Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/11/15
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
843 PM EST SAT JAN 10 2015
...INCREASING CLOUD COVER WITH WARM TEMPS TONIGHT...
.UPDATE...A STRENGTHENING COASTAL TROUGH AXIS WAS OFFSHORE WITH
HIGH PRESSURE WEDGE AXIS ACROSS OUR INLAND GA ZONES. BROKEN
CLUSTERS OF STRATOCUMULUS WERE MOVING ONSHORE WITH SOME VERY WEAK
RADAR RETURN JUST STARTING TO MANIFEST ABOUT 30 NM OFFSHORE.
DECREASED THE TIMING AND COVERAGE OF EVENING PRECIP BASED ON RADAR
TRENDS AND HRRR WHICH ONLY HAS VERY LIGHT SHOWERS/SPRINKLES
IMPACTING OUR ATLANTIC WATERS THROUGH GENERALLY 06Z...THEN AS
UPPER LEVEL FLOW BACKS SW AFTER MIDNIGHT SHALLOW ISENTROPIC LIFT
ALSO INCREASES. ANTICIPATE AN EXPANSION OF LOW LEVEL CLOUDINESS
TONIGHT AFTER MIDNIGHT AND A GRADUAL WARMING TREND IN TEMPS OR
NEAR STEADY TEMPS AFTER MIDNIGHT DUE TO CLOUD INSULATION. ATLANTIC
SHOWER ACTIVITY IS EXPECTED TO INCREASE AS WELL AFTER MIDNIGHT AS
THE COASTAL TROUGH OFFSHORE EDGES CLOSER TOWARD THE ATLANTIC
COAST. MINS TEMPS WILL RANGE FROM THE UPPER 30S/LOW 40S OVER
INLAND SE GA TO THE MID 50S ALONG THE FL ATLANTIC COAST.
ELEVATED NNE WINDS WERE SUSTAINED 20-25 MPH ALONG THE FL ATLANTIC
COAST THIS EVENING WITH ST AUGUSTINE AND JAX BEACH ACTUALLY
NEARING WIND ADVISORY CRITERIA FOR A COUPLE HOURS HOWEVER
SUSTAINED SPEEDS WERE SLOWLY DECREASING AND ARE EXPECTED TO DO SO
OVERNIGHT AS THE TROUGH AXIS RETROGRADES SLIGHTLY TOWARD THE
ATLANTIC COASTLINE.
&&
.AVIATION...SCATTERED LOW CLOUDS HAVE ADVECTED INLAND FROM THE
ATLANTIC PRODUCING MVFR CIGS AT TIMES THIS EVENING. CLOUDS WILL
INCREASE IN COVERAGE OVERNIGHT WITH MVFR CIGS EXPECTED AT ALL TAF
SITES AFTER 05Z. MODELS SHOW IFR CIGS POSSIBLE AFTER 09Z WITH A
CHANCE OF COASTAL SHOWERS. IFR CIGS SHOULD PERSIST ON SUNDAY AS
INVERTED TROUGH OFFSHORE MAINTAINS A MOIST AND BREEZY NE LOW LEVEL
FLOW.
&&
.MARINE...CURRENT ADVISORY FOR OFFSHORE WATERS AND NEAR SHORE
WATERS NORTH OF ST AUGUSTINE ON TRACK WITH NNE WINDS 17-21 KTS
SUSTAINED AND GUSTS OF 26-27 KTS REPORTED AT BUOY 41008 AND SAUF1
THIS EVENING. SEAS WERE UP TO 6 FT AT THE KINGS BAY BUOY AND 7 FT
AT 41008. NO CHANGES PLANNED TO ONGOING FORECAST WITH WINDS/SEAS
EXPECTED TO GRADUALLY RELAX INTO SUNDAY AS THE COASTAL TROUGH BREAKS
DOWN.
BREAKER HEIGHT PROJECTIONS NOW RANGE FROM 3-4 FT TONIGHT INTO
SUNDAY WITH OCCASIONAL SETS NEAR 5 FT SO AT THIS TIME A HIGH SURF
ADVISORY DOES NOT APPEAR LIKELY.
RIP CURRENTS: MODERATE TO HIGH RISK EXPECTED SUNDAY DUE TO
ELEVATED ONSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 38 56 50 68 / 0 40 50 50
SSI 49 61 56 66 / 20 50 50 50
JAX 47 67 57 73 / 30 50 40 50
SGJ 53 71 61 72 / 50 60 50 50
GNV 47 71 59 76 / 10 30 40 50
OCF 47 77 61 78 / 10 30 30 30
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 5 PM EST MONDAY FOR ALTAMAHA SOUND GA
TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-FERNANDINA
BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-ST
AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR ALTAMAHA SOUND
GA TO FERNANDINA BEACH FL OUT 20 NM-FERNANDINA BEACH TO ST
AUGUSTINE FL OUT 20 NM.
&&
$$
ENYEDI/ZIBURA/WALSH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
543 PM CST SAT JAN 10 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 344 PM CST SAT JAN 10 2015
TEMPERATURES AND CLOUD COVER WERE THE MAIN FORECAST ISSUE FOR
TONIGHT AS SURFACE HIGH PRESSURE MOVES EAST THIS EVENING ALLOWING
FOR A WEAK TROUGH TO PUSH INTO THE STATE OVERNIGHT. FORECAST
SOUNDINGS SUGGEST AN INVERSION DEVELOPING THIS EVENING TRAPPING
LOW LEVEL MOISTURE AND RESULTING IN A STRATUS SHIELD OVER CENTRAL
TO NORTHERN IOWA. PRETTY HIGH RH AT 925MB THIS EVENING AND ALSO
SHOULD BE A LITTLE ADDED MOISTURE WITH THE STRONG WAA TODAY OVER
THE SNOW PACK. INCREASE CLOUD COVER TONIGHT WHICH SHOULD HELP KEEP
OVERNIGHT LOWS UP SLIGHTLY WARMER THAN PREVIOUSLY FORECAST. THE
HOPWRF AND HRRR HAVE CLOUD COVER THROUGH MUCH OF THE NIGHT OVER
THE NORTHERN SECTION OF THE FORECAST AREA.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 344 PM CST SAT JAN 10 2015
A FEW MINOR ISSUES IN THE NEAR TERM...WITH MAINLY A DRY AND QUIET
FORECAST THROUGHOUT THE MID/LONG RANGE. SOUTHERN STREAM UPPER
LEVEL TROUGH WILL BE LIFTING OUT OF THE SOUTHERN HIGH PLAINS
INTO THE OHIO VALLEY SUNDAY INTO EARLY MONDAY. ADDITIONALLY A
NORTHERN STREAM TROUGH WILL BE DROPPING THROUGH THE NORTHERN
PLAINS AND INTO THE GREAT LAKES WITH THAT WAVE SOMEWHAT SHEARING
APART AS IT DROPS SOUTH. WAA AND SOME WEAK THETA-E ADVECTION WILL
CREEP INTO THE FAR SOUTHEASTERN CWA WITH THE SOUTHERN STREAM
TROUGH...WHICH WILL BRING A CHANCE FOR SOME LIGHT SNOW TO THE FAR
SOUTHEASTERN CWA SUNDAY NIGHT. NAM SHOWS DEEPER SATURATION KEEPING
THE PRECIP MAINLY VERY LIGHT SNOW...WHILE THE GFS DOES SHOW SOME
QUESTION AS TO THE DEEPER SATURATION AND ICE INTRODUCTION WITH A
POTENTIAL FOR SOME VERY LIGHT FZDZ. OVERALL THE BULK OF THE PRECIP
IS EXPECTED TO STAY TO THE SOUTH AND SOUTHEAST OF THE CWA...SO
ONLY LIGHT ACCUMULATIONS UNDER AN INCH ARE POSSIBLE AND WENT WITH
HIGH CHANCE POPS. A STRONGER COLD FRONT WILL PUSH THROUGH THE CWA
WITH THE NORTHERN STREAM TROUGH AND COULD BRING SOME FLURRIES
SUNDAY NIGHT TO THE REMAINDER OF THE CWA...AND SOME GUSTY WINDS
INTO MONDAY. COLD ARCTIC HIGH PRESSURE TO BUILD INTO THE CWA FOR
MONDAY NIGHT INTO TUESDAY WITH TEMPS FALLING WELL BELOW NORMAL
AGAIN.
NORTHWESTERLY UPPER LEVEL FLOW REMAINS IN PLACE INTO
THURSDAY...WITH THE FLOW FLATTENING OUT SOME TOWARD THE WEEKEND.
THE MAIN PUSH OF SHORTWAVES SHOULD REMAIN TO THE NORTH OF THE
CWA...SO EXPECT DRY CONDITIONS WITH MAINLY AN INCREASE IN CLOUD
COVER. TEMPERATURES WARM ALOFT AS WELL THROUGH THE END OF THE
PERIOD...SO A WARMING TREND IS ON TAP THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO REBOUND CLOSER TO THE SEASONAL
AVERAGE OR EVEN PUSH ABOVE AVERAGE TOWARD THE END OF THE FORECAST
PERIOD.
&&
.AVIATION...11/00Z
ISSUED AT 534 PM CST SAT JAN 10 2015
FRONTAL BOUNDARY WILL EASE SLOWLY SOUTHEAST ACROSS IOWA TONIGHT
INTO SUNDAY. ANTICIPATE VFR CONDITIONS FOR MUCH OF THE FORECAST
PERIOD ALTHOUGH LOCALIZED AREAS OF MVFR TO IFR MAY DEVELOP NEAR
THE BOUNDARY OVERNIGHT INTO SUNDAY. THIS SHOULD BE THE EXCEPTION
AND NOT THE RULE AS THE BOUNDARY MOVES SOUTH. WINDS WILL BE LIGHT
FROM THE SOUTH SOUTHWEST AHEAD OF THE FRONT WITH LIGHT NORTH TO
NORTHEAST WINDS NORTH OF THE BOUNDARY. MOST CEILINGS WILL BE VFR
CONSISTING OF MID AND HIGH CLOUDS AT OR ABOVE BKN080.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...BEERENDS
AVIATION...COGIL
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1044 PM EST SAT JAN 10 2015
.UPDATE...
ISSUED AT 1043 PM EST SAT JAN 10 2015
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT TRENDS IN OBSERVATIONS.
THIS ALLOWED FOR SLIGHTLY LOWER MIN T IN SOME OF THE EASTERN AND
NORTHEASTERN VALLEYS AND IN THE EKQ AREA. OVERALL...NO SIGNIFICANT
CHANGES WERE NEEDED AT THIS TIME.
UPDATE ISSUED AT 725 PM EST SAT JAN 10 2015
ANOTHER CHILLY NIGHT IS IN STORE...ESPECIALLY IN THE VALLEYS...AS SFC
HIGH PRESSURE BEGINS TO DEPART TO THE EAST TONIGHT. THIS SHOULD SET
THE STAGE FOR A MODERATE RIDGE VALLEY SPLIT ON THE ORDER OF 8 TO 11
DEGREES. THE NORMALLY COLDER EASTERN SPOTS IN NE KY AND NEAR THE WV
AND VA BORDERS MIGHT REACH THE SINGLE DIGITS. ATTM...ONLY SOME
ADJUSTMENTS WERE MADE TO HOURLY TEMP AND DEWPOINT GRIDS BASED ON
RECENT OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 340 PM EST SAT JAN 10 2015
19Z SFC ANALYSIS SHOWS MODIFIED ARCTIC HIGH PRESSURE OVER EASTERN
KENTUCKY. THIS HAS KEPT THE SKIES CLEAR AND WINDS LIGHT TODAY
THROUGHOUT THE AREA...HELPING TO SEND TEMPERATURES INTO THE UPPER
20S AND LOWER 30S FOR MOST OF THE CWA...DESPITE AN AWFULLY CHILLY
START. READINGS AT 3 PM RANGE FROM 25 DEGREES JUST NORTH OF FLEMING
COUNTY TO 34 DEGREES IN BELL AND HARLAN COUNTIES. DEWPOINTS...
MEANWHILE...ARE GENERALLY IN THE LOW SINGLE DIGITS ABOVE ZERO.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE RETREAT OF THE DEEP
TROUGH RESPONSIBLE FOR THIS LATEST COLD BLAST TONIGHT AND THE
APPROACHING OF A WEAKER SOUTHERN STREAM TROUGH INTO SUNDAY NIGHT.
HEIGHTS WILL SLOWLY RISE FROM TONIGHT INTO THE DAY SUNDAY THOUGH
MORE ENERGY WILL START TO STREAM IN FROM THE SOUTHERN STREAM LATER
SUNDAY THROUGH SUNDAY NIGHT. WITH THE GOOD MODEL AGREEMENT HAVE
FOLLOWED THE HRRR AND NAM12 MOST CLOSELY FOR THIS SHORT TERM PORTION
OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE ANOTHER CHILLY NIGHT...BUT MILDER THAN
LAST NIGHT...UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS WILL SET
THE STAGE FOR A DECENT RIDGE TO VALLEY TEMPERATURE DIFFERENCE THROUGH
THE NIGHT. TEMPS WILL REBOUND THROUGH THE DAY SUNDAY EVEN AS CLOUDS
QUICKLY INCREASE AND THICKEN FROM THE WEST. WHILE READINGS ARE
EXPECTED TO RISE ABOVE FREEZING FOR THE ENTIRE CWA BEFORE THE CHANCES
OF LIGHT RAIN MOVE IN...THE DRY AIR IN PLACE MAY RESULT IN A MIXTURE
OF RAIN AND SLEET INITIALLY ALONG AND NORTH OF INTERSTATE 64. IN
ADDITION...THOUGH AIR TEMPERATURE WILL BE A COUPLE OF DEGREES ABOVE
FREEZING...PATCHY FREEZING RAIN WILL BE POSSIBLE DUE TO SUB FREEZING
ROAD TEMPERATURES AND SHADED LOCATIONS. ACCORDINGLY...HAVE ADDED A
TOUCH OF FREEZING RAIN TO THE WX GRIDS FROM LATE SUNDAY AFTERNOON
THROUGH EARLY EVENING. THEREAFTER...RAIN WILL BE THE PCPN TYPE
THROUGH THE REST OF THE NIGHT AS THE FIRST IN A SERIES OF LOW
PRESSURE WAVES RIDES THROUGH THE OHIO VALLEY. TEMPERATURES SHOULD BE
STEADY OR SLOWLY RISE THROUGH THE NIGHT. WILL ISSUE AN SPS TO ADDRESS
THE WINTRY MIX POTENTIAL FOR NORTHERN PARTS OF THE AREA LATE SUNDAY.
ONCE AGAIN USED THE BCCONSSHORT/SUPERBLEND AS A STARTING POINT FOR
THE T...TD...AND WIND GRIDS WITH SOME MODERATE TERRAIN BASED POINT
ADJUSTMENTS FOR LOWS TONIGHT. AS FOR POPS...ENDED UP IN LINE WITH THE
MET MOS THROUGH THE SHORT TERM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 240 PM EST SAT JAN 10 2015
WHILE CONFIDENCE IS HIGH TO START THE UPCOMING WEEK...CONFIDENCE
FADES AS WE HEAD INTO TUESDAY AND BEYOND AS QUESTIONS SWIRL WITH
JUST HOW FAR SOUTH A FRONTAL BOUNDARY STALLS...WHICH IN TURN WILL
DETERMINE JUST HOW ACTIVE AND WHAT TYPE OF PRECIPITATION WE DEAL
WITH THROUGH THURSDAY.
TO START THE PERIOD...A SHORTWAVE TROUGH WILL BE PUSHING ACROSS THE
AREA MONDAY...YIELDING A DAMP DAY WITH PERIODS OF RAIN AND DRIZZLE.
LIFT AND MOISTURE ARE ALL PRESENT TO SUPPORT CATEGORICAL POPS
THROUGH MOST OF THE DAY. BY MONDAY NIGHT...DEEPER MOISTURE WILL EXIT
TO THE SOUTH AND EAST AS A COLD FRONT PUSHES SOUTH. HOWEVER...MODEL
SOUNDINGS REMAIN SUPPORTIVE OF PERSISTENT PERIOD OF DRIZZLE THROUGH
MONDAY NIGHT AND INTO TUESDAY. AT THE SAME TIME...SHALLOW COLD AIR
WILL BE SPREADING SOUTH BEHIND THE COLD FRONT. THIS WILL SET UP THE
STAGE FOR SOME LIGHT FREEZING RAIN/DRIZZLE INTO TUESDAY MORNING.
FORECAST CONFIDENCE ERODES ON TUESDAY...AS GFS KEEPS THE BOUNDARY
FARTHER NORTH...KEEPING THE THREAT OF PRECIPITATION AROUND FOR MUCH
OF SOUTHEAST KENTUCKY THROUGH THE DAY. ON THE OTHER HAND...THE ECMWF
SINKS THE FRONT SOUTHWARD AND KEEPS THE AREA DRY THROUGH TUESDAY AND
BEYOND. SIMPLY CANNOT DISCOUNT THE GFS SOLUTION...SO WILL KEEP SOME
LOW POPS AROUND THROUGH TUESDAY. AS TEMPERATURES ARE NOT EXPECTED TO
CLIMB PAST FREEZING...ANY PRECIPITATION THAT DOES EXIST COULD POSE
PROBLEMS THROUGH THE DAY. HOWEVER...GFS DOES SHOW SOME MID LEVEL
MOISTURE SPREADING BACK OVERHEAD...POSSIBLY SUPPORTING FEEDER/SEEDER
PROCESSES BY LATE MORNING INTO THE AFTERNOON HOURS. AT THE SAME
TIME...STILL A BIT OF A WARM NOSE ON THE GFS SOUNDINGS THROUGH THE
DAY...SO ANY SEEDER FEEDER PROCESSES COULD JUST INCREASE THE
INTENSITY OF ANY FREEZING RAIN. HOWEVER...ANY SLIGHT CHANGES IN THE
LOWER TEMPERATURE PROFILE ON TUESDAY WOULD SIGNIFICANT ALTER
PRECIPITATION TYPE. THUS...PLANNING TO GO FAIRLY LIBERAL ON THE
PRECIPITATION TYPES THIS FAR OUT AND GO WITH A MIXTURE OF
SLEET/FREEZING RAIN/AND POSSIBLY SOME SNOW ENTERING THE PICTURE ON
TUESDAY.
BY TUESDAY NIGHT INTO THURSDAY...THE QUESTIONS REMAIN ON HOW FAR
NORTH PRECIPITATION CHANCES WILL LAST. THE ECMWF REMAINS LESS
OPTIMISTIC ON ANY PRECIPITATION CHANCES...WHILE THE GFS KEEPS SOME
CHANCES IN SOUTHEAST KENTUCKY THROUGH THURSDAY. GIVEN THE MODELS
DISAGREEMENT HAVE OPTED FOR SOME LOW POPS THROUGH THURSDAY ACROSS
SOUTHEAST KENTUCKY. IF PRECIPITATION OCCURS...THE THREAT FOR
FREEZING DRIZZLE...SNOW...AND RAIN WILL CONTINUE. THUS...THERE IS A
CHANCE FOR A AN EXTENDED PERIOD OF FROZEN PRECIPITATION IN SOUTHEAST
KENTUCKY. ALL MODELS ARE TRENDING DRIER BY LATE THURSDAY INTO NEXT
WEEKEND...SO WILL DRY OUT THE FORECAST FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 725 PM EST SAT JAN 10 2015
HIGH PRESSURE...RETREATING TONIGHT INTO SUNDAY...WILL PROVIDE VFR
CONDITIONS ACROSS THE AREA THROUGH THE BULK OF THE PERIOD. JUST
TOWARD THE LAST 6 HOURS...18Z TO 0Z...WILL SOME MID AND LOW CLOUDS
MOVE IN FROM THE WEST AND SOUTHWEST. BY 18Z TO 21Z CIGS NEAR MVFR
WILL BE ON THE DOORSTEP OF WESTERN PARTS OF THE FORECAST
AREA...SPREADING ACROSS THE REMAINDER OF THE AREA AROUND THE END OF
THE PERIOD. UNDER THE HIGH/S INFLUENCE...WINDS WILL BE AT 5 KT OR
LESS FROM THE SOUTH TONIGHT. THE WINDS WILL START TO PICK UP FROM THE
SOUTH SOUTHWEST AFTER 14Z WITH SPEEDS OF 5 TO 10 KT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
729 PM EST SAT JAN 10 2015
.UPDATE...
ISSUED AT 725 PM EST SAT JAN 10 2015
ANOTHER CHILLY NIGHT IS IN STORE...ESPECIALLY IN THE VALLEYS...AS SFC
HIGH PRESSURE BEGINS TO DEPART TO THE EAST TONIGHT. THIS SHOULD SET
THE STAGE FOR A MODERATE RIDGE VALLEY SPLIT ON THE ORDER OF 8 TO 11
DEGREES. THE NORMALLY COLDER EASTERN SPOTS IN NE KY AND NEAR THE WV
AND VA BORDERS MIGHT REACH THE SINGLE DIGITS. ATTM...ONLY SOME
ADJUSTMENTS WERE MADE TO HOURLY TEMP AND DEWPOINT GRIDS BASED ON
RECENT OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 340 PM EST SAT JAN 10 2015
19Z SFC ANALYSIS SHOWS MODIFIED ARCTIC HIGH PRESSURE OVER EASTERN
KENTUCKY. THIS HAS KEPT THE SKIES CLEAR AND WINDS LIGHT TODAY
THROUGHOUT THE AREA...HELPING TO SEND TEMPERATURES INTO THE UPPER
20S AND LOWER 30S FOR MOST OF THE CWA...DESPITE AN AWFULLY CHILLY
START. READINGS AT 3 PM RANGE FROM 25 DEGREES JUST NORTH OF FLEMING
COUNTY TO 34 DEGREES IN BELL AND HARLAN COUNTIES. DEWPOINTS...
MEANWHILE...ARE GENERALLY IN THE LOW SINGLE DIGITS ABOVE ZERO.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE RETREAT OF THE DEEP
TROUGH RESPONSIBLE FOR THIS LATEST COLD BLAST TONIGHT AND THE
APPROACHING OF A WEAKER SOUTHERN STREAM TROUGH INTO SUNDAY NIGHT.
HEIGHTS WILL SLOWLY RISE FROM TONIGHT INTO THE DAY SUNDAY THOUGH
MORE ENERGY WILL START TO STREAM IN FROM THE SOUTHERN STREAM LATER
SUNDAY THROUGH SUNDAY NIGHT. WITH THE GOOD MODEL AGREEMENT HAVE
FOLLOWED THE HRRR AND NAM12 MOST CLOSELY FOR THIS SHORT TERM PORTION
OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE ANOTHER CHILLY NIGHT...BUT MILDER THAN
LAST NIGHT...UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS WILL SET
THE STAGE FOR A DECENT RIDGE TO VALLEY TEMPERATURE DIFFERENCE THROUGH
THE NIGHT. TEMPS WILL REBOUND THROUGH THE DAY SUNDAY EVEN AS CLOUDS
QUICKLY INCREASE AND THICKEN FROM THE WEST. WHILE READINGS ARE
EXPECTED TO RISE ABOVE FREEZING FOR THE ENTIRE CWA BEFORE THE CHANCES
OF LIGHT RAIN MOVE IN...THE DRY AIR IN PLACE MAY RESULT IN A MIXTURE
OF RAIN AND SLEET INITIALLY ALONG AND NORTH OF INTERSTATE 64. IN
ADDITION...THOUGH AIR TEMPERATURE WILL BE A COUPLE OF DEGREES ABOVE
FREEZING...PATCHY FREEZING RAIN WILL BE POSSIBLE DUE TO SUB FREEZING
ROAD TEMPERATURES AND SHADED LOCATIONS. ACCORDINGLY...HAVE ADDED A
TOUCH OF FREEZING RAIN TO THE WX GRIDS FROM LATE SUNDAY AFTERNOON
THROUGH EARLY EVENING. THEREAFTER...RAIN WILL BE THE PCPN TYPE
THROUGH THE REST OF THE NIGHT AS THE FIRST IN A SERIES OF LOW
PRESSURE WAVES RIDES THROUGH THE OHIO VALLEY. TEMPERATURES SHOULD BE
STEADY OR SLOWLY RISE THROUGH THE NIGHT. WILL ISSUE AN SPS TO ADDRESS
THE WINTRY MIX POTENTIAL FOR NORTHERN PARTS OF THE AREA LATE SUNDAY.
ONCE AGAIN USED THE BCCONSSHORT/SUPERBLEND AS A STARTING POINT FOR
THE T...TD...AND WIND GRIDS WITH SOME MODERATE TERRAIN BASED POINT
ADJUSTMENTS FOR LOWS TONIGHT. AS FOR POPS...ENDED UP IN LINE WITH THE
MET MOS THROUGH THE SHORT TERM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 240 PM EST SAT JAN 10 2015
WHILE CONFIDENCE IS HIGH TO START THE UPCOMING WEEK...CONFIDENCE
FADES AS WE HEAD INTO TUESDAY AND BEYOND AS QUESTIONS SWIRL WITH
JUST HOW FAR SOUTH A FRONTAL BOUNDARY STALLS...WHICH IN TURN WILL
DETERMINE JUST HOW ACTIVE AND WHAT TYPE OF PRECIPITATION WE DEAL
WITH THROUGH THURSDAY.
TO START THE PERIOD...A SHORTWAVE TROUGH WILL BE PUSHING ACROSS THE
AREA MONDAY...YIELDING A DAMP DAY WITH PERIODS OF RAIN AND DRIZZLE.
LIFT AND MOISTURE ARE ALL PRESENT TO SUPPORT CATEGORICAL POPS
THROUGH MOST OF THE DAY. BY MONDAY NIGHT...DEEPER MOISTURE WILL EXIT
TO THE SOUTH AND EAST AS A COLD FRONT PUSHES SOUTH. HOWEVER...MODEL
SOUNDINGS REMAIN SUPPORTIVE OF PERSISTENT PERIOD OF DRIZZLE THROUGH
MONDAY NIGHT AND INTO TUESDAY. AT THE SAME TIME...SHALLOW COLD AIR
WILL BE SPREADING SOUTH BEHIND THE COLD FRONT. THIS WILL SET UP THE
STAGE FOR SOME LIGHT FREEZING RAIN/DRIZZLE INTO TUESDAY MORNING.
FORECAST CONFIDENCE ERODES ON TUESDAY...AS GFS KEEPS THE BOUNDARY
FARTHER NORTH...KEEPING THE THREAT OF PRECIPITATION AROUND FOR MUCH
OF SOUTHEAST KENTUCKY THROUGH THE DAY. ON THE OTHER HAND...THE ECMWF
SINKS THE FRONT SOUTHWARD AND KEEPS THE AREA DRY THROUGH TUESDAY AND
BEYOND. SIMPLY CANNOT DISCOUNT THE GFS SOLUTION...SO WILL KEEP SOME
LOW POPS AROUND THROUGH TUESDAY. AS TEMPERATURES ARE NOT EXPECTED TO
CLIMB PAST FREEZING...ANY PRECIPITATION THAT DOES EXIST COULD POSE
PROBLEMS THROUGH THE DAY. HOWEVER...GFS DOES SHOW SOME MID LEVEL
MOISTURE SPREADING BACK OVERHEAD...POSSIBLY SUPPORTING FEEDER/SEEDER
PROCESSES BY LATE MORNING INTO THE AFTERNOON HOURS. AT THE SAME
TIME...STILL A BIT OF A WARM NOSE ON THE GFS SOUNDINGS THROUGH THE
DAY...SO ANY SEEDER FEEDER PROCESSES COULD JUST INCREASE THE
INTENSITY OF ANY FREEZING RAIN. HOWEVER...ANY SLIGHT CHANGES IN THE
LOWER TEMPERATURE PROFILE ON TUESDAY WOULD SIGNIFICANT ALTER
PRECIPITATION TYPE. THUS...PLANNING TO GO FAIRLY LIBERAL ON THE
PRECIPITATION TYPES THIS FAR OUT AND GO WITH A MIXTURE OF
SLEET/FREEZING RAIN/AND POSSIBLY SOME SNOW ENTERING THE PICTURE ON
TUESDAY.
BY TUESDAY NIGHT INTO THURSDAY...THE QUESTIONS REMAIN ON HOW FAR
NORTH PRECIPITATION CHANCES WILL LAST. THE ECMWF REMAINS LESS
OPTIMISTIC ON ANY PRECIPITATION CHANCES...WHILE THE GFS KEEPS SOME
CHANCES IN SOUTHEAST KENTUCKY THROUGH THURSDAY. GIVEN THE MODELS
DISAGREEMENT HAVE OPTED FOR SOME LOW POPS THROUGH THURSDAY ACROSS
SOUTHEAST KENTUCKY. IF PRECIPITATION OCCURS...THE THREAT FOR
FREEZING DRIZZLE...SNOW...AND RAIN WILL CONTINUE. THUS...THERE IS A
CHANCE FOR A AN EXTENDED PERIOD OF FROZEN PRECIPITATION IN SOUTHEAST
KENTUCKY. ALL MODELS ARE TRENDING DRIER BY LATE THURSDAY INTO NEXT
WEEKEND...SO WILL DRY OUT THE FORECAST FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 725 PM EST SAT JAN 10 2015
HIGH PRESSURE...RETREATING TONIGHT INTO SUNDAY...WILL PROVIDE VFR
CONDITIONS ACROSS THE AREA THROUGH THE BULK OF THE PERIOD. JUST
TOWARD THE LAST 6 HOURS...18Z TO 0Z...WILL SOME MID AND LOW CLOUDS
MOVE IN FROM THE WEST AND SOUTHWEST. BY 18Z TO 21Z CIGS NEAR MVFR
WILL BE ON THE DOORSTEP OF WESTERN PARTS OF THE FORECAST
AREA...SPREADING ACROSS THE REMAINDER OF THE AREA AROUND THE END OF
THE PERIOD. UNDER THE HIGH/S INFLUENCE...WINDS WILL BE AT 5 KT OR
LESS FROM THE SOUTH TONIGHT. THE WINDS WILL START TO PICK UP FROM THE
SOUTH SOUTHWEST AFTER 14Z WITH SPEEDS OF 5 TO 10 KT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
235 PM EST FRI JAN 9 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 235 PM EST FRI JAN 9 2015
18Z SFC ANALYSIS SHOWS THE NEXT ARCTIC HIGH PRESSURE BUILDING INTO
EASTERN KENTUCKY FROM THE PLAINS. THE COLD FRONT ASSOCIATED WITH THIS
HAS MOVED WELL INTO EASTERN KENTUCKY...LEAVING ITS BAND OF
DISSIPATING CLOUDS AND SNOW BEHIND. JUST A FEW LINGERING FLURRIES
ARE FADING OUT OVER NORTHEASTERN PARTS OF THE FORECAST AREA. THE
SUNSHINE...AND POSITION JUST AHEAD OF THE ARCTIC BOUNDARY...HAS BEEN
ENOUGH FOR MANY LOCATIONS TO MAKE IT TO FREEZING OR A TICK ABOVE
THROUGH FAR SOUTHEAST KENTUCKY...BUT TEMPERATURES ARE NOW ON THE
WAY BACK DOWN. READINGS AT 2 PM RANGE FROM THE MID 20S IN THE
NORTHWEST TO THE LOWER 30S IN THE SOUTHEAST WHILE DEWPOINTS ARE IN
THE LOW SINGLE DIGITS NORTH AND NEAR 10 DEGREES IN THE SOUTH. WINDS
THROUGH THE AREA HAVE SWITCHED TO MORE WESTERLY AT 10 TO 15 MPH WITH
A FEW GUSTS TO 25 MPH STILL POSSIBLE...WHILE A BIT MORE BEHIND THE
FRONT THE DIRECTION IS MORE FROM THE NORTHWEST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL DEPICT THE DEEP TROUGH RESIDENT THROUGH THE GREAT LAKES AND OHIO
VALLEY INTO SATURDAY MORNING. THIS TROUGH THEN SHIFTS OFF TO THE EAST
AND RELAXES ITS GRIP ON THE REGION AS HEIGHTS REBOUND QUICKLY BY
SATURDAY EVENING. ATTENTION WILL THEN TURN TO A DEVELOPING SOUTHERN
STREAM TROUGH MOVING INTO THE SOUTHERN PLAINS BY SUNDAY MORNING AS
THE FLOW TURNS SOUTHWESTERLY OVER KENTUCKY. WITH THE GENERAL MODEL
AGREEMENT HAVE FAVORED THE HIGHER RESOLUTION NAM12 AND HRRR FOR THE
SHORT TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE BRISK CONDITIONS INTO THE EVENING AS
NORTHWEST WINDS BRING IN COLDER TEMPERATURES. THIS LATEST ARCTIC
SURGE WILL NOT BE QUITE AS COLD AS THE LAST ONE WITH TEMPERATURES
BOTTOMING OUT IN THE MID AND UPPER SINGLE DIGITS BY DAWN SATURDAY.
WITH THE WINDS SETTLING AS THE COLDEST AIR MOVES IN WE WILL BE SPARED
THE WORST OF THE WIND CHILLS...THOUGH...THEY WILL LIKELY DROP TO
NEAR ZERO IN A FEW PLACES TONIGHT. THE CHILLY HIGH PRESSURE WILL
MODERATE THROUGH THE DAY SATURDAY WITH AMPLE SUNSHINE RETURNING
TEMPERATURES INTO THE MIDDLE AND UPPER 20S BY AFTERNOON FOR MOST
PLACES ACROSS EASTERN KENTUCKY. SOME HIGH CLOUDS MAY BUILD INTO THE
REGION LATER SATURDAY NIGHT AS THE RETREATING HIGH SETS THE STAGE FOR
A SMALL TO MODERATE RIDGE/VALLEY TEMPERATURE SPLIT.
AGAIN USED THE BCCONSSHORT/SUPERBLEND AS A STARTING POINT FOR THE
T...TD...AND WIND GRIDS WITH SOME MINOR TERRAIN BASED POINT
ADJUSTMENTS FOR HIGHS AND LOWS. AS FOR POPS...ASIDE FROM SOME
LINGERING SINGLE DIGIT VALUES EARLY THIS EVENING IN THE FAR
EAST...HAVE BASICALLY ZEROED OUT POPS THROUGH SUNDAY MORNING...ALSO
IN LINE WITH MOS GUIDANCE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 230 PM EST FRI JAN 9 2015
SUNDAY SHOULD REMAIN DRY ACROSS THE AREA...BUT A WARM FRONT
ADVANCING NORTHWARD ACROSS THE AREA WILL BRING INCREASING CLOUDS.
DOWNSLOPING SOUTHEAST FLOW OFF THE HIGH TERRAIN WILL ATTEMPT TO KEEP
PRECIPITATION AT BAY THROUGH MOST OF THE DAY...BUT MODELS ARE
BEGINNING TO TREND SLIGHTLY FASTER WITH PRECIPITATION MAKING INTO
SOUTH CENTRAL KENTUCKY BY EARLY EVENING. FORTUNATELY...SURFACE
TEMPERATURES WILL BE MILDER WITH HIGHS INTO THE 40S ON SUNDAY WITH
WITH CLOUDS MOVING ON IN...THEY ARE NOT EXPECTED TO FALL OFF MUCH
INTO THE NIGHT. THUS...AS IT STANDS NOW...WE SHOULD SEE PRIMARILY
RAIN ACROSS THE AREA WITH THE SUBFREEZING TEMPERATURES (AND FREEZING
RAIN THREAT) STAYING JUST TO OUR NORTH. GIVEN THE ABUNDANCE OF DRY
AIR IN PLACE AT THE BEGINNING OF THE PRECIPITATION...WE MAY SEE A
BIT OF SLEET MIX IN INITIALLY BEFORE SEEING JUST RAIN. THE SLEET
THREAT WILL BE PRIMARILY BEFORE MIDNIGHT SUNDAY NIGHT. A SHORTWAVE
TROUGH WILL THEN PUSH ACROSS THE AREA ON MONDAY WITH A COLD FRONT
ADVANCING SOUTHWARD. THIS WILL KEEP PRECIPITATION ONGOING ON MONDAY
WITH THE POSSIBILITY OF RAIN MIXING WITH AND PERHAPS CHANGING TO
SNOW LATE MONDAY. HOWEVER...AS MENTIONED PREVIOUSLY...DEEPER
MOISTURE IS DEPARTING THROUGH THE EVENING HOURS MONDAY...AND WE MAY
LOSE THE ICE IN THE CLOUDS...WHICH WOULD SUPPORT MORE DRIZZLE VERSES
SNOW. REGARDLESS...ANY SNOW SHOULD HAVE VERY LOW IMPACT ON THE AREA
AS SURFACE TEMPERATURES REMAIN ABOVE FREEZING...LIMITING ANY SNOW
ACCUMULATION.
BY MONDAY NIGHT...MOISTURE DEPARTS THE AREA WITH ONLY A SLIGHT
CHANCE OF LINGERING RAIN OR SNOW ACROSS SOUTHEAST KENTUCKY INTO THE
OVERNIGHT HOURS. AFTER A DRY PERIOD ON TUESDAY...A STALLED FRONTAL
BOUNDARY JUST TO OUR SOUTH WILL LIFT BACK NORTH BY TUESDAY NIGHT
INTO WEDNESDAY WITH THE THREAT OF SNOW RETURNING TO THE AREA.
MOISTURE IS RATHER LIMITED...BUT A LIGHT DUSTING OF SNOW MAY BE
POSSIBLE. BETTER CHANCES OF SNOW WILL ARRIVE LATE WEDNESDAY NIGHT
INTO THURSDAY AS A BETTER SHORTWAVE TROUGH PUSHES ACROSS THE
SOUTHERN US. MODELS HAVE TRENDED FARTHER SOUTH WITH THIS SYSTEM
KEEPING EASTERN KENTUCKY ON THE VERY NORTHERN FRINGES OF THIS
SYSTEM. STILL LOTS OF DETAILS TO BE WORKED OUT WITH THIS
SYSTEM...BUT IT LOOKS LIKE ANY PRECIPITATION WOULD BE PRIMARILY
SNOW...ALTHOUGH NOT A LOT OF COLD AIR IN PLACE WITH THIS
SYSTEM...AND PRECIPITATION TYPE MIGHT BE DETERMINED BY PRECIPITATION
INTENSITY...WITH BETTER RATES YIELDING SNOW...AND LIGHTER RATES
BEING MORE RAIN OR DRIZZLE. WE WILL HAVE TO SEE IF THE SOUTHERN
TREND CONTINUES AS THIS COULD SHIFT PRECIPITATION SOUTH OF THE AREA
IF IT CONTINUES. THE WEATHER WILL FINALLY QUIET DOWN BY LATE
THURSDAY WITH A QUIETER...BUT STILL CHILLY END TO THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 115 PM EST FRI JAN 9 2015
WITH THE CLOUDS THINNING OUT AND BREAKING UP AS THE ARCTIC BOUNDARY
MOVES IN...DO NOT EXPECT MUCH IN THE WAY OF MVFR CIGS UNTIL MAYBE
LATE TONIGHT WHEN THE UPSLOPE FLOW TAKES HOLD...FOR A TIME.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD AT ALL
SITES. WINDS WILL TURN MORE NORTHWESTERLY THROUGH THE REST OF THE
AFTERNOON AND INTO THE EVENING...SETTLING FROM BREEZY 10 TO 20 KTS
WITH HIGHER GUSTS TO AROUND 5 KTS BY 06Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
150 AM EST FRI JAN 9 2015
.UPDATE...
ISSUED AT 150 AM EST FRI JAN 9 2015
STRONG LOW LEVEL WARM AIR ADVECTION CONTINUES OUT AHEAD OF THE
APPROACHING COLD FRONT...WITH MOST VALLEY LOCATIONS REPORTING IN THE
30S. SUSTAINED SOUTHWEST WINDS OF 10 TO 20 MPH...WITH GUSTS OF 30 TO
35 MPH HAVE BEEN COMMON OVERNIGHT. EXCEPTIONALLY DRY AIR WILL KEEP
THE SNOW AT BAY FOR MOST OF THE OVERNIGHT...UNTIL THE FRONT DRAWS
CLOSER AND ALLOWS FOR SOME MOISTENING OF THE LOW LEVELS. HAVE SLOWED
DOWN THE POPS GIVEN THE CURRENT TRENDS AND BEEFED UP THE WINDS. THE
STRONGER WIND GUSTS SHOULD SUBSIDE CLOSER TO DAWN...AS THE LOW LEVEL
JET RELAXES ACROSS THE AREA. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 1100 PM EST THU JAN 8 2015
TONIGHT AHEAD OF APPROACHING DISTURBANCE WE HAVE SEEN WINDS BEGIN TO
INCREASE AS WELL AS STEADY RISE IN TEMPERATURES TONIGHT. EXPECTING TO
CONTINUE TO SEE INCREASING MID AND HIGH CLOUDS OVERNIGHT. WSR-88D
RADAR CONTINUES TO SHOW SOME WEAK RETURNS ACROSS PORTION OF CENTRAL
AND FAR NORTHERN KY TONIGHT. MUCH OF THIS WOULD AT MOST PRODUCE
FLURRIES GIVEN THE DRY AIR IN PLACE WOULD EXPECT MUCH OF THIS IS NOT
REACHING THE GROUND...HOWEVER EVEN WITH DRY AIR IN PLACE THERE WERE
SOME OBS IN SOUTHERN OH THAT DID REPORT LIGHT SNOW. GIVEN THIS OPTED
TO KEEP BLUEGRASS DRY AT THIS POINT. THE QUESTION IN THE FORECAST AT
THIS POINT WOULD BE THE UPSTREAM FRONT AND HOW MUCH OF THIS MOISTURE
MAKES IT ACROSS THE REGION EARLY TOMORROW. MODELS INCLUDING MESOSCALE
MODELS CONTINUE TO INDICATE LITTLE TO NO PRECIP WITH THIS FRONT.
RIGHT NOW THIS BAND OF PRECIP IS AFFECTING PORTIONS OF CENTRAL AND
NORTHERN IL AND WILL HAVE TO BE MONITORED OVERNIGHT. UPDATED
TEMPS/DEWPOINTS/WINDS WITH LATEST OBS AND TRENDS OTHERWISE NO MAJOR
CHANGES NEEDED AT THIS TIME.
UPDATE ISSUED AT 742 PM EST THU JAN 8 2015
HIGH PRESSURE IS CENTERED EAST OF THE REGION THIS EVENING. THIS IS
BRING SOUTH TO SOUTHWEST FLOW ACROSS EASTERN KY THIS EVENING...WITH
HIGH TO MID LEVEL CLOUDS CONTINUING TO STREAM IN FROM THE WEST. WSR-
88D RADAR DOES INDICATE SOME VERY LIGHT RETURNS APPROACHING EASTERN
KY...HOWEVER NONE OF THESE RETURNS ARE ACTUALLY HITTING THE GROUND AT
THIS POINT. UPDATED WITH LATEST OBS AND TREND WITH FORECAST ON TRACK
AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 355 PM EST THU JAN 8 2015
19Z SFC ANALYSIS SHOWS THAT THE CORE OF THE ARCTIC HIGH HAS SHIFTED
SOUTHEAST OF THE AREA THIS AFTERNOON. FAIRLY DEEP LOW PRESSURE EXISTS
OVER THE UPPER MIDWEST WITH A COLD FRONT STRETCHING OFF TO THE
SOUTHWEST. A TIGHTENING PRESSURE GRADIENT IS FOUND BETWEEN THE LOW
TO THE NORTH AND THE HIGH TO THE SOUTH. THIS IS TURNING THE WINDS TO
THE SOUTHWEST AND INCREASING THEIR SPEEDS...NORTHERN PARTS OF THE
AREA FIRST AND THE SOUTH LATER. THE EARLIER SUNSHINE...THESE
STRENGTHENING SOUTHERN WINDS...AND THE DEPARTING HIGH HAS ALLOWED
TEMPERATURES TO REBOUND INTO THE UPPER TEENS AND LOW 20S IN MOST
PLACES THROUGHOUT THE AREA WITH THE WARMER VALUES GENERALLY FOUND IN
THE CUMBERLAND VALLEY. DEWPOINTS...MEANWHILE...ARE STILL RATHER
LOW...RIGHT AROUND ZERO.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE MAIN PATTERN THROUGH
THE REGION DURING THE SHORT TERM PORTION OF THE FORECAST. THEY ALL
DEPICT A DEEP SECONDARY TROUGH BUILDING INTO THE OHIO VALLEY ON
FRIDAY BEFORE RETREATING TO THE EAST DURING INTO THE DAY SATURDAY AND
ALLOWING THE HEIGHTS TO REBOUND. GIVEN THE AGREEMENT ALOFT WILL
FOLLOW A GENERAL BLEND BUT FAVOR THE HIGHER RESOLUTION NAM12 AND HRRR
FOR WX DETAILS.
SENSIBLE WEATHER WILL FEATURE A REINFORCING ARCTIC BOUNDARY MOVING
INTO THE STATE LATER TONIGHT AND THROUGH BY EARLY FRIDAY MORNING.
AHEAD OF THIS...CONDITIONS WILL BE MILDER TONIGHT DUE TO THE
ASSOCIATED CLOUDS AND SOUTH TO SOUTHWEST WINDS STAYING UP THROUGH THE
NIGHT. THE MODELS HAVE BEEN TRENDING DRIER WITH THIS WITH THE GFS
PALTRY AND THE NAM12 A BIT MORE ROBUST. THE HRRR MEANWHILE KEEPS
THINGS DRY WITH THIS BOUNDARY THROUGH 08Z. THE SREF POPS HAVE ALSO
DROPPED WITH THIS FRONT OVER THE PAST COUPLE OF RUNS. DO EXPECT SOME
FLURRIES AND A SNOW SHOWER OR TWO AROUND AS THIS FRONT GOES THROUGH
BUT IT SHOULD BE NOWHERE AS EXTENSIVE OR OCCASIONALLY INTENSE AS IT
WAS WEDNESDAY GIVEN THE LIMITED MOISTURE. ACCORDINGLY...WILL KEEP
MENTION OF THE SNOW THREAT MAINLY IN THE HWO WHILE ALLOWING FOR
ISOLATED TO SCATTERED SNOW SHOWERS FROM LATE TONIGHT INTO FRIDAY
MORNING. POST FRONTAL...EXPECT BRISK WEST WINDS TO BRING IN COLDER
TEMPERATURES WITH LOWS FRIDAY NIGHT DOWN INTO THE SINGLE DIGITS MOST
PLACES...BUT NOT QUITE AS COLD AS THEY WERE THIS MORNING.
USED THE BCCONSSHORT AND SUPERBLEND AS A STARTING POINT FOR THE
T...TD...AND WIND GRIDS WITH SOME MINOR TERRAIN BASED POINT
ADJUSTMENTS FOR HIGHS AND LOWS. GIVEN THE NON DIURNAL TEMPERATURE
TRENDS OVER THE NEXT 36 HOURS DID NOT DEVIATE MUCH FROM THE RAW
CONSENSUS MODEL DATA. AS FOR POPS...ENDED UP HIGHER THAN ALL MOS FOR
LATE TONIGHT AND FRIDAY AND THEN AGREED WITH THEIR LOW SINGLE DIGITS
FOR FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 338 PM EST THU JAN 8 2015
ACTIVE PATTERN WILL CONTINUE THROUGH THE EXTENDED WITH TWO MORE
SYSTEMS POISED TO AFFECT THE AREA NEXT WEEK. HOWEVER...THE MAJORITY
OF THE WEEKEND CONTINUES TO LOOK DRY WITH VERY DRY AIR HOLDING OVER
EASTERN KENTUCKY THANKS TO A LARGE AREA OF HIGH PRESSURE. IN
FACT...WE MAY SEE SOME FAIRLY LOW RELATIVE HUMIDITY VALUES SATURDAY
AND SUNDAY AFTERNOONS. BY LATE SUNDAY AND SUNDAY NIGHT...HIGH
PRESSURE WILL EXIT TO THE EAST WITH MOISTURE ON THE INCREASE. A
MODEST WARM NOSE IS EXPECTED TO PUSH BACK TO THE NORTH SUNDAY
NIGHT...LIKELY KEEPING PRECIPITATION IN THE FORM OF RAIN. GIVEN THE
DRY AIR IN PLACE INITIALLY...CLOUD SEE A BRIEF PERIOD OF SLEET ON
THE ONSET OF PRECIPITATION. THE BIG QUESTION FOR SUNDAY NIGHT INTO
MONDAY MORNING IS HOW SURFACE TEMPERATURES RESPOND. MODELS ARE
SUGGESTING SOME AREAS MAY NOT CLIMB BACK TO AROUND FREEZING UNTIL
AFTER DAYBREAK...WHICH WOULD SUPPORT SOME FREEZING RAIN. BEST
CHANCES APPEAR TO RESIDE ALONG OR NORTH OF I-64...BUT SOME OF THE
MORE SHELTERED VALLEYS COULD BE AT PLAY AS WELL. CERTAINLY SOMETHING
TO WATCH AS WE GET CLOSER TO THIS EVENT. ON MONDAY...WE SHOULD SEE
TEMPERATURES WARM ABOVE FREEZING AS PRECIPITATION CONTINUES TO
SPREAD ACROSS THE AREA. THIS WILL KEEP EVERYTHING RAIN FOR MUCH OF
MONDAY. AS THIS SYSTEM EXITS MONDAY NIGHT...SLIGHTLY COLDER AIR WILL
BE DRAWN SOUTHWARD...BUT MOISTURE WILL ALSO BE EXITING. THIS MAY
YIELD EITHER A BRIEF PERIOD OF SNOW OR DRIZZLE AS THIS SYSTEM PULLS
OUT. NOT LOOKING FOR MUCH OF AN ISSUE HERE...BUT WE SHOULD SEE A FEW
SLICK ROADS DEVELOPING OVERNIGHT.
BY TUESDAY AND TUESDAY NIGHT...MODELS ARE TRENDING TOWARDS MORE OF A
LULL AS A FRONTAL BOUNDARY SETTLES JUST SOUTH OF THE AREA. WE COULD
SEE SOME FLURRIES OR DRIZZLE PERSIST THROUGH THIS PERIOD IN THE
SOUTHEAST...BUT ANY PRECIPITATION WILL REMAIN VERY LIGHT. OUR NEXT
SYSTEM TO CONTEND WITH WILL HEAD TOWARDS THE AREA LATE WEDNESDAY
THROUGH WEDNESDAY NIGHT. GFS KEEPS THIS SYSTEM SUPPRESSED TO OUR
SOUTH...WHILE THE ECMWF IS WEAKER...BUT FARTHER NORTH. BOTH MODELS
SUPPORT THE IDEA OF MORE SNOW AS THE MAIN PRECIPITATION TYPE...JUST
A QUESTION OF WHERE AND HOW MUCH. CLEARLY THIS SYSTEM REMAINS AROUND
THE DAY 7 PERIOD AND GIVEN THE UNCERTAINTY...NOT GOING TO SPEND TOO
MUCH TIME ON THE DETAILS AS THEY ARE LIKELY TO CHANGE ANYWAYS.
HOWEVER...MAIN TAKEAWAY IS THERE WILL BE A POTENTIAL FOR WINTRY
PRECIPITATION BY WEDNESDAY NIGHT. STILL NOT A LOT OF COLD AIR TO
WORK WITH AROUND THIS SYSTEM AS THE COLD AIR HAS ALL RETREATED WELL
TO OUR NORTH BY THIS TIME. HOWEVER...NOT MUCH OF A WARM NOSE
EITHER...SO WE COULD BE LOOKING AT A WET SNOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 150 AM EST FRI JAN 9 2015
AN APPROACHING COLD FRONT WILL ALLOW FOR DROPPING CEILINGS AND
PERHAPS A FEW SNOW SHOWERS...ESPECIALLY NORTH OF THE MOUNTAIN
PARKWAY TOWARDS DAWN. HAVE HELD ONTO VFR CONDITIONS THROUGH FRONTAL
PASSAGE WITH THE EXCEPTION OF KSYM...WHERE SOME BRIEF MVFR CEILINGS
STILL LOOK POSSIBLE. THE BIGGER IMPACT WITH THIS SYSTEM WILL BE THE
STRONG WIND GUSTS CONTINUING THROUGH THE MID TO LATE MORNING.
SUSTAINED SOUTHWEST WINDS OF 10 TO 20 KTS...WITH GUSTS OF 25 TO 30
KTS WILL BE COMMON. WINDS WILL VEER TO THE WEST WITH THE FRONTAL
PASSAGE BETWEEN 14 AND 17Z FROM NORTHWEST TO SOUTHEAST. ANY SNOW
FLURRIES OR LIGHT SNOW SHOWERS WILL BE ENDING BY 21Z WITH CLOUDS
SCATTERING OUT. WINDS WILL DIMINISH BY DUSK AS HIGH PRESSURE
GRADUALLY BUILDS IN ACROSS THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1156 AM EST FRI JAN 9 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY. ARCTIC HIGH
PRESSURE WILL RETURN FOR TONIGHT AND SATURDAY BEFORE MOVING EAST
SUNDAY. LOW PRESSURE MAY IMPACT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
WE HV DROPPED THE WIND AVSRY FOR HIGHER ELEVS. ALSO UPDATED THE
TEMPS WHICH WERE ALREADY APRCHG THE FCSTD HIGHS IN MANY SPOTS. THE
TEMPS CLIMB WL LKLY END AFTR THE FNT PASSES THRU THE AREA.
WE ARE KEEPING EYES ON THE LGT BAND OF SNSH IN ASSO W/ THE CD FNT
APRCHG GARRETT CO. HRRR DEPICTS IT WEAKENING AS IT MOVES E.
PRVS DSCN...
THE SHORTWAVE TROUGH WILL MOVE OFF THE EAST COAST THIS AFTERNOON
AND CLOUDS WILL CLEAR AS SUBSIDENCE MOVES INTO THE REGION. A SFC
TROUGH OR COLD FRONT WILL MOVE ACROSS THE REGION SHORTLY AFTER THE
SHORTWAVE TROUGH MOVES OFF THE EAST COAST. COLD AIR ADVECTION WILL
MOVE INTO THE REGION.
TEMPS AND WIND CHILLS WILL PLUNGE TONIGHT AS W-NW WINDS CONTINUE.
WINDS ARE EXPECTED TO GUST UP TO 30 MPH TONIGHT WITH TEMPS IN THE
SINGLE DIGITS TO TEENS. THIS WILL CAUSE WIND CHILL VALUES TO BE
AROUND 5 TO 15 BELOW ACROSS PORTIONS OF THE POTOMAC AND VIRGINIA
HIGHLANDS. A WIND CHILL ADVISORY IS IN EFFECT TONIGHT THROUGH
SATURDAY MORNING FOR THIS REGION.
HIGH PRESSURE WILL MOVE OVERHEAD SATURDAY. W-NW FLOW AT THE SFC WILL
LEAD TO TEMPS REACHING THE TEENS IN THE HIGHLANDS AND 20S ELSEWHERE.
WINDS SHOULD SUBSIDE BY SATURDAY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIPRES WL BE CENTERED ATOP CWFA SAT NGT. W/ MOCLR SKIES...LTL IF ANY
WIND...AND SUBZERO /DEGF/ DEWPTS...CONDS LOOK PRIMED FOR A RAPID
TEMP DROP AFTER SUNSET. FCST BASED ON THAT PREMISE...AND SEE NO
REASON TO ADJUST ATTM. THINK IF THINGS WERE TO GO OFF TRACK...IT
WOULD BE COLDER THAN FCST.
WAA COMMENCES AFTR MIDNGT...AND CONTS THRU SUN-SUN NGT...TIL ELY MON
MRNG. STILL NO SGFNT WX SUNDAY...JUST INCRSG CLDS. GOING FCST HAS
MAXT SUN ABT 7-10 DEGF WARMER THAN SAT. THE LOW DEWPTS SHUD KEEP SUN
EVE DRY AS WELL. THEN THINGS GET INTERESTING.
H5 PTTN WL BE RELATIVELY ZONAL...AS THE ARCTIC AMS WOULD HAVE BEEN
SCOURED OUT OF AREA. MOST S/WV ACTIVITY WL BE IN THE NRN STREAM...
WHICH IS ACRS SRN CNDA. A DRY AND OTRW BENIGN CDFNT ASSOCD W/ ONE OF
THESE VORTS WL BE CROSSING THE GRTLKS SUN NGT. HWVR...THERE IS ALSO
A WK LOW AND PACKET OF MSTR IN THE WRN GLFMEX AT THIS TIME.
CONSIDERING BROAD AREA OF ISENT LIFT...THIS MSTR WL BE DRAWN NWD IN
ADVC OF SAID FNT. THUS PCPN WL BE DVLPG OVNGT FM SW TO NE. WHILE AMS
WL NOT BE AS COLD AS RECENT PAST...ITS STILL WL BE COLD ENUF AT THE
SFC TO BE SUBFRZG...WHICH WUD BE REINFORCED BY EVAPORATION.
MEANWHILE...TEMPS ALOFT WL BE WARMING...W/ A NOSE ABV FRZG. THUS...
THINK THERE WL BE A SMALL WINDOW OF MAYBE PL...BUT OTRW WE/RE
LOOKING AT FZRA TIL SFC TEMPS CAN WARM ENUF. THIS WUD BE
CONVENIENTLY TIMED FOR THE MRNG COMMUTE. DURING THE DAY...THINK
THERE WL BE ENUF OF A PUSH TO GET MOST AREAS ABV FRZG. HV HELD ONLY
COOLER CONDS FOR THE SHEN VLY AND NRN MD BASED ON CLIMO.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
LTST GDNC CYCLE HAS MADE A CONTINUITY SHIFT...PLACING MORE EMPHASIS
ON BLDG HIPRES MON NGT-TUE. THAT KEEPS THE SRN STREAM SUPPRESSED...
AND THUS DRIER. THIS ALSO MEANS COOLER. HV MADE THESE ADJUSTMENTS IN
THE DATABASE. TOO MUCH UNCERTAINTY AFTER THAT...AND HV REVERTED TO
CHC POPS WED-THU.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED TODAY THROUGH SATURDAY. VFR FOR THE REST
OF THE WKND UNDER HIPRES.
MSTR SPREAD NEWD ELY MON MRNG...DURING THE PUSH. W/ AMS IN PLACE
SUBFRZG...THERES A RISK OF FZRA TIL IT CAN BE SCOURED OUT. AS
TYPICAL FOR THIS TIME FRAME...TOO MUCH UNCERTAINTY FOR SPCIFICS...
OTHER THAN TO LEAN ON CLIMO-- DCA/BWI WL CHANGE FIRST AND PSBL
ICINESS MORE STUBBORN AT MRB.
AT THIS PT...TUE LOOKS DRY.
&&
.MARINE...
SW WINDS 15-25 KT AHEAD OF A SFC TROUGH. A LULL IN THE WINDS ARE
POSSIBLE AROUND MIDDAY AS THE TROUGH AXIS MOVES ACROSS THE WATERS
BUT COLD AIR ADVECTION BEHIND THE TROUGH WILL CAUSE WINDS TO
BECOME WESTERLY AND GUST AROUND 20 KTS TONIGHT AND INTO SATURDAY.
A SCA ADVISORY IS IN EFFECT THROUGH SATURDAY MORNING FOR ALL THE
WATERS.
LGT WINDS SAT NGT BCMG SLY SUNDAY. PCPN SPREADS NEWD ELY MON. MAY BE
A LTL ICY TIL TEMPS CAN WARM AND RA TAKES OVER. A CDFNT WL SWEEP
EVERYTHING TO THE E MON NGT. WL BE A SCA POTL POST-FROPA...SPCLY ON
TUE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR MDZ501-502.
VA...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR VAZ503-504.
WV...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR WVZ501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ530>543.
&&
$$
UPDATE...WOODY!
PRVS...HAS/HTS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1016 AM EST FRI JAN 9 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY. ARCTIC HIGH
PRESSURE WILL RETURN FOR TONIGHT AND SATURDAY BEFORE MOVING EAST
SUNDAY. LOW PRESSURE MAY IMPACT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
WIND ADVSRY FOR HIGHER ELEVS IS LOOKING QUITE SUSPECT. HV NOT SEEN
ANY GUSTS INXS OF 40 MPH IN 6 HRS. MAY DROP THE ADVSRY B4 PLANNED
1 PM EXPIRATION.
WE ARE KEEPING EYES ON THE LGT BAND OF SNSH IN ASSO W/ THE CD FNT
APRCHG GARRETT CO. HRRR DOES DEPICTS IT WEAKENING AS IT MOVES E.
PRVS DSCN...
AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE EASTERN CONUS TODAY
WHILE A SHORTWAVE TROUGH DIGS INTO THE OHIO RIVER VALLEY THIS
MORNING. AHEAD OF THE TROUGH...A STRONG SW TO NE ORIENTED LLJ HAS
MOVED INTO THE APPALACHIAN REGION AND SW FLOW HAS LED TO
OVERRUNNING. MOISTURE AND SNOW SHOWERS HAVE BEEN OBSERVED ON
REGIONAL RADAR THIS MORNING.
ELSEWHERE...SW FLOW ALOFT WILL CONTINUE TO CAUSE OVERRUNNING AND
MOISTENING IN THE SNOW GROWTH REGION AS THE SHORTWAVE TROUGH TREKS
EASTWARD THIS MORNING. THIS MAY LEAD TO A LIGHT SNOW SHOWER OR SCT
FLURRIES TO CROSS THE BALTIMORE/WASHINGTON REGION THIS MORNING.
GUIDANCE IS DRY EAST OF THE BLUE RIDGE MTNS INCLUDING ALL SREF
MEMBERS AND THE HRRR HOWEVER AS STATED ABOVE...WEAK LIFT IN THE SNOW
GROWN ZONE AND LITTLE MOISTURE MAY CAUSE SNOW FLAKES TO REACH THE
GROUND. IF THEY DO THEY WILL LIKELY BE SMALL AS DRY AIR AND GUSTY
WINDS WILL BANG THEM UP.
THE SHORTWAVE TROUGH WILL MOVE OFF THE EAST COAST THIS AFTERNOON AND
CLOUDS WILL CLEAR AS SUBSIDENCE MOVES INTO THE REGION. A SFC TROUGH
OR COLD FRONT WILL MOVE ACROSS THE REGION SHORTLY AFTER THE
SHORTWAVE TROUGH MOVES OFF THE EAST COAST. COLD AIR ADVECTION WILL
MOVE INTO THE REGION. FCST MAX TEMPS IN THE TEENS IN THE MTNS AND IN
THE LOW 30S ALONG THE I-95 CORRIDOR ARE EXPECTED THIS AFTERNOON.
TEMPS AND WIND CHILLS WILL TAKE A PLUNGE TONIGHT AS W-NW WINDS
CONTINUE. WINDS ARE EXPECTED TO GUST UP TO 30 MPH TONIGHT WITH TEMPS IN
THE SINGLE DIGITS TO TEENS. THIS WILL CAUSE WIND CHILL VALUES TO
BE AROUND 5 TO 15 BELOW ACROSS PORTIONS OF THE POTOMAC AND
VIRGINIA HIGHLANDS. A WIND CHILL ADVISORY IS IN EFFECT TONIGHT
THROUGH SATURDAY MORNING FOR THIS REGION.
HIGH PRESSURE WILL MOVE OVERHEAD SATURDAY. W-NW FLOW AT THE SFC WILL
LEAD TO TEMPS REACHING THE TEENS IN THE HIGHLANDS AND 20S ELSEWHERE.
WINDS SHOULD SUBSIDE BY SATURDAY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIPRES WL BE CENTERED ATOP CWFA SAT NGT. W/ MOCLR SKIES...LTL IF ANY
WIND...AND SUBZERO /DEGF/ DEWPTS...CONDS LOOK PRIMED FOR A RAPID
TEMP DROP AFTER SUNSET. FCST BASED ON THAT PREMISE...AND SEE NO
REASON TO ADJUST ATTM. THINK IF THINGS WERE TO GO OFF TRACK...IT
WOULD BE COLDER THAN FCST.
WAA COMMENCES AFTR MIDNGT...AND CONTS THRU SUN-SUN NGT...TIL ELY MON
MRNG. STILL NO SGFNT WX SUNDAY...JUST INCRSG CLDS. GOING FCST HAS
MAXT SUN ABT 7-10 DEGF WARMER THAN SAT. THE LOW DEWPTS SHUD KEEP SUN
EVE DRY AS WELL. THEN THINGS GET INTERESTING.
H5 PTTN WL BE RELATIVELY ZONAL...AS THE ARCTIC AMS WOULD HAVE BEEN
SCOURED OUT OF AREA. MOST S/WV ACTIVITY WL BE IN THE NRN STREAM...
WHICH IS ACRS SRN CNDA. A DRY AND OTRW BENIGN CDFNT ASSOCD W/ ONE OF
THESE VORTS WL BE CROSSING THE GRTLKS SUN NGT. HWVR...THERE IS ALSO
A WK LOW AND PACKET OF MSTR IN THE WRN GLFMEX AT THIS TIME.
CONSIDERING BROAD AREA OF ISENT LIFT...THIS MSTR WL BE DRAWN NWD IN
ADVC OF SAID FNT. THUS PCPN WL BE DVLPG OVNGT FM SW TO NE. WHILE AMS
WL NOT BE AS COLD AS RECENT PAST...ITS STILL WL BE COLD ENUF AT THE
SFC TO BE SUBFRZG...WHICH WUD BE REINFORCED BY EVAPORATION.
MEANWHILE...TEMPS ALOFT WL BE WARMING...W/ A NOSE ABV FRZG. THUS...
THINK THERE WL BE A SMALL WINDOW OF MAYBE PL...BUT OTRW WE/RE
LOOKING AT FZRA TIL SFC TEMPS CAN WARM ENUF. THIS WUD BE
CONVENIENTLY TIMED FOR THE MRNG COMMUTE. DURING THE DAY...THINK
THERE WL BE ENUF OF A PUSH TO GET MOST AREAS ABV FRZG. HV HELD ONLY
COOLER CONDS FOR THE SHEN VLY AND NRN MD BASED ON CLIMO.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
LTST GDNC CYCLE HAS MADE A CONTINUITY SHIFT...PLACING MORE EMPHASIS
ON BLDG HIPRES MON NGT-TUE. THAT KEEPS THE SRN STREAM SUPPRESSED...
AND THUS DRIER. THIS ALSO MEANS COOLER. HV MADE THESE ADJUSTMENTS IN
THE DATABASE. TOO MUCH UNCERTAINTY AFTER THAT...AND HV REVERTED TO
CHC POPS WED-THU.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED TODAY THROUGH SATURDAY. SW WINDS 10-20KTS
THIS MORNING. WINDS WILL BECOME W THIS EVENING. GUSTS AROUND
20KTS WILL BE POSSIBLE TONIGHT AND INTO SATURDAY MORNING. HIGH
PRESSURE MOVES INTO THE REGION SATURDAY.
VFR FOR THE REST OF THE WKND UNDER HIPRES.
MSTR SPREAD NEWD ELY MON MRNG...DURING THE PUSH. W/ AMS IN PLACE
SUBFRZG...THERES A RISK OF FZRA TIL IT CAN BE SCOURED OUT. AS
TYPICAL FOR THIS TIME FRAME...TOO MUCH UNCERTAINTY FOR SPCIFICS...
OTHER THAN TO LEAN ON CLIMO-- DCA/BWI WL CHANGE FIRST AND PSBL
ICINESS MORE STUBBORN AT MRB.
AT THIS PT...TUE LOOKS DRY.
&&
.MARINE...
SW WINDS 15-25 KT AHEAD OF A SFC TROUGH. A LULL IN THE WINDS ARE
POSSIBLE AROUND MIDDAY AS THE TROUGH AXIS MOVES ACROSS THE WATERS
BUT COLD AIR ADVECTION BEHIND THE TROUGH WILL CAUSE WINDS TO
BECOME WESTERLY AND GUST AROUND 20 KTS TONIGHT AND INTO SATURDAY.
A SCA ADVISORY IS IN EFFECT THROUGH SATURDAY MORNING FOR ALL THE
WATERS.
LGT WINDS SAT NGT BCMG SLY SUNDAY. PCPN SPREADS NEWD ELY MON. MAY BE
A LTL ICY TIL TEMPS CAN WARM AND RA TAKES OVER. A CDFNT WL SWEEP
EVERYTHING TO THE E MON NGT. WL BE A SCA POTL POST-FROPA...SPCLY ON
TUE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MDZ501-502.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR MDZ501-502.
VA...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ025>027-029-
503-504-507-508.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR VAZ503-504.
WV...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ050-055-
501>506.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR WVZ501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ530>543.
&&
$$
UPDATE...WOODY!
PRVS...HAS/HTS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
503 AM EST FRI JAN 9 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY. ARCTIC HIGH
PRESSURE WILL RETURN FOR TONIGHT AND SATURDAY BEFORE MOVING EAST
SUNDAY. LOW PRESSURE MAY IMPACT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...A WIND CHILL ADVISORY HAS BEEN ISSUED FOR PORTIONS OF THE
VIRGINIA AND POTOMAC HIGHLANDS FOR TONIGHT THROUGH SATURDAY
MORNING. A GALE WARNING IS IN EFFECT THIS MORNING.
DISCUSSION...
AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE EASTERN CONUS TODAY
WHILE A SHORTWAVE TROUGH DIGS INTO THE OHIO RIVER VALLEY THIS MORNING.
AHEAD OF THE TROUGH...A STRONG SW TO NE ORIENTED LLJ HAS MOVED INTO
THE APPALACHIAN REGION AND SW FLOW HAS LED TO OVERRUNNING. MOISTURE
AND SNOW SHOWERS HAVE BEEN OBSERVED ON REGIONAL RADAR THIS
MORNING.
SNOW SHOWERS HAVE BEEN OBSERVED AT THE SFC ACROSS THE GREAT LAKES
REGION AND AREAS NORTH OF THE PA/MD BORDER AS BETTER FORCING AND
HIGHER DEWPTS EXIST IN THIS REGION. RETURNS ON RADAR HAVE BEEN
OBSERVED ACROSS THE POTOMAC HIGHLANDS AND AREAS NEAR THE MASON DIXON
LINE OVERNIGHT. THIS MOISTURE HAS BEEN EVAPORATING AS IT REACHES THE
GROUND AS DEWPT DEPRESSIONS ARE 10-20 DEGREES. THE SHORTWAVE TROUGH
WILL CONTINUE TO MOVE EASTWARD ACROSS THE MID-ATLANTIC THIS MORNING.
THE LLJ AND MIXING HAS ALLOWED STRONG GUSTS TO REACH THE RIDGETOPS
ACROSS THE APPALACHIAN MTNS OVERNIGHT. THIS WILL CONTINUE AS THE JET
MOVES NORTHEASTWARD ACROSS THE REGION. A WIND ADVISORY IS IN EFFECT
FOR THE HIGHER ELEVATIONS MAINLY ABOVE 1500 FEET. GUSTS AROUND 50
MPH ARE POSSIBLE IN THIS REGION. WINDS WILL BECOME WESTERLY BEHIND
THE TROUGH AND WILL CAUSE A UPSLOPE COMPONENT ON THE WESTERN SLOPES.
SNOW SHOWERS WILL CONTINUE THROUGH TODAY IN THIS AREA. AROUND A INCH
OF ACCUMULATION IS EXPECTED FOR THE WESTERN SLOPES.
ELSEWHERE...SW FLOW ALOFT WILL CONTINUE TO CAUSE OVERRUNNING AND
MOISTENING IN THE SNOW GROWTH REGION AS THE SHORTWAVE TROUGH TREKS
EASTWARD THIS MORNING. THIS MAY LEAD TO A LIGHT SNOW SHOWER OR SCT
FLURRIES TO CROSS THE BALTIMORE/WASHINGTON REGION THIS MORNING.
GUIDANCE IS DRY EAST OF THE BLUE RIDGE MTNS INCLUDING ALL SREF
MEMBERS AND THE HRRR HOWEVER AS STATED ABOVE...WEAK LIFT IN THE SNOW
GROWN ZONE AND LITTLE MOISTURE MAY CAUSE SNOW FLAKES TO REACH THE
GROUND. IF THEY DO THEY WILL LIKELY BE SMALL AS DRY AIR AND GUSTY
WINDS WILL BANG THEM UP.
THE SHORTWAVE TROUGH WILL MOVE OFF THE EAST COAST THIS AFTERNOON AND
CLOUDS WILL CLEAR AS SUBSIDENCE MOVES INTO THE REGION. A SFC TROUGH
OR COLD FRONT WILL MOVE ACROSS THE REGION SHORTLY AFTER THE
SHORTWAVE TROUGH MOVES OFF THE EAST COAST. COLD AIR ADVECTION WILL
MOVE INTO THE REGION. FCST MAX TEMPS IN THE TEENS IN THE MTNS AND IN
THE LOW 30S ALONG THE I-95 CORRIDOR ARE EXPECTED THIS AFTERNOON.
TEMPS AND WIND CHILLS WILL TAKE A PLUNGE TONIGHT AS W-NW WINDS
CONTINUE. WINDS ARE EXPECTED TO GUST UP TO 30 MPH TONIGHT WITH TEMPS IN
THE SINGLE DIGITS TO TEENS. THIS WILL CAUSE WIND CHILL VALUES TO
BE AROUND 5 TO 15 BELOW ACROSS PORTIONS OF THE POTOMAC AND
VIRGINIA HIGHLANDS. A WIND CHILL ADVISORY IS IN EFFECT TONIGHT
THROUGH SATURDAY MORNING FOR THIS REGION.
HIGH PRESSURE WILL MOVE OVERHEAD SATURDAY. W-NW FLOW AT THE SFC WILL
LEAD TO TEMPS REACHING THE TEENS IN THE HIGHLANDS AND 20S ELSEWHERE.
WINDS SHOULD SUBSIDE BY SATURDAY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIPRES WL BE CENTERED ATOP CWFA SAT NGT. W/ MOCLR SKIES...LTL IF ANY
WIND...AND SUBZERO /DEGF/ DEWPTS...CONDS LOOK PRIMED FOR A RAPID
TEMP DROP AFTER SUNSET. FCST BASED ON THAT PREMISE...AND SEE NO
REASON TO ADJUST ATTM. THINK IF THINGS WERE TO GO OFF TRACK...IT
WOULD BE COLDER THAN FCST.
WAA COMMENCES AFTR MIDNGT...AND CONTS THRU SUN-SUN NGT...TIL ELY MON
MRNG. STILL NO SGFNT WX SUNDAY...JUST INCRSG CLDS. GOING FCST HAS
MAXT SUN ABT 7-10 DEGF WARMER THAN SAT. THE LOW DEWPTS SHUD KEEP SUN
EVE DRY AS WELL. THEN THINGS GET INTERESTING.
H5 PTTN WL BE RELATIVELY ZONAL...AS THE ARCTIC AMS WOULD HAVE BEEN
SCOURED OUT OF AREA. MOST S/WV ACTIVITY WL BE IN THE NRN STREAM...
WHICH IS ACRS SRN CNDA. A DRY AND OTRW BENIGN CDFNT ASSOCD W/ ONE OF
THESE VORTS WL BE CROSSING THE GRTLKS SUN NGT. HWVR...THERE IS ALSO
A WK LOW AND PACKET OF MSTR IN THE WRN GLFMEX AT THIS TIME.
CONSIDERING BROAD AREA OF ISENT LIFT...THIS MSTR WL BE DRAWN NWD IN
ADVC OF SAID FNT. THUS PCPN WL BE DVLPG OVNGT FM SW TO NE. WHILE AMS
WL NOT BE AS COLD AS RECENT PAST...ITS STILL WL BE COLD ENUF AT THE
SFC TO BE SUBFRZG...WHICH WUD BE REINFORCED BY EVAPORATION.
MEANWHILE...TEMPS ALOFT WL BE WARMING...W/ A NOSE ABV FRZG. THUS...
THINK THERE WL BE A SMALL WINDOW OF MAYBE PL...BUT OTRW WE/RE
LOOKING AT FZRA TIL SFC TEMPS CAN WARM ENUF. THIS WUD BE
CONVENIENTLY TIMED FOR THE MRNG COMMUTE. DURING THE DAY...THINK
THERE WL BE ENUF OF A PUSH TO GET MOST AREAS ABV FRZG. HV HELD ONLY
COOLER CONDS FOR THE SHEN VLY AND NRN MD BASED ON CLIMO.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
LTST GDNC CYCLE HAS MADE A CONTINUITY SHIFT...PLACING MORE EMPHASIS
ON BLDG HIPRES MON NGT-TUE. THAT KEEPS THE SRN STREAM SUPPRESSED...
AND THUS DRIER. THIS ALSO MEANS COOLER. HV MADE THESE ADJUSTMENTS IN
THE DATABASE. TOO MUCH UNCERTAINTY AFTER THAT...AND HV REVERTED TO
CHC POPS WED-THU.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED TODAY THROUGH SATURDAY. A DISTURBANCE WILL
CROSS THE REGION TODAY. A PERIOD OF -SN IS POSSIBLE MAINLY AT
MRB-BWI-MTN THIS MORNING. FORCING IS WEAK AND SFC IS DRY SO ANYTHING
THAT DOES FALL SHOULD STILL LEAD TO P6SM. SW WINDS 15-20KTS G 25-30KT
WILL CONTINUE THIS MORNING. WINDS WILL BECOME W THIS EVENING AND
CONTINUE OVERNIGHT. GUSTS AROUND 20KTS WILL BE POSSIBLE TONIGHT AND
INTO SATURDAY MORNING. HIGH PRESSURE MOVES INTO THE REGION SATURDAY.
VFR FOR THE REST OF THE WKND UNDER HIPRES.
MSTR SPREAD NEWD ELY MON MRNG...DURING THE PUSH. W/ AMS IN PLACE
SUBFRZG...THERES A RISK OF FZRA TIL IT CAN BE SCOURED OUT. AS
TYPICAL FOR THIS TIME FRAME...TOO MUCH UNCERTAINTY FOR SPCIFICS...
OTHER THAN TO LEAN ON CLIMO-- DCA/BWI WL CHANGE FIRST AND PSBL
ICINESS MORE STUBBORN AT MRB.
AT THIS PT...TUE LOOKS DRY.
&&
.MARINE...
SW WINDS HAVE INCREASED ACROSS THE WATERS THIS MORNING AND SOME
MARINE OBS HAVE SHOWN 34-35KTS. A GALE WARNING IS IN EFFECT THIS
MORNING UNTIL 10AM WITH THE EXCEPTION OF THE UPPER TIDAL POTOMAC. THE
GRADIENT SHOULD WEAKEN BY LATE MORNING THEN SCA CONTINUES.
PREV DISCUSSION...
SW WINDS 10-20 G 25-30KT AHEAD OF A SFC TROUGH WILL CONTINUE ON THE
WATERS. THE GRADIENT WILL CONTINUE THIS MORNING AND GUSTY CONDITIONS
WILL CONTINUE. A LULL IN THE WINDS ARE POSSIBLE AROUND MIDDAY AS THE
TROUGH AXIS MOVES ACROSS THE WATERS BUT COLD AIR ADVECTION BEHIND
THE TROUGH WILL CAUSE WINDS TO BECOME WESTERLY AND GUST AROUND 20
KTS TONIGHT AND INTO SATURDAY. A SCA ADVISORY IS IN EFFECT THROUGH
SATURDAY MORNING FOR ALL THE WATERS.
