM OVERNIGHT WITH THE INCREASING
SOUTHWESTERLY FLOW. THAT SOUTHWEST FLOW...WHICH WILL PRODUCE GALES
OVER WESTERN/CENTRAL LAKE SUPERIOR...IS EXPECTED TO LEAD TO GUSTY
CONDITIONS DEVELOPING OVER THE FAR WEST THIS AFTERNOON AND ACROSS
THE AREA TONIGHT. THINK THE STRONGEST GUSTS WILL REMAIN TOWARDS ISLE
ROYALE WHERE THE BEST PRESSURE FALLS ARE LOCATED...BUT STILL SHOULD
SEE SOME GUSTS TO 20-25KTS (AND 30KTS OVER THE KEWEENAW) TONIGHT.
AS THE COLD FRONT ASSOCIATED WITH THE CLIPPER SYSTEM APPROACHES LAKE
SUPERIOR TONIGHT...SHOULD SEE PRECIPITATION DROPPING SOUTHEAST
ACROSS WESTERN/CENTRAL LAKE SUPERIOR OVERNIGHT. SHOULD SEE IT
IMPACTING THE KEWEENAW PENINSULA BETWEEN 9-12Z. HAVE KEPT
PRECIPITATION AS SNOW FOR MOST LAND LOCATIONS THROUGH 12Z...BUT WITH
THE NAM INDICATING A WARM NOSE MOVING INTO WESTERN LAKE SUPERIOR
TOWARDS 12Z...DID ADD A MENTION OF FREEZING RAIN AND SLEET TO THAT
AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 524 AM EST THU JAN 22 2015
A PERSISTENT RIDGE OVER THE WRN CONUS WILL MAINTAIN NW MID/UPPER
LEVEL FLOW ACROSS THE NRN GREAT LAKES THROUGH THE MIDDLE OF NEXT
WEEK. THIS WILL BRING A SERIES OF CLIPPERS INTO THE REGION. IT
APPEARS AT THIS TIME ANY LES FROM THESE CLIPPERS WOULD BE LIGHT AS
ONLY MARGINAL INSTABILITY IS EXPECTED WITH THE COLDEST AIR
REMAINING OVER NE CANADA.
FRIDAY...MODELS FCST QVECTOR CONV AHEAD OF A SHORTWAVE TROUGH ALONG
WITH 280K-290K ISENTROPIC LIFT SHOULD BE STRONG ENOUGH TO SQUEEZE
OUT SOME LIGHT PCPN INTO PORTIONS OF UPPER MI. THERE IS STILL SOME
UNCERTAINTY WITH THE PCPN AMOUNTS/PLACEMENT. HOWEVER...THE STRONGER
FORCING IS EXPECTED TO MOVE THROUGH DURING THE MORNING WITH DRYING
DURING THE AFTERNOON. THE NAM...WHICH OFTEN PERFORMS BETTER WITH
DEVELOPING WARM LAYERS ALOFT...SUGGESTS THAT THE PCPN OVER THE WEST
HALF COULD BE MIXED WITH FREEZING RAIN OR SLEET AS THE MAX TEMP
ALOFT CLIMBS TO AROUND 3C(NEAR 900 MB). THE POSITION OF THE WARM
NOSE WOULD BRING THE BEST CHANCE FOR ANY ICING OVER MAINLY JUST THE
FAR WEST. OTHERWISE...TEMPS WILL CLIMB WELL ABOVE NORMAL WITH MAX
READINGS INTO THE MID 30S.
FRI NIGHT... COLDER AIR WILL ONLY GRADUALLY MOVE IN FRI NIGHT WITH
NW WINDS BEHIND A SFC TROUGH AS 850 MB TEMPS DROP TO -6C TO -8C BY
12Z/SAT. SOME LIGHT LAKE ENHANCED SNOW IS POSSIBLE FOR NW FLOW
FAVORED LOCATIONS AS A WEAK SHORTWAVE MOVES THROUGH WITH DEEPER
MOISTURE OVER THE AREA. OTHERWISE...WRLY FLOW OF PACIFIC AIR BEHIND
THE SFC TROUGH WILL KEEP TEMPS FROM DROPPING OFF MUCH WITH MANY
LOCATIONS NOT DROPPING MUCH BELOW 30F...ESPECIALLY FOR DOWNSLOPE
FLOW LOCATIONS.
SAT...MARGINALLY COLD AIR WITH 850 MB TEMPS FALLING TO -10C TO
-12C WILL MOVE IN AS A RIDGE BUILDS INTO THE WRN LAKES. DIMINISHING
LOW LEVEL WINDS BECOMING MORE ANTICYCLONIC AND NRLY WITH TIME WILL
ALSO LIMIT POTENTIAL FOR LES ACCUMULATIONS CONSISTENT WITH ONLY
CHANCE POPS.