LGT WINDS SAT NGT BCMG SLY SUNDAY. PCPN SPREADS NEWD ELY MON. MAY BE
A LTL ICY TIL TEMPS CAN WARM AND RA TAKES OVER. A CDFNT WL SWEEP
EVERYTHING TO THE E MON NGT. WL BE A SCA POTL POST-FROPA...SPCLY ON
TUE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MDZ501-502.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR MDZ501-502.
VA...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ025>027-029-
503-504-507-508.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR VAZ503-504.
WV...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ050-055-
501>506.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR WVZ501>506.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO NOON EST
SATURDAY FOR ANZ530>534-536>543.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR ANZ530>534-
536>543.
SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ535.
&&
$$
SYNOPSIS...HTS
NEAR TERM...HAS
SHORT TERM...HTS
LONG TERM...HTS
AVIATION...HAS/HTS
MARINE...HAS/HTS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
434 AM EST FRI JAN 9 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY. ARCTIC HIGH
PRESSURE WILL RETURN FOR TONIGHT AND SATURDAY BEFORE MOVING EAST
SUNDAY. LOW PRESSURE MAY IMPACT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATE...A WIND CHILL ADVISORY HAS BEEN ISSUED FOR PORTIONS OF THE
VIRGINIA AND POTOMAC HIGHLANDS FOR TONIGHT THROUGH SATURDAY
MORNING.
DISCUSSION...
AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE EASTERN CONUS TODAY
WHILE A SHORTWAVE TROUGH DIGS INTO THE OHIO RIVER VALLEY THIS MORNING.
AHEAD OF THE TROUGH...A STRONG SW TO NE ORIENTED LLJ HAS MOVED INTO
THE APPALACHIAN REGION AND SW FLOW HAS LED TO OVERRUNNING. MOISTURE
AND SNOW SHOWERS HAVE BEEN OBSERVED ON REGIONAL RADAR THIS
MORNING.
SNOW SHOWERS HAVE BEEN OBSERVED AT THE SFC ACROSS THE GREAT LAKES
REGION AND AREAS NORTH OF THE PA/MD BORDER AS BETTER FORCING AND
HIGHER DEWPTS EXIST IN THIS REGION. RETURNS ON RADAR HAVE BEEN
OBSERVED ACROSS THE POTOMAC HIGHLANDS AND AREAS NEAR THE MASON DIXON
LINE OVERNIGHT. THIS MOISTURE HAS BEEN EVAPORATING AS IT REACHES THE
GROUND AS DEWPT DEPRESSIONS ARE 10-20 DEGREES. THE SHORTWAVE TROUGH
WILL CONTINUE TO MOVE EASTWARD ACROSS THE MID-ATLANTIC THIS MORNING.
THE LLJ AND MIXING HAS ALLOWED STRONG GUSTS TO REACH THE RIDGETOPS
ACROSS THE APPALACHIAN MTNS OVERNIGHT. THIS WILL CONTINUE AS THE JET
MOVES NORTHEASTWARD ACROSS THE REGION. A WIND ADVISORY IS IN EFFECT
FOR THE HIGHER ELEVATIONS MAINLY ABOVE 1500 FEET. GUSTS AROUND 50
MPH ARE POSSIBLE IN THIS REGION. WINDS WILL BECOME WESTERLY BEHIND
THE TROUGH AND WILL CAUSE A UPSLOPE COMPONENT ON THE WESTERN SLOPES.
SNOW SHOWERS WILL CONTINUE THROUGH TODAY IN THIS AREA. AROUND A INCH
OF ACCUMULATION IS EXPECTED FOR THE WESTERN SLOPES.
ELSEWHERE...SW FLOW ALOFT WILL CONTINUE TO CAUSE OVERRUNNING AND
MOISTENING IN THE SNOW GROWTH REGION AS THE SHORTWAVE TROUGH TREKS
EASTWARD THIS MORNING. THIS MAY LEAD TO A LIGHT SNOW SHOWER OR SCT
FLURRIES TO CROSS THE BALTIMORE/WASHINGTON REGION THIS MORNING.
GUIDANCE IS DRY EAST OF THE BLUE RIDGE MTNS INCLUDING ALL SREF
MEMBERS AND THE HRRR HOWEVER AS STATED ABOVE...WEAK LIFT IN THE SNOW
GROWN ZONE AND LITTLE MOISTURE MAY CAUSE SNOW FLAKES TO REACH THE
GROUND. IF THEY DO THEY WILL LIKELY BE SMALL AS DRY AIR AND GUSTY
WINDS WILL BANG THEM UP.
THE SHORTWAVE TROUGH WILL MOVE OFF THE EAST COAST THIS AFTERNOON AND
CLOUDS WILL CLEAR AS SUBSIDENCE MOVES INTO THE REGION. A SFC TROUGH
OR COLD FRONT WILL MOVE ACROSS THE REGION SHORTLY AFTER THE
SHORTWAVE TROUGH MOVES OFF THE EAST COAST. COLD AIR ADVECTION WILL
MOVE INTO THE REGION. FCST MAX TEMPS IN THE TEENS IN THE MTNS AND IN
THE LOW 30S ALONG THE I-95 CORRIDOR ARE EXPECTED THIS AFTERNOON.
TEMPS AND WIND CHILLS WILL TAKE A PLUNGE TONIGHT AS W-NW WINDS
CONTINUE. WINDS ARE EXPECTED TO GUST UP TO 30 MPH TONIGHT WITH TEMPS IN
THE SINGLE DIGITS TO TEENS. THIS WILL CAUSE WIND CHILL VALUES TO
BE AROUND 5 TO 15 BELOW ACROSS PORTIONS OF THE POTOMAC AND
VIRGINIA HIGHLANDS. A WIND CHILL ADVISORY IS IN EFFECT TONIGHT
THROUGH SATURDAY MORNING FOR THIS REGION.
HIGH PRESSURE WILL MOVE OVERHEAD SATURDAY. W-NW FLOW AT THE SFC WILL
LEAD TO TEMPS REACHING THE TEENS IN THE HIGHLANDS AND 20S ELSEWHERE.
WINDS SHOULD SUBSIDE BY SATURDAY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIPRES WL BE CENTERED ATOP CWFA SAT NGT. W/ MOCLR SKIES...LTL IF ANY
WIND...AND SUBZERO /DEGF/ DEWPTS...CONDS LOOK PRIMED FOR A RAPID
TEMP DROP AFTER SUNSET. FCST BASED ON THAT PREMISE...AND SEE NO
REASON TO ADJUST ATTM. THINK IF THINGS WERE TO GO OFF TRACK...IT
WOULD BE COLDER THAN FCST.
WAA COMMENCES AFTR MIDNGT...AND CONTS THRU SUN-SUN NGT...TIL ELY MON
MRNG. STILL NO SGFNT WX SUNDAY...JUST INCRSG CLDS. GOING FCST HAS
MAXT SUN ABT 7-10 DEGF WARMER THAN SAT. THE LOW DEWPTS SHUD KEEP SUN
EVE DRY AS WELL. THEN THINGS GET INTERESTING.
H5 PTTN WL BE RELATIVELY ZONAL...AS THE ARCTIC AMS WOULD HAVE BEEN
SCOURED OUT OF AREA. MOST S/WV ACTIVITY WL BE IN THE NRN STREAM...
WHICH IS ACRS SRN CNDA. A DRY AND OTRW BENIGN CDFNT ASSOCD W/ ONE OF
THESE VORTS WL BE CROSSING THE GRTLKS SUN NGT. HWVR...THERE IS ALSO
A WK LOW AND PACKET OF MSTR IN THE WRN GLFMEX AT THIS TIME.
CONSIDERING BROAD AREA OF ISENT LIFT...THIS MSTR WL BE DRAWN NWD IN
ADVC OF SAID FNT. THUS PCPN WL BE DVLPG OVNGT FM SW TO NE. WHILE AMS
WL NOT BE AS COLD AS RECENT PAST...ITS STILL WL BE COLD ENUF AT THE
SFC TO BE SUBFRZG...WHICH WUD BE REINFORCED BY EVAPORATION.
MEANWHILE...TEMPS ALOFT WL BE WARMING...W/ A NOSE ABV FRZG. THUS...
THINK THERE WL BE A SMALL WINDOW OF MAYBE PL...BUT OTRW WE/RE
LOOKING AT FZRA TIL SFC TEMPS CAN WARM ENUF. THIS WUD BE
CONVENIENTLY TIMED FOR THE MRNG COMMUTE. DURING THE DAY...THINK
THERE WL BE ENUF OF A PUSH TO GET MOST AREAS ABV FRZG. HV HELD ONLY
COOLER CONDS FOR THE SHEN VLY AND NRN MD BASED ON CLIMO.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
LTST GDNC CYCLE HAS MADE A CONTINUITY SHIFT...PLACING MORE EMPHASIS
ON BLDG HIPRES MON NGT-TUE. THAT KEEPS THE SRN STREAM SUPPRESSED...
AND THUS DRIER. THIS ALSO MEANS COOLER. HV MADE THESE ADJUSTMENTS IN
THE DATABASE. TOO MUCH UNCERTAINTY AFTER THAT...AND HV REVERTED TO
CHC POPS WED-THU.
&&
.AVIATION /10Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED TODAY THROUGH SATURDAY. A DISTURBANCE WILL
CROSS THE REGION TODAY. A PERIOD OF -SN IS POSSIBLE MAINLY AT
MRB-BWI-MTN THIS MORNING. FORCING IS WEAK AND SFC IS DRY SO ANYTHING
THAT DOES FALL SHOULD STILL LEAD TO P6SM. SW WINDS 15-20KTS G 25-30KT
WILL CONTINUE THIS MORNING. WINDS WILL BECOME W THIS EVENING AND
CONTINUE OVERNIGHT. GUSTS AROUND 20KTS WILL BE POSSIBLE TONIGHT AND
INTO SATURDAY MORNING. HIGH PRESSURE MOVES INTO THE REGION SATURDAY.
VFR FOR THE REST OF THE WKND UNDER HIPRES.
MSTR SPREAD NEWD ELY MON MRNG...DURING THE PUSH. W/ AMS IN PLACE
SUBFRZG...THERES A RISK OF FZRA TIL IT CAN BE SCOURED OUT. AS
TYPICAL FOR THIS TIME FRAME...TOO MUCH UNCERTAINTY FOR SPCIFICS...
OTHER THAN TO LEAN ON CLIMO-- DCA/BWI WL CHANGE FIRST AND PSBL
ICINESS MORE STUBBORN AT MRB.
AT THIS PT...TUE LOOKS DRY.
&&
.MARINE...
SW WINDS 10-20 G 25-30KT AHEAD OF A SFC TROUGH WILL CONTINUE ON THE
WATERS. THE GRADIENT WILL CONTINUE THIS MORNING AND GUSTY CONDITIONS
WILL CONTINUE. A LULL IN THE WINDS ARE POSSIBLE AROUND MIDDAY AS THE
TROUGH AXIS MOVES ACROSS THE WATERS BUT COLD AIR ADVECTION BEHIND
THE TROUGH WILL CAUSE WINDS TO BECOME WESTERLY AND GUST AROUND 20
KTS TONIGHT AND INTO SATURDAY. A SCA ADVISORY IS IN EFFECT THROUGH
SATURDAY MORNING FOR ALL THE WATERS.
LGT WINDS SAT NGT BCMG SLY SUNDAY. PCPN SPREADS NEWD ELY MON. MAY BE
A LTL ICY TIL TEMPS CAN WARM AND RA TAKES OVER. A CDFNT WL SWEEP
EVERYTHING TO THE E MON NGT. WL BE A SCA POTL POST-FROPA...SPCLY ON
TUE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MDZ501-502.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR MDZ501-502.
VA...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ025>027-029-
503-504-507-508.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR VAZ503-504.
WV...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ050-055-
501>506.
WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
SATURDAY FOR WVZ501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ530>543.
&&
$$
SYNOPSIS...HTS
NEAR TERM...HAS
SHORT TERM...HTS
LONG TERM...HTS
AVIATION...HAS/HTS
MARINE...HAS/HTS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
347 AM EST FRI JAN 9 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY. ARCTIC HIGH
PRESSURE WILL RETURN FOR TONIGHT AND SATURDAY BEFORE MOVING EAST
SUNDAY. LOW PRESSURE MAY IMPACT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE EASTERN CONUS TODAY
WHILE A SHORTWAVE TROUGH DIGS INTO THE OHIO RIVER VALLEY THIS MORNING.
AHEAD OF THE TROUGH...A STRONG SW TO NE ORIENTED LLJ HAS MOVED INTO
THE APPALACHIAN REGION AND SW FLOW HAS LED TO OVERRUNNING. MOISTURE
AND SNOW SHOWERS HAVE BEEN OBSERVED ON REGIONAL RADAR THIS
MORNING.
SNOW SHOWERS HAVE BEEN OBSERVED AT THE SFC ACROSS THE GREAT LAKES
REGION AND AREAS NORTH OF THE PA/MD BORDER AS BETTER FORCING AND
HIGHER DEWPTS EXIST IN THIS REGION. RETURNS ON RADAR HAVE BEEN
OBSERVED ACROSS THE POTOMAC HIGHLANDS AND AREAS NEAR THE MASON DIXON
LINE OVERNIGHT. THIS MOISTURE HAS BEEN EVAPORATING AS IT REACHES THE
GROUND AS DEWPT DEPRESSIONS ARE 10-20 DEGREES. THE SHORTWAVE TROUGH
WILL CONTINUE TO MOVE EASTWARD ACROSS THE MID-ATLANTIC THIS MORNING.
THE LLJ AND MIXING HAS ALLOWED STRONG GUSTS TO REACH THE RIDGETOPS
ACROSS THE APPALACHIAN MTNS OVERNIGHT. THIS WILL CONTINUE AS THE JET
MOVES NORTHEASTWARD ACROSS THE REGION. A WIND ADVISORY IS IN EFFECT
FOR THE HIGHER ELEVATIONS MAINLY ABOVE 1500 FEET. GUSTS AROUND 50
MPH ARE POSSIBLE IN THIS REGION. WINDS WILL BECOME WESTERLY BEHIND
THE TROUGH AND WILL CAUSE A UPSLOPE COMPONENT ON THE WESTERN SLOPES.
SNOW SHOWERS WILL CONTINUE THROUGH TODAY IN THIS AREA. AROUND A INCH
OF ACCUMULATION IS EXPECTED FOR THE WESTERN SLOPES.
ELSEWHERE...SW FLOW ALOFT WILL CONTINUE TO CAUSE OVERRUNNING AND
MOISTENING IN THE SNOW GROWTH REGION AS THE SHORTWAVE TROUGH TREKS
EASTWARD THIS MORNING. THIS MAY LEAD TO A LIGHT SNOW SHOWER OR SCT
FLURRIES TO CROSS THE BALTIMORE/WASHINGTON REGION THIS MORNING.
GUIDANCE IS DRY EAST OF THE BLUE RIDGE MTNS INCLUDING ALL SREF
MEMBERS AND THE HRRR HOWEVER AS STATED ABOVE...WEAK LIFT IN THE SNOW
GROWN ZONE AND LITTLE MOISTURE MAY CAUSE SNOW FLAKES TO REACH THE
GROUND. IF THEY DO THEY WILL LIKELY BE SMALL AS DRY AIR AND GUSTY
WINDS WILL BANG THEM UP.
THE SHORTWAVE TROUGH WILL MOVE OFF THE EAST COAST THIS AFTERNOON AND
CLOUDS WILL CLEAR AS SUBSIDENCE MOVES INTO THE REGION. A SFC TROUGH
OR COLD FRONT WILL MOVE ACROSS THE REGION SHORTLY AFTER THE
SHORTWAVE TROUGH MOVES OFF THE EAST COAST. COLD AIR ADVECTION WILL
MOVE INTO THE REGION. FCST MAX TEMPS IN THE TEENS IN THE MTNS AND IN
THE LOW 30S ALONG THE I-95 CORRIDOR ARE EXPECTED THIS AFTERNOON.
TEMPS AND WIND CHILLS WILL TAKE A PLUNGE TONIGHT AS W-NW WINDS
CONTINUE. A WIND CHILL ADVISORY MAY BE WARRENTED TONIGHT AS WIND
CHILLS APPROACH ZERO AND INTO THE TEENS ACROSS THE HIGHER ELEVATIONS.
HIGH PRESSURE WILL MOVE OVERHEAD SATURDAY. W-NW FLOW AT THE SFC WILL
LEAD TO TEMPS REACHING THE TEENS IN THE HIGHLANDS AND 20S ELSEWHERE.
WINDS SHOULD SUBSIDE BY SATURDAY AFTERNOON.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
HIPRES WL BE CENTERED ATOP CWFA SAT NGT. W/ MOCLR SKIES...LTL IF ANY
WIND...AND SUBZERO /DEGF/ DEWPTS...CONDS LOOK PRIMED FOR A RAPID
TEMP DROP AFTER SUNSET. FCST BASED ON THAT PREMISE...AND SEE NO
REASON TO ADJUST ATTM. THINK IF THINGS WERE TO GO OFF TRACK...IT
WOULD BE COLDER THAN FCST.
WAA COMMENCES AFTR MIDNGT...AND CONTS THRU SUN-SUN NGT...TIL ELY MON
MRNG. STILL NO SGFNT WX SUNDAY...JUST INCRSG CLDS. GOING FCST HAS
MAXT SUN ABT 7-10 DEGF WARMER THAN SAT. THE LOW DEWPTS SHUD KEEP SUN
EVE DRY AS WELL. THEN THINGS GET INTERESTING.
H5 PTTN WL BE RELATIVELY ZONAL...AS THE ARCTIC AMS WOULD HAVE BEEN
SCOURED OUT OF AREA. MOST S/WV ACTIVITY WL BE IN THE NRN STREAM...
WHICH IS ACRS SRN CNDA. A DRY AND OTRW BENIGN CDFNT ASSOCD W/ ONE OF
THESE VORTS WL BE CROSSING THE GRTLKS SUN NGT. HWVR...THERE IS ALSO
A WK LOW AND PACKET OF MSTR IN THE WRN GLFMEX AT THIS TIME.
CONSIDERING BROAD AREA OF ISENT LIFT...THIS MSTR WL BE DRAWN NWD IN
ADVC OF SAID FNT. THUS PCPN WL BE DVLPG OVNGT FM SW TO NE. WHILE AMS
WL NOT BE AS COLD AS RECENT PAST...ITS STILL WL BE COLD ENUF AT THE
SFC TO BE SUBFRZG...WHICH WUD BE REINFORCED BY EVAPORATION.
MEANWHILE...TEMPS ALOFT WL BE WARMING...W/ A NOSE ABV FRZG. THUS...
THINK THERE WL BE A SMALL WINDOW OF MAYBE PL...BUT OTRW WE/RE
LOOKING AT FZRA TIL SFC TEMPS CAN WARM ENUF. THIS WUD BE
CONVENIENTLY TIMED FOR THE MRNG COMMUTE. DURING THE DAY...THINK
THERE WL BE ENUF OF A PUSH TO GET MOST AREAS ABV FRZG. HV HELD ONLY
COOLER CONDS FOR THE SHEN VLY AND NRN MD BASED ON CLIMO.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
LTST GDNC CYCLE HAS MADE A CONTINUITY SHIFT...PLACING MORE EMPHASIS
ON BLDG HIPRES MON NGT-TUE. THAT KEEPS THE SRN STREAM SUPPRESSED...
AND THUS DRIER. THIS ALSO MEANS COOLER. HV MADE THESE ADJUSTMENTS IN
THE DATABASE. TOO MUCH UNCERTAINTY AFTER THAT...AND HV REVERTED TO
CHC POPS WED-THU.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS EXPECTED TODAY THROUGH SATURDAY. A DISTURBANCE WILL
CROSS THE REGION TODAY. A PERIOD OF -SN IS POSSIBLE MAINLY AT
MRB-BWI-MTN THIS MORNING. FORCING IS WEAK AND SFC IS DRY SO ANYTHING
THAT DOES FALL SHOULD STILL LEAD TO P6SM. SW WINDS 15-20KTS G 25-30KT
WILL CONTINUE THIS MORNING. WINDS WILL BECOME W THIS EVENING AND
CONTINUE OVERNIGHT. GUSTS AROUND 20KTS WILL BE POSSIBLE TONIGHT AND
INTO SATURDAY MORNING. HIGH PRESSURE MOVES INTO THE REGION SATURDAY.
VFR FOR THE REST OF THE WKND UNDER HIPRES.
MSTR SPREAD NEWD ELY MON MRNG...DURING THE PUSH. W/ AMS IN PLACE
SUBFRZG...THERES A RISK OF FZRA TIL IT CAN BE SCOURED OUT. AS
TYPICAL FOR THIS TIME FRAME...TOO MUCH UNCERTAINTY FOR SPCIFICS...
OTHER THAN TO LEAN ON CLIMO-- DCA/BWI WL CHANGE FIRST AND PSBL
ICINESS MORE STUBBORN AT MRB.
AT THIS PT...TUE LOOKS DRY.
&&
.MARINE...
SW WINDS 10-20 G 25-30KT AHEAD OF A SFC TROUGH WILL CONTINUE ON THE
WATERS. THE GRADIENT WILL CONTINUE THIS MORNING AND GUSTY CONDITIONS
WILL CONTINUE. A LULL IN THE WINDS ARE POSSIBLE AROUND MIDDAY AS THE
TROUGH AXIS MOVES ACROSS THE WATERS BUT COLD AIR ADVECTION BEHIND
THE TROUGH WILL CAUSE WINDS TO BECOME WESTERLY AND GUST AROUND 20
KTS TONIGHT AND INTO SATURDAY. A SCA ADVISORY IS IN EFFECT THROUGH
SATURDAY MORNING FOR ALL THE WATERS.
LGT WINDS SAT NGT BCMG SLY SUNDAY. PCPN SPREADS NEWD ELY MON. MAY BE
A LTL ICY TIL TEMPS CAN WARM AND RA TAKES OVER. A CDFNT WL SWEEP
EVERYTHING TO THE E MON NGT. WL BE A SCA POTL POST-FROPA...SPCLY ON
TUE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MDZ501-502.
VA...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ025>027-029-
503-504-507-508.
WV...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ050-055-
501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SATURDAY FOR ANZ530>543.
&&
$$
SYNOPSIS...HTS
NEAR TERM...HAS
SHORT TERM...HTS
LONG TERM...HTS
AVIATION...HAS/HTS
MARINE...HAS/HTS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
951 PM EST SAT JAN 10 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 320 PM EST SAT JAN 10 2015
A SLIGHT WARM UP IS ON THE WAY FOR THIS COMING WEEK. AS THE WARM
AIR STARTS TO MOVE IN TONIGHT THERE WILL BE A PERIOD OF LIGHT SNOW
SHOWERS...MOSTLY NORTH AND WEST OF GRAND RAPIDS. ANOTHER PERIOD OF
LIGHT SNOW WILL CROSS AREAS NEAR AND SOUTH OF INTERSTATE 96 SUNDAY
NIGHT AS THE COLD AIR ONCE AGAIN TRIES TO PUSH BACK SOUTHWARD. AS
OUR LAST POLAR ORIGIN HIGH OF THIS CURRENT WEATHER PATTERN MOVES
IN MONDAY SKIES WILL BE MOSTLY CLOUDY BUT WILL SEE CLEARING LATE
IN THE DAY. WITH THE HIGH OVERHEAD ON TUESDAY EXPECT MOSTLY SUNNY
SKIES AND VERY COLD TEMPERATURES FOR ONE MORE DAY. LOW WILL BE BELOW
ZERO IN MOST AREAS THAT NIGHT. BEY0ND THAT A SLOW WARM UP BEGINS. BY
NEXT SATURDAY WE MAY HAVE HIGH ABOVE FREEZING.
&&
.UPDATE...
ISSUED AT 951 PM EST SAT JAN 10 2015
WILL REDUCE POPS TO CHANCE OR SLIGHT CHANCE EVERYWHERE OVERNIGHT. A
LOT OF SHEAR IS SHOWING UP IN THE PROFILES WHICH IS REDUCING THE
LAKE ENHANCEMENT. ANY SNOW SHOULD REMAIN WITH LESS THAN AN INCH OF
ACCUMULATION POSSIBLE OVER PARTS OF THE NW CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 320 PM EST SAT JAN 10 2015
WE HAVE THE DEPARTING OF THE WEEK LONG COLD PATTERN UNDERWAY AS I
WRITE THIS. THIS WAS THE LONGEST STRING OF DAYS IN A ROW WITH
HIGHS BELOW 20 DEGREES IN GRAND RAPIDS SINCE THE MIDDLE OF
FEBRUARY IN 2007. THIS WILL BE HISTORY ON SUNDAY.
AS THE WARM AIR SURGES IN TONIGHT... EVEN WITH VERY FEEBLE
MOISTURE (PRECIPITABLE WATER SURGES TO A THIRD OF AN INCH/ 75TH
PERCENTILE)...SOME LIGHT SNOW IS EXPECTED WEST OF US-131 AND NORTH
OF GRAND RAPIDS DURING THE EARLY TO MID EVENING. THIS IS SHOWN BY
THE NAM... GFS... ECMWF... HRRR AND RAP MODELS TO VARYING DEGREES.
THERE IS A SURFACE BASED THERMAL BOUNDARY (20 DEGREE HOLLAND / 12AT
GRAND RAPIDS) CURRENTLY LOCATED FROM SOUTH HAVEN TO NEAR GRAND
RAPIDS TO NEAR MOUNT PLEASANT. THIS IS CURRENTLY FOCUSING SNOW
SHOWERS NEAR THE LAKE SHORE AND HELP FOCUS THE SNOW SHOWERS WITH
WARM AIR PUSH TONIGHT. ALSO HELPING THIS EVENT TOO IS THE LIFT
ASSOCIATED WITH THE ENTRANCE REGION TO DEPARTING UPPER LEVEL JET
CORE. THERE IS A 3 HOUR WINDOW WHERE OUR NORTHWEST CWA WILL HAVE
SOLID NEAR SATURATED AIR FROM AROUND 1000 FT AGL TO NEAR 10,000 FT
AGL. GIVEN HOW COLD IT IS...THAT IS MORE THAN ENOUGH TO LEAD TO
LIGHT SNOW SHOWERS.
ONCE THAT IS DONE SUNDAY NIGHT WE GET THE INTERPLAY OF THAT SAME
JET EXIT REGION WITH EXIT REGION OF JET CORE LIFTING NORTHWARD
FROM A SOUTHERN STREAM WAVE. THIS RESULTS IN A COUPLED JET AND THE
PRECIPITABLE WATER SURGES EVEN HIGHER TO NEARLY A HALF INCH WITH IS
ABOUT DOUBLE NORMAL. SO I AM THINKING LIGHT SNOW IS MORE THAN
LIKELY SOUTH OF INTERSTATE 96 SUNDAY NIGHT. IT IS MY EXPERIENCE
THAT THIS SORT OF EVENT NEARLY ALWAYS RESULTS IN MEASURABLE
PRECIPITATION SO I HAVE HIGH CONFIDENCE THERE WILL BE LIGHT SNOW
ALONG THE I-94 CORRIDOR SUNDAY NIGHT.
ONCE THAT IS DONE A JET CORE ON THE NORTHERN STREAM...DIVING DUE
SOUTHEAST FROM THE NORTHERN ARCTIC TOWARD HUDSON BY TUESDAY BRINGS
US OUR LAST SURGE OF VERY COLD AIR FOR TUESDAY. SINCE THE JET CORE
THIS TIME WILL BE WELL NORTH OF MICHIGAN THIS WILL BE SHALLOW COLD
AIR AND WINDS AT THE SURFACE WILL BE NORTHEAST SO WE GET TO SEE
MOSTLY SUNNY SKIES FOR A CHANGE! EVEN SO WITH SNOW ON THE GROUND
OVER MOST OF THE AREA IT WILL BE VERY COLD ONE LAST DAY.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT JAN 10 2015
THE LONG TERM PORTION OF THE FCST LOOKS TO BE VERY QUIET FOR THIS
TIME OF THE YEAR. WE WILL START OFF WITH A COLD MORNING AT THE
BEGINNING OF THE PERIOD...AND THEN MODERATE AT THE END OF THE PERIOD.
WE WILL SEE A VERY COLD MORNING TUE MORNING AND AGAIN ON TUE
NIGHT/WED MORNING. HIGH PRESSURE PROVIDING A LIGHT GRADIENT AND
MAINLY CLEAR SKIES...WILL COMBINE WITH OUR SNOW PACK TO ALLOW MOST
TEMPS TO DROP BELOW ZERO TUE MORNING AND WED MORNING.
SOME MODERATION IN TEMPS WILL TAKE PLACE FOR WED AND THU AS RETURN
FLOW FROM THE WSW WILL SET UP OVER THE AREA. HIGH PRESSURE WILL DROP
SOUTH...AND WE WILL EVENTUALLY SEE A COLD FRONT TRY TO APPROACH THE
AREA FROM THE NW. TOUGH TO TELL HOW FAR SOUTH THIS FRONT WILL MAKE
IT...BUT IT COULD BRING A LOW CHC OF SNOW TO THE NRN PORTION OF THE
AREA ON THU. THE FRONTAL POSITION WILL ALSO DICTATE HOW WARM WE GET.
THE GFS TAKES IT A BIT FURTHER SOUTH WHILE THE EURO HOLDS IT UP
NORTH OF THE AREA.
THE BEST MODERATION IN TEMPS WILL COME AT THE END OF THE PERIOD.
AFTER THE THU SYSTEM MOVES BY...WE WILL GET BACK INTO A RETURN FLOW
PATTERN ONCE AGAIN. A ZONAL FLOW ALOFT WILL KEEP THE COLD AIR AND
WAVES OF LOW PRESSURE FAR ENOUGH NORTH TO KEEP OUR AREA DRY. WE
SHOULD SEE TEMPS AT LEAST GET INTO THE 30S BY NEXT SAT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 631 PM EST SAT JAN 10 2015
LIGHT SNOW WILL BRING SOME PATCHY AREAS OF 3 TO 5 MILES VISBYS AND
CEILINGS IN THE 2500FT RANGE TONIGHT. EXPECT MOSTLY VFR CONDITIONS
TO PREVAIL ON SUNDAY. SOUTHWEST WINDS AROUND 10 TO 15 KNOTS THIS
EVENING WILL DECREASE GRADUALLY OVERNIGHT.
&&
.MARINE...
ISSUED AT 320 PM EST SAT JAN 10 2015
I WILL ALLOW THE FREEZING SPRAY WARNING TO CONTINUE THROUGH 7 PM
AS WINDS ARE NEAR 25 KNOTS OVER THE WATER AND TEMPERATURES WERE IN
THE TEENS. SEEMS THAT TEMPERATURES WILL RISE INTO THE 20S IN THE
NEAR SHORE THIS EVENING ALLOWING US TO LET THE WARNING EXPIRE ON
TIME. WINDS WILL REMAIN STRONG ENOUGH FOR SMALL CRAFT INTO SUNDAY.
WE WILL HAVE TO WATCH TO SEE HOW MUCH THE ICE GROWS. THANKS TO
GLERL WE KNOW THERE IS ABOUT 22% ICE COVERAGE ON LAKE MICHIGAN NOW
AND THAT IF FORECAST TO INCREASE INTO THE MIDDLE OF NEXT WEEK.
&&
.HYDROLOGY...
ISSUED AT 320 PM EST SAT JAN 10 2015
LITTLE CHANGE SINCE YESTERDAY. CONTINUED THE FLOOD ADVISORY FOR THE
FLAT RIVER NEAR SMYRNA AS IT SHOULD REMAIN ABOVE BANKFULL INTO NEXT
WEEK. A COUPLE RIVERS REMAIN NEAR BUT UNDER BANKFULL AND WILL HAVE
TO BE MONITORED. FREEZE UP ICE JAMS MAY CAUSE FLUCTUATIONS IN RIVER
LEVELS INTO NEXT WEEK... BUT SERIOUS FLOODING IS NOT MUCH OF A
CONCERN UNTIL SNOWMELT AND ICE BREAKUP HAPPENS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...JK
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
647 PM EST SAT JAN 10 2015
.AVIATION...
HIGH CLOUDS WILL LOWER DURING THE EVENING BUT REMAIN VFR ABOVE 5000
FEET. RADAR RETURNS INCREASING DURING THIS TIME AS WELL WILL PROVE
TO BE MOSTLY VIRGA WITH ONLY A FLURRY ABLE TO REACH THE GROUND IN
ISOLATED LOCATIONS. EARLY EVENING OBSERVATIONAL TRENDS ALSO POINT TO
MVFR LAKE CLOUDS NEARBY TO THE NORTH OF MBS BUT LOW LEVEL FLOW HAS
TURNED SOUTHWEST ENOUGH TO KEEP BUT A FEW PATCHES OF STRATOCU FROM
AFFECTING THAT AREA. EXPECT VFR TO PERSIST OVERNIGHT THROUGH SUNDAY
UNTIL SNOW MOVES IN WITH THE NEXT SYSTEM TOWARD SUNDAY EVENING.
FOR DTW... OBSERVATIONS STILL SUPPORT EXPECTATIONS FOR THE INBOUND
LOWER CLOUD DECK TO REMAIN ABOVE 5000 FT AS IT ENTERS THE TERMINAL
AIRSPACE DURING THE EVENING. THERE COULD BE A FEW FLURRIES WITH THIS
MOISTURE WITH NO IMPACT ON OPERATIONS. SNOW IS EXPECTED TO DEVELOP
LATE SUNDAY AFTERNOON THROUGH SUNDAY NIGHT.
//DTW THRESHOLD PROBABILITIES...
* NONE.
&&
.PREV DISCUSSION...ISSUED 334 PM EST SAT JAN 10 2015
SHORT TERM...TONIGHT
SE MICHIGAN WILL EASE INTO MORE OF A QUASI-ZONAL SLIGHTLY CONFLUENT
MID LEVEL FLOW TONIGHT...BASE OF THE PREDOMINANT CENTRAL CANADIAN
TROUGH DICTATING CONDITIONS RECENTLY FINALLY RELEASING NORTH AND
EAST. A TRANSITION TOWARD LOW LEVEL SOUTH-SOUTHWEST FLOW WILL
INITIATE THE EARLY STAGES OF A PERIOD OF WARM AIR ADVECTION THAT
WILL PERSIST THROUGH THE REMAINDER OF THE WEEKEND. VERY LIMITED
MOISTURE RETURN NOTED UPSTREAM THIS AFTERNOON WITHIN THE ENSUING
BROADENING ISENTROPIC ASCENT TIED TO THIS PROCESS. DESPITE THE
GENERAL WARMING THROUGH THE THERMAL PROFILE...THERE WILL REMAIN SOME
PERPETUATION OF THE ONGOING WEAK LAKE MOISTURE FLUX. THIS WILL
CONTRIBUTE SLIGHTLY TO THE OVERALL MOISTURE QUALITY NORTH OF THE I-
69 CORRIDOR... PROVIDING A WINDOW FOR SOME ADDITIONAL LIGHT SNOW
SHOWER DEVELOPMENT TONIGHT. ELSEWHERE LITTLE MORE THAN
FLURRIES...RECENT NAM AND RAP SOUNDING DATA STILL LEAVE A HEALTHY
DRY LAYER WITHIN THE LOWEST 4000 FT THROUGH THE NIGHT.
EXISTING ENVIRONMENT REMAINS FAVORABLE FOR A GOOD NOCTURNAL COOLING
RESPONSE THIS EVENING...PARTICULARLY SOUTHERN/CENTRAL SECTIONS WHERE
SKIES ARE NOW CLEAR. THIS WILL BRING LOWS IN MANY LOCALES INTO THE
SINGLE DIGITS EARLY TONIGHT. A THICKENING CLOUD DECK AND SOME
INCREASE IN THE SOUTHWEST GRADIENT WILL THEN ALLOW TEMPERATURES TO
RISE GRADUALLY HEADING INTO THE EARLY MORNING PERIOD. TEMPERATURES
BACK INTO LOW-MID TEENS BY DAYBREAK.
LONG TERM...
THE SQUEEZE PLAY LOOKS TO BE ON LATE TOMORROW/TOMORROW NIGHT AS
UPPER WAVE AND ASSOCIATED MOISTURE OVER TEXAS MAKES A RUN NORTHEAST
TOWARD THE CENTRAL GREAT LAKES. AT THE SAME TIME...ANOTHER STRONG
NORTHERN STREAM TROUGH WILL BE DROPPING SOUTHEAST FROM CENTRAL
CANADA. THE TROUGH AXIS IS DISTINCTLY POSITIVELY TILTED AND WILL ACT
TO SHUNT/SHEAR OUT THE WAVE TO OUR SOUTH. REASONABLE AGREEMENT WITH
SUFFICIENT MOISTURE TRANSPORT SNEAKING ACROSS THE MICHIGAN BORDER TO
SUPPORT SOME LIGHT SNOW...AS 850-700 MB SPECIFIC HUMIDITY OF 3+ G/KG
SEEN REACHING THE M-59 CORRIDOR (REGIONAL GEM/GFS) OR EVEN AS FAR
NORTH AS THE I-69 CORRIDOR (NAM). THERMAL PROFILES ARE NOT IDEAL FOR
HIGH SNOW TO LIQUID RATIOS HOWEVER. FORCING FROM ISENTROPIC ASCENT
PROSPECTIVE IS NOT VERY AGGRESSIVE...AND BEST 850 MB FGEN LOOKS TO
BE OCCURRING AT OR JUST SOUTH OF THE MICHIGAN BORDER. NOT MUCH OF A
SURFACE REFLECTION AS WELL. THIS APPEARS TO BE A 1 TO 2 INCH
SNOWFALL FOR MOST OF SOUTHEAST MICHIGAN (FOCUSED M-59 SOUTH) BY THE
TIME THE SNOW ENDS MONDAY MORNING. 925 MB TEMPS PROGGED TO RISE TO
AROUND -5 C...BUT BOUNDARY LAYER DEPTH WILL FAIL TO REACH THIS
LEVEL...AND A SLOW GRIND INTO THE 20S FOR HIGHS EXPECTED
TOMORROW...WITH TEMPS HOLDING NEARLY STEADY SUNDAY EVENING/NIGHT
WITH THE INCREASE IN MOISTURE AND SNOW. SURPRISINGLY...NORTHERN
STREAM TROUGH LOOKS TO BE PROVIDING ONLY A GLANCING BLOW WITH THE
COLD AIR...AS 850 MB TEMPS PROGGED TO DROP INTO MID NEGATIVE TEENS
(PER 12Z EURO)...WITH DRY AIR/SUBSIDENCE WINNING OUT AT THIS
LEVEL...WITH RH DROPPING BELOW 50 PERCENT. STILL...WITH LONG FETCH
NORTHERLY FLOW DEVELOPING OVER LAKE HURON ON MONDAY...ENOUGH COLD
AIR/INSTABILITY/SATURATION AT THE 925 MB LEVEL TO GENERATE SOME SNOW
SHOWERS...PROBABLY BRUSHING THE LAKE HURON SHORELINE...BUT THE
SHALLOW NATURE IS EXPECTED TO LIMIT THE INTENSITY. LOW LEVEL WINDS
EVEN BECOME LIGHT NORTHEAST/ONSHORE BY MONDAY EVENING...BUT AGAIN
WITH THE AMOUNT OF DRY AIR AROUND AND SHALLOW NATURE...SHOULD LIMIT
ACTIVITY TO SCATTERED LIGHT SNOW SHOWERS...WITH JUST LIGHT
ACCUMULATIONS EXPECTED OVER THE NORTHERN THUMB REGION.
SPLIT FLOW ALOFT AND STABLE COLD ANTICYCLONE AT THE SURFACE WILL
LEAD TO COLD AND DRY WEATHER TUESDAY AND WEDNESDAY. WITH SNOW PACK
AND LIGHT WINDS WE COULD SEE TEMPS TANK PRETTY WELL TUESDAY NIGHT
PROVIDED ENOUGH CLEARING TAKES PLACE. THE COLD AIRMASS BEGINS TO
SCOUR OUT A BIT THURSDAY AS SURFACE PRESSURE GRADIENT TIGHTENS AHEAD
OF INCOMING UPPER TROUGH. FRONTAL PASSAGE LATE THURSDAY COULD LEAD
TO A FEW LIGHT SNOW SHOWERS...BUT IT WILL BE MOISTURE STARVED SO
WILL KEEP POPS OUT FOR NOW. PROGRESSIVE NATURE OF THE TROUGH WILL
ALLOW RISING HEIGHTS AND WARM AIR ADVECTION FRIDAY WITH TEMPERATURES
POSSIBLY FINALLY APPROACHING NORMAL BY NEXT WEEKEND.
MARINE...
COLD SOUTHWEST FLOW OVER THE CENTRAL GREAT LAKES THIS AFTERNOON
LEADING TO SUSTAINED WINDS OF 20 TO 30 KNOTS OVER LAKE HURON AS THE
AREA IS SANDWICHED IN BETWEEN LOW PRESSURE OVER ONTARIO AND HIGH
PRESSURE ALONG THE OHIO RIVER. A MARGINAL GUST TO GALES REMAIN
POSSIBLE FOR ANOTHER FEW HOURS AND WILL EXTEND HEAVY FREEZING
WARNING INTO THE EVENING...BUT THE HIGH WILL BE SLOWING EXITING
EAST...ALLOWING THE PRESSURE GRADIENT TO RELAX AS WE HEAD INTO
TONIGHT AND ESPECIALLY TOMORROW...AS ANOTHER ARCTIC COLD FRONT
APPROACHES. THIS FRONT WILL SLIDE THROUGH TOMORROW NIGHT INTO
MONDAY...LEADING TO NORTHERLY WINDS OVER LAKE HURON. THE ARCTIC AIR
IN THE WAKE OF THIS FRONT WILL BE MORE SHALLOW...THUS REDUCING
MIXING DEPTHS...WITH GUSTS ONLY UP TO 30 KNOTS EXPECTED DURING
MONDAY. WINDS WILL DECREASE RAPIDLY MONDAY EVENING/NIGHT AS STRONG
HIGH PRESSURE SETTLES OVER THE ENTIRE GREAT LAKES REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR
LHZ362-363-462>464.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LHZ421-441.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
SHORT TERM...MR
LONG TERM....SF/DT
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
631 PM EST SAT JAN 10 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 320 PM EST SAT JAN 10 2015
A SLIGHT WARM UP IS ON THE WAY FOR THIS COMING WEEK. AS THE WARM
AIR STARTS TO MOVE IN TONIGHT THERE WILL BE A PERIOD OF LIGHT SNOW
SHOWERS...MOSTLY NORTH AND WEST OF GRAND RAPIDS. ANOTHER PERIOD OF
LIGHT SNOW WILL CROSS AREAS NEAR AND SOUTH OF INTERSTATE 96 SUNDAY
NIGHT AS THE COLD AIR ONCE AGAIN TRIES TO PUSH BACK SOUTHWARD. AS
OUR LAST POLAR ORIGIN HIGH OF THIS CURRENT WEATHER PATTERN MOVES
IN MONDAY SKIES WILL BE MOSTLY CLOUDY BUT WILL SEE CLEARING LATE
IN THE DAY. WITH THE HIGH OVERHEAD ON TUESDAY EXPECT MOSTLY SUNNY
SKIES AND VERY COLD TEMPERATURES FOR ONE MORE DAY. LOW WILL BE BELOW
ZERO IN MOST AREAS THAT NIGHT. BEY0ND THAT A SLOW WARM UP BEGINS. BY
NEXT SATURDAY WE MAY HAVE HIGH ABOVE FREEZING.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 320 PM EST SAT JAN 10 2015
WE HAVE THE DEPARTING OF THE WEEK LONG COLD PATTERN UNDERWAY AS I
WRITE THIS. THIS WAS THE LONGEST STRING OF DAYS IN A ROW WITH
HIGHS BELOW 20 DEGREES IN GRAND RAPIDS SINCE THE MIDDLE OF
FEBRUARY IN 2007. THIS WILL BE HISTORY ON SUNDAY.
AS THE WARM AIR SURGES IN TONIGHT... EVEN WITH VERY FEEBLE
MOISTURE (PRECIPITABLE WATER SURGES TO A THIRD OF AN INCH/ 75TH
PERCENTILE)...SOME LIGHT SNOW IS EXPECTED WEST OF US-131 AND NORTH
OF GRAND RAPIDS DURING THE EARLY TO MID EVENING. THIS IS SHOWN BY
THE NAM... GFS... ECMWF... HRRR AND RAP MODELS TO VARYING DEGREES.
THERE IS A SURFACE BASED THERMAL BOUNDARY (20 DEGREE HOLLAND / 12AT
GRAND RAPIDS) CURRENTLY LOCATED FROM SOUTH HAVEN TO NEAR GRAND
RAPIDS TO NEAR MOUNT PLEASANT. THIS IS CURRENTLY FOCUSING SNOW
SHOWERS NEAR THE LAKE SHORE AND HELP FOCUS THE SNOW SHOWERS WITH
WARM AIR PUSH TONIGHT. ALSO HELPING THIS EVENT TOO IS THE LIFT
ASSOCIATED WITH THE ENTRANCE REGION TO DEPARTING UPPER LEVEL JET
CORE. THERE IS A 3 HOUR WINDOW WHERE OUR NORTHWEST CWA WILL HAVE
SOLID NEAR SATURATED AIR FROM AROUND 1000 FT AGL TO NEAR 10,000 FT
AGL. GIVEN HOW COLD IT IS...THAT IS MORE THAN ENOUGH TO LEAD TO
LIGHT SNOW SHOWERS.
ONCE THAT IS DONE SUNDAY NIGHT WE GET THE INTERPLAY OF THAT SAME
JET EXIT REGION WITH EXIT REGION OF JET CORE LIFTING NORTHWARD
FROM A SOUTHERN STREAM WAVE. THIS RESULTS IN A COUPLED JET AND THE
PRECIPITABLE WATER SURGES EVEN HIGHER TO NEARLY A HALF INCH WITH IS
ABOUT DOUBLE NORMAL. SO I AM THINKING LIGHT SNOW IS MORE THAN
LIKELY SOUTH OF INTERSTATE 96 SUNDAY NIGHT. IT IS MY EXPERIENCE
THAT THIS SORT OF EVENT NEARLY ALWAYS RESULTS IN MEASURABLE
PRECIPITATION SO I HAVE HIGH CONFIDENCE THERE WILL BE LIGHT SNOW
ALONG THE I-94 CORRIDOR SUNDAY NIGHT.
ONCE THAT IS DONE A JET CORE ON THE NORTHERN STREAM...DIVING DUE
SOUTHEAST FROM THE NORTHERN ARCTIC TOWARD HUDSON BY TUESDAY BRINGS
US OUR LAST SURGE OF VERY COLD AIR FOR TUESDAY. SINCE THE JET CORE
THIS TIME WILL BE WELL NORTH OF MICHIGAN THIS WILL BE SHALLOW COLD
AIR AND WINDS AT THE SURFACE WILL BE NORTHEAST SO WE GET TO SEE
MOSTLY SUNNY SKIES FOR A CHANGE! EVEN SO WITH SNOW ON THE GROUND
OVER MOST OF THE AREA IT WILL BE VERY COLD ONE LAST DAY.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT JAN 10 2015
THE LONG TERM PORTION OF THE FCST LOOKS TO BE VERY QUIET FOR THIS
TIME OF THE YEAR. WE WILL START OFF WITH A COLD MORNING AT THE
BEGINNING OF THE PERIOD...AND THEN MODERATE AT THE END OF THE PERIOD.
WE WILL SEE A VERY COLD MORNING TUE MORNING AND AGAIN ON TUE
NIGHT/WED MORNING. HIGH PRESSURE PROVIDING A LIGHT GRADIENT AND
MAINLY CLEAR SKIES...WILL COMBINE WITH OUR SNOW PACK TO ALLOW MOST
TEMPS TO DROP BELOW ZERO TUE MORNING AND WED MORNING.
SOME MODERATION IN TEMPS WILL TAKE PLACE FOR WED AND THU AS RETURN
FLOW FROM THE WSW WILL SET UP OVER THE AREA. HIGH PRESSURE WILL DROP
SOUTH...AND WE WILL EVENTUALLY SEE A COLD FRONT TRY TO APPROACH THE
AREA FROM THE NW. TOUGH TO TELL HOW FAR SOUTH THIS FRONT WILL MAKE
IT...BUT IT COULD BRING A LOW CHC OF SNOW TO THE NRN PORTION OF THE
AREA ON THU. THE FRONTAL POSITION WILL ALSO DICTATE HOW WARM WE GET.
THE GFS TAKES IT A BIT FURTHER SOUTH WHILE THE EURO HOLDS IT UP
NORTH OF THE AREA.
THE BEST MODERATION IN TEMPS WILL COME AT THE END OF THE PERIOD.
AFTER THE THU SYSTEM MOVES BY...WE WILL GET BACK INTO A RETURN FLOW
PATTERN ONCE AGAIN. A ZONAL FLOW ALOFT WILL KEEP THE COLD AIR AND
WAVES OF LOW PRESSURE FAR ENOUGH NORTH TO KEEP OUR AREA DRY. WE
SHOULD SEE TEMPS AT LEAST GET INTO THE 30S BY NEXT SAT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 631 PM EST SAT JAN 10 2015
LIGHT SNOW WILL BRING SOME PATCHY AREAS OF 3 TO 5 MILES VISBYS AND
CEILINGS IN THE 2500FT RANGE TONIGHT. EXPECT MOSTLY VFR CONDITIONS
TO PREVAIL ON SUNDAY. SOUTHWEST WINDS AROUND 10 TO 15 KNOTS THIS
EVENING WILL DECREASE GRADUALLY OVERNIGHT.
&&
.MARINE...
ISSUED AT 320 PM EST SAT JAN 10 2015
I WILL ALLOW THE FREEZING SPRAY WARNING TO CONTINUE THROUGH 7 PM
AS WINDS ARE NEAR 25 KNOTS OVER THE WATER AND TEMPERATURES WERE IN
THE TEENS. SEEMS THAT TEMPERATURES WILL RISE INTO THE 20S IN THE
NEAR SHORE THIS EVENING ALLOWING US TO LET THE WARNING EXPIRE ON
TIME. WINDS WILL REMAIN STRONG ENOUGH FOR SMALL CRAFT INTO SUNDAY.
WE WILL HAVE TO WATCH TO SEE HOW MUCH THE ICE GROWS. THANKS TO
GLERL WE KNOW THERE IS ABOUT 22% ICE COVERAGE ON LAKE MICHIGAN NOW
AND THAT IF FORECAST TO INCREASE INTO THE MIDDLE OF NEXT WEEK.
&&
.HYDROLOGY...
ISSUED AT 320 PM EST SAT JAN 10 2015
LITTLE CHANGE SINCE YESTERDAY. CONTINUED THE FLOOD ADVISORY FOR THE
FLAT RIVER NEAR SMYRNA AS IT SHOULD REMAIN ABOVE BANKFULL INTO NEXT
WEEK. A COUPLE RIVERS REMAIN NEAR BUT UNDER BANKFULL AND WILL HAVE
TO BE MONITORED. FREEZE UP ICE JAMS MAY CAUSE FLUCTUATIONS IN RIVER
LEVELS INTO NEXT WEEK... BUT SERIOUS FLOODING IS NOT MUCH OF A
CONCERN UNTIL SNOWMELT AND ICE BREAKUP HAPPENS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
938 PM CST Sat Jan 10 2015
.UPDATE:
Issued at 916 PM CST Sat Jan 10 2015
Temperatures have been slow to drop this evening due to southerly
winds and mid level clouds advecting northeastward through much of
the area, particularly southeast MO into southwest IL. The
operational models keep the precipitation out of our forecast area
until after 12Z Sunday. The latest HRRR model does bring some
light precipitation into our area already between 10-12Z Sunday,
but this is likely too early with an initially dry surface and
boundary layer. The precipitation may begin as sleet due to
evaporative cooling with very low surface dew points, but should
transition to freezing rain later in the morning with a pronounced
elevated warm layer.
GKS
&&
.SHORT TERM: (Through Late Tonight)
Issued at 333 PM CST Sat Jan 10 2015
The latest data suggests that the weather tonight should be rather
tranquil but seasonably cold. Heights aloft will be on the rise as
the eastern U.S. trof departs and short wave ridging increases ahead
of the lifting west TX upper low trof. In response the gradual
backing of the mid/upper level flow will allow clouds/moisture to
beginning spread into the area, especially overnight.
Glass
.LONG TERM: (Sunday through Next Saturday)
Issued at 333 PM CST Sat Jan 10 2015
Present indications are the winter weather event still remains on
track Sunday into Sunday night. Although the aforementioned
lifting upper low/trof will be weakening, it will spread weak
large scale ascent across the area Sunday into early Sunday
evening. This combined with ascent via low level warm advection
will allow precipitation to spread and develop northward from the
lower MS Valley into Missouri on Sunday morning. The primary
thrust will be across the southeast third of the CWA -
southeast/east central MO into southern IL. I am anticipating the
bulk of the precipitation to be in liquid form aka freezing rain.
Model soundings in this region show a deepening and strengthening
elevated warm layer, thus any sleet should occur in a small window
near the onset of the precipitation. Surface temperatures during
the day on Sunday will actually be warming in response to the low
level warm advection and will hover near freezing by mid-late
afternoon, however the speed at which this warming proceeds may be
hampered some by diabatic effects. Ground temperatures from the
recent Arctic blasts remain quite cold adding to the ice accretion
potential. Further north the precipitation coverage on Sunday as
well as the actual threat remains much more in question and pops
are only in the chance range. The elevated warm layer further
north is much weaker as well, allowing for a greater threat of
sleet should precipitation occur. Some of the guidance actually
suggests a narrow west-east warm advection band could quickly lift
northward across the northern half of the CWA but confidence at
this point is low.
The forecast for Sunday night is hardly clear cut. I think the main
thrust of warm advection precipitation will have exited the CWA to
the east or be close to exiting at 00Z Monday. However weak warm
advection will persist in the evening and a weak trailing vort max
will track across the area. We could see a band of light snow across
northern MO into central IL in association with ascent with the vort
max and mid level convergence/frontogenesis, while further south the
warm advection may contribute to very light freezing rain or freezing
drizzle.
Cumulatively this looks like a light event, with ice amounts of a
tenth of an inch or less in the most threatened region of southeast
and east central MO into southern IL. A winter weather advisory
has been hoisted in this area with the main impact being on travel
from ice accumulation on untreated roadways.
Clouds and cold advection dominate on Monday with a chance of snow
in the morning. The clouds should slowly clear north-south during
the day. Arctic high pressure but not as formidable as recent
systems will dominate the region Tuesday into Wednesday. A
progressive upper trof will move through the lower/mid MS Valley
late Wednesday with any precipitation threat looking to be to the
south of us at this time. In the wake of this trof the flow aloft
flattens and heights rise, leading to moderating temperatures the
later half of the week and into next Saturday.
Glass
&&
.AVIATION: (For the 00z TAFs through 00z Sunday Evening)
Issued at 608 PM CST Sat Jan 10 2015
VFR fcst thru noon on Sunday as mid/high lvl moisture increases
tonight and tomorrow mrng. Precip chances increase drng the late
mrng and them ramp up substantially drng the aftn. model soundings
indicate that sfc temps will initially be below frzng will temps
aloft will be above frzng leading to mixed precip. Mdls are
indicating a narrow band of precip that may lift north Sunday mrng
but not sure it the column will be saturated enuf for any of that
to reach the ground. If it does, would likely be sleet but
confidence in this occurring is low so have not included it attm.
Larger area of precip should spread NE from late mrng thru the
aftn. This should primarily be -FZRA but can`t rule out some sleet
at the onset. Temps will be marginal drng the aftn with highs near
frzng. Temps are expected to drop a few degrees overnight
increasing the chance for the precip to be in the form of -FZRA.
The initial surge of precip drng the aftn and early evng is
expected to remain SE of KCOU and KUIN...therefore only have
prob30s to account for a possible mix drng the late aftn. light
precip is expected to continue beyond the end of the fcst prd
across the STL metro sites. The chance for precip also increases
across cntrl and NE MO and w cntrl IL overnight as well.
Specifics for KSTL:
VFR conditions thru 18Z with conditions deteriorating drng the aftn.
Precip is fcst to move into the terminal drng the aftn. Precip
type drng the aftn will be tricky with highs near 32. Sleet could
mix in at the onset of precip as well. Light precip should continue
overnight but temps are expected to drop a couple degrees allowing
-FZRA/FRDZ to be the main precip type overnight. CIGs should drop
thru the aftn into MVFR category with IFR CIGs and potentially IFR
VSBYs dvlpng overnight.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER WEATHER ADVISORY from 8 AM Sunday to 6 AM CST Monday FOR
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Lincoln MO-Madison MO-Osage MO-Reynolds MO-St. Charles MO-
St. Francois MO-St. Louis City MO-St. Louis MO-Ste.
Genevieve MO-Warren MO-Washington MO.
IL...WINTER WEATHER ADVISORY from 8 AM Sunday to 6 AM CST Monday FOR
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey
IL-Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
Randolph IL-St. Clair IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
242 PM MST FRI JAN 9 2015
.SHORT TERM...VALID FOR SAT AND SUN...
GENERALLY ANTI-CYCLONIC FLOW OVER THE FORECAST AREA AS A HIGH
PRESSURE RIDGE AXIS INFLUENCES OUR WEATHER. DEEP COLD AIR
GRADUALLY SLIDING TO THE EAST AS WARM AIR FILLS IN TO THE WEST.
THIS WEAK WARM FRONT WILL MOVE ACROSS THE CENTRAL ZONES THIS
EVENING. HRRR CROSS SECTIONS SHOW WARM AIR DEEPENING OVER
BILLINGS. SO I ANTICIPATE A RISE IN TEMPERATURES FROM AT LEAST
BILLINGS WESTWARD. THERE IS SOME DOUBT IF IT CAN PUSH ALL THE WAY
TO THE DAKOTA BORDER. AS FOR WIND CHILLS OVERNIGHT...THEY DO NOT
LOOK NEARLY AS BAD AS LAST NIGHT WITH 5 TO 15 BELOW TYPICAL AND
WINDS MARGINAL FOR MEETING CRITERIA. THEREFORE...WE WILL NOT BE
ISSUING ANY HIGHLIGHTS FOR WIND CHILLS AT THIS TIME.
SATURDAY IS QUIET OVERALL...BUT WE DO HAVE SOME WEAK CHANNEL-WISE
VORTICITY TRACKING ACROSS NE MONTANA. THERE IS LIMITED MOISTURE
AND FORCING SO I ONLY ADDED SOME FLURRIES TO THE MILES CITY/BAKER
AREA FOR THIS WEATHER FEATURE. WEST OF THIS AREA WE SHOULD SEE
SOME MODEST PREFRONTAL WARMING AHEAD OF THE TROUGH SWINGING SOUTH
FROM CANADA. ASSOCIATED SURFACE FRONT MOVES INTO REGION FROM THE
NORTH SATURDAY NIGHT. WINDS QUICKLY TURN EASTERLY AND UPSLOPE INTO
THE CRAZY MOUNTAINS AND BEARTOOTHS ON SUNDAY MORNING WITH DECENT
FRONTOGENESIS SETTING UP FROM THE CRAZIES/LITTLE BELTS
SOUTHEASTWARD INTO THE PRYORS/BIG HORNS. THIS APPEARS TO BE A
QUICK HIT AND OUT SYSTEM AS FORCING DIMINISHES QUICKLY BY SUNDAY
EVENING. TWO TO FOUR INCHES LOOK TYPICAL WEST OF A ROUNDUP TO
BILLINGS AND SHERIDAN LINE...WITH AROUND AN INCH OR LESS TO THE
EAST. NORTHEAST FACING FOOTHILLS COULD SEE THREE TO SIX INCHES AS
COULD SOME WEST FACING SLOPES EARLIER IN THE EVENT DUE TO
OROGRAPHICS. OTHERWISE...I DONT SEE ANY SIGNIFICANT FORCING
PROGGED FROM ANY OF THE MODELS FOR THE HIGH COUNTRY. MUCH OF THE
FORCING IS INDUCED BY THE 500MB HEIGHT FALLS PROCESS.
ALSO...THANKFULLY SREF PROGGS INDICATE RATHER SHALLOW DENDRITIC
GROWTH LAYERS AT THIS TIME...BUT WE WILL KEEP AN EYE ON ANY TRENDS
THAT DEVELOP. FROM ALL THE SNOW WE HAVE HAD...ANY SIGNIFICANT
ACCUMULATION WILL MAKE SIDE ROADS QUITE DIFFICULT TO DEAL WITH. BT
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
NO CHANGES TO THE GOING FORECAST THIS AFTERNOON. MODELS CONTINUE
TO ADVERTISE A WARMING TREND FROM MONDAY THROUGH NEXT WEEK.
LINGERING SNOW SHOWERS AND UPPER TROFINESS CONTINUE MONDAY INTO
TUESDAY WITH TEMPERATURES IN THE TEENS TO 20S MOST LOCATIONS.
UPPER LEVEL RIDGING FLOPS INTO THE AREA FROM THE WEST TUESDAY INTO
WEDNESDAY FOR DRY AND WARMER CONDITIONS. BY THURSDAY STRONG ZONAL
FLOW WILL PUSH INTO WEST CENTRAL CANADA WITH WEAK ANTICYCLONIC
FLOW OVER MONTANA. A DOWNSLOPE SURFACE PATTERN STRENGTHENS
THURSDAY INTO FRIDAY WHICH SHOULD DRIVE TEMPERATURES ABOVE AVERAGE
GOING INTO NEXT WEEKEND...AND MAY ALSO BRING SOME GUSTY WINDS TO
THE WESTERN FOOTHILLS AND ADJACENT PLAINS.
A DEVELOPING CONCERN WITH THE ANTICIPATED WARMER TEMPERATURES IS
SNOWMELT RUNOFF AND ICE JAM FORMATION. AS TEMPERATURES MOVE INTO
THE MID 40S WILL SEE THE WIDESPREAD SNOWPACK MELT. THE GROUND IS
FROZEN IN MOST AREAS THUS THIS WATER WILL RUNOFF AND POND AS
OPPOSED TO SOAKING INTO THE GROUND. CANT RULE OUT SOME FLOODING
CONCERNS ALONG STREAMS AND CREEKS AS WELL AS LOW LYING AREAS IF
THE CURRENT TEMPERATURE FORECASTS HOLD. ONCE THIS WATER GETS INTO
LARGER STREAMS AND RIVERS THE POTENTIAL FOR ICE JAMS AND LOCAL
FLOODING WILL INCREASE AS WELL. THE NEXT 3 TO 5 DAYS IS THE
OPPORTUNITY TO GET OUT AND ENSURE LIVESTOCK AND EQUIPMENT ARE AWAY
FROM FLOOD PRONE AREAS AND TO MAKE PREPARATIONS FOR THIS
POTENTIAL RUNOFF. IN URBAN AREAS SUCH AS BILLINGS...TRY TO CLEAR
STORM DRAINS THAT ARE PLUGGED WITH SNOW TO ALLOW RUNOFF TO DRAIN
EFFECTIVELY AND NOT BACK UP ACROSS ROADWAYS OR INTO BASEMENTS.
CHAMBERS
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL TONIGHT. WEST TO SOUTHWEST WINDS WILL
INCREASE THROUGH THIS EVENING. CAN`T RULE OUT A FEW AREAS OF
BLOWING SNOW FROM THE WESTERN FOOTHILLS NORTHEAST TOWARD BILLINGS
THIS EVENING AS WINDS INCREASE...BUT DO NOT EXPECT VISIBILITY TO
DROP BELOW LOCALIZED MVFR CRITERIA WITH THIS ACTIVITY. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 017/027 015/020 007/021 013/029 017/035 023/040 028/044
00/E 47/S 32/J 21/B 00/U 00/N 11/B
LVM 023/037 024/031 012/035 020/036 019/039 024/043 027/046
01/N 37/S 42/J 21/B 00/U 00/N 11/N
HDN 007/025 010/021 003/021 007/029 013/034 015/040 019/041
00/E 26/S 42/J 20/B 00/B 00/U 11/B
MLS 905/016 004/014 903/016 005/024 011/033 017/035 021/040
01/M 23/S 11/B 11/B 00/B 00/U 11/U
4BQ 004/024 008/019 003/022 009/028 012/035 016/038 020/041
00/E 04/S 21/B 11/B 00/B 00/U 00/B
BHK 905/015 002/013 909/015 005/023 010/032 016/035 021/040
02/S 23/S 10/B 00/B 00/B 00/U 11/B
SHR 012/031 014/025 006/026 011/031 013/036 017/041 022/043
00/B 15/S 52/J 21/B 00/U 00/U 00/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1131 PM CST THU JAN 8 2015
.SYNOPSIS...
ISSUED AT 352 PM CST THU JAN 8 2015
UA ANALYSIS THIS MORNING HAS A DEEP AREA OF LOW PRESSURE
OVER NRN QUEBEC WITH A LONGWAVE TROUGH EXTENDING SWD THROUGH THE
EASTERN THREE QUARTERS OF THE CONUS...RIDGING WAS PRESENT UP THE WEST
COAST OF THE CONUS INTO ALASKA. A VERY ACTIVE H5 PATTERN CONTINUES
OVER THE CONUS THIS AM WITH STRONG HT FALLS NOTED ACROSS THE
NORTHERN PLAINS AND CANADIAN PRAIRIE WITH 100 TO 200 METER HT FALLS
NOTED FROM THE DAKOTAS NWD INTO MANITOBA AND SASKATCHEWAN. FURTHER
EAST...100 TO 150 METER HT RISES EXTENDED FROM THE OHIO VALLEY NWD
TO LAKE ERIE. AT THE SURFACE...A STRONG CLIPPER SYSTEM IS CURRENTLY
LIFTING SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY TDY. A
PREFRONTAL TROUGH HAS SLID THROUGH THE ENTIRE FORECAST AREA AS OF
MID MORNING WITH A SECONDARY ARCTIC FRONT POSITIONED ACROSS THE
NORTHERN TIER OF COUNTIES IN THE FORECAST AREA AS OF NOONTIME. THIS
FEATURE HAS MADE IT INTO THE SANDHILLS AND WAS APPROACHING THE
INTERSTATE 80 CORRIDOR AS OF 3 PM CST. TEMPERATURES IN THE NORTHERN
CWA PEAKED LATE THIS MORNING AND CONTINUE TO DROP THIS AFTERNOON. ACROSS
THE CENTRAL AND SRN CWA...TEMPS HAVE FLAT LINED DURING THE NOONTIME
HOURS AND HAVE BEGUN TO FALL MID AFTERNOON. AS OF 3 PM
CST...TEMPERATURES RANGED FROM 19 AT VALENTINE...TO 44 AT
IMPERIAL.
&&
.UPDATE...
ISSUED AT 843 PM CST THU JAN 8 2015
WINDS HAVE SUBSIDED ACROSS SHERIDAN AND WESTERN CHERRY COUNTIES AS
INDICATED THE METAR AT PINE RIDGE AND 3 NEDOR OBSERVATIONS. THE
WINTER WEATHER ADVISORY IS CANCELLED.
A MILD REWORK OF TEMPERATURES AND WINDS TONIGHT USING THE RAP AND
THE PREVIOUS FORECAST SUGGESTS GARDEN COUNTY WILL FALL TO -20 WIND
CHILL BY MORNING SO THIS COUNTY HAS BEEN ADDED TO THE WIND CHILL ADVISORY.
UPDATE ISSUED AT 716 PM CST THU JAN 8 2015
WINDS HAVE SUBSIDED ACROSS MOST OF THE WINTER WEATHER ADVISORY
AREA THIS EVENING. THE BLOWING SNOW ADVISORY CAN BE CANCELLED
EVERYWHERE EXCEPT SHERIDAN AND WRN CHERRY COUNTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 352 PM CST THU JAN 8 2015
ONGOING STRONG WINDS AND BLOWING SNOW ON TRACK ACROSS NORTHERN
NEBRASKA. TEMPERATURES DID WARM INTO THE LOWER 40S FARTHER SOUTH
JUST BEFORE THE ARCTIC COLD FRONT PASSED...AND THAT WAS JUST ENOUGH
TO MELT ENOUGH SNOW TO FORM A CRUST...AND BLOWING SNOW HAS NOT BEEN
AN ISSUE. WINDS WILL CONTINUE INTO THE EVENING HOURS IN A SLOWLY
DIMINISHING FASHION. SNOW WILL CONTINUE TO BLOW ACROSS NORTHERN
NEBRASKA INTO THIS EVENING...AND THEN BEGIN TO TAPER AS WINDS
DIMINISH. WINDS ARE CONVERGING IN A ZONE AROUND THE BLACK HILLS
ACROSS NORTHWEST NEBRASKA...AND A BAND OF SNOW SHOWERS WILL LINGER
IN THIS CONVERGENCE AREA INTO EARLY THIS EVENING. THIS WILL FURTHER
REDUCE VISIBILITY WHEN COMBINED WITH BLOWING SNOW.
LATER TONIGHT WINDS AND CLOUD COVER DIMINISH...BUT ENOUGH WIND WILL
REMAIN TO CREATE DANGEROUSLY COLD WIND CHILLS AND HAVE POSTED A WIND
CHILL ADVISORY ACROSS NORTHERN NEBRASKA LATE TONIGHT INTO FRIDAY
MORNING.
MUCH MORE TRANQUIL FRIDAY. VERY DRY AIR ALOFT IN PLACE WILL ALLOW
FOR WELCOME SUNSHINE...BUT COLD CONDITIONS DESPITE THE SUN AS ARCTIC
AIR WILL HAVE A FIRM GRIP ON THE AREA DUE TO ANOTHER ARCTIC HIGH
PRESSURE SYSTEM SLIDING THROUGH. FORTUNATELY WINDS WILL BE LIGHT
WITH THE HIGH IN THE AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 352 PM CST THU JAN 8 2015
FRIDAY NIGHT THROUGH SUNDAY...IN THE MID RANGE
PERIODS...TEMPERATURES ARE THE MAIN FORECAST CONCERN. FOR FRIDAY
NIGHT...HIGH PRESSURE WILL TRACK FROM EASTERN KANSAS INTO THE
OZARKS. THE ARCTIC FRONT WHICH WAS ANCHORED ACROSS THE PANHANDLE ON
FRIDAY...WILL RETREAT EAST AS A WARM FRONT FRIDAY NIGHT WITH
SOUTHWESTERLY WINDS INCREASING WEST OF THIS FEATURE. OVERNIGHT LOWS
WILL BE EARLY IN THE WEST AND CENTRAL WITH RISING TEMPS OVERNIGHT AS
THE FRONT TRACKS EAST. IN ADDITION...CLOUD COVER IN ASSOCIATION WITH
THE FRONT WILL HOLD TEMPS UP AS WELL ESPECIALLY IN THE CENTRAL AND
WEST. THE INHERITED FCST HAD A GOOD HANDLE ON THIS WITH MINIMAL
CHANGES MADE TO THE MIN TEMP FCST AND T GRIDS. FOR SATURDAY...THE
WARM FRONT WILL PUSH FURTHER EAST WHILE WEST OF THE FRONT AN ARCTIC
COLD FRONT WILL APPROACH THE SD/NEBR BORDER BY 21Z SATURDAY. SOUTH
OF THE ARCTIC FRONT AND WEST OF THE WARM FRONT...TEMPERATURES WILL RISE
INTO THE 30S WITH SOME READINGS NEAR 40 IN THE FAR SOUTHWEST. IF WE
CAN MIX OUT SATURDAY...WE MAY SEE SOME 40S...HOWEVER...THE GFS AND
NAM SOLNS LIMIT MIXING SATURDAY...THUS A MORE CONSERVATIVE HIGH TEMP
FCST WAS UTILIZED. FOR SATURDAY NIGHT AND SUNDAY...A SECONDARY ARCTIC FRONT
WILL DROP SOUTH THROUGH THE FORECAST AREA LATE SATURDAY NIGHT INTO
SUNDAY MORNING. THE FROPA APPEARS TO BE A DRY ONE ATTM WITH LITTLE
OR NO UPPER LEVEL SUPPORT FOR PRECIPITATION NOTED. TEMPERATURES
SATURDAY NIGHT WILL RANGE FROM THE SINGLE DIGITS ACROSS FAR NRN
NEBRASKA TO THE LOWER TEENS IN THE CENTRAL AND SOUTHWEST. FOR
SUNDAY...HIGHS WILL RANGE FROM AROUND 20 IN THE FAR NORTHEAST...TO
THE LOWER 30S IN THE SOUTHWEST.
SUNDAY NIGHT THROUGH THURSDAY...A REINFORCING SHOT OF ARCTIC AIR
WILL PUSH INTO THE FORECAST AREA SUNDAY NIGHT. AS HIGH PRESSURE
MOVES INTO NORTH DAKOTA...EASTERLY WINDS WILL DEVELOP TO THE SOUTH
OF THIS FEATURE OVER WESTERN NEBRASKA. THIS WILL FAVOR INCREASED
PRECIPITATION CHANCES ALONG THE FRONT RANGES AND WESTERN NEBRASKA AS
MID LEVEL FORCING DROPS SOUTH FROM MONTANA INTO WYOMING AND NERN
COLORADO. DECIDED TO INSERT A LOW POP CHANCE IN THE WEST FOR SUNDAY
NIGHT ALONG THE SECOND ARCTIC FROPA...DUE TO EASTERLY UPSLOPE AND
MID LEVEL FORCING...WHICH IS PRESENT IN THE WESTERN CWA. FOR MONDAY
INTO TUESDAY...HIGH PRESSURE WILL DROP SOUTH FROM NORTH DAKOTA INTO
THE MID MISSISSIPPI VALLEY. EASTERLY WINDS MONDAY...AND CLOUD COVER
WILL HOLD TEMPS IN THE TEENS. ON TUESDAY...SRLY WINDS WILL RETURN TO
THE AREA...HOWEVER...ARCTIC AIR WILL REMAIN ENTRENCHED ACROSS THE
FORECAST AREA...WITH ONLY A SLIGHT UPWARD TREND IN TEMPS FROM
MONDAYS. BY WEDNESDAY...A WEAK CLIPPER SYSTEM WILL TRACK FROM
NORTHERN SASKATCHEWAN INTO WESTERN ONTARIO. WESTERLY WINDS WILL
DEVELOP...FORCING THE ARCTIC AIR EAST WITH TEMPS REBOUNDING BACK
INTO THE 30S. WESTERLY WINDS WILL CONTINUE INTO THURSDAY WITH HIGHS
APPROACHING THE LOWER 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1131 PM CST THU JAN 8 2015
THE MVFR CIGS AT KVTN ARE NOT VISIBLE ON THE SATELLITE SO THEY
MAY DEPART AT ANYTIME. OTHERWISE...SNOW AND LOCAL MVFR CIGS ACROSS
SWRN NEB SHOULD DEPART SOUTH BY 09Z. VFR IS EXPECTED THEREAFTER
ALL AREAS THROUGH FRIDAY AFTN.
THE MODELS SHOW MVFR CIGS RETURN NORTH OR EAST FRIDAY EVENING. THE
NAM LIFTS THIS CIGS NORTH THROUGH THE PANHANDLE AND THEN EAST TO
NEAR HIGHWAY 83 BY 06Z FRIDAY EVENING WHICH SEEMS TO BE THE BEST
SOLN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 AM CST /2 AM MST/ TO 10 AM CST /9 AM
MST/ FRIDAY FOR NEZ004>010-022>024-094.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...TAYLOR
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
114 PM EST FRI JAN 9 2015
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW SHOWERS TO THE REGION TODAY...WITH
SOME LAKE EFFECT SNOW TODAY INTO SATURDAY MORNING ACROSS THE
SOUTHERN SAINT LAWRENCE VALLEY AND THE WESTERN ADIRONDACKS. OTHERWISE
SEASONABLY COLD WEATHER IS EXPECTED INTO EARLY NEXT WEEK WITH
PERHAPS A FEW LIGHT FLURRIES OR SNOW SHOWERS FROM TIME TO
TIME...ESPECIALLY ACROSS THE HIGHER TERRAIN.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 100 PM EST FRIDAY... THE LAKE EFFECT BAND HAS COMBINED AHEAD
OF THE COLD FRONT TO PRODUCE A NARROW LINE OF SNOW SQUALLS OF
WHITE OUT CONDITIONS ORIENTED SOUTHWEST TO NORTHEAST ALONG THE
CHAMPLAIN VALLEY. THE SQUALLS ARE MOVING QUITE QUICKLY AND ONLY
PERSISTING FOR ABOUT 20-30 MINUTES BEFORE CLEARING. TRIED TO
FOCUS A BIT ON TIMING IN THE GRIDS AND SO I USED SOME OF THE BTV
WRF WITH A BLEND OF THE RUC REFLECTIVITY TO DERIVE THE POP GRIDS
OVER THE NEXT 3 TO 4 HOURS. ADDITIONAL CHANGES WERE TO ADD CURRENT
OBS FOR WINDS/TEMPS/DEW POINTS.
PREVIOUS DISCUSSION...COMPOSITE RADAR
SHOWS THE LAKE EFFECT SNOW BAND SLOWLY SHIFTING SOUTH AND EAST
OVER SOUTHERN ST LAWRENCE COUNTY. AS SUCH I INCREASED POPS OVER
THE SOUTHERN PORTION OF THE COUNTY. THE 12Z SUITE OF HI RES
WINDOWS SEEMS TO INDICATE THAT THE BAND WILL LINGER AND MAKE IT
ALL THE WAY ACROSS THE ADIRONDACKS INTO THE CHAMPLAIN VALLEY.
OTHER THAN THAT THE ONLY ADDITIONAL UPDATE WAS TO FRESHEN UP THE
TEMPS AND DEW POINTS AS WE ARE ALREADY WARMING INTO THE MID TO
UPPER TEENS ACROSS THE AREA. EXPECT TEMPS TO CONTINUE WARMING TO
THE UPPER TEENS TO LOW 20S ACROSS THE AREA WHICH WILL FEEL QUITE
PLEASANT COMPARED TO THE PREVIOUS COUPLE OF DAYS.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH SUNDAY/...
AS OF 425 AM EST FRIDAY...LAKE EFFECT SNOW BAND WILL CONTINUE
TONIGHT INTO EARLY SATURDAY MORNING BEFORE SHIFTING SOUTH OF THE
REGION ON SATURDAY. CLOUD COVER AND SOUTHWEST WINDS WILL HELP TO
KEEP TEMPERATURES UP TONIGHT...SO HAVE GONE SEVERAL DEGREES WARMER
THAN MOS GUIDANCE FOR MIN TEMPERATURES TONIGHT. STILL EXPECTING
SOME LIGHT SNOW SHOWER ACTIVITY TO LINGER ACROSS NORTHERN NEW YORK
AND VERMONT TONIGHT...OUTSIDE OF THE LAKE EFFECT SNOW BAND AREA.
MAINLY CLOUDY SKIES WILL LINGER INTO SATURDAY WITH JUST A SLIGHT
CHANCE FOR SOME SNOW SHOWERS OUTSIDE OF THE LAKE EFFECT SNOW BAND
AREA. MIN TEMPERATURES SATURDAY NIGHT LOOK TOO COLD GIVEN CLOUD
COVER AND SOUTHWEST WINDS ACROSS THE REGION...SO AGAIN HAVE GONE
SEVERAL DEGREES WARMER THAN MOS GUIDANCE FOR MIN TEMPERATURES
SATURDAY NIGHT. EXPECTING MOST OF THE REGION WILL BE DRY ON SUNDAY
EXCEPT FOR A SLIGHT CHANCE OF SNOW SHOWERS OVER THE ADIRONDACKS
AND SAINT LAWRENCE VALLEY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 330 AM EST FRIDAY...LONG TERM FCST WL CONT TO FEATURE
MID/UPPER LVL TROF ACRS THE NE CONUS WITH OUR CWA STILL BEING
IMPACTED BY THE NORTHERN STREAM. WL MENTION HIGH CHC POPS ON
MONDAY AS NORTHERN STREAM S/W ENERGY AND SOME ENHANCED 850 TO
500MB RH IMPACTS OUR CWA FROM SW TO NE. THIS INCREASE
RH...COMBINED WITH FAVORABLE SOUTHWEST WL RESULT IN A
LIGHT/WIDESPREAD SNOWFALL ACRS OUR CWA. THE LACK OF DEEP MOISTURE WL
KEEP SNOW AMOUNTS BTWN A DUSTING TO SEVERAL INCHES MTNS...WITH
THE TYPICAL SHADOWING HERE IN THE CPV. ON MONDAY NIGHT THRU WEDS
STRONG SFC HIGH PRES BUILDS INTO OUR REGION. SOUNDINGS SHOW DEEP
DRY LAYER OVERHEAD...COMBINED WITH LIGHT TRRN DRIVEN WINDS...WL
RESULT IN SOME CHILLY OVERNIGHT LOWS TUES AND WEDS MORNINGS.
EXPECT A LARGE VARIATION IN TEMPS BASED ON ELEVATION...WITH
COLDEST VALUES BTWN -10F AND -20F IN THE PROTECTED SNOW COVERED
MTN VALLEYS...WHILE MIDSLOPE AREAS STAY IN THE SINGLE DIGITS ABOVE
ZERO. DAYTIME HIGHS WL WARM INTO THE TEENS TO MID 20S...SUPPORTED
BY PROGGED 85H TEMPS BTWN -9C AND -13C. GIVEN LIGHT WINDS AND SOME
SNOW PACK...STRONG TEMP INVERSION MAY DEVELOP AND LIMIT SFC
HEATING IN THE DEEPER VALLEYS...ESPECIALLY ON WEDS...WITH WARMING
ALOFT.
WE ARE STILL WATCHING A SYSTEM OF INTEREST FOR LATE WEEK...AS 00Z
GUIDANCE HAS TRENDED BACK CLOSER TO THE COAST...ESPECIALLY THE
ECMWF. STILL NOT OVERLY IMPRESSED WITH THE MID/UPPER LVL PATTERN
FOR PRODUCING A SIGNIFICANT SNOWFALL ACRS OUR CWA...AS SYSTEM
REMAINS UNPHASED/PROGRESSIVE IN THE FAST FLW ALOFT. HOWEVER...THE
POTENTIAL FOR PHASING LOOKS POSSIBLE...GIVEN THE POSITION OF
SOUTHERN STREAM S/W ENERGY...IN RELATIONSHIP TO THE NORTHERN
STREAM TROF ACRS THE GREAT LAKES AT 00Z FRIDAY AND DEVELOPING
UPSTREAM RIDGE OVER THE NORTH ATLANTIC. WL MENTION CHC POPS
ATTM...WITH HIGHEST VALUES ACRS CENTRAL/SOUTHERN VT. TEMPS WL
REBOUND TO NEAR NORMAL VALUES...WITH HIGHS IN THE 20S AND LOWS
SINGLE DIGITS TO MID TEENS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 12Z SATURDAY...LINE OF SNOW SQUALL ACTIVITY IS ASSOCIATED
WITH A 20-30 MINUTE PERIOD OF 1/4SM VSBY...WHICH WILL AFFECT
PBG/BTV AROUND 18Z...AND EVENTUALLY MPV/RUT TAF SITES 20-22Z. WILL
ALSO SEE SOME WIND GUSTS TO 30 KTS WITH THE BRIEF HEAVY SNOW. VFR
CONDITIONS WILL REDEVELOP DEVELOP 20-22Z...EXCEPT LOCALLY MVFR AT
SLK/MPV WITH CONTINUED SNOW FLURRIES. AS LAKE EFFECT SNOW BAND
BECOMES REESTABLISHED OFF LAKE ONTARIO OVERNIGHT...WILL SEE SOME
ADDITIONAL IFR SNOW SHOWERS AT SLK 03-12Z SATURDAY WITH HIGHER
TERRAIN OBSCD. SURFACE WINDS GENERALLY SOUTH...BECOMING SW LATER
THIS AFTERNOON THROUGH THE REMAINDER OF THE TAF PERIOD.
OUTLOOK 12Z SATURDAY THROUGH WEDNESDAY...LAKE EFFECT SNOW SHOWERS
WILL PERIODICALLY AFFECT SLK AND MSS SATURDAY THROUGH ABOUT 06Z
SUNDAY. COULD SEE SOME BRIEF PERIODS OF IFR SNOWFALL DURING THIS
TIME FRAME. OTHERWISE...STRONG HIGH PRESSURE BUILDING EASTWARD
ACROSS THE ERN SEABOARD WILL MAINTAIN GENERALLY DRY CONDITIONS
THROUGH THE WEEKEND. A WEAK UPPER LEVEL DISTURBANCE MOVING IN FROM
THE GREAT LAKES WILL BRING THE POTENTIAL FOR ADDITIONAL SNOW
SHOWERS ON MONDAY...WITH BRIEF MVFR/IFR CONDITIONS. GENERALLY VFR
MONDAY NIGHT THROUGH THRU WEDNESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SATURDAY FOR NYZ030-
087.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST SATURDAY FOR NYZ029.
&&
$$
SYNOPSIS...WGH
NEAR TERM...DEAL
SHORT TERM...WGH
LONG TERM...TABER
AVIATION...BANACOS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1250 AM EST FRI JAN 9 2015
.SYNOPSIS...
A COLD FRONT WILL BRING WIDESPREAD LIGHT SNOW LATE TONIGHT INTO
FRIDAY MORNING. LAKE EFFECT WILL SET UP FRIDAY AFTERNOON TO SUNDAY
BUT MOST OF THE SNOW WILL BE NORTH OF THE NEW YORK THRUWAY.
MODERATING TEMPERATURES ARE EXPECTED SUNDAY WITH HIGHS REACHING
THE 20S.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATED AT 915 PM... FORECAST IS ON TRACK AS LIGHT SNOW IS
SPREADING EAST ACROSS EASTERN GREAT LAKES AND WILL REACH WESTERN
NEW YORK AND NORTHWEST PENNSYLVANIA BEFORE MIDNIGHT. EXPECT LIGHT
SNOW TO OVERSPREAD OUR FORECAST AREA BETWEEN 2 AM AND 5 AM. LATEST
HIGH RESOLUTION NAM/RAP FORECAST GUIDANCE IS INDICATING THAT A
MINIMA OF SNOWFALL MAY OCCUR OVER OUR WESTERN AND CENTRAL
COUNTIES. THIS WOULD BE DUE TO SOME DOWNSLOPING EFFECTS WITH 10
TO 25 KT SOUTHWESTERLY FLOW DOWNSLOPING EAST OF THE HIGHER
ALLEGHENY MOUNTAIN ELEVATIONS OF NORTHERN PA AND SOUTHWEST NY.
HOWEVER HIGHER AMOUNTS ARE STILL INDICATED FOR THE POCONOS AND
WESTERN CATSKILLS EAST OF I-81 WHICH ARE FARTHER REMOVED FROM THE
DOWNSLOPE AND WILL EXPERIENCE UPSLOPE FLOW LATER TONIGHT. THE
TERRAIN EFFECTS BEING INDICATED BY THE NAM AND RAP APPEAR TO BE
REASONABLE WITH FAIRLY STRONG WINDS ONGOING AND HAVE SHADED
FORECASTS SLIGHTLY IN THAT DIRECTION... REDUCING SNOWFALL AMOUNTS
SLIGHTLY OVER OUR CENTRAL AND SOUTHWESTERN COUNTIES... WHILE
KEEPING AMOUNTS THE SAME ACROSS THE NORTH AND EAST. PREVIOUS
DISCUSSION IS BELOW.
2 PM UPDATE...
LOW LEVEL SOUTHWEST FLOW CONTINUES KEEPING THE LAKE EFFECT NORTH
OF THE CWA. STILL COLD WITH WIND CHILLS AROUND ZERO. TEMPS IN
TEENS WITH WINDS AT 10 TO 15 MPH. TEMPERATURES TONIGHT STAY UP
WITH ANOTHER COLD FRONT MOVING THROUGH FRIDAY MORNING. GOOD LIFT
DUE TO JET DYNAMICS. A 150+KT UL JET PASSES TO OUR SOUTH. SNOW
ENDS ABRUPTLY WITH THE FROPA. SNOWFALL AMOUNTS INCH AT AVP TO 1 TO
2 TWIN TIERS TO 2 TO 4 INCHES SYR/RME. MORE NORTH WITH MORE
MOISTURE AND LIFT INTO TUG.
LIKE THE LAST FRONT THERE WILL BE A BREAK WHILE CAA OCCURS AND
THE UL TROF MOVES IN. THE AFTN WILL BE MOSTLY DRY WITH CLEARING
SKIES. LES WILL BE ACROSS THE NRN FINGER LAKES AND TUG. MIDDAY
HIGHS OF 20 TO 25.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
2 PM UPDATE...
THIS PERIOD DOMINATED BY A 250 TO 260 DEGREE FLOW. MODELS KEEP
SNOW BANDS NORTH OF THE CWA. SOME LIGHT SNOW SHOWERS AND FLURRIES
SHOULD MAKE IT INTO CENTRAL NY OFF OF LAKE ERIE. THE LAKE ONTARIO
BAND MAY DROP INTO NORTHERN ONEIDA BUT MOST MODELS KEEP IT NORTH.
KEPT THE POSSIBILITY IN THE HWO BUT CONFIDENCE NOT HIGH ENOUGH FOR
A FLAG. FOR TIMING IN NRN ONEIDA THE BEST CHANCE WILL BE SAT AFTN
AND NIGHT. AT THIS TIME A LARGE SURFACE HIGH MOVES EAST ACROSS THE
MID ATLANTIC STATES. THIS WILL KEEP NE PA SUNNY AND DRY.
WITH THE ARCTIC AIR LOW TEMPS FRI NGT AND SAT NGT IN THE SINGLE
DIGITS. HIGHS SAT IN THE TEENS AGAIN. SUNDAY SOME RECOVERY WITH
WAA...SO HIGHS IN 20S. SOME MODELS HAVE LIGHT SNOW OVER THE AREA
SUNDAY BUT LEFT CWA DRY. FLURRIES POSSIBLE NRN ONEIDA CONTINUES.
AIRMASS TOO DRY AND WITH SW FLOW NO LAKE MOISTURE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
2 PM UPDATE...
SOUTHERN STREAM MOISTURE WILL INTERACT WITH ANOTHER ARCTIC FRONT
MOVING THRU THE GREAT LAKES SUNDAY NIGHT AND BRING MORE SNOW
SHOWERS TO OUR AREA SUNDAY NGT INTO MONDAY. THERE WILL BE SOME
RESIDUAL LAKE EFFECT SNOWS INTO MON NGT-TUESDAY BEFORE ANOTHER
LARGE HIGH PRESSURE SYSTEM COVERS THE NORTHEAST U.S INTO WED NGT/THU.
THERE IS A CHANCE OF A SRN BRANCH SYSTEM TUE-THU AND WILL KEEP
POPS IN NE PA AND SERN NY AS PER WPC GUIDC AND COLLABORATION WITH
SURROUNDING OFFICES. IN C NY THE HIGH PRESSURE WILL KEEP THINGS
DRY AND CHILLY IN THIS PERIOD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT WILL SWEEP ACROSS THE REGION EARLY THIS MORNING AND
BRING THE AREA A PERIOD OF LIGHT SNOW. IN GENERAL IFR CONDITIONS
DUE PRIMARILY TO VSBYS WILL IMPACT ALL TERMINALS AT APPROX 08Z-
12Z. AT KITH/KBGM, CONDITIONS WILL OCCASIONALLY FALL BELOW AIRPORT
MINS BETWEEN 08Z-11Z. ONCE THE STEADY SNOW PASSES MVFR CIGS WILL
LINGER AT MOST SITES UNTIL MID/LATE MORNING THEN IMPROVEMENT TO
VFR. CONDITIONS WILL REMAIN PRIMARILY VFR OVERNIGHT AS LAKE EFFECT
SNOWS SHOULD REMAIN NORTH OF BOTH THE KSYR/KRME TERMINALS.
S/SW WINDS AT 10 KNOTS GUSTING TO 20 KNOTS SHIFTING TO THE
SOUTHWEST EARLY THIS MORNING AND INCREASING TO 10-15 KNOTS WITH
GUSTS AT 25-30 KNOTS. WINDS DIMINISHING THIS EVENING TO 8-12 KNOTS.
OUTLOOK...
SAT - SUN...PRIMARILY VFR.
MON...RESTRICTIONS POSSIBLE IN -SN.
TUE...VFR EXCEPT RESTRICTIONS POSSIBLE AT TIMES WITH LAKE EFFECT
-SHSN OVR NY TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...MSE/TAC
SHORT TERM...TAC
LONG TERM...DJN
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
259 PM EST FRI JAN 9 2015
.SYNOPSIS... A COLD FRONT MOVES THROUGH THE REGION THROUGH
TONIGHT...THEN HIGH PRESSURE BUILDS OVER THE REGION AND REMAINS AT
LEAST THROUGH THE DAY SUNDAY. UNSETTLED WEATHER RETURNS BY MONDAY
DUE TO UPPER-LEVEL DISTURBANCES...AND SURFACE LOW PRESSURE ALONG THE
COAST.
&&
.NEAR TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 245 PM FRIDAY...
CLEAR CONDITIONS HAD DEVELOPED OVER CENTRAL NORTH CAROLINA AHEAD OF
A MID-LEVEL SHORTWAVE MOVING THROUGH THE LOWER GREAT LAKES AND
SOUTHWEST THROUGH THE APPALACHIANS. A MORE NOTICEABLE 700MB
SHORTWAVE AS FORECAST BY THE SHORT-TERM GUIDANCE SHOULD MOVE THROUGH
CENTRAL NORTH CAROLINA OVERNIGHT...AS THE RIGHT ENTRANCE REGION OF A
130KT 300MB JET PASSES THROUGH THE AREA. MUCH OF THE AIR MASS WILL
BE DRY...WITH ESSENTIALLY ONLY MOISTURE AROUND 300MB AS BUFR
SOUNDINGS FROM BOTH THE NAM AND THE GFS SHOW DRY CONDITIONS THROUGH
A LARGE VOLUME AND K INDICES FALLING INTO THE DOUBLE DIGITS BELOW
ZERO. ALREADY UPSTREAM...IN THE SOUTHWEST FLOW ALOFT AS THE MID-
LEVEL WAVE AND JET APPROACH...WATER VAPOR AND STANDARD IR SATELLITE
IMAGES SHOW STRANDS OF HIGH CLOUDS MOVING TOWARD CENTRAL NORTH
CAROLINA. GFS UPPER-LEVEL RELATIVE HUMIDITY...THE CANADIAN CLOUD
COVER MODEL...AND HRRR SHORT-TERM CLOUD COVER GUIDANCE ALL SUGGEST
AT LEAST A PERIOD OF PARTLY CLOUDY CONDITIONS DUE TO HIGH CLOUDS
DEVELOPING OVER MUCH OF CENTRAL NORTH CAROLINA...LEAST CONFIDENT AND
FOR THE SHORTEST TIME TOWARD THE TRIAD AND MORE CONFIDENT AND FOR A
LONGER AMOUNT OF TIME AS ONE GOES SOUTHEAST. LATE TONIGHT...EVEN THE
MOISTURE ALOFT DRIES WELL BEHIND THE COLD FRONT MOVING OVER THE
MOUNTAINS...AND AS THE JET ALOFT CONTINUES TO MOVE EAST AND WEAKEN.
LEANED TOWARD THE COOLER MOS GUIDANCE NORTHWEST...AND THE WARMER MOS
GUIDANCE TOWARD KFAY...FOR LOWS OF 15 TO 20 WEST OF INTERSTATE
95...AND IN THE UPPER TEENS TO LOWER 20S RIGHT ALONG AND EAST OF
INTERSTATE 95. THERE SHOULD BE SOME MIXING OVERNIGHT AS 850MB AND
925MB WINDS INCREASE TO 25 TO 35KT AND KEEP SOME WIND AT THE
SURFACE...ENOUGH THAT MUCH OF CENTRAL NORTH CAROLINA SHOULD
EXPERIENCE MINIMUM WIND CHILLS IN THE SINGLE DIGITS ABOVE ZERO.
PARTICULARLY TOWARD KFAY AND KCTZ...THOSE MINIMUM WIND CHILLS MAY
ONLY GET AS LOW AS AROUND OR JUST ABOVE 10F DEPENDING ON THE TIMING
OF THE EXIT OF ANY HIGH CLOUDS LATE TONIGHT.
SATURDAY INTO SATURDAY NIGHT...THE SURFACE GRADIENT IS TIGHT
SATURDAY MORNING WITH THE 850MB AND 925MB WINDS OF 25 TO 35KT...BUT
SURFACE HIGH PRESSURE BUILDS IN QUICKLY SUCH THAT THE GFS REALLY
DIMINISHES THE 925MB WINDS BETWEEN 12Z AND 18Z SATURDAY...LEAVING
THEM 5 TO 10KT FOR SATURDAY NIGHT. WITH MIXING SATURDAY GFS AND NAM
BUFR SOUNDINGS SUGGEST FOR MOST OF CENTRAL NORTH CAROLINA SOME GUSTS
IN THE TEENS KNOTS WHICH SHOULD AGAIN DIMINISH INTO THE AFTERNOON.
UNDER 850MB SUBSIDENCE AND THETA-E TROUGHING...AND K INDICES WELL
INTO THE NEGATIVE DOUBLE FIGURES...THE AIR MASS IS DRY...AND DEW
POINTS FOR MOST IF NOT ALL OF CENTRAL NORTH CAROLINA SHOULD GO
NEGATIVE SATURDAY. UNDER CONSIDERABLE SUNSHINE THAT IS EXPECTED FOR
SATURDAY...HIGHS SHOULD RISE INTO THE 30S...JUST ABOVE FREEZING IN
MANY AREAS NORTH OF U.S. 64 AND INTO THE UPPER 30S OVER MUCH OF THE
SANDHILLS AND SOUTHERN COASTAL PLAIN. ASIDE FROM SOME BRIEF CIRRUS
ESPECIALLY IN THE EVENING SATURDAY...THE SURFACE HIGH PRESSURE RIDGE
AXIS OVERHEAD SHOULD ALLOW FOR VERY LIGHT OR CALM WINDS OVERNIGHT.
1000-850MB THICKNESSES RISE AS THE FLOW ALOFT BACKS SOUTHWEST...BUT
MOS GUIDANCE IS CHILLY UNDER THE RIDGE AND LIGHT WINDS AND
CONSISTENT BETWEEN THE MAV AND MET...AND IS CONSIDERABLE REASONABLE.
OVERNIGHT LOWS SATURDAY NIGHT IN THE TEENS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 255 PM FRIDAY...
SURFACE HIGH PRESSURE OVER THE MID-ATLANTIC WILL KEEP CENTRAL NC DRY
FOR MOST OF THE DAY ON SUNDAY BUT LOW LEVEL MOISTURE WILL INCREASE
FROM THE SOUTH DUE TO ISENTROPIC LIFT WILL CLOUD THINGS UP BY SUNDAY
AFTERNOON AND INCREASING TO OVERCAST BY EVENING. MODELS CURRENTLY
PROGGING PRECIPITATION ASSOCIATED WITH A DEVELOPING COASTAL LOW TO
ARRIVE IN OUR WESTERN COUNTIES SOMEWHERE BETWEEN 0-6Z MONDAY. MODELS
HAVE TRENDED A BIT WARMER DURING THIS TIME FRAME AND WILL KEEP LOWS
ABOVE FREEZING AND PRECIPIATION ALL LIQUID AT THIS TIME. MODELS ARE
ALSO TRENDING WETTER AND WILL INCREASE QPF AMOUNTS WITH THIS
FORECAST PACKAGE TO NEAR HALF OF AN INCH ALTHOUGH SOME MODELS
INDICATING BETWEEN A HALF OF AN INCH AND AN INCH OF RAIN IN SOME
SPOTS. TIMING DETAILS FOR THE HEAVIEST RAIN ARE STILL LOW CONFIDENCE
WITH THE GFS BRINING PRECIP IN EARLIER MONDAY MORNING AND THE ECWMF
HOLDING OFF UNTIL LATER IN THE AFTERNOON AND EVENING ON MONDAY.
TEMPERATURES IN THE LOW TO UPPER 40S NW TO SE SUNDAY AND MODERATING
TO THE MID 40S TO LOW 50S ON MONDAY. LOWS MONDAY NIGHT WILL BE A
QUESTION OF WHERE THE PRECIPITATION IS AT THAT TIME. RIGHT NOW IT
LOOKS LIKE IT WILL EITHER BE WETTER AND ABOVE FREEZING OR DRIER AND
BELOW FREEZING DEPENDING ON THE SOLUTION. STAY TUNED FOR EVOLVING
DETAILS ON ANY P-TYPE OR BLACK ICE ISSUES FOR TUESDAY MORNING.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 PM FRIDAY...
THE LONG TERM WILL REMAIN GENERALLY UNSETTLED FROM TUESDAY THROUGH
THURSDAY WITH A COUPLE OF CHANCES FOR NON-LIQUID P-TYPES.
TUESDAY WILL FEATURE THE EXITING COAST LOW TO THE NORTHEAST AND
POTENTIALLY A RELATIVE LULL IN PRECIPITATION. MODEL DIFFERENCES IN
TIMING AND THE NORTHWARD EXTEND OF THE PRECIPITATION SHIELD KEEP
CONFIDENCE LOW TO MEDIUM. CLOSER TOWARDS EVENING...A WEDGE FRONT
BUILDS SOUTHWARD OUT OF A 1035 MB HIGH CENTERED OVER EASTERN PA.
THIS WILL BEGIN TO INCREASE THE CHANCES FOR OVERRUNNING PRECIPIATION
AS TEMPERATURES DROP TUESDAY NIGHT. THE CURRENT RUN OF THE GFS HAS
WET BULB TEMPERATURES DROPPING BELOW FREEZING FOR MUCH OF THE CWA BY
00Z AND INTO THE LOW TO MID 20S EVERYWHERE BY 12Z WEDNESDAY. THE
SURFACE LOWS RIGHT AROUND FREEZING OR SLIGHTLY BELOW...THE CHANCES
FOR SOME FREEZING RAIN WEDNESDAY MORNING LOOK GOOD...IF WE CAN GET
THE PRECIPITATION THAT IS. THE BEST CHANCES FOR PRECIPITATION WILL
BE IN THE SOUTHEAST...BUT TEMPERATURES THERE ARE MARGINAL. THEREFORE
WILL HAVE CHANCES FOR FREEZING RAIN IN THE NORTHWEST PIEDMONT WITH
CHANCES OF RAIN OR FREEZING RAIN ELSEWHERE THROUGH ABOUT 15Z ON
WEDNESDAY. QPF LOOKS TO BE FAIRLY LIGHT WITH MOST PLACES SEEING
PROBABLY LESS THAN A TENTH OF AN INCH OF LIQUID.
A LARGE TEMPERATURE GRADIENT IS EXPECTED FOR WEDNESDAY AS THE WEDGE
SHARPENS UP AND THE TRIAD STRUGGLES TO GET OUT OF THE 30S. MEANWHILE
ALONG I-95 TEMP WILL RISE INTO THE MID TO UPPER 40S. A STRONGER
COASTAL LOW WILL PASS TO THE SOUTHEAST OFFSHORE ON WEDNESDAY NIGHT
INTO THURSDAY MORNING. THIS WILL POTENTIALLY GIVE US ANOTHER SHOT
FOR SOME FROZEN PRECIPITATION BUT THE SYSTEM PASSING SO FAR OFFSHORE
GIVE LOW CONFIDENCE TO WHETHER OR NOT PRECIPIATION WILL MOVE THIS
FAR NORTHWARD. WILL KEEP AS RAIN FOR NOW BUT CANT RULE OUT SOME
FROZEN P-TYPES IN THE NORTHWEST PIEDMONT THURSDAY MORNING. LOWS
AROUND FREEZING THURSDAY MORNING WILL RISE TO THE MID 40S TO NEAR 50
IN THE SOUTH BY THURSDAY AFTERNOON. RAIN CHANCES WILL END THURSDAY
EVENING AND SKIES WILL FINALLY BEGIN TO CLEAR OUT FOR FRIDAY AS A
RIDGE BUILDS IN FROM THE WEST. HIGHS FRIDAY IN THE MID TO UPPER 40S.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1250 PM FRIDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 18Z VALID TAF PERIOD AND
BEYOND...AT LEAST INTO THE DAY SUNDAY. SUB-VFR CONDITIONS IN LOW
CLOUDS AND AREAS OF PRECIPITATION ARE LIKELY BY LATE SUNDAY NIGHT
AND CONTINUING INTO MONDAY AS A LOW PRESSURE SYSTEM MOVES NORTH 0
ALONG THE CAROLINA COAST. A BRIEF RETURN TO VFR CONDITIONS IS
POSSIBLE BY TUESDAY...THEN OVERNIGHT TUESDAY SUB-VFR CONDITIONS ONCE
AGAIN APPEAR POSSIBLE...MVFR THE LIKELY CATEGORY IF IT OCCURS...
WITH MORE AREAS OF PRECIPITATION. AVIATION INTERESTS SHOULD KEEP
ABREAST OF THE LATEST FORECASTS FOR PRECIPITATION NEAR AND NORTHWEST
OF THE TRIAD LATE SUNDAY NIGHT INTO EARLY MONDAY...AND ACROSS
CENTRAL NORTH CAROLINA ESPECIALLY TUESDAY NIGHT WITH REGARD TO
PRECIPITATION TYPE...TEMPERATURE...AND TIMING. CONDITIONS ARE
CURRENTLY EXPECTED TO RETURN TO VFR ON WEDNESDAY. THROUGH TONIGHT
INTO SATURDAY...WINDS WILL GRADUALLY VEER...BECOMING NORTHWEST
TONIGHT AND NORTH EARLY SATURDAY...WITH SOME GUSTINESS LIKELY INTO
THE TEENS KNOTS WITH MIXING SATURDAY MORNING BEFORE WINDS DIMINISH
DURING THE DAY AS HIGH PRESSURE BUILDS IN.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...ELLIS
LONG TERM...ELLIS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
245 PM EST FRI JAN 9 2015
.SYNOPSIS... A COLD FRONT MOVES THROUGH THE REGION THROUGH
TONIGHT...THEN HIGH PRESSURE BUILDS OVER THE REGION AND REMAINS AT
LEAST THROUGH THE DAY SUNDAY. UNSETTLED WEATHER RETURNS BY MONDAY
DUE TO UPPER-LEVEL DISTURBANCES...AND SURFACE LOW PRESSURE ALONG THE
COAST.
&&
.NEAR TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 245 PM FRIDAY...
CLEAR CONDITIONS HAD DEVELOPED OVER CENTRAL NORTH CAROLINA AHEAD OF
A MID-LEVEL SHORTWAVE MOVING THROUGH THE LOWER GREAT LAKES AND
SOUTHWEST THROUGH THE APPALACHIANS. A MORE NOTICEABLE 700MB
SHORTWAVE AS FORECAST BY THE SHORT-TERM GUIDANCE SHOULD MOVE THROUGH
CENTRAL NORTH CAROLINA OVERNIGHT...AS THE RIGHT ENTRANCE REGION OF A
130KT 300MB JET PASSES THROUGH THE AREA. MUCH OF THE AIR MASS WILL
BE DRY...WITH ESSENTIALLY ONLY MOISTURE AROUND 300MB AS BUFR
SOUNDINGS FROM BOTH THE NAM AND THE GFS SHOW DRY CONDITIONS THROUGH
A LARGE VOLUME AND K INDICES FALLING INTO THE DOUBLE DIGITS BELOW
ZERO. ALREADY UPSTREAM...IN THE SOUTHWEST FLOW ALOFT AS THE MID-
LEVEL WAVE AND JET APPROACH...WATER VAPOR AND STANDARD IR SATELLITE
IMAGES SHOW STRANDS OF HIGH CLOUDS MOVING TOWARD CENTRAL NORTH
CAROLINA. GFS UPPER-LEVEL RELATIVE HUMIDITY...THE CANADIAN CLOUD
COVER MODEL...AND HRRR SHORT-TERM CLOUD COVER GUIDANCE ALL SUGGEST
AT LEAST A PERIOD OF PARTLY CLOUDY CONDITIONS DUE TO HIGH CLOUDS
DEVELOPING OVER MUCH OF CENTRAL NORTH CAROLINA...LEAST CONFIDENT AND
FOR THE SHORTEST TIME TOWARD THE TRIAD AND MORE CONFIDENT AND FOR A
LONGER AMOUNT OF TIME AS ONE GOES SOUTHEAST. LATE TONIGHT...EVEN THE
MOISTURE ALOFT DRIES WELL BEHIND THE COLD FRONT MOVING OVER THE
MOUNTAINS...AND AS THE JET ALOFT CONTINUES TO MOVE EAST AND WEAKEN.
LEANED TOWARD THE COOLER MOS GUIDANCE NORTHWEST...AND THE WARMER MOS
GUIDANCE TOWARD KFAY...FOR LOWS OF 15 TO 20 WEST OF INTERSTATE
95...AND IN THE UPPER TEENS TO LOWER 20S RIGHT ALONG AND EAST OF
INTERSTATE 95. THERE SHOULD BE SOME MIXING OVERNIGHT AS 850MB AND
925MB WINDS INCREASE TO 25 TO 35KT AND KEEP SOME WIND AT THE
SURFACE...ENOUGH THAT MUCH OF CENTRAL NORTH CAROLINA SHOULD
EXPERIENCE MINIMUM WIND CHILLS IN THE SINGLE DIGITS ABOVE ZERO.
PARTICULARLY TOWARD KFAY AND KCTZ...THOSE MINIMUM WIND CHILLS MAY
ONLY GET AS LOW AS AROUND OR JUST ABOVE 10F DEPENDING ON THE TIMING
OF THE EXIT OF ANY HIGH CLOUDS LATE TONIGHT.
SATURDAY INTO SATURDAY NIGHT...THE SURFACE GRADIENT IS TIGHT
SATURDAY MORNING WITH THE 850MB AND 925MB WINDS OF 25 TO 35KT...BUT
SURFACE HIGH PRESSURE BUILDS IN QUICKLY SUCH THAT THE GFS REALLY
DIMINISHES THE 925MB WINDS BETWEEN 12Z AND 18Z SATURDAY...LEAVING
THEM 5 TO 10KT FOR SATURDAY NIGHT. WITH MIXING SATURDAY GFS AND NAM
BUFR SOUNDINGS SUGGEST FOR MOST OF CENTRAL NORTH CAROLINA SOME GUSTS
IN THE TEENS KNOTS WHICH SHOULD AGAIN DIMINISH INTO THE AFTERNOON.
UNDER 850MB SUBSIDENCE AND THETA-E TROUGHING...AND K INDICES WELL
INTO THE NEGATIVE DOUBLE FIGURES...THE AIR MASS IS DRY...AND DEW
POINTS FOR MOST IF NOT ALL OF CENTRAL NORTH CAROLINA SHOULD GO
NEGATIVE SATURDAY. UNDER CONSIDERABLE SUNSHINE THAT IS EXPECTED FOR
SATURDAY...HIGHS SHOULD RISE INTO THE 30S...JUST ABOVE FREEZING IN
MANY AREAS NORTH OF U.S. 64 AND INTO THE UPPER 30S OVER MUCH OF THE
SANDHILLS AND SOUTHERN COASTAL PLAIN. ASIDE FROM SOME BRIEF CIRRUS
ESPECIALLY IN THE EVENING SATURDAY...THE SURFACE HIGH PRESSURE RIDGE
AXIS OVERHEAD SHOULD ALLOW FOR VERY LIGHT OR CALM WINDS OVERNIGHT.
1000-850MB THICKNESSES RISE AS THE FLOW ALOFT BACKS SOUTHWEST...BUT
MOS GUIDANCE IS CHILLY UNDER THE RIDGE AND LIGHT WINDS AND
CONSISTENT BETWEEN THE MAV AND MET...AND IS CONSIDERABLE REASONABLE.
OVERNIGHT LOWS SATURDAY NIGHT IN THE TEENS.
&&
.SHORT TERM /SUNDAY/...
AS OF 245 AM FRIDAY...
CLOUDS THICKEN AND LOWER FROM THE SOUTHWEST ON SUNDAY. HIGHS ON
SUNDAY WILL MODERATE A BIT FROM SATURDAY AND RANGE IN THE LOWER TO
MID 40S. -BLAES
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...
AN UNSETTLED PATTERN WITH A GOOD DEAL OF UNCERTAINTY MAY LEAD TO A
CHANCE OF SOME WINTRY PRECIPITATION OVER OUR CLIMATOLOGICALLY
FAVORED LOCATIONS MID WEEK.
THE PATTERN ALOFT WILL COMPLETE ITS TRANSITION A SOUTHERN STREAM
DOMINANT...SOUTHWESTERLY FLOW EARLY IN THE LONG TERM AND CONTINUE
FOR MUCH OF THE PERIOD. THIS PATTERN TYPICALLY LEADS TO MORE
UNCERTAINTY THAN AVERAGE...OFTEN ALONG WITH UNSETTLED WEATHER AS LOW
AMPLITUDE WAVES MOVE QUICKLY IN THE FAST FLOW ALOFT. TIMING THESE
FEATURES AND RESOLVING DETAILS IS OFTEN PROBLEMATIC AS IS
IDENTIFYING POTENTIAL PHASING WITH THE NORTHERN STREAM.
WITH ALL OF THE CAVEATS OF OUT THE WAY...THE FIRST DISTURBANCE TO
AFFECT THE LONG TERM WILL ARRIVE LATE SUNDAY NIGHT AND CONTINUE INTO
MONDAY EVENING. STRENGTHENING ISENTROPIC LIFT EARLY MONDAY COMBINED
WITH A SHORT WAVE TROUGH LATE MONDAY SHOULD RESULT IN A COUPLE
BATCHES OF PRECIPITATION THAT SHOULD TAPER OFF MONDAY NIGHT. PARTIAL
THICKNESS VALUES FROM THE GFS/NAM/AND ALL SREF MEMBERS SUGGEST AN
ALL RAIN EVENT BUT SURFACE WET BULBS IN THE NORTHWEST PIEDMONT
SUGGEST A NARROW WINDOW OF FREEZING RAIN IS POSSIBLE AROUND ONSET
TIME. GIVEN THE LOCATION OF THE SURFACE HIGH AND THE THE TREND FOR
SLOWER PRECIP ARRIVAL...FAVOR AN ALL RAIN FORECAST FOR NOW BUT THIS
PART OF THE FORECAST WILL NEED TO BE MONITORED FOR THE POTENTIAL FOR
SOME FREEZING RAIN IN THE TRIAD AREA SUNDAY NIGHT AND VERY EARLY
MONDAY. LOWS SUNDAY NIGHT SHOULD RANGE IN THE LOWER TO MID 30S.
HIGHS WILL RANGE IN THE MID 40S IN THE NORTHWEST TO LOWER 50S IN THE
SOUTHEAST. LOWS MONDAY NIGHT WILL RANGE IN THE LOWER TO MID 30S
AGAIN.
UNCERTAINTY INCREASES A GREAT DEAL FOR TUESDAY THROUGH THURSDAY AS
MODEL GUIDANCE HAS TRENDED STRONGER WITH THE MIGRATING SURFACE HIGH
ACROSS THE GREAT LAKES AND NORTHEAST THAT RIDGES INTO THE PIEDMONT
OF VA AND THE CAROLINAS. THIS COLDER TREND AND STRONGER COLD AIR
DAMMING SIGNATURE LEADS TO A MORE SUPPRESSED PATTERN BUT ONE THAT
COULD SUPPORT SOME WINTRY PRECIPITATION...MAINLY ACROSS THE
CLIMATOLOGICALLY FAVORED LOCATIONS OF THE INTERIOR NORTHERN
PIEDMONT. WITH THE SOUTHERN SHIFT OF THE MAIN WEATHER FEATURES FOR
TUESDAY AND WEDNESDAY WE HAVE LOWERED POPS BELOW WPC GUIDANCE AND
SHIFTED THEM SOUTHWARD. THE TREND APPEARS TO BE FOR A LESS IMPACTFUL
SYSTEM. THE PRECIPITATION DURING THIS PERIOD WILL LARGELY RESULT
FROM SOME SHALLOW ISENTROPIC LIFT AND AN EJECTING SOUTHERN STREAM
SHORT WAVE TROUGH. LOW CHANCE POPS WILL BE INCLUDED FOR MOST OF THIS
PERIOD. WE HAVE INTRODUCED A SLIGHT CHANCE OF FREEZING RAIN ACROSS
THE NORTHWEST PIEDMONT FOR LATE TUESDAY NIGHT AND WEDNESDAY MORNING
WITH LOWS NEAR FREEZING...IF MORE WIDESPREAD PRECIPITATION
DEVELOPS...THESE TEMPS WILL BE TOO WARM AND THE WINTRY P-TYPE AREA
WOULD NEED TO BE EXPANDED. HIGHS BOTH DAYS WILL RANGE IN THE LOWER
40S NORTHWEST TO UPPER 40S SOUTHEAST.
AFTER A LULL LATE WEDNESDAY...BOTH THE GFS AND ECMWF INDICATE THE
POTENTIAL FOR A MORE ORGANIZED STORM SYSTEM ON THURSDAY AS SOME
NORTHERN AND SOUTHERN STREAM PHASING IS IMPLIED. THIS IS ALSO
SUPPORTED BY HALF OF THE GEFS ENSEMBLE MEMBERS AS WELL AS THE
PARALLEL GFS. THE SURFACE WAVE IS LIKELY TO BE WEAK AS IT MOVES
ACROSS THE MID ATLANTIC BEFORE STRENGTHENING OFFSHORE. A PERIOD OF
LIGHT PRECIPITATION IS POSSIBLE THURSDAY INTO THURSDAY NIGHT AND
FOR NOW IT APPEARS THE AIR MASS OVER CENTRAL NC WIL HAVE MODERATED
ENOUGH FOR AN ALL LIQUID EVENT WITH MORNING LOWS IN THE MID 30S TO
NEAR 40 AND AFTERNOON HIGHS IN THE 40S. -BLAES
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1250 PM FRIDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 18Z VALID TAF PERIOD AND
BEYOND...AT LEAST INTO THE DAY SUNDAY. SUB-VFR CONDITIONS IN LOW
CLOUDS AND AREAS OF PRECIPITATION ARE LIKELY BY LATE SUNDAY NIGHT
AND CONTINUING INTO MONDAY AS A LOW PRESSURE SYSTEM MOVES NORTH 0
ALONG THE CAROLINA COAST. A BRIEF RETURN TO VFR CONDITIONS IS
POSSIBLE BY TUESDAY...THEN OVERNIGHT TUESDAY SUB-VFR CONDITIONS ONCE
AGAIN APPEAR POSSIBLE...MVFR THE LIKELY CATEGORY IF IT OCCURS...
WITH MORE AREAS OF PRECIPITATION. AVIATION INTERESTS SHOULD KEEP
ABREAST OF THE LATEST FORECASTS FOR PRECIPITATION NEAR AND NORTHWEST
OF THE TRIAD LATE SUNDAY NIGHT INTO EARLY MONDAY...AND ACROSS
CENTRAL NORTH CAROLINA ESPECIALLY TUESDAY NIGHT WITH REGARD TO
PRECIPITATION TYPE...TEMPERATURE...AND TIMING. CONDITIONS ARE
CURRENTLY EXPECTED TO RETURN TO VFR ON WEDNESDAY. THROUGH TONIGHT
INTO SATURDAY...WINDS WILL GRADUALLY VEER...BECOMING NORTHWEST
TONIGHT AND NORTH EARLY SATURDAY...WITH SOME GUSTINESS LIKELY INTO
THE TEENS KNOTS WITH MIXING SATURDAY MORNING BEFORE WINDS DIMINISH
DURING THE DAY AS HIGH PRESSURE BUILDS IN.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...BLAES
LONG TERM...BLAES
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1251 PM EST FRI JAN 9 2015
.SYNOPSIS... A COLD FRONT MOVES THROUGH THE REGION THROUGH
TONIGHT...THEN HIGH PRESSURE BUILDS OVER THE REGION AND REMAINS AT
LEAST THROUGH THE DAY SUNDAY. UNSETTLED WEATHER RETURNS BY MONDAY
DUE TO UPPER-LEVEL DISTURBANCES...AND SURFACE LOW PRESSURE ALONG THE
COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1050 AM FRIDAY...
CLEARING HAS OCCURRED THROUGHOUT VIRTUALLY ALL OF CENTRAL NORTH
CAROLINA AS OF THIS WRITING...WITH RAP SOUNDINGS SHOWING A DRY AIR
MASS FOR THE REST OF TODAY AND INTO TONIGHT. WATER VAPOR IMAGERY
SHOWED A MID-LEVEL SHORTWAVE MOVING INTO THE LOWER GREAT LAKES AND
OHIO VALLEY...AND THE SOUTHERN END OF THE WAVE SHOULD MOVE TOWARD
THE MOUNTAINS BY 20Z OR SO. IN LOOKING AT THE POTENTIAL FOR
OROGRAPHIC CIRRUS...A PRO IS THE APPROACH OF THE MID-LEVEL WAVE BUT
A CON IS THE SOUTHWEST FLOW ALOFT...WHICH MAY ACTUALLY RESULT IN AN
INCREASE IN UPPER-LEVEL CLOUDS DUE TO MOISTURE ADVECTION EFFECTS
ALOFT IN THE SOUTHWEST OR WEST-SOUTHWEST FLOW AHEAD OF THE MID-LEVEL
WAVE. BOTH THE CANADIAN CLOUD COVER MODEL AND THE LATEST HRRR WRF...
AND TO SOME EXTENT RAP HIGH-LEVEL RELATIVE HUMIDITY FIELDS...
INDICATE AN INCREASE IN SOME CIRRUS DURING THE AFTERNOON WITH A
FOCUS FROM THE SOUTHWEST PIEDMONT TOWARD THE CENTRAL COASTAL PLAIN
OR SO.
TEMPERATURES HAVE BEGUN TO RECOVER NICELY WITH THE SUN AND HIGHS
FROM 40 TO 45 SEEM REASONABLE...PRIOR TO FRONTAL PASSAGE LATE
TODAY...IN LINE WITH THE LATEST LAV GUIDANCE AND WHAT 1000-850MB
THICKNESSES WOULD PORTRAY. AS THE TEMPERATURES HAVE WARMED...WILL
CANCEL THE WINTER WEATHER ADVISORY FOR BLACK ICE FOR SAMPSON COUNTY.
MIXING THIS MORNING HAVE SHOWN A FEW GUSTS TO AT OR JUST ABOVE 20KT.
RAP SOUNDINGS SHOW THE POTENTIAL GUSTINESS SHOULD DIMINISH
SOME...INTO THE MID TEENS KNOTS...BY MID-AFTERNOON.
TONIGHT AND SATURDAY: REINFORCING...1041 MB ARCTIC HIGH PRESSURE
OVER MONTANA WILL BUILD SOUTHEASTWARD ACROSS THE PLAINS AND TN
VALLEY TONIGHT...AND ACROSS THE MIDDLE ATLANTIC REGION BY SAT.
THOUGH THIS HIGH IS NOT QUITE AS COLD AND STRONG AS THE PREDECESSOR
HIGH...IT WILL STILL RESULT IN UNSEASONABLY COLD CONDITIONS FOR
CENTRAL NC. IN FACT...PROJECTED 12Z LOW LEVEL THICKNESSE VALUES OF
AROUND 1260 METERS AT GSO SUPPORTS LOWS MOSTLY IN THE MIDDLE TEENS
TO AROUND 20 DEGREES. THE COLD...AND A 5-10 MPH NORTHWESTERLY WIND
USHERING THAT RENEWED ARCTIC AIR INTO CENTRAL NC...WILL PRODUCE WIND
CHILL VALUES IN THE SINGLE DIGITS ABOVE ZERO OVER THE PIEDMONT TO 10-
15 OVER THE SANDHILLS AND COASTAL PLAIN.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 245 AM FRIDAY...
THIS WILL BE A TRANSITION PERIOD AS THE UPPER LEVEL FLOW SHIFTS FROM
NORTHWEST TO SOUTHWESTERLY. RATHER STRONG SURFACE HIGH PRESSURE WILL
MIGRATE FROM THE OHIO VALLEY TO OFF THE MID ATLANTIC COAST DURING
THE PERIOD. THE SHORT TERM WEATHER WILL BE CHARACTERIZED AS DRY
WEATHER WITH BELOW NORMAL TEMPERATURES. MAINLY CLEAR SKIES SATURDAY
EVENING WILL GIVE WAY TO SOME INCREASING LATE AT NIGHT WITH CLOUDS
LOWERING AND THICKENING FROM THE SOUTHWEST ON SUNDAY. MAINLY CLEAR
SKIES ESPECIALLY INT HE EAST AND LIGHT WINDS WILL RESULT IN LOWS IN
THE 16-22 RANGE. HIGHS ON SUNDAY WILL MODERATE A BIT FROM SATURDAY
AND RANGE IN THE LOWER TO MID 40S. -BLAES
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...
AN UNSETTLED PATTERN WITH A GOOD DEAL OF UNCERTAINTY MAY LEAD TO A
CHANCE OF SOME WINTRY PRECIPITATION OVER OUR CLIMATOLOGICALLY
FAVORED LOCATIONS MID WEEK.
THE PATTERN ALOFT WILL COMPLETE ITS TRANSITION A SOUTHERN STREAM
DOMINANT...SOUTHWESTERLY FLOW EARLY IN THE LONG TERM AND CONTINUE
FOR MUCH OF THE PERIOD. THIS PATTERN TYPICALLY LEADS TO MORE
UNCERTAINTY THAN AVERAGE...OFTEN ALONG WITH UNSETTLED WEATHER AS LOW
AMPLITUDE WAVES MOVE QUICKLY IN THE FAST FLOW ALOFT. TIMING THESE
FEATURES AND RESOLVING DETAILS IS OFTEN PROBLEMATIC AS IS
IDENTIFYING POTENTIAL PHASING WITH THE NORTHERN STREAM.
WITH ALL OF THE CAVEATS OF OUT THE WAY...THE FIRST DISTURBANCE TO
AFFECT THE LONG TERM WILL ARRIVE LATE SUNDAY NIGHT AND CONTINUE INTO
MONDAY EVENING. STRENGTHENING ISENTROPIC LIFT EARLY MONDAY COMBINED
WITH A SHORT WAVE TROUGH LATE MONDAY SHOULD RESULT IN A COUPLE
BATCHES OF PRECIPITATION THAT SHOULD TAPER OFF MONDAY NIGHT. PARTIAL
THICKNESS VALUES FROM THE GFS/NAM/AND ALL SREF MEMBERS SUGGEST AN
ALL RAIN EVENT BUT SURFACE WET BULBS IN THE NORTHWEST PIEDMONT
SUGGEST A NARROW WINDOW OF FREEZING RAIN IS POSSIBLE AROUND ONSET
TIME. GIVEN THE LOCATION OF THE SURFACE HIGH AND THE THE TREND FOR
SLOWER PRECIP ARRIVAL...FAVOR AN ALL RAIN FORECAST FOR NOW BUT THIS
PART OF THE FORECAST WILL NEED TO BE MONITORED FOR THE POTENTIAL FOR
SOME FREEZING RAIN IN THE TRIAD AREA SUNDAY NIGHT AND VERY EARLY
MONDAY. LOWS SUNDAY NIGHT SHOULD RANGE IN THE LOWER TO MID 30S.
HIGHS WILL RANGE IN THE MID 40S IN THE NORTHWEST TO LOWER 50S IN THE
SOUTHEAST. LOWS MONDAY NIGHT WILL RANGE IN THE LOWER TO MID 30S
AGAIN.
UNCERTAINTY INCREASES A GREAT DEAL FOR TUESDAY THROUGH THURSDAY AS
MODEL GUIDANCE HAS TRENDED STRONGER WITH THE MIGRATING SURFACE HIGH
ACROSS THE GREAT LAKES AND NORTHEAST THAT RIDGES INTO THE PIEDMONT
OF VA AND THE CAROLINAS. THIS COLDER TREND AND STRONGER COLD AIR
DAMMING SIGNATURE LEADS TO A MORE SUPPRESSED PATTERN BUT ONE THAT
COULD SUPPORT SOME WINTRY PRECIPITATION...MAINLY ACROSS THE
CLIMATOLOGICALLY FAVORED LOCATIONS OF THE INTERIOR NORTHERN
PIEDMONT. WITH THE SOUTHERN SHIFT OF THE MAIN WEATHER FEATURES FOR
TUESDAY AND WEDNESDAY WE HAVE LOWERED POPS BELOW WPC GUIDANCE AND
SHIFTED THEM SOUTHWARD. THE TREND APPEARS TO BE FOR A LESS IMPACTFUL
SYSTEM. THE PRECIPITATION DURING THIS PERIOD WILL LARGELY RESULT
FROM SOME SHALLOW ISENTROPIC LIFT AND AN EJECTING SOUTHERN STREAM
SHORT WAVE TROUGH. LOW CHANCE POPS WILL BE INCLUDED FOR MOST OF THIS
PERIOD. WE HAVE INTRODUCED A SLIGHT CHANCE OF FREEZING RAIN ACROSS
THE NORTHWEST PIEDMONT FOR LATE TUESDAY NIGHT AND WEDNESDAY MORNING
WITH LOWS NEAR FREEZING...IF MORE WIDESPREAD PRECIPITATION
DEVELOPS...THESE TEMPS WILL BE TOO WARM AND THE WINTRY P-TYPE AREA
WOULD NEED TO BE EXPANDED. HIGHS BOTH DAYS WILL RANGE IN THE LOWER
40S NORTHWEST TO UPPER 40S SOUTHEAST.
AFTER A LULL LATE WEDNESDAY...BOTH THE GFS AND ECMWF INDICATE THE
POTENTIAL FOR A MORE ORGANIZED STORM SYSTEM ON THURSDAY AS SOME
NORTHERN AND SOUTHERN STREAM PHASING IS IMPLIED. THIS IS ALSO
SUPPORTED BY HALF OF THE GEFS ENSEMBLE MEMBERS AS WELL AS THE
PARALLEL GFS. THE SURFACE WAVE IS LIKELY TO BE WEAK AS IT MOVES
ACROSS THE MID ATLANTIC BEFORE STRENGTHENING OFFSHORE. A PERIOD OF
LIGHT PRECIPITATION IS POSSIBLE THURSDAY INTO THURSDAY NIGHT AND
FOR NOW IT APPEARS THE AIR MASS OVER CENTRAL NC WIL HAVE MODERATED
ENOUGH FOR AN ALL LIQUID EVENT WITH MORNING LOWS IN THE MID 30S TO
NEAR 40 AND AFTERNOON HIGHS IN THE 40S. -BLAES
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1250 PM FRIDAY...
VFR CONDITIONS WILL CONTINUE THROUGH THE 18Z VALID TAF PERIOD AND
BEYOND...AT LEAST INTO THE DAY SUNDAY. SUB-VFR CONDITIONS IN LOW
CLOUDS AND AREAS OF PRECIPITATION ARE LIKELY BY LATE SUNDAY NIGHT
AND CONTINUING INTO MONDAY AS A LOW PRESSURE SYSTEM MOVES NORTH
ALONG THE CAROLINA COAST. A BRIEF RETURN TO VFR CONDITIONS IS
POSSIBLE BY TUESDAY...THEN OVERNIGHT TUESDAY SUB-VFR CONDITIONS ONCE
AGAIN APPEAR POSSIBLE...MVFR THE LIKELY CATEGORY IF IT OCCURS...
WITH MORE AREAS OF PRECIPITATION. AVIATION INTERESTS SHOULD KEEP
ABREAST OF THE LATEST FORECASTS FOR PRECIPITATION NEAR AND NORTHWEST
OF THE TRIAD LATE SUNDAY NIGHT INTO EARLY MONDAY...AND ACROSS
CENTRAL NORTH CAROLINA ESPECIALLY TUESDAY NIGHT WITH REGARD TO
PRECIPITATION TYPE...TEMPERATURE...AND TIMING. CONDITIONS ARE
CURRENTLY EXPECTED TO RETURN TO VFR ON WEDNESDAY. THROUGH TONIGHT
INTO SATURDAY...WINDS WILL GRADUALLY VEER...BECOMING NORTHWEST
TONIGHT AND NORTH EARLY SATURDAY...WITH SOME GUSTINESS LIKELY INTO
THE TEENS KNOTS WITH MIXING SATURDAY MORNING BEFORE WINDS DIMINISH
DURING THE DAY AS HIGH PRESSURE BUILDS IN.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...MWS/DJF
SHORT TERM...BLAES
LONG TERM...BLAES
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1050 AM EST FRI JAN 9 2015
.SYNOPSIS...
ARCTIC HIGH PRESSURE WILL DRIFT SOUTH OF THE CAROLINAS
TODAY...IN ADVANCE OF AN ARCTIC COLD FRONT THAT WILL CROSS CENTRAL
NC THIS AFTERNOON AND EVENING. REINFORCING ARCTIC HIGH PRESSURE WILL
FOLLOW AND EXTEND INTO THE MIDDLE ATLANTIC REGION THIS WEEKEND. A
SERIES OF UPPER LEVEL DISTURBANCES WILL RESULT IN UNSETTLED WEATHER
SUNDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1050 AM FRIDAY...
CLEARING HAS OCCURRED THROUGHOUT VIRTUALLY ALL OF CENTRAL NORTH
CAROLINA AS OF THIS WRITING...WITH RAP SOUNDINGS SHOWING A DRY AIR
MASS FOR THE REST OF TODAY AND INTO TONIGHT. WATER VAPOR IMAGERY
SHOWED A MID-LEVEL SHORTWAVE MOVING INTO THE LOWER GREAT LAKES AND
OHIO VALLEY...AND THE SOUTHERN END OF THE WAVE SHOULD MOVE TOWARD
THE MOUNTAINS BY 20Z OR SO. IN LOOKING AT THE POTENTIAL FOR
OROGRAPHIC CIRRUS...A PRO IS THE APPROACH OF THE MID-LEVEL WAVE BUT
A CON IS THE SOUTHWEST FLOW ALOFT...WHICH MAY ACTUALLY RESULT IN AN
INCREASE IN UPPER-LEVEL CLOUDS DUE TO MOISTURE ADVECTION EFFECTS
ALOFT IN THE SOUTHWEST OR WEST-SOUTHWEST FLOW AHEAD OF THE MID-LEVEL
WAVE. BOTH THE CANADIAN CLOUD COVER MODEL AND THE LATEST HRRR WRF...
AND TO SOME EXTENT RAP HIGH-LEVEL RELATIVE HUMIDITY FIELDS...
INDICATE AN INCREASE IN SOME CIRRUS DURING THE AFTERNOON WITH A
FOCUS FROM THE SOUTHWEST PIEDMONT TOWARD THE CENTRAL COASTAL PLAIN
OR SO.
TEMPERATURES HAVE BEGUN TO RECOVER NICELY WITH THE SUN AND HIGHS
FROM 40 TO 45 SEEM REASONABLE...PRIOR TO FRONTAL PASSAGE LATE
TODAY...IN LINE WITH THE LATEST LAV GUIDANCE AND WHAT 1000-850MB
THICKNESSES WOULD PORTRAY. AS THE TEMPERATURES HAVE WARMED...WILL
CANCEL THE WINTER WEATHER ADVISORY FOR BLACK ICE FOR SAMPSON COUNTY.
MIXING THIS MORNING HAVE SHOWN A FEW GUSTS TO AT OR JUST ABOVE 20KT.
RAP SOUNDINGS SHOW THE POTENTIAL GUSTINESS SHOULD DIMINISH
SOME...INTO THE MID TEENS KNOTS...BY MID-AFTERNOON.
TONIGHT AND SATURDAY: REINFORCING...1041 MB ARCTIC HIGH PRESSURE
OVER MONTANA WILL BUILD SOUTHEASTWARD ACROSS THE PLAINS AND TN
VALLEY TONIGHT...AND ACROSS THE MIDDLE ATLANTIC REGION BY SAT.
THOUGH THIS HIGH IS NOT QUITE AS COLD AND STRONG AS THE PREDECESSOR
HIGH...IT WILL STILL RESULT IN UNSEASONABLY COLD CONDITIONS FOR
CENTRAL NC. IN FACT...PROJECTED 12Z LOW LEVEL THICKNESSE VALUES OF
AROUND 1260 METERS AT GSO SUPPORTS LOWS MOSTLY IN THE MIDDLE TEENS
TO AROUND 20 DEGREES. THE COLD...AND A 5-10 MPH NORTHWESTERLY WIND
USHERING THAT RENEWED ARCTIC AIR INTO CENTRAL NC...WILL PRODUCE WIND
CHILL VALUES IN THE SINGLE DIGITS ABOVE ZERO OVER THE PIEDMONT TO 10-
15 OVER THE SANDHILLS AND COASTAL PLAIN.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 245 AM FRIDAY...
THIS WILL BE A TRANSITION PERIOD AS THE UPPER LEVEL FLOW SHIFTS FROM
NORTHWEST TO SOUTHWESTERLY. RATHER STRONG SURFACE HIGH PRESSURE WILL
MIGRATE FROM THE OHIO VALLEY TO OFF THE MID ATLANTIC COAST DURING
THE PERIOD. THE SHORT TERM WEATHER WILL BE CHARACTERIZED AS DRY
WEATHER WITH BELOW NORMAL TEMPERATURES. MAINLY CLEAR SKIES SATURDAY
EVENING WILL GIVE WAY TO SOME INCREASING LATE AT NIGHT WITH CLOUDS
LOWERING AND THICKENING FROM THE SOUTHWEST ON SUNDAY. MAINLY CLEAR
SKIES ESPECIALLY INT HE EAST AND LIGHT WINDS WILL RESULT IN LOWS IN
THE 16-22 RANGE. HIGHS ON SUNDAY WILL MODERATE A BIT FROM SATURDAY
AND RANGE IN THE LOWER TO MID 40S. -BLAES
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 320 AM FRIDAY...
AN UNSETTLED PATTERN WITH A GOOD DEAL OF UNCERTAINTY MAY LEAD TO A
CHANCE OF SOME WINTRY PRECIPITATION OVER OUR CLIMATOLOGICALLY
FAVORED LOCATIONS MID WEEK.
THE PATTERN ALOFT WILL COMPLETE ITS TRANSITION A SOUTHERN STREAM
DOMINANT...SOUTHWESTERLY FLOW EARLY IN THE LONG TERM AND CONTINUE
FOR MUCH OF THE PERIOD. THIS PATTERN TYPICALLY LEADS TO MORE
UNCERTAINTY THAN AVERAGE...OFTEN ALONG WITH UNSETTLED WEATHER AS LOW
AMPLITUDE WAVES MOVE QUICKLY IN THE FAST FLOW ALOFT. TIMING THESE
FEATURES AND RESOLVING DETAILS IS OFTEN PROBLEMATIC AS IS
IDENTIFYING POTENTIAL PHASING WITH THE NORTHERN STREAM.
WITH ALL OF THE CAVEATS OF OUT THE WAY...THE FIRST DISTURBANCE TO
AFFECT THE LONG TERM WILL ARRIVE LATE SUNDAY NIGHT AND CONTINUE INTO
MONDAY EVENING. STRENGTHENING ISENTROPIC LIFT EARLY MONDAY COMBINED
WITH A SHORT WAVE TROUGH LATE MONDAY SHOULD RESULT IN A COUPLE
BATCHES OF PRECIPITATION THAT SHOULD TAPER OFF MONDAY NIGHT. PARTIAL
THICKNESS VALUES FROM THE GFS/NAM/AND ALL SREF MEMBERS SUGGEST AN
ALL RAIN EVENT BUT SURFACE WET BULBS IN THE NORTHWEST PIEDMONT
SUGGEST A NARROW WINDOW OF FREEZING RAIN IS POSSIBLE AROUND ONSET
TIME. GIVEN THE LOCATION OF THE SURFACE HIGH AND THE THE TREND FOR
SLOWER PRECIP ARRIVAL...FAVOR AN ALL RAIN FORECAST FOR NOW BUT THIS
PART OF THE FORECAST WILL NEED TO BE MONITORED FOR THE POTENTIAL FOR
SOME FREEZING RAIN IN THE TRIAD AREA SUNDAY NIGHT AND VERY EARLY
MONDAY. LOWS SUNDAY NIGHT SHOULD RANGE IN THE LOWER TO MID 30S.
HIGHS WILL RANGE IN THE MID 40S IN THE NORTHWEST TO LOWER 50S IN THE
SOUTHEAST. LOWS MONDAY NIGHT WILL RANGE IN THE LOWER TO MID 30S
AGAIN.
UNCERTAINTY INCREASES A GREAT DEAL FOR TUESDAY THROUGH THURSDAY AS
MODEL GUIDANCE HAS TRENDED STRONGER WITH THE MIGRATING SURFACE HIGH
ACROSS THE GREAT LAKES AND NORTHEAST THAT RIDGES INTO THE PIEDMONT
OF VA AND THE CAROLINAS. THIS COLDER TREND AND STRONGER COLD AIR
DAMMING SIGNATURE LEADS TO A MORE SUPPRESSED PATTERN BUT ONE THAT
COULD SUPPORT SOME WINTRY PRECIPITATION...MAINLY ACROSS THE
CLIMATOLOGICALLY FAVORED LOCATIONS OF THE INTERIOR NORTHERN
PIEDMONT. WITH THE SOUTHERN SHIFT OF THE MAIN WEATHER FEATURES FOR
TUESDAY AND WEDNESDAY WE HAVE LOWERED POPS BELOW WPC GUIDANCE AND
SHIFTED THEM SOUTHWARD. THE TREND APPEARS TO BE FOR A LESS IMPACTFUL
SYSTEM. THE PRECIPITATION DURING THIS PERIOD WILL LARGELY RESULT
FROM SOME SHALLOW ISENTROPIC LIFT AND AN EJECTING SOUTHERN STREAM
SHORT WAVE TROUGH. LOW CHANCE POPS WILL BE INCLUDED FOR MOST OF THIS
PERIOD. WE HAVE INTRODUCED A SLIGHT CHANCE OF FREEZING RAIN ACROSS
THE NORTHWEST PIEDMONT FOR LATE TUESDAY NIGHT AND WEDNESDAY MORNING
WITH LOWS NEAR FREEZING...IF MORE WIDESPREAD PRECIPITATION
DEVELOPS...THESE TEMPS WILL BE TOO WARM AND THE WINTRY P-TYPE AREA
WOULD NEED TO BE EXPANDED. HIGHS BOTH DAYS WILL RANGE IN THE LOWER
40S NORTHWEST TO UPPER 40S SOUTHEAST.
AFTER A LULL LATE WEDNESDAY...BOTH THE GFS AND ECMWF INDICATE THE
POTENTIAL FOR A MORE ORGANIZED STORM SYSTEM ON THURSDAY AS SOME
NORTHERN AND SOUTHERN STREAM PHASING IS IMPLIED. THIS IS ALSO
SUPPORTED BY HALF OF THE GEFS ENSEMBLE MEMBERS AS WELL AS THE
PARALLEL GFS. THE SURFACE WAVE IS LIKELY TO BE WEAK AS IT MOVES
ACROSS THE MID ATLANTIC BEFORE STRENGTHENING OFFSHORE. A PERIOD OF
LIGHT PRECIPITATION IS POSSIBLE THURSDAY INTO THURSDAY NIGHT AND
FOR NOW IT APPEARS THE AIR MASS OVER CENTRAL NC WIL HAVE MODERATED
ENOUGH FOR AN ALL LIQUID EVENT WITH MORNING LOWS IN THE MID 30S TO
NEAR 40 AND AFTERNOON HIGHS IN THE 40S. -BLAES
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AS OF 1050 AM FRIDAY...
EXPECT VFR CONDITIONS WITH SOME PASSING MID-HIGH CLOUDS THAT WILL
HAVE RELATIVE GREATEST COVERAGE LATE AFTERNOON AND THIS EVENING.
SOUTHWESTERLY TO WEST SOUTHWESTERLY SURFACE WINDS BETWEEN 8-15 KTS
MAY BE BRIEFLY GUSTY TO AROUND 20 KTS...AS THE LOW LEVEL WIND SHEAR-
INDUCING LOW LEVEL JET MIXES OUT AND LIFTS AWAY FROM CENTRAL NC.
WINDS WILL THEN VEER TO WESTERLY AND NORTHWESTERLY BEHIND A DRY/VFR
COLD FRONT THAT WILL CROSS OUR REGION LATE THIS AFTERNOON AND
EVENING.
OUTLOOK: WAVES OF LOW PRESSURE FROM THE GULF TO SE COASTS WILL
INTERACT WITH A SERIES OF ARCTIC HIGHS ACROSS THE GREAT LAKES AND
NEW ENGLAND...WHICH WILL RESULT IN A POTENTIALLY PROLONGED THREAT OF
MVFR-IFR CONDITIONS --AND WET TO WINTRY CONDITIONS- SUN NIGHT
THROUGH EARLY TO MID NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS/DJF
SHORT TERM...BLAES
LONG TERM...BLAES
AVIATION...MWS/DJF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
932 PM CST SAT JAN 10 2015
.UPDATE...
ISSUED AT 923 PM CST SAT JAN 10 2015
MAIN CHANGE FOR LATE EVENING UPDATE WAS TO RAISE LOW TEMPERATURES
A BIT OVER THE NORTH CENTRAL AS CLOUD COVER HAS PUSHED WELL INTO
THE AREA. HAVE ALSO ADJUSTED POPS UP A LITTLE OVER THE
WEST...ALTHOUGH STILL SOME QUESTION ON HOW MUCH SNOW IF ANY WILL
MAKE IT TO THE GROUND WITH A RELATIVELY DRY LOWER ATMOSPHERE.
UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 625 PM CST SAT JAN 10 2015
PREVIOUS FORECAST WAS IN PRETTY GOOD SHAPE WITH ONLY CHANGE BEING
ADVANCING CLOUDS A LITTLE FASTER THAN PREVIOUSLY THOUGHT.
OTHERWISE...SNOW CHANCES CONTINUE FOR LATER THIS EVENING MAINLY
WEST INTO PORTIONS OF SOUTH CENTRAL. WILL KEEP AN EYE ON HOW THIS
EVOLVES OVER MONTANA TO SEE IF ANY CHANGES ARE NEEDED ON
SUBSEQUENT UPDATES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM CST SAT JAN 10 2015
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS SNOW CHANCES
WITH AN APPROACHING SHORTWAVE LATE TONIGHT THROUGH SUNDAY
MORNING...AND WIND CHILLS NORTH TONIGHT THROUGH MIDDAY SUNDAY.
A SHORTWAVE MOVING THROUGH MEAN WRN CANADA UPPER RIDGE CURRENTLY
MOVING FROM BRITISH COLUMBIA INTO ALBERTA...WILL COMBINE WITH A
NORTHERN STREAM SAVE DROPPING SOUTH FROM THE NORTHWEST TERRITORIES
AND MOVE INTO THE NORTHERN PLAINS LATE TONIGHT INTO SUNDAY. MID
LEVEL FORCING WILL PRODUCE A BAND OF LIGHT SNOW SPREADING FROM THE
LEE OF THE CANADIAN ROCKIES INTO EASTERN MONTANA THIS
EVENING...AND THEN ACROSS WESTERN NORTH DAKOTA AND INTO NORTHERN
SOUTH DAKOTA LATE TONIGHT THROUGH SUNDAY MORNING. THE TREND FROM
PREVIOUS RUNS HAS BEEN A LITTLE FARTHER NORTH WITH THE LIGHT
SNOW. HAVE UTILIZED BASICALLY A BLEND OF DETERMINISTIC GUIDANCE
WHICH BRINGS SLIGHT CHANCE TO CHANCE POPS MAINLY WEST AND SOUTH OF
LAKE SAKAKAWEA AND THE MISSOURI RIVER TONIGHT AND INTO THE FAR
SOUTH CENTRAL SUNDAY MORNING. THE LATEST MESOSCALE RAP AND HRRR
CONTINUE TO BRING THE BAND OF LIGHT SNOW EVEN A LITTLE FARTHER
NORTH...LIFTING NORTH AND EAST OF THE MISSOURI. WILL STICK WITH
THE CURRENT BLEND FOR NOW. SNOW AMOUNTS ARE EXPECTED TO BE LIGHT
WITH UNDER A HALF INCH...WITH POSSIBLY A HALF INCH TO AN INCH FROM
THE WEST CENTRAL INTO SOUTHWEST NORTH DAKOTA.
TO THE NORTH AND EAST...TEMPERATURES ARE IN THE SINGLE DIGITS
ABOVE ZERO ALONG THE CANADIAN BORDER...AND SHOULD DROP QUICKLY
THIS EVENING. WINDS WILL NOT BE STRONG BUT A STEADY 5 TO 10 MPH.
THIS WILL PRODUCE ADVISORY CRITERIA WINDS AGAIN LATE THIS EVENING
THROUGH SUNDAY MORNING ALONG THE CANADIAN BORDER. WILL ISSUE
ANOTHER ADVISORY TO COVER THIS.
SUNDAY WILL BRING TEMPERATURES SIMILAR TO TODAY WITH HIGHS FROM
NEAR ZERO NORTHEAST TO THE LOWER TEENS SOUTHWEST AND SOUTH
CENTRAL.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM CST SAT JAN 10 2015
COLD WITH DANGEROUS WIND CHILLS SUNDAY NIGHT...FOLLOWED BY A WARMING
TREND.
UPPER LEVEL NORTHWEST FLOW AND A LARGE SURFACE ARCTIC HIGH PRESSURE
SYSTEM WILL BE IN PLACE SUNDAY EVENING...WITH THE FORECAST CENTER OF
THE ARCTIC HIGH OVER SOUTHEASTERN SASKATCHEWAN/NORTHWESTERN
NORTH DAKOTA AROUND SUNSET SUNDAY EVENING. THE HIGH CENTER MOVES
SOUTHEAST ACROSS THE STATE SUNDAY NIGHT. BY DAYBREAK MONDAY MORNING
THE HIGH CENTER SHOULD BE OVER THE EASTERN DAKOTAS. NORTHWEST WINDS
SHOULD BE RATHER LIGHT - 5 TO 10 MPH SUNDAY EVENING AND UP TO 5 MPH
LATE SUNDAY NIGHT. LOW TEMPERATURES SHOULD BOTTOM OUT AROUND 15 TO
20 BELOW OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA. THE HIGH
CENTER SHOULD BE NORTH AND EAST OF THE SOUTHWESTERN PORTION OF THE
STATE...AND THERE THE OVERNIGHT LOWS SHOULD BE IN THE 10 TO 15 BELOW
ZERO RANGE. THESE MINIMUM TEMPERATURES COMBINED WITH THE WINDS UP TO
10 MPH AT TIMES WILL COMBINE TO PRODUCE WIND CHILLS IN THE 25 TO 30
BELOW ZERO RANGE (PERHAPS SOME ISOLATED LOCALES REACHING 35 BELOW
ZERO WIND CHILLS) FOR ALL BUT THE FAR SOUTHWESTERN COUNTIES OF NORTH
DAKOTA.
MONDAY AND MONDAY NIGHT: THE ARCTIC HIGH PRESSURE WILL CONTINUE
MOVING SOUTHEAST...AND THE UPPER LEVEL FLOW BEGINS CHANGING FROM
NORTHWEST TO A MORE ZONAL FLOW. LOOKING AT HIGHS MONDAY FROM JUST
ABOVE ZERO IN THE TURTLE MOUNTAINS AND JAMES RIVER VALLEY...TO THE
LOWER TEENS IN THE SOUTHWEST. LOWS WILL STILL BE BELOW ZERO MONDAY
NIGHT AS THE RESIDUAL ARCTIC AIR REMAINS OVER THE REGION.
THE CHANGING WEATHER PATTERN SHOULD BEGIN TO BE FELT ON TUESDAY AS
AN UPPER LEVEL RIDGE BEGINS BUILDING INTO THE WESTERN PLAINS...AND
AS SOUTHERLY SURFACE WINDS BEGIN TO BRING A MILDER PACIFIC AIRMASS
INTO THE REGION. LOOKING AT HIGHS TUESDAY IN THE TEENS AND LOWER 20S.
DRY CONDITIONS WILL CONTINUE AND TEMPERATURES WILL CONTINUE TO
MODERATE THROUGH THE WEEK AS PACIFIC RIDGING CONTINUES TO BUILD.
HIGHS ARE FORECAST TO BE AROUND AVERAGE (20S TO LOWER 30S) ON
WEDNESDAY...AND ABOVE AVERAGE (UPPER 20S TO MID/UPPER 30S) THURSDAY
THROUGH SATURDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 625 PM CST SAT JAN 10 2015
LCL MVFR CIGS POSSIBLE OVER WESTERN AND SOUTH CENTRAL NORTH DAKOTA
LATE TONIGHT INTO EARLY SATURDAY MORNING WITH POSSIBLE -SN.
OTHERWISE...VFR CONDITIONS ARE EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST SUNDAY FOR NDZ002>005-011>013.
&&
$$
UPDATE...JJS
SHORT TERM...TWH
LONG TERM...JV
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
630 PM CST SAT JAN 10 2015
.UPDATE...
ISSUED AT 625 PM CST SAT JAN 10 2015
PREVIOUS FORECAST WAS IN PRETTY GOOD SHAPE WITH ONLY CHANGE BEING
ADVANCING CLOUDS A LITTLE FASTER THAN PREVIOUSLY THOUGHT.
OTHERWISE...SNOW CHANCES CONTINUE FOR LATER THIS EVENING MAINLY
WEST INTO PORTIONS OF SOUTH CENTRAL. WILL KEEP AN EYE ON HOW THIS
EVOLVES OVER MONTANA TO SEE IF ANY CHANGES ARE NEEDED ON
SUBSEQUENT UPDATES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM CST SAT JAN 10 2015
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS SNOW CHANCES
WITH AN APPROACHING SHORTWAVE LATE TONIGHT THROUGH SUNDAY
MORNING...AND WIND CHILLS NORTH TONIGHT THROUGH MIDDAY SUNDAY.
A SHORTWAVE MOVING THROUGH MEAN WRN CANADA UPPER RIDGE CURRENTLY
MOVING FROM BRITISH COLUMBIA INTO ALBERTA...WILL COMBINE WITH A
NORTHERN STREAM SAVE DROPPING SOUTH FROM THE NORTHWEST TERRITORIES
AND MOVE INTO THE NORTHERN PLAINS LATE TONIGHT INTO SUNDAY. MID
LEVEL FORCING WILL PRODUCE A BAND OF LIGHT SNOW SPREADING FROM THE
LEE OF THE CANADIAN ROCKIES INTO EASTERN MONTANA THIS
EVENING...AND THEN ACROSS WESTERN NORTH DAKOTA AND INTO NORTHERN
SOUTH DAKOTA LATE TONIGHT THROUGH SUNDAY MORNING. THE TREND FROM
PREVIOUS RUNS HAS BEEN A LITTLE FARTHER NORTH WITH THE LIGHT
SNOW. HAVE UTILIZED BASICALLY A BLEND OF DETERMINISTIC GUIDANCE
WHICH BRINGS SLIGHT CHANCE TO CHANCE POPS MAINLY WEST AND SOUTH OF
LAKE SAKAKAWEA AND THE MISSOURI RIVER TONIGHT AND INTO THE FAR
SOUTH CENTRAL SUNDAY MORNING. THE LATEST MESOSCALE RAP AND HRRR
CONTINUE TO BRING THE BAND OF LIGHT SNOW EVEN A LITTLE FARTHER
NORTH...LIFTING NORTH AND EAST OF THE MISSOURI. WILL STICK WITH
THE CURRENT BLEND FOR NOW. SNOW AMOUNTS ARE EXPECTED TO BE LIGHT
WITH UNDER A HALF INCH...WITH POSSIBLY A HALF INCH TO AN INCH FROM
THE WEST CENTRAL INTO SOUTHWEST NORTH DAKOTA.
TO THE NORTH AND EAST...TEMPERATURES ARE IN THE SINGLE DIGITS
ABOVE ZERO ALONG THE CANADIAN BORDER...AND SHOULD DROP QUICKLY
THIS EVENING. WINDS WILL NOT BE STRONG BUT A STEADY 5 TO 10 MPH.
THIS WILL PRODUCE ADVISORY CRITERIA WINDS AGAIN LATE THIS EVENING
THROUGH SUNDAY MORNING ALONG THE CANADIAN BORDER. WILL ISSUE
ANOTHER ADVISORY TO COVER THIS.
SUNDAY WILL BRING TEMPERATURES SIMILAR TO TODAY WITH HIGHS FROM
NEAR ZERO NORTHEAST TO THE LOWER TEENS SOUTHWEST AND SOUTH
CENTRAL.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM CST SAT JAN 10 2015
COLD WITH DANGEROUS WIND CHILLS SUNDAY NIGHT...FOLLOWED BY A WARMING
TREND.
UPPER LEVEL NORTHWEST FLOW AND A LARGE SURFACE ARCTIC HIGH PRESSURE
SYSTEM WILL BE IN PLACE SUNDAY EVENING...WITH THE FORECAST CENTER OF
THE ARCTIC HIGH OVER SOUTHEASTERN SASKATCHEWAN/NORTHWESTERN
NORTH DAKOTA AROUND SUNSET SUNDAY EVENING. THE HIGH CENTER MOVES
SOUTHEAST ACROSS THE STATE SUNDAY NIGHT. BY DAYBREAK MONDAY MORNING
THE HIGH CENTER SHOULD BE OVER THE EASTERN DAKOTAS. NORTHWEST WINDS
SHOULD BE RATHER LIGHT - 5 TO 10 MPH SUNDAY EVENING AND UP TO 5 MPH
LATE SUNDAY NIGHT. LOW TEMPERATURES SHOULD BOTTOM OUT AROUND 15 TO
20 BELOW OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA. THE HIGH
CENTER SHOULD BE NORTH AND EAST OF THE SOUTHWESTERN PORTION OF THE
STATE...AND THERE THE OVERNIGHT LOWS SHOULD BE IN THE 10 TO 15 BELOW
ZERO RANGE. THESE MINIMUM TEMPERATURES COMBINED WITH THE WINDS UP TO
10 MPH AT TIMES WILL COMBINE TO PRODUCE WIND CHILLS IN THE 25 TO 30
BELOW ZERO RANGE (PERHAPS SOME ISOLATED LOCALES REACHING 35 BELOW
ZERO WIND CHILLS) FOR ALL BUT THE FAR SOUTHWESTERN COUNTIES OF NORTH
DAKOTA.