SAT NIGHT AND SUN...THERE IS STILL SOME MODEL UNCERTAINTY WITH THE
TRACK OF THE NEXT CLIPPER SYSTEM. THE ECMWF REMAINS FARTHEST TO THE
WEST AND SOUTH WITH LITTLE PCPN INTO UPPER MICHIGAN WHILE THE
CANADIAN BRINGS THE HEAVIER PCPN THROUGH THE CWA. SOME AREAS IN THE
REGION COULD SEE SNOWFALL INTO THE 1 TO 4 INCH RANGE WITH THE SYSTEM.
THE GFS REPRESENTS A COMPROMISE KEEPING THEPCPN OVER WEST UPPER
MICHIGAN. WILL CONTINUE ALONG WITH CONSENSUS FCST WHICH KEEPS CHANCE
POPS ACROSS THE WEST.
MON INTO WED...ANOTHER CLIPPER SYSTEM IS EXPECTED TO MOVE INTO THE
REGION BY LATE MON OR MON NIGHT BUT THE MODELS HAVE TRENDED WEAKER
WITH THIS SHRTWV WITH ONLY LIGHT PCPN REMAINING WEST OF UPPER MI.
SFC RIDGING INTO THE AREA WITH LIGHT WINDS WILL ALSO NOT BE
FAVORABLE FOR LES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM EST THU JAN 22 2015
SKIES HAVE CLEARED TODAY AND WILL CONTINUE TO STAY MOSTLY CLEAR INTO
TONIGHT BEFORE A CLIPPER SYSTEM MOVES THROUGH THE AREA. HAVE WIND
SHEAR AT ALL SITES WITH THE STRONG LOW LEVEL WINDS AHEAD OF THE
SYSTEM. ALL SITES WILL SEE LOWERING CONDITIONS TONIGHT INTO FRI
MORNING. PRECIPITATION IS EXPECTED TO START AS SNOW BEFORE BECOMING
A WINTRY MIX OF PRECIPITATION.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EST THU JAN 22 2015
A HIGH PRESSURE RIDGE WILL QUICKLY SLIDE EAST ACROSS THE UPPER
GREAT LAKES REGION THIS MORNING...STEADILY BACKING WINDS TO THE
SOUTHWEST. AS THE PRESSURE GRADIENT TIGHTENS THIS AFTERNOON AND
TONIGHT AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH NORTHERN
MANITOBA AND NORTHERN ONTARIO...EXPECT SOUTHWESTERLY GALES OF
35-40KTS OVER PORTIONS OF WESTERN AND CENTRAL UPPER MICHIGAN. BASED
OFF THE STRENGTH OF THE WINDS JUST ABOVE THE SURFACE...WOULDN/T BE
SURPRISED TO SEE SOME 45KT GUSTS AT THE HIGHER PLATFORMS AROUND
ISLE ROYALE. THE GALE WARNING THAT IS IN PLACE LOOKS TO BE IN DECENT
SHAPE...ALTHOUGH DID EXPAND IT SOUTHWEST TO LSZ162. A COLD FRONT
ASSOCIATED WITH THE LOW WILL SWEEP SOUTHEAST ACROSS LAKE SUPERIOR
ON FRIDAY...SHIFTING THE WINDS TO THE NORTHWEST AND BRINGING AN END
TO THE GALES. BEHIND THE FRONT...EXPECT WINDS TO 25-30KTS BEFORE
SHIFTING MORE NORTHERLY BEHIND A SECONDARY TROUGH ON MOVING ACROSS
LAKE SUPERIOR ON SATURDAY. WINDS WILL DIMINISH BEHIND THE SECONDARY
TROUGH AS A HIGH PRESSURE RIDGE SHIFTS SOUTH INTO THE AREA
SATURDAY NIGHT. ANOTHER CLIPPER SYSTEM WILL MOVE OUT OF CANADA AND
THROUGH THE UPPER MISSISSIPPI VALLEY ON SATURDAY NIGHT AND THEN
SLIDE THROUGH WISCONSIN SUNDAY MORNING. THIS WILL KEEP WINDS UP TO
20KTS OUT OF THE NORTH-NORTHEAST. ANOTHER RIDGE WILL BUILD IN
BEHIND THIS CLIPPER AND KEEP WINDS 15KTS OR BELOW SUNDAY NIGHT INTO
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 6 PM EST /5 PM CST/ THIS EVENING TO 9 AM EST
/8 AM CST/ FRIDAY FOR LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...JLB
AVIATION...TITUS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1219 PM CST THU JAN 22 2015
.UPDATE...