MONDAY AND MONDAY NIGHT: THE ARCTIC HIGH PRESSURE WILL CONTINUE
MOVING SOUTHEAST...AND THE UPPER LEVEL FLOW BEGINS CHANGING FROM
NORTHWEST TO A MORE ZONAL FLOW. LOOKING AT HIGHS MONDAY FROM JUST
ABOVE ZERO IN THE TURTLE MOUNTAINS AND JAMES RIVER VALLEY...TO THE
LOWER TEENS IN THE SOUTHWEST. LOWS WILL STILL BE BELOW ZERO MONDAY
NIGHT AS THE RESIDUAL ARCTIC AIR REMAINS OVER THE REGION.
THE CHANGING WEATHER PATTERN SHOULD BEGIN TO BE FELT ON TUESDAY AS
AN UPPER LEVEL RIDGE BEGINS BUILDING INTO THE WESTERN PLAINS...AND
AS SOUTHERLY SURFACE WINDS BEGIN TO BRING A MILDER PACIFIC AIRMASS
INTO THE REGION. LOOKING AT HIGHS TUESDAY IN THE TEENS AND LOWER 20S.
DRY CONDITIONS WILL CONTINUE AND TEMPERATURES WILL CONTINUE TO
MODERATE THROUGH THE WEEK AS PACIFIC RIDGING CONTINUES TO BUILD.
HIGHS ARE FORECAST TO BE AROUND AVERAGE (20S TO LOWER 30S) ON
WEDNESDAY...AND ABOVE AVERAGE (UPPER 20S TO MID/UPPER 30S) THURSDAY
THROUGH SATURDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 625 PM CST SAT JAN 10 2015
LCL MVFR CIGS POSSIBLE OVER WESTERN AND SOUTH CENTRAL NORTH DAKOTA
LATE TONIGHT INTO EARLY SATURDAY MORNING WITH POSSIBLE -SN.
OTHERWISE...VFR CONDITIONS ARE EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 10 PM THIS EVENING TO NOON CST SUNDAY
FOR NDZ002>005-011>013.
&&
$$
UPDATE...JJS
SHORT TERM...TWH
LONG TERM...JV
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS TULSA OK
934 PM CST SAT JAN 10 2015
...UPDATE...
.DISCUSSION...
UPPER WAVE CURRENTLY OVER FAR WEST TX WILL LIFT NORTHEASTWARD
ACROSS THE LOCAL REGION DURING THE DAY ON SUNDAY. PRECIPITATION
HAS BEGUN TO EXPAND ACROSS SOUTH CENTRAL TX AND THIS WILL SPREAD
NORTHEASTWARD OVERNIGHT AND THROUGH THE DAY ON SUNDAY. CURRENTLY
LOW LEVEL CONDITIONS REMAIN VERY DRY ACROSS THE AREA BUT WILL
MOISTEN AS PRECIPITATION INTENSITY INCREASES OVERNIGHT. SFC TEMPS
REMAIN THE LARGEST VARIABLE CONCERNING PRECIPITATION TYPE AS A
STOUT WARM LAYER ALOFT WILL ENSURE COMPLETE MELTING OF DROPLETS.
INITIAL PRECIP WILL LIKELY RESULT IN A BRIEF PERIOD OF WET BULB
COOLING HOWEVER SUSTAINED WARM ADVECTION ALONG WITH FURTHER
WARMING POTENTIAL WITHIN HEAVIER PRECIP BANDS SUGGESTS ANY COOLING
WILL BE BRIEF. THIS ALIGNS WILL ALL AVAILABLE HOURLY GUIDANCE SFC
TRENDS AND W/ THE EARLIER FORECAST THOUGHTS. THE END RESULT IS A
FZRA / RA MIX W/ LIMITED POTENTIAL FOR ICE ACCUMULATIONS. ELEVATED
SFCS AND THE MORE SHELTERED VALLEYS OF NW AR AND FAR SE OK WILL BE
MOST PRONE TO MEASURABLE ICE ACCUMULATIONS...AND EVEN THEN THE
AMOUNTS ARE EXPECTED TO REMAIN LIGHT.
THE UPDATED FORECAST WILL EXPAND HIGH PRECIP CHANCES ACROSS SE OK
PER CONSISTENT TRENDS IN HRRR DATA. OTHERWISE THE FORECAST IS
TRACKING WELL WITH MINIMAL ADJUSTMENTS NEEDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 28 38 30 35 / 10 20 20 10
FSM 29 37 33 41 / 50 90 40 20
MLC 31 38 32 38 / 60 60 20 10
BVO 27 39 27 32 / 10 20 20 10
FYV 28 38 31 36 / 30 70 40 20
BYV 27 38 32 35 / 20 70 50 20
MKO 29 38 31 36 / 40 50 20 10
MIO 27 37 28 33 / 10 30 30 10
F10 30 39 31 35 / 30 30 20 10
HHW 31 38 34 44 / 80 90 20 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON SUNDAY FOR OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL NOON SUNDAY FOR ARZ002-ARZ011-
ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...07
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
407 AM MST FRI JAN 9 2015
.SYNOPSIS...
WINTER WEATHER CONTINUES AROUND THE AREA TODAY AS ANOTHER COLD FRONT
WILL PUSH WEST ACROSS THE BORDERLAND LATE THIS MORNING AND AFTERNOON
WITH BREEZY WINDS. TEMPERATURES ACROSS THE LOWLANDS SHOULD REMAIN
ABOVE FREEZING SO EXPECT JUST SOME LIGHT COLD RAIN. MOUNTAIN
AREAS...ESPECIALLY ABOVE 7500 FEET...COULD SEE ONE TO THREE INCHES
OF SNOW BY THIS EVENING. AS THE UPPER LOW MOVES EAST ACROSS NORTHERN
MEXICO SOME AREAS OF LIGHT RAIN AND MOUNTAIN SNOW WILL CONTINUE
THROUGH MUCH OF SATURDAY BEFORE THE LOW AND MOISTURE MOVE INTO
CENTRAL TEXAS SATURDAY NIGHT. AN UPPER TROUGH MOVES ACROSS NEW
MEXICO MONDAY..SPREADING SOME SHOWERS MONDAY AND MONDAY
NIGHT...MAINLY TO THE MOUNTAINS. TUESDAY AND WEDNESDAY LOOK TO BE
DRIER WITH LESS CLOUDS. TEMPERATURES WILL REMAIN BELOW NORMAL
THROUGH SATURDAY BEFORE WARMING BACK TO NORMAL SUNDAY AND MONDAY.
&&
.DISCUSSION...
WINTER WEATHER WILL CONTINUE ANOTHER DAY OR TWO AROUND THE
BORDERLAND AS AN UPPER LOW WELL SOUTH OF TUCSON DRIFTS EAST ACROSS
NORTHERN MEXICO. MAIN (ONLY) PRECIP BAND EXTENDS FROM THE GILA
MOUNTAINS EAST ACROSS SIERRA COUNT AND OVER TO THE SACRAMENTO
MOUNTAINS. THIS BAND LIES IN A RATHER PERSISTENT DEFORMATION ZONE.
WV IMAGERY SHOWS A GRAVITY WAVE MOVED OUT OF WESTERN KANSAS LAST
NIGHT AND DOWN TO THIS DEFORMATION ZONE EARLY THIS MORNING...PERHAPS
ENHANCING THE PRECIP A BIT. MESONET OBS SHOW SNOW LEVELS OVER THE
GILA AROUND 7500-8000 FT...WHILE OVER THE SACS THE SNOW LEVEL LOOKS
TO BE AROUND 6500 FT. CLOUDCROFT WEBCAMS SHOW SOME LIGHT SNOW THERE
AND BOTH AREA MOUNTAINS COULD SEE 1-3 INCHES OF SNOW AT THEIR
RESPECTIVE SNOW LEVELS THROUGH TONIGHT. AT THE SURFACE ANOTHER BACK
DOOR COLD FRONT IS RAPIDLY DROPPING SOUTH TO THE AREA. SATELLITE/OBS
SHOW FRONT JUST AN HOUR OR TWO NORTH OF RUIDOSO AND ROSWELL AND
SHOULD REACH THE SACS WITHIN A COUPLE OF HOURS. HRRR SHOWS IT
REACHING THE RIO GRANDE VALLEY SHORTLY AFTER SUNRISE. EXPECT BRIEF
GUSTY WINDS ALONG WEST SLOPES OF THE FRANKLIN/ORGAN MOUNTAINS
AGAIN...FROM ABOUT 9AM TO 2PM. COULD BRIEFLY REACH ADVISORY CRITERIA
BUT WILL NOT ISSUE ONE AT THIS TIME. MODELS SHOWING THIS FRONT
COOLING MOST OF THE ATMOSPHERE AND RENDERING THE FREEZING PRECIP
PROFILE OBSOLETE.
SOME PRECIP LIKELY TO CONTINUE SATURDAY. BY SATURDAY AFTERNOON THE
LOW IS OVER THE BIG BEND REGION AS IT WEAKENS. BY SATURDAY EVENING
IT IS PAST THE PERMIAN BASIN AND SHOULD ALLOW MOST OR ALL PRECIP TO
END. IF SOME PRECIP LINGERS INTO THE LATE EVENING HOURS...LOWLANDS
COULD SEE A MIXTURE OF RAIN AND SNOW BUT WITH LITTLE OR NO
ACCUMULATIONS EXPECTED.
ANOTHER UPPER TROUGH SWEEPS ACROSS NEW MEXICO MONDAY. LIMITED POPS
TO MOSTLY THE MOUNTAINS THOUGH ECMWF BIT FURTHER SOUTH WITH THE PATH
AND THEREFORE ALL AREAS MAY HAVE A CHANCE OF SHOWERS. MAIN UPPER LOW
THEN MOVES SOUTHEAST RIGHT BEHIND THIS TROUGH ON TUESDAY FOR A
CONTINUED CHANCE OF SHOWERS. SNOW LEVELS SHOULD REMAIN AROUND 7000
FT. GFS STILL CUTTING THIS LOW OFF AND RETROGRADING IT BACK TO
WESTERN ARIZONA WEDNESDAY AND THURSDAY WHILE ECMWF KEEPS IT
PROGRESSIVE AND EAST OF THE AREA AFTER TUESDAY. EITHER SOLUTION
LIKELY MEANS MOSTLY DRY AFTER TUESDAY.
TEMPERATURES WILL REMAIN BELOW NORMAL TODAY AND SATURDAY BEFORE
WARMING BACK ABOVE NORMAL SUNDAY AND MONDAY.
&&
.AVIATION...VALID 09/12Z-10/12Z...
CONSIDERABLE CLOUDS WILL PERSIST TODAY ALTHOUGH MAIN BAND OF THICKER
CLOUDS AND AREAS OF RAIN WILL REMAIN MOSTLY NORTH OF A LINE FROM
REDROCK TO HATCH TO ALAMOGORDO. CONDITIONS SOUTH MOSTLY
VFR...CONDITIONS TO THE NORTH OF THIS LINE WILL BE MOSTLY BKN/OVC120
WITH LAYERS TO 300. OCNL -RA BKN090...WITH OCNL CIGS AOB 030 VSBYS
3-5SM -SN ABOVE 7000 FT. WINDS INCREASING TO EAST 15-25 KTS THIS
MORNING AS COLD FRONT MOVES IN. HIGHER GUSTS TO 40 KTS POSSIBLE
ALONG WEST SLOPES OF TERRAIN.
&&
.FIRE WEATHER...
OCCASIONAL RAIN WILL CONTINUE TODAY...MOSTLY OVER THE FIRE ZONES
FROM AND EAST-WEST LINE CENTERED ON HATCH. SOME SNOW IS LIKELY IN
THIS AREA ABOVE 7000 FT. BACK DOOR COLD FRONT WILL BRING EAST WINDS
OF 15 TO 30 MPH LATER THIS MORNING AND AFTERNOON.
AREAS OF LIGHT RAIN WILL CONTINUE SATURDAY AND SATURDAY NIGHT. SNOW
LEVELS WILL START AROUND 7000 FT BUT WILL FALL TO AROUND 4000 FT
LATE SATURDAY NIGHT...WITH PERHAPS A BRIEF MIXTURE OF RAIN/SNOW IN
THE LOWLAND ZONES. ANOTHER SHOT OF SHOWERS IS POSSIBLE
MONDAY/TUESDAY...MOSTLY OVER THE MOUNTAINS...AS ANOTHER UPPER LOW
APPROACHES THE AREA. SNOW LEVELS FOR THIS EVENT MOSTLY AT AROUND
7000 FT. MIN RH`S WILL REMAIN AT AROUND 50-65% TODAY AND SATURDAY
BEFORE LOWERING ABOUT 10 POINTS SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 41 26 47 33 57 / 20 20 10 0 0
SIERRA BLANCA 35 22 44 32 55 / 20 20 20 0 0
LAS CRUCES 41 26 45 32 55 / 20 20 10 0 0
ALAMOGORDO 42 24 47 30 54 / 60 20 10 0 0
CLOUDCROFT 34 19 39 24 44 / 50 20 20 10 0
TRUTH OR CONSEQUENCES 41 26 47 32 54 / 50 20 20 0 0
SILVER CITY 41 28 45 33 52 / 60 20 10 10 0
DEMING 44 27 47 31 56 / 30 20 10 0 0
LORDSBURG 46 28 47 33 56 / 20 20 10 0 0
WEST EL PASO METRO 43 28 47 31 56 / 20 20 10 0 0
DELL CITY 33 23 43 28 56 / 30 20 20 0 0
FORT HANCOCK 42 24 49 31 58 / 20 20 20 0 0
LOMA LINDA 35 24 42 34 53 / 20 20 20 0 0
FABENS 42 24 46 31 57 / 20 20 10 0 0
SANTA TERESA 42 24 47 31 56 / 20 20 10 0 0
WHITE SANDS HQ 41 27 46 34 55 / 40 20 20 0 0
JORNADA RANGE 42 22 47 28 55 / 60 20 20 0 0
HATCH 44 26 48 31 57 / 60 20 10 0 0
COLUMBUS 45 28 45 34 56 / 20 10 10 0 0
OROGRANDE 41 24 46 31 54 / 40 20 20 0 0
MAYHILL 32 20 46 29 50 / 40 20 20 0 0
MESCALERO 32 19 42 27 47 / 40 20 10 10 0
TIMBERON 38 19 43 27 49 / 50 20 20 0 0
WINSTON 41 26 47 32 51 / 40 20 10 10 0
HILLSBORO 41 28 46 34 54 / 60 20 20 10 0
SPACEPORT 42 23 47 29 55 / 60 20 20 0 0
LAKE ROBERTS 40 27 49 32 51 / 60 20 10 20 0
HURLEY 42 28 45 33 54 / 60 20 10 10 0
CLIFF 45 27 47 30 55 / 60 20 10 10 0
MULE CREEK 45 27 45 28 53 / 30 20 10 10 10
FAYWOOD 45 28 45 34 54 / 60 20 10 10 0
ANIMAS 50 29 49 33 59 / 20 20 10 0 0
HACHITA 48 29 47 30 58 / 20 20 10 0 0
ANTELOPE WELLS 49 28 51 32 60 / 20 20 10 0 0
CLOVERDALE 54 28 51 36 59 / 20 20 10 0 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
17 HEFNER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1108 PM CST THU JAN 8 2015
.DISCUSSION...
SEE AVIATION FOR 6Z TAF ISSUANCE.
&&
.AVIATION...
LIGHT PRECIP ACROSS KIAH AND NORTHWARDS THIS EVENING THANKS TO
WEAK UPGLIDE AND UPPER LEVEL DISTURBANCES MOVING OVERHEAD. 850
AND 700 MB MAPS SHOWING TEMPS ABOVE FREEZING WITH AMDAR SOUNDINGS
SHOWING BELOW FREEZING LEVEL BETWEEN 250 FT AND 2600 FT. STILL A
SLIGHT CHANCE OF SOME FROZEN PRECIP AT KCLL/ KUTS/ AND KCXO WHERE
DEWPOINT/ TEMPERATURE SPREADS REMAIN GREATER THAN 10 DEGREES.
THANKS TO SOUTH WIND THIS EVENING TEMPS HAVE REMAINED RELATIVELY
STABLE THOUGH AND TEMPS WILL LIKELY CONTINUE NEAR WHERE THEY
CURRENTLY AREA (MAYBE A DEGREE OR TWO COOLER). KIAH SOUTHWARDS
LOOKS LIKE ALL RAIN TONIGHT INTO TOMORROW. HIGH RES MODELS
CONTINUE TO DEVELOP PRECIP THIS MORNING TO THE SOUTHWEST AND THEN
SLOWLY MOVE THE RAIN OUT OF THE AREA FRIDAY AFTERNOON INTO
EVENING. FORECAST SOUNDINGS FURTHER SUPPORT THESE TRENDS AS
SOUNDINGS LOOSE LOW LEVEL MOISTURE FRIDAY EVENING AS SURFACE HIGH
PRESSURE MOVES FURTHER SOUTH. WINDS WILL ALSO SWITCH FROM THE
NORTH TOMORROW MORNING AS ANOTHER REINFORCING COLD FRONT MOVES
INTO THE AREA. 23
&&
.PREV DISCUSSION... /ISSUED 1024 PM CST THU JAN 8 2015/
DISCUSSION...
WE ARE MONITORING SURFACE OBSERVATIONS THIS EVENING AS AREAS OF LIGHT
RAIN CONTINUE TO MOVE WEST TO EAST ACROSS THE AREA. SO FAR...TEMPERATURES
ARE HOLDING STEADY OR SLOWLY RISING. IF THIS TREND CONTINUES DURING
THE OVERNIGHT HOURS...ONLY RAIN WILL OCCUR. AS OF NOW...IT APPEARS
THAT THE BEST SHOT FOR ANY MIXED PRECIPITATION TO OCCUR WILL BE AFTER
SUNRISE UP NORTH WHEN TEMPERATURES BEGIN TO FALL BEHIND THE NEXT COLD
FRONT. THE CURRENT FORECAST HAS THIS COVERED WELL...SO WILL MAKE NO
CHANGES THIS EVENING AND WAIT FOR ALL OF THE NEW MODELS TO ARRIVE.
42
PREV DISCUSSION... /ISSUED 541 PM CST THU JAN 8 2015/
DISCUSSION...
SEE AVIATION FOR 0Z TAF ISSUANCE.
AVIATION...
AS PREVIOUS DISCUSSION MENTIONED ALREADY STARTING TO GET SOME
REPORTS OF LIGHT DRIZZLE. HIGH RES MODELS ALSO HINTING AT PRECIP
STARTING NORTH OF INTERSTATE 10 BETWEEN MIDNIGHT AND 2AM. FORECAST
SOUNDINGS FROM NAM AND GFS ALSO CONTINUE TO INCREASE MOISTURE
LEVELS OVERNIGHT (PWAT FROM 0.45" TO AROUND 1.02"). GFS ALSO SHOWS
THIS ON ISENTROPIC SURFACES. GIVEN THE ABOVE HAVE INTRODUCED THE
CHANCE OF RAIN EARLIER INTO THE TAFS. BEST CHANCE OF PRECIP LOOKS
TO BE NORTH KIAH NORTHWARDS. THE OTHER QUESTION IS WILL THE PRECIP
BE FROZEN AT ALL. CURRENT FORECAST SOUNDINGS SUPPORT THE
POSSIBILITY OF FROZEN PRECIP AT KUTS AND KCLL FRIDAY MORNING.
DEWPOINTS ARE CURRENTLY IN THE TEENS ACROSS THE AREA WHICH IS
CONCERNING (FOR TEMPS WET BULBING DOWN). WILL CONTINUE TO MONITOR
THE SITUATION AND UPDATE THE TAFS AS NEEDED.
PREV DISCUSSION... /ISSUED 517 PM CST THU JAN 8 2015/
DISCUSSION...
HAVE UPDATE THE FORECAST FOR THE REST OF THIS AFTERNOON AND THIS EVENING
BY ADDING LOW POPS FOR LIGHT RAIN. SOME LIGHT RAIN AND DRIZZLE REPORTS
HAVE BEEN COMING INTO OUR OFFICE...AND SURFACE OBS ARE STARTING TO SHOW
PRECIPITATION TOO. AREA RADARS ARE SHOWING MORE ACTIVITY TRYING TO WORK
THIS WAY FROM THE WEST...BUT THEY ARE FIGHTING T/TD SPREADS OF SOME
15 TO 20 DEGREES.
21Z HRRR AND 18Z TEXAS TECH MODELS ARE BOTH POINTING TOWARD INCREASING
COVERAGE BETWEEN 9 PM AND 3 AM WHEN THE T/TD SPREAD DECREASES. CURRENT
FORECAST HAS INCREASING POPS DURING THIS TIME PERIOD...WITH SOME OF
THE PRECIP BECOMING FROZEN AFTER MIDNIGHT. 42
PREV DISCUSSION... /ISSUED 336 PM CST THU JAN 8 2015/
SMALL THREAT OF WINTER PRECIPITATION FRIDAY MORNING...
DISCUSSION...
SFC RIDGE HAS MOVED EAST OF THE AREA THIS AFTERNOON BUT STILL
LEAVES A COLD/DRY AIRMASS IN PLACE OVER SE TX. VIS SATELLITE SHOWS
CLOUD COVER INCREASING SO TEMPS MAY NOT INCREASE VERY MUCH THE
REST OF THE DAY. MAX TEMPS MAY HAVE REACHED LOW 40S IF THAT WITH
ARCTIC AIRMASS IN PLACE. U.S. SFC ANALYSIS HAS COLD FRONT PUSHING
THROUGH THE C PLAINS WITH 1046MB HIGH OVER CANADA INTO MONTANA.
THIS FRONT SHOULD REACH THE AREA BY FRI MORNING.
ALOFT 12Z 500MB ANALYSIS HAS MAINLY NW FLOW OVER THE GULF GIVEN
DEEP HUDSON BAY LOW AND BROAD TROUGH OVER MUCH OF THE EASTERN U.S.
WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH ROTATING THROUGH THE
FLOW ACROSS THE N PLAINS WHICH IS HELPING PUSH COLD FRONT
SOUTHWARD TODAY. WATER VAPOR IMAGERY ALSO SHOWS AN UPPER LOW OVER
BAJA PENINSULA WHICH SHOULD SLOWLY MOVE ACROSS MEXICO INTO TX BY
SAT NIGHT AND SUN.
FRI MORNING WINTER PRECIP...MODELS STILL IN GOOD AGREEMENT WITH
COLD FRONT REACHING COLLEGE STATION TO LUFKIN BY 12-15Z FRI. WITH
THIS BOUNDARY LOW LEVEL FRONTOGENESIS DEVELOPS ACROSS THIS AREA
BEGINNING IN C TX... STRETCHING FROM BWD TOWARDS LFK. OMEGA ALSO
LOOKS TO SPIKE DURING THIS TIME IN RESPONSE. ISENTROPIC LIFT AT
290K SFC ALSO SHOWS SOME SLIGHT LIFT WITH MOISTURE ARRIVING FROM
THE W/SW. ALL FORCING LOOKS TO BE RATHER MESOSCALE AND DEPEND ON
THE BOUNDARY. RIGHT NOW SFC DEWPOINTS ARE IN THE TEENS TO SINGLE
DIGITS BUT MODELS ALL SHOW RAPID MOISTENING OVERNIGHT. LOOKING AT
SEVERAL NAM/GFS BUFR SOUNDINGS...LOW/MID LEVELS DO SATURATE WITH
ISENTROPIC LIFT OVER FRONTAL BOUNDARY BUT LOW LEVELS STILL LOOK
DRY. PRECIP MAY BEGIN TO FALL OVER THE REGION 06Z-12Z FRI BUT
LIKELY EVAPORATE. THIS BRINGS ANOTHER FACTOR INTO FORECASTING
WINTER PRECIP...WILL THERMODYNAMIC WET BULBING BE ENOUGH WITH
INCREASING LIFT TO DECREASE TEMP PROFILES AND MOISTEN THE
ATMOSPHERE TO SUPPORT FROZEN PRECIP? THATS A BIG QUESTION AND ONE
WHICH THE FORECAST HINGES UPON. RIGHT NOW CONFIDENCE IS ONLY HIGH
ENOUGH TO KEEP A MENTION OF RA/FZRA IN FORECAST. MODEL SOUNDINGS
DO SHOW COLD SUB-FREEZING LAYER DEEPENING AS COLD FRONT MOVES
THROUGH SO COULD SEE A TRANSITION TO SLEET. RIGHT NOW THE FORECAST
WILL KEEP RA/FZRA AND NOT CONFUSE THINGS WITH ANOTHER PRECIP TYPE
THAT HAS A LESS LIKELY CHANCE OF DEVELOPING.
SO IF ALL THESE FACTORS COME TOGETHER...THERE COULD BE SOME
BANDED PRECIP WITH HIGHER PRECIP AMOUNTS THAN FORECAST. THAT IS A
WORSE CASE SCENARIO. REALISTICALLY IT LOOKS LIKE AREAS FROM NORTH
OF BRENHAM...CONROE...CLEVELAND LINE COULD SEE A LITTLE ICE ON
TREES BUT LITTLE/NO ACCUMULATION. HIGHER ACCUMULATIONS ARE MORE
LIKELY FOR THE MADISONVILLE/CROCKETT/TRINITY AREAS WHERE SFC TEMPS
SHOULD BE COLDER TO SUPPORT FZRA BUT MAY HAVE ISSUES MOISTENING
ENOUGH FOR PRECIP INITIALLY. LIKELY TIME FRAME LOOKS TO BE
PLUS/MINUS 3 HRS OF 15Z SO FRI 12-18Z OR 6AM TO NOON. NO ADVISORY
WILL BE ISSUED AT THIS TIME SINCE ACCUMULATIONS WILL BE LIGHT BUT
THAT COULD CHANGE IF BANDING OF PRECIP OCCURS AND IT BECOMES MORE
LIKELY ICE ACCUMULATIONS DEVELOP. BIGGEST IMPACTS WILL BE ICING OF
BRIDGES AND OVERPASSES OR ANY ELEVATED SURFACE.
THERE LOOKS TO BE A LULL IN PRECIP FRI NIGHT AS UPPER LOW OVER
MEXICO MOVES INTO TX ON SAT/SUN. TEMPS WILL AGAIN BE NEAR FREEZING
OR JUST BELOW FREEZING SAT MORNING BUT PRECIP MAY START MORE OVER
C TX AND MOVE INTO THE AREA. THERE IS A SMALL CHANCE OF FZRA AGAIN
FOR WESTERN AREAS OF BURLESON/WASHINGTON COUNTIES BUT DRIER AIR AT
925MB MAY KEEP PRECIP FROM REACHING THE GROUND. LATER IN THE
MORNING WARM ADVECTION GREATLY INCREASES SO EXPECT RAIN AS PRECIP
TYPE. LOOK FOR RAIN TO CONTINUE SUN AS SYSTEM MOVES EAST. RAINFALL
TOTALS THROUGH 00Z MON LOOK TO BE AROUND A HALF INCH AREA WIDE. AS
THIS UPPER LEVEL TROUGH MOVES EAST ANOTHER COLD FRONT WILL PUSH
THROUGH MON/MON NIGHT.
IN THE EXTENDED FORECAST IT LOOKS LIKE ANOTHER UPPER LEVEL SYSTEM
MOVES INTO TX TUE/WED SO HAVE INCREASING RAIN CHANCES FOR MID
WEEK. THIS SYSTEM SHOULD QUICKLY MOVE EAST WED/THUR WITH HIGH
PRESSURE BUILDING OVER THE AREA WED NIGHT INTO THUR. THIS SHOULD
ALLOW FOR DRY CANADIAN AIRMASS TO END PRECIP CHANCES THROUGH THE
END OF THE WEEK.
39
MARINE...
NO ADVISORIES/FLAGS FOR TONIGHT/EARLY FRI AS WINDS/SEAS HAVE FINALLY
CALMED DOWN THIS AFTN. HOWEVER STILL EXPECTING CONDITIONS TO RAMP UP
ONCE AGAIN (AT LEAST FOR THE COASTAL WATERS) BY FRI NIGHT AS THE PRE-
SSURE GRADIENT TIGHTENS IN RESPONSE TO AN APPROACHING UPPER LEVEL WX
SYSTEM FROM THE WEST. WILL ALSO HAVE TO KEEP AN EYE ON THINGS REMAIN-
ING UNSETTLED THROUGH THE WEEKEND AS A COASTAL LOW DEVELOPS NEAR THE
LOWER TX COAST AND MOVES UP IN THIS DIRECTION. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 38 32 38 29 39 / 20 40 50 20 40
HOUSTON (IAH) 42 34 40 33 40 / 20 40 40 20 40
GALVESTON (GLS) 38 38 45 39 46 / 20 30 50 30 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM 9 AM CST FRIDAY THROUGH
FRIDAY AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY FROM 9 AM TO 6 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...42
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1024 PM CST THU JAN 8 2015
.DISCUSSION...
WE ARE MONITORING SURFACE OBSERVATIONS THIS EVENING AS AREAS OF LIGHT
RAIN CONTINUE TO MOVE WEST TO EAST ACROSS THE AREA. SO FAR...TEMPERATURES
ARE HOLDING STEADY OR SLOWLY RISING. IF THIS TREND CONTINUES DURING
THE OVERNIGHT HOURS...ONLY RAIN WILL OCCUR. AS OF NOW...IT APPEARS
THAT THE BEST SHOT FOR ANY MIXED PRECIPITATION TO OCCUR WILL BE AFTER
SUNRISE UP NORTH WHEN TEMPERATURES BEGIN TO FALL BEHIND THE NEXT COLD
FRONT. THE CURRENT FORECAST HAS THIS COVERED WELL...SO WILL MAKE NO
CHANGES THIS EVENING AND WAIT FOR ALL OF THE NEW MODELS TO ARRIVE.
42
&&
.PREV DISCUSSION... /ISSUED 541 PM CST THU JAN 8 2015/
DISCUSSION...
SEE AVIATION FOR 0Z TAF ISSUANCE.
AVIATION...
AS PREVIOUS DISCUSSION MENTIONED ALREADY STARTING TO GET SOME
REPORTS OF LIGHT DRIZZLE. HIGH RES MODELS ALSO HINTING AT PRECIP
STARTING NORTH OF INTERSTATE 10 BETWEEN MIDNIGHT AND 2AM. FORECAST
SOUNDINGS FROM NAM AND GFS ALSO CONTINUE TO INCREASE MOISTURE
LEVELS OVERNIGHT (PWAT FROM 0.45" TO AROUND 1.02"). GFS ALSO SHOWS
THIS ON ISENTROPIC SURFACES. GIVEN THE ABOVE HAVE INTRODUCED THE
CHANCE OF RAIN EARLIER INTO THE TAFS. BEST CHANCE OF PRECIP LOOKS
TO BE NORTH KIAH NORTHWARDS. THE OTHER QUESTION IS WILL THE PRECIP
BE FROZEN AT ALL. CURRENT FORECAST SOUNDINGS SUPPORT THE
POSSIBILITY OF FROZEN PRECIP AT KUTS AND KCLL FRIDAY MORNING.
DEWPOINTS ARE CURRENTLY IN THE TEENS ACROSS THE AREA WHICH IS
CONCERNING (FOR TEMPS WET BULBING DOWN). WILL CONTINUE TO MONITOR
THE SITUATION AND UPDATE THE TAFS AS NEEDED.
PREV DISCUSSION... /ISSUED 517 PM CST THU JAN 8 2015/
DISCUSSION...
HAVE UPDATE THE FORECAST FOR THE REST OF THIS AFTERNOON AND THIS EVENING
BY ADDING LOW POPS FOR LIGHT RAIN. SOME LIGHT RAIN AND DRIZZLE REPORTS
HAVE BEEN COMING INTO OUR OFFICE...AND SURFACE OBS ARE STARTING TO SHOW
PRECIPITATION TOO. AREA RADARS ARE SHOWING MORE ACTIVITY TRYING TO WORK
THIS WAY FROM THE WEST...BUT THEY ARE FIGHTING T/TD SPREADS OF SOME
15 TO 20 DEGREES.
21Z HRRR AND 18Z TEXAS TECH MODELS ARE BOTH POINTING TOWARD INCREASING
COVERAGE BETWEEN 9 PM AND 3 AM WHEN THE T/TD SPREAD DECREASES. CURRENT
FORECAST HAS INCREASING POPS DURING THIS TIME PERIOD...WITH SOME OF
THE PRECIP BECOMING FROZEN AFTER MIDNIGHT. 42
PREV DISCUSSION... /ISSUED 336 PM CST THU JAN 8 2015/
SMALL THREAT OF WINTER PRECIPITATION FRIDAY MORNING...
DISCUSSION...
SFC RIDGE HAS MOVED EAST OF THE AREA THIS AFTERNOON BUT STILL
LEAVES A COLD/DRY AIRMASS IN PLACE OVER SE TX. VIS SATELLITE SHOWS
CLOUD COVER INCREASING SO TEMPS MAY NOT INCREASE VERY MUCH THE
REST OF THE DAY. MAX TEMPS MAY HAVE REACHED LOW 40S IF THAT WITH
ARCTIC AIRMASS IN PLACE. U.S. SFC ANALYSIS HAS COLD FRONT PUSHING
THROUGH THE C PLAINS WITH 1046MB HIGH OVER CANADA INTO MONTANA.
THIS FRONT SHOULD REACH THE AREA BY FRI MORNING.
ALOFT 12Z 500MB ANALYSIS HAS MAINLY NW FLOW OVER THE GULF GIVEN
DEEP HUDSON BAY LOW AND BROAD TROUGH OVER MUCH OF THE EASTERN U.S.
WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH ROTATING THROUGH THE
FLOW ACROSS THE N PLAINS WHICH IS HELPING PUSH COLD FRONT
SOUTHWARD TODAY. WATER VAPOR IMAGERY ALSO SHOWS AN UPPER LOW OVER
BAJA PENINSULA WHICH SHOULD SLOWLY MOVE ACROSS MEXICO INTO TX BY
SAT NIGHT AND SUN.
FRI MORNING WINTER PRECIP...MODELS STILL IN GOOD AGREEMENT WITH
COLD FRONT REACHING COLLEGE STATION TO LUFKIN BY 12-15Z FRI. WITH
THIS BOUNDARY LOW LEVEL FRONTOGENESIS DEVELOPS ACROSS THIS AREA
BEGINNING IN C TX... STRETCHING FROM BWD TOWARDS LFK. OMEGA ALSO
LOOKS TO SPIKE DURING THIS TIME IN RESPONSE. ISENTROPIC LIFT AT
290K SFC ALSO SHOWS SOME SLIGHT LIFT WITH MOISTURE ARRIVING FROM
THE W/SW. ALL FORCING LOOKS TO BE RATHER MESOSCALE AND DEPEND ON
THE BOUNDARY. RIGHT NOW SFC DEWPOINTS ARE IN THE TEENS TO SINGLE
DIGITS BUT MODELS ALL SHOW RAPID MOISTENING OVERNIGHT. LOOKING AT
SEVERAL NAM/GFS BUFR SOUNDINGS...LOW/MID LEVELS DO SATURATE WITH
ISENTROPIC LIFT OVER FRONTAL BOUNDARY BUT LOW LEVELS STILL LOOK
DRY. PRECIP MAY BEGIN TO FALL OVER THE REGION 06Z-12Z FRI BUT
LIKELY EVAPORATE. THIS BRINGS ANOTHER FACTOR INTO FORECASTING
WINTER PRECIP...WILL THERMODYNAMIC WET BULBING BE ENOUGH WITH
INCREASING LIFT TO DECREASE TEMP PROFILES AND MOISTEN THE
ATMOSPHERE TO SUPPORT FROZEN PRECIP? THATS A BIG QUESTION AND ONE
WHICH THE FORECAST HINGES UPON. RIGHT NOW CONFIDENCE IS ONLY HIGH
ENOUGH TO KEEP A MENTION OF RA/FZRA IN FORECAST. MODEL SOUNDINGS
DO SHOW COLD SUB-FREEZING LAYER DEEPENING AS COLD FRONT MOVES
THROUGH SO COULD SEE A TRANSITION TO SLEET. RIGHT NOW THE FORECAST
WILL KEEP RA/FZRA AND NOT CONFUSE THINGS WITH ANOTHER PRECIP TYPE
THAT HAS A LESS LIKELY CHANCE OF DEVELOPING.
SO IF ALL THESE FACTORS COME TOGETHER...THERE COULD BE SOME
BANDED PRECIP WITH HIGHER PRECIP AMOUNTS THAN FORECAST. THAT IS A
WORSE CASE SCENARIO. REALISTICALLY IT LOOKS LIKE AREAS FROM NORTH
OF BRENHAM...CONROE...CLEVELAND LINE COULD SEE A LITTLE ICE ON
TREES BUT LITTLE/NO ACCUMULATION. HIGHER ACCUMULATIONS ARE MORE
LIKELY FOR THE MADISONVILLE/CROCKETT/TRINITY AREAS WHERE SFC TEMPS
SHOULD BE COLDER TO SUPPORT FZRA BUT MAY HAVE ISSUES MOISTENING
ENOUGH FOR PRECIP INITIALLY. LIKELY TIME FRAME LOOKS TO BE
PLUS/MINUS 3 HRS OF 15Z SO FRI 12-18Z OR 6AM TO NOON. NO ADVISORY
WILL BE ISSUED AT THIS TIME SINCE ACCUMULATIONS WILL BE LIGHT BUT
THAT COULD CHANGE IF BANDING OF PRECIP OCCURS AND IT BECOMES MORE
LIKELY ICE ACCUMULATIONS DEVELOP. BIGGEST IMPACTS WILL BE ICING OF
BRIDGES AND OVERPASSES OR ANY ELEVATED SURFACE.
THERE LOOKS TO BE A LULL IN PRECIP FRI NIGHT AS UPPER LOW OVER
MEXICO MOVES INTO TX ON SAT/SUN. TEMPS WILL AGAIN BE NEAR FREEZING
OR JUST BELOW FREEZING SAT MORNING BUT PRECIP MAY START MORE OVER
C TX AND MOVE INTO THE AREA. THERE IS A SMALL CHANCE OF FZRA AGAIN
FOR WESTERN AREAS OF BURLESON/WASHINGTON COUNTIES BUT DRIER AIR AT
925MB MAY KEEP PRECIP FROM REACHING THE GROUND. LATER IN THE
MORNING WARM ADVECTION GREATLY INCREASES SO EXPECT RAIN AS PRECIP
TYPE. LOOK FOR RAIN TO CONTINUE SUN AS SYSTEM MOVES EAST. RAINFALL
TOTALS THROUGH 00Z MON LOOK TO BE AROUND A HALF INCH AREA WIDE. AS
THIS UPPER LEVEL TROUGH MOVES EAST ANOTHER COLD FRONT WILL PUSH
THROUGH MON/MON NIGHT.
IN THE EXTENDED FORECAST IT LOOKS LIKE ANOTHER UPPER LEVEL SYSTEM
MOVES INTO TX TUE/WED SO HAVE INCREASING RAIN CHANCES FOR MID
WEEK. THIS SYSTEM SHOULD QUICKLY MOVE EAST WED/THUR WITH HIGH
PRESSURE BUILDING OVER THE AREA WED NIGHT INTO THUR. THIS SHOULD
ALLOW FOR DRY CANADIAN AIRMASS TO END PRECIP CHANCES THROUGH THE
END OF THE WEEK.
39
MARINE...
NO ADVISORIES/FLAGS FOR TONIGHT/EARLY FRI AS WINDS/SEAS HAVE FINALLY
CALMED DOWN THIS AFTN. HOWEVER STILL EXPECTING CONDITIONS TO RAMP UP
ONCE AGAIN (AT LEAST FOR THE COASTAL WATERS) BY FRI NIGHT AS THE PRE-
SSURE GRADIENT TIGHTENS IN RESPONSE TO AN APPROACHING UPPER LEVEL WX
SYSTEM FROM THE WEST. WILL ALSO HAVE TO KEEP AN EYE ON THINGS REMAIN-
ING UNSETTLED THROUGH THE WEEKEND AS A COASTAL LOW DEVELOPS NEAR THE
LOWER TX COAST AND MOVES UP IN THIS DIRECTION. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 32 38 29 39 34 / 40 50 20 40 50
HOUSTON (IAH) 34 40 33 40 37 / 40 40 20 40 60
GALVESTON (GLS) 38 45 39 46 45 / 30 50 30 50 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION FROM 9 AM CST FRIDAY THROUGH
FRIDAY AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY FROM 9 AM TO 6 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...42
AVIATION/MARINE...23
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
152 AM EST FRI JAN 9 2015
.SYNOPSIS...
ARCTIC AIR WILL MOVE OUT OF THE AREA TONIGHT AS HIGH PRESSURE
MOVES OFF THE SOUTHEAST COAST. A LOW PRESSURE SYSTEM OVER THE
UPPER MISSISSIPPI VALLEY WILL MOVE EAST TONIGHT AND PUSH A COLD
FRONT THROUGH THE REGION ON FRIDAY. STRONG HIGH PRESSURE BEHIND
THE FRONT WILL BRING ANOTHER ROUND OF GUSTY WINDS AND ARCTIC AIR
FRIDAY NIGHT AND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM EST FRIDAY...
UPDATED TO ISSUE A WIND ADVISORY FOR MOST LOCATIONS ALONG AND WEST
OF THE BLUE RIDGE FOR STRONG SW WINDS OCCURRING AHEAD OF THE FRONT
AND ALSO WITH THE LIKELY SURGE IN WEST WINDS WITH THE FROPA DURING
THE MORNING. THIS MAINLY FOR THE RIDGES GIVEN THE 50-60 KT JET MAX
SLIDING OVER THE INVERSION THAT REMAINS BUT LIKELY TO GIVE WAY
WITH ONGOING WARM ADVECTION ALOFT ATTM. THINK BEST GUSTS FROM
ABOUT 09Z THROUGH LATE MORNING AS SUPPORTED BY THE LATEST HRRR AND
RNK-WRF WIND FIELDS.
PREVIOUS DISCUSSION AT 400 PM...
SURFACE HIGH PRESSURE HAD MOVED SOUTHEAST INTO THE CAROLINAS AND
LOWER MISSISSIPPI VALLEY. THIS HIGH WILL CONTINUE TO MOVE OFFSHORE
TONIGHT. WINDS HAD DIMINISHED AND WILL BE LIGHT THIS EVENING. WITH A
DRY AIR MASS AND SURFACE DEW POINTS JUST BELOW ZERO...EXPECTING A
SHARP DROP IN TEMPERATURE DURING THE EVENING...ESPECIALLY IN THE
SHELTERED VALLEYS. AS CLOUDS INCREASE AND WINDS PICK UP FROM THE
SOUTHWEST OVERNIGHT...TEMPERATURES WILL RISE...PARTICULARLY ON THE
RIDGES. BUFKIT SUGGESTS INVERSION MAY LIFT ENOUGH THAT HIGHER
ELEVATIONS WEST OF THE BLUE RIDGE COULD HAVE WIND GUSTS CLOSE TO 40
MPH AROUND 12Z/7AM.
LOW PRESSURE WAS OVER MINNESOTA WITH A COLD FRONT TRAILING INTO
MONTANA. THIS FRONT CROSSES THROUGH THE FORECAST AREA ON FRIDAY. 850
MB START AROUND -4 AT 00Z/7PM THIS EVENING...THEN BEHIND THE FRONT
ON FRIDAY...MORE ARCTIC AIR SURGES IN AND TEMPERATURES DROP BACK TO
-10 TO -15. GUSTY WINDS WILL AGAIN FOLLOW THE FRONT.
AMOUNT OF MOISTURE ALONG AND BEHIND THE FRONT IS LIMITED. BUFKIT
SHOWED A LAYER AROUND 2000 FEET DEEP...RIGHT AT THE PRIME SNOW
GROWTH TEMPERATURES. WILL KEEP IN SCATTERED SNOW SHOWERS FROM
BLUEFIELD NORTH ON FAR WESTERN SLOPES. HAVE ADDED BLOWING SNOW IN
WHERE SCATTERED SNOW SHOWERS ARE FORECAST.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
AS OF 250 PM EST THURSDAY...
A 1040MB HIGH PRESSURE SYSTEM WILL TRACK SOUTH ACROSS THE PLAIN
STATES FRIDAY THEN MOVES EAST OVER THE OHIO VALLEY FRIDAY
NIGHT...COMING OVER THE APPALACHIANS SATURDAY MORNING. BEHIND THE
FRONTAL PASSAGE FRIDAY...A TIGHTENING PRESSURE GRADIENT AND MODERATE
PRESSURE RISES (6MB/6HRS) WILL BRING WINDY AND GUSTY CONDITIONS TO
THE AREA THROUGH EARLY SATURDAY MORNING...THEN SUBSIDES AS HIGH
PRESSURE BUILDS ACROSS THE REGION. TEMPERATURES NOT AS COLD ALOFT
(850 MB) FRIDAY NIGHT AS THEY WERE WITH THE PREVIOUS FRONT...RANGING
FROM -5C OVER THE NC/VA BORDER TO -15C OVER THE GREENBRIER VALLEY
AND ALLEGHANY HIGHLANDS. THIS MORNING SOUNDINGS BEHIND THE ARCTIC
FRONT HAD 85H TEMPERATURES -20C AT RNK AND -11C AT GSO. SO NOT AS
COLD SATURDAY MORNING WITH LOWS ACROSS THE MOUNTAINS RANGING FROM 5F
TO 10F ABOVE ZERO TO THE MIDDLE TEENS IN THE EAST. WIND CHILLS
SATURDAY MORNING WILL RANGE FROM 0F TO 10F BELOW WITH HIGHER
ELEVATION PUSHING 20F BELOW. ALSO FOR FRIDAY NIGHT...NORTHWEST FLOW
AND A BRIEF PERIOD WITH TRAJECTORIES FROM THE GREAT LAKES SHOULD
BRING ACCUMULATING DRY SNOW ALONG WESTERN SLOPES OF SOUTHEAST WEST
VIRGINIA. SIMILAR TO YESTERDAYS ARCTIC FRONT...MODELS ARE MOSTLY DRY
WITH THIS FRONT AND ALMOST NOTHING WITH UPSLOPE. FOR NOW...WE WILL
CONTINUE TO ADVERTISE CHANCE POPS ALONG WESTERN SLOPES INTO EARLY
SATURDAY WITH AN INCH OR TWO OF DRY SNOW...SCATTERED MOUNTAIN
FLURRIES ELSEWHERE.
DRY HIGH PRESSURE LINGERS OVER THE MID ATLANTIC SATURDAY AND BECOMES
A 1040MB HYBRID WEDGE SATURDAY NIGHT AND SUNDAY. AN UPPER LEVEL
TROUGH COMING OUT OF THE ROCKIES SATURDAY NIGHT WILL GENERATE AND
TRACK A SERIES OF DISTURBANCES OUT OF THE GULF AND OVER THIS WEDGE
STARTING SUNDAY. WITH SUCH A DRY WEDGE TO BEGIN WITH...ONLY
EXPECTING AN INCREASE IN MID AND HIGH CLOUDS SUNDAY. IF
PRECIPITATION DOES ENTER EARLY...IT LOOKS TO FALL AS A COLD RAIN
OVER CAROLINA LATE IN THE AFTERNOON. MOST OF THE PRECIPITATION
SHOULD HOLD OFF UNTIL SUNDAY NIGHT.
THE HYBRID WEDGE WILL KEEP THE AREA COOL WITH SATURDAYS HIGHS IN THE
M/U 20S ACROSS THE WEST TO THE LOWER 30S EAST. GOOD RADIATIONAL
COOLING POSSIBLE SATURDAY NIGHT WITH COLD LOWS RANGING FROM 10F TO
20F ABOVE ZERO. SUNDAYS TEMPERATURES WILL WARM INTO THE UPPER 30S TO
LOWER 40S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM EST THURSDAY...
THIS PERIOD OF THE FORECAST HAS THE POTENTIAL TO BE ON THE WET SIDE
FOR MOST OF IT...AND ALSO OFFER ITSELF TO A WINTRY MIX OF
PRECIPITATION...ESPECIALLY OVER THE NORTHERN HALF OF THE REGION.
FROM SUNDAY NIGHT THROUGH WEDNESDAY NIGHT THE OVERALL SYNOPTIC
PATTERN WILL BE ONE OF AN UPPER TROUGH ACROSS CENTRAL CONUS THAT
WILL GRADUALLY MAKE ITS WAY TO THE EAST COAST. ON THE EAST SIDE OF
THIS TROUGH...A SOUTHWESTERLY JET WILL ADVECT A SERIES OF SHORTWAVE
TROUGHS OVER...OR NEAR...OUR REGION ALONG WITH ACCOMPANYING MOISTURE
WITH GULF OF MEXICO ORIGINS. JUST HOW MUCH PROGRESSION EASTWARD THE
UPPER TROUGH MAKES...AND HOW QUICKLY...WILL PLAY A BIG ROLE IN JUST
HOW MANY OF THESE FEATURE MOVE OVER THE REGION...BARELY SKIRT
IT...OR MISS IT COMPLETELY OFF THE EAST COAST...ALL WHILE OUR
WEATHER TURNS DRIER AND COLDER INSTEAD.
THE PAST SEVERAL DAYS OUR FORECAST HAS GIVEN GREATER WEIGHT TO THE
CANADIAN/ECMWF SOLUTIONS THAT HAVE HAD A SLOWER PROGRESSION EASTWARD
OF THE UPPER TROUGH THAN THAT OF THE QUICKER GFS. BOTH THE ECMWF AND
CANADIAN HAVE ALSO HAD LOW LEVEL THERMAL PROFILES THAT FAVOR SLEET
OR FREEZING RAIN FOR A WINTRY PRECIPITATION TYPE OVER THAT OF SNOW.
ALSO..THESE SOLUTIONS HAVE HAD VERY LIMITED...IF ANY...BREAK IN THE
PRECIPITATION BETWEEN THE VARIOUS SHORTWAVE TROUGHS AS THEY PROGRESS
NORTHEAST OVER OR NEAR THE REGION. THE 12Z/7AM GUIDANCE AMONG THE
VARIOUS MODELS SHOWS THE ECMWF SOLUTION MORE IN LINE WITH THE
GFS...WITH THE CANADIAN STILL COMPARABLE TO ITS EARLIER
COUNTERPARTS. THIS TREND...IN AT LEAST THE ECMWF...CAUSES SOME
HESITATION IN NOT HAVING ANY NOTABLE ADJUSTMENTS TO OUR FORECAST
DURING THIS TIMEFRAME. THE ECMWF BEING MORE PROGRESSIVE ALSO ALLOWS
COLDER AIR TO WORK ITS WAY INTO THE REGION...COMPARABLE TO THE GFS
OF THE CURRENT AND EARLIER RUNS...AND ALSO ALLOWS FOR A GREATER
DEFINED BREAK IN THE PRECIPITATION IN THE TUESDAY INTO WEDNESDAY
TIMEFRAME...AGAIN MORE IN LINE WITH THE GFS.
OUR FORECAST TODAY FOR THIS TIME PERIOD OF THE FORECAST WILL OFFER A
COMPROMISE OF THESE TRENDS. IT WILL CONTINUE TO FAVOR PROGRESSIVE
SHORTWAVE TROUGHS THROUGH THE REGION WITH LIMITED BREAKS IN THE
ACTIVITY...BUT WILL PLACE GREATER WEIGHT ON A COLDER LOW LEVEL
TEMPERATURE PROFILE.
LINGERING COLD POOL OF SUB-FREEZING SURFACE CONDITIONS WILL STILL BE
ENTRENCHED ACROSS PORTIONS OF THE AREA EARLY SUNDAY EVENING. AS THE
NIGHT PROGRESSES SOUTHWESTERLY WINDS INCREASE AND ALLOW FOR WARM AIR
ADVECTION AT ALL LEVELS...INCLUDING THE SURFACE. EXPECT THE LOW
TEMPERATURE TO OCCUR DURING THE EVENING WITH RISING TEMPERATURES
THEREAFTER. PRECIPITATION IS EXPECTED TO OVERSPREAD THE REGION
DURING THE OVERNIGHT HOURS FROM SOUTHWEST TO NORTHEAST. WHILE
POCKETS OF BOTH FREEZING RAIN AND SLEET ARE PROBABLE WHERE SURFACE
OR NEAR SURFACE CONDITIONS AS COLD ENOUGH...OUR FORECAST WILL
CONTINUE TO REFLECT A RAIN VERSUS FREEZING RAIN FORECAST SUNDAY
NIGHT INTO EARLY MONDAY MORNING FOR SIMPLICITY...AND TO SATISFY OUR
LOCAL DAY 4 AND ONWARD RULE OF NO SLEET IN THE FORECAST IN THAT TIME
RANGE.
ONCE WE GET INTO TUESDAY NIGHT AND BEYOND...OUR FORECAST WILL NOW
REFLECT A COLDER LOW LEVEL THERMAL PROFILE AND HAVE A RAIN VERSUS
SNOW FORECAST. GRANTED...THERE LIKELY WILL BE SOME AMOUNT OF WARM
NOSE ACROSS SOUTHERN PARTS OF THE AREA WHERE SLEET OR FREEING RAIN
WOULD BE MORE LIKELY. HOWEVER...A RAIN VERSUS SNOW FORECAST ALSO
SATISFIES THE OTHER LOCAL RULE OF NO MORE THAN ONE WINTRY
PRECIPITATION TYPE FROM DAY 4 AND ONWARD IN THE FORECAST.
THE BACK EDGE OF THE MAIN UPPER TROUGH IS PROGGED TO EXIT THE REGION
TO THE EAST WEDNESDAY NIGHT INTO THURSDAY. OUR FORECAST WILL REFLECT
THIS WITH DECREASING COVERAGE OF LIGHT RAIN AND LIGHT SNOW. BY
THURSDAY AFTERNOON...LITTLE IF ANY PRECIPITATION WILL BE LEFT ACROSS
THE REGION WITH MORE SUN THAN CLOUDS.
TEMPERATURES DURING THIS PORTION OF THE FORECAST ARE EXPECTED TO BE
AT OR ABOVE NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 1130 PM EST THURSDAY...
VFR CIGS WILL CONTINUE ACROSS THE REGION THIS MORNING MAINLY OF
10-15KFT FALLING TOWARD 4-6KFT IN THE MTNS BY DAWN AS FRONTAL
BOUNDARY MOVES ACROSS. LOOKING FOR SKIES TO SCATTER OUT AND CLEAR
EAST OF THE APPALACHIANS BY MIDDAY WITH GUSTY WINDS FROM THE WEST.
MEANWHILE...CLOUDS WILL STAY BANKED UP INTO THE EARLY AFTERNOON
BEFORE CLEARING AT BLF/LWB.
STILL THINK ENOUGH STRONG WINDS ABOVE WEAK SFC INVERSION TO ALLOW
FOR LOW LVL WIND SHEAR AT ALL SITES THROUGH DAWN BEFORE MIXING
TAKES PLACE AND CORE OF LLJ LIFTS OUT.
EXTENDED AVIATION DISCUSSION...
A SOUTHERN STREAM DISTURBANCE COULD BRING A RETURN TO MVFR CIGS
AND POSSIBLE WINTRY PCPN AND/OR RAIN TO SOME AREAS BY LATE SUN
NIGHT AND MONDAY.
TUESDAY...SOME MODELS SHOWING ANOTHER LOW MAY BE FOLLOWING
MONDAY`S SYSTEM AND PROLONGING THE THREAT OF SUB-VFR CONDITIONS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR VAZ007-009>015-
018>020-022>024.
NC...NONE.
WV...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/JH/WP
SHORT TERM...RCS
LONG TERM...DS
AVIATION...AMS/JH/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
933 PM CST SAT JAN 10 2015
.UPDATE...
ISSUED AT 933 PM CST SAT JAN 10 2015
TEMPERATURES HAVE BEEN PROBLEMATIC THIS EVENING AS THEY HAVE
ACTUALLY RISEN THROUGH THE EVENING AHEAD OF A WEAK COLD FRONT
TRACKING EAST THROUGH NORTH CENTRAL WISCONSIN ON DOWN TO CENTRAL
IOWA. TEMPS ARE IN THE UPPER TEENS TO LOW 20S AHEAD OF THE FRONT
WHERE SOME 3-5KFT STRATUS IS HELPING TO KEEP THOSE TEMPERATURES
UP. SKIES CLEAR OUT ONCE THE FRONT COMES THROUGH AND THE
TEMPERATURES DROP INTO THE SINGLE DIGITS. 11.02Z RAP LOW LEVEL
MOISTURE FIELDS SHOW THIS AREA OF LOWER CLOUDS SHIFTING EAST OF
THE AREA SHORTLY AFTER MIDNIGHT. SO...LOW TEMPERATURES STILL
SHOULD BE HIT OVERNIGHT...IT JUST MAY TAKE A LITTLE LONGER TO GET
DOWN THERE.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 209 PM CST SAT JAN 10 2015
NORTHWEST FLOW ALOFT CONTINUES ACROSS THE REGION PER LATEST WATER
VAPOR/500 MB RAP ANALYSIS. A WEAK MID-LEVEL WAVE/SURFACE TROUGH
WITHIN THIS FLOW WAS DROPPING INTO THE DAKOTAS/MN THIS AFTERNOON
WITH DECENT WING OF 285-290K ISENTROPIC LIFT/WAA OUT AHEAD OF IT
INTO OUR AREA. THIS HAS RESULTED IN WIDESPREAD EXPANSION OF
ALTOCUMULUS/STRATOCUMULUS THROUGH THE DAY. NO SNOW FLURRY ACTIVITY
YET PER SURFACE OBSERVATIONS...BUT RADAR PICKING UP ON VIRGA AROUND
3KFT...SO EXPECTING AT LEAST A FEW FLURRIES GOING THROUGH THE REST
OF THIS AFTERNOON. OTHERWISE...TEMPERATURES ACROSS THE AREA THIS
AFTERNOON WERE IN THE SINGLE DIGITS/TEENS ABOVE ZERO.
LOOK FOR THE MID-LEVEL WAVE/SURFACE TROUGH TO CONTINUE SLIPPING
SOUTHEAST INTO THE REGION THIS EVENING...AND THEN EAST OF THE AREA
AROUND MIDNIGHT. WILL KEEP MENTION OF FLURRIES IN THROUGH THE
EVENING HOURS...MAINLY NORTHEAST OF I-94 BUT THEN DROPPED THEM AFTER
MIDNIGHT WITH FORCING EXITING THE AREA. OTHERWISE...LOOKS LIKE
SUBSTANTIAL MID-LEVEL CLOUD COVER WILL LINGER THROUGH THE OVERNIGHT
HOURS. AS A RESULT...TEMPERATURES ONLY EXPECTED TO DROP INTO THE
SINGLE DIGITS BELOW TO NEAR 10 ABOVE.
FOR SUNDAY AFTERNOON/EVENING...LOOKING AT ANOTHER WEAK MID-LEVEL
TROUGH DROPPING ACROSS THE REGION. NAM INDICATING DECENT AMOUNT OF
850-500MB FRONTOGENESIS WITH THE TROUGH AS IT DROPS SOUTHEAST ACROSS
THE AREA. BASED ON THIS SIGNAL...ADDED MENTION OF FLURRIES AS NAM
BUFKIT SOUNDINGS SHOWING ALMOST TOTAL COLUMN SATURATION. PLAN ON
HIGHS MOSTLY IN THE TEENS...WITH A FEW LOWER 20S ACROSS NORTHEAST IA
INTO FAR SOUTHWEST WI. NORTHWEST WINDS AND A PUSH OF ARCTIC AIR
OVERSPREAD THE AREA OVERNIGHT WITH LOWS DIPPING DOWN INTO THE SINGLE
DIGITS ABOVE AND BELOW ZERO. COMBINED WITH NORTHWEST WINDS AROUND 10
MPH...LOOKING FOR WIND CHILL VALUES IN THE TEENS TO NEAR 20 BELOW
ACROSS PARTS OF SOUTHEAST MN INTO NORTH CENTRAL WI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 209 PM CST SAT JAN 10 2015
COLD START TO THE NEW WORK WEEK AS MODIFIED ARCTIC AIRMASS MOVES
ACROSS THE REGION. PLAN ON HIGHS MONDAY AND TUESDAY IN THE SINGLE
DIGITS/TEENS ABOVE ZERO WITH LOWS MONDAY NIGHT IN THE SINGLE DIGITS
ABOVE AND BELOW ZERO.
LOOKING AT A SLOW WARMING TREND THEN FOR WEDNESDAY THROUGH SATURDAY
AS FLOW ACROSS THE CONUS BECOMES MORE HIGH ZONAL. THIS WILL TAP MORE
PACIFIC ORIGIN AIR INTO THE REGION WITH ARCTIC AIR RETREATING BACK
NORTH OF THE CANADIAN BORDER. MODEL CONSENSUS PRODUCES HIGH
TEMPERATURES WEDNESDAY IN THE TEENS TO LOWER 20S...THEN MODERATING
INTO THE UPPER 20S TO LOWER 30S BY FRIDAY AND SATURDAY. INCREASE IN
MID-LEVEL HEIGHTS/RIDGING KEEPS ANY WEATHER WELL NORTH OF THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 525 PM CST SAT JAN 10 2015
SOME MVFR CEILINGS HAVE FORMED OVER SOUTHEAST MINNESOTA AND WILL
LIKELY TRACK TO THE EAST THIS EVENING. RST HAS DROPPED TO AROUND
3KFT AND THE SAME IS EXPECTED AT LSE. WINDS WILL REMAIN ON THE
LIGHT SIDE AS A WEAK COLD FRONT DROPS DOWN INTO THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM....DAS
LONG TERM.....DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
923 PM CST SAT JAN 10 2015
.UPDATE...
REMOVED SLIGHT CHANCE OF LIGHT SNOW/FLURRIES FROM FORECAST AS RELATIVELY
HIGHER 24-27DBZ RETURNS ON RADAR HAVE MOVED OFF TO THE NE WITH
BETTER LAYER Q-VECTOR CONVERGENCE...DRIVEN BY 850-700MB WARM-AIR
ADVECTION. DRY LAYER BELOW 5K FT ON RAP AND NAM SOUNDINGS
PREVENTED LIGHT SNOW FROM REACHING THE GROUND THOUGH A FEW
FLURRIES MAY HAVE MADE IT TO THE SURFACE.
WARM ADVECTION ALSO BRINGING 925 MB TEMPERATURES UP...AND SURFACE
TEMPS AS WELL...SO THAT THE HIGHS FOR THE DAY WILL BE REACHED
THIS EVENING. TEMPERATURES STEADY OUT FOR A TIME BETWEEN 06Z AND
08Z THEN COOL A FEW DEGREES AS 925 MB THERMAL RIDGE SHIFTS OFF TO
THE EAST AS TROUGH SLOWLY SINKS INTO CENTRAL WISCONSIN.
TROUGH WAS THE FOCUS OF CONCERN FOR MEASURABLE PCPN/A FEW TENTHS
OF AN INCH OF SNOW IN FAR SOUTHEAST WISCONSIN SUNDAY EVENING.
LATEST NAM IS NOW SHIFTING PCPN SHIELD BACK TO THE SOUTHEAST WITH
MAYBE 0.01 INCH OF LIQUID MAKING IT INTO FAR SOUTHEAST KENOSHA
COUNTY. WILL MAKE NO CHANGE TO FORECAST FOR THIS PERIOD AT THIS
TIME...BUT NEXT SHIFT WILL HAVE TO SEE WHAT FULL 00Z MODEL SUITE
SHOWS.
&&
.AVIATION/06Z TAFS/...
WILL BE SEEING VFR CIGS THROUGH A GOOD PORTION OF THE
FORECAST...WITH CEILINGS FALLING TO MVFR AS SURFACE TROUGH/COLD
FRONT DROP THROUGH REGION SUNDAY EVENING. CURRENT CLOUD DECK DUE
TO WARM ADVECTION RIDING IN ON 25 TO 30 KT 925 MB WINDS. SOME
MIXING BROUGHT A FEW GUSTS TO THE SURFACE...BUT CONTINUING WARM
AIR ADVECTION STRENGTHENING INVERSION AND LESSENING THE CHANCE FOR
GUSTS OVERNIGHT.
WAS SOME CONCERN FOR A FEW TENTHS OF AN INCH OF SNOW AT EASTERN
SITES SUNDAY EVENING...BUT LATEST RUN OF THE NAM INDICATING PCPN
SHIELD IS SHIFT BACK TO THE SOUTHEAST...WITH ONLY A 0.01 OF AN
INCH OF LIQUID POSSIBLY REACHING AS FAR NORTH AS KENW. WILL LEAVE
OUT OF TAFS FOR NOW.
&&
.MARINE...
ISSUED A SMALL CRAFT ADVISORY UNTIL 09Z AS TIGHTENING PRESSURE
GRADIENT AND MIXING UP TO 30 KNOT WINDS AROUND 900 FT IS PRODUCING
18-20 KT SUSTAINED WINDS WITH GUSTS TO 25 KNOTS PER SHIP OBS OVER
THE NEARSHORE WATERS. WINDS WILL LOWER AS GRADIENT RELAXES WITH TROUGH
DIPPING INTO THE AREA DURING THE MID-OVERNIGHT HOURS
&&
.PREV DISCUSSION... /ISSUED 330 PM CST SAT JAN 10 2015/
TONIGHT AND SUNDAY...CONFIDENCE - HIGH.
SHOULD SEE MOSTLY CLOUDY SKIES CONTINUE TONIGHT...AS TEMPS ALOFT
CONTINUE TO RISE. MAY BE ENOUGH LIFT FOR SOME LIGHT SNOW OR FLURRIES
THROUGH THE EVENING HOURS...THOUGH DRIER AIR IN THE LOW LEVELS WILL
MAKE IT DIFFICULT FOR SNOW TO REACH THE GROUND. THE WARM ADVECTION
AND MOSTLY CLOUDY SKIES WILL KEEP TEMPS FROM FALLING MUCH
OVERNIGHT...WITH LOWS IN THE TEENS EXPECTED MOST PLACES.
MOSTLY CLOUDY SKIES WILL LIKELY CONTINUE THROUGH THE DAY SUNDAY...AS
A COLD FRONT SLOWLY DROPS SOUTH THROUGH THE FORECAST AREA.
INTRODUCED SOME LOW POPS FAR SOUTHEAST LATE IN THE AFTERNOON...AS
MODELS HAVE BEEN CREEPING NORTHWARD WITH LIGHT SNOW POTENTIAL. NAM
SOUNDINGS AT KENOSHA ARE FAIRLY SATURATED BY LATE AFTERNOON...WITH
SOME WEAK LIFT ALSO PRESENT.
HIGH TEMPS SUNDAY ARE EXPECTED TO CLIMB INTO THE 20S FOR THE FIRST
TIME SINCE EARLIER IN THE MONTH. MILDEST TEMPS WILL BE IN THE
SOUTHEAST AHEAD OF THE APPROACHING FRONT.
SUNDAY NIGHT THROUGH TUESDAY...CONFIDENCE - MEDIUM TRENDING TOWARD
HIGH.
ALL SHORT TERM MODEL GUIDANCE IN AGREEMENT ON SLOWING DOWN EWD
PROGRESSION OF LOW TO MID LEVEL TROF MOVING ACROSS SRN WI SUN AFTN
AND NIGHT. AS A RESULT EXPANDING PRECIPITATION SHIELD FROM
DEVELOPING LOW PRESSURE ALONG FRONTAL BOUNDARY AND BAROCLINIC ZONE
OVER TN AND OH VALLEYS MAY BE ABLE TO MAKE INROADS INTO FAR
SOUTHEAST WI FROM LATE SUN AFTN THRU SUN NGT. STRONGEST SYNOPTIC
SCALE LIFT REMAINS WELL TO THE SOUTH...HOWEVER TREND HAS BEEN
FARTHER TO THE NORTH. FOR NOW...WILL INTRODUCE MID-RANGE CHANCE
POPS INTO THE SOUTHEAST WITH THE POTENTIAL FOR A QUICK 1 INCH OF
ACCUMULATION AT ENW. SNOW LIQUID RATIOS WOULD BE LOW AROUND 10 TO
1. IF TREND CONTINUES...WL NEED TO EXPAND HIGHER POPS INTO AREA
FROM MKE TO JVL.
SYNOPTIC SCALE FORCING SLIDES OFF TO THE EAST LATER SUN NGT AS
STEERING FLOW INCREASES FROM THE W TO NW. FEW FLURRIES MAY
ACCOMPANY SHORT WAVE TROF MOVING THRU SUN NGT ELSEWHERE.
OTRW...COLD AIR RETURNS LATER SUN NGT AND CONTINUES TO PLUNGE INTO
THE AREA ON MON. LITTLE RECOVERY EXPECTED ON MON WITH BRISK
NORTHWEST WINDS.
OTHER SHORT TERM ISSUE ARISES LATE MON AFTN THRU MON NIGHT. LOW
LEVEL WINDS BEGIN TO VEER DURING THIS TIME. LITTLE COLUMN MOISTURE
ABV 3K FEET...HOWEVER NORTH WINDS ONLY SLOWLY VEER TO THE EAST MON
NGT INTO EARLY TUE AND SLOWLY DECREASE. LOW LEVEL WINDS AROUND
20KTS MON EVE...ONLY SLOWLY DECREASE TO AROUND 10KTS BY TUE EVE.
PLENTY OF THIN ICE IN NEAR SHORE WATERS BUT ICE CONCENTRATION
REMAINS LOW. HENCE USING A LAKE TEMP AROUND 1C...GETTING DELTA-T
AROUND 14 DEGREES WITH LAKE INDUCED CAPE AROUND 200 J UP TO SHALLOW
INVERSION AROUND 3K FEET. ENOUGH TIME FOR FETCH AND CONVERGENCE TO
PRODUCE FLURRIES AND POSSIBLE A FEW HEAVIER -SHSN...ESPECIALLY FROM
MKE SOUTHWARD. BUMPED UP POPS IN THIS AREA MON NGT...AND KEPT
FLURRIES GOING INTO TUE MRNG.
TUESDAY NIGHT THROUGH SATURDAY...CONFIDENCE - MEDIUM.
SPRAWLING HIGH PRESSURE WILL GRADUALLY WEAKEN AND SAG SOUTH OF THE
REGION ON WED...SUCCUMBING TO INCREASING NORTHWEST FLOW ALOFT AS
UPSTREAM RIDGE AMPLIFIES OVER WRN CONUS. MEANWHILE...SHORT WAVE
SPOKES WL CONTINUE TO ROTATE AROUND POLAR LOW LOCATED WELL NORTH OF
HUDSON BAY AS LONG WAVE TROFFING EXPANDS INTO ERN GTLAKES/CONUS
LATER IN THE WEEK.
MEDIUM RANGE DESCREPANCY SHOWS UP WED NGT INTO THU WITH REGARDS TO
STRENGTH OF NW STEERING WINDS AND COLD AIR INTRUSION INTO WRN
GTLAKES ON THU. GFS AND CMC NOW MORE AGGRESSIVE ON GREATER SURGE OF
COLDER AIR REACHING SRN WI ON THU WHILE ECMWF DELAYED WITH COLD AIR
REMAINING TO THE NORTH. WPC FAVORS MODEL TREND WHICH REDUCES
STRENGTH OF THU COLD AIR SURGE.
NEVER THE LESS...COLD AIR SURGE WOULD BE BRIEF AS UPSTREAM RIDGE
BREAKS DOWN LATE IN THE WORK WEEK. THIS RESULTS IN MORE ZONAL TO
WNW STEERING FLOW AND WARMER AIR POSSIBLY SURGING IN ON FRI AND SAT.
EARLIER ECMWF RUNS HAD SHOWN HIGHER AMPLITUDE SHORT WAVE TRACKING
SOUTHEAST IN STEERING FLOW EARLY IN THE WEEKEND...BUT HAVE NOW
TRENDING AWAY TOWARD GFS FLATTER SOLUTION. GLOBAL ENSEMBLE AND NORTH
AMERICAN ENSEMBLE MEAN LEANING TOWARD FLATTER SOLUTION AS WELL...SO
NO POPS PLANNED FOR WEEKEND AT THIS POINT...WITH TEMPS LIKELY TO
RISE TO NEAR OR ABV SEASONAL NORMAL BY FRI
AVIATION/00Z TAFS/...
VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO TONIGHT. COULD BE SOME
FLURRIES OR LIGHT SNOW THIS AFTERNOON AND EVENING...BUT NOT
EXPECTING ANY ACCUMULATIONS GIVEN FAIRLY DRY CONDITIONS IN THE LOWER
LEVELS.
MODELS SHOW INCREASING SATURATION IN THE LOWER LEVELS LATER TONIGHT
INTO SUNDAY. NAM IS MUCH QUICKER AND MAYBE A BIT OVERDONE WITH LOW
LEVEL SATURATION COMPARED TO GFS. THUS...DELAYED ARRIVAL OF MVFR
CIGS IN TAFS...ESPECIALLY GIVEN UPSTREAM CONDITIONS.
COULD SEE A LITTLE LIGHT SNOW IN THE FAR SOUTHEAST LATE SUNDAY
AFTERNOON AND INTO THE EVENING...AS COMPUTER MODELS HAVE BEEN
CREEPING NORTHWARD THE LAST COUPLE DAYS WITH THIS SYSTEM.
MARINE...
SEEING A FEW GUSTS TO NEARLY 25 KNOTS THIS AFTERNOON...BUT OVERALL
CONDITIONS SEEM TOO BORDERLINE FOR A SMALL CRAFT
ADVISORY...ESPECIALLY GIVEN THE ICE IN THE NEARSHORE WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 3 AM CST SUNDAY FOR LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/SUNDAY AND AVIATION/MARINE...DDV
SUNDAY NIGHT THROUGH SATURDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
525 PM CST SAT JAN 10 2015
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 209 PM CST SAT JAN 10 2015
NORTHWEST FLOW ALOFT CONTINUES ACROSS THE REGION PER LATEST WATER
VAPOR/500 MB RAP ANALYSIS. A WEAK MID-LEVEL WAVE/SURFACE TROUGH
WITHIN THIS FLOW WAS DROPPING INTO THE DAKOTAS/MN THIS AFTERNOON
WITH DECENT WING OF 285-290K ISENTROPIC LIFT/WAA OUT AHEAD OF IT
INTO OUR AREA. THIS HAS RESULTED IN WIDESPREAD EXPANSION OF
ALTOCUMULUS/STRATOCUMULUS THROUGH THE DAY. NO SNOW FLURRY ACTIVITY
YET PER SURFACE OBSERVATIONS...BUT RADAR PICKING UP ON VIRGA AROUND
3KFT...SO EXPECTING AT LEAST A FEW FLURRIES GOING THROUGH THE REST
OF THIS AFTERNOON. OTHERWISE...TEMPERATURES ACROSS THE AREA THIS
AFTERNOON WERE IN THE SINGLE DIGITS/TEENS ABOVE ZERO.
LOOK FOR THE MID-LEVEL WAVE/SURFACE TROUGH TO CONTINUE SLIPPING
SOUTHEAST INTO THE REGION THIS EVENING...AND THEN EAST OF THE AREA
AROUND MIDNIGHT. WILL KEEP MENTION OF FLURRIES IN THROUGH THE
EVENING HOURS...MAINLY NORTHEAST OF I-94 BUT THEN DROPPED THEM AFTER
MIDNIGHT WITH FORCING EXITING THE AREA. OTHERWISE...LOOKS LIKE
SUBSTANTIAL MID-LEVEL CLOUD COVER WILL LINGER THROUGH THE OVERNIGHT
HOURS. AS A RESULT...TEMPERATURES ONLY EXPECTED TO DROP INTO THE
SINGLE DIGITS BELOW TO NEAR 10 ABOVE.
FOR SUNDAY AFTERNOON/EVENING...LOOKING AT ANOTHER WEAK MID-LEVEL
TROUGH DROPPING ACROSS THE REGION. NAM INDICATING DECENT AMOUNT OF
850-500MB FRONTOGENESIS WITH THE TROUGH AS IT DROPS SOUTHEAST ACROSS
THE AREA. BASED ON THIS SIGNAL...ADDED MENTION OF FLURRIES AS NAM
BUFKIT SOUNDINGS SHOWING ALMOST TOTAL COLUMN SATURATION. PLAN ON
HIGHS MOSTLY IN THE TEENS...WITH A FEW LOWER 20S ACROSS NORTHEAST IA
INTO FAR SOUTHWEST WI. NORTHWEST WINDS AND A PUSH OF ARCTIC AIR
OVERSPREAD THE AREA OVERNIGHT WITH LOWS DIPPING DOWN INTO THE SINGLE
DIGITS ABOVE AND BELOW ZERO. COMBINED WITH NORTHWEST WINDS AROUND 10
MPH...LOOKING FOR WIND CHILL VALUES IN THE TEENS TO NEAR 20 BELOW
ACROSS PARTS OF SOUTHEAST MN INTO NORTH CENTRAL WI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 209 PM CST SAT JAN 10 2015
COLD START TO THE NEW WORK WEEK AS MODIFIED ARCTIC AIRMASS MOVES
ACROSS THE REGION. PLAN ON HIGHS MONDAY AND TUESDAY IN THE SINGLE
DIGITS/TEENS ABOVE ZERO WITH LOWS MONDAY NIGHT IN THE SINGLE DIGITS
ABOVE AND BELOW ZERO.
LOOKING AT A SLOW WARMING TREND THEN FOR WEDNESDAY THROUGH SATURDAY
AS FLOW ACROSS THE CONUS BECOMES MORE HIGH ZONAL. THIS WILL TAP MORE
PACIFIC ORIGIN AIR INTO THE REGION WITH ARCTIC AIR RETREATING BACK
NORTH OF THE CANADIAN BORDER. MODEL CONSENSUS PRODUCES HIGH
TEMPERATURES WEDNESDAY IN THE TEENS TO LOWER 20S...THEN MODERATING
INTO THE UPPER 20S TO LOWER 30S BY FRIDAY AND SATURDAY. INCREASE IN
MID-LEVEL HEIGHTS/RIDGING KEEPS ANY WEATHER WELL NORTH OF THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 525 PM CST SAT JAN 10 2015
SOME MVFR CEILINGS HAVE FORMED OVER SOUTHEAST MINNESOTA AND WILL
LIKELY TRACK TO THE EAST THIS EVENING. RST HAS DROPPED TO AROUND
3KFT AND THE SAME IS EXPECTED AT LSE. WINDS WILL REMAIN ON THE
LIGHT SIDE AS A WEAK COLD FRONT DROPS DOWN INTO THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM....DAS
LONG TERM.....DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
158 AM MST SUN JAN 11 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE TO BE THE STORY THROUGH THE EARLY
PART OF THIS WEEK...AS A SERIES OF FAST MOVING TROUGHS CONTINUE TO
MOVE THROUGH THE DESERT SOUTHWEST. SHOWERS WILL ONCE AGAIN BE
POSSIBLE LATE TONIGHT INTO MONDAY MORNING...FOLLOWED BY A SLIGHT
CHANCE AGAIN EARLY TUESDAY. HIGH PRESSURE WILL RETURN TO THE AREA BY
MID WEEK WITH DRY WEATHER AND SLOWLY INCREASING TEMPERATURES
EXPECTED FROM WEDNESDAY INTO NEXT WEEKEND.
&&
.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY CONTINUES TO INDICATE AN ACTIVE
PATTERN ACROSS THE WESTERN CONUS. THE VERY WEAK TROUGH THAT BROUGHT
A FEW LIGHT RAIN SHOWERS TO THE REGION ON SATURDAY WAS BARELY
VISIBLE ACROSS NEW MEXICO...MEANWHILE A COMPACT UPPER LOW WAS
SPINNING UP WEST OF LOS ANGELES AND ANOTHER WEAKER SYSTEM WAS
LOCATED OFF THE WASHINGTON/OREGON COAST NEAR 45N/135W. ACROSS THE
REGION AS OF 0845Z THIS MORNING...CONDITIONS WERE MOSTLY DRY
ALTHOUGH REGIONAL RADAR IMAGERY SUGGESTED A FEW SHOWERS WERE TRYING
TO SPILL OVER THE COASTAL MOUNTAINS INTO JOSHUA TREE NATIONAL PARK.
TEMPS WERE GENERALLY IN THE LOWER 50S ACROSS THE DESERTS WITH NEARLY
CALM WINDS AT ALL SITES.
THE LOW TO THE WEST OF LOS ANGELES HAS BEEN WELL ADVERTISED FOR THE
PAST SEVERAL DAYS...HOWEVER IT WOULD SUBJECTIVELY APPEAR THAT IT IS
A BIT MORE INTENSE THAN THE 00Z MODELS INDICATED. 00Z NAM AND GFS
AND TO SOME EXTENT THE EUROPEAN DON`T INDICATE ANY PRECIPITATION
ACROSS SOUTHERN CALIFORNIA THIS MORNING AND THIS IS OBVIOUSLY
INCORRECT. HRRR AND HI-RES MODELS ARE ALSO STRUGGLING A BIT AT THE
MOMENT BUT THE PARALLEL GFS /13KM/ SEEMS TO HAVE A DECENT HANDLE ON
THE SITUATION AND APPEARS TO HAVE INITIALIZED THE BEST OF ANY
AVAILABLE MODEL. GFS13 SUGGESTS THE LOW WILL MOVE ONSHORE LATER THIS
MORNING WITH PRECIPITATION DEVELOPING OVER ARIZONA LATER THIS
AFTERNOON/EVENING AS IT TAPS INTO SOMEWHAT HIGHER MID/LOWER
TROPOSPHERIC MOISTURE. MODEL QPF OVER THE PAST FEW DAYS HAS NEVER
BEEN MUCH MORE THAN A FEW HUNDREDTHS TO A TENTH OF AN INCH ACROSS
THE DESERTS /CLOSER TO A QUARTER OF AN INCH EAST OF PHOENIX/ AND
THIS STILL HOLDS TRUE WITH TODAY`S 00Z MODELS /INCLUDING THE GFS13/.
LOOKS LIKE A HIGH POP...LOW QPF EVENT. BUMPED UP POPS QUITE A BIT
THIS EVENING AND OVERNIGHT FOR ARIZONA ALTHOUGH SOUTHEAST CALIFORNIA
MAY END UP MISSING OUT ON THE MAJORITY OF THE RAINFALL. TIMING IS
LARGELY UNCHANGED FROM WHAT I INHERITED /06Z-18Z MONDAY IS THE
PRIMARY TIME FOR RAIN CHANCES/.
SHOWERS WILL TAPER OFF QUICKLY MONDAY NIGHT YET MOISTURE WILL REMAIN
SOMEWHAT ELEVATED BEHIND THE DEPARTING TROUGH. ON ITS HEELS WILL BE
THE SYSTEM PRESENTLY WEST OF WASHINGTON/OREGON AS IT IS FORECAST TO
DIVE SOUTHWARD THROUGH THE GREAT BASIN AND INTO ARIZONA TUESDAY
MORNING. AS THERE WILL BE SOME MOISTURE IN PLACE AND THE COLD CORE
OF THE LOW WILL PASS SOMEWHAT CLOSE TO THE FORECAST AREA...I WILL
RETAIN AT LEAST A 20-30 POP EAST OF PHOENIX FOR TUESDAY/TUESDAY
AFTERNOON PER SREF AND NAEFS GUIDANCE. HOWEVER THE OVER-LAND
TRAJECTORY OF THIS TROUGH SHOULD MITIGATE WIDESPREAD PRECIPITATION
ACROSS THE REST OF THE AREA.
LOOKING AHEAD TO WEDNESDAY AND BEYOND...RIDGING WILL RETURN TO THE
AREA BUT NOT NEARLY TO THE EXTENT AS WAS SEEN A FEW DAYS AGO. THIS
SHOULD RESULT IN GRADUALLY INCREASING TEMPERATURES AND LITTLE TO NO
CHANCE OF PRECIPITATION ACROSS THE AREA. HIGHS WILL EVENTUALLY CREEP
BACK INTO THE MID 70S BY LATE WEEK/NEXT WEEKEND.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
RESIDUAL MOISTURE WILL ENSURE MID AND HIGH LEVEL CIGS WILL PERSIST
THROUGH AT LEAST SUNDAY EVENING. POSSIBLY DIPPING AS LOW AS 7K-8K FT
AT TIMES...CIGS SHOULD NOT POSE MUCH OF AN AVIATION CONCERN...AND
ORGANIZED SHOWERS SHOULD HOLD OFF UNTIL LATER SUNDAY NIGHT. SFC
WINDS WILL REMAIN VERY LIGHT WITH PROLONGED PERIODS OF VARIABLE
DIRECTION...THOUGH GENERALLY FAVORING SOME EASTERLY COMPONENT
THROUGH SUNDAY AFTERNOON...THEN EVENTUALLY CARRYING SOME WESTERLY
DRIFT BY SUNSET.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
TUESDAY WILL SEE THE FINAL IN A SERIES OF TROUGHS MOVE THROUGH THE
AREA. LOOKS LIKE THE BEST CHANCE OF PRECIPITATION WILL BE IN THE
MOUNTAINS EAST OF PHOENIX. SHOWERS SHOULD TAPER OFF QUICKLY TUESDAY
NIGHT WITH DRY WEATHER FORECAST WEDNESDAY INTO THE WEEKEND. THERE
COULD ALSO BE SOME LOCALIZED BREEZINESS WITH THE TUESDAY SYSTEM
ESPECIALLY DOWN THE COLORADO RIVER AND ACROSS THE RIDGETOPS EAST OF
PHOENIX. NOTHING HIGH ENOUGH TO WARRANT ANY FIRE WEATHER HEADLINES
THOUGH. AS FOR MOISTURE...HUMIDITIES WILL DROP A BIT FROM MID WEEK
ONWARD YET AFTERNOON READINGS WILL ONLY DROP INTO THE 20-30 PERCENT
RANGE WITH GOOD OVERNIGHT RECOVERIES EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...MO
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
915 PM PST SAT JAN 10 2015
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL BRING OCCASIONAL LIGHT RAIN AND HIGH
ELEVATION MOUNTAIN SNOW TONIGHT AND SUNDAY AS IT MOVES ACROSS
SOUTHERN CALIFORNIA. DRY AND COOL ON MONDAY IN NORTHERLY FLOW ALOFT.
WARMER TUESDAY THROUGH THURSDAY WITH GUSTY OFFSHORE WINDS AS SURFACE
HIGH PRESSURE BUILDS OVER THE GREAT BASIN. MILD AND DRY CONDITIONS
WILL CONTINUE INTO NEXT WEEKEND WITH SEASONAL TEMPERATURES.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
9 PM RADAR IMAGERY SHOWED A LARGE BAND OF LIGHT RAIN OVER THE
COASTAL WATERS MOVING NORTHEAST INTO ORANGE AND SAN BERNARDINO
COUNTIES. THE EASTERN EDGE OF THIS RAIN BAND BROUGHT 0.20-0.30" OF
PRECIP TO NORTHWEST ORANGE COUNTY AND THE SAN BERNARDINO MOUNTAINS
TODAY. FARTHER SOUTHEAST MEASURABLE RAIN WAS HARD TO FIND IN
RIVERSIDE AND SAN DIEGO COUNTIES WHERE ONLY A FEW LIGHT
SHOWERS/SPRINKLES WERE REPORTED.
THE MOISTURE INCREASE ACROSS SOCAL THE PAST 24 HOURS HAS BEEN
SIGNIFICANT. THE PRECIPITABLE WATER ON THE 12Z NKX SOUNDING WAS
0.55". THIS EVENING IT JUMPED TO 1.05". THIS WILL SUPPORT CONTINUED
LIGHT PRECIP THROUGH SUNDAY WITH THE RAIN WILL GRADUALLY SHIFTING
EASTWARD TONIGHT WITH THE UPPER TROUGH. LIGHT PRECIPITATION WILL
BECOME MORE WIDESPREAD SUNDAY MORNING WHEN THE SHORTWAVE MOVES
ACROSS SOUTHERN CALIFORNIA. THERE MAY BE EMBEDDED AREAS OF MODERATE
RAIN SUNDAY MORNING WITH THE SHORTWAVE ALOFT AND WEAK LOW LEVEL
CONVERGENCE WITH THE SURFACE TROUGH.
THE HIGH REZ WRF AND HRRR MODELS HAVE NOT HANDLED QPF WITH THIS
SYSTEM VERY WELL. NOT QUITE SURE WHY. THE GLOBAL GFS AND ECMWF ARE
PERFORMING BETTER AND WERE THE PREFERRED MODELS THIS EVENING.
HIGHEST PRECIP AMOUNTS WILL BE OVER THE SAN BERNARDINO MOUNTAINS
WHERE WEAK BUT CONTINUOUS SOUTHERLY FLOW AHEAD OF THE TROUGH WILL
ENHANCE OROGRAPHICS. AN INCH OF RAIN IS POSSIBLE IN THIS AREA BY
SUNDAY EVENING. OROGRAPHICS WILL NOT BE A FACTOR IN THE SAN JACINTO
AND SAN DIEGO COUNTY MOUNTAINS.
ASIDE FROM THE SAN BERNARDINO MOUNTAINS...RAIN TOTALS WILL RANGE
FROM A TENTH TO A HALF INCH...MOST OF IT IN THE FORM OF
STEADY...LIGHT BENEFICIAL SOAKING RAINS. SNOW LEVELS FROM 6500-7000
FEET WILL CONFINE ACCUMULATING SNOW TO THE HIGHER ELEVATIONS OF THE
SAN BERNARDINO AND SAN JACINTO MOUNTAINS. THE PRECIP WILL TAPER OFF
SUNDAY EVENING AND END SUNDAY NIGHT.
MONDAY THROUGH WEDNESDAY...ONSHORE FLOW MONDAY WILL SHIFT OFFSHORE
TUESDAY AND WEDNESDAY AS A STRONG INSIDE SLIDER DIVES SOUTHWARD
ACROSS THE GREAT BASIN AND OVER THE LOWER COLORADO RIVER VALLEY.
GUSTY OFFSHORE WINDS WILL BEGIN ON TUESDAY...WITH PEAK WINDS TUESDAY
NIGHT AND WEDNESDAY WHEN WIND ADVISORIES MAY BE NEEDED. THE
DRY OFFSHORE FLOW WILL CLEAR OUT THE MARINE LAYER WEST OF THE
MOUNTAINS AND ALSO PUSH MAX TEMPS SEVERAL DEGREES ABOVE AVERAGE LATE
NEXT WEEK.
&&
.AVIATION...
100400Z...SCT-BKN CLOUD DECKS IN THE 6000-20000 FT MSL LAYER OVER
AND WEST OF THE MOUNTAINS AND OVER THE HIGH DESERTS THROUGH 11/0900
UTC...WITH EMBEDDED LIGHT SHOWERS/SPRINKLES AND LOCAL VIS 5 SM
POSSIBLE AT TIMES. SHOWERS INCREASING IN COVERAGE AND SLIGHTLY IN
INTENSITY OVER AND WEST OF THE MOUNTAINS AND THE HIGH DESERTS
OVERNIGHT...WITH MULTIPLE BKN-OVC CLOUD LAYERS 3000-15000 FT
MSL...AREAS OF VIS 3-5 SM...LOCALLY AOB 2 SM...AND MOUNTAIN
OBSCURATION ABOVE 3000 FT MSL. LOWER DESERTS WILL EXPERIENCE MOSTLY
UNRESTRICTED VIS...WITH FEW-SCT CLOUDS AOA 10000 FT MSL...BECOMING
SCT-BKN IN THE 6000-15000 FT MSL LAYER AFTER 11/0900 UTC WITH A
POSSIBLE ISOLATED SHOWER AT TIMES PRODUCING VIS DOWN TO 5 SM AND BKN
CIGS DOWN TO 3000 FT MSL. SHOWERS DECREASING BY 11/18Z...TAPERING
OFF THROUGH SUNDAY EVENING.
&&
.MARINE...
800 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH WEDNESDAY.
&&
.BEACHES...
800 PM...SURFLINE SURF REPORTS STILL INDICATE SURF OF 3-5 FEET
OCCURRING MAINLY SOUTH OF DEL MAR AND NORTH OF NEWPORT BEACH. SURF
WILL DECLINE TONIGHT THROUGH SUNDAY AS THE SWELL DIMINISHES.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MOEDE
AVIATION/MARINE/BEACHES...23
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
445 AM EST SUN JAN 11 2015
.SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
INVERTED COASTAL TROUGH IS FINALLY NEARING THE COAST WITH LIGHT RAIN
SHOWERS MOVING ONSHORE ROUGHLY NORTH OF MAYPORT EARLY THIS MORNING.
COMPLICATED SCENARIO IS MAKING FOR A LOW CONFIDENCE FORECAST TODAY
BUT THE THINKING IS THAT SHOWER ACTIVITY WILL CONTINUE TO INCREASE
THIS MORNING AS AN UPPER LEVEL DISTURBANCE (CURRENTLY OVER THE
NORTHEAST GULF OF MEXICO) MOVES NORTHEAST ACROSS OUR REGION. THIS
WILL PROVIDE UPPER SUPPORT THAT SHOULD LEND A HELPING HAND TO LIFT
ALREADY PRESENT ALONG THE COASTAL TROUGH AT THE SURFACE.
PRECIP TIMING WILL BE A CHALLENGE TODAY BUT THE GENERAL EXPECTATION
IS FOR SCATTERED TO NUMEROUS SHOWERS ALONG THE COAST WITH MUCH
LESSER CHANCES FARTHER INLAND. WE SHOULD SEE A DECREASING TREND IN
RAIN CHANCES LATER THIS AFTERNOON INTO THIS EVENING IN THE WAKE OF
THE FIRST UPPER DISTURBANCE. TEMPERATURES WILL BE CHALLENGING TODAY
AND WE HAVE FAVORED A MODEL BLEND WHICH RESULTS IN A WIDE RANGE OF
MAX TEMPS...LOW 50S NORTH TO MID 70S SOUTH. MOSTLY CLOUDY SKIES ARE
EXPECTED TO PERSIST THROUGH THE DAY.
THERE SHOULD BE A LULL IN PRECIP THIS EVENING BEFORE A STRONGER
UPPER LEVEL DISTURBANCE LIFTS NORTHEAST OUT OF THE GULF OF MEXICO
AND MOVES INTO OUR REGION AFTER MIDNIGHT TONIGHT. THIS WILL BRING
A SIGNIFICANT INCREASE IN RAIN CHANCES LATE TONIGHT(EARLY MONDAY
MORNING) WITH EVEN A FEW THUNDERSTORMS EXPECTED DUE TO INCREASING
ELEVATED INSTABILITY. CLOUD COVER AND WARM MOIST SOUTHERLY FLOW
WILL RESULT IN A MILD NIGHT WITH TEMPS IN THE 50S AND 60S FOR MOST
AREAS.
SHORTWAVE ENERGY WILL MOVE NORTHEASTWARD THROUGH OUR REGION ON
MONDAY...PROMPTING A WARM FRONT TO LIFT NORTHWARD FROM THE FL
PENINSULA. THIS WILL INDUCE STRONG ISENTROPIC LIFT...AND A COUPLE OF
WAVES OF SHOWERS AND EMBEDDED THUNDERSTORMS WILL STREAM ACROSS OUR
AREA FROM THE GULF OF MEXICO. ONE BATCH WILL MOVE ONSHORE INTO THE
SUWANNEE VALLEY AND SOUTHEAST GA DURING THE EARLY MORNING
HOURS...WITH ANOTHER SHOT OF MOSTLY ELEVATED CONVECTION POSSIBLE
DURING THE AFTERNOON HOURS. RAINFALL AMOUNTS WILL AVERAGE AROUND A
HALF INCH. THE WARM FRONT SHOULD LIFT NORTHWARD INTO INTERIOR
SOUTHEAST GA BY LATE MONDAY AFTERNOON...AND DECREASING COVERAGE OF
RAINFALL FROM SOUTHWEST TO NORTHEAST SHOULD ALLOW HIGHS TO CLIMB
WELL INTO THE 70S FOR NORTHEAST FL...WITH 60S EXPECTED FOR INTERIOR
SOUTHEAST GA. FORCING ALOFT WILL DECREASE MONDAY NIGHT AS SHORTWAVE
ENERGY DEPARTS. UNSEASONABLY WARM AND MOIST CONDITIONS WILL PREVAIL
AS A COLD FRONT ONLY SLOWLY APPROACHES FROM THE NORTHWEST. FOG
FORMATION SEEMS LIKELY...BUT DUE TO UNCERTAINTY IN CLOUD
COVER...KEPT ONLY PATCHY COVERAGE IN THE FORECAST GRIDS FOR NOW.
LOWS WILL RANGE FROM 55-60.
SOUTHWEST FLOW ALOFT WILL PREVAIL ON TUESDAY IN ADVANCE OF ANOTHER
SHORTWAVE THAT WILL BE TRAVERSING THE SOUTHEASTERN STATES.
MEANWHILE...STRONG HIGH PRESSURE WILL BEGIN TO WEDGE SOUTHWARD INTO
OUR AREA BY LATE TUES...PUSHING A COLD FRONT SLOWLY SOUTHWARD
THROUGH OUR REGION TUES NIGHT. ANOTHER ROUND OF FOG WILL BE POSSIBLE
TUES NIGHT AHEAD OF THIS FRONT. FORCING ALOFT SHOULD BE MINIMAL ON
TUESDAY...WITH WIDELY SCATTERED SHOWERS NEAR THE ALTAMAHA AS THE
COLD FRONT MOVES THROUGH AND ALONG THE COAST AS ONSHORE FLOW
STRENGTHENS...WITH ONLY ISOLATED ACTIVITY ELSEWHERE. ABOVE NORMAL
TEMPS WILL PREVAIL AHEAD OF THIS COLD FRONT....WITH MID/UPPER 60S
FOR SOUTHEAST GA AND COASTAL NORTHEAST FL...WHILE 70S PERSIST FOR
INLAND NORTHEAST FL. AS ONSHORE FLOW STRENGTHENS TUES NIGHT AND WED
IN CONCERT WITH THE FRONT SLIPPING SOUTHWARD...ISOLATED TO WIDELY
SCATTERED SHOWERS WILL REMAIN POSSIBLE REGION-WIDE. LOWS NORTH OF
THE FRONT WILL FALL BACK TO THE 40S FOR SOUTHEAST GA TUES
NIGHT...WITH 50S FOR NORTHEAST FL.
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE SOUTHWARD INTO THE FL PENINSULA ON WEDNESDAY
AS HIGH PRESSURE OVER THE MID-ATLANTIC AND THE TENNESSEE VALLEY
WEDGES SOUTHWARD INTO OUR AREA. NORTHEAST FLOW AND WEAK ISENTROPIC
LIFT WILL KEEP ISOLATED SHOWERS IN THE FORECAST...WITH CLOUDS AND
COOL AIR ADVECTION KEEPING HIGHS IN THE 50S FOR SOUTHEAST GA...WITH
60S FOR NORTHEAST FL. A DEEPENING LONG WAVE TROUGH WILL DIG INTO THE
SOUTHEASTERN STATES BY WED NIGHT AND THURS...INDUCING CYCLOGENESIS
ALONG THE FRONTAL BOUNDARY IN THE GULF OF MEXICO. THIS WAVE OF LOW
PRESSURE WILL MIGRATE EASTWARD ACROSS THE FL PENINSULA ON
THURS...WITH STRONG ISENTROPIC LIFT DEVELOPING STEADY RAINFALL OVER
MUCH OF OUR REGION BY LATE WED NIGHT INTO THURS. RAIN CHANCES FOR
THESE TIME PERIODS MAY NEED TO BE INCREASED IN FUTURE FORECASTS.
LOWS WED NIGHT WILL RANGE FROM THE 40S NORTH OF I-10 TO THE 50S
ELSEWHERE. HIGHS THURS WILL REMAIN IN THE 50S NORTH OF I-10...WITH
60S ELSEWHERE. A FEW LINGERING SHOWERS WILL BE POSSIBLE THURS NIGHT
IN NORTHEAST FL AS A COLD FRONT DRIVES SOUTHEASTWARD.
A SEASONABLY COOL AND DRY AIR MASS WILL BUILD INTO OUR REGION FOR
FRI AND SAT AS COOL HIGH PRESSURE SETTLES OVER THE SOUTHEASTERN
STATES. HIGHS WILL GENERALLY RANGE FROM 55-60...WITH LOWS DROPPING
BACK TO THE 30S INLAND AND 40S AT THE COAST. TEMPERATURES WILL
MODERATE SATURDAY NIGHT AND NEXT SUNDAY AS HIGH PRESSURE MOVES OFF
THE U.S. EASTERN SEABOARD AND ONSHORE WINDS DEVELOP.
&&
.AVIATION...
THE HRRR MODEL HAS RECENTLY BACKED WAY OFF ON LOW CEILINGS THIS
MORNING AND THIS SEEMS TO BE PLAYING OUT AS ALL NORTHEAST FLORIDA
TAF SITES ARE NOW REPORTING VFR CONDITIONS. THE CEILING FORECAST
WILL BE DIFFICULT TO SAY THE LEAST THROUGHOUT THE DAY BUT THE
IMPROVED CEILING HEIGHTS WILL LIKELY CONTINUE THROUGH MUCH OF THE
MORNING BEFORE LOW CEILINGS REDEVELOP ALONG THE COAST EARLY THIS
AFTERNOON. RAIN SHOWERS WILL BE POSSIBLE AT THE COASTAL TERMINALS
OFF AN ON THROUGH THIS AFTERNOON. TIMING THIS ACTIVITY WILL PROVE
DIFFICULT BUT IMPACTS SHOULD BE BRIEF WITH MAINLY MVFR VISIBILITY
REDUCTIONS.
&&
.MARINE...
PREVAILING NORTHEAST TO EAST FLOW TODAY WITH SUSTAINED WINDS
GENERALLY AVERAGING 15 TO 20 KNOTS WITH THE HIGHER SPEEDS EXPECTED
OVER THE OFFSHORE WATERS. HAVE REPLACED THE SCA OVER THE NEARSHORE
WATERS WITH AN SCEC HEADLINE FOR TODAY. A DIMINISHING TREND IN THE
WINDS IS EXPECTED TONIGHT. AN SCA REMAINS IN EFFECT FOR THE
OFFSHORE WATERS THROUGH MONDAY TO ACCOUNT FOR THE POSSIBILITY OF
SEAS LINGERING IN THE 5 TO 7 FT RANGE. LIGHT WINDS WILL PREVAIL
MONDAY AND TUESDAY...BUT CONSIDERABLE UNCERTAINTY REMAINS IN THE SEA
HEIGHT FORECASTS. ANOTHER SURGE OF NORTH TO NORTHEAST WINDS AND
BUILDING SEAS IS EXPECTED TUESDAY NIGHT AND WEDNESDAY AS STRONG HIGH
PRESSURE BUILDS NORTH OF OUR REGION...PUSHING A COLD FRONT SOUTHWARD
THROUGH THE COASTAL WATERS. LOW PRESSURE WILL THEN MIGRATE EASTWARD
ACROSS THE FLORIDA PENINSULA ON THURSDAY...WITH A PERIOD OF STEADY
RAINFALL EXPECTED OVER THE COASTAL WATERS INTO THURSDAY EVENING.
RIP CURRENTS: MODERATE RISK TODAY DUE TO ONSHORE FLOW AND INCREASED
SURF.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 53 49 67 54 / 30 60 60 20
SSI 59 56 66 55 / 60 70 60 30
JAX 65 58 73 58 / 50 60 60 30
SGJ 70 62 72 60 / 60 50 60 30
GNV 70 60 76 58 / 20 60 60 20
OCF 76 62 77 60 / 20 50 60 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 5 PM EST MONDAY FOR ALTAMAHA SOUND GA
TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-FERNANDINA
BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-ST
AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ALTAMAHA
SOUND GA TO FERNANDINA BEACH FL OUT 20 NM-FERNANDINA BEACH
TO ST AUGUSTINE FL OUT 20 NM.
&&
$$
SHULER/NELSON
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
342 AM CST Sun Jan 11 2015
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1105 PM CST SAT JAN 10 2015
Timing of precip and precip type the main forecast concerns this
period. Next wave of low pressure will start to affect the area on
Sunday bringing a thickening and lowering cig during the morning
with some light snow, sleet and freezing rain affecting our southern
TAF sites (KSPI, KDEC and KCMI) in the 17z-19z time frame, with
our remaining northern sites (KBMI and KPIA) seeing more of a light
snow and sleet mixture move in from 19z-21z. Once the precip begins
it will be just a matter of an hour or two before we see cigs drop
from low VFR to MVFR, and then IFR/LIFR after 00z. Forecast soundings
suggest the higher probability for freezing rain would be from SPI
to DEC to near CMI with more of a sleet and light snow mix further
north at BMI, with mostly light snow expected at PIA. Surface
temperatures across our southern TAF sites will warm to near the
freezing mark but in all probability, should begin to cool off by
a degree or two after the precip begins.
Look for the light wintry mix to continue on and off thru the night
with a transition over to light snow as the night wears on due to
a cold front pushing acrs the area and cooling temps off just enough
in the lower levels of the atmosphere for the changeover to occur.
Surface winds will remain out of the south thru the day Sunday with
speeds of 10 to 15 kts and then start to veer more into a westerly
direction late in the evening as a cold front approaches and then
passes across our forecast area during the overnight hours.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from Noon today to 9 AM CST Monday FOR
ILZ042>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1149 PM CST SAT JAN 10 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 344 PM CST SAT JAN 10 2015
TEMPERATURES AND CLOUD COVER WERE THE MAIN FORECAST ISSUE FOR
TONIGHT AS SURFACE HIGH PRESSURE MOVES EAST THIS EVENING ALLOWING
FOR A WEAK TROUGH TO PUSH INTO THE STATE OVERNIGHT. FORECAST
SOUNDINGS SUGGEST AN INVERSION DEVELOPING THIS EVENING TRAPPING
LOW LEVEL MOISTURE AND RESULTING IN A STRATUS SHIELD OVER CENTRAL
TO NORTHERN IOWA. PRETTY HIGH RH AT 925MB THIS EVENING AND ALSO
SHOULD BE A LITTLE ADDED MOISTURE WITH THE STRONG WAA TODAY OVER
THE SNOW PACK. INCREASE CLOUD COVER TONIGHT WHICH SHOULD HELP KEEP
OVERNIGHT LOWS UP SLIGHTLY WARMER THAN PREVIOUSLY FORECAST. THE
HOPWRF AND HRRR HAVE CLOUD COVER THROUGH MUCH OF THE NIGHT OVER
THE NORTHERN SECTION OF THE FORECAST AREA.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 344 PM CST SAT JAN 10 2015
A FEW MINOR ISSUES IN THE NEAR TERM...WITH MAINLY A DRY AND QUIET
FORECAST THROUGHOUT THE MID/LONG RANGE. SOUTHERN STREAM UPPER
LEVEL TROUGH WILL BE LIFTING OUT OF THE SOUTHERN HIGH PLAINS
INTO THE OHIO VALLEY SUNDAY INTO EARLY MONDAY. ADDITIONALLY A
NORTHERN STREAM TROUGH WILL BE DROPPING THROUGH THE NORTHERN
PLAINS AND INTO THE GREAT LAKES WITH THAT WAVE SOMEWHAT SHEARING
APART AS IT DROPS SOUTH. WAA AND SOME WEAK THETA-E ADVECTION WILL
CREEP INTO THE FAR SOUTHEASTERN CWA WITH THE SOUTHERN STREAM
TROUGH...WHICH WILL BRING A CHANCE FOR SOME LIGHT SNOW TO THE FAR
SOUTHEASTERN CWA SUNDAY NIGHT. NAM SHOWS DEEPER SATURATION KEEPING
THE PRECIP MAINLY VERY LIGHT SNOW...WHILE THE GFS DOES SHOW SOME
QUESTION AS TO THE DEEPER SATURATION AND ICE INTRODUCTION WITH A
POTENTIAL FOR SOME VERY LIGHT FZDZ. OVERALL THE BULK OF THE PRECIP
IS EXPECTED TO STAY TO THE SOUTH AND SOUTHEAST OF THE CWA...SO
ONLY LIGHT ACCUMULATIONS UNDER AN INCH ARE POSSIBLE AND WENT WITH
HIGH CHANCE POPS. A STRONGER COLD FRONT WILL PUSH THROUGH THE CWA
WITH THE NORTHERN STREAM TROUGH AND COULD BRING SOME FLURRIES
SUNDAY NIGHT TO THE REMAINDER OF THE CWA...AND SOME GUSTY WINDS
INTO MONDAY. COLD ARCTIC HIGH PRESSURE TO BUILD INTO THE CWA FOR
MONDAY NIGHT INTO TUESDAY WITH TEMPS FALLING WELL BELOW NORMAL
AGAIN.
NORTHWESTERLY UPPER LEVEL FLOW REMAINS IN PLACE INTO
THURSDAY...WITH THE FLOW FLATTENING OUT SOME TOWARD THE WEEKEND.
THE MAIN PUSH OF SHORTWAVES SHOULD REMAIN TO THE NORTH OF THE
CWA...SO EXPECT DRY CONDITIONS WITH MAINLY AN INCREASE IN CLOUD
COVER. TEMPERATURES WARM ALOFT AS WELL THROUGH THE END OF THE
PERIOD...SO A WARMING TREND IS ON TAP THROUGH THE WEEKEND.
TEMPERATURES ARE EXPECTED TO REBOUND CLOSER TO THE SEASONAL
AVERAGE OR EVEN PUSH ABOVE AVERAGE TOWARD THE END OF THE FORECAST
PERIOD.
&&
.AVIATION...11/06Z
ISSUED AT 1149 PM CST SAT JAN 10 2015
SURFACE BOUNDARY WILL MOVE VERY SLOWLY SOUTH ACROSS THE FORECAST
AREA DURING THE REMAINDER OF THE NIGHT INTO SUNDAY. WHILE MOST
LOCATIONS WILL SEE VFR CEILINGS...LOCALIZED MVFR TO IFR CEILINGS
WILL OCCUR NEAR THE SURFACE FRONT AS IT DRIFTS SOUTHWARD. THERE
WILL BE INCREASING THREAT OF SOME LIGHT PRECIPITATION NEAR KOTM
LATE SUNDAY EVENING WITH LITTLE THREAT ELSEWHERE. WINDS WILL
INCREASE FROM THE NORTH LATE IN THE FORECAST PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...BEERENDS
AVIATION...COGIL
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
101 AM EST SUN JAN 11 2015
.UPDATE...
ISSUED AT 101 AM EST SUN JAN 11 2015
A LARGE AREA OF MID-LEVEL CLOUDS ARE MOVING IN FROM WESTERN KENTUCKY.
THESE WILL LIKELY MAKE IT INTO LOCATIONS WEST OF I-75 BEFORE
DAWN...LIKELY RESULTING IN TEMPERATURES RECOVERING SOMEWHAT OFF OF
THEIR OVERNIGHT LOWS. WILL FRESHEN UP THE FORECAST TO ACCOUNT FOR
THESE TRENDS.
UPDATE ISSUED AT 1043 PM EST SAT JAN 10 2015
HOURLY GRIDS HAVE BEEN UPDATED BASED ON RECENT TRENDS IN OBSERVATIONS.
THIS ALLOWED FOR SLIGHTLY LOWER MIN T IN SOME OF THE EASTERN AND
NORTHEASTERN VALLEYS AND IN THE EKQ AREA. OVERALL...NO SIGNIFICANT
CHANGES WERE NEEDED AT THIS TIME.
UPDATE ISSUED AT 725 PM EST SAT JAN 10 2015
ANOTHER CHILLY NIGHT IS IN STORE...ESPECIALLY IN THE VALLEYS...AS SFC
HIGH PRESSURE BEGINS TO DEPART TO THE EAST TONIGHT. THIS SHOULD SET
THE STAGE FOR A MODERATE RIDGE VALLEY SPLIT ON THE ORDER OF 8 TO 11
DEGREES. THE NORMALLY COLDER EASTERN SPOTS IN NE KY AND NEAR THE WV
AND VA BORDERS MIGHT REACH THE SINGLE DIGITS. ATTM...ONLY SOME
ADJUSTMENTS WERE MADE TO HOURLY TEMP AND DEWPOINT GRIDS BASED ON
RECENT OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 340 PM EST SAT JAN 10 2015
19Z SFC ANALYSIS SHOWS MODIFIED ARCTIC HIGH PRESSURE OVER EASTERN
KENTUCKY. THIS HAS KEPT THE SKIES CLEAR AND WINDS LIGHT TODAY
THROUGHOUT THE AREA...HELPING TO SEND TEMPERATURES INTO THE UPPER
20S AND LOWER 30S FOR MOST OF THE CWA...DESPITE AN AWFULLY CHILLY
START. READINGS AT 3 PM RANGE FROM 25 DEGREES JUST NORTH OF FLEMING
COUNTY TO 34 DEGREES IN BELL AND HARLAN COUNTIES. DEWPOINTS...
MEANWHILE...ARE GENERALLY IN THE LOW SINGLE DIGITS ABOVE ZERO.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE RETREAT OF THE DEEP
TROUGH RESPONSIBLE FOR THIS LATEST COLD BLAST TONIGHT AND THE
APPROACHING OF A WEAKER SOUTHERN STREAM TROUGH INTO SUNDAY NIGHT.
HEIGHTS WILL SLOWLY RISE FROM TONIGHT INTO THE DAY SUNDAY THOUGH
MORE ENERGY WILL START TO STREAM IN FROM THE SOUTHERN STREAM LATER
SUNDAY THROUGH SUNDAY NIGHT. WITH THE GOOD MODEL AGREEMENT HAVE
FOLLOWED THE HRRR AND NAM12 MOST CLOSELY FOR THIS SHORT TERM PORTION
OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE ANOTHER CHILLY NIGHT...BUT MILDER THAN
LAST NIGHT...UNDER MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS WILL SET
THE STAGE FOR A DECENT RIDGE TO VALLEY TEMPERATURE DIFFERENCE THROUGH
THE NIGHT. TEMPS WILL REBOUND THROUGH THE DAY SUNDAY EVEN AS CLOUDS
QUICKLY INCREASE AND THICKEN FROM THE WEST. WHILE READINGS ARE
EXPECTED TO RISE ABOVE FREEZING FOR THE ENTIRE CWA BEFORE THE CHANCES
OF LIGHT RAIN MOVE IN...THE DRY AIR IN PLACE MAY RESULT IN A MIXTURE
OF RAIN AND SLEET INITIALLY ALONG AND NORTH OF INTERSTATE 64. IN
ADDITION...THOUGH AIR TEMPERATURE WILL BE A COUPLE OF DEGREES ABOVE
FREEZING...PATCHY FREEZING RAIN WILL BE POSSIBLE DUE TO SUB FREEZING
ROAD TEMPERATURES AND SHADED LOCATIONS. ACCORDINGLY...HAVE ADDED A
TOUCH OF FREEZING RAIN TO THE WX GRIDS FROM LATE SUNDAY AFTERNOON
THROUGH EARLY EVENING. THEREAFTER...RAIN WILL BE THE PCPN TYPE
THROUGH THE REST OF THE NIGHT AS THE FIRST IN A SERIES OF LOW
PRESSURE WAVES RIDES THROUGH THE OHIO VALLEY. TEMPERATURES SHOULD BE
STEADY OR SLOWLY RISE THROUGH THE NIGHT. WILL ISSUE AN SPS TO ADDRESS
THE WINTRY MIX POTENTIAL FOR NORTHERN PARTS OF THE AREA LATE SUNDAY.
ONCE AGAIN USED THE BCCONSSHORT/SUPERBLEND AS A STARTING POINT FOR
THE T...TD...AND WIND GRIDS WITH SOME MODERATE TERRAIN BASED POINT
ADJUSTMENTS FOR LOWS TONIGHT. AS FOR POPS...ENDED UP IN LINE WITH THE
MET MOS THROUGH THE SHORT TERM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 240 PM EST SAT JAN 10 2015
WHILE CONFIDENCE IS HIGH TO START THE UPCOMING WEEK...CONFIDENCE
FADES AS WE HEAD INTO TUESDAY AND BEYOND AS QUESTIONS SWIRL WITH
JUST HOW FAR SOUTH A FRONTAL BOUNDARY STALLS...WHICH IN TURN WILL
DETERMINE JUST HOW ACTIVE AND WHAT TYPE OF PRECIPITATION WE DEAL
WITH THROUGH THURSDAY.
TO START THE PERIOD...A SHORTWAVE TROUGH WILL BE PUSHING ACROSS THE
AREA MONDAY...YIELDING A DAMP DAY WITH PERIODS OF RAIN AND DRIZZLE.
LIFT AND MOISTURE ARE ALL PRESENT TO SUPPORT CATEGORICAL POPS
THROUGH MOST OF THE DAY. BY MONDAY NIGHT...DEEPER MOISTURE WILL EXIT
TO THE SOUTH AND EAST AS A COLD FRONT PUSHES SOUTH. HOWEVER...MODEL
SOUNDINGS REMAIN SUPPORTIVE OF PERSISTENT PERIOD OF DRIZZLE THROUGH
MONDAY NIGHT AND INTO TUESDAY. AT THE SAME TIME...SHALLOW COLD AIR
WILL BE SPREADING SOUTH BEHIND THE COLD FRONT. THIS WILL SET UP THE
STAGE FOR SOME LIGHT FREEZING RAIN/DRIZZLE INTO TUESDAY MORNING.
FORECAST CONFIDENCE ERODES ON TUESDAY...AS GFS KEEPS THE BOUNDARY
FARTHER NORTH...KEEPING THE THREAT OF PRECIPITATION AROUND FOR MUCH
OF SOUTHEAST KENTUCKY THROUGH THE DAY. ON THE OTHER HAND...THE ECMWF
SINKS THE FRONT SOUTHWARD AND KEEPS THE AREA DRY THROUGH TUESDAY AND
BEYOND. SIMPLY CANNOT DISCOUNT THE GFS SOLUTION...SO WILL KEEP SOME
LOW POPS AROUND THROUGH TUESDAY. AS TEMPERATURES ARE NOT EXPECTED TO
CLIMB PAST FREEZING...ANY PRECIPITATION THAT DOES EXIST COULD POSE
PROBLEMS THROUGH THE DAY. HOWEVER...GFS DOES SHOW SOME MID LEVEL
MOISTURE SPREADING BACK OVERHEAD...POSSIBLY SUPPORTING FEEDER/SEEDER
PROCESSES BY LATE MORNING INTO THE AFTERNOON HOURS. AT THE SAME
TIME...STILL A BIT OF A WARM NOSE ON THE GFS SOUNDINGS THROUGH THE
DAY...SO ANY SEEDER FEEDER PROCESSES COULD JUST INCREASE THE
INTENSITY OF ANY FREEZING RAIN. HOWEVER...ANY SLIGHT CHANGES IN THE
LOWER TEMPERATURE PROFILE ON TUESDAY WOULD SIGNIFICANT ALTER
PRECIPITATION TYPE. THUS...PLANNING TO GO FAIRLY LIBERAL ON THE
PRECIPITATION TYPES THIS FAR OUT AND GO WITH A MIXTURE OF
SLEET/FREEZING RAIN/AND POSSIBLY SOME SNOW ENTERING THE PICTURE ON
TUESDAY.
BY TUESDAY NIGHT INTO THURSDAY...THE QUESTIONS REMAIN ON HOW FAR
NORTH PRECIPITATION CHANCES WILL LAST. THE ECMWF REMAINS LESS
OPTIMISTIC ON ANY PRECIPITATION CHANCES...WHILE THE GFS KEEPS SOME
CHANCES IN SOUTHEAST KENTUCKY THROUGH THURSDAY. GIVEN THE MODELS
DISAGREEMENT HAVE OPTED FOR SOME LOW POPS THROUGH THURSDAY ACROSS
SOUTHEAST KENTUCKY. IF PRECIPITATION OCCURS...THE THREAT FOR
FREEZING DRIZZLE...SNOW...AND RAIN WILL CONTINUE. THUS...THERE IS A
CHANCE FOR A AN EXTENDED PERIOD OF FROZEN PRECIPITATION IN SOUTHEAST
KENTUCKY. ALL MODELS ARE TRENDING DRIER BY LATE THURSDAY INTO NEXT
WEEKEND...SO WILL DRY OUT THE FORECAST FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 101 AM EST SUN JAN 11 2015
BESIDES SOME MID-LEVEL CLOUD COVER MOVING IN FROM THE WEST TOWARDS
DAWN...VFR CONDITIONS WILL HOLD ON THROUGH THE DAY. LIGHT
PRECIPITATION WILL THREATEN LOCATIONS FROM WEST TO EAST IN THE
AFTERNOON AND ESPECIALLY INTO THE EVENING HOURS. CEILINGS WILL LIKELY
LOWER TO MVFR BETWEEN 00 AND 06Z. WINDS WILL GENERALLY BE FROM THE
SOUTH AT AROUND 5 KTS OR LESS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
432 AM EST SUN JAN 11 2015
.SYNOPSIS...
TEMPERATURES WILL MODERATE TODAY FOLLOWED BY A WINTRY MIX OF
PRECIPITATION TONIGHT INTO MONDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
HIGH CLOUDS HAVE ENCOMPASSED MOST OF THE NORTHERN TWO-THIRDS OF
THE CWA THROUGH THE NIGHT. THIS HAS KEPT TEMPERATURES FROM
CRATERING TOO BAD ACROSS PENNSYLVANIA AND OHIO...HOWEVER TO THE
SOUTH...TEMPERATURES HAVE FALLEN OFF QUITE DECIDEDLY. IN
FACT...ACROSS THE NORTHERN TWO-THIRDS OF THE AREA...TEMPERATURES
HAVE MANAGED TO RECOVER A FEW DEGREES FROM EARLIER OVERNIGHT LOWS.
THAT SAID...DRASTIC CHANGES IN THE MOISTURE AND THERMODYNAMIC
PROFILES ACROSS THE CWA ARE IN STORE OVER THE NEXT 24 TO 36 HOURS
THAT WILL LIKELY HAVE FAR REACHING IMPACTS UPON TRAVEL AND
COMMERCE FOR MOST OF THE UPPER OHIO VALLEY.
MODEL SOLUTIONS HAVE BEEN LARGELY LATCHING ONTO A SYSTEM MOVING
THROUGH THE AREA THIS EVENING INTO MONDAY FOR SEVERAL DAYS. THE
OVERNIGHT MODEL RUNS WERE LITTLE CHANGED FROM THIS...HOWEVER THE
THERMODYNAMIC PROFILES THAT HAVE COME OUT OF THE MORE RECENT NAM
AND SREF ENSEMBLE RUNS HAVE BECOME MORE PROBLEMATIC FOR MUCH OF
THE FORECAST AREA. ADDITIONALLY...THE HRRR IS POINTING IN A
DIRECTION THAT MAKES THIS FORECASTER TAKE PAUSE DUE TO A WARMER
BOUNDARY LAYER THAN IN PREVIOUS RUNS. THESE WARMER SOLUTIONS WOULD
GENERALLY BE A SEEMINGLY GOOD THING TO SEE FROM THE
MODELS...HOWEVER THERE ARE A LOT OF THINGS THAT MAKE SEEING WARM
LAYERS IN THE MODELS HIGHLY PROBLEMATIC GOING FORWARD.
FIRST...OVERNIGHT LOWS ACROSS MOST OF THE AREA WERE IN THE SINGLE
DIGITS THIS MORNING...AFTER SEVERAL SUCCESSIVE DAYS OF ARCTIC
COLD. WHILE HIGHS WILL MODERATE SUBSTANTIALLY TODAY...HIGH CLOUDS
ARE FAIRLY COMMON THIS MORNING...AND A MID-CLOUD DECK IS RUNNING
QUICK ON THE HEELS OF THE MORNING HIGH CLOUDS FOR THIS AFTERNOON.
THIS WILL LIKELY LIMIT THE UPWARD MOBILITY OF TEMPERATURES THIS
AFTERNOON...EVEN WITH A DRY COLUMN...SOME MODEST MIXING...WARM
ADVECTION...AND SUBSTANTIALLY WARMER AIR COMING OVER THE REGION
OFF THE DECK. THAT SAID...IT SEEMS AT THE VERY LEAST THAT
EVERYWHERE SOUTH OF PITTSBURGH SHOULD ECLIPSE FREEZING
TODAY...WITH SOME AREAS TOWARD MORGANTOWN AND SUCH LIKELY RUNNING
ABOVE 40F THIS AFTERNOON. HOWEVER...WITH VERY COLD GROUND AND SNOW
COVER...THIS WARMER AIR WILL LIKELY DO LITTLE BEYOND WORK ON
MELTING SOME OF THE SNOW COVER...AND WITH LIMITED SUN...LIKELY
HAVE LITTLE EFFECT UPON THE GROUND ITSELF.
WITH FAIRLY DEEP ISENTROPIC LIFT MOVING INTO THE AREA AFTER 00Z
TONIGHT...THIS WILL ALSO ALLOW TIME FOR THE BOUNDARY LAYER TO
DECOUPLE AND LIKELY COOL A FEW DEGREES FROM THE DAYTIME HIGHS
PRIOR TO PRECIPITATION ONSET. THAT COMBINED WITH MODEST WARM
ADVECTION AND A STILL RATHER DRY COLUMN MAKES A CONTINUATION OF
WARMER BOUNDARY LAYER AIR PROBLEMATIC GOING INTO THE OVERNIGHT
ACROSS THE VAST MAJORITY OF THE AREA. IT WOULD SEEM WARM ADVECTION
SHOULD BE OVERCOME BY WET BULB COOLING...AND NAM AND GFS 925 MB
TEMPERATURES GENERALLY REVEAL THIS TREND FAIRLY WELL LATE THIS
EVENING. HOWEVER...THE NAM ALLOWS FOR SURFACE WARM ADVECTION TO
TAKE OVER AND WARM MUCH OF THE FORECAST AREA SOUTH OF A GENERAL
NEW CASTLE TO DUBOIS LINE ABOVE FREEZING IN THE LOW LEVELS SUCH
THAT IT SUGGESTS PLAIN RAIN WOULD BE LIKELY TO BE FALLING ACROSS
ALL OF THESE AREAS BY MONDAY MORNING. WHILE THIS IS CERTAINLY
METEOROLOGICALLY PLAUSIBLE...ANTECEDENT COLD AND ABUNDANT FROST
IN THE GROUND WILL ALMOST UNDOUBTEDLY CAUSE THE GROUND TO FREEZING
BACK UP OVERNIGHT TONIGHT. THAT SAID...WHETHER AIR TEMPERATURES
ARE BELOW FREEZING OR NOT MAY NOT BE PARTICULARLY MEANINGFUL TO
WHETHER RAIN IS FREEZING ON CONTACT WITH THE SURFACE OVER MUCH OF
THE AREA. AS SUCH...FOR AREAS WHERE MODEL SOUNDINGS SUGGEST RAIN
OR FREEZING RAIN...A FREEZING RAIN ADVISORY HAS BEEN HOISTED FOR
TONIGHT THROUGH MONDAY MORNING.
A BIT FURTHER NORTH AND GENERALLY IN CENTRAL OHIO TOWARD AREAS
JUST SOUTH OF I-80 IN PENNSYLVANIA...MODEL SOUNDINGS REALLY WAFFLE
QUITE A BIT IN HOW THEY HANDLE THE ELEVATED MELTING LAYER AND
WHETHER P-TYPES WILL REMAIN SNOW...SLEET...OR TREND TOWARD
FREEZING RAIN FOR A TIME. IN THIS CORRIDOR GENERALLY NORTH OF THE
PITTSBURGH AREA...INCLUDING ZANESVILLE...BUTLER...AND
PUNXSUTAWNEY...A WIDE RANGE OF WINTRY WEATHER IS EXPECTED. HOWEVER
HERE...AIR TEMPERATURES ARE GENERALLY LIKELY TO STAY BELOW
FREEZING THROUGHOUT THE EVENT. AS SUCH...SNOW AND ICE
ACCUMULATIONS ARE MUCH MORE LIKELY IN THIS CORRIDOR...WITH
PROBLEMS FROM BOTH LIKELY TO BE MORE LONG LASTING AS WELL.
AGAIN FARTHER NORTH...AND GENERALLY NORTH OF I-80...THE MAJORITY
OF THE MODEL GUIDANCE POINTS TOWARD A NEARLY ALL SNOW EVENT. THIS
JIVES WELL WITH THERMAL PROFILE EXPECTATIONS AND GIVEN THE LARGE
SCALE LIFTING PROFILE AND THE FACT THAT IT BISECTS THE DENDRITIC
GROWTH LAYER...PARTICULARLY ON MONDAY MORNING...A MODERATE
ACCUMULATING SNOW SEEMS LIKELY. WINTER WEATHER ADVISORIES HAVE
BEEN ISSUED HERE FOR SNOW FOR THE EVENT...THOUGH A PERIOD OF
MIXING WITH SLEET MAY BE POSSIBLE AS WELL.
WHILE THERE IS STILL A FAIR AMOUNT OF MODEL SPREAD FOR THIS
EVENT...THE FACT THAT COLD AIR HAS BEEN ENTRENCHED FOR SO LONG AND
WE HAVE SNOW COVER ALLOWS ENOUGH CONFIDENCE FOR HEADLINES TO BE
ISSUED. HOWEVER...IF THE COLDER GFS SOLUTION VERIFIES...SNOW
ACCUMULATIONS WILL LIKELY REPLACE THE ICE ACCUMULATIONS IN THE
FORECAST FOR SOME AREAS SOUTH OF I-80. THOSE AREAS IN PARTICULAR
SHOULD STAY ABREAST OF THE LATEST FORECAST UPDATES AS THE SYSTEM
UNFOLDS. ADDITIONALLY...TO THE SOUTHEAST IN THE CWA...A LATE ONSET
OF PRECIPITATION COMBINED WITH 850 MB TEMPERATURES CLIMBING AS
HIGH AS +5C WITH STRONGER WARM ADVECTION THROUGH THE EVENT REALLY
MAKE FORECASTING ICE PROBLEMATIC. DUE TO A LATER ONSET...HEADLINES
WERE NOT ISSUED FOR THIS AREA IN ORDER TO ALLOW FUTURE SHIFTS TO
FURTHER ANALYZE THE EVOLUTION OF THE SYSTEM AS IT NEARS.
HOWEVER...A PERIOD OF ICING EVEN HERE MAY BE POSSIBLE DEPENDING
UPON HOW WARM IT DOES GET THIS AFTERNOON AND WHETHER WARM
ADVECTION CAN BE OVERCOME BY WET BULB COOLING OVERNIGHT.
ALL AREAS SHOULD TRANSITION BACK TOWARD COLDER WEATHER BY MONDAY
AFTERNOON AS A COLD FRONT SLICES THROUGH THE AREA. THIS SHOULD END
THE THREAT OF ANY ADDITIONAL ICING ACROSS THE CWA. FRIES
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE BEGINNING TO SINK IN FROM THE NORTH MON NIGHT WILL
QUICKLY LOWER INVERSION HEIGHTS AND DRY OUT THE COLUMN...SHUTTING
DOWN PRECIPITATION CHANCES NORTH TO SOUTH THROUGH TUES MORNING. COLD
AND DRY NRLY FLOW WILL BRING 850MB TEMPS NEAR -10C ACROSS THE NORTH
TUES MORNING...WHILE THE SLIGHTLY WARMER AND MORE MOIST AIRMASS GETS
HUNG NEAR OUR SE RIDGES IN THE ZONAL FLOW ALOFT. THIS WILL SET UP A
FAIRLY STRONG GRADIENT OF CLOUDS AND TEMPERATURES NORTH TO SOUTH
ACROSS OUR CWA TUES AND EARLY WEDS. TUES MORNING TEMPS WILL RANGE
FROM THE LOW SINGLE DIGITS NORTH OF I-80 TO IN THE LOW 20S IN OUR
SRNMOST ZONES. WITH HIGH PRESSURE SETTLING IN ACROSS THOSE COLD NRN
AREAS...SFC FLOW IS EXPECTED TO BE FAIRLY LIGHT BUT WIND CHILL
VALUES DO APPROACH ADVISORY CRITERIA. THIS WILL NEED TO BE MONITORED
IN FURTHER UPDATES.
SRN MOISTURE IS RELUCTANT TO FULLY CLEAR THE SE RIDGES TUES NIGHT
AND ANOTHER WEAK UPPER LEVEL WAVE PUSHES THAT MOISTURE FURTHER NORTH
MIDDAY WEDS. ALTHOUGH MODEL SOLNS DIVERGE ON JUST HOW FAR THAT
MOISTURE RETURNS...WILL KEEP SLIGHT CHC SNOW IN FOR THE HIGHEST
ELEVATIONS. THE UPPER LEVEL WAVE EJECTS REMAINING MOISTURE WEDS
AFTERNOON...AND WITH HIGH PRESSURE FIRMLY IN CONTROL...A DRY MIDWEEK
CAN BE EXPECTED.
TAX
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
CONSIDERABLE MODEL AGREEMENT EXISTS IN THE EXTENDED AS THE
RELATIVELY DRY TREND IS EXPECTED TO CONTINUE INTO DAY 7 WITH NO
MAJOR SYSTEMS FORECAST. SFC HIGH PRESSURE WILL HOLD IN THE AREA THROUGH
THURS...KEEPING TWO WEAK SYSTEMS OUT OF THE FORECAST AREA WITH ONE
STREAMING WELL NORTH AND ANOTHER WELL TO OUR SOUTH. AN INCREASE IN
CLOUDS AND MAYBE A FEW LIGHT SNOW SHOWERS COULD DEVELOP ON THE SRN
TAIL OF THE NRN TRACK SYSTEM...BUT LITTLE ELSE IS EXPECTED.
TEMPERATURES WILL MODERATE CLOSER TO NORMALS THURS AND FRIDAY. SFC
HIGH WILL BUILD BACK IN TOWARDS THE END OF THE WORK WEEK. AS THE
AXIS OF THE HIGH SHIFTS EAST OF THE AREA NEXT WEEKEND SRLY FLOW WILL
BRING TEMPERATURES ABOVE AVERAGE.
TAX
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
GENERALLY CALM WINDS WITH A FEW HIGH CLOUDS OVERNIGHT WILL GIVE
WAY TO INCREASING SOUTHWESTERLY FLOW ON SUNDAY WITH BROKEN HIGH
CLOUDS CONTINUING. THE NEXT SYSTEM WILL APPROACH FROM THE
SOUTHWEST SUNDAY EVENING AND SPREAD A WINTRY MIX OF PRECIPITATION
OVER ALL THE SITES. PRECIPITATION TYPES SEEM LIKELY TO RANGE THE
FULL GAMUT...WITH SPECIFICS STILL LOW CONFIDENCE AS MODEL
SOLUTIONS VARY WILDLY. HOWEVER...DUE TO RECENT VERY COLD WEATHER
AND WARM ADVECTION ALOFT...IT WOULD SEEM AT LEAST SOME ICING IS
POSSIBLE OVERNIGHT AT MOST TERMINALS SAVE FOR THE FAR
NORTH...WHERE COLD AIR SHOULD REMAIN DEEP ENOUGH FOR ALL SNOW TO
FALL. FRIES
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
VFR CONDITIONS RETURN WITH HIGH PRESSURE MIDWEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR OHZ039>041-048-057.
FREEZING RAIN ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR OHZ049-050-058-059-068-069.
PA...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR PAZ013>016-020-022.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
MONDAY FOR PAZ007>009.
FREEZING RAIN ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR PAZ021-023-029-031-073>076.
WV...FREEZING RAIN ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
MONDAY FOR WVZ001>004-012.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1158 PM EST SAT JAN 10 2015
.AVIATION...
VFR CEILING ABOVE 5000 FEET WILL PERSIST THROUGH THE MORNING AND
THEN GIVE WAY TO HIGHER CLOUDS BEFORE THE NEXT LOW PRESSURE SYSTEM
ARRIVES SUNDAY NIGHT. RADAR RETURNS PROVED TO BE MOSTLY VIRGA DURING
THE EVENING AND WILL DIMINISH DURING THE REST OF THE NIGHT. MBS ALSO
REPORTED 1 HOUR OF MVFR CEILING DURING THE EVENING ON THE EDGE OF
THE LAKE CLOUD PLUME STREAMING INTO NORTHERN LOWER MICHIGAN. THAT IS
WHERE THE BULK OF MVFR CEILING WILL REMAIN THROUGH THE DAY. EXPECT
VFR TO PERSIST ALL AREAS UNTIL SNOW MOVES IN WITH THE NEXT SYSTEM
TOWARD SUNDAY EVENING. IFR RESTRICTION DOWN TO 1 MILE LOOKS LIKELY
WITH THIS PATTERN EXCEPT MBS BEING ON THE EDGE IS MORE LIKELY TO SEE
MVFR.
FOR DTW... MOSTLY VIRGA INDICATED BY RADAR DURING THE EVENING DID
MANAGE A 10SM -SN REPORT AT DTW...AND HELPED TAKE CEILING DOWN TO
5000 FT FOR A SHORT PERIOD. THIS MOISTURE WILL EXIT EASTWARD WITH A
VFR CEILING REBOUND ABOVE 5000 FEET THROUGH THE MORNING. SNOW IS
EXPECTED TO DEVELOP BY LATE AFTERNOON AND LAST THROUGH SUNDAY NIGHT.
IFR/LIFR RESTRICTION IS LIKELY AND MODERATE POTENTIAL FOR
ACCUMULATION IN THE 1-2 INCH RANGE.
//DTW THRESHOLD PROBABILITIES...
* HIGH PROBABILITY FOR SNOW AS PRECIPITATION TYPE SUNDAY NIGHT.
&&
.PREV DISCUSSION...ISSUED 334 PM EST SAT JAN 10 2015
SHORT TERM...TONIGHT
SE MICHIGAN WILL EASE INTO MORE OF A QUASI-ZONAL SLIGHTLY CONFLUENT
MID LEVEL FLOW TONIGHT...BASE OF THE PREDOMINANT CENTRAL CANADIAN
TROUGH DICTATING CONDITIONS RECENTLY FINALLY RELEASING NORTH AND
EAST. A TRANSITION TOWARD LOW LEVEL SOUTH-SOUTHWEST FLOW WILL
INITIATE THE EARLY STAGES OF A PERIOD OF WARM AIR ADVECTION THAT
WILL PERSIST THROUGH THE REMAINDER OF THE WEEKEND. VERY LIMITED
MOISTURE RETURN NOTED UPSTREAM THIS AFTERNOON WITHIN THE ENSUING
BROADENING ISENTROPIC ASCENT TIED TO THIS PROCESS. DESPITE THE
GENERAL WARMING THROUGH THE THERMAL PROFILE...THERE WILL REMAIN SOME
PERPETUATION OF THE ONGOING WEAK LAKE MOISTURE FLUX. THIS WILL
CONTRIBUTE SLIGHTLY TO THE OVERALL MOISTURE QUALITY NORTH OF THE I-
69 CORRIDOR... PROVIDING A WINDOW FOR SOME ADDITIONAL LIGHT SNOW
SHOWER DEVELOPMENT TONIGHT. ELSEWHERE LITTLE MORE THAN
FLURRIES...RECENT NAM AND RAP SOUNDING DATA STILL LEAVE A HEALTHY
DRY LAYER WITHIN THE LOWEST 4000 FT THROUGH THE NIGHT.
EXISTING ENVIRONMENT REMAINS FAVORABLE FOR A GOOD NOCTURNAL COOLING
RESPONSE THIS EVENING...PARTICULARLY SOUTHERN/CENTRAL SECTIONS WHERE
SKIES ARE NOW CLEAR. THIS WILL BRING LOWS IN MANY LOCALES INTO THE
SINGLE DIGITS EARLY TONIGHT. A THICKENING CLOUD DECK AND SOME
INCREASE IN THE SOUTHWEST GRADIENT WILL THEN ALLOW TEMPERATURES TO
RISE GRADUALLY HEADING INTO THE EARLY MORNING PERIOD. TEMPERATURES
BACK INTO LOW-MID TEENS BY DAYBREAK.
LONG TERM...
THE SQUEEZE PLAY LOOKS TO BE ON LATE TOMORROW/TOMORROW NIGHT AS
UPPER WAVE AND ASSOCIATED MOISTURE OVER TEXAS MAKES A RUN NORTHEAST
TOWARD THE CENTRAL GREAT LAKES. AT THE SAME TIME...ANOTHER STRONG
NORTHERN STREAM TROUGH WILL BE DROPPING SOUTHEAST FROM CENTRAL
CANADA. THE TROUGH AXIS IS DISTINCTLY POSITIVELY TILTED AND WILL ACT
TO SHUNT/SHEAR OUT THE WAVE TO OUR SOUTH. REASONABLE AGREEMENT WITH
SUFFICIENT MOISTURE TRANSPORT SNEAKING ACROSS THE MICHIGAN BORDER TO
SUPPORT SOME LIGHT SNOW...AS 850-700 MB SPECIFIC HUMIDITY OF 3+ G/KG
SEEN REACHING THE M-59 CORRIDOR (REGIONAL GEM/GFS) OR EVEN AS FAR
NORTH AS THE I-69 CORRIDOR (NAM). THERMAL PROFILES ARE NOT IDEAL FOR
HIGH SNOW TO LIQUID RATIOS HOWEVER. FORCING FROM ISENTROPIC ASCENT
PROSPECTIVE IS NOT VERY AGGRESSIVE...AND BEST 850 MB FGEN LOOKS TO
BE OCCURRING AT OR JUST SOUTH OF THE MICHIGAN BORDER. NOT MUCH OF A
SURFACE REFLECTION AS WELL. THIS APPEARS TO BE A 1 TO 2 INCH
SNOWFALL FOR MOST OF SOUTHEAST MICHIGAN (FOCUSED M-59 SOUTH) BY THE
TIME THE SNOW ENDS MONDAY MORNING. 925 MB TEMPS PROGGED TO RISE TO
AROUND -5 C...BUT BOUNDARY LAYER DEPTH WILL FAIL TO REACH THIS
LEVEL...AND A SLOW GRIND INTO THE 20S FOR HIGHS EXPECTED
TOMORROW...WITH TEMPS HOLDING NEARLY STEADY SUNDAY EVENING/NIGHT
WITH THE INCREASE IN MOISTURE AND SNOW. SURPRISINGLY...NORTHERN
STREAM TROUGH LOOKS TO BE PROVIDING ONLY A GLANCING BLOW WITH THE
COLD AIR...AS 850 MB TEMPS PROGGED TO DROP INTO MID NEGATIVE TEENS
(PER 12Z EURO)...WITH DRY AIR/SUBSIDENCE WINNING OUT AT THIS
LEVEL...WITH RH DROPPING BELOW 50 PERCENT. STILL...WITH LONG FETCH
NORTHERLY FLOW DEVELOPING OVER LAKE HURON ON MONDAY...ENOUGH COLD
AIR/INSTABILITY/SATURATION AT THE 925 MB LEVEL TO GENERATE SOME SNOW
SHOWERS...PROBABLY BRUSHING THE LAKE HURON SHORELINE...BUT THE
SHALLOW NATURE IS EXPECTED TO LIMIT THE INTENSITY. LOW LEVEL WINDS
EVEN BECOME LIGHT NORTHEAST/ONSHORE BY MONDAY EVENING...BUT AGAIN
WITH THE AMOUNT OF DRY AIR AROUND AND SHALLOW NATURE...SHOULD LIMIT
ACTIVITY TO SCATTERED LIGHT SNOW SHOWERS...WITH JUST LIGHT
ACCUMULATIONS EXPECTED OVER THE NORTHERN THUMB REGION.
SPLIT FLOW ALOFT AND STABLE COLD ANTICYCLONE AT THE SURFACE WILL
LEAD TO COLD AND DRY WEATHER TUESDAY AND WEDNESDAY. WITH SNOW PACK
AND LIGHT WINDS WE COULD SEE TEMPS TANK PRETTY WELL TUESDAY NIGHT
PROVIDED ENOUGH CLEARING TAKES PLACE. THE COLD AIRMASS BEGINS TO
SCOUR OUT A BIT THURSDAY AS SURFACE PRESSURE GRADIENT TIGHTENS AHEAD
OF INCOMING UPPER TROUGH. FRONTAL PASSAGE LATE THURSDAY COULD LEAD
TO A FEW LIGHT SNOW SHOWERS...BUT IT WILL BE MOISTURE STARVED SO
WILL KEEP POPS OUT FOR NOW. PROGRESSIVE NATURE OF THE TROUGH WILL
ALLOW RISING HEIGHTS AND WARM AIR ADVECTION FRIDAY WITH TEMPERATURES
POSSIBLY FINALLY APPROACHING NORMAL BY NEXT WEEKEND.
MARINE...
COLD SOUTHWEST FLOW OVER THE CENTRAL GREAT LAKES THIS AFTERNOON
LEADING TO SUSTAINED WINDS OF 20 TO 30 KNOTS OVER LAKE HURON AS THE
AREA IS SANDWICHED IN BETWEEN LOW PRESSURE OVER ONTARIO AND HIGH
PRESSURE ALONG THE OHIO RIVER. A MARGINAL GUST TO GALES REMAIN
POSSIBLE FOR ANOTHER FEW HOURS AND WILL EXTEND HEAVY FREEZING
WARNING INTO THE EVENING...BUT THE HIGH WILL BE SLOWING EXITING
EAST...ALLOWING THE PRESSURE GRADIENT TO RELAX AS WE HEAD INTO
TONIGHT AND ESPECIALLY TOMORROW...AS ANOTHER ARCTIC COLD FRONT
APPROACHES. THIS FRONT WILL SLIDE THROUGH TOMORROW NIGHT INTO
MONDAY...LEADING TO NORTHERLY WINDS OVER LAKE HURON. THE ARCTIC AIR
IN THE WAKE OF THIS FRONT WILL BE MORE SHALLOW...THUS REDUCING
MIXING DEPTHS...WITH GUSTS ONLY UP TO 30 KNOTS EXPECTED DURING
MONDAY. WINDS WILL DECREASE RAPIDLY MONDAY EVENING/NIGHT AS STRONG
HIGH PRESSURE SETTLES OVER THE ENTIRE GREAT LAKES REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
SHORT TERM...MR
LONG TERM....SF/DT
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1137 PM EST SAT JAN 10 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 320 PM EST SAT JAN 10 2015
A SLIGHT WARM UP IS ON THE WAY FOR THIS COMING WEEK. AS THE WARM
AIR STARTS TO MOVE IN TONIGHT THERE WILL BE A PERIOD OF LIGHT SNOW
SHOWERS...MOSTLY NORTH AND WEST OF GRAND RAPIDS. ANOTHER PERIOD OF
LIGHT SNOW WILL CROSS AREAS NEAR AND SOUTH OF INTERSTATE 96 SUNDAY
NIGHT AS THE COLD AIR ONCE AGAIN TRIES TO PUSH BACK SOUTHWARD. AS
OUR LAST POLAR ORIGIN HIGH OF THIS CURRENT WEATHER PATTERN MOVES
IN MONDAY SKIES WILL BE MOSTLY CLOUDY BUT WILL SEE CLEARING LATE
IN THE DAY. WITH THE HIGH OVERHEAD ON TUESDAY EXPECT MOSTLY SUNNY
SKIES AND VERY COLD TEMPERATURES FOR ONE MORE DAY. LOW WILL BE BELOW
ZERO IN MOST AREAS THAT NIGHT. BEY0ND THAT A SLOW WARM UP BEGINS. BY
NEXT SATURDAY WE MAY HAVE HIGH ABOVE FREEZING.
&&
.UPDATE...
ISSUED AT 951 PM EST SAT JAN 10 2015
WILL REDUCE POPS TO CHANCE OR SLIGHT CHANCE EVERYWHERE OVERNIGHT. A
LOT OF SHEAR IS SHOWING UP IN THE PROFILES WHICH IS REDUCING THE
LAKE ENHANCEMENT. ANY SNOW SHOULD REMAIN WITH LESS THAN AN INCH OF
ACCUMULATION POSSIBLE OVER PARTS OF THE NW CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 320 PM EST SAT JAN 10 2015
WE HAVE THE DEPARTING OF THE WEEK LONG COLD PATTERN UNDERWAY AS I
WRITE THIS. THIS WAS THE LONGEST STRING OF DAYS IN A ROW WITH
HIGHS BELOW 20 DEGREES IN GRAND RAPIDS SINCE THE MIDDLE OF
FEBRUARY IN 2007. THIS WILL BE HISTORY ON SUNDAY.
AS THE WARM AIR SURGES IN TONIGHT... EVEN WITH VERY FEEBLE
MOISTURE (PRECIPITABLE WATER SURGES TO A THIRD OF AN INCH/ 75TH
PERCENTILE)...SOME LIGHT SNOW IS EXPECTED WEST OF US-131 AND NORTH
OF GRAND RAPIDS DURING THE EARLY TO MID EVENING. THIS IS SHOWN BY
THE NAM... GFS... ECMWF... HRRR AND RAP MODELS TO VARYING DEGREES.
THERE IS A SURFACE BASED THERMAL BOUNDARY (20 DEGREE HOLLAND / 12AT
GRAND RAPIDS) CURRENTLY LOCATED FROM SOUTH HAVEN TO NEAR GRAND
RAPIDS TO NEAR MOUNT PLEASANT. THIS IS CURRENTLY FOCUSING SNOW
SHOWERS NEAR THE LAKE SHORE AND HELP FOCUS THE SNOW SHOWERS WITH
WARM AIR PUSH TONIGHT. ALSO HELPING THIS EVENT TOO IS THE LIFT
ASSOCIATED WITH THE ENTRANCE REGION TO DEPARTING UPPER LEVEL JET
CORE. THERE IS A 3 HOUR WINDOW WHERE OUR NORTHWEST CWA WILL HAVE
SOLID NEAR SATURATED AIR FROM AROUND 1000 FT AGL TO NEAR 10,000 FT
AGL. GIVEN HOW COLD IT IS...THAT IS MORE THAN ENOUGH TO LEAD TO
LIGHT SNOW SHOWERS.
ONCE THAT IS DONE SUNDAY NIGHT WE GET THE INTERPLAY OF THAT SAME
JET EXIT REGION WITH EXIT REGION OF JET CORE LIFTING NORTHWARD
FROM A SOUTHERN STREAM WAVE. THIS RESULTS IN A COUPLED JET AND THE
PRECIPITABLE WATER SURGES EVEN HIGHER TO NEARLY A HALF INCH WITH IS
ABOUT DOUBLE NORMAL. SO I AM THINKING LIGHT SNOW IS MORE THAN
LIKELY SOUTH OF INTERSTATE 96 SUNDAY NIGHT. IT IS MY EXPERIENCE
THAT THIS SORT OF EVENT NEARLY ALWAYS RESULTS IN MEASURABLE
PRECIPITATION SO I HAVE HIGH CONFIDENCE THERE WILL BE LIGHT SNOW
ALONG THE I-94 CORRIDOR SUNDAY NIGHT.
ONCE THAT IS DONE A JET CORE ON THE NORTHERN STREAM...DIVING DUE
SOUTHEAST FROM THE NORTHERN ARCTIC TOWARD HUDSON BY TUESDAY BRINGS
US OUR LAST SURGE OF VERY COLD AIR FOR TUESDAY. SINCE THE JET CORE
THIS TIME WILL BE WELL NORTH OF MICHIGAN THIS WILL BE SHALLOW COLD
AIR AND WINDS AT THE SURFACE WILL BE NORTHEAST SO WE GET TO SEE
MOSTLY SUNNY SKIES FOR A CHANGE! EVEN SO WITH SNOW ON THE GROUND
OVER MOST OF THE AREA IT WILL BE VERY COLD ONE LAST DAY.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT JAN 10 2015
THE LONG TERM PORTION OF THE FCST LOOKS TO BE VERY QUIET FOR THIS
TIME OF THE YEAR. WE WILL START OFF WITH A COLD MORNING AT THE
BEGINNING OF THE PERIOD...AND THEN MODERATE AT THE END OF THE PERIOD.
WE WILL SEE A VERY COLD MORNING TUE MORNING AND AGAIN ON TUE
NIGHT/WED MORNING. HIGH PRESSURE PROVIDING A LIGHT GRADIENT AND
MAINLY CLEAR SKIES...WILL COMBINE WITH OUR SNOW PACK TO ALLOW MOST
TEMPS TO DROP BELOW ZERO TUE MORNING AND WED MORNING.
SOME MODERATION IN TEMPS WILL TAKE PLACE FOR WED AND THU AS RETURN
FLOW FROM THE WSW WILL SET UP OVER THE AREA. HIGH PRESSURE WILL DROP
SOUTH...AND WE WILL EVENTUALLY SEE A COLD FRONT TRY TO APPROACH THE
AREA FROM THE NW. TOUGH TO TELL HOW FAR SOUTH THIS FRONT WILL MAKE
IT...BUT IT COULD BRING A LOW CHC OF SNOW TO THE NRN PORTION OF THE
AREA ON THU. THE FRONTAL POSITION WILL ALSO DICTATE HOW WARM WE GET.
THE GFS TAKES IT A BIT FURTHER SOUTH WHILE THE EURO HOLDS IT UP
NORTH OF THE AREA.
THE BEST MODERATION IN TEMPS WILL COME AT THE END OF THE PERIOD.
AFTER THE THU SYSTEM MOVES BY...WE WILL GET BACK INTO A RETURN FLOW
PATTERN ONCE AGAIN. A ZONAL FLOW ALOFT WILL KEEP THE COLD AIR AND
WAVES OF LOW PRESSURE FAR ENOUGH NORTH TO KEEP OUR AREA DRY. WE
SHOULD SEE TEMPS AT LEAST GET INTO THE 30S BY NEXT SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1137 PM EST SAT JAN 10 2015
VFR CONDITIONS SHOULD PREVAIL THROUGH SUNDAY ALTHOUGH THERE WILL
BE AREAS OF LIGHT SNOW AND CEILINGS IN THE 2500 TO 3000 FOOT
RANGE AT MKG AT TIMES TONIGHT. SOUTHWEST WINDS AROUND 10 KNOTS
THROUGH SUNDAY WITH SOME GUSTS OVER 20 KNOTS TONIGHT AT MKG.
&&
.MARINE...
ISSUED AT 320 PM EST SAT JAN 10 2015
I WILL ALLOW THE FREEZING SPRAY WARNING TO CONTINUE THROUGH 7 PM
AS WINDS ARE NEAR 25 KNOTS OVER THE WATER AND TEMPERATURES WERE IN
THE TEENS. SEEMS THAT TEMPERATURES WILL RISE INTO THE 20S IN THE
NEAR SHORE THIS EVENING ALLOWING US TO LET THE WARNING EXPIRE ON
TIME. WINDS WILL REMAIN STRONG ENOUGH FOR SMALL CRAFT INTO SUNDAY.
WE WILL HAVE TO WATCH TO SEE HOW MUCH THE ICE GROWS. THANKS TO
GLERL WE KNOW THERE IS ABOUT 22% ICE COVERAGE ON LAKE MICHIGAN NOW
AND THAT IF FORECAST TO INCREASE INTO THE MIDDLE OF NEXT WEEK.
&&
.HYDROLOGY...
ISSUED AT 320 PM EST SAT JAN 10 2015
LITTLE CHANGE SINCE YESTERDAY. CONTINUED THE FLOOD ADVISORY FOR THE
FLAT RIVER NEAR SMYRNA AS IT SHOULD REMAIN ABOVE BANKFULL INTO NEXT
WEEK. A COUPLE RIVERS REMAIN NEAR BUT UNDER BANKFULL AND WILL HAVE
TO BE MONITORED. FREEZE UP ICE JAMS MAY CAUSE FLUCTUATIONS IN RIVER
LEVELS INTO NEXT WEEK... BUT SERIOUS FLOODING IS NOT MUCH OF A
CONCERN UNTIL SNOWMELT AND ICE BREAKUP HAPPENS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...JK
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS
MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1156 PM CST Sat Jan 10 2015
.UPDATE:
Issued at 916 PM CST Sat Jan 10 2015
Temperatures have been slow to drop this evening due to southerly
winds and mid level clouds advecting northeastward through much of
the area, particularly southeast MO into southwest IL. The
operational models keep the precipitation out of our forecast area
until after 12Z Sunday. The latest HRRR model does bring some
light precipitation into our area already between 10-12Z Sunday,
but this is likely too early with an initially dry surface and
boundary layer. The precipitation may begin as sleet due to
evaporative cooling with very low surface dew points, but should
transition to freezing rain later in the morning with a pronounced
elevated warm layer.
GKS
&&
.SHORT TERM: (Through Late Tonight)
Issued at 333 PM CST Sat Jan 10 2015
The latest data suggests that the weather tonight should be rather
tranquil but seasonably cold. Heights aloft will be on the rise as
the eastern U.S. trof departs and short wave ridging increases ahead
of the lifting west TX upper low trof. In response the gradual
backing of the mid/upper level flow will allow clouds/moisture to
beginning spread into the area, especially overnight.
Glass
.LONG TERM: (Sunday through Next Saturday)
Issued at 333 PM CST Sat Jan 10 2015
Present indications are the winter weather event still remains on
track Sunday into Sunday night. Although the aforementioned
lifting upper low/trof will be weakening, it will spread weak
large scale ascent across the area Sunday into early Sunday
evening. This combined with ascent via low level warm advection
will allow precipitation to spread and develop northward from the
lower MS Valley into Missouri on Sunday morning. The primary
thrust will be across the southeast third of the CWA -
southeast/east central MO into southern IL. I am anticipating the
bulk of the precipitation to be in liquid form aka freezing rain.