ISSUED AT 1026 AM CST THU JAN 22 2015
PATCH OF STRATUS MOVING NORTHEAST AS EXPECTED EXITING FARGO AND
MOVING THROUGH MAHNOMEN AND FOSSTON. OTHERWISE CIRRUS INCREASING
FROM THE NORTHWEST IN WARM ADV PATTERN. EXPECT QUITE RISE IN TEMPS
TODAY...LATEST TO SEE IT IN THE RED RIVER VALLEY FLOOR. WILL KEEP
PREV THINKING OF SOME 20S FAR EAST AND SOUTHEAST AND MID 30S FAR
WEST. SOUTHWEST WINDS GUSTY AT TIMES....ESP NW FCST AREA...BUT
SHOULD REMAIN BLO ADVISORY. DID UPDATE WEATHER TRENDS FOR THE
OVERNIGHT WITH NEXT WEAK SHORTWAVE. LOOKING AT GFS/NAM 12Z 925 MB
TEMOS FEEL WITH A WEST TO SOUTHWEST WIND TONIGHT TEMPS WILL BE
HARD TO FALL MUCH AND USING 12Z GFS FOR UPPER LEVEL TEMPS WILL
BRING MORE LIQUID THAN FROZEN LIQUID.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 345 AM CST THU JAN 22 2015
PRECIP CHANCES AND TYPE WILL AGAIN BE THE PRIMARY CONCERN FOR THE
SHORT TERM.
NORTHWESTERLY FLOW ALOFT WILL CONTINUE...WITH A SFC LOW
STRENGTHENING OVER SOUTHERN CANADA IN RESPONSE TO A SHORTWAVE
TROUGH MOVING THROUGH THAT AREA. THIS WILL INCREASE THE PRESSURE
GRADIENT OVER THE CWA...WITH SOUTHWESTERLY WINDS PICKING UP TO
JUST BELOW ADVISORY CRITERA. THE SOUTHWEST WINDS WILL ALSO BRING
A WARMER AIR MASS BACK INTO THE REGION. WE SHOULD AGAIN GET INTO
THE 20S AND 30S EVEN WITH A COOL START THIS MORNING AND INCREASING
CLOUDS.
TONIGHT...THERE WILL BE A FAIRLY SIGNIFICANT SHORTWAVE DIGGING
FROM MANITOBA INTO NORTHERN ND. THE MODELS ARE A LITTLE MORE
CONSISTENT TODAY ON PUTTING OUT SOME PRECIP TONIGHT AND INTO
TOMORROW MORNING AS THE SHORTWAVE MOVES THROUGH THE CWA. THE RAP IN
FACT HAS SOME PRECIP MOVING IN AS SOON AS LATE AFTERNOON. THINK
THIS IS A BIT OVERDONE GIVEN THE TIME IT TAKES TO SATURATE AND
WILL KEEP POPS OUT UNTIL AFTER 00Z FRIDAY. HAVE SOME 20-30 POPS
MOVING THROUGH TONIGHT BEFORE EXITING TOMORROW MORNING. WHILE THE
AMOUNTS WILL BE LIGHT...THERE WILL BE A VERY STRONG WARM LAYER
ALOFT MOVING IN WITH THE SOUTHWESTERLY WINDS. SFC TEMPS IN THE
EVENING MAY ACTUALLY STILL BE ABOVE FREEZING BUT AS THE BOUNDARY
LAYER COOLS OFF SOME FREEZING RAIN IS DEFINITELY POSSIBLE. TOO
MUCH UNCERTAINTY FOR ANY HEADLINES AT THIS POINT BUT WILL KEEP AN
EYE FOR SOME LIGHT ICE ACCUMULATIONS.