Model soundings in this region show a deepening and strengthening
elevated warm layer, thus any sleet should occur in a small window
near the onset of the precipitation. Surface temperatures during
the day on Sunday will actually be warming in response to the low
level warm advection and will hover near freezing by mid-late
afternoon, however the speed at which this warming proceeds may be
hampered some by diabatic effects. Ground temperatures from the
recent Arctic blasts remain quite cold adding to the ice accretion
potential. Further north the precipitation coverage on Sunday as
well as the actual threat remains much more in question and pops
are only in the chance range. The elevated warm layer further
north is much weaker as well, allowing for a greater threat of
sleet should precipitation occur. Some of the guidance actually
suggests a narrow west-east warm advection band could quickly lift
northward across the northern half of the CWA but confidence at
this point is low.
The forecast for Sunday night is hardly clear cut. I think the main
thrust of warm advection precipitation will have exited the CWA to
the east or be close to exiting at 00Z Monday. However weak warm
advection will persist in the evening and a weak trailing vort max
will track across the area. We could see a band of light snow across
northern MO into central IL in association with ascent with the vort
max and mid level convergence/frontogenesis, while further south the
warm advection may contribute to very light freezing rain or freezing
drizzle.
Cumulatively this looks like a light event, with ice amounts of a
tenth of an inch or less in the most threatened region of southeast
and east central MO into southern IL. A winter weather advisory
has been hoisted in this area with the main impact being on travel
from ice accumulation on untreated roadways.
Clouds and cold advection dominate on Monday with a chance of snow
in the morning. The clouds should slowly clear north-south during
the day. Arctic high pressure but not as formidable as recent
systems will dominate the region Tuesday into Wednesday. A
progressive upper trof will move through the lower/mid MS Valley
late Wednesday with any precipitation threat looking to be to the
south of us at this time. In the wake of this trof the flow aloft
flattens and heights rise, leading to moderating temperatures the
later half of the week and into next Saturday.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1114 PM CST Sat Jan 10 2015
Complex fcst beyond 18Z Sunday. Prior to that expect a VFR
overcast with sthrly winds. Mdls indicate a narrow band of precip
lifting north thru MO and the sthrn half of IL Sunday mrng. Low
lvls remain rather dry so not sure any of this will reach the
ground and have not included this in the TAFs attm. Two areas of
precip dvlp/move into the region from late mrng thru the aftn. The
first area of precip will move into sthrn MO late mrng and then
on into e cntrl MO and sthrn IL drng the aftn. The STL metro sites
should be on the NW fringe of this area of precip. P-types will
also be a challenge as sfc temps are expected to hover near
freezing thru the day and a degree or two in either direction has
a significant effect on impacts. Have kept -FZRA going even though
fcst high temps are 32-34 degrees based on very cold grounds temps
due to recent cold temps. Bulk of the precip should exit east drng
the evng with -FZDZ remaining the rest of the night as addntl
upper lvl energy passes thru the region. The second batch of precip
is fcst to dvlp across nthrn MO ENE into SE IA and nthrn IL drng
the aftn. KUIN appears to be on the sthrn edge of this precip.
Soundings indicate colder conditions aloft further north so went
with a SN/PL mix though can`t rule out -FZRA/FZDZ mixing in drng
the aftn. This precip is fcst to continue into the overnight hrs and
should gradually transition to all snow after 6Z. KCOU may end up
too far west to be impacted by the larger area of precip to affect
the STL metro area and too far south to get in on the band of
sleet and snow to affect KUIN. If precip does occur at KCOU, it is
likely to be -RA/DZ drng the day as sfc temps are fcst to rise
into the mid 30s switching to -FZDZ drng the evng as sfc temps cool.
Have a low end MVFR CIG/VSBY fcst going Sunday night but fully
expect both elements to be IFR at some point drng the night.
Specifics for KSTL:
VFR conditions expected thru 18Z. Precip is expected to move into
the terminal drng the aftn with sfc temps near 32. Have -FZRA in
the TAF due to cold ground temps. If temps rise above 32 then
elevated sfcs will not experiencing icing effects. Bulk of the
precip moves out of the terminal drng the evng bcmng -FZDZ as air
temps drop below freezing. -FZDZ is expected to continue thru the
night possibly ending as a bit of light snow or flurries. Have a
low end MVFR fcst going but fully expect both IFR CIGs/VSBYs
Sunday night.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER WEATHER ADVISORY from 8 AM Sunday to 6 AM CST Monday FOR
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Lincoln MO-Madison MO-Osage MO-Reynolds MO-St. Charles MO-
St. Francois MO-St. Louis City MO-St. Louis MO-Ste.
Genevieve MO-Warren MO-Washington MO.
IL...WINTER WEATHER ADVISORY from 8 AM Sunday to 6 AM CST Monday FOR
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey
IL-Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
Randolph IL-St. Clair IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
301 AM CST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 253 AM CST SUN JAN 11 2015
THE FOCUS DURING THE SHORT TERM PERIODS WILL AGAIN BE CENTERED
AROUND CLOUDS AND TEMPERATURES. THE PATTERN ALOFT FEATURED
WESTERLY FLOW ACROSS OUR REGION WITH EMBEDDED WAVES IN THE FLOW.
ONE SUCH WAVE WAS TRANSLATING ACROSS KS...WHICH WILL HAVE LITTLE
CONSEQUENCE FOR OUR AREA. FARTHER NORTH ENERGY MOVING SOUTH FM
CANADA WAS MOVING SOUTH INTO THE NORTHERN PLAINS AND THIS WILL
SEND A REINFORCING COLD FRONT ACROSS THE PLAINS LATE THIS AFTN AND
TONIGHT.
CURRENT CONDITIONS AS OF 08Z PLACED A COOL FRONTAL BOUNDARY JUST
SOUTH OF THE PLATTE RIVER. TEMPERATURES BEHIND THE FRONT AVERAGED IN
THE SINGLE DIGITS AND TEENS WHILE AHEAD OF THE BOUNDARY READINGS
AVERAGED IN THE MIDDLE 20S. SO FAR FOG HAS YET TO FORM AND IF TRENDS
CONTINUE WILL REMOVE MENTION FOR THE EARLY MORNING HOURS.
WITH NO REAL PUSH OF THE FRONT TODAY...THE BOUNDARY IS ONLY EXPECTED
TO GRADUALLY SAG SOUTH INTO OUR SOUTHERN ZONES LATE THIS AFTN OR
EARLY EVENING. AHEAD OF THE FRONT TEMPS COULD EASILY BE QUITE
MILD IN THE 40S ACROSS MUCH OF KS...SIMILAR TO RAP DEPICTION BUT
THIS WILL ALSO BE DEPENDENT UPON CLOUD COVER. THE NAM IS ALSO ROBUST
WITH LLVL MOISTURE AND LOW CLOUDS LIFTING NORTH AHEAD OF THE
APPROACHING SHORTWAVE AND SURGES MOISTURE NORTH OF THE FRONT. THE
GFS KEEPS THE BRUNT OF THE CLOUDS SOUTH OF THE BOUNDARY. THE NAM
IS STILL SUFFERING FROM OVERZEALOUS SNOWPACK INITIALIZATION AND
LLVL MOISTURE FIELDS LIKELY DUE TO POTENTIAL SNOW MELT AND HAD TO
SHY AWAY FROM IT FOR THIS FORECAST. FOR THE FORECAST TODAY...HAVE
WENT WITH VARYING CLOUD COVER THRU THE FIRST PART OF THE AFTN WITH
TEMPS SIMILAR TO RAP WITH READINGS RANGING FROM THE UPPER 20S IN
OUR NORTHERN CWA (NORTH OF FRONT) TO TEMPS IN THE 40S ACROSS MUCH
OF NORTH CENTRAL KS (SOUTH OF BOUNDARY). CLOUD COVER WILL INCREASE
AND TEMPS COOL N/S WITH ARRIVAL OF SECONDARY COLD FRONT LATER THIS
AFTN AND TONIGHT.
CLOUD COVER WITH FRONT/WAVE WILL BE AT MID/HIGH LEVELS SO NOT
LOOKING FOR PCPN WITH THE SECONDARY COLD FRONT THIS EVENING/TONIGHT.
COLDER CONDITIONS WILL SETTLE IN DURING THE NIGHT AS A 1045 MB
SURFACE HIGH BUILDS SOUTH FM THE DAKOTAS. THE AIRMASS CHANGE IS A
DROP OF NEARLY 10C AT H85 FROM THIS MORNING TO MONDAY MORNING.
OVERNIGHT LOWS PRIMARILY IN THE SINGLE DIGITS COMBINED WITH A STEADY
NORTH WIND WILL PRODUCE WIND CHILLS BELOW ZERO BUT VALUES ARE NOT
LOOKING QUITE COLD ENOUGH FOR AN HWO MENTION ATTM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 253 AM CST SUN JAN 11 2015
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM LIE WITH
TEMPERATURES AND EARLY WEEK PRECIPITATION CHANCES.
MONDAY STILL ON TRACK TO BE THE COLDEST DAY OF THE FORECAST
PERIOD...WITH MODELS IN GOOD AGREEMENT SHOWING THE CWA BEING ON THE
SOUTHERN END OF AN UPPER LEVEL TROUGH AXIS EXTENDING BACK UP INTO
THE HUDSON BAY AREA. THIS TROUGH CONTINUES TO SWING THROUGH/EAST OF
THE CWA DURING THE DAYTIME HOURS MONDAY...WITH ZONAL TO SLIGHT NWRLY
FLOW BUILDING IN BEHIND. EVEN WITH THIS TROUGH SWINGING
THROUGH...MODELS NOT SHOWING AN ABUNDANCE OF MOISTURE AND CONTINUE
TO KEEP CONDITIONS DRY. THIS SYSTEM BRINGS A REINFORCING SHOT OF
NRLY WINDS AND COLDER AIR...SPEEDS ARE ONLY TOPPING OUT AROUND 10 TO
15 MPH IN THE MORNING...BUT WILL DIMINISH WITH TIME AS SFC HIGH
PRESSURE SETTLES FURTHER SOUTH. THE CENTER OF THE SFC HIGH REMAINS
OFF TO THE N/NE OF THE CWA...ENDING UP OVER FAR NERN NEB AT
00Z...THEN SHIFTS OVER TO THE CENTRAL PORTIONS OF THE IA/MN BORDER
BY TUESDAY MORNING...WHICH WILL BRING A GRADUAL TRANSITION IN WINDS
TO THE EAST THAN MORE SOUTHERLY BY 12Z TUESDAY. DID NOT MAKE NOTABLE
CHANGES TO INHERITED HIGHS FOR MONDAY...WHICH RANGE FROM THE LOWER
TEENS IN THE FAR NORTH TO LOWER 20S ACROSS NC KS. OVERNIGHT LOWS
MONDAY NIGHT/TUESDAY MORNING LOOK TO BOTTOM OUT IN THE SINGLE DIGITS
BELOW ZERO IN THE NORTHEAST TO NEAR 10 DEGREES IN THE FAR SW.
TUESDAY/TUESDAY NIGHT...MAIN STORY LIES WITH AN UPPER LEVEL
DISTURBANCE WHICH BY SUNRISE TUESDAY HAS DUG SOUTH INTO THE CENTRAL
ROCKIES/4 CORNERS REGION...WITH ZONAL FLOW IN PLACE ACROSS OUR AREA.
THROUGH THE DAYTIME HOURS...MODELS IN DECENT AGREEMENT SHOWING A
CLOSED CIRCULATION DEVELOPING OVER THE 4 CORNERS REGION...AND
TREKKING MAINLY EAST INTO THE TUESDAY NIGHT PERIOD...BUT ALSO
FILLING WITH TIME. THE 00Z ECMWF/GFS/GEM ARE ALL IN PRETTY GOOD
AGREEMENT SHOWING THE BRUNT OF THIS SYSTEM SLIDING TO THE SOUTH OF
THE CWA...BARELY GETTING CLIPPED BY THE NRN EDGE OF
PRECIPITATION...IF AT ALL. DISCOUNTED THE 00Z NAM...WHICH WAS
NOTABLY FURTHER NORTH AND DEEPER WITH THE SYSTEM...AND SHOWED SOME
LOCATIONS GETTING UPWARDS OF 4 INCHES OF SNOW. THE 06Z RUN HAS COME
MORE IN LINE WITH THE ECMWF/GFS/GEM. CONTINUED TO KEEP SOME 30-40
POPS CONFINED TO THE FAR S/SWRN PORTIONS OF THE CWA...WITH SOME 20
POPS BUFFERING THAT AREA TO THE NORTH. AT THIS POINT...IF SNOW DOES
MAKE IT FAR ENOUGH NORTH TO AFFECT OUR CWA...NOT EXPECTING MUCH IN
THE WAY OF ACCUMULATION. EXPECTING A BUMP UP IN TEMPS...WITH HIGHS
CURRENTLY FORECAST TO REACH THE LOWER 20S.
THROUGH THE REMAINDER OF THE LONG TERM PERIOD...WEDNESDAY THROUGH
SATURDAY...THE FORECAST CONTINUES TO BE A DRY ONE...WITH MODELS IN
DECENT AGREEMENT SHOWING NORTHWESTERLY FLOW DEVELOPING FOR WED/THURS
THANKS TO AT LEAST BRIEF RIDGING OVER THE WRN CONUS...BEFORE
BECOMING MORE ZONAL INTO FRI/SAT WITH AN APPROACHING DISTURBANCE
FROM THE NW. EXPECTING MODERATING TEMPERATURES ALOFT TO WORK THEIR
WAY IN FROM THE WEST...AND ALONG WITH THE POTENTIAL FOR MORE
DOWNSLOPING WRLY WINDS ESP THURS/FRI...TEMPS CLIMB A BIT EACH
DAY...AND ARE FORECAST BACK IN THE LOW/MID 40S CWA-WIDE FOR FRIDAY.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1048 PM CST SAT JAN 10 2015
A COLD FRONTAL BOUNDARY IS WORKING SOUTH OF THE TERMINALS AT THIS
HOUR AND WINDS WILL BE FROM A LIGHT NORTHERLY DIRECTION THRU THE
TAF PERIOD. NEXT CONCERN IS THE POTENTIAL FOR STRATUS AND OR FOG
DEVELOPMENT OVERNIGHT BUT MODELS STILL LOOK A BIT ROBUST ON THIS
COMPARED TO CURRENT OBSERVATIONS AND WILL MONITOR TRENDS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...ADP
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1221 AM CST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1221 AM CST SUN JAN 11 2015
LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH PUSHING SOUTH
INTO SOUTHERN ALBERTA/SASKATCHEWAN EARLY THIS MORNING. THE RIGHT
ENTRANCE REGION OF A 110KT 300MB JET WAS RESULTING IN LARGE SCALE
ASCENT PER 850-300MB OMEGA FIELD ACROSS WESTERN NORTH DAKOTA.
HOWEVER WITH A LACK OF A SURFACE FEATURE...THE OMEGA/VERTICAL MOTION
FIELD IS MORE OR LESS MAXIMIZED IN THE 700-500 LAYER PER LATEST TIME
HEIGHT CROSS SECTIONS. THIS IS FORECAST TO SLIDE EAST INTO SOUTH
CENTRAL NORTH DAKOTA BETWEEN 09Z AND 15Z SUNDAY. LATEST
RAP13/NAM/GFS/HRRR PRODUCE AN AREA OF LIGHT SNOW FROM KDIK TO KBIS
AND JUST SOUTH OF KJMS DURING OVERNIGHT. HAVE USED A BLEND OF THESE
SOLUTIONS TO INCREASE POPS OVER SOUTH CENTRAL NORTH DAKOTA
OVERNIGHT. EXPECTING ABOUT A HALF INCH IN THE SOUTHWEST TO THE
SOUTHERN BORDER...WITH AROUND TWO TENTHS FARTHER NORTH ALONG/NEAR
I-94. LATEST NAM/RAP13 BUFKIT SOUNDINGS SHOW THE OMEGA LAYER IS
CENTERED IN THE DENDRITIC GROWTH ZONE IN A SUPERSATURATED
ENVIRONMENT WITH RESPECT TO ICE...WITH THE FROST POINT EXCEEDING THE
TEMPERATURE PROFILE. BUT AS MENTIONED ABOVE...MAIN THING LACKING
FOR MORE INTENSE SNOWFALL DEVELOPMENT IS THERE IS NOTHING AT THE
SURFACE BEING REFLECTED TO ENHANCE CONVERGENCE...NO SIGNIFICANT
PRESSURE FALLS/NO SURFACE LOW/FRONT. ONCE THIS SHORTWAVE PASSES
BY...LARGE SCALE SUBSIDENCE TAKES CONTROL WITH A DISTINCT/SHARP
CLEARING LINE DEVELOPING IN THE NORTHWEST SUNDAY MORNING...AND
INTO SOUTH CENTRAL NORTH DAKOTA DURING THE EARLY AFTERNOON.
THE WIND CHILL ADVISORY IS HAVING A HARD TIME MEETING CRITERIA
EXCEPT IN THE TURTLE MOUNTAINS. WILL LET IT CONTINUE FOR NOW AND
REVISIT IT FOR THE NEXT FORECAST CYCLE. THE CLEARING LINE IS IN
SOUTHERN CANADA WHERE CURRENT WIND CHILL TEMPERATURES ARE 30 TO 36
BELOW ZERO...SO WE MAY ACTUALLY SEE BETTER VERIFICATION OF THE WIND
CHILL ADVISORY LATER SUNDAY MORNING AS CLOUDS DIMINISH AND
CLEARING SETS IN.
UPDATE ISSUED AT 923 PM CST SAT JAN 10 2015
MAIN CHANGE FOR LATE EVENING UPDATE WAS TO RAISE LOW TEMPERATURES
A BIT OVER THE NORTH CENTRAL AS CLOUD COVER HAS PUSHED WELL INTO
THE AREA. HAVE ALSO ADJUSTED POPS UP A LITTLE OVER THE
WEST...ALTHOUGH STILL SOME QUESTION ON HOW MUCH SNOW IF ANY WILL
MAKE IT TO THE GROUND WITH A RELATIVELY DRY LOWER ATMOSPHERE.
UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 625 PM CST SAT JAN 10 2015
PREVIOUS FORECAST WAS IN PRETTY GOOD SHAPE WITH ONLY CHANGE BEING
ADVANCING CLOUDS A LITTLE FASTER THAN PREVIOUSLY THOUGHT.
OTHERWISE...SNOW CHANCES CONTINUE FOR LATER THIS EVENING MAINLY
WEST INTO PORTIONS OF SOUTH CENTRAL. WILL KEEP AN EYE ON HOW THIS
EVOLVES OVER MONTANA TO SEE IF ANY CHANGES ARE NEEDED ON
SUBSEQUENT UPDATES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 301 PM CST SAT JAN 10 2015
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS SNOW CHANCES
WITH AN APPROACHING SHORTWAVE LATE TONIGHT THROUGH SUNDAY
MORNING...AND WIND CHILLS NORTH TONIGHT THROUGH MIDDAY SUNDAY.
A SHORTWAVE MOVING THROUGH MEAN WRN CANADA UPPER RIDGE CURRENTLY
MOVING FROM BRITISH COLUMBIA INTO ALBERTA...WILL COMBINE WITH A
NORTHERN STREAM SAVE DROPPING SOUTH FROM THE NORTHWEST TERRITORIES
AND MOVE INTO THE NORTHERN PLAINS LATE TONIGHT INTO SUNDAY. MID
LEVEL FORCING WILL PRODUCE A BAND OF LIGHT SNOW SPREADING FROM THE
LEE OF THE CANADIAN ROCKIES INTO EASTERN MONTANA THIS
EVENING...AND THEN ACROSS WESTERN NORTH DAKOTA AND INTO NORTHERN
SOUTH DAKOTA LATE TONIGHT THROUGH SUNDAY MORNING. THE TREND FROM
PREVIOUS RUNS HAS BEEN A LITTLE FARTHER NORTH WITH THE LIGHT
SNOW. HAVE UTILIZED BASICALLY A BLEND OF DETERMINISTIC GUIDANCE
WHICH BRINGS SLIGHT CHANCE TO CHANCE POPS MAINLY WEST AND SOUTH OF
LAKE SAKAKAWEA AND THE MISSOURI RIVER TONIGHT AND INTO THE FAR
SOUTH CENTRAL SUNDAY MORNING. THE LATEST MESOSCALE RAP AND HRRR
CONTINUE TO BRING THE BAND OF LIGHT SNOW EVEN A LITTLE FARTHER
NORTH...LIFTING NORTH AND EAST OF THE MISSOURI. WILL STICK WITH
THE CURRENT BLEND FOR NOW. SNOW AMOUNTS ARE EXPECTED TO BE LIGHT
WITH UNDER A HALF INCH...WITH POSSIBLY A HALF INCH TO AN INCH FROM
THE WEST CENTRAL INTO SOUTHWEST NORTH DAKOTA.
TO THE NORTH AND EAST...TEMPERATURES ARE IN THE SINGLE DIGITS
ABOVE ZERO ALONG THE CANADIAN BORDER...AND SHOULD DROP QUICKLY
THIS EVENING. WINDS WILL NOT BE STRONG BUT A STEADY 5 TO 10 MPH.
THIS WILL PRODUCE ADVISORY CRITERIA WINDS AGAIN LATE THIS EVENING
THROUGH SUNDAY MORNING ALONG THE CANADIAN BORDER. WILL ISSUE
ANOTHER ADVISORY TO COVER THIS.
SUNDAY WILL BRING TEMPERATURES SIMILAR TO TODAY WITH HIGHS FROM
NEAR ZERO NORTHEAST TO THE LOWER TEENS SOUTHWEST AND SOUTH
CENTRAL.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 301 PM CST SAT JAN 10 2015
COLD WITH DANGEROUS WIND CHILLS SUNDAY NIGHT...FOLLOWED BY A WARMING
TREND.
UPPER LEVEL NORTHWEST FLOW AND A LARGE SURFACE ARCTIC HIGH PRESSURE
SYSTEM WILL BE IN PLACE SUNDAY EVENING...WITH THE FORECAST CENTER OF
THE ARCTIC HIGH OVER SOUTHEASTERN SASKATCHEWAN/NORTHWESTERN
NORTH DAKOTA AROUND SUNSET SUNDAY EVENING. THE HIGH CENTER MOVES
SOUTHEAST ACROSS THE STATE SUNDAY NIGHT. BY DAYBREAK MONDAY MORNING
THE HIGH CENTER SHOULD BE OVER THE EASTERN DAKOTAS. NORTHWEST WINDS
SHOULD BE RATHER LIGHT - 5 TO 10 MPH SUNDAY EVENING AND UP TO 5 MPH
LATE SUNDAY NIGHT. LOW TEMPERATURES SHOULD BOTTOM OUT AROUND 15 TO
20 BELOW OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA. THE HIGH
CENTER SHOULD BE NORTH AND EAST OF THE SOUTHWESTERN PORTION OF THE
STATE...AND THERE THE OVERNIGHT LOWS SHOULD BE IN THE 10 TO 15 BELOW
ZERO RANGE. THESE MINIMUM TEMPERATURES COMBINED WITH THE WINDS UP TO
10 MPH AT TIMES WILL COMBINE TO PRODUCE WIND CHILLS IN THE 25 TO 30
BELOW ZERO RANGE (PERHAPS SOME ISOLATED LOCALES REACHING 35 BELOW
ZERO WIND CHILLS) FOR ALL BUT THE FAR SOUTHWESTERN COUNTIES OF NORTH
DAKOTA.
MONDAY AND MONDAY NIGHT: THE ARCTIC HIGH PRESSURE WILL CONTINUE
MOVING SOUTHEAST...AND THE UPPER LEVEL FLOW BEGINS CHANGING FROM
NORTHWEST TO A MORE ZONAL FLOW. LOOKING AT HIGHS MONDAY FROM JUST
ABOVE ZERO IN THE TURTLE MOUNTAINS AND JAMES RIVER VALLEY...TO THE
LOWER TEENS IN THE SOUTHWEST. LOWS WILL STILL BE BELOW ZERO MONDAY
NIGHT AS THE RESIDUAL ARCTIC AIR REMAINS OVER THE REGION.
THE CHANGING WEATHER PATTERN SHOULD BEGIN TO BE FELT ON TUESDAY AS
AN UPPER LEVEL RIDGE BEGINS BUILDING INTO THE WESTERN PLAINS...AND
AS SOUTHERLY SURFACE WINDS BEGIN TO BRING A MILDER PACIFIC AIRMASS
INTO THE REGION. LOOKING AT HIGHS TUESDAY IN THE TEENS AND LOWER 20S.
DRY CONDITIONS WILL CONTINUE AND TEMPERATURES WILL CONTINUE TO
MODERATE THROUGH THE WEEK AS PACIFIC RIDGING CONTINUES TO BUILD.
HIGHS ARE FORECAST TO BE AROUND AVERAGE (20S TO LOWER 30S) ON
WEDNESDAY...AND ABOVE AVERAGE (UPPER 20S TO MID/UPPER 30S) THURSDAY
THROUGH SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1221 AM CST SUN JAN 11 2015
A PERIOD OF LIGHT SNOW AND MVFR CIGS/VSBYS CAN BE EXPECTED AT
KDIK/KBIS THROUGH MID MORNING SUNDAY. KDIK WILL LIKELY HOLD ONTO THE
MVFR CIGS UNTIL MID AFTERNOON...WHILE KBIS WILL BEGIN TO SEE CIGS BY
15Z SUNDAY. THE REST OF THE TERMINALS WILL REMAIN VFR WITH A
CLEARING SKY COMMENCING DURING THE DAY SUNDAY FROM NORTHWEST TO
SOUTHEAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR NDZ002>005-011>013.
&&
$$
UPDATE...KS
SHORT TERM...TWH
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS TULSA OK
1128 PM CST SAT JAN 10 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
MVFR TO VFR CONDITIONS ARE CURRENTLY FOUND ACROSS EASTERN
OKLAHOMA AND WESTERN ARKANSAS. CONDITIONS WILL CONTINUE TO
DETERIORATE OVERNIGHT INTO SUNDAY...ESPECIALLY ACROSS SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS WHERE IFR CONDITIONS WILL BECOME
MORE COMMON.
&&
.PREV DISCUSSION... /ISSUED 934 PM CST SAT JAN 10 2015/
..UPDATE...
DISCUSSION...
UPPER WAVE CURRENTLY OVER FAR WEST TX WILL LIFT NORTHEASTWARD
ACROSS THE LOCAL REGION DURING THE DAY ON SUNDAY. PRECIPITATION
HAS BEGUN TO EXPAND ACROSS SOUTH CENTRAL TX AND THIS WILL SPREAD
NORTHEASTWARD OVERNIGHT AND THROUGH THE DAY ON SUNDAY. CURRENTLY
LOW LEVEL CONDITIONS REMAIN VERY DRY ACROSS THE AREA BUT WILL
MOISTEN AS PRECIPITATION INTENSITY INCREASES OVERNIGHT. SFC TEMPS
REMAIN THE LARGEST VARIABLE CONCERNING PRECIPITATION TYPE AS A
STOUT WARM LAYER ALOFT WILL ENSURE COMPLETE MELTING OF DROPLETS.
INITIAL PRECIP WILL LIKELY RESULT IN A BRIEF PERIOD OF WET BULB
COOLING HOWEVER SUSTAINED WARM ADVECTION ALONG WITH FURTHER
WARMING POTENTIAL WITHIN HEAVIER PRECIP BANDS SUGGESTS ANY COOLING
WILL BE BRIEF. THIS ALIGNS WILL ALL AVAILABLE HOURLY GUIDANCE SFC
TRENDS AND W/ THE EARLIER FORECAST THOUGHTS. THE END RESULT IS A
FZRA / RA MIX W/ LIMITED POTENTIAL FOR ICE ACCUMULATIONS. ELEVATED
SFCS AND THE MORE SHELTERED VALLEYS OF NW AR AND FAR SE OK WILL BE
MOST PRONE TO MEASURABLE ICE ACCUMULATIONS...AND EVEN THEN THE
AMOUNTS ARE EXPECTED TO REMAIN LIGHT.
THE UPDATED FORECAST WILL EXPAND HIGH PRECIP CHANCES ACROSS SE OK
PER CONSISTENT TRENDS IN HRRR DATA. OTHERWISE THE FORECAST IS
TRACKING WELL WITH MINIMAL ADJUSTMENTS NEEDED.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON SUNDAY FOR OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL NOON SUNDAY FOR ARZ002-ARZ011-
ARZ019-ARZ020-ARZ029.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1133 PM CST SAT JAN 10 2015
.UPDATE...
ISSUED AT 933 PM CST SAT JAN 10 2015
TEMPERATURES HAVE BEEN PROBLEMATIC THIS EVENING AS THEY HAVE
ACTUALLY RISEN THROUGH THE EVENING AHEAD OF A WEAK COLD FRONT
TRACKING EAST THROUGH NORTH CENTRAL WISCONSIN ON DOWN TO CENTRAL
IOWA. TEMPS ARE IN THE UPPER TEENS TO LOW 20S AHEAD OF THE FRONT
WHERE SOME 3-5KFT STRATUS IS HELPING TO KEEP THOSE TEMPERATURES
UP. SKIES CLEAR OUT ONCE THE FRONT COMES THROUGH AND THE
TEMPERATURES DROP INTO THE SINGLE DIGITS. 11.02Z RAP LOW LEVEL
MOISTURE FIELDS SHOW THIS AREA OF LOWER CLOUDS SHIFTING EAST OF
THE AREA SHORTLY AFTER MIDNIGHT. SO...LOW TEMPERATURES STILL
SHOULD BE HIT OVERNIGHT...IT JUST MAY TAKE A LITTLE LONGER TO GET
DOWN THERE.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 209 PM CST SAT JAN 10 2015
NORTHWEST FLOW ALOFT CONTINUES ACROSS THE REGION PER LATEST WATER
VAPOR/500 MB RAP ANALYSIS. A WEAK MID-LEVEL WAVE/SURFACE TROUGH
WITHIN THIS FLOW WAS DROPPING INTO THE DAKOTAS/MN THIS AFTERNOON
WITH DECENT WING OF 285-290K ISENTROPIC LIFT/WAA OUT AHEAD OF IT
INTO OUR AREA. THIS HAS RESULTED IN WIDESPREAD EXPANSION OF
ALTOCUMULUS/STRATOCUMULUS THROUGH THE DAY. NO SNOW FLURRY ACTIVITY
YET PER SURFACE OBSERVATIONS...BUT RADAR PICKING UP ON VIRGA AROUND
3KFT...SO EXPECTING AT LEAST A FEW FLURRIES GOING THROUGH THE REST
OF THIS AFTERNOON. OTHERWISE...TEMPERATURES ACROSS THE AREA THIS
AFTERNOON WERE IN THE SINGLE DIGITS/TEENS ABOVE ZERO.
LOOK FOR THE MID-LEVEL WAVE/SURFACE TROUGH TO CONTINUE SLIPPING
SOUTHEAST INTO THE REGION THIS EVENING...AND THEN EAST OF THE AREA
AROUND MIDNIGHT. WILL KEEP MENTION OF FLURRIES IN THROUGH THE
EVENING HOURS...MAINLY NORTHEAST OF I-94 BUT THEN DROPPED THEM AFTER
MIDNIGHT WITH FORCING EXITING THE AREA. OTHERWISE...LOOKS LIKE
SUBSTANTIAL MID-LEVEL CLOUD COVER WILL LINGER THROUGH THE OVERNIGHT
HOURS. AS A RESULT...TEMPERATURES ONLY EXPECTED TO DROP INTO THE
SINGLE DIGITS BELOW TO NEAR 10 ABOVE.
FOR SUNDAY AFTERNOON/EVENING...LOOKING AT ANOTHER WEAK MID-LEVEL
TROUGH DROPPING ACROSS THE REGION. NAM INDICATING DECENT AMOUNT OF
850-500MB FRONTOGENESIS WITH THE TROUGH AS IT DROPS SOUTHEAST ACROSS
THE AREA. BASED ON THIS SIGNAL...ADDED MENTION OF FLURRIES AS NAM
BUFKIT SOUNDINGS SHOWING ALMOST TOTAL COLUMN SATURATION. PLAN ON
HIGHS MOSTLY IN THE TEENS...WITH A FEW LOWER 20S ACROSS NORTHEAST IA
INTO FAR SOUTHWEST WI. NORTHWEST WINDS AND A PUSH OF ARCTIC AIR
OVERSPREAD THE AREA OVERNIGHT WITH LOWS DIPPING DOWN INTO THE SINGLE
DIGITS ABOVE AND BELOW ZERO. COMBINED WITH NORTHWEST WINDS AROUND 10
MPH...LOOKING FOR WIND CHILL VALUES IN THE TEENS TO NEAR 20 BELOW
ACROSS PARTS OF SOUTHEAST MN INTO NORTH CENTRAL WI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 209 PM CST SAT JAN 10 2015
COLD START TO THE NEW WORK WEEK AS MODIFIED ARCTIC AIRMASS MOVES
ACROSS THE REGION. PLAN ON HIGHS MONDAY AND TUESDAY IN THE SINGLE
DIGITS/TEENS ABOVE ZERO WITH LOWS MONDAY NIGHT IN THE SINGLE DIGITS
ABOVE AND BELOW ZERO.
LOOKING AT A SLOW WARMING TREND THEN FOR WEDNESDAY THROUGH SATURDAY
AS FLOW ACROSS THE CONUS BECOMES MORE HIGH ZONAL. THIS WILL TAP MORE
PACIFIC ORIGIN AIR INTO THE REGION WITH ARCTIC AIR RETREATING BACK
NORTH OF THE CANADIAN BORDER. MODEL CONSENSUS PRODUCES HIGH
TEMPERATURES WEDNESDAY IN THE TEENS TO LOWER 20S...THEN MODERATING
INTO THE UPPER 20S TO LOWER 30S BY FRIDAY AND SATURDAY. INCREASE IN
MID-LEVEL HEIGHTS/RIDGING KEEPS ANY WEATHER WELL NORTH OF THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1133 PM CST SAT JAN 10 2015
THE MVFR STRATUS DECK HAS SHIFTED OFF TO THE EAST OF LSE/RST WITH
SOME HIGH LEVEL CLOUDS MOVING IN FROM UPSTREAM. WINDS WILL REMAIN
ON THE LIGHT SIDE ON SUNDAY AS THE COLD FRONT STALLS OUT AND
DRIFTS EAST THROUGH THE DAY. THERE IS A FEATURE THAT APPEARS TO
MOVE IN TOMORROW EVENING WHICH COULD PRODUCE A VERY SHORT PERIOD
OF LIGHT SNOW. THE LOW LEVELS MAY BE TOO DRY FOR THIS SNOW TO
REACH THE GROUND...SO FOR NOW HAVE JUST ADDED A P6SM -SN TO THE
TAFS TOMORROW EVENING FOR WHEN IT LOOKS LIKE IT WILL SWING
THROUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM....DAS
LONG TERM.....DAS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1003 PM MST SAT JAN 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 136 PM MST SAT JAN 10 2015
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST PACKAGE IS THE
SNOW POTENTIAL INCREASING ACROSS THE AREA THIS EVENING AND SUNDAY AS
THE UPPER LEVEL WAVE MOVES TOWARD THE REGION.
TONIGHT-SUNDAY:
LATEST WATER VAPOR LOOP WAS SHOWING THE VORT LOBE
MOVING THROUGH SOUTHEAST OREGON. THIS FEATURE IS EXPECTED IS TO
TRANSLATE EAST THROUGH THE REGION TONIGHT AND SUNDAY. LATEST IR
LOOP WAS ALREADY SHOWING THE MOISTURE INCREASING ACROSS UTAH AND
LIFTING NORTHEAST. AT THIS POINT...IT APPEARS LIKE THE BEST CHANCE
OF SNOW WILL BE ACROSS THE MOUNTAINS DUE TO GOOD OROGRAPHICS AND
WEAK MID LEVEL JET STREAK. MEANWHILE...A WEAK BOUNDARY CURRENTLY
MOVING THROUGH NORTHERN MONTANA WILL INTERACT WITH THIS WAVE
TOMORROW AFTERNOON IN THE EASTERN PLAINS. THERE MAY BE ENOUGH
CONDITIONAL INSTABILITY TO PRODUCE A FEW AFTERNOON SNOW SHOWERS.
HOWEVER...IT WILL BE HIGHLY DEPENDENT ON HOW MUCH SUNSHINE CAN
OCCUR WITH COOLER TEMPERATURES ALOFT. AT THIS POINT...NOT REAL
CONFIDENT ABOUT THE SUNSHINE FACTOR TOMORROW...ESPECIALLY WITH ALL
OF THE CLOUD COVER CURRENTLY MOVING THROUGH IDAHO AND NEVADA. WE
DID RAISE SNOW CHANCES MAINLY IN THE NORTHERN PANHANDLE TOMORROW
AFTERNOON AS THE LOW LEVEL COLDER AIR MOVES INTO THE AREA CAUSING
THE LOW LEVEL THETA SURFACES (290-295K)TO RISE FAIRLY QUICKLY DUE
TO GOOD COLD AIR ADVECTION. THIS SNOW WILL SPREAD SOUTH DURING
LATE AFTERNOON INTO THE SOUTHERN PANHANDLE AND SOUTHEAST WYOMING.
AS A RESULT...WE RAISED SNOW CHANCES DURING THE EVENING.
OVERALL...NOT EXPECTING MUCH IN THE WAY OF ACCUMULATION WITH
SNOWFALL AMOUNTS GENERALLY AN INCH OR LESS IN THE EASTERN PLAINS
WITH GENERALLY 3-5 INCH AMOUNTS IN THE MOUNTAINS.
SUNDAY NIGHT-MONDAY:
ATMOSPHERE REMAINS FAIRLY SATURATED DURING THE EVENING INTO THE
OVERNIGHT HOURS...BUT THE UPPER LEVEL WAVE SHOULD BEGIN TO MOVE
OUT OF THE AREA BY THE EARLY SUNDAY EVENING. AS A RESULT...THIS
MAY RESULT IN SOME LINGERING LIGHT SNOW FLURRIES ALONG WITH SOME
PATCHY FOG. WE WERE NOT ENTIRELY CONFIDENT WITH THE FREEZING
DRIZZLE POTENTIAL AT THIS TIME...SINCE THE COLUMN STILL APPEARS TO
BE MOSTLY SATURATED. WE MAY DRY OUT A BIT ALOFT ON MONDAY
MORNING...BUT THE LIFT WILL ALSO BE QUITE MINIMAL. HOWEVER...WE
MAY HAVE TO KEEP AN EYE OUT ON THE CHEYENNE RIDGE DUE TO GOOD
UPSLOPE FLOW TRYING TO DEVELOP IN THE MORNING WHICH MAY RESULT IN
SOME PATCHY DENSE FOG. OTHERWISE...CHILLY CONDITIONS WILL PREVAIL
AS THE CANADIAN HIGH KEEPS ITS GRIP ON THE AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 136 PM MST SAT JAN 10 2015
MONDAY NIGHT...POSITIVELY TILTED SHORTWAVE TROUGH ALOFT TRACKS
ACROSS WESTERN WYOMING...EASTERN UTAH AND WESTERN COLORADO...WITH
THE NAM...GFS AND ECMWF KEEPING THE BULK OF THE SNOWFALL WITH THE
SHORTWAVE TROUGH...TO OUR SOUTH OVER COLORADO. ALTHOUGH THE 12Z NAM
DID SHOW MORE QPF OVER OUR FORECAST AREA...THAN DOES THE 18Z NAM OR
THE 12Z GFS AND ECMWF. WITH THIS TYPE OF TRACK THAT THE MODELS
INDICATE...WILL HAVE HIGH POPS...NEAR 100 PERCENT OVER THE HIGHER
PEAKS OF OUR SNOWY AND SIERRA MADRE RANGES...DUE TO DYNAMICS AND
OROGRAPHICS...WITH LOWER POPS NEAR THESE MOUNTAINS...AND FAR
SOUTHEAST WYOMING AND WESTERN NEBRASKA WILL LIKELY MISS OUT OF
MUCH OF THE MEASURABLE SNOWFALL EVENT.
TUESDAY...AFOREMENTIONED SHORTWAVE TROUGH ALOFT MOVES TO NORTHERN
NEW MEXICO BY SUPPERTIME...THOUGH WITH OROGRAPHIC SNOWS CONTINUING
ACROSS OUR SNOWY AND SIERRA MADRE RANGES...AND A FEW SNOW SHOWERS
NEARBY...AND DRY ELSEWHERE.
WEDNESDAY...BREEZY TO WINDY DAY ON TAP WITH NORTHWEST FLOW
ALOFT...AND DEEP UNIDIRECTIONAL NORTHWEST FLOW AT THE SURFACE AND
ALOFT...AND BASED ON THE PROGGED 700 MB GRADIENTS. MINIMAL LOW AND
MID LEVEL MOISTURE AND LACK OF LIFT SUGGESTS DRY WEATHER FOR ALL OUR
FORECAST AREA.
THURSDAY...WE EXPECT A DECENT WARMING TREND AS THE FLOW ALOFT BACKS
TO WEST...INDUCING OUR TYPICAL CHINOOK DOWNSLOPE WARMING AND SURFACE
LEE TROUGHING...AND IF THE OPACITY...THICKNESS...OF ANY MIDDLE AND
HIGH CLOUDS IS MINIMAL...EXPECT MAXIMUM TEMPERATURES TO SOAR WELL
INTO THE 30S ACROSS THE HIGHER VALLEY WEST OF INTERSTATE 25...AND
40S AND SOME 50S EAST OF I-25. PREFER THE WARMER GFS MEX MOS MAXIMA
OVER THE COOLER ECMWF MOS BASED ON THE SYNOPTIC PATTERN...EXPERIENCE
AND HOW MUCH DOWNSLOPE WARMING OFTEN ADDS TO THE POTENTIAL HIGH
TEMPERATURES.
FRIDAY...GFS AND ECMWF DIVERGE WITH THE 10/12Z ECMWF MAINTAINING
FAST WEST NORTHWEST FLOW ALOFT OVER OUR COUNTIES...WHEREAS THE
10/12Z GFS HAS BROAD TROUGHING ALOFT OVER OUR AREA. FOR
TEMPERATURES...THIS WOULD MAKE A SIGNIFICANT DIFFERENCE AND PREFER
THE WARMER GFS MOS MAX MAXIMA...AGAIN BASED ON EXPECTED SNOWMELT AND
WITH EXPERIENCE SEEING HOW MUCH DOWNSLOPE KATABATIC WARMING
DOES...ASSUMING MINIMAL OPACITY...THICKNESS...OF MIDDLE AND HIGH
CLOUDS.
SATURDAY...WITH ZONAL FLOW CONTINUING...ANOTHER DRY DAY ON TAP WITH
LIMITED LOW AND MID LEVEL MOISTURE AVAILABILITY. SLIGHTLY COOLER
TEMPERATURES ON TAP WITH MORE OPAQUE MIDDLE AND HIGH CLOUDS LIKELY
DOWNWIND OF FAST MOVING SHORTWAVE TROUGHS ALOFT TRAVERSING ACROSS
THE GREAT BASIN AND ROCKIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 959 PM MST SAT JAN 10 2015
EXPECT LOWERING CLOUDS OVER THE NEXT 24 HOURS AS A COLD FRONT
CURRENTLY IN MONTANA DROPS SOUTH AND LAYS UP AGAINST THE LARAMIE
RANGE BY LATE SUNDAY AFTERNOON. BEHIND THE FRONT...NORTHEAST
UPSLOPING WINDS WILL CREATE IFR/LIFR CONDITIONS WITH STRATUS AND
LIGHT SNOW THAT WILL CONTINUE INTO MONDAY. HRRR CONTINUES TO
SUGGEST LOWERING CONDITIONS AT KRWL TONIGHT...BUT GIVEN SIMILAR
CONDITIONS LAST NIGHT AND NOTHING HAPPENING...CONFIDENCE IS NOT
THERE TO BRING THEM DOWN.
&&
.FIRE WEATHER...
ISSUED AT 136 PM MST SAT JAN 10 2015
MINIMAL ISSUES DUE TO EXPECTED HUMIDITIES AND WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...REC
LONG TERM...RUBIN
AVIATION...GCC
FIRE WEATHER...REC
AREA FORECAST DISCUSSION...CORRECTED
NWS PHOENIX AZ
600 AM MST SUN JAN 11 2015
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE TO BE THE STORY THROUGH THE EARLY
PART OF THIS WEEK...AS A SERIES OF FAST MOVING TROUGHS CONTINUE TO
MOVE THROUGH THE DESERT SOUTHWEST. SHOWERS WILL ONCE AGAIN BE
POSSIBLE LATE TONIGHT INTO MONDAY MORNING...FOLLOWED BY A SLIGHT
CHANCE AGAIN EARLY TUESDAY. HIGH PRESSURE WILL RETURN TO THE AREA BY
MID WEEK WITH DRY WEATHER AND SLOWLY INCREASING TEMPERATURES
EXPECTED FROM WEDNESDAY INTO NEXT WEEKEND.
&&
.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY CONTINUES TO INDICATE AN ACTIVE
PATTERN ACROSS THE WESTERN CONUS. THE VERY WEAK TROUGH THAT BROUGHT
A FEW LIGHT RAIN SHOWERS TO THE REGION ON SATURDAY WAS BARELY
VISIBLE ACROSS NEW MEXICO...MEANWHILE A COMPACT UPPER LOW WAS
SPINNING UP WEST OF LOS ANGELES AND ANOTHER WEAKER SYSTEM WAS
LOCATED OFF THE WASHINGTON/OREGON COAST NEAR 45N/135W. ACROSS THE
REGION AS OF 0845Z THIS MORNING...CONDITIONS WERE MOSTLY DRY
ALTHOUGH REGIONAL RADAR IMAGERY SUGGESTED A FEW SHOWERS WERE TRYING
TO SPILL OVER THE COASTAL MOUNTAINS INTO JOSHUA TREE NATIONAL PARK.
TEMPS WERE GENERALLY IN THE LOWER 50S ACROSS THE DESERTS WITH NEARLY
CALM WINDS AT ALL SITES.
THE LOW TO THE WEST OF LOS ANGELES HAS BEEN WELL ADVERTISED FOR THE
PAST SEVERAL DAYS...HOWEVER IT WOULD SUBJECTIVELY APPEAR THAT IT IS
A BIT MORE INTENSE THAN THE 00Z MODELS INDICATED. 00Z NAM AND GFS
AND TO SOME EXTENT THE EUROPEAN DON`T INDICATE ANY PRECIPITATION
ACROSS SOUTHERN CALIFORNIA THIS MORNING AND THIS IS OBVIOUSLY
INCORRECT. HRRR AND HI-RES MODELS ARE ALSO STRUGGLING A BIT AT THE
MOMENT BUT THE PARALLEL GFS /13KM/ SEEMS TO HAVE A DECENT HANDLE ON
THE SITUATION AND APPEARS TO HAVE INITIALIZED THE BEST OF ANY
AVAILABLE MODEL. GFS13 SUGGESTS THE LOW WILL MOVE ONSHORE LATER THIS
MORNING WITH PRECIPITATION DEVELOPING OVER ARIZONA LATER THIS
AFTERNOON/EVENING AS IT TAPS INTO SOMEWHAT HIGHER MID/LOWER
TROPOSPHERIC MOISTURE. MODEL QPF OVER THE PAST FEW DAYS HAS NEVER
BEEN MUCH MORE THAN A FEW HUNDREDTHS TO A TENTH OF AN INCH ACROSS
THE DESERTS /CLOSER TO A QUARTER OF AN INCH EAST OF PHOENIX/ AND
THIS STILL HOLDS TRUE WITH TODAY`S 00Z MODELS /INCLUDING THE GFS13/.
LOOKS LIKE A HIGH POP...LOW QPF EVENT. BUMPED UP POPS QUITE A BIT
THIS EVENING AND OVERNIGHT FOR ARIZONA ALTHOUGH SOUTHEAST CALIFORNIA
MAY END UP MISSING OUT ON THE MAJORITY OF THE RAINFALL. TIMING IS
LARGELY UNCHANGED FROM WHAT I INHERITED /06Z-18Z MONDAY IS THE
PRIMARY TIME FOR RAIN CHANCES/.
SHOWERS WILL TAPER OFF QUICKLY MONDAY NIGHT YET MOISTURE WILL REMAIN
SOMEWHAT ELEVATED BEHIND THE DEPARTING TROUGH. ON ITS HEELS WILL BE
THE SYSTEM PRESENTLY WEST OF WASHINGTON/OREGON AS IT IS FORECAST TO
DIVE SOUTHWARD THROUGH THE GREAT BASIN AND INTO ARIZONA TUESDAY
MORNING. AS THERE WILL BE SOME MOISTURE IN PLACE AND THE COLD CORE
OF THE LOW WILL PASS SOMEWHAT CLOSE TO THE FORECAST AREA...I WILL
RETAIN AT LEAST A 20-30 POP EAST OF PHOENIX FOR TUESDAY/TUESDAY
AFTERNOON PER SREF AND NAEFS GUIDANCE. HOWEVER THE OVER-LAND
TRAJECTORY OF THIS TROUGH SHOULD MITIGATE WIDESPREAD PRECIPITATION
ACROSS THE REST OF THE AREA.
LOOKING AHEAD TO WEDNESDAY AND BEYOND...RIDGING WILL RETURN TO THE
AREA BUT NOT NEARLY TO THE EXTENT AS WAS SEEN A FEW DAYS AGO. THIS
SHOULD RESULT IN GRADUALLY INCREASING TEMPERATURES AND LITTLE TO NO
CHANCE OF PRECIPITATION ACROSS THE AREA. HIGHS WILL EVENTUALLY CREEP
BACK INTO THE MID 70S BY LATE WEEK/NEXT WEEKEND.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT INCREASING CLOUD COVER AND CIGS LOWERING TO AROUND 7KFT AT
TIMES AFTER 20Z THIS AFTERNOON...AND CONTINUING OVERNIGHT BEFORE
BECOMING SCATTERED AOA 9KFT LATE MONDAY MORNING. ORGANIZED SHOWERS
SHOULD HOLD OFF UNTIL LATER THIS EVENING/AFTER 04Z MONDAY. SURFACE
WINDS WILL REMAIN VERY LIGHT WITH PROLONGED PERIODS OF VARIABLE
DIRECTION THROUGH AT LEAST 12 MONDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
TUESDAY WILL SEE THE FINAL IN A SERIES OF TROUGHS MOVE THROUGH THE
AREA. LOOKS LIKE THE BEST CHANCE OF PRECIPITATION WILL BE IN THE
MOUNTAINS EAST OF PHOENIX. SHOWERS SHOULD TAPER OFF QUICKLY TUESDAY
NIGHT WITH DRY WEATHER FORECAST WEDNESDAY INTO THE WEEKEND. THERE
COULD ALSO BE SOME LOCALIZED BREEZINESS WITH THE TUESDAY SYSTEM
ESPECIALLY DOWN THE COLORADO RIVER AND ACROSS THE RIDGETOPS EAST OF
PHOENIX. NOTHING HIGH ENOUGH TO WARRANT ANY FIRE WEATHER HEADLINES
THOUGH. AS FOR MOISTURE...HUMIDITIES WILL DROP A BIT FROM MID WEEK
ONWARD YET AFTERNOON READINGS WILL ONLY DROP INTO THE 20-30 PERCENT
RANGE WITH GOOD OVERNIGHT RECOVERIES EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...MEYERS
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
724 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 724 AM MST SUN JAN 11 2015
MADE ADJUSTMENTS TO PRIMARILY NEAR-TERM GRIDS AS WELL AS SOME OF
THE SHORT-TERM GRIDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 355 AM MST SUN JAN 11 2015
FOR KALS...LOW CLOUDS AND AREAS OF DENSE FOG ARE EXPECTED INTO MID-
MORNING WITH CONDITIONS THEN IMPROVING BEFORE ANOTHER ROUND OF LOW
CLOUDS AND FOG DEVELOP AGAIN TONIGHT.
FOR KCOS AND KPUB...OTHER THAN SOME LOCALIZED LOW CLOUDS AND FOG
EARLY THIS MORNING...VFR CONDITIONS ARE ANTICIPATED TODAY BEFORE
CONDITIONS DETERIORATE BY TONIGHT IN THE WAKE OF A COLD FRONT MOVING
ACROSS SOUTHEASTERN COLORADO TODAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR COZ069>071.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
442 AM MST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 355 AM MST SUN JAN 11 2015
FOR KALS...LOW CLOUDS AND AREAS OF DENSE FOG ARE EXPECTED INTO MID-
MORNING WITH CONDITIONS THEN IMPROVING BEFORE ANOTHER ROUND OF LOW
CLOUDS AND FOG DEVELOP AGAIN TONIGHT.
FOR KCOS AND KPUB...OTHER THAN SOME LOCALIZED LOW CLOUDS AND FOG
EARLY THIS MORNING...VFR CONDITIONS ARE ANTICIPATED TODAY BEFORE
CONDITIONS DETERIORATE BY TONIGHT IN THE WAKE OF A COLD FRONT MOVING
ACROSS SOUTHEASTERN COLORADO TODAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM MST THIS MORNING FOR COZ069>071.
&&
$$
SHORT TERM...77
LONG TERM...28
AVIATION...77
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
816 AM CST SUN JAN 11 2015
.SHORT TERM...
325 AM CST
THROUGH MONDAY NIGHT...
UPPER LEVEL FLOW IS ZONAL WITH A SHORTWAVE TROUGH OVER TX. THE WAVE
WEAKENS AS IT MOVES OVER CENTRAL IL THIS EVENING. A SECOND SHORTWAVE
IS OVER THE DESERT SOUTHWEST AND IT WILL WEAKEN AS IT MOVES OVER THE
REGION MONDAY MORNING. AN UPPER LEVEL TROUGH IS STRETCHED OUT OVER
SOUTHERN CANADA AND IT/S TROUGH AXIS PASSES THROUGH THE REGION
MONDAY NIGHT.
A SURFACE HIGH IS OVER THE CENTRAL ATLANTIC COAST WHILE A WEAK
TROUGH/COLD FRONT STRETCHES FROM IOWA THROUGH SOUTHERN ONTARIO. THE
TROUGH/COLD FRONT WILL SAG SOUTH OVER THE CWA LATE THIS AFTERNOON
INTO THIS EVENING WHILE THE WEAK SURFACE LOW ASSOCIATED WITH THE
TROUGH SHIFTS NORTHEAST INTO SOUTHWEST QUEBEC. THE OTHER PLAYER IS
A LARGE HIGH PRESSURE SYSTEM CURRENTLY OVER SOUTHWEST CANADA WILL
SHIFT SOUTHEAST REACHING THE NORTHERN PLAINS TONIGHT BEFORE MOVING
OVER OUR NECK OF THE WOODS TUESDAY.
MOISTURE SURGES NORTH WITH THE FIRST SHORTWAVE TROUGH THIS AFTERNOON
AND EVENING. THERE SHOULD BE AMPLE LIFT FROM THE ON GOING WAA AND
ALONG THE TROUGH/COLD FRONT. GUIDANCE CONTINUES TO FEATURE A BAND
OF DECENT FRONTOGENESIS SINKING SOUTHEAST THROUGH THE CWA THIS
EVENING. THE NAM IS MORE EXCITED ABOUT THE FORCING THAN THE GFS.
THE NAM FEATURES A STRONG BAND STRETCHING FROM CHICAGO THROUGH LA
SALLE AT MIDNIGHT THAT QUICKLY SHIFTS SOUTHEAST TO A DETROIT MI TO
GIBSON CITY IL LINE BY 6AM MONDAY. THE GFS SHOWS A SIMILAR
PROGRESSION...JUST WEAKER. WHILE THE BAND IS IMPRESSIVE...OTHER
FACTORS SUCH AS EPV ARE MISSING SO I AM NOT EXCITED ABOUT INTENSE
BANDS OF SNOW. THAT BEING SAID...SOME ENHANCED BANDS OF SNOW MAY
FORM LEADING TO LOCALIZED HIGHER SNOW TOTALS.
PRECIP SPREADS NORTH THIS AFTERNOON WITH PRECIP FALLING SOUTH OF A
WAUKEGAN TO ROCKFORD LINE BY 6PM CST. EXPECTING SNOW FOR ALL AREAS
EXCEPT THOSE SOUTH OF A PONTIAC IL TO RENSSELAER INDIANA LINE.
SOUNDINGS SOUTH OF THIS LINE FEATURE PARTIAL MELTING ALOFT THAT MAY
LEAD TO SLEET MIXED WITH SNOW. NOT SURE HOW LONG SLEET OR A MIX OF
SLEET AND SNOW WILL FALL SOUTH OF THIS LINE AS COOLING MAY HELP THE
PRECIP TURN OVER TO ALL SNOW SOONER THAN FORECAST. IF THAT
HAPPENS...SNOW AMOUNTS WILL BE HIGHER THAN CURRENTLY FORECAST.
FOR THE AREAS NORTH OF THE PONTIAC TO RENSSELAER LINE...STEADY LIGHT
TO MODERATE SNOW IS EXPECTED THROUGH THE EVENING. A FEW BANDS OF
MODERATE TO POSSIBLY HEAVY SNOW MAY FORM ALONG AND SOUTH OF A
CHICAGO TO LA SALLE LINE AFTER MIDNIGHT. EXPECTING ALL SNOW ACROSS
THE CWA AFTER MIDNIGHT AND THE SNOW SLOWLY EXITS TO THE SOUTHEAST
THROUGH MID MONDAY MORNING.
HAVE LOWER STORM TOTAL SNOWFALL AMOUNTS THAN THE PREVIOUS FORECAST
DUE TO LESS CONFIDENCE IN BANDS OF HEAVIER SNOW AND HIGHER
CONFIDENCE IN SLEET MIXED WITH SNOW IN THE SOUTHERN CWA. EXPECTING
1 TO 2 INCHES ALONG AND SOUTH OF A OHARE TO AMBOY LINE WITH 1 TO
3...MAYBE LOCALIZED 4 INCHES SOUTH OF A GARY INDIANA TO LA SALLE
LINE.
WINDS TURN NORTH MONDAY LEADING TO THE POSSIBILITY OF LAKE EFFECT
SNOW OVER NW INDIANA MONDAY. STILL NOT OVERLY IMPRESSED WITH THE
LAKE EFFECT SET UP AS WELL WITH VERY MARGINAL DELTA T/S...DRY
FORECAST SOUNDINGS...AND SOME ICE OVER THE LAKE. AS SUCH CAPPED
POPS IN THE CHANCE RANGE. WINDS VEER TO NORTHEAST MONDAY EVENING
AND THE BAND OF SNOW SHIFTS WEST TO OVER ILLINOIS.
TEMPS MONDAY WILL VARY FROM THE MID TEENS OVER NORTH CENTRAL IL TO
THE MID 20S OVER NW INDIANA. LOWS WILL VARY FROM AROUND +10
DOWNTOWN TO 0 TO +5 IN OUTLYING AREAS. SOME ISOLATED LOCATIONS MAY
DIP BELOW ZERO.
JEE
&&
.LONG TERM...
325 AM CST
TUESDAY THROUGH SATURDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE CONUS TUESDAY WITH TROUGH
AXES/SHORTWAVES MOVING THROUGH THE REGION TUESDAY...WEDNESDAY AND
THURSDAY. THE SURFACE HIGH SITS OVER THE CWA TUESDAY AND SLOWLY
SINKS SOUTH WEDNESDAY. A CLIPPER SYSTEM PASSES TO OUR NORTH
WEDNESDAY NIGHT INTO THURSDAY WITH ANOTHER SURFACE HIGH MOVING OVER
THE REGION LATE IN THE WEEK.
LOOKING AT A DRY REST OF THE WEEK WITH HIGH TEMPS IN THE TEENS
TUESDAY AND WEDNESDAY. THEN WE GET INTO A WARMING TREND WITH AT OR
SLIGHTLY ABOVE FREEZING HIGH TEMPS BY THE END OF THE WEEK. THE ONLY
REALLY COLD NIGHT IS TUESDAY NIGHT WITH LOWS BETWEEN 0 AND -10 AWAY
FROM THE CITY BUT LIGHT WINDS WILL KEEP WIND CHILLS WARMER THAN
-20.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SNOW SPREADING NORTH/MOVING IN LATE THIS AFTERNOON/EARLY THIS
EVENING...ENDING OVERNIGHT.
* IFR VSBY WITH PERIODIC LIFR POSSIBLE IN VARIABLE BANDS OF SNOW.
CIGS LOWER TO MVFR/IFR THIS EVENING.
* SOUTH TO SOUTHWEST WINDS TURN NORTHWEST EARLY TONIGHT AND
INCREASE OUT OF THE NORTH MONDAY.
ED F
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS WILL CONTINUE THROUGH THE DAY BEFORE DETERIORATING
LATE THIS AFTERNOON AND THIS EVENING AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE REGION. SNOW WILL SPREAD NORTHWARD ACROSS THE
TERMINALS LATE THIS AFTERNOON THROUGH THE EVENING...THEN COME TO
AN END OVERNIGHT. RFD WILL LIKELY REMAIN JUST NORTH OF THE SNOW
BAND BUT WILL CONTINUE WITH A PROB30 MENTION FOR NOW.
OTHERWISE...SNOW MAY FALL IN SEVERAL BANDS WHICH SUGGESTS THAT
THERE MAY BE A HIGH DEGREE OF VARIABILITY IN CIGS AND ESPECIALLY
VSBY. SNOW WILL PROBABLY FALL CONTINUOUSLY FOR THE MOST PART BUT
INTENSITY MAY FLUCTUATE QUITE A BIT. HAVE GOOD CONFIDENCE IN THE
OVERALL TIME WINDOW FOR SNOWFALL BUT THE DETAILS SUCH AS
IDENTIFYING THE BEST WINDOW FOR LOWEST VSBY REMAINS A
CHALLENGE...TANKS TO THE TRANSIENT NATURE OF THE EXPECTED
BANDS. SOUTH TO SOUTHWEST WINDS WILL PREVAIL INTO THE EVENING AS
WELL BEFORE TURNING WEST THEN NORTHWEST TONIGHT BEHIND A FRONT.
MVFR CIGS MAY END UP PREVAILING INTO MONDAY MORNING BUT THERE IS
ALSO SUPPORT FOR LESS MVFR COVERAGE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN SNOW OCCURRING THIS EVENING. HIGH CONFIDENCE
IN START TIME. MEDIUM-HIGH CONFIDENCE IN END TIME.
* HIGH CONFIDENCE IN IFR VSBY OCCURRING IN SNOW WITH MEDIUM
CONFIDENCE IN LIFR VSBY OCCURRING INTERMITTENTLY. LOW CONFIDENCE
IN DURATION OF LIFR VSBY. HIGH CONFIDENCE IN CIG TRENDS THROUGH
THE EVENING. MEDIUM CONFIDENCE IN CIG TRENDS OVERNIGHT.
* HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS POSSIBLE. A CHANCE OF LIGHT SNOW SHOWERS. NORTH
WINDS.
TUESDAY...MVFR CIGS POSSIBLE. NORTHEAST-EAST WINDS.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR. SOUTHWEST TO WEST
WINDS.
MDB
&&
.MARINE...
254 AM CST
WEAK LOW PRESSURE IS MOVING ACROSS UPPER MICHIGAN THIS MORNING WITH
A TROUGH AXIS/COLD FRONT TRAILING IT TO THE SOUTHWEST. STRONG HIGH
PRESSURE OVER THE CAROLINA COAST WILL SHIFT OFFSHORE THROUGH THE DAY
ALLOWING THE SURFACE TROUGH TO SAG SOUTHEASTWARD INTO TONIGHT. THE
FAIRLY STRONG PRESSURE GRADIENT ACROSS LAKE MICHIGAN EARLY THIS
MORNING CONTINUES TO GENERATE STEADY WINDS BUT SPEEDS WILL STEADILY
DIMINISH THROUGH THE MORNING AS THE PRESSURE GRADIENT WEAKENS. WINDS
WILL SHIFT TO THE NORTHWEST TONIGHT AS THE FRONT PASSES WITH A
FURTHER SHIFT TO THE NORTH OCCURRING MONDAY MORNING. STRONG HIGH
PRESSURE ACROSS CENTRAL CANADA THIS MORNING WILL STRENGTHEN AS IT
MOVES SOUTHEAST INTO THE EASTERN DAKOTAS OVERNIGHT. AS A
RESULT...SPEEDS WILL PICK UP WITH GUSTS TO AROUND 25 KT LIKELY WITH
SOME CLOSER TO 30 KT POSSIBLE AT TIMES DURING THE DAY MONDAY BEFORE
WINDS TURN MORE TO THE NORTHEAST AND EASE MONDAY EVENING/NIGHT AS
THE HIGH SPREADS ACROSS THE LAKES.
THE HIGH WILL SHIFT SOUTH OF THE GREAT LAKES LATER WEDNESDAY. A
SERIES OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK ACROSS SOUTHERN
CANADA AND THE NORTHERN TIER OF STATES INTO LATE WEEK LEADING TO
PERIODIC WIND SHIFTS AND INCREASES IN SPEED.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
605 AM CST Sun Jan 11 2015
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 600 AM CST SUN JAN 11 2015
Timing of precip and precip type the main forecast concerns this
period. Next wave of low pressure will start to affect the area this
morning. The current VFR ceilings at 5-6K ft will thicken and
lower during the morning. Some light snow, sleet and freezing rain
are expected to develop across our southern TAF sites (KSPI, KDEC
and KCMI) in the 17z-19z time frame. DEC, SPI, and CMI could
transition to all freezing rain toward mid-afternoon as the warm
layer aloft increases temp to +3C. The northern TAF sites (KBMI
and KPIA) should remain a bit colder, seeing more of a light snow
and sleet mixture develop overhead between 18z- 20z. Once the
precip begins it will be just a matter of an hour or two before we
see cigs drop from low VFR to MVFR, and then IFR/LIFR after
21-22z. Forecast soundings suggest the higher probability for
freezing rain would be from SPI to DEC to near CMI with more of a
sleet and light snow mix further north at BMI, with mostly light
snow expected at PIA. Surface temperatures across our southern TAF
sites will warm to near the freezing mark but in all probability,
should begin to cool off by a degree or two after the precip
begins.
Look for the light wintry mix to continue on and off tonight with a
transition over to light snow as the night wears on due to a cold
front pushing acrs the area and cooling temps off just enough in
the lower levels of the atmosphere for the changeover to occur.
Surface winds will remain out of the south today with speeds of 8
to 12 kts. As the cold front approaches this evening, winds will
start to veer more into a westerly direction. Once the front
passes across the area between 04z-08z, winds will become N-NW and
remain generally less than 10kt through 12z/6am Monday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from Noon today to 9 AM CST Monday FOR
ILZ042>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
550 AM CST SUN JAN 11 2015
.SHORT TERM...
325 AM CST
THROUGH MONDAY NIGHT...
UPPER LEVEL FLOW IS ZONAL WITH A SHORTWAVE TROUGH OVER TX. THE WAVE
WEAKENS AS IT MOVES OVER CENTRAL IL THIS EVENING. A SECOND SHORTWAVE
IS OVER THE DESERT SOUTHWEST AND IT WILL WEAKEN AS IT MOVES OVER THE
REGION MONDAY MORNING. AN UPPER LEVEL TROUGH IS STRETCHED OUT OVER
SOUTHERN CANADA AND IT/S TROUGH AXIS PASSES THROUGH THE REGION
MONDAY NIGHT.
A SURFACE HIGH IS OVER THE CENTRAL ATLANTIC COAST WHILE A WEAK
TROUGH/COLD FRONT STRETCHES FROM IOWA THROUGH SOUTHERN ONTARIO. THE
TROUGH/COLD FRONT WILL SAG SOUTH OVER THE CWA LATE THIS AFTERNOON
INTO THIS EVENING WHILE THE WEAK SURFACE LOW ASSOCIATED WITH THE
TROUGH SHIFTS NORTHEAST INTO SOUTHWEST QUEBEC. THE OTHER PLAYER IS
A LARGE HIGH PRESSURE SYSTEM CURRENTLY OVER SOUTHWEST CANADA WILL
SHIFT SOUTHEAST REACHING THE NORTHERN PLAINS TONIGHT BEFORE MOVING
OVER OUR NECK OF THE WOODS TUESDAY.
MOISTURE SURGES NORTH WITH THE FIRST SHORTWAVE TROUGH THIS AFTERNOON
AND EVENING. THERE SHOULD BE AMPLE LIFT FROM THE ON GOING WAA AND
ALONG THE TROUGH/COLD FRONT. GUIDANCE CONTINUES TO FEATURE A BAND
OF DECENT FRONTOGENESIS SINKING SOUTHEAST THROUGH THE CWA THIS
EVENING. THE NAM IS MORE EXCITED ABOUT THE FORCING THAN THE GFS.
THE NAM FEATURES A STRONG BAND STRETCHING FROM CHICAGO THROUGH LA
SALLE AT MIDNIGHT THAT QUICKLY SHIFTS SOUTHEAST TO A DETROIT MI TO
GIBSON CITY IL LINE BY 6AM MONDAY. THE GFS SHOWS A SIMILAR
PROGRESSION...JUST WEAKER. WHILE THE BAND IS IMPRESSIVE...OTHER
FACTORS SUCH AS EPV ARE MISSING SO I AM NOT EXCITED ABOUT INTENSE
BANDS OF SNOW. THAT BEING SAID...SOME ENHANCED BANDS OF SNOW MAY
FORM LEADING TO LOCALIZED HIGHER SNOW TOTALS.
PRECIP SPREADS NORTH THIS AFTERNOON WITH PRECIP FALLING SOUTH OF A
WAUKEGAN TO ROCKFORD LINE BY 6PM CST. EXPECTING SNOW FOR ALL AREAS
EXCEPT THOSE SOUTH OF A PONTIAC IL TO RENSSELAER INDIANA LINE.
SOUNDINGS SOUTH OF THIS LINE FEATURE PARTIAL MELTING ALOFT THAT MAY
LEAD TO SLEET MIXED WITH SNOW. NOT SURE HOW LONG SLEET OR A MIX OF
SLEET AND SNOW WILL FALL SOUTH OF THIS LINE AS COOLING MAY HELP THE
PRECIP TURN OVER TO ALL SNOW SOONER THAN FORECAST. IF THAT
HAPPENS...SNOW AMOUNTS WILL BE HIGHER THAN CURRENTLY FORECAST.
FOR THE AREAS NORTH OF THE PONTIAC TO RENSSELAER LINE...STEADY LIGHT
TO MODERATE SNOW IS EXPECTED THROUGH THE EVENING. A FEW BANDS OF
MODERATE TO POSSIBLY HEAVY SNOW MAY FORM ALONG AND SOUTH OF A
CHICAGO TO LA SALLE LINE AFTER MIDNIGHT. EXPECTING ALL SNOW ACROSS
THE CWA AFTER MIDNIGHT AND THE SNOW SLOWLY EXITS TO THE SOUTHEAST
THROUGH MID MONDAY MORNING.
HAVE LOWER STORM TOTAL SNOWFALL AMOUNTS THAN THE PREVIOUS FORECAST
DUE TO LESS CONFIDENCE IN BANDS OF HEAVIER SNOW AND HIGHER
CONFIDENCE IN SLEET MIXED WITH SNOW IN THE SOUTHERN CWA. EXPECTING
1 TO 2 INCHES ALONG AND SOUTH OF A OHARE TO AMBOY LINE WITH 1 TO
3...MAYBE LOCALIZED 4 INCHES SOUTH OF A GARY INDIANA TO LA SALLE
LINE.
WINDS TURN NORTH MONDAY LEADING TO THE POSSIBILITY OF LAKE EFFECT
SNOW OVER NW INDIANA MONDAY. STILL NOT OVERLY IMPRESSED WITH THE
LAKE EFFECT SET UP AS WELL WITH VERY MARGINAL DELTA T/S...DRY
FORECAST SOUNDINGS...AND SOME ICE OVER THE LAKE. AS SUCH CAPPED
POPS IN THE CHANCE RANGE. WINDS VEER TO NORTHEAST MONDAY EVENING
AND THE BAND OF SNOW SHIFTS WEST TO OVER ILLINOIS.
TEMPS MONDAY WILL VARY FROM THE MID TEENS OVER NORTH CENTRAL IL TO
THE MID 20S OVER NW INDIANA. LOWS WILL VARY FROM AROUND +10
DOWNTOWN TO 0 TO +5 IN OUTLYING AREAS. SOME ISOLATED LOCATIONS MAY
DIP BELOW ZERO.
JEE
&&
.LONG TERM...
325 AM CST
TUESDAY THROUGH SATURDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE CONUS TUESDAY WITH TROUGH
AXES/SHORTWAVES MOVING THROUGH THE REGION TUESDAY...WEDNESDAY AND
THURSDAY. THE SURFACE HIGH SITS OVER THE CWA TUESDAY AND SLOWLY
SINKS SOUTH WEDNESDAY. A CLIPPER SYSTEM PASSES TO OUR NORTH
WEDNESDAY NIGHT INTO THURSDAY WITH ANOTHER SURFACE HIGH MOVING OVER
THE REGION LATE IN THE WEEK.
LOOKING AT A DRY REST OF THE WEEK WITH HIGH TEMPS IN THE TEENS
TUESDAY AND WEDNESDAY. THEN WE GET INTO A WARMING TREND WITH AT OR
SLIGHTLY ABOVE FREEZING HIGH TEMPS BY THE END OF THE WEEK. THE ONLY
REALLY COLD NIGHT IS TUESDAY NIGHT WITH LOWS BETWEEN 0 AND -10 AWAY
FROM THE CITY BUT LIGHT WINDS WILL KEEP WIND CHILLS WARMER THAN
-20.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* SNOW MOVING IN LATE THIS AFTERNOON/EARLY THIS EVENING...ENDING
OVERNIGHT.
* IFR VSBY WITH PERIODIC LIFR POSSIBLE IN SNOW. CIGS LOWER TO
MVFR/IFR THIS EVENING.
* SOUTH TO SOUTHWEST WINDS TURN NORTHWEST EARLY TONIGHT.
MDB
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS WILL CONTINUE THROUGH THE DAY BEFORE DETERIORATING
LATE THIS AFTERNOON AND THIS EVENING AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE REGION. SNOW WILL SPREAD NORTHWARD ACROSS THE
TERMINALS LATE THIS AFTERNOON THROUGH THE EVENING...THEN COME TO
AN END OVERNIGHT. RFD WILL LIKELY REMAIN JUST NORTH OF THE SNOW
BAND BUT WILL CONTINUE WITH A PROB30 MENTION FOR NOW.
OTHERWISE...SNOW MAY FALL IN SEVERAL BANDS WHICH SUGGESTS THAT
THERE MAY BE A HIGH DEGREE OF VARIABILITY IN CIGS AND ESPECIALLY
VSBY. SNOW WILL PROBABLY FALL CONTINUOUSLY FOR THE MOST PART BUT
INTENSITY MAY FLUCTUATE QUITE A BIT. HAVE GOOD CONFIDENCE IN THE
OVERALL TIME WINDOW FOR SNOWFALL BUT THE DETAILS SUCH AS
IDENTIFYING THE BEST WINDOW FOR LOWEST VSBY REMAINS A
CHALLENGE...TANKS TO THE TRANSIENT NATURE OF THE EXPECTED
BANDS. SOUTH TO SOUTHWEST WINDS WILL PREVAIL INTO THE EVENING AS
WELL BEFORE TURNING WEST THEN NORTHWEST TONIGHT BEHIND A FRONT.
MVFR CIGS MAY END UP PREVAILING INTO MONDAY MORNING BUT THERE IS
ALSO SUPPORT FOR LESS MVFR COVERAGE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN SNOW OCCURRING THIS EVENING. HIGH CONFIDENCE
IN START TIME. MEDIUM-HIGH CONFIDENCE IN END TIME.
* HIGH CONFIDENCE IN IFR VSBY OCCURRING IN SNOW WITH MEDIUM
CONFIDENCE IN LIFR VSBY OCCURRING INTERMITTENTLY. LOW CONFIDENCE
IN DURATION OF LIFR VSBY. HIGH CONFIDENCE IN CIG TRENDS THROUGH
THE EVENING. MEDIUM CONFIDENCE IN CIG TRENDS OVERNIGHT.
* HIGH CONFIDENCE IN WIND TRENDS.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS POSSIBLE. A CHANCE OF LIGHT SNOW SHOWERS. NORTH
WINDS.
TUESDAY...MVFR CIGS POSSIBLE. NORTHEAST-EAST WINDS.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR. SOUTHWEST TO WEST
WINDS.
MDB
&&
.MARINE...
254 AM CST
WEAK LOW PRESSURE IS MOVING ACROSS UPPER MICHIGAN THIS MORNING WITH
A TROUGH AXIS/COLD FRONT TRAILING IT TO THE SOUTHWEST. STRONG HIGH
PRESSURE OVER THE CAROLINA COAST WILL SHIFT OFFSHORE THROUGH THE DAY
ALLOWING THE SURFACE TROUGH TO SAG SOUTHEASTWARD INTO TONIGHT. THE
FAIRLY STRONG PRESSURE GRADIENT ACROSS LAKE MICHIGAN EARLY THIS
MORNING CONTINUES TO GENERATE STEADY WINDS BUT SPEEDS WILL STEADILY
DIMINISH THROUGH THE MORNING AS THE PRESSURE GRADIENT WEAKENS. WINDS
WILL SHIFT TO THE NORTHWEST TONIGHT AS THE FRONT PASSES WITH A
FURTHER SHIFT TO THE NORTH OCCURRING MONDAY MORNING. STRONG HIGH
PRESSURE ACROSS CENTRAL CANADA THIS MORNING WILL STRENGTHEN AS IT
MOVES SOUTHEAST INTO THE EASTERN DAKOTAS OVERNIGHT. AS A
RESULT...SPEEDS WILL PICK UP WITH GUSTS TO AROUND 25 KT LIKELY WITH
SOME CLOSER TO 30 KT POSSIBLE AT TIMES DURING THE DAY MONDAY BEFORE
WINDS TURN MORE TO THE NORTHEAST AND EASE MONDAY EVENING/NIGHT AS
THE HIGH SPREADS ACROSS THE LAKES.
THE HIGH WILL SHIFT SOUTH OF THE GREAT LAKES LATER WEDNESDAY. A
SERIES OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK ACROSS SOUTHERN
CANADA AND THE NORTHERN TIER OF STATES INTO LATE WEEK LEADING TO
PERIODIC WIND SHIFTS AND INCREASES IN SPEED.
MDB
&&
.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.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
342 AM CST Sun Jan 11 2015
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1105 PM CST SAT JAN 10 2015
Timing of precip and precip type the main forecast concerns this
period. Next wave of low pressure will start to affect the area on
Sunday bringing a thickening and lowering cig during the morning
with some light snow, sleet and freezing rain affecting our southern
TAF sites (KSPI, KDEC and KCMI) in the 17z-19z time frame, with
our remaining northern sites (KBMI and KPIA) seeing more of a light
snow and sleet mixture move in from 19z-21z. Once the precip begins
it will be just a matter of an hour or two before we see cigs drop
from low VFR to MVFR, and then IFR/LIFR after 00z. Forecast soundings
suggest the higher probability for freezing rain would be from SPI
to DEC to near CMI with more of a sleet and light snow mix further
north at BMI, with mostly light snow expected at PIA. Surface
temperatures across our southern TAF sites will warm to near the
freezing mark but in all probability, should begin to cool off by
a degree or two after the precip begins.
Look for the light wintry mix to continue on and off thru the night
with a transition over to light snow as the night wears on due to
a cold front pushing acrs the area and cooling temps off just enough
in the lower levels of the atmosphere for the changeover to occur.
Surface winds will remain out of the south thru the day Sunday with
speeds of 10 to 15 kts and then start to veer more into a westerly
direction late in the evening as a cold front approaches and then
passes across our forecast area during the overnight hours.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from Noon today to 9 AM CST Monday FOR
ILZ042>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Smith
AREA FORECAST DISCUSSION...CORRECTION
NWS NORTHERN INDIANA
1103 AM EST SUN JAN 11 2015
.SYNOPSIS...
ISSUED AT 555 AM EST SUN JAN 11 2015
A COLD FRONT DROPPING SOUTHEAST ACROSS THE GREAT LAKES WILL
COMBINE WITH A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST FROM THE
SOUTHERN PLAINS TO CAUSE SNOW TO OVERSPREAD OUR AREA FROM SOUTH
TO NORTH THIS AFTERNOON. THE SNOW WILL CONTINUE ACROSS THE AREA
TONIGHT BEFORE TAPERING OFF FROM NORTHWEST TO SOUTHEAST MONDAY
MORNING. SNOW MAY BE MIXED WITH SLEET SOUTH OF ROUTE 24. NEW SNOW
ACCUMULATIONS ARE EXPECTED TO BE 2 TO 4 INCHES... WITH HEAVIEST
AMOUNTS ALONG A KNOX INDIANA TO DEFIANCE OHIO LINE. HIGHS TODAY WILL
BE IN THE UPPER 20S AND LOWER 30S... WITH LOWS TONIGHT IN THE MID
20S.
&&
.UPDATE...
ISSUED AT 1057 AM EST SUN JAN 11 2015
ISSUED A WINTER WX ADVISORY FOR COUNTIES SE OF THE HWY 24 CORRIDOR
IN OH/IN AS 12Z NAM AND LAST SEVERAL HRRR CYCLES HAVE TRENDED A
LITTLE WARMER/NORTH WITH WARM LAYER ALOFT (1-3C) THIS EVENING/EARLY
OVERNIGHT. AS A RESULT ADDED IN SOME LIGHT ICING AND CHANCES FOR
FREEZING RAIN DURING THIS TIME. THIS IN ADDITION TO 2-3" OF
SNOW/SLEET WARRANTS THE HEADLINE. OTHERWISE...NO SIGNIFICANT CHANGES
MADE TO THE FCST INTO THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM EST SUN JAN 11 2015
VIGOROUS SRN STREAM DISTURBANCE OVR CNTRL TX WILL LIFT OUT NEWD INTO
CONFLUENT FLW ACRS THE LAKES AND PHASE W/DOMINANT NRN STREAM SW
AMPLIFYING THROUGH SE CANADA. POTENT LL MSTR SURGE READILY OBSVD IN
00Z RAOBS ACRS TX/OK AND XPCD TO RACE NEWD INTO THE LAKES BY EARLY
AFTN. ISENTROPIC CHARTS IMPRESSIVE TO SAY THE LEAST W/DEEP 4+ G/KG
MIXR NOTED COMMENSURATE W/ESCALATING PRES ADVTN FM 21-09Z BFR
TAILING OFF...AND NO DOUBT TIED TO JET COUPLING ALOFT BOTH LT THIS
AFTN AND OVERNIGHT.
WHILE SHEARING NATURE OF SRN STREAM SW WILL DAMPEN BACKGROUND
FORCING...FGEN RESPONSE AND ASSOCD BANDED PCPN SEEN IN MOST
INDIVIDUAL 00Z MODEL SOLUTIONS MORE THAN ADEQUATELY HINT OF THE
POTENTIAL FOR ONE OR MORE OVER PERFORMING SNOW BANDS TO FORM BOTH
THIS AFTN AND AGAIN THIS EVENING...EITHER OF WHICH MAY YIELD
SUBSTANTIALLY MORE SNOW THAN CURRENTLY INDICATED IN GRIDS ESP
THROUGH CNTR OF CWA. PRIMARY PROBLEM THOUGH IS EXACT LOCATION W/EACH
SOLUTION VARIED ENOUGH TO DAMPEN OUT NEEDED RESOLUTION W/A BLENDED
CONSENSUS QPF SIGNAL. REGARDLESS...BUMPED PRECIP OVR ALL AREAS
HIGHER. CORRESPONDING SNOW AMTS ARE A TAD HIGHER AS WELL W/AN
EXCEPTION ACRS THE FAR SOUTH WHERE WARM NOSE INTRUSION WILL YIELD A
PD OF SLEET THIS EVENING. THERMAL PROFILES ARE LACKING W/SIG WAA
ONGOING NOW THROUGH THIS AFTN W/SHALLOW HIGH CNTRD DGZ NOTED IN BUFR
SNDGS. HWVR CONCERN EXISTS ESP IN LIGHT OF HIGHER TRENDING QPF
SIGNALS AMONG MOST MODEL GUIDANCE. WILL DEFER HEADLINES IF ANY TO
THE DAY SHIFT TO SORT OUT W/HOPEFULLY BETTER ALIGNED 12Z GUIDANCE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM EST SUN JAN 11 2015
FLOW ALOFT TRENDING ZONAL ACROSS THE CONUS THIS WEEK SO A WARMUP IN
STORE... BUT WILL NEED TO ENDURE ONE MORE COLD SNAP BEFORE THEN AS A
SHALLOW ARCTIC AIRMASS MOVES INTO THE AREA BEHIND MONDAY`S CDFNT AND
THEN LINGERS THROUGH WED NGT AS HIGH PRESSURE MOVES SLOWLY SE FROM
THE NRN PLAINS ACROSS THE MIDWEST TUE-WED. WHILE TEMPS WILL BE WELL
BLO NORMAL IN THIS TIMEFRAME... WINDS WILL BE LIGHT SO COLD SHOULD
BE A LITTLE MORE TOLERABLE THAN PAST COUPLE OF COLD WAVES AND ATTM
DONT THINK ANY WIND CHILL HEADLINES WILL BE NEEDED THIS WEEK.
MAINTAINED GOING CATEGORICAL SNOW POPS ACROSS SE TAPERING TO LOW CHC
NW MONDAY MORNING AS FGEN FORCING ALONG H85 FRONT DROPS SE ACROSS
THE AREA WITH LINGERING MOIST AIRMASS IN PLACE. CONTD LOW SLR`S SE
WITH DEEP ISOTHERMAL NEAR FREEZING LAYER IN THIS AREA AND
HIGH/SHALLOW DGZ... FCST SNOW ACCUMS <1". DRY/SHALLOW ARCTIC AIRMASS
AND WINDS QUICKLY VEERING TO NNE MONDAY SUGGESTS LITTLE POTENTIAL
FOR POST-FRONTAL LAKE EFFECT... BUT DID MAINTAIN A LOW CHC IN THE
FAR NW IN THE AFTN. MODEST CAA SHOULD HOLD TEMPS NEARLY STEADY IN
THE 20S MONDAY... PLUMMETING TO AROUND ZERO MONDAY NIGHT AS SKIES
CLEAR AND WINDS DIMINISH. SHALLOW ARCTIC AIRMASS/WK LOW LEVEL MIXING
AS HIGH BUILDS INTO THE AREA TUE-WED SHOULD LIMIT DIURNAL TEMP RISES
WITH HIGHS ONLY 10-15 AND LOWS 0 TO -10. ZONAL FLOW ALOFT AND SW LOW
LEVEL FLOW LATE IN THE WEEK SHOULD RESULT IN A GOOD WARMUP WITH
TEMPS PRBLY A BIT ABOVE NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 555 AM EST SUN JAN 11 2015
MOISTURE STREAMING N-NE AHEAD OF SRN PLAINS SHRTWV SHOULD RESULT
IN GRADUAL LOWERING OF VFR CLOUD DECK TODAY... WITH IFR CONDITIONS
DVLPG THIS AFTN/EVE AS SNOW OVERSPREADS THE AREA FROM SOUTH-NORTH.
SNOW EXPECTED TO CONT OVERNIGHT AND THEN TAPER OFF AROUND DAYBREAK
MONDAY. MODEST SW WINDS WILL CONT TODAY... SHIFTING NW AROUND
DAYBREAK MONDAY AS A CDFNT MOVES SE ACROSS THE AREA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR INZ026-027-032>034.
MI...NONE.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR OHZ016-024-025.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...JT
SHORT TERM...T
LONG TERM...JT
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1057 AM EST SUN JAN 11 2015
.SYNOPSIS...
ISSUED AT 555 AM EST SUN JAN 11 2015
A COLD FRONT DROPPING SOUTHEAST ACROSS THE GREAT LAKES WILL
COMBINE WITH A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST FROM THE
SOUTHERN PLAINS TO CAUSE SNOW TO OVERSPREAD OUR AREA FROM SOUTH
TO NORTH THIS AFTERNOON. THE SNOW WILL CONTINUE ACROSS THE AREA
TONIGHT BEFORE TAPERING OFF FROM NORTHWEST TO SOUTHEAST MONDAY MORNING. SNOW
MAY BE MIXED WITH SLEET SOUTH OF ROUTE 24. NEW SNOW ACCUMULATIONS
ARE EXPECTED TO BE 2 TO 4 INCHES... WITH HEAVIEST AMOUNTS ALONG A
KNOX INDIANA TO DEFIANCE OHIO LINE. HIGHS TODAY WILL BE IN THE
UPPER 20S AND LOWER 30S... WITH LOWS TONIGHT IN THE MID 20S.
&&
.UPDATE...
ISSUED AT 1057 AM EST SUN JAN 11 2015
ISSUED A WINTER WX ADVISORY FOR COUNTIES SE OF THE HWY 24 CORRIDOR
IN OH/IN AS 12Z NAM AND LAST SEVERAL HRRR CYCLES HAVE TRENDED A
LITTLE WARMER/NORTH WITH WARM LAYER ALOFT (1-3C) THIS EVENING/EARLY
OVERNIGHT. AS A RESULT ADDED IN SOME LIGHT ICING AND CHANCES FOR
FREEZING RAIN DURING THIS TIME. THIS IN ADDITIONAL TO 2-3" OF
SNOW/SLEET WARRANTS THE HEADLINE. OTHERWISE...NO SIGNIFICANT CHANGES
MADE TO THE FCST INTO THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM EST SUN JAN 11 2015
VIGOROUS SRN STREAM DISTURBANCE OVR CNTRL TX WILL LIFT OUT NEWD INTO
CONFLUENT FLW ACRS THE LAKES AND PHASE W/DOMINANT NRN STREAM SW
AMPLIFYING THROUGH SE CANADA. POTENT LL MSTR SURGE READILY OBSVD IN
00Z RAOBS ACRS TX/OK AND XPCD TO RACE NEWD INTO THE LAKES BY EARLY
AFTN. ISENTROPIC CHARTS IMPRESSIVE TO SAY THE LEAST W/DEEP 4+ G/KG
MIXR NOTED COMMENSURATE W/ESCALATING PRES ADVTN FM 21-09Z BFR
TAILING OFF...AND NO DOUBT TIED TO JET COUPLING ALOFT BOTH LT THIS
AFTN AND OVERNIGHT.
WHILE SHEARING NATURE OF SRN STREAM SW WILL DAMPEN BACKGROUND
FORCING...FGEN RESPONSE AND ASSOCD BANDED PCPN SEEN IN MOST
INDIVIDUAL 00Z MODEL SOLUTIONS MORE THAN ADEQUATELY HINT OF THE
POTENTIAL FOR ONE OR MORE OVER PERFORMING SNOW BANDS TO FORM BOTH
THIS AFTN AND AGAIN THIS EVENING...EITHER OF WHICH MAY YIELD
SUBSTANTIALLY MORE SNOW THAN CURRENTLY INDICATED IN GRIDS ESP
THROUGH CNTR OF CWA. PRIMARY PROBLEM THOUGH IS EXACT LOCATION W/EACH
SOLUTION VARIED ENOUGH TO DAMPEN OUT NEEDED RESOLUTION W/A BLENDED
CONSENSUS QPF SIGNAL. REGARDLESS...BUMPED PRECIP OVR ALL AREAS
HIGHER. CORRESPONDING SNOW AMTS ARE A TAD HIGHER AS WELL W/AN
EXCEPTION ACRS THE FAR SOUTH WHERE WARM NOSE INTRUSION WILL YIELD A
PD OF SLEET THIS EVENING. THERMAL PROFILES ARE LACKING W/SIG WAA
ONGOING NOW THROUGH THIS AFTN W/SHALLOW HIGH CNTRD DGZ NOTED IN BUFR
SNDGS. HWVR CONCERN EXISTS ESP IN LIGHT OF HIGHER TRENDING QPF
SIGNALS AMONG MOST MODEL GUIDANCE. WILL DEFER HEADLINES IF ANY TO
THE DAY SHIFT TO SORT OUT W/HOPEFULLY BETTER ALIGNED 12Z GUIDANCE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM EST SUN JAN 11 2015
FLOW ALOFT TRENDING ZONAL ACROSS THE CONUS THIS WEEK SO A WARMUP IN
STORE... BUT WILL NEED TO ENDURE ONE MORE COLD SNAP BEFORE THEN AS A
SHALLOW ARCTIC AIRMASS MOVES INTO THE AREA BEHIND MONDAY`S CDFNT AND
THEN LINGERS THROUGH WED NGT AS HIGH PRESSURE MOVES SLOWLY SE FROM
THE NRN PLAINS ACROSS THE MIDWEST TUE-WED. WHILE TEMPS WILL BE WELL
BLO NORMAL IN THIS TIMEFRAME... WINDS WILL BE LIGHT SO COLD SHOULD
BE A LITTLE MORE TOLERABLE THAN PAST COUPLE OF COLD WAVES AND ATTM
DONT THINK ANY WIND CHILL HEADLINES WILL BE NEEDED THIS WEEK.
MAINTAINED GOING CATEGORICAL SNOW POPS ACROSS SE TAPERING TO LOW CHC
NW MONDAY MORNING AS FGEN FORCING ALONG H85 FRONT DROPS SE ACROSS
THE AREA WITH LINGERING MOIST AIRMASS IN PLACE. CONTD LOW SLR`S SE
WITH DEEP ISOTHERMAL NEAR FREEZING LAYER IN THIS AREA AND
HIGH/SHALLOW DGZ... FCST SNOW ACCUMS <1". DRY/SHALLOW ARCTIC AIRMASS
AND WINDS QUICKLY VEERING TO NNE MONDAY SUGGESTS LITTLE POTENTIAL
FOR POST-FRONTAL LAKE EFFECT... BUT DID MAINTAIN A LOW CHC IN THE
FAR NW IN THE AFTN. MODEST CAA SHOULD HOLD TEMPS NEARLY STEADY IN
THE 20S MONDAY... PLUMMETING TO AROUND ZERO MONDAY NIGHT AS SKIES
CLEAR AND WINDS DIMINISH. SHALLOW ARCTIC AIRMASS/WK LOW LEVEL MIXING
AS HIGH BUILDS INTO THE AREA TUE-WED SHOULD LIMIT DIURNAL TEMP RISES
WITH HIGHS ONLY 10-15 AND LOWS 0 TO -10. ZONAL FLOW ALOFT AND SW LOW
LEVEL FLOW LATE IN THE WEEK SHOULD RESULT IN A GOOD WARMUP WITH
TEMPS PRBLY A BIT ABOVE NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 555 AM EST SUN JAN 11 2015
MOISTURE STREAMING N-NE AHEAD OF SRN PLAINS SHRTWV SHOULD RESULT
IN GRADUAL LOWERING OF VFR CLOUD DECK TODAY... WITH IFR CONDITIONS
DVLPG THIS AFTN/EVE AS SNOW OVERSPREADS THE AREA FROM SOUTH-NORTH.
SNOW EXPECTED TO CONT OVERNIGHT AND THEN TAPER OFF AROUND DAYBREAK
MONDAY. MODEST SW WINDS WILL CONT TODAY... SHIFTING NW AROUND
DAYBREAK MONDAY AS A CDFNT MOVES SE ACROSS THE AREA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR INZ026-027-032>034.
MI...NONE.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR OHZ016-024-025.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...JT
SHORT TERM...T
LONG TERM...JT
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
900 AM CST SUN JAN 11 2015
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 900 AM CST SUN JAN 11 2015
WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE A WEAK UPPER LEVEL
SHORTWAVE TROUGH LIFTING NORTHEASTWARD ACROSS THE CENTRAL PLAINS
THIS MORNING. MEANWHILE, ANOTHER WEAK UPPER LEVEL SHORTWAVE IS
PUSHING ASHORE INTO SOUTHERN CALIFORNIA. NEAR THE SURFACE, A LEE
SIDE TROUGH OF LOW PRESSURE IS SITUATED NEAR AND ALONG THE COLORADO
BORDER WHILE A COLD FRONT IS SINKING SOUTHWARD ACROSS THE NORTHERN
PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST SUN JAN 11 2015
OTHER THAN POTENTIAL FOR FOG DEVELOPMENT LATER THIS MORNING, THE
SHORT TERM FORECAST IS ONE OF FAIRLY BENIGN WEATHER. SOMEWHAT
RELATIVE UNCERTAINTY EXISTS WITH RESPECT TO TEMPERATURES AT LEAST
THIS AFTERNOON AS WELL. THE WEAK COLD FRONT POISED TO MOVE INTO THE
AREA LATER TONIGHT WAS POSITIONED ACROSS NORTHWEST KANSAS INTO
EASTERN NEBRASKA. LIGHT SOUTHWEST WILL PERSIST AHEAD OF THIS SURFACE
FEATURE TODAY. ALREADY THIS MORNING, THE DEW POINT DEPRESSIONS HAVE
FALLEN TO ONE TO THREE DEGREES AT LOCATIONS LIKE SCOTT CITY, TO
SYRACUSE AND GARDEN CITY, WHERE THE NAM WAS MOST PRONOUNCED IN
DEVELOPING FOG. THE MODEL TREND WAS TO DEVELOP THIS SURFACE
RADIATION FOG BETWEEN AROUND 11 TO 14 Z BEFORE AN
INSOLATION/VERTICAL MIXING INDUCED DISSIPATION. TEMPERATURES FOR THIS
AFTERNOON WILL ALSO BE A CHALLENGE AS THE MID LEVEL CLOUDS NOW
INCREASING ACROSS SOUTH CENTRAL KANSAS WILL INHIBIT INSOLATION AND
RESULTANT SURFACE HEATING LATER IN THE MORNING. TEMPERATURES WILL BE
WARMEST IN THE WEST THIS AFTERNOON. THE COLD FRONT WILL PLUNGE
THROUGH WESTERN KANSAS AROUND 00 UTC AS A MID LEVEL WAVE SHIFTS INTO
EASTERN KANSAS THIS EVENING. THE MODELS AND MOS OUTPUT INDICATE A
HIGH LEVEL OF AGREEMENT ON LOWS OVERNIGHT IN THE LOW SINGLE DIGITS
CWA-WIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CST SUN JAN 11 2015
MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH AN UPPER LEVEL
TROUGH, LOCATED AROUND 50N 140W AT 00Z SUNDAY, MOVING ACROSS THE
NORTHWESTERN UNITED STATES ON MONDAY. BY 12Z TUESDAY THIS UPPER
LEVEL SYSTEM WILL BE LOCATED AROUND THE FOUR CORNERS REGION. AS
THIS NEXT SYSTEM MOVES INTO THE FOUR CORNERS REGION ON MONDAY A
SURFACE RIDGE AXIS WILL BE CROSSING CENTRAL KANSAS AND MID TO HIGH
LEVEL MOISTURE WILL BEGIN TO SPREAD ACROSS WESTERN KANSAS. BASED
ON THE INCREASING CLOUD COVER AND NORTHEAST/EASTERLY FLOW OF COLD
AIR IN THE LOWER LEVELS ADVECTING INTO WESTERN KANSAS THE PREVIOUS
FORECAST STILL LOOKS ON TRACK WITH HIGHS MAINLY IN THE LOW TO MID
20S.
MONDAY NIGHT AND TUESDAY THE SURFACE WINDS WILL GRADUALLY VEER TO
THE SOUTH/SOUTHEAST AS THE SURFACE HIGH SLIDES EAST TOWARDS THE
MISSISSIPPI VALLEY. AS THE SOUTH/SOUTHEASTERLY FLOW DEVELOPS THE
0-1KM AGL DEWPOINTS WILL BEGIN TO SLOWLY INCREASE ACROSS FAR
WESTERN/SOUTHWEST KANSAS AND WARM AIR ADVECTION WILL BEGIN TO
DEVELOP. 800MB TO 500MB MOISTURE IS ALSO FORECAST TO CONTINUE TO
INCREASE ACROSS THE CENTRAL HIGH PLAINS AS THE UPPER LEVEL TROUGH
MOVES EAST TOWARDS THE CENTRAL ROCKIES. AT THIS TIME PRECIPITATION
CHANCES THROUGH MID DAY ON TUESDAY APPEARS SMALL GIVEN THE LIMITED
LOW LEVEL MOISTURE AND LIFT, EVEN FROM THE MORE AGGRESSIVE NAM AND
ECMWF. BY TUESDAY AFTERNOON SOME LIGHT SNOW WILL BE POSSIBLE
ACROSS PORTIONS OF WESTERN GIVEN THE INCREASING MOISTURE AND LIFT
IN THE 900MB TO 800MB LEVEL FROM THE NAM AND ECMWF. THIS
PRECIPITATION WILL THEN SPREAD NORTH AND EAST THROUGH THE
OVERNIGHT HOURS AS 700MB FRONTOGENESIS IMPROVES AHEAD OF THE UPPER
LEVEL TROUGH/LOW WHICH WILL BE MOVING EAST ACROSS NEW MEXICO AND
COLORADO TUESDAY NIGHT. CONFIDENCE ON SNOWFALL AMOUNTS STILL
REMAIN LOW ACROSS WESTERN KANSAS THIS MORNING GIVEN THE CURRENT
DISCREPANCIES BETWEEN THE MODELS CONCERNING MOISTURE AND LIFT,
EVEN WITH THE ENHANCED LIFT FROM THE 700MB FRONTOGENISIS WHICH
WILL BE CROSSING WESTERN KANSAS DURING THE OVERNIGHT HOURS.
BY EARLY WEDNESDAY THE MOISTURE AND LIFT AHEAD OF THE UPPER LEVEL
TROUGH APPEARS TO BE CONFINED TO PORTIONS OF SOUTH CENTRAL KANSAS.
THIS IS FORECAST TO BE QUICKLY SHIFTED EAST AND MODEL THIS MORNING
INDICATING SUBSIDENCE ALONG WITH SOME DRIER AIR RETURNING BEHIND
THIS UPPER LEVEL TROUGH BY LATE DAY. GIVEN CLEARING KANSAS DURING
THE AFTERNOON WILL STAY CLOSE TO THE LATEST GUIDANCE WITH HIGHS
CLIMBING BACK INTO THE 30S WEDNESDAY AFTERNOON. A WARMING TREND
CAN THEN BE EXPECTED THROUGH THE REMAINDER OF THE WEEK BASED ON
IMPROVING AND PERSISTENT DOWNSLOPE FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 513 AM CST SUN JAN 11 2015
IFR CEILINGS WILL ATTEMPT TO SPREAD INTO THE DDC AREA EARLY THIS
MORNING AS SOUTH/SOUTHEASTERLY WINDS DRAW MORE HUMID AIR IN THE
LOWER LEVELS ACROSS SOUTH CENTRAL KANSAS. AT THIS TIME ONLY THE
NAM SPREADS THESE IFR CEILINGS FAR ENOUGH WEST TO IMPACT DDC AND
HYS BETWEEN 15 AND 18Z. AS OF 11Z...BASED ON THE LATEST SATELLITE
LOOP AND SURFACE OBSERVATIONS WILL FAVOR THE SLOWER HRRR AND
KEEPING THE MAIN STATUS JUST SOUTHEAST OF DDC. A COLD FRONT WILL
MOVE ACROSS SOUTHWEST KANSAS TODAY AND AS THIS COLD FRONT PASSES
THE SOUTH WINDS WILL SHIFT TO THE NORTH AND INCREASE TO 10 TO 15
KNOTS. IN ADDITION TO THE NORTH/NORTHEAST WINDS THE LOWER LEVELS
OF THE ATMOSPHERE WILL SATURATE FROM THE SURFACE AROUND 1500FT
AGL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 11 23 11 / 0 0 0 10
GCK 44 11 23 11 / 0 0 0 10
EHA 49 16 26 16 / 0 0 0 10
LBL 44 15 24 14 / 0 0 0 10
HYS 39 8 20 9 / 0 0 0 10
P28 39 16 26 13 / 0 10 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
515 AM CST SUN JAN 11 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST SUN JAN 11 2015
OTHER THAN POTENTIAL FOR FOG DEVELOPMENT LATER THIS MORNING, THE
SHORT TERM FORECAST IS ONE OF FAIRLY BENIGN WEATHER. SOMEWHAT
RELATIVE UNCERTAINTY EXISTS WITH RESPECT TO TEMPERATURES AT LEAST
THIS AFTERNOON AS WELL. THE WEAK COLD FRONT POISED TO MOVE INTO THE
AREA LATER TONIGHT WAS POSITIONED ACROSS NORTHWEST KANSAS INTO
EASTERN NEBRASKA. LIGHT SOUTHWEST WILL PERSIST AHEAD OF THIS SURFACE
FEATURE TODAY. ALREADY THIS MORNING, THE DEW POINT DEPRESSIONS HAVE
FALLEN TO ONE TO THREE DEGREES AT LOCATIONS LIKE SCOTT CITY, TO
SYRACUSE AND GARDEN CITY, WHERE THE NAM WAS MOST PRONOUNCED IN
DEVELOPING FOG. THE MODEL TREND WAS TO DEVELOP THIS SURFACE
RADIATION FOG BETWEEN AROUND 11 TO 14 Z BEFORE AN
INSOLATION/VERTICAL MIXING INDUCED DISSIPATION. TEMPERATURES FOR THIS
AFTERNOON WILL ALSO BE A CHALLENGE AS THE MID LEVEL CLOUDS NOW
INCREASING ACROSS SOUTH CENTRAL KANSAS WILL INHIBIT INSOLATION AND
RESULTANT SURFACE HEATING LATER IN THE MORNING. TEMPERATURES WILL BE
WARMEST IN THE WEST THIS AFTERNOON. THE COLD FRONT WILL PLUNGE
THROUGH WESTERN KANSAS AROUND 00 UTC AS A MID LEVEL WAVE SHIFTS INTO
EASTERN KANSAS THIS EVENING. THE MODELS AND MOS OUTPUT INDICATE A
HIGH LEVEL OF AGREEMENT ON LOWS OVERNIGHT IN THE LOW SINGLE DIGITS
CWA-WIDE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 350 AM CST SUN JAN 11 2015
MODELS THIS MORNING REMAIN IN GOOD AGREEMENT WITH AN UPPER LEVEL
TROUGH, LOCATED AROUND 50N 140W AT 00Z SUNDAY, MOVING ACROSS THE
NORTHWESTERN UNITED STATES ON MONDAY. BY 12Z TUESDAY THIS UPPER
LEVEL SYSTEM WILL BE LOCATED AROUND THE FOUR CORNERS REGION. AS
THIS NEXT SYSTEM MOVES INTO THE FOUR CORNERS REGION ON MONDAY A
SURFACE RIDGE AXIS WILL BE CROSSING CENTRAL KANSAS AND MID TO HIGH
LEVEL MOISTURE WILL BEGIN TO SPREAD ACROSS WESTERN KANSAS. BASED
ON THE INCREASING CLOUD COVER AND NORTHEAST/EASTERLY FLOW OF COLD
AIR IN THE LOWER LEVELS ADVECTING INTO WESTERN KANSAS THE PREVIOUS
FORECAST STILL LOOKS ON TRACK WITH HIGHS MAINLY IN THE LOW TO MID
20S.
MONDAY NIGHT AND TUESDAY THE SURFACE WINDS WILL GRADUALLY VEER TO
THE SOUTH/SOUTHEAST AS THE SURFACE HIGH SLIDES EAST TOWARDS THE
MISSISSIPPI VALLEY. AS THE SOUTH/SOUTHEASTERLY FLOW DEVELOPS THE
0-1KM AGL DEWPOINTS WILL BEGIN TO SLOWLY INCREASE ACROSS FAR
WESTERN/SOUTHWEST KANSAS AND WARM AIR ADVECTION WILL BEGIN TO
DEVELOP. 800MB TO 500MB MOISTURE IS ALSO FORECAST TO CONTINUE TO
INCREASE ACROSS THE CENTRAL HIGH PLAINS AS THE UPPER LEVEL TROUGH
MOVES EAST TOWARDS THE CENTRAL ROCKIES. AT THIS TIME PRECIPITATION
CHANCES THROUGH MID DAY ON TUESDAY APPEARS SMALL GIVEN THE LIMITED
LOW LEVEL MOISTURE AND LIFT, EVEN FROM THE MORE AGGRESSIVE NAM AND
ECMWF. BY TUESDAY AFTERNOON SOME LIGHT SNOW WILL BE POSSIBLE
ACROSS PORTIONS OF WESTERN GIVEN THE INCREASING MOISTURE AND LIFT
IN THE 900MB TO 800MB LEVEL FROM THE NAM AND ECMWF. THIS
PRECIPITATION WILL THEN SPREAD NORTH AND EAST THROUGH THE
OVERNIGHT HOURS AS 700MB FRONTOGENESIS IMPROVES AHEAD OF THE UPPER
LEVEL TROUGH/LOW WHICH WILL BE MOVING EAST ACROSS NEW MEXICO AND
COLORADO TUESDAY NIGHT. CONFIDENCE ON SNOWFALL AMOUNTS STILL
REMAIN LOW ACROSS WESTERN KANSAS THIS MORNING GIVEN THE CURRENT
DISCREPANCIES BETWEEN THE MODELS CONCERNING MOISTURE AND LIFT,
EVEN WITH THE ENHANCED LIFT FROM THE 700MB FRONTOGENISIS WHICH
WILL BE CROSSING WESTERN KANSAS DURING THE OVERNIGHT HOURS.
BY EARLY WEDNESDAY THE MOISTURE AND LIFT AHEAD OF THE UPPER LEVEL
TROUGH APPEARS TO BE CONFINED TO PORTIONS OF SOUTH CENTRAL KANSAS.
THIS IS FORECAST TO BE QUICKLY SHIFTED EAST AND MODEL THIS MORNING
INDICATING SUBSIDENCE ALONG WITH SOME DRIER AIR RETURNING BEHIND
THIS UPPER LEVEL TROUGH BY LATE DAY. GIVEN CLEARING KANSAS DURING
THE AFTERNOON WILL STAY CLOSE TO THE LATEST GUIDANCE WITH HIGHS
CLIMBING BACK INTO THE 30S WEDNESDAY AFTERNOON. A WARMING TREND
CAN THEN BE EXPECTED THROUGH THE REMAINDER OF THE WEEK BASED ON
IMPROVING AND PERSISTENT DOWNSLOPE FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 513 AM CST SUN JAN 11 2015
IFR CEILINGS WILL ATTEMPT TO SPREAD INTO THE DDC AREA EARLY THIS
MORNING AS SOUTH/SOUTHEASTERLY WINDS DRAW MORE HUMID AIR IN THE
LOWER LEVELS ACROSS SOUTH CENTRAL KANSAS. AT THIS TIME ONLY THE
NAM SPREADS THESE IFR CEILINGS FAR ENOUGH WEST TO IMPACT DDC AND
HYS BETWEEN 15 AND 18Z. AS OF 11Z...BASED ON THE LATEST SATELLITE
LOOP AND SURFACE OBSERVATIONS WILL FAVOR THE SLOWER HRRR AND
KEEPING THE MAIN STATUS JUST SOUTHEAST OF DDC. A COLD FRONT WILL
MOVE ACROSS SOUTHWEST KANSAS TODAY AND AS THIS COLD FRONT PASSES
THE SOUTH WINDS WILL SHIFT TO THE NORTH AND INCREASE TO 10 TO 15
KNOTS. IN ADDITION TO THE NORTH/NORTHEAST WINDS THE LOWER LEVELS
OF THE ATMOSPHERE WILL SATURATE FROM THE SURFACE AROUND 1500FT
AGL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 11 23 11 / 0 0 10 10
GCK 43 11 23 11 / 0 0 10 10
EHA 49 16 26 16 / 0 0 10 10
LBL 44 15 24 14 / 0 0 10 10
HYS 39 8 20 9 / 0 0 10 10
P28 39 16 26 13 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
400 AM MST SUN JAN 11 2015
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 400 AM MST SUN JAN 11 2015
TODAY-TONIGHT...LOOKS LIKE THE DAY WILL START OFF WITH SOME HIGH
CLOUDS GENERALLY NEAR THE KS/NE BORDER BUT AS THE DAY PROGRESSES MID
CLOUDS MOVE IN FROM THE NORTHWEST. LOW LEVELS OF THE ATMOSPHERE
REMAIN RATHER DRY SO NO PRECIPITATION EXPECTED. DURING THE OVERNIGHT
HOURS MODELS SUGGESTING A WEAK WEATHER DISTURBANCE PER 700-500MB
MOISTURE TO MOVE ALONG AND JUST SOUTH OF THE PALMER DIVIDE
BRINGING A SLIGHT CHANCE OF LIGHT SNOW TO PARTS OF FAR EASTERN
COLORADO...BEST CHANCE FOR CHEYENNE AND KIT CARSON COUNTIES. FOR
REMAINING AREAS GENERALLY ALONG/WEST OF THE CO/KS BORDER 850-700MB
MOISTURE SATURATES BUT MID LEVEL MOISTURE A BIT LACKING SO HAVE
KEPT SOME SMALL CHANCES FOR FLURRIES.
BIGGER CHALLENGE TODAY IS HIGH TEMPERATURES. MOST OF THE MODELS HAVE
BEEN WAY TOO COOL/COLD THE PAST SEVERAL DAYS EXCEPT FOR A FEW. HAVE
RELIED ON THOSE BETTER PERFORMING MODELS FOR THIS FORECAST AS TIMING
OF COLD FRONT AND ARRIVAL OF LEADING EDGE OF ARCTIC AIR WILL BE
CRITICAL. 18Z 850MB TEMPS SEVERAL DEGREES ABOVE 0F AND THROUGH 21Z
STILL ABOVE ZERO FOR ALL BUT THE NORTHERN EDGE OF YUMA COUNTY. BY
00Z THE COLD PUSH REACHES INTERSTATE 70. AFTER SEEING THE 9Z RUC AND
LATEST HRRR (WHICH DID RATHER WELL WITH SATURDAYS TEMPERATURES) HAVE
FINALIZED HIGHS IN THE MID/UPPER 30S ALONG/NORTH OF THE KS/NE BORDER
WITH 40S TO THE SOUTH. HAVE AROUND 50 IN THE TRIBUNE AREA. 1040MB
SFC HIGH REACHES THE AREA TONIGHT LOWS TONIGHT 5-10F ACROSS THE
NORTHEAST 1/2 OF THE AREA WITH 10-15F TO THE SOUTHWEST.
MONDAY-MONDAY NIGHT...1043MB SFC HIGH NOSING INTO THE AREA DURING
THE MORNING THEN WEAKENING JUST A BIT. SHOULD SEE SOME LINGERING
LIGHT SNOW ACROSS MOST OF FAR EASTERN COLORADO IN THE MORNING BEFORE
MID LEVEL MOISTURE MOVES AWAY LEAVING THE AREA UNDER PLENTY OF
CLOUDS. FOR THE OVERNIGHT HOURS WE ARE IN BETWEEN DEPARTING SYSTEM
AND APPROACHING UPPER TROUGH AND NEXT BATCH OF MOISTURE WITH SHORT
WAVE RIDGING OVER THE AREA. MID LEVEL MOISTURE LACKING FOR ANY
PRECIP SO JUST MOSTLY CLOUDY/CLOUDY CONDITIONS EXPECTED. HIGH
TEMPERATURES ONLY IN THE MID TEENS TO LOW 20S (NORTHEAST TO
SOUTHWEST ORIENTATION ACROSS THE AREA) WITH OVERNIGHT LOWS GENERALLY
5F-13F.
TUESDAY-TUESDAY NIGHT...AROUND SUNRISE BASE OF UPPER TROUGH EXPECTED
OVER SALT LAKE CITY AREA CLOSING OFF WHILE MOVING SOUTHEAST TOWARD
NORTHWEST NEW MEXICO/FOUR CORNERS AREA. DURING THE OVERNIGHT HOURS
WEAKEN THE LOW A BIT WHILE ALSO PUSHING IT EAST/SOUTHEAST.
FORECAST ISSUE FOR THE PERIOD IS TIMING AND PLACEMENT OF
PRECIPITATION CHANCES. MODELS IN GENERAL AGREE ON BRINGING
INCREASING MOISTURE TO THE AREA FROM THE WEST/SOUTHWEST DURING THE
DAY WITH A BIT OF DIFFERING SOLUTIONS AS TO WHETHER OR NOT SOME
DRIER AIR MOVES IN FROM THE NORTHWEST. NAM SAYS NO WHILE GFS/ECMWF
SAY YES. SO FOR NOW VERY LITTLE CHANGE MADE TO FORECAST. GFS/ECWMF
IN BETTER AGREEMENT BRINGING DRIER IN FROM THE NORTHWEST DURING THE
NIGHT WHICH IS SIMILAR TO LAST NIGHTS SOLUTIONS. SO FOR NOW...NO
CHANGES MADE.
TEMPERATURES WILL CONTINUE TO BE COLD WITH HIGH TEMPERATURES IN THE
LOW TO MID 20S AND LOWS GENERALLY 10-15F...COLDEST AROUND MCCOOK
WITH HIGHEST VALUES FROM FLAGLER TO LEOTI.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 211 AM MST SUN JAN 11 2015
FORECAST CHALLENGES ARE RESOLVING THE WARMING TEMPERATURES AND
PERSISTENT WEST TO EAST/WARM TO COOL GRADIENT ACROSS THE FORECAST
AREA.
THE UPPER TROUGH THAT MOVED THROUGH THE CENTRAL HIGH PLAINS REGION
LATE TUESDAY AND TUESDAY NIGHT MOVES OUT OF THE REGION WEDNESDAY.
NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY NIGHT AND THURSDAY AS THE
UPPER RIDGE MOVES OVER THE ROCKIES AND HIGH PLAINS. COLD AIR AT THE
SURFACE IS SWEPT OUT OF THE CENTRAL HIGH PLAINS AS THE HIGH PRESSURE
AREA MOVES EAST AND A LEE TROUGH DEEPENS NEAR THE EASTERN COLORADO
BORDER.
DIFFERENCES ARE SHOWING UP BETWEEN THE GFS AND ECMWF OVER THE
CENTRAL HIGH PLAINS REGION THURSDAY NIGHT AND FRIDAY. THE ECMWF IS
PRODUCING TWO SEPARATE WEAKER SHORT WAVE TROUGHS THAT MOVE ACROSS
THE FORECAST AREA WHILE THE GFS IS PRODUCING A STRONGER CLOSED LOW
CENTER THAT FITS INTO THE TIMING OF THE SECOND OPEN WAVE
IDENTIFIED BY THE ECMWF FRIDAY AFTERNOON AND EVENING. MAY END UP
JUST SEEING AN INCREASE IN HIGH CLOUDS ASSOCIATED WITH THE WAVE ON
FRIDAY...BUT EXTENDED BLEND MAY BE TOO DRY AS IT HAS VERY LITTLE
CLOUD COVER IN FORECAST BEYOND WEDNESDAY WITH OVERALL DRY
CONDITIONS AND TEMPERATURES WARMING THROUGH THE END OF THE WEEK
WITH RIDGING ALOFT EXPECTED ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 400 AM MST SUN JAN 11 2015
KGLD...VFR CONDITIONS THROUGH 22Z WITH WINDS VARIABLE AT 5KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH A GRADUAL
INCREASE IN CLOUDS STARTING MID TO LATE MORNING. AROUND 23Z
STRATUS STARTS TO APPROACH THE TERMINAL AS WINDS BECOME NORTHERLY
AROUND 10KTS. ITS EXPECTED THAT FROM 00Z THROUGH 11Z STRATUS WILL
COVER THE TERMINAL WITH VLIFR CIGS. SHORTLY AFTER 11Z STRATUS
CONCENTRATION SHIFTS TO THE WEST POSSIBLY ALLOWING VFR CONDITIONS
TO RETURN WITH NORTHEAST WINDS AROUND 10KTS. SOME SNOW FLURRIES
ARE POSSIBLE AT THE TAIL END OF THE PERIOD.
KMCK...VFR CONDITIONS THROUGH 20Z WITH WINDS VARIABLE AT 3KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH AN INCREASE IN
MID AND HIGH CLOUDS MID TO LATE MORNING. AROUND 21Z STRATUS
APPROACHES THE TERMINAL FROM THE NORTH WITH WINDS SHIFTING TO THE
NORTHEAST AROUND 5KTS. BY 23Z IF NOT AN HOUR OR POSSIBLY TWO
EARLIER VLIFR CIGS EXPECTED WITH NORTH WINDS AROUND 10KTS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z-07Z BEFORE
RETURNING TO VFR AS THE SATURATED LOW LEVEL AIRMASS MOVES
WEST/SOUTHWEST OF THE TERMINAL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...LOCKHART
AVIATION...99
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
653 AM EST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST SUN JAN 11 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF PERSISTING
OVER ERN NAMERICA. HOWEVER...HEIGHTS HAVE BEEN RISING SIGNIFICANTLY
OVER THE ERN CONUS (00Z RAOBS SHOW 12HR 500MB HEIGHT RISES OF
100-200M FROM THE UPPER MISSISSIPPI VALLEY TO THE E COAST)...
INDICATING A RELAXATION OF THE RECENT VERY COLD PATTERN. UPSTREAM...
A SHORTWAVE TROF IS DROPPING S INTO SASKATCHEWAN/MANITOBA. THIS WILL
BE THE MAIN FEATURE OF INTEREST IN THE SHORT TERM AS IT SWINGS SE
INTO THE UPPER GREAT LAKES LATE TONIGHT/MON MORNING. 850MB TEMPS ARE
CURRENTLY AROUND -18C PER LATEST RUC ANALYSIS...AND THIS IS
CONTINUING TO SUPPORT LES OVER LAKE SUPERIOR. A SFC TROF...ENHANCED
BY THE RELATIVELY WARM WATERS...EXTENDS ACROSS LAKE SUPERIOR EARLY
THIS MORNING. OVER WRN LAKE SUPERIOR...LAND BREEZE ENHANCED FLOW
AHEAD OF TROF IS FOCUSING LES MOSTLY OFFSHORE OF WRN UPPER MI...
EXCEPT OVER THE KEWEENAW. TO THE E...LES IS WELL OFFSHORE WITH HINTS
OF A CONVERGENT DOMINANT BAND ALONG TROF TO THE E OF STANNARD ROCK.
MODELS SHOW THE SFC TROF CURRENTLY OVER LAKE SUPERIOR WEAKENING AND
DRIFTING SE TODAY. OVER WRN LAKE SUPERIOR...NOT MUCH CHANGE IN WIND
DIRECTION IS INDICATED AS THIS OCCURS. OVER ERN LAKE SUPERIOR...LES
WILL DRIFT SLOWLY S AS WINDS BECOME MORE WNW. AS A RESULT...SCT TO
NMRS -SHSN WILL LINGER OVER NW UPPER MI TODAY...MAINLY THE
KEWEENAW...WHILE TO THE E...-SHSN SHOULD SETTLE/DEVELOP SE AND AT
LEAST BRUSH THE SHORE E OF MUNISING. -SHSN WON`T PUSH TOO FAR INLAND
SINCE THERE IS LITTLE N COMPONENT TO THE WIND. WITH INVERSION AT
3-4KFT...LES WILL BE ON THE LIGHT SIDE. DGZ DOES DOMINATE THE
CONVECTIVE LAYER THOUGH...AND THIS WILL LEAD TO HIGHER SNOW TO WATER
RATIOS. MIGHT SEE A COUPLE OF INCHES WHERE LES IS MOST PERSISTENT
TODAY. MEANWHILE...AHEAD OF THE APPROACHING SHORTWAVE TROF...MODELS
SHOW STRENGTHENING OF A JET STREAK FROM NRN MN TO NEW ENGLAND/SRN
QUEBEC TODAY. RIGHT ENTRANCE OF THIS JET MAY PROVIDE SUFFICIENT
FORCING FOR A STREAK OF -SN/FLURRIES TO DEVELOP AND SPREAD FROM MN
TO NRN WI/SRN UPPER MI LATE THIS AFTN/EVENING. OVER THE LAST DAY OR
SO...ALL MODEL GUIDANCE HAS TRENDED TOWARD SHOWING THIS STREAK OF
-SN. LOW-LEVEL DRY AIR WILL BE A HINDRANCE...BUT GIVEN MODEL
TRENDS...AT LEAST SCHC POPS ARE WARRANTED LATE AFTN/EVENING ACROSS
THE SRN FCST AREA.
TONIGHT...SHORTWAVE WILL SWING SE...PASSING ACROSS THE UPPER LAKES
LATE TONIGHT/MON MORNING. SINCE BULK OF THE DEEP LAYER FORCING
PASSES TO THE NE AND THERE IS AN ABSENCE OF ANY MOISTURE INFLOW IN
ADVANCE OF THIS DISTURBANCE...ACCOMPANYING PCPN SHOULD BE LIMITED TO
AREAS NEAR LAKE SUPERIOR. VEERING FLOW TO THE NW AND 850MB TEMPS
FALLING BACK TO -20 TO -24C BY 12Z MON IN THE WAKE OF ATTENDANT COLD
FROPA WILL BRING AN INCREASE IN LES TONIGHT INTO MON MORNING.
GFS/NAM FCST SOUNDINGS SHOW LIMITED IMPACT ON INVERSION...ONLY
RISING TO NEAR 5KFT...WHICH IS A LITTLE SURPRISING SINCE THE DEEP
LAYER FORCING PER QVECTORS IS NOT THAT WEAK. FORCING AND DEGREE OF
OVERWATER INSTABILITY WARRANTS CATEGORICAL POPS FOR AREAS FAVORED BY
NW WINDS TONIGHT. FOR NOW...EXPECT 1-3 INCHES OF SNOW BY DAYBREAK
MON. THE LONGER FETCH INTO NCNTRL UPPER MI AND DEEPER DGZ THERE
SUGGEST GREATER COVERAGE OF 2-3 INCH AMOUNTS WILL BE FROM MUNISING
EASTWARD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 438 AM EST SUN JAN 11 2015
DECENT AGREEMENT THAT LARGE TROUGH OVER EASTERN CANADA GRADUALLY
LOSES ITS INFLUENCE OVER THE GREAT LAKES BY NEXT WEEKEND. A COUPLE OF
LAST PUSHES OF ARCTIC AIR WILL GIVE UPPER GREAT LAKES GLANCING BLOWS
OF COLDER TEMPS...FIRST ON MONDAY...THEN AGAIN ON THURSDAY. BY NEXT
WEEKEND ZONAL FLOW IS IN FULL SWING AS STRONG JET STREAK PLOWING
ACROSS THE PACIFIC MASHES HEIGHTS DOWN OVER THE WESTERN CONUS. H85
TEMPS AS LOW AS -24C ON MONDAY MORNING WILL BE REPLACED WITH VALUES
RISING ABOVE ZERO ON FRIDAY. EXPECT TEMPS TO BE WELL INTO THE 20S AT
THE SFC BY THE TIME WE REACH LATE THIS WEEK.
INITIAL BATCH OF COLD AIR TIED TO SHORTWAVE DROPPING OVER THE AREA
TONIGHT RESULTS IN LAKE EFFECT SNOW SHOWERS KICKING UP IN NNW-N FLOW
INTO MONDAY MORNING. LIMITED DIRECT IMPACT FM THE SHORTWAVE TO
ENHANCE THE LES. INVERSIONS UP TO 5KFT AND GENERAL UNIDIRECTIONAL
FLOW WITHIN THE CLOUD LAYER WILL AID IN ORGANIZATION. SINCE MUCH OF
CLOUD LAYER IS WITHIN THE DGZ COULD SEE FEW INCHES OF FLUFFY
ACCUMULATION. A NEGATIVE FACTOR WILL BE BLYR WINDS STEADILY VEERING
FM NW TO NNE LATE TONIGHT INTO MONDAY MORNING WHICH WILL NOT ALLOW
THE BANDS TO AFFECT ANY ONE LOCATION FOR TOO LONG OF A DURATION.
TIMING WILL MATTER AS IF THE STRONGER LES DROPS ALONG LK SUPERIOR
EARLIER ON MONDAY...THEN THE MORNING COMMUTE WOULD BE IMPACTED. MAY
MENTION IN HWO...BUT OVERALL SEEMS LIKE MAY BE ABLE TO GET BY WITHOUT
HAVING A HEADLINE FOR THE LES. INVERSIONS LOWER FURTHER BY MONDAY
AFTN BELOW 5KFT AND LOW-LEVEL CONVERGENCE WEAKENS AS LARGE HIGH
PRESSURE RIDGE OVER 1040MB BUILDS FM THE NORTHERN PLAINS TOWARD THE
WESTERN GREAT LAKES...SO LES WILL CONTINUE TO TREND DOWNWARD IN
INTENSITY.
BY MONDAY NIGHT WHATEVER IS LEFT OF THE LES SHOULD BE SPUTTERING
ALONG AS MAINLY FLURRIES FOR THE SNOW BELTS EAST OF MARQUETTE AS
WINDS BACK NW. RIDGE/DRY AIR AND CONTINUAL BACKING WINDS WILL END
LES OVERNIGHT. CALM BUT COLD CONDITIONS INLAND WITH THE RIDGING
OVERHEAD. A BIT MORE OF A GRADIENT WSW WIND KEEPS TEMPS NOT AS COLD
OVER THE KEWEENAW AND NEAR LK SUPERIOR. INLAND THOUGH...PWATS LESS
THAN 0.10 INCH AND CALM CONDITIONS WILL RESULT IN PRIME RADIATIONAL
COOLING WITH TYPICAL COLD SPOTS POSSIBLY DROPPING TO READINGS LOWER
THAN 20 BLO. THANKFULLY NO WIND CHILL ISSUES AS IT SHOULD BE CALM
WHERE TEMPS ARE THAT LOW.
RIDGE STILL ENOUGH IN VCNTY TUESDAY TO LIMIT MIXING DEPTH AND THUS
KEEP MAX TEMPS IN THE LOW-MID TEENS. EXCEPTION WILL BE ALONG LK
SUPERIOR WEST THROUGH NCNTRL WHERE WSW FLOW PROVIDES SOME DOWNSLOPE
WARMING AND COULD BOOST TEMPS ABOVE 20 DEGREES. A RELATIVE HEAT
WAVE COMPARED TO THE CHILL THAT HAS BEEN AROUND THE LAST WEEK OR SO.
WSW WINDS MAY GET GUSTY OVER LK SUPERIOR AND KEWEENAW ON TUESDAY
NIGHT. MAY SEE WINDS OVER 30 MPH FOR PARTS OF THE KEWEENAW. WINDS MAY
STAY STRONG ENOUGH TO RESULT IN TEMPS NEAR LK SUPERIOR STAYING STEADY
OR ONLY SLIGHTLY FALLING. INLAND OVER WEST HALF...BLENDED BACK TOWARD
GOING FORECAST WITH MINS SLIPPING BLO ZERO AS IT WOULD NOT TAKE MUCH
DECOUPLING TO HAVE TEMPS FALL OFF IN INTERIOR SHELTERED AREAS. COULD
SEE DECENT RANGE IN MIN TEMPS OVR THE CWA THIS NIGHT.
WEAK LOW PRESSURE TROUGH...EXTENSION FM STRONGER LOW PRESSURE TIED
TO SHORTWAVE OVER NORTHERN ONTARIO...CROSSES LK SUPERIOR ON
WEDNESDAY. GIVEN WEST-SOUTHWEST WINDS...BEST CHANCE OF ANY LGT SNOW
WOULD BE ON THE KEWEENAW. ONCE THE TROUGH SLIDES FARTHER OVER THE
AREA ON WEDNESDAY NIGHT INTO THURSDAY...SHOWED CHANCES ALONG MUCH OF
THE NORTHERN CWA. MARGINAL FM A STRICT LES STANDPOINT WITH H85 TEMPS
ONLY AROUND -12C...BUT BOTH GFS AND ECMWF HINT AT ADDITIONAL FORCING
AND MOISTENING...SO COULD BE LAKE ENHANCED SNOW FOR AT LEAST A BRIEF
PERIOD. TROUGH THEN BOUNCES EAST ON FRIDAY AND MAY EVEN TAKE SHAPE
AS A WARM FRONT...AT LEAST ALOFT. DOES SEEM THAT GFS AND ECMWF HINT
THAT THERE WOULD BE SW-W WINDS FOR FRIDAY WITH H85 TEMPS WARMING
ABOVE 0C. GFS SOUNDINGS INDICATE SHALLOW MIXING HEIGHT WITH MOST OF
THE WARMING STAYING ALOFT. INCREASED TEMPS A BIT OVER CONSENSUS WITH
THE HINTS SHOWING UP AND HAVE MID 20S INLAND AND A SHOT AT CRACKING
30 DEGREES ALONG LK SUPERIOR WITH THE SW WINDS. RAN TEMPS UP TO 30
DEGREES FOR NOW...BUT BIAS CORRECTED ECMWF GUIDANCE DID HAVE EVEN
MID 30S. LIKELY WOULD NEED TO HAVE DECENT SUNSHINE/MIXING FOR THAT
TO HAPPEN...BUT FOR NOW INCHED HIGH TEMPS UP SOME. LAST TIME NWS
OFFICE IN NEGAUNEE TOWNSHIP SAW A HIGH TEMP OF 30 DEGREES WAS JUST
AFTER CHRISTMAS ON THE MORNING OF 27 DEC. TEMPS WENT IN A FREE FALL
AFTER THAT THOUGH AND HAVE ONLY BEEN ABOVE 20 DEGREES DURING THE
DAYTIME HOURS ON ONE DAY...3 JAN. A FEW DAYS WITH HIGHS IN THE 20S
WOULD BE QUITE WELCOME.
NO ADJUSTMENTS TO CONSENSUS FORECAST FOR NEXT WEEKEND AS ECMWF IS
TRYING TO SHOW A STRONGER/DIGGIER SHORTWAVE AND STRONGER COLD FRONT
PASSAGE...WHILE THE GFS TURNS MORE PROGRESSIVE AND KEEPS TROUGH TO
THE NORTH SO THUS ANOTHER WARMER DAY. GEM-NH ON ITS LAST PANEL AT 00Z
SAT 17 JAN LOOKS MORE LIKE THE GFS. USED A BLEND FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 652 AM EST SUN JAN 11 2015
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO AFFECT KCMX TODAY UNDER
WNW WINDS. THERE IS SOME UNCERTAINTY IN VIS/CIG IMPACTS...BUT SINCE
CONDITIONS FAVOR MOSTLY LIGHT PCPN...EXPECT MVFR CONDITIONS TO
PREVAIL WITH SOME BRIEF PERIODS OF IFR. COLD FRONT PASSING THIS
EVENING WILL LIKELY BRING A PERIOD OF IFR CONDITIONS TO KCMX...AND
POTENTIALLY LIFR. AS WINDS SHIFT TOWARD A NORTHERLY DIRECTION
OVERNIGHT WHICH IS TYPICALLY LESS FAVORABLE FOR POOR
CONDITIONS/PERSISTENT HEAVIER SNOW SHOWERS AT KCMX...EXPECT MVFR
CONDITIONS TO RETURN. AT KIWD/KSAW...VFR CONDITIONS WILL PREVAIL
INTO THE EVENING HRS AS LOW-LEVEL AIR MASS REMAINS RELATIVELY DRY.
AS WINDS SHIFT NW TONIGHT IN ASSOCIATION WITH COLD FROPA...LAKE
EFFECT SNOW SHOWERS WILL INCREASE AT KIWD...DROPPING CONDITIONS TO
IFR LATE. AT KSAW...EXPECT MVFR CONDITIONS TO DEVELOP OVERNIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST SUN JAN 11 2015
WINDS HAVE DIMINISHED BLO 25 KTS AND WILL STAY THAT WAY THROUGH MOST
OF TONIGHT EVEN AS LOW PRESSURE TROUGH WORKS ACROSS THE LAKE. STRONGER
COLD FRONT SWEEPS OVER LK SUPERIOR LATE TONIGHT AND EXPECT WINDS TO
SHIFT TO THE NORTH AND PEAK AROUND 30 KTS AROUND SUNRISE ON MONDAY...BEFORE
QUICKLY DIMINISHING TO LESS THAN 20 KTS ON MONDAY AFTN. HEAVY FREEZING
SPRAY WILL RETURN LATE TONIGHT BUT UNLIKE LAST WEEK...IT WILL NOT
LAST LONG...ENDING BY MONDAY EVENING AS HIGH PRESSURE DRIFTS ACROSS.
WINDS WILL INCREASE AGAIN LATE MONDAY NIGHT INTO TUESDAY OUT OF THE
SOUTHWEST. STRONGEST WINDS TO 30 KTS EXPECTED OVER WESTERN AND NORTH
CENTRAL LK SUPERIOR. COULD SEE GALE GUSTS TUESDAY AFTN INTO TUESDAY
EVENING BTWN TIP OF KEWEENAW AND ISLE ROYALE. HEAVY FREEZING SPRAY IS
NOT EXPECTED AS WILL BE HIGHER THAN SEEN RECENTLY. WINDS DIMINISH TO
25 KTS OR LESS BY WEDNESDAY AND SHOULD REMAIN AT SIMILAR SPEEDS
THROUGH LATE THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 4 PM EST MONDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TO 1 PM EST MONDAY FOR
LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 1 PM EST MONDAY FOR
LSZ242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
518 AM EST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST SUN JAN 11 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF PERSISTING
OVER ERN NAMERICA. HOWEVER...HEIGHTS HAVE BEEN RISING SIGNIFICANTLY
OVER THE ERN CONUS (00Z RAOBS SHOW 12HR 500MB HEIGHT RISES OF
100-200M FROM THE UPPER MISSISSIPPI VALLEY TO THE E COAST)...
INDICATING A RELAXATION OF THE RECENT VERY COLD PATTERN. UPSTREAM...
A SHORTWAVE TROF IS DROPPING S INTO SASKATCHEWAN/MANITOBA. THIS WILL
BE THE MAIN FEATURE OF INTEREST IN THE SHORT TERM AS IT SWINGS SE
INTO THE UPPER GREAT LAKES LATE TONIGHT/MON MORNING. 850MB TEMPS ARE
CURRENTLY AROUND -18C PER LATEST RUC ANALYSIS...AND THIS IS
CONTINUING TO SUPPORT LES OVER LAKE SUPERIOR. A SFC TROF...ENHANCED
BY THE RELATIVELY WARM WATERS...EXTENDS ACROSS LAKE SUPERIOR EARLY
THIS MORNING. OVER WRN LAKE SUPERIOR...LAND BREEZE ENHANCED FLOW
AHEAD OF TROF IS FOCUSING LES MOSTLY OFFSHORE OF WRN UPPER MI...
EXCEPT OVER THE KEWEENAW. TO THE E...LES IS WELL OFFSHORE WITH HINTS
OF A CONVERGENT DOMINANT BAND ALONG TROF TO THE E OF STANNARD ROCK.
MODELS SHOW THE SFC TROF CURRENTLY OVER LAKE SUPERIOR WEAKENING AND
DRIFTING SE TODAY. OVER WRN LAKE SUPERIOR...NOT MUCH CHANGE IN WIND
DIRECTION IS INDICATED AS THIS OCCURS. OVER ERN LAKE SUPERIOR...LES
WILL DRIFT SLOWLY S AS WINDS BECOME MORE WNW. AS A RESULT...SCT TO
NMRS -SHSN WILL LINGER OVER NW UPPER MI TODAY...MAINLY THE
KEWEENAW...WHILE TO THE E...-SHSN SHOULD SETTLE/DEVELOP SE AND AT
LEAST BRUSH THE SHORE E OF MUNISING. -SHSN WON`T PUSH TOO FAR INLAND
SINCE THERE IS LITTLE N COMPONENT TO THE WIND. WITH INVERSION AT
3-4KFT...LES WILL BE ON THE LIGHT SIDE. DGZ DOES DOMINATE THE
CONVECTIVE LAYER THOUGH...AND THIS WILL LEAD TO HIGHER SNOW TO WATER
RATIOS. MIGHT SEE A COUPLE OF INCHES WHERE LES IS MOST PERSISTENT
TODAY. MEANWHILE...AHEAD OF THE APPROACHING SHORTWAVE TROF...MODELS
SHOW STRENGTHENING OF A JET STREAK FROM NRN MN TO NEW ENGLAND/SRN
QUEBEC TODAY. RIGHT ENTRANCE OF THIS JET MAY PROVIDE SUFFICIENT
FORCING FOR A STREAK OF -SN/FLURRIES TO DEVELOP AND SPREAD FROM MN
TO NRN WI/SRN UPPER MI LATE THIS AFTN/EVENING. OVER THE LAST DAY OR
SO...ALL MODEL GUIDANCE HAS TRENDED TOWARD SHOWING THIS STREAK OF
-SN. LOW-LEVEL DRY AIR WILL BE A HINDRANCE...BUT GIVEN MODEL
TRENDS...AT LEAST SCHC POPS ARE WARRANTED LATE AFTN/EVENING ACROSS
THE SRN FCST AREA.
TONIGHT...SHORTWAVE WILL SWING SE...PASSING ACROSS THE UPPER LAKES
LATE TONIGHT/MON MORNING. SINCE BULK OF THE DEEP LAYER FORCING
PASSES TO THE NE AND THERE IS AN ABSENCE OF ANY MOISTURE INFLOW IN
ADVANCE OF THIS DISTURBANCE...ACCOMPANYING PCPN SHOULD BE LIMITED TO
AREAS NEAR LAKE SUPERIOR. VEERING FLOW TO THE NW AND 850MB TEMPS
FALLING BACK TO -20 TO -24C BY 12Z MON IN THE WAKE OF ATTENDANT COLD
FROPA WILL BRING AN INCREASE IN LES TONIGHT INTO MON MORNING.
GFS/NAM FCST SOUNDINGS SHOW LIMITED IMPACT ON INVERSION...ONLY
RISING TO NEAR 5KFT...WHICH IS A LITTLE SURPRISING SINCE THE DEEP
LAYER FORCING PER QVECTORS IS NOT THAT WEAK. FORCING AND DEGREE OF
OVERWATER INSTABILITY WARRANTS CATEGORICAL POPS FOR AREAS FAVORED BY
NW WINDS TONIGHT. FOR NOW...EXPECT 1-3 INCHES OF SNOW BY DAYBREAK
MON. THE LONGER FETCH INTO NCNTRL UPPER MI AND DEEPER DGZ THERE
SUGGEST GREATER COVERAGE OF 2-3 INCH AMOUNTS WILL BE FROM MUNISING
EASTWARD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 438 AM EST SUN JAN 11 2015
DECENT AGREEMENT THAT LARGE TROUGH OVER EASTERN CANADA GRADUALLY
LOSES ITS INFLUENCE OVER THE GREAT LAKES BY NEXT WEEKEND. A COUPLE OF
LAST PUSHES OF ARCTIC AIR WILL GIVE UPPER GREAT LAKES GLANCING BLOWS
OF COLDER TEMPS...FIRST ON MONDAY...THEN AGAIN ON THURSDAY. BY NEXT
WEEKEND ZONAL FLOW IS IN FULL SWING AS STRONG JET STREAK PLOWING
ACROSS THE PACIFIC MASHES HEIGHTS DOWN OVER THE WESTERN CONUS. H85
TEMPS AS LOW AS -24C ON MONDAY MORNING WILL BE REPLACED WITH VALUES
RISING ABOVE ZERO ON FRIDAY. EXPECT TEMPS TO BE WELL INTO THE 20S AT
THE SFC BY THE TIME WE REACH LATE THIS WEEK.
INITIAL BATCH OF COLD AIR TIED TO SHORTWAVE DROPPING OVER THE AREA
TONIGHT RESULTS IN LAKE EFFECT SNOW SHOWERS KICKING UP IN NNW-N FLOW
INTO MONDAY MORNING. LIMITED DIRECT IMPACT FM THE SHORTWAVE TO
ENHANCE THE LES. INVERSIONS UP TO 5KFT AND GENERAL UNIDIRECTIONAL
FLOW WITHIN THE CLOUD LAYER WILL AID IN ORGANIZATION. SINCE MUCH OF
CLOUD LAYER IS WITHIN THE DGZ COULD SEE FEW INCHES OF FLUFFY
ACCUMULATION. A NEGATIVE FACTOR WILL BE BLYR WINDS STEADILY VEERING
FM NW TO NNE LATE TONIGHT INTO MONDAY MORNING WHICH WILL NOT ALLOW
THE BANDS TO AFFECT ANY ONE LOCATION FOR TOO LONG OF A DURATION.
TIMING WILL MATTER AS IF THE STRONGER LES DROPS ALONG LK SUPERIOR
EARLIER ON MONDAY...THEN THE MORNING COMMUTE WOULD BE IMPACTED. MAY
MENTION IN HWO...BUT OVERALL SEEMS LIKE MAY BE ABLE TO GET BY WITHOUT
HAVING A HEADLINE FOR THE LES. INVERSIONS LOWER FURTHER BY MONDAY
AFTN BELOW 5KFT AND LOW-LEVEL CONVERGENCE WEAKENS AS LARGE HIGH
PRESSURE RIDGE OVER 1040MB BUILDS FM THE NORTHERN PLAINS TOWARD THE
WESTERN GREAT LAKES...SO LES WILL CONTINUE TO TREND DOWNWARD IN
INTENSITY.
BY MONDAY NIGHT WHATEVER IS LEFT OF THE LES SHOULD BE SPUTTERING
ALONG AS MAINLY FLURRIES FOR THE SNOW BELTS EAST OF MARQUETTE AS
WINDS BACK NW. RIDGE/DRY AIR AND CONTINUAL BACKING WINDS WILL END
LES OVERNIGHT. CALM BUT COLD CONDITIONS INLAND WITH THE RIDGING
OVERHEAD. A BIT MORE OF A GRADIENT WSW WIND KEEPS TEMPS NOT AS COLD
OVER THE KEWEENAW AND NEAR LK SUPERIOR. INLAND THOUGH...PWATS LESS
THAN 0.10 INCH AND CALM CONDITIONS WILL RESULT IN PRIME RADIATIONAL
COOLING WITH TYPICAL COLD SPOTS POSSIBLY DROPPING TO READINGS LOWER
THAN 20 BLO. THANKFULLY NO WIND CHILL ISSUES AS IT SHOULD BE CALM
WHERE TEMPS ARE THAT LOW.
RIDGE STILL ENOUGH IN VCNTY TUESDAY TO LIMIT MIXING DEPTH AND THUS
KEEP MAX TEMPS IN THE LOW-MID TEENS. EXCEPTION WILL BE ALONG LK
SUPERIOR WEST THROUGH NCNTRL WHERE WSW FLOW PROVIDES SOME DOWNSLOPE
WARMING AND COULD BOOST TEMPS ABOVE 20 DEGREES. A RELATIVE HEAT
WAVE COMPARED TO THE CHILL THAT HAS BEEN AROUND THE LAST WEEK OR SO.
WSW WINDS MAY GET GUSTY OVER LK SUPERIOR AND KEWEENAW ON TUESDAY
NIGHT. MAY SEE WINDS OVER 30 MPH FOR PARTS OF THE KEWEENAW. WINDS MAY
STAY STRONG ENOUGH TO RESULT IN TEMPS NEAR LK SUPERIOR STAYING STEADY
OR ONLY SLIGHTLY FALLING. INLAND OVER WEST HALF...BLENDED BACK TOWARD
GOING FORECAST WITH MINS SLIPPING BLO ZERO AS IT WOULD NOT TAKE MUCH
DECOUPLING TO HAVE TEMPS FALL OFF IN INTERIOR SHELTERED AREAS. COULD
SEE DECENT RANGE IN MIN TEMPS OVR THE CWA THIS NIGHT.
WEAK LOW PRESSURE TROUGH...EXTENSION FM STRONGER LOW PRESSURE TIED
TO SHORTWAVE OVER NORTHERN ONTARIO...CROSSES LK SUPERIOR ON
WEDNESDAY. GIVEN WEST-SOUTHWEST WINDS...BEST CHANCE OF ANY LGT SNOW
WOULD BE ON THE KEWEENAW. ONCE THE TROUGH SLIDES FARTHER OVER THE
AREA ON WEDNESDAY NIGHT INTO THURSDAY...SHOWED CHANCES ALONG MUCH OF
THE NORTHERN CWA. MARGINAL FM A STRICT LES STANDPOINT WITH H85 TEMPS
ONLY AROUND -12C...BUT BOTH GFS AND ECMWF HINT AT ADDITIONAL FORCING
AND MOISTENING...SO COULD BE LAKE ENHANCED SNOW FOR AT LEAST A BRIEF
PERIOD. TROUGH THEN BOUNCES EAST ON FRIDAY AND MAY EVEN TAKE SHAPE
AS A WARM FRONT...AT LEAST ALOFT. DOES SEEM THAT GFS AND ECMWF HINT
THAT THERE WOULD BE SW-W WINDS FOR FRIDAY WITH H85 TEMPS WARMING
ABOVE 0C. GFS SOUNDINGS INDICATE SHALLOW MIXING HEIGHT WITH MOST OF
THE WARMING STAYING ALOFT. INCREASED TEMPS A BIT OVER CONSENSUS WITH
THE HINTS SHOWING UP AND HAVE MID 20S INLAND AND A SHOT AT CRACKING
30 DEGREES ALONG LK SUPERIOR WITH THE SW WINDS. RAN TEMPS UP TO 30
DEGREES FOR NOW...BUT BIAS CORRECTED ECMWF GUIDANCE DID HAVE EVEN
MID 30S. LIKELY WOULD NEED TO HAVE DECENT SUNSHINE/MIXING FOR THAT
TO HAPPEN...BUT FOR NOW INCHED HIGH TEMPS UP SOME. LAST TIME NWS
OFFICE IN NEGAUNEE TOWNSHIP SAW A HIGH TEMP OF 30 DEGREES WAS JUST
AFTER CHRISTMAS ON THE MORNING OF 27 DEC. TEMPS WENT IN A FREE FALL
AFTER THAT THOUGH AND HAVE ONLY BEEN ABOVE 20 DEGREES DURING THE
DAYTIME HOURS ON ONE DAY...3 JAN. A FEW DAYS WITH HIGHS IN THE 20S
WOULD BE QUITE WELCOME.
NO ADJUSTMENTS TO CONSENSUS FORECAST FOR NEXT WEEKEND AS ECMWF IS
TRYING TO SHOW A STRONGER/DIGGIER SHORTWAVE AND STRONGER COLD FRONT
PASSAGE...WHILE THE GFS TURNS MORE PROGRESSIVE AND KEEPS TROUGH TO
THE NORTH SO THUS ANOTHER WARMER DAY. GEM-NH ON ITS LAST PANEL AT 00Z
SAT 17 JAN LOOKS MORE LIKE THE GFS. USED A BLEND FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1246 AM EST SUN JAN 11 2015
ALTHOUGH WRLY FLOW LES OVER THE KEWEENAW HAS SHIFTED NORTH OF
CMX...EXPECT THAT THE AREA OF FAVORABLE LOW LEVEL CONV WILL DROP
BACK TO THE SOUTH OVERNIGHT...BRINGING LIGHT LES BACK INTO CMX. WITH
THE GENERALLY LIGHT WINDS...THERE IS MORE UNCERTAINTY ON WHERE THE
LES BANDS WILL DEVELOP AND HOW LONG THEY WILL PERSIST AT THE
TERMINAL. HOWEVER...THERE IS SUFFICIENT INSTABILITY TO SUPPORT LES
INTO THE IFR RANGE TODAY AS WEST WINDS INCREASE. WINDS WILL VEER TO
THE NW BY LATE EVENING BEHIND A COLD FRONT AND BECOME MORE GUSTY.
FOR KIWD/KSAW...EXPECT VFR CONDITIONS TO PREVAIL FOR THE TAF PERIOD.
ONLY OCCASIONAL MID/HIGH CLOUDS ARE EXPECTED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST SUN JAN 11 2015
WINDS HAVE DIMINISHED BLO 25 KTS AND WILL STAY THAT WAY THROUGH MOST
OF TONIGHT EVEN AS LOW PRESSURE TROUGH WORKS ACROSS THE LAKE. STRONGER
COLD FRONT SWEEPS OVER LK SUPERIOR LATE TONIGHT AND EXPECT WINDS TO
SHIFT TO THE NORTH AND PEAK AROUND 30 KTS AROUND SUNRISE ON MONDAY...BEFORE
QUICKLY DIMINISHING TO LESS THAN 20 KTS ON MONDAY AFTN. HEAVY FREEZING
SPRAY WILL RETURN LATE TONIGHT BUT UNLIKE LAST WEEK...IT WILL NOT
LAST LONG...ENDING BY MONDAY EVENING AS HIGH PRESSURE DRIFTS ACROSS.
WINDS WILL INCREASE AGAIN LATE MONDAY NIGHT INTO TUESDAY OUT OF THE
SOUTHWEST. STRONGEST WINDS TO 30 KTS EXPECTED OVER WESTERN AND NORTH
CENTRAL LK SUPERIOR. COULD SEE GALE GUSTS TUESDAY AFTN INTO TUESDAY
EVENING BTWN TIP OF KEWEENAW AND ISLE ROYALE. HEAVY FREEZING SPRAY IS
NOT EXPECTED AS WILL BE HIGHER THAN SEEN RECENTLY. WINDS DIMINISH TO
25 KTS OR LESS BY WEDNESDAY AND SHOULD REMAIN AT SIMILAR SPEEDS
THROUGH LATE THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 4 PM EST MONDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TO 1 PM EST MONDAY FOR
LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 1 PM EST MONDAY FOR
LSZ242-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS HASTINGS NE
520 AM CST SUN JAN 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 253 AM CST SUN JAN 11 2015
THE FOCUS DURING THE SHORT TERM PERIODS WILL AGAIN BE CENTERED
AROUND CLOUDS AND TEMPERATURES. THE PATTERN ALOFT FEATURED
WESTERLY FLOW ACROSS OUR REGION WITH EMBEDDED WAVES IN THE FLOW.
ONE SUCH WAVE WAS TRANSLATING ACROSS KS...WHICH WILL HAVE LITTLE
CONSEQUENCE FOR OUR AREA. FARTHER NORTH ENERGY MOVING SOUTH FM
CANADA WAS MOVING SOUTH INTO THE NORTHERN PLAINS AND THIS WILL
SEND A REINFORCING COLD FRONT ACROSS THE PLAINS LATE THIS AFTN AND
TONIGHT.
CURRENT CONDITIONS AS OF 08Z PLACED A COOL FRONTAL BOUNDARY JUST
SOUTH OF THE PLATTE RIVER. TEMPERATURES BEHIND THE FRONT AVERAGED IN
THE SINGLE DIGITS AND TEENS WHILE AHEAD OF THE BOUNDARY READINGS
AVERAGED IN THE MIDDLE 20S. SO FAR FOG HAS YET TO FORM AND IF TRENDS
CONTINUE WILL REMOVE MENTION FOR THE EARLY MORNING HOURS.
WITH NO REAL PUSH OF THE FRONT TODAY...THE BOUNDARY IS ONLY EXPECTED
TO GRADUALLY SAG SOUTH INTO OUR SOUTHERN ZONES LATE THIS AFTN OR
EARLY EVENING. AHEAD OF THE FRONT TEMPS COULD EASILY BE QUITE
MILD IN THE 40S ACROSS MUCH OF KS...SIMILAR TO RAP DEPICTION BUT
THIS WILL ALSO BE DEPENDENT UPON CLOUD COVER. THE NAM IS ALSO ROBUST
WITH LLVL MOISTURE AND LOW CLOUDS LIFTING NORTH AHEAD OF THE
APPROACHING SHORTWAVE AND SURGES MOISTURE NORTH OF THE FRONT. THE
GFS KEEPS THE BRUNT OF THE CLOUDS SOUTH OF THE BOUNDARY. THE NAM
IS STILL SUFFERING FROM OVERZEALOUS SNOWPACK INITIALIZATION AND
LLVL MOISTURE FIELDS LIKELY DUE TO POTENTIAL SNOW MELT AND HAD TO
SHY AWAY FROM IT FOR THIS FORECAST. FOR THE FORECAST TODAY...HAVE
WENT WITH VARYING CLOUD COVER THRU THE FIRST PART OF THE AFTN WITH
TEMPS SIMILAR TO RAP WITH READINGS RANGING FROM THE UPPER 20S IN
OUR NORTHERN CWA (NORTH OF FRONT) TO TEMPS IN THE 40S ACROSS MUCH
OF NORTH CENTRAL KS (SOUTH OF BOUNDARY). CLOUD COVER WILL INCREASE
AND TEMPS COOL N/S WITH ARRIVAL OF SECONDARY COLD FRONT LATER THIS
AFTN AND TONIGHT.
CLOUD COVER WITH FRONT/WAVE WILL BE AT MID/HIGH LEVELS SO NOT
LOOKING FOR PCPN WITH THE SECONDARY COLD FRONT THIS EVENING/TONIGHT.
COLDER CONDITIONS WILL SETTLE IN DURING THE NIGHT AS A 1045 MB
SURFACE HIGH BUILDS SOUTH FM THE DAKOTAS. THE AIRMASS CHANGE IS A
DROP OF NEARLY 10C AT H85 FROM THIS MORNING TO MONDAY MORNING.
OVERNIGHT LOWS PRIMARILY IN THE SINGLE DIGITS COMBINED WITH A STEADY
NORTH WIND WILL PRODUCE WIND CHILLS BELOW ZERO BUT VALUES ARE NOT
LOOKING QUITE COLD ENOUGH FOR AN HWO MENTION ATTM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 253 AM CST SUN JAN 11 2015
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM LIE WITH
TEMPERATURES AND EARLY WEEK PRECIPITATION CHANCES.