FRIDAY...THE UPPER SHORTWAVE WILL DIG DOWN INTO MN...ALLOWING THE
SFC TROUGH TO MOVE EAST AND WINDS ACROSS THE CWA SHIFT TO THE WEST
AND NORTHWEST ON THE BACKSIDE OF THE LOW. WITH THE WEST WINDS
THINK WE WILL SEE SOME REDUCTIONS IN CLOUDS...AND WITH 850MB TEMPS
STILL WELL ABOVE ZERO C...FRIDAY LOOKS TO BE VERY MILD WITH HIGHS
IN THE 30S AND SOME SPOTS NEAR THE 40 MARK.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU JAN 22 2015
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE MODELS ALL BRING A
FAIRLY SIGNIFICANT SHORTWAVE DOWN INTO THE REGION...BUT STRUGGLE
ON TIMING AND STRENGTH. WARM AIR ADVECTION WILL CONTINUE THROUGH
FRIDAY NIGHT AHEAD OF THE SYSTEM SO THERE WILL BE A CONTINUED
CHANCE FOR SOME MIXED PRECIP WHEN IT MOVES IN. THE ECMWF IS FASTER
THAN THE OTHER DETERMINISTIC MODELS...AND THE 00Z RUN HAS COME IN
FURTHER WEST WITH SIGNIFICANT PRECIP. THIS PUTS IT MORE SIMILAR TO
THE NAM WHICH IS FURTHEREAST WEST WITH DEFORMATION BAND PRECIP AND
IS THE STRONGEST WITH QPF. THE GFS ON THE OTHER HAND...HAS THE
MAIN PRECIP OVER THE FAR EASTERN COUNTIES. WITH HIGH UNCERTAINTY
WILL CONTINUE TO KEEP THE BLENDED SOLUTION...WHICH HAS THE HIGHEST
POPS FOR SATURDAY NIGHT. WITH FAIRLY WARM TEMPS CONTINUING INTO
SATURDAY THERE COULD BE SOME MIXED PRECIP...SO WENT WITH SOME
LIGHT ICING AND A FEW INCHES OF SNOW...MAINLY OVER THE
NORTHEASTERN COUNTIES.
SUNDAY THROUGH WEDNESDAY...LONG WAVE RIDGE ESSENTIALLY REMAINS OVER
WESTERN NORTH AMERICA...PERHAPS RETROGRADES A BIT TROUGH THE
PERIOD. LONG WAVE TROUGH REMAINS OVER EASTERN NORTH AMERICA.
PATTERN INTENSIFIES THROUGH DAY 5 THEN DE AMPLIFIES THEREAFTER.
PATTERN REMAINS THE SAME THROUGH THE PERIOD WITH PROGRESSIVE SHORT
WAVES MOVING THROUGH THE FLOW. SHORT WAVE RIDGE MOVES EAST OVER
THE NORTHERN PLAINS ON WED. THE ECMWF WAS FASTER THAN THE GFS
THROUGH THE PERIOD. GFS AND ECMWF HAVE TRENDED FASTER OVER THE
LAST COUPLE RUNS. WILL PREFER THE ECMWF.
HIGH TEMPS HAVE BEEN INCREASED A DEGREE OR SO FOR SUN AND INCREASED
TWO TO FOUR DEGREES FOR MON THROUGH WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1218 PM CST THU JAN 22 2015
GUSTY SW WINDS THIS AFTERNOON WILL CONTINUE INTO THE EVENING AND
POSSIBLY OVERNIGHT. MAY SEE SOME LIGHT FZRA THIS EVENING AT GFK AND
TVF IN THE 0 TO 6Z TIME FRAME THOUGH CONFIDENCE IS VERY POOR SO HAVE
EXCLUDED FROM TAF CURRENTLY. BIGGEST UNCERTAINTY IS DRY LEVEL UNDER
8KFT AND SFC TEMPS...MAY JUST BE RAIN IF PRECIP DOES OCCUR. FARTHER
EAST AT BJI DID MENTION -SN OVERNIGHT AS SATURATION AND COVERAGE
INCREASE LEADING TO HIGHER CONFIDENCE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...JK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1029 AM CST THU JAN 22 2015
.UPDATE...
ISSUED AT 1026 AM CST THU JAN 22 2015
PATCH OF STRATUS MOVING NORTHEAST AS EXPECTED EXITING FARGO AND
MOVING THROUGH MAHNOMEN AND FOSSTON. OTHERWISE CIRRUS INCREASING
FROM THE NORTHWEST IN WARM ADV PATTERN. EXPECT QUITE RISE IN TEMPS
TODAY...LATEST TO SEE IT IN THE RED RIVER VALLEY FLOOR. WILL KEEP
PREV THINKING OF SOME 20S FAR EAST AND SOUTHEAST AND MID 30S FAR
WEST. SOUTHWEST WINDS GUSTY AT TIMES....ESP NW FCST AREA...BUT
SHOULD REMAIN BLO ADVISORY. DID UPDATE WEATHER TRENDS FOR THE
OVERNIGHT WITH NEXT WEAK SHORTWAVE. LOOKING AT GFS/NAM 12Z 925 MB
TEMOS FEEL WITH A WEST TO SOUTHWEST WIND TONIGHT TEMPS WILL BE
HARD TO FALL MUCH AND USING 12Z GFS FOR UPPER LEVEL TEMPS WILL
BRING MORE LIQUID THAN FROZEN LIQUID.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 345 AM CST THU JAN 22 2015
PRECIP CHANCES AND TYPE WILL AGAIN BE THE PRIMARY CONCERN FOR THE
SHORT TERM.
NORTHWESTERLY FLOW ALOFT WILL CONTINUE...WITH A SFC LOW
STRENGTHENING OVER SOUTHERN CANADA IN RESPONSE TO A SHORTWAVE
TROUGH MOVING THROUGH THAT AREA. THIS WILL INCREASE THE PRESSURE
GRADIENT OVER THE CWA...WITH SOUTHWESTERLY WINDS PICKING UP TO
JUST BELOW ADVISORY CRITERA. THE SOUTHWEST WINDS WILL ALSO BRING
A WARMER AIR MASS BACK INTO THE REGION. WE SHOULD AGAIN GET INTO
THE 20S AND 30S EVEN WITH A COOL START THIS MORNING AND INCREASING
CLOUDS.
TONIGHT...THERE WILL BE A FAIRLY SIGNIFICANT SHORTWAVE DIGGING
FROM MANITOBA INTO NORTHERN ND. THE MODELS ARE A LITTLE MORE
CONSISTENT TODAY ON PUTTING OUT SOME PRECIP TONIGHT AND INTO
TOMORROW MORNING AS THE SHORTWAVE MOVES THROUGH THE CWA. THE RAP IN
FACT HAS SOME PRECIP MOVING IN AS SOON AS LATE AFTERNOON. THINK
THIS IS A BIT OVERDONE GIVEN THE TIME IT TAKES TO SATURATE AND
WILL KEEP POPS OUT UNTIL AFTER 00Z FRIDAY. HAVE SOME 20-30 POPS
MOVING THROUGH TONIGHT BEFORE EXITING TOMORROW MORNING. WHILE THE
AMOUNTS WILL BE LIGHT...THERE WILL BE A VERY STRONG WARM LAYER
ALOFT MOVING IN WITH THE SOUTHWESTERLY WINDS. SFC TEMPS IN THE
EVENING MAY ACTUALLY STILL BE ABOVE FREEZING BUT AS THE BOUNDARY
LAYER COOLS OFF SOME FREEZING RAIN IS DEFINITELY POSSIBLE. TOO
MUCH UNCERTAINTY FOR ANY HEADLINES AT THIS POINT BUT WILL KEEP AN
EYE FOR SOME LIGHT ICE ACCUMULATIONS.
FRIDAY...THE UPPER SHORTWAVE WILL DIG DOWN INTO MN...ALLOWING THE
SFC TROUGH TO MOVE EAST AND WINDS ACROSS THE CWA SHIFT TO THE WEST
AND NORTHWEST ON THE BACKSIDE OF THE LOW. WITH THE WEST WINDS
THINK WE WILL SEE SOME REDUCTIONS IN CLOUDS...AND WITH 850MB TEMPS
STILL WELL ABOVE ZERO C...FRIDAY LOOKS TO BE VERY MILD WITH HIGHS
IN THE 30S AND SOME SPOTS NEAR THE 40 MARK.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU JAN 22 2015
FRIDAY NIGHT THROUGH SATURDAY NIGHT...THE MODELS ALL BRING A
FAIRLY SIGNIFICANT SHORTWAVE DOWN INTO THE REGION...BUT STRUGGLE
ON TIMING AND STRENGTH. WARM AIR ADVECTION WILL CONTINUE THROUGH
FRIDAY NIGHT AHEAD OF THE SYSTEM SO THERE WILL BE A CONTINUED
CHANCE FOR SOME MIXED PRECIP WHEN IT MOVES IN. THE ECMWF IS FASTER
THAN THE OTHER DETERMINISTIC MODELS...AND THE 00Z RUN HAS COME IN
FURTHER WEST WITH SIGNIFICANT PRECIP. THIS PUTS IT MORE SIMILAR TO
THE NAM WHICH IS FURTHEREAST WEST WITH DEFORMATION BAND PRECIP AND
IS THE STRONGEST WITH QPF. THE GFS ON THE OTHER HAND...HAS THE
MAIN PRECIP OVER THE FAR EASTERN COUNTIES. WITH HIGH UNCERTAINTY
WILL CONTINUE TO KEEP THE BLENDED SOLUTION...WHICH HAS THE HIGHEST
POPS FOR SATURDAY NIGHT. WITH FAIRLY WARM TEMPS CONTINUING INTO
SATURDAY THERE COULD BE SOME MIXED PRECIP...SO WENT WITH SOME
LIGHT ICING AND A FEW INCHES OF SNOW...MAINLY OVER THE
NORTHEASTERN COUNTIES.
SUNDAY THROUGH WEDNESDAY...LONG WAVE RIDGE ESSENTIALLY REMAINS OVER
WESTERN NORTH AMERICA...PERHAPS RETROGRADES A BIT TROUGH THE
PERIOD. LONG WAVE TROUGH REMAINS OVER EASTERN NORTH AMERICA.
PATTERN INTENSIFIES THROUGH DAY 5 THEN DE AMPLIFIES THEREAFTER.
PATTERN REMAINS THE SAME THROUGH THE PERIOD WITH PROGRESSIVE SHORT
WAVES MOVING THROUGH THE FLOW. SHORT WAVE RIDGE MOVES EAST OVER
THE NORTHERN PLAINS ON WED. THE ECMWF WAS FASTER THAN THE GFS
THROUGH THE PERIOD. GFS AND ECMWF HAVE TRENDED FASTER OVER THE
LAST COUPLE RUNS. WILL PREFER THE ECMWF.
HIGH TEMPS HAVE BEEN INCREASED A DEGREE OR SO FOR SUN AND INCREASED
TWO TO FOUR DEGREES FOR MON THROUGH WED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 646 AM CST THU JAN 22 2015
SOME MVFR/IFR STRATUS HAS MOVED INTO SOUTHEASTERN ND AND MAY
AFFECT THE KFAR FOR THE NEXT FEW HOURS...BUT OTHERWISE CONDITIONS
ARE VFR. THERE WILL BE INCREASING HIGH AND MID CLOUDS...BUT THE
MAIN CONCERN WILL BE WINDS. SOUTHWEST WINDS WILL CLIMB TO THE 15
TO 20 KT RANGE WITH GUSTS APPROACHING 30 KTS AT SOME SITES. WINDS
WILL DECREASE A BIT TONIGHT AND SHIFT TO THE WEST BUT WILL STILL
BE ABOVE 12 KTS. THE MODELS TRY AND BRING IN SOME STRATUS DURING
THE LATER PART OF THE PERIOD. FOR NOW JUST INCLUDED KBJI WITH MVFR
CONDITIONS AND KEEP EVERYWHERE ELSE VFR.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPPES
AVIATION...JR
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
306 PM CST THU JAN 22 2015
.SHORT TERM...
WATER VAPOR IMAGERY SHOWING A VIGOROUS STORM SYSTEM CONTINUING TO
MOVE SEWD THROUGH SRN NEW MEXICO. THE POSITIVELY TILTED TROUGH THAT
EXTENDS NEWD FROM THE BASE OF THE TROUGH /FROM SRN NEW MEXICO
THROUGH THE TEXAS PANHANDLE/ PRODUCING THE LAST BIT OF LIFT
ACROSS THE WRN AND CNTL PARTS OF THE FCST AREA. 18Z WRF-NAM AND
MORNING RUNS OF THE HRRR IN PRETTY GOOD AGREEMENT IN SHIFTING
LIGHT TO OCCASIONALLY MODERATE SNOWFALL SEWD IN TIME. SOME MODEST
ACCUMULATIONS GENERALLY LESS THAN 1/2 INCH REMAIN POSSIBLE WITH
THE HEAVIEST SNOW...BUT IT WILL BE MOVING INTO AN AREA THAT HAS
BEEN AT OR ABOVE FREEZING THIS AFTN. DO NOT ANTICIPATE ANY
PROBLEMS ASSOCIATED WITH THE SNOWFALL FROM LUBBOCK TO THE EAST AND
SOUTHEAST...SO CURRENT CONFIGURATION OF THE WINTER WEATHER
ADVISORY SHOULD SUFFICE.
PRECIP LIKELY TO COME TO AN END BY MIDNIGHT WITH POSSIBLE EXCEPTION
OF THE FAR SRN PART OF THE FCST AREA WHERE WILL KEEP SLIGHT CHC TO
LOW END CHANCE MENTION ATTM.
SOME CLEARING EXPECTED FROM NW TO SE BY SUNRISE. THAT CLEARING
ACROSS THE NWRN ZONES COMBINED WITH SNOW COVER SHOULD ALLOW TEMPS
THERE TO DROP TO OR BELOW COLD END OF MOS GUIDANCE WHILE FARTHER
EAST LOW TEMPS NEAR A MOS BLEND MORE LIKELY. HIGH TEMPS FRIDAY
WILL BE TRICKY. INSOLATION AND MODEST WEST WIND TO BE COUNTERACTED
ACROSS THE NWRN THIRD OF THE FCST AREA BY THE SNOW FIELD. WILL
CONTINUE TO UNDERCUT GUIDANCE THERE AND LEAN CLOSER TO MOS FURTHER
TO THE EAST AND SOUTHEAST.
&&
.LONG TERM...
NORTHWEST FLOW WILL MOVE OVERHEAD FOR THE WEEKEND INTO NEXT WEEK
LEADING TO DRY CONDITIONS AND A STEADY WARMUP UNDERNEATH INCREASING
HEIGHTS/THICKNESSES ALOFT WITH RIDGING DOMINATING THE WESTERN CONUS
AND TROUGHING ENCOMPASSING POINTS EAST. ASIDE FROM SOME SCATTERED
CIRRUS SATURDAY...OWING TO ENERGY ALOFT BEING SHUNTED SOUTHWEST
TOWARD THE GULF OF CALIFORNIA WITH DEVELOPMENT OF A CUTOFF
LOW...MOSTLY SUNNY SKIES WILL BE IN THE OFFING. TEMPERATURES SHOULD
GRADUALLY WARM INTO THE 40S/50S SATURDAY AND NEAR 50 IN VICINITY OF
LINGERING SNOWPACK IN THE FAR SOUTHWEST PANHANDLE TO MID 60S IN THE
ROLLING PLAINS SUNDAY. A BACKDOOR FRONT MAY BRING A NORTHERLY WIND
SHIFT BY MONDAY AS A DISTURBANCE DIVES ACROSS THE UPPER
MIDWEST/GREAT LAKES INTO THE OHIO VALLEY...BUT NO CHANGE IN AIRMASS
LOOKS TO BE IN STORE LOCALLY. FURTHER WARMING WELL INTO THE 60S
SHOULD OCCUR THROUGH THE WEEK AS UPPER RIDGING APPROACHES FROM THE
WEST. MAY SEE A COOLDOWN BACK TO NEAR AVERAGE BY MID-LATE WEEK IF
PACIFIC MOISTURE CAN ADVECT NORTHEAST AHEAD OF A SERIES OF PROGGED
DISTURBANCES.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 8 36 14 41 / 20 0 0 0
TULIA 12 38 22 43 / 30 0 0 0
PLAINVIEW 15 37 23 46 / 30 0 0 0
LEVELLAND 14 38 22 47 / 50 0 0 0
LUBBOCK 16 39 23 48 / 50 0 0 0
DENVER CITY 19 38 25 49 / 60 10 0 0
BROWNFIELD 18 40 23 49 / 60 10 0 0
CHILDRESS 23 45 29 55 / 30 0 0 0
SPUR 22 43 27 53 / 70 10 0 0
ASPERMONT 27 47 28 55 / 70 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR TXZ021-
022-027-028-033-034-039>042.
&&
$$
07/31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1021 AM CST THU JAN 22 2015
.DISCUSSION...
A NEARLY STATIONARY WARM FRONT HAS WORKED ITS WAY FROM THE COAST
TO NEAR A KBPT TO KVCT LINE AT 9 AM. THE RAP13 AND HRRR BOTH WERE
DOING A GOOD JOB WITH THE RAINFALL THIS MORNING...AND BOTH
FORECAST THE MODERATE RAINFALL IN THE NORTH TO SLOWLY LESSEN IN
INTENSITY AS THE MODERATE RAINFALL AREA INCREASES TOWARD THE
COAST.
MADE SOME CHANGES TO THE TEMPERATURES ACROSS THE AREA. THE FRONT
WILL SLOWLY WAFFLE A BIT THIS MORNING BEFORE MOVING BACK TOWARD
THE COAST THIS AFTERNOON. A SURFACE LOW OVER SOUTH TEXAS WILL
PROBABLY MOVE INTO THE SOUTHERN COUNTIES AND ADD A BIT OF
COMPLEXITY TO THE FRONTAL MOVEMENT.
40
&&
.PREV DISCUSSION... /ISSUED 557 AM CST THU JAN 22 2015/
AVIATION...
MAINLY MVFR/IFR CEILINGS AND VISIBILITIES CAN BE EXPECTED TO DEVELOP
TODAY AS RAIN WITH EMBEDDED SHOWERS AND THUNDERSTORMS MOVE GENERALLY
TO THE EAST AND NORTHEAST ACROSS THE AREA. THE BULK OF RAIN WILL MOVE
OFF TO OUR EAST LATER THIS AFTERNOON AND ON THROUGH THE EARLY EVENING
HOURS...HOWEVER SOME ACTIVITY ALONG WITH MVFR/IFR CEILINGS WILL LINGER
INTO THE OVERNIGHT HOURS. ELEVATED AND POTENTIALLY VERY GUSTY EAST TO
NORTHEAST WINDS WILL PREVAIL AS SURFACE LOW PRESSURE MOVES UP ALONG
THE COAST THIS AFTERNOON. WINDS BECOME MORE OUT OF THE NORTH TONIGHT
AS THE LOW EDGES OFF TO THE EAST AND A COLD FRONT MOVES OFF THE COAST.
42
PREV DISCUSSION... /ISSUED 353 AM CST THU JAN 22 2015/
DISCUSSION...
WIDESPREAD RAINFALL IS ONGOING ACROSS MUCH OF THE STATE THIS
MORNING AS SOUTHWESTERLY FLOW ALOFT IS CAUSING OVERRUNNING ACROSS
THE COOLER AIRMASS IN PLACE BEHIND THE FRONT THAT MOVED TO THE
COAST YESTERDAY. A FEW THUNDERSTORMS ARE ONGOING ACROSS CENTRAL
TEXAS IN ASSOCIATION WITH A WEAK SHORTWAVE EMBEDDED IN THE UPPER
FLOW. RAINFALL COVERAGE WILL INCREASE ACROSS THE REGION LATER THIS
MORNING WITH THE APPROACH OF A LARGE UPPER LEVEL TROUGH AND THE
DEVELOPMENT OF A COASTAL TROUGH AHEAD OF IT. SOME ISOLATED
THUNDERSTORMS WILL BE POSSIBLE DUE TO SOME ELEVATED INSTABILITY.
WINDS WILL PICK UP ACROSS THE REGION AS THE SURFACE TROUGH
STRENGTHENS AND APPROACHES FROM THE WEST. ALONG THE COAST WINDS
WILL BE QUITE BREEZY THIS EVENING WITH SUSTAINED WINDS BETWEEN 20
AND 30 MPH POSSIBLE. WILL ISSUE A WIND ADVISORY FOR THE COASTAL
TIER OF COUNTIES THIS EVENING TO ACCOUNT FOR THIS...ALTHOUGH FAR
INLAND REACHES OF BRAZORIA AND MATAGORDA COUNTIES MAY SEE WINDS
REMAIN JUST BELOW ADVISORY CRITERIA.
BULK OF THE RAIN WILL EXIT TO THE EAST LATE THIS EVENING BUT
SCATTERED SHOWERS WILL LINGER ACROSS THE REGION THROUGH FRIDAY
BEFORE THE TROUGH AXIS MOVES OFF TO OUR EAST. RAINFALL TOTALS FOR
THE EVENT WILL AVERAGE AROUND 1-2 INCHES WITH SOME ISOLATED TOTALS
OF AROUND 3 INCHES. DRIER CONDITIONS ARE EXPECTED BEGINNING
SATURDAY AND EXTENDING INTO THE MIDDLE OF NEXT WEEK AS WINDS ALOFT
BECOME NORTHWESTERLY AND THEN UPPER RIDGING ESTABLISHES ITSELF
ACROSS THE STATE. EXPECT MOSTLY SUNNY SKIES AND SEASONABLE LOW
TEMPERATURES WITH SLIGHTLY ABOVE NORMAL AFTERNOON HIGHS. 38
MARINE...
SMALL CRAFT ADVISORIES ARE IN EFFECT. EAST WINDS WILL INCREASE
TODAY AS A STORM SYSTEM STRENGTHENS AND MOVES ACROSS THE AREA.
RAIN ALONG WITH ISOLATED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED.
A COLD FRONT WILL PUSH OFF THE COAST LATE IN THE DAY AND EARLY
IN THE EVENING WITH STRENGTHENING NORTH WINDS AND BUILDING SEAS
DEVELOPING BEHIND THE BOUNDARY. SOME GALE FORCE WIND GUSTS ARE
POSSIBLE. TODAY...WATER LEVELS MAY EVENTUALLY RISE UP TO 1.5 FEET
ABOVE NORMAL IN RESPONSE TO THE STRENGTHENING EAST WINDS. WATER
FROM WAVE RUN-UP MAY APPROACH THE DUNES AT HIGH TIDE. LEVELS WILL
RETURN TO NEAR NORMAL TONIGHT AND FRIDAY AFTER THE FRONT MOVES ON
THROUGH. LIGHTER WINDS AND SUBSIDING SEAS ARE EXPECTED OVER THE
WEEKEND. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 51 40 48 35 58 / 100 50 40 10 10
HOUSTON (IAH) 56 42 49 35 59 / 100 60 30 10 10
GALVESTON (GLS) 60 44 49 39 55 / 100 60 30 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT CST TONIGHT FOR
THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...
JACKSON...MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CST FRIDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 7 PM CST FRIDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...13