MONDAY STILL ON TRACK TO BE THE COLDEST DAY OF THE FORECAST
PERIOD...WITH MODELS IN GOOD AGREEMENT SHOWING THE CWA BEING ON THE
SOUTHERN END OF AN UPPER LEVEL TROUGH AXIS EXTENDING BACK UP INTO
THE HUDSON BAY AREA. THIS TROUGH CONTINUES TO SWING THROUGH/EAST OF
THE CWA DURING THE DAYTIME HOURS MONDAY...WITH ZONAL TO SLIGHT NWRLY
FLOW BUILDING IN BEHIND. EVEN WITH THIS TROUGH SWINGING
THROUGH...MODELS NOT SHOWING AN ABUNDANCE OF MOISTURE AND CONTINUE
TO KEEP CONDITIONS DRY. THIS SYSTEM BRINGS A REINFORCING SHOT OF
NRLY WINDS AND COLDER AIR...SPEEDS ARE ONLY TOPPING OUT AROUND 10 TO
15 MPH IN THE MORNING...BUT WILL DIMINISH WITH TIME AS SFC HIGH
PRESSURE SETTLES FURTHER SOUTH. THE CENTER OF THE SFC HIGH REMAINS
OFF TO THE N/NE OF THE CWA...ENDING UP OVER FAR NERN NEB AT
00Z...THEN SHIFTS OVER TO THE CENTRAL PORTIONS OF THE IA/MN BORDER
BY TUESDAY MORNING...WHICH WILL BRING A GRADUAL TRANSITION IN WINDS
TO THE EAST THAN MORE SOUTHERLY BY 12Z TUESDAY. DID NOT MAKE NOTABLE
CHANGES TO INHERITED HIGHS FOR MONDAY...WHICH RANGE FROM THE LOWER
TEENS IN THE FAR NORTH TO LOWER 20S ACROSS NC KS. OVERNIGHT LOWS
MONDAY NIGHT/TUESDAY MORNING LOOK TO BOTTOM OUT IN THE SINGLE DIGITS
BELOW ZERO IN THE NORTHEAST TO NEAR 10 DEGREES IN THE FAR SW.
TUESDAY/TUESDAY NIGHT...MAIN STORY LIES WITH AN UPPER LEVEL
DISTURBANCE WHICH BY SUNRISE TUESDAY HAS DUG SOUTH INTO THE CENTRAL
ROCKIES/4 CORNERS REGION...WITH ZONAL FLOW IN PLACE ACROSS OUR AREA.
THROUGH THE DAYTIME HOURS...MODELS IN DECENT AGREEMENT SHOWING A
CLOSED CIRCULATION DEVELOPING OVER THE 4 CORNERS REGION...AND
TREKKING MAINLY EAST INTO THE TUESDAY NIGHT PERIOD...BUT ALSO
FILLING WITH TIME. THE 00Z ECMWF/GFS/GEM ARE ALL IN PRETTY GOOD
AGREEMENT SHOWING THE BRUNT OF THIS SYSTEM SLIDING TO THE SOUTH OF
THE CWA...BARELY GETTING CLIPPED BY THE NRN EDGE OF
PRECIPITATION...IF AT ALL. DISCOUNTED THE 00Z NAM...WHICH WAS
NOTABLY FURTHER NORTH AND DEEPER WITH THE SYSTEM...AND SHOWED SOME
LOCATIONS GETTING UPWARDS OF 4 INCHES OF SNOW. THE 06Z RUN HAS COME
MORE IN LINE WITH THE ECMWF/GFS/GEM. CONTINUED TO KEEP SOME 30-40
POPS CONFINED TO THE FAR S/SWRN PORTIONS OF THE CWA...WITH SOME 20
POPS BUFFERING THAT AREA TO THE NORTH. AT THIS POINT...IF SNOW DOES
MAKE IT FAR ENOUGH NORTH TO AFFECT OUR CWA...NOT EXPECTING MUCH IN
THE WAY OF ACCUMULATION. EXPECTING A BUMP UP IN TEMPS...WITH HIGHS
CURRENTLY FORECAST TO REACH THE LOWER 20S.
THROUGH THE REMAINDER OF THE LONG TERM PERIOD...WEDNESDAY THROUGH
SATURDAY...THE FORECAST CONTINUES TO BE A DRY ONE...WITH MODELS IN
DECENT AGREEMENT SHOWING NORTHWESTERLY FLOW DEVELOPING FOR WED/THURS
THANKS TO AT LEAST BRIEF RIDGING OVER THE WRN CONUS...BEFORE
BECOMING MORE ZONAL INTO FRI/SAT WITH AN APPROACHING DISTURBANCE
FROM THE NW. EXPECTING MODERATING TEMPERATURES ALOFT TO WORK THEIR
WAY IN FROM THE WEST...AND ALONG WITH THE POTENTIAL FOR MORE
DOWNSLOPING WRLY WINDS ESP THURS/FRI...TEMPS CLIMB A BIT EACH
DAY...AND ARE FORECAST BACK IN THE LOW/MID 40S CWA-WIDE FOR FRIDAY.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 518 AM CST SUN JAN 11 2015
VFR CONDITIONS ARE FORECAST THRU THE TAF PERIOD. CLOUD COVER IS
EXPECTED TO BE VARIABLE TODAY...BUT INCREASE/THICKEN BY LATE AFTN
INTO TONIGHT WITH THE PASSAGE OF A SECONDARY COLD FRONTAL
BOUNDARY. WINDS WILL REMAIN FROM A NORTHERLY DIRECTION AND WILL
INCREASE NEAR 15KTS BEHIND THE FRONT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...ADP
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1020 AM EST SUN JAN 11 2015
.SYNOPSIS...
SOUTHERLY FLOW WILL DRAW MILDER AIR INTO THE OHIO VALLEY TODAY...
ALONG WITH INCREASING MOISTURE. THIS WILL SET THE STAGE FOR A THE
DEVELOPMENT OF A MIX OF SNOW...SLEET...AND FREEZING RAIN ACROSS
THE AREA THIS AFTERNOON INTO MONDAY. DRY CONDITIONS WILL RETURN
MONDAY NIGHT AS HIGH PRESSURE BUILDS OVER THE GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
ADDITIONAL UNCERTAINTY NOW WITH WARMER MODEL SOLUTIONS...CREATING
THE GREATER LIGHT ICE ACCUMULATION THREAT A LITTLE FURTHER NORTH
FROM CONNERSVILLE/RICHMOND THROUGH DAYTON AND NORTHEAST TO
DELAWARE OHIO. THIS AREA WILL ALSO MIX WITH SOME SLEET AND SNOW.
WHILE COBB SOLUTION FROM HRRR AND RAP DO HAVE THE CVG/ILN TEMPERATURE
PROFILE WITH PRECIPITATION TYPE AS MOSTLY RAIN...THE BIG CAVEAT
HERE IS ROAD SURFACE TEMPERATURES STILL 25 TO 29 DEGREES. DESPITE
AIR TEMPS RISING ABOVE FREEZING IN THIS AREA...THE CURRENT
THINKING IS THAT CLOUDS TODAY WILL NOT ALLOW ROAD SURFACE
TEMPERATURES TO RISE ABOVE FREEZING SO SEEMINGLY WET SURFACES WILL
BECOME GLAZED WITH ICE.
TEMPERATURES TODAY EVEN ARE TRICKY...WITH HIGH RESOLUTION MODELS
INDICATING BIG WARMUP AT PORTSMOUTH TO ABOVE 40 FOR HIGHS...BUT VERY
SLOW WARMUP SO FAR SO KEEPING WITH THE UPPER 30S. NEAR 30 FOR MOST
OTHER LOCATIONS...AND MID 30S NEAR/SOUTH OF OHIO RIVER.
PREVIOUS DISCUSSION FOLLOWS...
MID LEVEL FLOW BACKS SW AHEAD OF SRN SHORTWAVE TROF WHICH
EJECTS NE INTO OHIO VALLEY TONIGHT. THIS S/W PHASES WITH THE NRN
STREAM AND DAMPENS OUT AHEAD OF NRN STREAM TROF WHICH DROPS SE
THRU THE GREAT LAKES TONIGHT INTO MONDAY. 45 KT 8H JET DEVELOPS
THIS AFTN AHEAD OF THE AFOREMENTIONED S/W. THIS WILL LEAD TO
FAVORABLE ISENTROPIC LIFT AND LOW LEVEL CONVERGENCE. NATIONAL
RADAR MOSAIC ALREADY SHOWS LEADING EDGE OF PRECIP SPREADING NORTH
FROM THE SRN PLAINS INTO THE LOWER MS VLY INTO FAR WESTERN TN/WRN
KY. SYNOPTIC MODELS HOLD OFF PRECIP UNTIL LATE THIS AFTN INTO THE
WESTERN HALF OF THE FA. HOWEVER...MESOSCALE MODELS SHOW AN AXIS
OF PRECIP THAT PIVOTS N PRIOR TO THE MAIN AREA FILLING IN. AIRMASS
IS VERY DRY...SO THIS INITIAL SHOT OF PRECIP WILL LIKELY AT LEAST
PARTIALLY EVAPORATE AND LEAD TO EVAPORATIVE COOLING. GIVEN HOW FAR
NORTH THE PRECIP ALREADY IS HAVE ONLY SLOWED ONSET VERY SLIGHTLY
TO ACCOUNT FOR THIS EVAPORATION...WITH POPS LKLY INTO THE WEST BY
EVENING.
MODEL SOLNS HAVE TRENDED WARMER AND CURRENT SFC TEMPERATURES ARE
RUNNING WARMER THAN GUIDANCE. NAM SOLN IS STRONGER WITH THE LLJ
AND THEREFORE IS WARMER AND HAS MORE QPF. WHILE THE GFS/ECMWF SOLNS
HAVE LESS QPF BUT ARE COOLER. HAVE USED A BLENDED APPROACH FOR SFC
TEMPERATURES AND TOP DOWN GFS SOLN TO PRODUCE PRECIPITATION TYPE.
THIS YIELDS SNOW MIXING WITH AND CHANGING TO FREEZING RAIN ACRS
ALL BUT THE SE WHERE RAIN WILL PREVAIL. THE FAR NW WILL LKLY REMAIN
MAINLY SNOW.
AGREE WITH LATEST PC PROBABILITY GRAPHICS WITH MAINLY SNOW ACRS
FAR NRN PORTIONS OF WEST CENTRAL OHIO WHERE 1 TO 3 INCHES STORM
TOTAL LKLY AND LOCALLY UP TO 4 INCHES POSSIBLE. THE BEST AREA FOR
ICE ACCUMULATION LOOKS TO OCCUR IN A BAND FROM NEAR RICHMOND TO
NORTH OF DAYTON TO NORTH OF COLUMBUS. (THE NORTHERN I-70
CORRIDOR). STORM TOTAL ICE TOTALS HERE LOOK TO BE ONE TO TWO
TENTHS OF AN INCH.
OVERNIGHT TEMPERATURES WILL NOT DROP OFF TOO MUCH WITH LOWS FROM
THE UPPER 20S NW TO THE MID 30S SE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
NRN STREAM TROF TO DROPS SE THRU THE GREAT LAKES MONDAY. ASSOCIATED
SFC FRONT TO SWEEP SE THRU ILN/S FA MONDAY MORNING. PRECIPITATION
WILL DECREASE DURING THE DAY AND TAPER OFF MONDAY EVENING. EXPECT
PRECIP TO CHANGE TO SNOW IN LOW LEVEL CAA BUT WITH DEEP MOISTURE SHIFTING
EAST DAYTIME SNOW WILL BE AN INCH OR LESS WITH THE HIGHEST TOTALS
OVER WEST CENTRAL OHIO. EXPECT NON-DIURNAL TEMPERATURES MONDAY
WITH EARLY HIGHS RANGING FROM NEAR 30 NW TO THE UPPER 30S SE.
IN LOW LEVEL CAA PATTERN READINGS TO BE 5 TO 10 DEGREES BELOW
NORMAL MONDAY NIGHT WITH LOWS FROM THE SINGLE DIGITS ACROSS NW
PORTIONS OF THE FA WHERE THERE WILL BE MORE SNOW ON THE GROUND TO
THE LOW 20S ACROSS THE FAR SOUTHERN PORTIONS OF THE FA.
SFC HIGH PRESSURE TO BUILD ACRS THE GREAT LAKES TUESDAY...OFFERING
DRY CONDITIONS AND TEMPERATURES 10 TO 13 DEGREES BELOW NORMAL.
HIGHS ARE EXPECTED TO RANGE FROM THE MID/UPR TEENS NW TO THE UPPER
20S SE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
CAA UNDER NE FLOW LINGERS INTO WED AND THEN MOSTLY QUIET EXTENDED
PERIOD AS OVERALL FLOW BECOMES MORE AMPLIFIED AHEAD OF THE WEST
COAST RIDGE. A WEAK SHORT WAVE PASSES THROUGH THE GREAT LAKES AT
THE SAME TIME THE SOUTHERN STREAM RAMPS UP A MORE PRONOUNCED
THROUGH TO PULL JUST OFF THE EAST COAST. AT THIS TIME...FORECAST
AREA APPEARS TO BE BETWEEN BOTH OF THESE SYSTEMS...WITH MORE
LIKELY AFFECTS TO COME FROM THE GREAT LAKES SHORT WAVE...SO HAVE
KEPT SMALL CHANCES OF SNOW SHOWERS ACROSS THE NORTH ON THURSDAY
NIGHT BUT OTHERWISE CONTINUED DRY. BOTH OPERATIONAL AND PARALLEL
GFS AND ECMWF HAVE THESE SYSTEMS IN RELATIVELY CLOSE AGREEMENT AND
THEN RIDGING AGAIN FOR THE WEEKEND.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BE MOVING EAST TODAY. TROUGH OF LOW PRESSURE
CARRYING MOISTURE OVER A COLD SURFACE LAYER WILL PRODUCE A WINTRY
MIX OF PRECIPITATION STARTING AROUND 22Z. NORTHERN TAF SITES DAY
CMH AND LCK SHOULD SEE MAINLY SN AND PL TRANSITIONING TO
FZRAPL THEN BACK TO SNOW...WHILE FARTHER SOUTH AT CVG LUK AND
ILN...PRECIP SHOULD CHANGE TO RAIN. MVFR CONDITIONS ARE EXPECTED
WITH THE PRECIP...DROPPING TO IFR AS THE BOUNDARY LAYER BECOMES
SATURATED TOWARD THE END OF THE FORECAST. WINDS ARE FORECAST TO
STAY OUT OF THE SOUTH UNDER 10 KNOTS...SHIFTING TO SOUTHWEST LATE.
AS THE SYSTEM MOVES EAST ON MONDAY...WIND WILL SHIFT TO NORTHWEST
AT CVG IN VCSH.
OUTLOOK...MVFR CEILINGS MAY LINGER INTO MONDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 4 PM EST MONDAY FOR OHZ026-034-
035-042>046-051>056-060>065-070>072-077.
FREEZING RAIN ADVISORY UNTIL 10 AM EST MONDAY FOR OHZ073-074-
078>080.
KY...FREEZING RAIN ADVISORY UNTIL 10 AM EST MONDAY FOR KYZ089>093.
IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST MONDAY FOR INZ050-058-
059-066-073-074.
FREEZING RAIN ADVISORY UNTIL 10 AM EST MONDAY FOR INZ075-080.
&&
$$
SYNOPSIS...AR
NEAR TERM...JDR
SHORT TERM...AR
LONG TERM...JDR
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
953 AM EST SUN JAN 11 2015
.SYNOPSIS...
MOISTURE/CLOUDS INCREASES TODAY...BUT NOT QUITE AS COLD IN AFTERNOON.
COLD FRONT SAGS SOUTH MONDAY. WEAK WAVE OF LOW PRESSURE SOUTH
POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
BASED ON LATEST MODELS AND SATELLITE TRENDS...WILL INCREASE CLOUD
COVER FOR THIS AFTERNOON.
AM A BIT CONCERNED WITH THE MODEL TRENDS OF GETTING WARMER FOR THIS
AFTERNOON AND TONIGHT IN SOUTHEAST OHIO. MET/MAV AND LAV GUIDANCE
ARE MUCH WARMER THAN FORECAST...BUT THE HRRR STILL SHOWS WET BULBING
CAUSING ISSUES. WILL HOLD TIGHT FOR THE MORNING UPDATE...BUT WILL
HAVE TO TAKE A GOOD HARD LOOK FOR THE AFTERNOON PACKAGE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY/...
TEMPERATURES ALREADY MAINLY ABOVE FREEZING TO START THE
PERIOD...EXCEPT FOR VERY NW CWA IN PERRY AND MORGAN COUNTY. SO
LINGER WINTER WEATHER ADVISORY THERE UNTIL 9AM FOR FREEZING
RAIN...POSSIBLY MIXED WITH SOME SLEET/SNOW. HAVE HIGH POPS AT THE
START OF THE PERIOD...AS COLD FRONT BEGINS MOVING THROUGH. THAT
FRONT WILL CROSS CWA MONDAY WITH MAINLY RAIN. AS THE COLD AIR WORKS
IN LATER MONDAY AND MONDAY NIGHT...EXPECT A TRANSITION FROM RAIN TO
SLEET TO SNOW. MOISTURE ALREADY BECOMING FAIRLY LIMITED BY THE TIME
COLD ENOUGH AIR WORKS IN FOR SNOW...SO ONLY HAVE LIGHT ACCUMULATIONS
AND MAINLY IN THE NORTHERN MOUNTAINOUS COUNTIES.
A WAVE RIDES UP THE FRONT TUESDAY...SO HANG ONTO POPS ACROSS THE
EAST INTO TUESDAY NIGHT...THEN GRADUALLY DECREASE. DO HAVE HIGHER
POPS FOR THIS THAN PREVIOUS FORECAST...BUT STILL ONLY GETTING UP TO
AROUND A 40 PERCENT CHANCE AS THE MAIN ACTIVITY LOOKS TO STAY SE OF
CWA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
COLDER AIR SWEEPS IN FOR A SEASONABLY COOL EXTENDED. AFTER THE
SYSTEM MONDAY/EARLY TUESDAY...APPEARS A MAINLY DRY EXTENDED IS IN
THE CARDS. THE MODELS CONTINUE E WITH SYSTEM MIDWEEK. DID LEAVE SOME
SMALL POPS ACROSS E HALF OF CWA FOR MIDWEEK AS THIS SYSTEM MAY TREND
A BIT W WITH TIME.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT 10Z...STILL LIKE OUR 06Z TRENDS OF BRINGING THE CLOUD DECK AT 7
TO 8 THSD FT NE INTO CWA FASTER. HAVE THE POTENTIAL OF SOME SLEET OR
FLAKES IN SE OHIO THIS AFTERNOON...BUT POPS ONLY IN CHANCE RANGE.
AS POPS INCREASE THIS EVENING...MILDER AIR ALOFT. HAVE SOME
FREEZING RAIN POSSIBLE AS FAR SOUTH AS JUST NORTH OF HTS IN
SOUTHEAST OHIO AND INTO THE PKB VCNTY...WITH HIGHER RISK OF FREEZING
RAIN IN INTERIOR SECTIONS OF SE OHIO.
CONDITIONS DETERIORATING WITH WIDESPREAD MVFR CEILING AND VSBY
DEVELOPING 03Z TO 06Z. MOSTLY RAIN HTS-CRW-BKW ON SOUTH...WITH RAIN
AND POCKETS OF FREEZING RAIN ALONG THE UNI-PKB-CKB-EKN CORRIDOR.
CEILINGS BECOMING 2 TO 3 THSD FT AND VSBY 3 TO 5 MILES 03Z TO 06Z.
BY 12Z MONDAY...FREEZING RAIN LESS WIDESPREAD WITH MOSTLY LIGHT RAIN.
AS COLUMN CONTINUES TO SATURATE...CONFIDENCE LOWERED TO MEDIUM...NOT
SURE HOW LOW THE CEILINGS WILL GO BETWEEN 06Z AND 12Z ESPECIALLY IN
SE OHIO AND ALSO OVER THE MOUNTAIN COUNTIES OF WV.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIO: SOME RENEGADE INITIAL PCPN MAY REACH THE GROUND
IN THE OHIO VALLEY IN THE FORM OF SOME SLEET PELLETS OR FLAKES 18Z
TODAY TO 00Z MONDAY...DROPPING VSBY BRIEFLY LOWER.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z MONDAY...
IFR POSSIBLE MONDAY...AND MOUNTAINS AND SOUTHERN COUNTIES MONDAY
NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR WVZ009>011.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM EST
MONDAY FOR OHZ066-067.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR OHZ075-076-083>085.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...RPY
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
323 AM MST SUN JAN 11 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 320 AM MST SUN JAN 11 2015
CURRENT IR SATELLITE LOOP AND SURFACE OBS ACROSS THE REGION SHOW
YET ANOTHER REINFORCING SHOT OF COLD ARCTIC AIR ACROSS
MONTANA...PUSHING SOUTHWARD EARLY THIS MORNING. THE LEADING EDGE
OF THE FRONT APPEARS TO HAVE JUST PUSHED INTO NORTHERN
WYOMING...WITH WINDS SHIFTING INTO THE NORTH AT GILLETTE AND
SHERIDAN AND INCREASING BAROMETRIC PRESSURE. THANKFULLY...MODELS
SHOW THE BULK OF THE COLDEST AIR STAYING EAST OF THE REGION AS
SOUTHEAST WYOMING AND WESTERN NEBRASKA AS THE AREA GETS BRUSHED BY
THE ARCTIC DOME OVER THE DAKOTAS BY THIS TIME TOMORROW MORNING.
HOWEVER...WE EXPECT MORE SNOWFALL IN THIS EVENT COMPARED TO THE
PREVIOUS ARCTIC FRONTAL PASSAGES IN THE LAST WEEK AS FRONTOGENESIS
COMBINES WITH UPSLOPE FLOW AND MID TO UPPER LEVEL DYNAMICS FROM A
SERIES OF UPPER LEVEL DISTURBANCES MOVING ACROSS THE GREAT BASIN
REGION AND INTO THE CENTRAL ROCKY MOUNTAINS THROUGH LATE MONDAY
NIGHT.
THE ARCTIC FRONT AND ASSOCIATED COLDER AIRMASS WILL BEGIN TO PUSH
INTO THE REGION LATE THIS MORNING...AND THEN ACROSS THE REST OF
THE HIGH PLAINS INTO COLORADO THROUGH THIS AFTERNOON. HIGH
TEMPERATURES WILL OCCUR SOMETIME THIS MORNING BEFORE TEMPERATURES
LOWER INTO THE TEENS AND 20S ACROSS THE HIGH PLAINS LATE THIS
AFTERNOON. THE FRONT WILL THEN STALL NEAR OR JUST WEST OF THE
LARAMIE RANGE...CREATING A NATURAL CONVERGENCE BOUNDARY WITH EAST
TO SOUTHEAST WINDS ACROSS THE HIGH PLAINS AND WEST TO SOUTHWEST
WINDS WEST OF THE FRONT. IN ADDITION...SOME WARM AIR ADVECTION
ALOFT AROUND 700MB IS EXPECTED AHEAD OF EACH UPPER LEVEL
DISTURBANCE AS THEY MOVE TOWARDS THE FORECAST AREA. THIS WILL
CREATE LIFT AND WILL ACT LIKE A WARM FRONTAL BOUNDARY WITH
RELATIVELY WARM AND MOIST AIR OVERRUNNING COLD AIR NEAR THE
SURFACE. EXPECT A HIGH POP/LOW QPF EVENT BEGINNING LATE TODAY
THROUGH TONIGHT. SNOWFALL WILL REMAIN NEAR THE MOUNTAINS THROUGH
MOST OF TODAY...BUT WHEN THE ARCTIC FRONT MOVES SOUTH AND WEST
ACROSS THE AREA...SNOWFALL WILL THEN DEVELOP FURTHER EAST ACROSS
EXTREME SOUTHEAST WYOMING AND WESTERN NEBRASKA. MAINLY EXPECT
LIGHT SNOW INTENSITY...WITH PERHAPS SOME BANDS OF MODERATE SNOW
ALONG THE LARAMIE RANGE AND IN THE MOUNTAINS. 3 TO 6 INCHES OF
SNOW APPEARS TO BE A GOOD BET FOR THE MOUNTAINS THROUGH
TONIGHT...WITH 1 TO 3 INCHES FOR THE HIGH VALLEYS AND HIGH PLAINS.
PRETTY SURE A FEW LOCATIONS OUTSIDE THE MOUNTAINS WILL RECEIVE 4
OR 5 INCHES...BUT THESE WILL BE TOO ISOLATED AND DIFFICULT TO PIN
DOWN FOR A WINTER WEATHER ADVISORY AT THIS TIME. WITH WINDS
SHIFTING INTO THE SOUTH BY EARLY MONDAY MORNING...THE POTENTIAL
FOR DENSE FOG IS HIGH OVER THE CHEYENNE RIDGE AND SOUTHERN LARAMIE
RANGE DUE TO USPLOPE FLOW FROM THE OPPOSITE DIRECTION. THERE IS A
SMALL CHANCE AT SOME FREEZING DRIZZLE...BUT CURRENT MODEL
SOUNDINGS DO NOT SUPPORT A WIDESPREAD EVENT FOR MORE THAN AN HOUR
OR TWO.
EXPECT A BRIEF BREAK ON MONDAY AS THE LOW AND UPPER LEVELS DRY OUT
A BIT...BUT MAY STILL HAVE SOME LINGERING FOG WITH SOUTHERLY WINDS
THROUGH THE DAY ACROSS THE CHEYENNE RIDGE. MODELS THEN SHOW THE
THIRD UPPER LEVEL DISTURBANCE PUSHING ONSHORE AND DEVELOPING A
MORE POTENT UPPER LEVEL TROUGH ACROSS THE EASTERN GREAT BASIN
REGION. THIS SYSTEM WILL BRING A HIGHER CHANCE OF MODERATE TO
HEAVY SNOW TO THE WASATCH AND WEST OF THE CONTINENTAL DIVIDE.
MODELS HAVE CONTINUED TRENDING THIS SYSTEM SOUTH OF THE FORECAST
AREA...AS IT DIGS SOUTHEAST INTO THE FOUR CORNERS REGION AND
CONTINUES MOVING SOUTHEAST OR EAST. HOWEVER...WILL HAVE TO MONITOR
THE EVOLUTION OF THIS SYSTEM AS IT PUSHES ONSHORE SINCE THE 00Z
AND 06Z NAM SHOW THE TROUGH BECOMING A CLOSED LOW AS IT DRIFTS
EAST OVER COLORADO. THIS SOLUTION WOULD TYPICALLY RESULT IN MORE
SNOWFALL ACROSS SOUTHEAST WYOMING. KEPT POP FOR THE LOWER
ELEVATIONS OF SOUTHEAST WYOMING BETWEEN 15 TO 25 PERCENT FOR
NOW...WITH VALUES BELOW 10 PERCENT EAST OF I25. TEMPERATURES WILL
BE BELOW NORMAL FOR BOTH MONDAY AND TUESDAY...WITH HIGHS IN THE
20S TO LOW 30S...WARMEST WEST OF THE LARAMIE RANGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 219 AM MST SUN JAN 11 2015
00Z MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT WITH A MEAN RIDGE
WEST OF THE ROCKIES AND A TROUGH FROM THE GREAT PLAINS EASTWARD
MIDWEEK. THE RIDGE TRANSLATES EAST AND DEAMPLIFIES AS SHORTWAVE
ENERGY MOVES FROM THE PACIFIC NORTHWEST ACROSS ID/MT INTO WY/NE
THURSDAY THROUGH FRIDAY. NOT EXPECTING ANY PRECIPITATION AS MOISTURE
WILL BE LIMITED. WILL SEE AN INCREASE IN WESTERLY WINDS FRIDAY WITH
GUSTS OF 30 TO 40 KT POSSIBLE OVER THE NORTHERN LARAMIE RANGE. HIGH
TEMPERATURES WILL MODERATE FROM THE 20S AND 30S WEDNESDAY TO THE
30S AND 40S THURSDAY AND FRIDAY. THE MILD TEMPERATURES WILL LIKELY
PERSIST INTO NEXT WEEKEND AS A MORE ZONAL PATTERN ALOFT DEVELOPS
WITH BREEZY TO WINDY WESTERLY WINDS CONTINUING. THERE ARE INDICATIONS
THAT PACIFIC MOISTURE WILL SPREAD EAST INTO SOUTH CENTRAL WY SUNDAY
WITH LIGHT SNOW POSSIBLE ACROSS SOUTHERN CARBON COUNTY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 219 AM MST SUN JAN 11 2015
LATEST HRRR MODEL DATA DEPICTS VFR CONDITIONS PREVAILING EAST OF
THE LARAMIE RANGE THROUGH MIDDAY FOLLOWED BY DETERIORATING CIGS
AND VSBYS THIS AFTERNOON AS A COLD FRONT PUSHES SOUTH ACROSS THE
FORECAST AREA. WEST OF THE LARAMIE RANGE...MVFR TO IFR CONDITIONS
WILL DEVELOP IN LOW CIGS AND LIGHT SNOW. THE MOUNTAINS WILL BE
OBSCURED THROUGH THE PERIOD. WINDS WILL SHIFT FROM SOUTHWESTERLY
TO NORTHERLY WITH FROPA. SPEEDS WILL AVERAGE LESS THAN 15 KT.
&&
.FIRE WEATHER...
ISSUED AT 159 AM MST SUN JAN 11 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEK WITH COOL
TEMPERATURES...UNSETTLED CONDITIONS AT TIMES...AND HIGH HUMIDITIES
CONTINUING OVER THE AREA. A WARMING TREND IS EXPECTED BY LATE THIS
WEEK...BUT DAYTIME HUMIDITIES WILL REMAIN OVER 40 PERCENT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...TJT
LONG TERM...MJ
AVIATION...MJ
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
931 AM MST SUN JAN 11 2015
.SYNOPSIS...
UNSETTLED WEATHER WILL CONTINUE TO BE THE STORY THROUGH THE EARLY
PART OF THIS WEEK...AS A SERIES OF FAST MOVING TROUGHS CONTINUE TO
MOVE THROUGH THE DESERT SOUTHWEST. SHOWERS WILL ONCE AGAIN BE
POSSIBLE THIS AFTERNOON INTO MONDAY MORNING...FOLLOWED BY A
SLIGHT CHANCE AGAIN EARLY TUESDAY. HIGH PRESSURE WILL RETURN TO THE
AREA BY MID WEEK WITH DRY WEATHER AND SLOWLY INCREASING TEMPERATURES
EXPECTED FROM WEDNESDAY INTO NEXT WEEKEND.
&&
.DISCUSSION...
LATEST SATELLITE IMAGERY SHOWS A MODESTLY IMPRESSIVE SHORTWAVE
TROUGH OVER SOUTHERN CALIFORNIA WITH THE PV ANOMALY CENTERED ALONG
THE SOUTHERN CALIFORNIA COAST. UPPER LEVEL ANALYSIS SHOWS A RATHER
COMPACT...BUT STRONG JET STREAK ALONG THE BASE OF THE UPPER TROUGH.
THIS WILL PROVIDE SOME NECESSARY LIFT FOR SHOWER DEVELOPMENT TODAY
AND TONIGHT. IR IMAGERY SHOWS AN EXTENSIVE AREA OF STRATO-CU
STREAMING NORTHEASTWARD OVER BAJA AND SOUTHEAST CALIFORNIA IN AN
AREA OF 0.75 TO 1.00 INCH PRECIPITABLE WATER. ISOLATED SHOWERS HAVE
BEEN FAIRLY PERSISTENT ACROSS PORTIONS OF SOUTHEAST CALIFORNIA SO
FAR THIS MORNING AND EXPECTING THESE TO INCREASE IN COVERAGE
SOMEWHAT BY LATE AFTERNOON AS THE PV ANOMALY SWINGS THROUGH. AM ALSO
ANTICIPATING SOME SHOWER DEVELOPMENT OVER THE GULF OF CALIFORNIA OR
NORTHWEST SONORA MEXICO THIS AFTERNOON WHICH WILL MOVE INTO YUMA
COUNTY BY LATE THIS AFTERNOON AND THROUGH THE REST OF SOUTH-CENTRAL
ARIZONA THIS EVENING. HAVE INCREASED POPS IN THESE AREAS INTO THE
CHANCE CATEGORY AND KEEPING THE LIKELY WORDING FROM PHOENIX EASTWARD
FOR LATE THIS EVENING INTO THE OVERNIGHT. RAINFALL AMOUNTS ARE NOT
EXPECTED TO BE MUCH WITH MOST LOCATIONS SEEING UP TO A TENTH OF AN
INCH...BUT SOME LOCALIZED SPOTS SHOULD RECEIVE A QUARTER OF AN
INCH.
&&
.PREVIOUS DISCUSSION...
THE LOW TO THE WEST OF LOS ANGELES HAS BEEN WELL ADVERTISED FOR THE
PAST SEVERAL DAYS...HOWEVER IT WOULD SUBJECTIVELY APPEAR THAT IT IS
A BIT MORE INTENSE THAN THE 00Z MODELS INDICATED. 00Z NAM AND GFS
AND TO SOME EXTENT THE EUROPEAN DON`T INDICATE ANY PRECIPITATION
ACROSS SOUTHERN CALIFORNIA THIS MORNING AND THIS IS OBVIOUSLY
INCORRECT. HRRR AND HI-RES MODELS ARE ALSO STRUGGLING A BIT AT THE
MOMENT BUT THE PARALLEL GFS /13KM/ SEEMS TO HAVE A DECENT HANDLE ON
THE SITUATION AND APPEARS TO HAVE INITIALIZED THE BEST OF ANY
AVAILABLE MODEL. GFS13 SUGGESTS THE LOW WILL MOVE ONSHORE LATER THIS
MORNING WITH PRECIPITATION DEVELOPING OVER ARIZONA LATER THIS
AFTERNOON/EVENING AS IT TAPS INTO SOMEWHAT HIGHER MID/LOWER
TROPOSPHERIC MOISTURE. MODEL QPF OVER THE PAST FEW DAYS HAS NEVER
BEEN MUCH MORE THAN A FEW HUNDREDTHS TO A TENTH OF AN INCH ACROSS
THE DESERTS /CLOSER TO A QUARTER OF AN INCH EAST OF PHOENIX/ AND
THIS STILL HOLDS TRUE WITH TODAY`S 00Z MODELS /INCLUDING THE GFS13/.
LOOKS LIKE A HIGH POP...LOW QPF EVENT. BUMPED UP POPS QUITE A BIT
THIS EVENING AND OVERNIGHT FOR ARIZONA ALTHOUGH SOUTHEAST CALIFORNIA
MAY END UP MISSING OUT ON THE MAJORITY OF THE RAINFALL. TIMING IS
LARGELY UNCHANGED FROM WHAT I INHERITED /06Z-18Z MONDAY IS THE
PRIMARY TIME FOR RAIN CHANCES/.
SHOWERS WILL TAPER OFF QUICKLY MONDAY NIGHT YET MOISTURE WILL REMAIN
SOMEWHAT ELEVATED BEHIND THE DEPARTING TROUGH. ON ITS HEELS WILL BE
THE SYSTEM PRESENTLY WEST OF WASHINGTON/OREGON AS IT IS FORECAST TO
DIVE SOUTHWARD THROUGH THE GREAT BASIN AND INTO ARIZONA TUESDAY
MORNING. AS THERE WILL BE SOME MOISTURE IN PLACE AND THE COLD CORE
OF THE LOW WILL PASS SOMEWHAT CLOSE TO THE FORECAST AREA...I WILL
RETAIN AT LEAST A 20-30 POP EAST OF PHOENIX FOR TUESDAY/TUESDAY
AFTERNOON PER SREF AND NAEFS GUIDANCE. HOWEVER THE OVER-LAND
TRAJECTORY OF THIS TROUGH SHOULD MITIGATE WIDESPREAD PRECIPITATION
ACROSS THE REST OF THE AREA.
LOOKING AHEAD TO WEDNESDAY AND BEYOND...RIDGING WILL RETURN TO THE
AREA BUT NOT NEARLY TO THE EXTENT AS WAS SEEN A FEW DAYS AGO. THIS
SHOULD RESULT IN GRADUALLY INCREASING TEMPERATURES AND LITTLE TO NO
CHANCE OF PRECIPITATION ACROSS THE AREA. HIGHS WILL EVENTUALLY CREEP
BACK INTO THE MID 70S BY LATE WEEK/NEXT WEEKEND.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT INCREASING CLOUD COVER AND CIGS LOWERING TO AROUND 7KFT AT
TIMES AFTER 20Z THIS AFTERNOON...AND CONTINUING OVERNIGHT BEFORE
BECOMING SCATTERED AOA 9KFT LATE MONDAY MORNING. ORGANIZED SHOWERS
SHOULD HOLD OFF UNTIL LATER THIS EVENING/AFTER 04Z MONDAY. SURFACE
WINDS WILL REMAIN VERY LIGHT WITH PROLONGED PERIODS OF VARIABLE
DIRECTION THROUGH AT LEAST 12 MONDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
TUESDAY WILL SEE THE FINAL IN A SERIES OF TROUGHS MOVE THROUGH THE
AREA. LOOKS LIKE THE BEST CHANCE OF PRECIPITATION WILL BE IN THE
MOUNTAINS EAST OF PHOENIX. SHOWERS SHOULD TAPER OFF QUICKLY TUESDAY
NIGHT WITH DRY WEATHER FORECAST WEDNESDAY INTO THE WEEKEND. THERE
COULD ALSO BE SOME LOCALIZED BREEZINESS WITH THE TUESDAY SYSTEM
ESPECIALLY DOWN THE COLORADO RIVER AND ACROSS THE RIDGETOPS EAST OF
PHOENIX. NOTHING HIGH ENOUGH TO WARRANT ANY FIRE WEATHER HEADLINES
THOUGH. AS FOR MOISTURE...HUMIDITIES WILL DROP A BIT FROM MID WEEK
ONWARD YET AFTERNOON READINGS WILL ONLY DROP INTO THE 20-30 PERCENT
RANGE WITH GOOD OVERNIGHT RECOVERIES EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...LEINS
AVIATION...MEYERS
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1121 AM MST SUN JAN 11 2015
UPDATED THE FORECAST BASED ON THE LATEST HIGH RESOLUTION MODEL
DATA FOR THIS AFTERNOON AND TONIGHT. RADAR AND SATELLITE INDICATE
THE FRONTAL BOUNDARY HAS PUSHED THROUGH THE PALMER DIVIDE WITH
INCREASED CLOUDS AND LIGHT RADAR RETURNS. NOT SEEING ANY REPORTS
FROM OBSERVATIONS OF PRECIPITATION REACHING THE GROUND YET AS DEW
POINT DEPRESSIONS ARE STILL HIGH. EXPECT THE FRONT TO CONTINUE
SOUTH THIS AFTERNOON...WITH CLOUD COVER FILLING IN BY THIS EVENING
ALONG ALL OF THE I-25 CORRIDOR. MODELS HAVE SNOW BY 6 PM OVER EL
PASO COUNTY...AND QUICKLY SATURATING SOUTH TO PUEBLO THROUGH THE
EVENING. BASED ON THE LATEST DATA...INCREASED SNOWFALL TOTALS FOR
THIS EVENING WITH 1 TO 3 INCHES OF EL PASO COUNTY AND AROUND HALF
AN INCH IN PUEBLO. THERE IS THE POSSIBILITY THAT SNOW COULD BE
HEAVIER AT TIMES...ESPECIALLY FOR A SHORT PERIOD FROM 8 PM THROUGH
AROUND MIDNIGHT...AND LOCALLY HIGHER AMOUNTS ARE POSSIBLE. MOZLEY
UPDATE ISSUED AT 903 AM MST SUN JAN 11 2015
UPDATED TO EXPIRE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY.
OBSERVATIONS INDICATE A FEW AREAS OF FOG STILL PERSIST AND WILL
CONTINUE TO PRODUCE REDUCED VISIBILITIES THROUGH NOON. MOZLEY
UPDATE ISSUED AT 724 AM MST SUN JAN 11 2015
MADE ADJUSTMENTS TO PRIMARILY NEAR-TERM GRIDS AS WELL AS SOME OF
THE SHORT-TERM GRIDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1029 AM MST SUN JAN 11 2015
KALS...LOW STRATUS WILL PERSIST ACROSS THE SAN LUIS VALLEY THROUGH
MONDAY MORNING. EXPECT FOG TO REDEVELOP THIS EVENING WITH IFR TO
LIFR CONDITIONS DUE TO LOWERED CIGS AND VIS. SNOW SHOWERS OVER THE
MOUNTAINS COULD MOVE INTO THE VALLEY AND MAY BRIEFLY IMPACT THE
TERMINAL TONIGHT.
KCOS...A COLD FRONT IS CURRENTLY DROPPING SOUTH OVER THE PALMER
DIVIDE WITH LOW STRATUS AND SNOW EXPECTED TO DEVELOP OVER THE
TERMINAL THROUGH THIS AFTERNOON. MODEL GUIDANCE SUGGESTS SNOW WILL
BE HEAVIEST BETWEEN 03-08Z TONIGHT WITH A COUPLE OF INCHES OF SNOW
POSSIBLE ON THE RUNWAYS. LIGHT SNOW WILL CONTINUE INTO MONDAY
MORNING.
KPUB...VFR CONDITIONS THROUGH MID AFTERNOON WITH A COLD FRONT
DROPPING SOUTH ACROSS THE TERMINAL LATER THIS AFTERNOON. STRATUS
WILL FILL IN BEHIND THE COLD FRONT. INITIALLY RAIN...CHANGING TO
SNOW IS FORECAST THIS EVENING WITH SNOW PERSISTING OVERNIGHT.
MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1034 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 903 AM MST SUN JAN 11 2015
UPDATED TO EXPIRE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY.
OBSERVATIONS INDICATE A FEW AREAS OF FOG STILL PERSIST AND WILL
CONTINUE TO PRODUCE REDUCED VISIBILITIES THROUGH NOON. MOZLEY
UPDATE ISSUED AT 724 AM MST SUN JAN 11 2015
MADE ADJUSTMENTS TO PRIMARILY NEAR-TERM GRIDS AS WELL AS SOME OF
THE SHORT-TERM GRIDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1029 AM MST SUN JAN 11 2015
KALS...LOW STRATUS WILL PERSIST ACROSS THE SAN LUIS VALLEY THROUGH
MONDAY MORNING. EXPECT FOG TO REDEVELOP THIS EVENING WITH IFR TO
LIFR CONDITIONS DUE TO LOWERED CIGS AND VIS. SNOW SHOWERS OVER THE
MOUNTAINS COULD MOVE INTO THE VALLEY AND MAY BRIEFLY IMPACT THE
TERMINAL TONIGHT.
KCOS...A COLD FRONT IS CURRENTLY DROPPING SOUTH OVER THE PALMER
DIVIDE WITH LOW STRATUS AND SNOW EXPECTED TO DEVELOP OVER THE
TERMINAL THROUGH THIS AFTERNOON. MODEL GUIDANCE SUGGESTS SNOW WILL
BE HEAVIEST BETWEEN 03-08Z TONIGHT WITH A COUPLE OF INCHES OF SNOW
POSSIBLE ON THE RUNWAYS. LIGHT SNOW WILL CONTINUE INTO MONDAY
MORNING.
KPUB...VFR CONDITIONS THROUGH MID AFTERNOON WITH A COLD FRONT
DROPPING SOUTH ACROSS THE TERMINAL LATER THIS AFTERNOON. STRATUS
WILL FILL IN BEHIND THE COLD FRONT. INITIALLY RAIN...CHANGING TO
SNOW IS FORECAST THIS EVENING WITH SNOW PERSISTING OVERNIGHT.
MOZLEY
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AVIATION...MOZLEY
AREA FORECAST DISCUSSION
NWS PUEBLO CO
912 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 903 AM MST SUN JAN 11 2015
UPDATED TO EXPIRE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY.
OBSERVATIONS INDICATE A FEW AREAS OF FOG STILL PERSIST AND WILL
CONTINUE TO PRODUCE REDUCED VISIBILITIES THROUGH NOON. MOZLEY
UPDATE ISSUED AT 724 AM MST SUN JAN 11 2015
MADE ADJUSTMENTS TO PRIMARILY NEAR-TERM GRIDS AS WELL AS SOME OF
THE SHORT-TERM GRIDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM MST SUN JAN 11 2015
PRIMARY NEAR/SHORT TERM METEOROLOGICAL ISSUES/CHALLENGES INCLUDE
INCREASING POTENTIAL FOR PRECIPITATION(ESPECIALLY OVER PORTIONS OF
TELLER AND EL PASO COUNTIES AS WELL AS SECTIONS OF THE CONTINENTAL
DIVIDE) FROM LATER TODAY INTO TONIGHT...TEMPERATURES AND FOG
POTENTIAL.
OUTSIDE OF THE SAN LUIS VALLEY(WHERE FOG HAS BEEN OBSERVED) MAJORITY
OF FORECAST DISTRICT CURRENTLY GRACED BY SOME VARIABLE CLOUDS IN
COMBINATION WITH ABOVE SEASONAL EARLY MORNING TEMPERATURES.
WILL CONTINUE THE DENSE FOG ADVISORY FOR THE SAN LUIS VALLEY UNTIL
AT LEAST 9 AM MST TODAY AS FOG OBSERVED OVER THIS REGION EARLY THIS
MORNING AND IS EXPECTED TO CONTINUE THROUGH THIS TIME-FRAME.
HAVE INCREASED POPS FROM LATER TODAY INTO TONIGHT...ESPECIALLY OVER
PORTIONS OF TELLER AND EL PASO COUNTIES AS RECENT REAL-TIME
DATA...COMPUTER SIMULATIONS AND FORECAST SOUNDINGS SUPPORT
PRECIPITATION OVER THIS REGION IN WAKE OF NORTHERLY SURGE MOVING
ACROSS EASTERN COLORADO TODAY AND SOME UPPER LIFT.
RECENT HRRR SUGGESTS THAT NORTHERLY SURGE OVER EASTERN PORTIONS OF
THE FORECAST DISTRICT WILL BE ENTERING NORTHEASTERN NEW MEXICO BY
THIS AFTERNOON WITH PRECIPITATION DEVELOPING OVER PORTIONS OF TELLER
AND EL PASO COUNTIES LATER TODAY AND INCREASING IN COVERAGE AND
INTENSITY TONIGHT.
FOR NOW...HAVE DEPICTED SNOW AMOUNTS TODAY OVER SECTIONS OF THE
CONTINENTAL DIVIDE IN THE ONE TO THREE INCH RANGE...WITH LOWER
SNOW AMOUNTS OVER OUR REMAINING MOUNTAINS.
FOR TONIGHT...HAVE DEPICTED UP TO FOUR INCHES OF SNOW OVER PIKES
PEAK WITH ONE TO THREE INCHES OF SNOW ANTICIPATED OVER NORTHERN EL
PASO COUNTY(LOCALLY HEAVIER SNOW WILL BE POSSIBLE) AND LOWER SNOW
AMOUNTS ELSEWHERE.
IF HEAVIER SNOW TRENDS DEVELOP...WINTER WEATHER HIGHLIGHTS MAY
BECOME NECESSARY TONIGHT...WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
HAVE ALSO INTRODUCED FOG OVER PORTIONS OF THE INTERSTATE 25 CORRIDOR
AS WELL AS THE SOUTHEASTERN COLORADO PLAINS AND THE SAN LUIS VALLEY
TONIGHT.
FINALLY...MAJORITY OF FORECAST DISTRICT SHOULD NOTE MAXIMUM AND
MINIMUM TEMPERATURES RUNNING ABOVE MID-JANUARY CLIMATOLOGICAL
AVERAGES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM MST SUN JAN 11 2015
LOW LEVEL UPSLOPE FLOW AND ABUNDANT LOW LEVEL MSTR OVR THE SERN
PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS ON MON...IS EXPECTED TO
LEAD TO A LOT OF LOW CLOUDS AND THE CHANCE FOR LIGHT SNOWFALL ALONG
WITH AREAS OF FOG. WITH A COLD AIR MASS IN PLACE AND ALL THE CLOUD
COVER...TEMPS ACRS THE ERN PLAINS SHOULD MAINLY BE IN THE 20S ON
MON. IT ALSO LOOKS LIKE THE SAN LUIS VALLEY WILL SEE LOW CLOUDS AND
FOG MON MORNING. THE REST OF THE FORECAST AREA ON MON SHOULD SEE
MAINLY CLOUDY SKIES AND THE POTENTIAL FOR ISOLD TO SCT PCPN.
THE LOW CLOUDS AND POTENTIAL FOR LIGHT SNOWFALL SHOULD CONTINUE OVR
THE SERN PLAINS AND LOWER EAST SLOPES OF THE ERN MTNS THROUGH MON
NIGHT. MON NIGHT AN UPR TROF WL MOVE ACRS UT AND WL BRING AN
INCREASE IN MSTR TO THE WRN HALF OF THE STATE...ALONG WITH SNOW
ACCUMULATIONS TO THE CONTDVD AND ERN MTNS. THE ERN SAN JUAN MTNS
SHOULD SEE THE HIGHEST SNOW ACCUMULATIONS. LOW LEVEL SOUTHERLY
FLOW IN THE SAN LUIS VALLEY WILL HAVE THE POTENTIAL FOR BRING SNOW
ACCUMULATIONS TO NRN PORTIONS OF THE VALLEY.
TUE THE LOW LEVEL MSTR CONTINUES TO KEEP THE SERN PLAINS CLOUDY AND
COLD WITH HIGHS AGAIN ONLY BEING IN THE 20S. DURING THE DAY THE UPR
TROF MOVES OVR CO AND SPREADS PCPN CHANCES EASTWARD ACRS THE
STATE...WITH THE CONTDVD STILL EXPECTED TO SEE THE HIGHER
ACCUMULATIONS. WL LIKELY NEED WINTER WX HIGHLIGHT FOR AT LEAST THE
SW MTNS...BUT IT IS A LITTLE TOO EARLY TO ISSUE AT THIS TIME. THE
UPR TROF REMAINS OVR THE STATE TUE NIGHT...ALONG WITH CHANCES FOR
PCPN. THE NAM SHOWS THE BEST PCPN CHANCES OVR THE MTNS AREAS TUE
NIGHT...AND PORTIONS OF THE NRN SAN LUIS VALLEY.
FOR WED THE UPR TROF MOVES S AND E OF THE AREA...WITH PCPN CHANCES
ENDING ALONG WITH DECREASING CLOUD COVER AND TEMPS GETTING A LITTLE
WARMER. AN UPR RIDGE BUILDS OVR THE AREA FOR THU RESULTING IN DRY
AND WARMER WX...WITH HIGH TEMPS BEING AROUND NORMAL. THU NIGHT A
SHORTWAVE TROF IS FORECAST TO MOVE THRU THE AREA...BUT THE WEATHER
LOOKS TO STAY DRY AS THE UPR RIDGE REBOUNDS DURING THE DAY FRI. FOR
NEXT WEEKEND WESTERLY FLOW ALOFT IS EXPECTED ON SATURDAY...
TRANSITIONING TO SW FLOW ON SUN AS AN UPR TROF MOVES INTO THE
WESTERLY SATES ON SUNDAY. THE WEATHER LOOKS DRY FOR THE
WEEKEND...ALONG WITH HIGH TEMPS THAT ARE AROUND TO SLIGHTLY WARMER
THAN AVERAGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 355 AM MST SUN JAN 11 2015
FOR KALS...LOW CLOUDS AND AREAS OF DENSE FOG ARE EXPECTED INTO MID-
MORNING WITH CONDITIONS THEN IMPROVING BEFORE ANOTHER ROUND OF LOW
CLOUDS AND FOG DEVELOP AGAIN TONIGHT.
FOR KCOS AND KPUB...OTHER THAN SOME LOCALIZED LOW CLOUDS AND FOG
EARLY THIS MORNING...VFR CONDITIONS ARE ANTICIPATED TODAY BEFORE
CONDITIONS DETERIORATE BY TONIGHT IN THE WAKE OF A COLD FRONT MOVING
ACROSS SOUTHEASTERN COLORADO TODAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
200 PM CST SUN JAN 11 2015
.SHORT TERM...
325 AM CST
THROUGH MONDAY NIGHT...
UPPER LEVEL FLOW IS ZONAL WITH A SHORTWAVE TROUGH OVER TX. THE WAVE
WEAKENS AS IT MOVES OVER CENTRAL IL THIS EVENING. A SECOND SHORTWAVE
IS OVER THE DESERT SOUTHWEST AND IT WILL WEAKEN AS IT MOVES OVER THE
REGION MONDAY MORNING. AN UPPER LEVEL TROUGH IS STRETCHED OUT OVER
SOUTHERN CANADA AND IT/S TROUGH AXIS PASSES THROUGH THE REGION
MONDAY NIGHT.
A SURFACE HIGH IS OVER THE CENTRAL ATLANTIC COAST WHILE A WEAK
TROUGH/COLD FRONT STRETCHES FROM IOWA THROUGH SOUTHERN ONTARIO. THE
TROUGH/COLD FRONT WILL SAG SOUTH OVER THE CWA LATE THIS AFTERNOON
INTO THIS EVENING WHILE THE WEAK SURFACE LOW ASSOCIATED WITH THE
TROUGH SHIFTS NORTHEAST INTO SOUTHWEST QUEBEC. THE OTHER PLAYER IS
A LARGE HIGH PRESSURE SYSTEM CURRENTLY OVER SOUTHWEST CANADA WILL
SHIFT SOUTHEAST REACHING THE NORTHERN PLAINS TONIGHT BEFORE MOVING
OVER OUR NECK OF THE WOODS TUESDAY.
MOISTURE SURGES NORTH WITH THE FIRST SHORTWAVE TROUGH THIS AFTERNOON
AND EVENING. THERE SHOULD BE AMPLE LIFT FROM THE ON GOING WAA AND
ALONG THE TROUGH/COLD FRONT. GUIDANCE CONTINUES TO FEATURE A BAND
OF DECENT FRONTOGENESIS SINKING SOUTHEAST THROUGH THE CWA THIS
EVENING. THE NAM IS MORE EXCITED ABOUT THE FORCING THAN THE GFS.
THE NAM FEATURES A STRONG BAND STRETCHING FROM CHICAGO THROUGH LA
SALLE AT MIDNIGHT THAT QUICKLY SHIFTS SOUTHEAST TO A DETROIT MI TO
GIBSON CITY IL LINE BY 6AM MONDAY. THE GFS SHOWS A SIMILAR
PROGRESSION...JUST WEAKER. WHILE THE BAND IS IMPRESSIVE...OTHER
FACTORS SUCH AS EPV ARE MISSING SO I AM NOT EXCITED ABOUT INTENSE
BANDS OF SNOW. THAT BEING SAID...SOME ENHANCED BANDS OF SNOW MAY
FORM LEADING TO LOCALIZED HIGHER SNOW TOTALS.
PRECIP SPREADS NORTH THIS AFTERNOON WITH PRECIP FALLING SOUTH OF A
WAUKEGAN TO ROCKFORD LINE BY 6PM CST. EXPECTING SNOW FOR ALL AREAS
EXCEPT THOSE SOUTH OF A PONTIAC IL TO RENSSELAER INDIANA LINE.
SOUNDINGS SOUTH OF THIS LINE FEATURE PARTIAL MELTING ALOFT THAT MAY
LEAD TO SLEET MIXED WITH SNOW. NOT SURE HOW LONG SLEET OR A MIX OF
SLEET AND SNOW WILL FALL SOUTH OF THIS LINE AS COOLING MAY HELP THE
PRECIP TURN OVER TO ALL SNOW SOONER THAN FORECAST. IF THAT
HAPPENS...SNOW AMOUNTS WILL BE HIGHER THAN CURRENTLY FORECAST.
FOR THE AREAS NORTH OF THE PONTIAC TO RENSSELAER LINE...STEADY LIGHT
TO MODERATE SNOW IS EXPECTED THROUGH THE EVENING. A FEW BANDS OF
MODERATE TO POSSIBLY HEAVY SNOW MAY FORM ALONG AND SOUTH OF A
CHICAGO TO LA SALLE LINE AFTER MIDNIGHT. EXPECTING ALL SNOW ACROSS
THE CWA AFTER MIDNIGHT AND THE SNOW SLOWLY EXITS TO THE SOUTHEAST
THROUGH MID MONDAY MORNING.
HAVE LOWER STORM TOTAL SNOWFALL AMOUNTS THAN THE PREVIOUS FORECAST
DUE TO LESS CONFIDENCE IN BANDS OF HEAVIER SNOW AND HIGHER
CONFIDENCE IN SLEET MIXED WITH SNOW IN THE SOUTHERN CWA. EXPECTING
1 TO 2 INCHES ALONG AND SOUTH OF A OHARE TO AMBOY LINE WITH 1 TO
3...MAYBE LOCALIZED 4 INCHES SOUTH OF A GARY INDIANA TO LA SALLE
LINE.
WINDS TURN NORTH MONDAY LEADING TO THE POSSIBILITY OF LAKE EFFECT
SNOW OVER NW INDIANA MONDAY. STILL NOT OVERLY IMPRESSED WITH THE
LAKE EFFECT SET UP AS WELL WITH VERY MARGINAL DELTA T/S...DRY
FORECAST SOUNDINGS...AND SOME ICE OVER THE LAKE. AS SUCH CAPPED
POPS IN THE CHANCE RANGE. WINDS VEER TO NORTHEAST MONDAY EVENING
AND THE BAND OF SNOW SHIFTS WEST TO OVER ILLINOIS.
TEMPS MONDAY WILL VARY FROM THE MID TEENS OVER NORTH CENTRAL IL TO
THE MID 20S OVER NW INDIANA. LOWS WILL VARY FROM AROUND +10
DOWNTOWN TO 0 TO +5 IN OUTLYING AREAS. SOME ISOLATED LOCATIONS MAY
DIP BELOW ZERO.
JEE
&&
.LONG TERM...
325 AM CST
TUESDAY THROUGH SATURDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE CONUS TUESDAY WITH TROUGH
AXES/SHORTWAVES MOVING THROUGH THE REGION TUESDAY...WEDNESDAY AND
THURSDAY. THE SURFACE HIGH SITS OVER THE CWA TUESDAY AND SLOWLY
SINKS SOUTH WEDNESDAY. A CLIPPER SYSTEM PASSES TO OUR NORTH
WEDNESDAY NIGHT INTO THURSDAY WITH ANOTHER SURFACE HIGH MOVING OVER
THE REGION LATE IN THE WEEK.
LOOKING AT A DRY REST OF THE WEEK WITH HIGH TEMPS IN THE TEENS
TUESDAY AND WEDNESDAY. THEN WE GET INTO A WARMING TREND WITH AT OR
SLIGHTLY ABOVE FREEZING HIGH TEMPS BY THE END OF THE WEEK. THE ONLY
REALLY COLD NIGHT IS TUESDAY NIGHT WITH LOWS BETWEEN 0 AND -10 AWAY
FROM THE CITY BUT LIGHT WINDS WILL KEEP WIND CHILLS WARMER THAN
-20.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SNOW DEVELOPING BETWEEN 5-7 PM THIS EVENING. BRIEF (APPROX 1
HR) PERIOD OF VERY LGT SNOW/FLURRIES EXPECTED BEFORE MAIN SNOW
AREA... BETWEEN 3-4 PM AT MDW AND 4-5 PM AT ORD.
* HIGHLY VARYING VSBYS... CIGS... AND SNOW RATE/INTENSITY DURING
THIS EVENT.
* IFR VSBY WITH PERIODIC LIFR POSSIBLE IN VARIABLE BANDS OF SNOW.
CIGS LOWER TO MVFR/IFR THIS EVENING.
* SOUTH TO SOUTHWEST WINDS TURN NORTHWEST OVERNIGHT AND INCREASE
OUT OF THE NORTH MONDAY.
ED F
//DISCUSSION...UPDATED 18Z...
WET SNOW TO COMMENCE AROUND THE 23Z (MDW) AND 00Z (ORD) HOUR WITH
CIGS AND VSBYS TO LOWER QUICKLY WITH SNOW ONSET AS IT SPREADS FROM
SOUTH TO NORTH. THIS EVENT CONTINUES TO APPEAR THAT IT WILL POSSES
A BANDED NATURE OF THE SNOW BANDS... WHICH MAY RESULT IN HEAVIER
SNOW/HIGHER ACCUMULATIONS WHERE THE HEAVIER BANDS SET UP. OTHER
THAN THAT...GENERALLY SPEAKING AREAS TOWARD THE SOUTH AND EAST
WILL POTENTIALLY SEE A LONGER DURATION SNOW EVENT AND HENCE A
HIGHER OVERALL ACCUMULATION. PRECIPITATION TYPE TO REMAIN ALL SNOW
ACROSS THE CHICAGO METRO... BUT SLEET WILL BE ONLY AROUND 50 MILES
SOUTH.
THE TRANSIENT BANDED NATURE OF THE SNOW CONTINUES TO THUS
SUGGESTED HIGH VARIABILITY IN CIGS AND ESPECIALLY VSBYS THROUGHOUT
THE COURSE OF THE EVENING. SEEING SOME AGREEMENT AND CONSISTENCY
IN THE HIGH RESOLUTION MODELS FOR TWO SEPARATE BEST PERIODS OF
OPPORTUNITY FOR BRIEF PERIODS OF HEAVIER SNOW (45-90 MINUTE
DURATION EACH) PERHAPS CENTERED AROUND THE 23Z-01Z AND 03Z-05Z
TIME FRAMES. HAVE HIGHLIGHTED THESE WINDOWS FOR EXPECTED POORER
CONDITIONS IN THE TAFS... HOWEVER IDENTIFYING THESE WINDOWS
REMAINS A CHALLENGE AND IS SUBJECT TO CHANGE.
RFD EXPECTED TO REMAIN JUST NORTH OF THE SNOW BUT MAY SEE A BRIEF
DURATION VERY LIGHT ACCUMULATION. SOUTH TO SOUTHWEST WIND WILL
TURN NORTHWEST TO NORTH OVERNIGHT BEHIND A COLD FRONT. EXPECT MVFR
CIGS TO LIFT TO VFR BY SUNRISE WITH DRYER AIR SPREADING IN BEHIND
THE FRONT.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN SNOW... MEDIUM TO HIGH CONFIDENCE IN TIMING.
* HIGH CONFIDENCE THAT CONDITIONS WILL BE HIGHLY VARIABLE... LOW
CONFIDENCE ON SPECIFIC TIMING AND DURATION OF POOREST (VSBYS AND
CIGS) CONDITIONS.
* HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS POSSIBLE. A CHANCE OF LIGHT SNOW SHOWERS. NORTH
WINDS.
TUESDAY...MVFR CIGS POSSIBLE. NORTHEAST-EAST WINDS.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR. SOUTHWEST TO WEST
WINDS.
MDB
&&
.MARINE...
254 AM CST
WEAK LOW PRESSURE IS MOVING ACROSS UPPER MICHIGAN THIS MORNING WITH
A TROUGH AXIS/COLD FRONT TRAILING IT TO THE SOUTHWEST. STRONG HIGH
PRESSURE OVER THE CAROLINA COAST WILL SHIFT OFFSHORE THROUGH THE DAY
ALLOWING THE SURFACE TROUGH TO SAG SOUTHEASTWARD INTO TONIGHT. THE
FAIRLY STRONG PRESSURE GRADIENT ACROSS LAKE MICHIGAN EARLY THIS
MORNING CONTINUES TO GENERATE STEADY WINDS BUT SPEEDS WILL STEADILY
DIMINISH THROUGH THE MORNING AS THE PRESSURE GRADIENT WEAKENS. WINDS
WILL SHIFT TO THE NORTHWEST TONIGHT AS THE FRONT PASSES WITH A
FURTHER SHIFT TO THE NORTH OCCURRING MONDAY MORNING. STRONG HIGH
PRESSURE ACROSS CENTRAL CANADA THIS MORNING WILL STRENGTHEN AS IT
MOVES SOUTHEAST INTO THE EASTERN DAKOTAS OVERNIGHT. AS A
RESULT...SPEEDS WILL PICK UP WITH GUSTS TO AROUND 25 KT LIKELY WITH
SOME CLOSER TO 30 KT POSSIBLE AT TIMES DURING THE DAY MONDAY BEFORE
WINDS TURN MORE TO THE NORTHEAST AND EASE MONDAY EVENING/NIGHT AS
THE HIGH SPREADS ACROSS THE LAKES.
THE HIGH WILL SHIFT SOUTH OF THE GREAT LAKES LATER WEDNESDAY. A
SERIES OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK ACROSS SOUTHERN
CANADA AND THE NORTHERN TIER OF STATES INTO LATE WEEK LEADING TO
PERIODIC WIND SHIFTS AND INCREASES IN SPEED.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1158 AM CST Sun Jan 11 2015
.UPDATE...
ISSUED AT 1045 AM CST SUN JAN 11 2015
Will continue the winter weather advisory from this afternoon
until 9 am Monday morning from Lincoln and Rantoul south for a
wintery mix of precipitation. Have nudged temperatures up a bit
today as current mercury levels running 1-2 degrees warmer with
most areas in the lower 30s (ranging from 29F at Galesburg to 36
at Mount Carmel airport). But low dewpoints in the mid teens to
lower 20s with wet bulb zero readings in the mid to upper 20s will
cause temps to slip back 1-2F as precipitation moves in from the
south during this afternoon. Radar shows a narrow band of light
precipitation lifting north of I-72 but most of this appears to be
virga with dry low levels. Litchfield had a 1-2 hour period of
light sleet with this band earlier this morning. Main area of
precipitation is lifting northward into southern IL (south of
I-64) and should overspread central/se IL during the afternoon.
Have brought in a mix of light freezing rain and light rain into
southeast IL southeast of I-70 this afternoon which continues into
this evening and this could lower their ice accumulations south of
I-70. Light snow and sleet expected to develop north of winter wx
advisory area in frontogenetic band setting up over the IL river
valley later this afternoon, with half to 1 inch of snow by dusk.
Mixture of light freezing rain and sleet expected over heart of
central IL especially from Lincoln south to I-70 with ice
accumulations generally less than a tenth of an inch through dusk.
More snow and ice acculuations expected tonight with 1-2 inches north
and one to two tenths inch ice central sections and less than a
tenth inch of ice southeast of I-70 near highway 50 in southern 3
counties.
&&
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1155 AM CST SUN JAN 11 2015
VFR ceilings of 3.5-5K feet at midday will lower to MVFR ceilings
during next few hours as mixed light precipitation develops
northward. Visibilities to also lower to MVFR during the afternoon
as light freezing rain and sleet develops along I-72 with light
snow and sleet further north at PIA and BMI. Ceilings to drop
below 1k ft during this evening with vsbys down to 1-2 miles with
mixed precipitation gradually changing to light snow along I-72
during overnight. Models show low clouds decrease from nw to se
behind cold front during Monday morning and linger longest at CMI
and DEC which currently kept them in MVFR ceilings through the
morning. South winds near 10 kts this afternoon to become lighter
this evening and then switch to the north overnight and increase
to 10-14 kts with gusts of 15-20 kts during Monday morning.
Weak 1020 mb surface low pressure over nw Gulf of Mexico to lift
ne across the southeast states through tonight while increasing
isentropic lift and moisture into central IL this afternoon and
evening. Associated short wave over MO/AR to lift nne across IL
into tonight and help develop the mixed precipitation this
afternoon and tonight, then ending Monday morning as it shifts se
of central IL. Strong 1048 mb arctic high pressure pushing into
the eastern Dakotas by 18Z/noon Monday to return tight pressure
gradient over IL with brisk northerly winds developing Monday
morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 9 AM CST Monday FOR ILZ042>057-
061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1048 AM CST SUN JAN 11 2015
.SHORT TERM...
325 AM CST
THROUGH MONDAY NIGHT...
UPPER LEVEL FLOW IS ZONAL WITH A SHORTWAVE TROUGH OVER TX. THE WAVE
WEAKENS AS IT MOVES OVER CENTRAL IL THIS EVENING. A SECOND SHORTWAVE
IS OVER THE DESERT SOUTHWEST AND IT WILL WEAKEN AS IT MOVES OVER THE
REGION MONDAY MORNING. AN UPPER LEVEL TROUGH IS STRETCHED OUT OVER
SOUTHERN CANADA AND IT/S TROUGH AXIS PASSES THROUGH THE REGION
MONDAY NIGHT.
A SURFACE HIGH IS OVER THE CENTRAL ATLANTIC COAST WHILE A WEAK
TROUGH/COLD FRONT STRETCHES FROM IOWA THROUGH SOUTHERN ONTARIO. THE
TROUGH/COLD FRONT WILL SAG SOUTH OVER THE CWA LATE THIS AFTERNOON
INTO THIS EVENING WHILE THE WEAK SURFACE LOW ASSOCIATED WITH THE
TROUGH SHIFTS NORTHEAST INTO SOUTHWEST QUEBEC. THE OTHER PLAYER IS
A LARGE HIGH PRESSURE SYSTEM CURRENTLY OVER SOUTHWEST CANADA WILL
SHIFT SOUTHEAST REACHING THE NORTHERN PLAINS TONIGHT BEFORE MOVING
OVER OUR NECK OF THE WOODS TUESDAY.
MOISTURE SURGES NORTH WITH THE FIRST SHORTWAVE TROUGH THIS AFTERNOON
AND EVENING. THERE SHOULD BE AMPLE LIFT FROM THE ON GOING WAA AND
ALONG THE TROUGH/COLD FRONT. GUIDANCE CONTINUES TO FEATURE A BAND
OF DECENT FRONTOGENESIS SINKING SOUTHEAST THROUGH THE CWA THIS
EVENING. THE NAM IS MORE EXCITED ABOUT THE FORCING THAN THE GFS.
THE NAM FEATURES A STRONG BAND STRETCHING FROM CHICAGO THROUGH LA
SALLE AT MIDNIGHT THAT QUICKLY SHIFTS SOUTHEAST TO A DETROIT MI TO
GIBSON CITY IL LINE BY 6AM MONDAY. THE GFS SHOWS A SIMILAR
PROGRESSION...JUST WEAKER. WHILE THE BAND IS IMPRESSIVE...OTHER
FACTORS SUCH AS EPV ARE MISSING SO I AM NOT EXCITED ABOUT INTENSE
BANDS OF SNOW. THAT BEING SAID...SOME ENHANCED BANDS OF SNOW MAY
FORM LEADING TO LOCALIZED HIGHER SNOW TOTALS.
PRECIP SPREADS NORTH THIS AFTERNOON WITH PRECIP FALLING SOUTH OF A
WAUKEGAN TO ROCKFORD LINE BY 6PM CST. EXPECTING SNOW FOR ALL AREAS
EXCEPT THOSE SOUTH OF A PONTIAC IL TO RENSSELAER INDIANA LINE.
SOUNDINGS SOUTH OF THIS LINE FEATURE PARTIAL MELTING ALOFT THAT MAY
LEAD TO SLEET MIXED WITH SNOW. NOT SURE HOW LONG SLEET OR A MIX OF
SLEET AND SNOW WILL FALL SOUTH OF THIS LINE AS COOLING MAY HELP THE
PRECIP TURN OVER TO ALL SNOW SOONER THAN FORECAST. IF THAT
HAPPENS...SNOW AMOUNTS WILL BE HIGHER THAN CURRENTLY FORECAST.
FOR THE AREAS NORTH OF THE PONTIAC TO RENSSELAER LINE...STEADY LIGHT
TO MODERATE SNOW IS EXPECTED THROUGH THE EVENING. A FEW BANDS OF
MODERATE TO POSSIBLY HEAVY SNOW MAY FORM ALONG AND SOUTH OF A
CHICAGO TO LA SALLE LINE AFTER MIDNIGHT. EXPECTING ALL SNOW ACROSS
THE CWA AFTER MIDNIGHT AND THE SNOW SLOWLY EXITS TO THE SOUTHEAST
THROUGH MID MONDAY MORNING.
HAVE LOWER STORM TOTAL SNOWFALL AMOUNTS THAN THE PREVIOUS FORECAST
DUE TO LESS CONFIDENCE IN BANDS OF HEAVIER SNOW AND HIGHER
CONFIDENCE IN SLEET MIXED WITH SNOW IN THE SOUTHERN CWA. EXPECTING
1 TO 2 INCHES ALONG AND SOUTH OF A OHARE TO AMBOY LINE WITH 1 TO
3...MAYBE LOCALIZED 4 INCHES SOUTH OF A GARY INDIANA TO LA SALLE
LINE.
WINDS TURN NORTH MONDAY LEADING TO THE POSSIBILITY OF LAKE EFFECT
SNOW OVER NW INDIANA MONDAY. STILL NOT OVERLY IMPRESSED WITH THE
LAKE EFFECT SET UP AS WELL WITH VERY MARGINAL DELTA T/S...DRY
FORECAST SOUNDINGS...AND SOME ICE OVER THE LAKE. AS SUCH CAPPED
POPS IN THE CHANCE RANGE. WINDS VEER TO NORTHEAST MONDAY EVENING
AND THE BAND OF SNOW SHIFTS WEST TO OVER ILLINOIS.
TEMPS MONDAY WILL VARY FROM THE MID TEENS OVER NORTH CENTRAL IL TO
THE MID 20S OVER NW INDIANA. LOWS WILL VARY FROM AROUND +10
DOWNTOWN TO 0 TO +5 IN OUTLYING AREAS. SOME ISOLATED LOCATIONS MAY
DIP BELOW ZERO.
JEE
&&
.LONG TERM...
325 AM CST
TUESDAY THROUGH SATURDAY...
A BROAD UPPER LEVEL TROUGH SPANS THE CONUS TUESDAY WITH TROUGH
AXES/SHORTWAVES MOVING THROUGH THE REGION TUESDAY...WEDNESDAY AND
THURSDAY. THE SURFACE HIGH SITS OVER THE CWA TUESDAY AND SLOWLY
SINKS SOUTH WEDNESDAY. A CLIPPER SYSTEM PASSES TO OUR NORTH
WEDNESDAY NIGHT INTO THURSDAY WITH ANOTHER SURFACE HIGH MOVING OVER
THE REGION LATE IN THE WEEK.
LOOKING AT A DRY REST OF THE WEEK WITH HIGH TEMPS IN THE TEENS
TUESDAY AND WEDNESDAY. THEN WE GET INTO A WARMING TREND WITH AT OR
SLIGHTLY ABOVE FREEZING HIGH TEMPS BY THE END OF THE WEEK. THE ONLY
REALLY COLD NIGHT IS TUESDAY NIGHT WITH LOWS BETWEEN 0 AND -10 AWAY
FROM THE CITY BUT LIGHT WINDS WILL KEEP WIND CHILLS WARMER THAN
-20.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SNOW SPREADING NORTH/MOVING IN LATE THIS AFTERNOON/EARLY THIS
EVENING...ENDING OVERNIGHT.
* IFR VSBY WITH PERIODIC LIFR POSSIBLE IN VARIABLE BANDS OF SNOW.
CIGS LOWER TO MVFR/IFR THIS EVENING.
* SOUTH TO SOUTHWEST WINDS TURN NORTHWEST EARLY TONIGHT AND
INCREASE OUT OF THE NORTH MONDAY.
ED F
//DISCUSSION...UPDATED 12Z...
VFR CONDITIONS WILL CONTINUE THROUGH THE DAY BEFORE DETERIORATING
LATE THIS AFTERNOON AND THIS EVENING AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE REGION. SNOW WILL SPREAD NORTHWARD ACROSS THE
TERMINALS LATE THIS AFTERNOON THROUGH THE EVENING...THEN COME TO
AN END OVERNIGHT. RFD WILL LIKELY REMAIN JUST NORTH OF THE SNOW
BAND BUT WILL CONTINUE WITH A PROB30 MENTION FOR NOW.
OTHERWISE...SNOW MAY FALL IN SEVERAL BANDS WHICH SUGGESTS THAT
THERE MAY BE A HIGH DEGREE OF VARIABILITY IN CIGS AND ESPECIALLY
VSBY. SNOW WILL PROBABLY FALL CONTINUOUSLY FOR THE MOST PART BUT
INTENSITY MAY FLUCTUATE QUITE A BIT. HAVE GOOD CONFIDENCE IN THE
OVERALL TIME WINDOW FOR SNOWFALL BUT THE DETAILS SUCH AS
IDENTIFYING THE BEST WINDOW FOR LOWEST VSBY REMAINS A
CHALLENGE...TANKS TO THE TRANSIENT NATURE OF THE EXPECTED
BANDS. SOUTH TO SOUTHWEST WINDS WILL PREVAIL INTO THE EVENING AS
WELL BEFORE TURNING WEST THEN NORTHWEST TONIGHT BEHIND A FRONT.
MVFR CIGS MAY END UP PREVAILING INTO MONDAY MORNING BUT THERE IS
ALSO SUPPORT FOR LESS MVFR COVERAGE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN SNOW OCCURRING THIS EVENING. HIGH CONFIDENCE
IN START TIME. MEDIUM-HIGH CONFIDENCE IN END TIME.
* HIGH CONFIDENCE IN IFR VSBY OCCURRING IN SNOW WITH MEDIUM
CONFIDENCE IN LIFR VSBY OCCURRING INTERMITTENTLY. LOW CONFIDENCE
IN DURATION OF LIFR VSBY. HIGH CONFIDENCE IN CIG TRENDS THROUGH
THE EVENING. MEDIUM CONFIDENCE IN CIG TRENDS OVERNIGHT.
* HIGH CONFIDENCE IN WIND TRENDS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...MVFR CIGS POSSIBLE. A CHANCE OF LIGHT SNOW SHOWERS. NORTH
WINDS.
TUESDAY...MVFR CIGS POSSIBLE. NORTHEAST-EAST WINDS.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR. SOUTHWEST TO WEST
WINDS.
MDB
&&
.MARINE...
254 AM CST
WEAK LOW PRESSURE IS MOVING ACROSS UPPER MICHIGAN THIS MORNING WITH
A TROUGH AXIS/COLD FRONT TRAILING IT TO THE SOUTHWEST. STRONG HIGH
PRESSURE OVER THE CAROLINA COAST WILL SHIFT OFFSHORE THROUGH THE DAY
ALLOWING THE SURFACE TROUGH TO SAG SOUTHEASTWARD INTO TONIGHT. THE
FAIRLY STRONG PRESSURE GRADIENT ACROSS LAKE MICHIGAN EARLY THIS
MORNING CONTINUES TO GENERATE STEADY WINDS BUT SPEEDS WILL STEADILY
DIMINISH THROUGH THE MORNING AS THE PRESSURE GRADIENT WEAKENS. WINDS
WILL SHIFT TO THE NORTHWEST TONIGHT AS THE FRONT PASSES WITH A
FURTHER SHIFT TO THE NORTH OCCURRING MONDAY MORNING. STRONG HIGH
PRESSURE ACROSS CENTRAL CANADA THIS MORNING WILL STRENGTHEN AS IT
MOVES SOUTHEAST INTO THE EASTERN DAKOTAS OVERNIGHT. AS A
RESULT...SPEEDS WILL PICK UP WITH GUSTS TO AROUND 25 KT LIKELY WITH
SOME CLOSER TO 30 KT POSSIBLE AT TIMES DURING THE DAY MONDAY BEFORE
WINDS TURN MORE TO THE NORTHEAST AND EASE MONDAY EVENING/NIGHT AS
THE HIGH SPREADS ACROSS THE LAKES.
THE HIGH WILL SHIFT SOUTH OF THE GREAT LAKES LATER WEDNESDAY. A
SERIES OF LOW PRESSURE SYSTEMS ARE EXPECTED TO TRACK ACROSS SOUTHERN
CANADA AND THE NORTHERN TIER OF STATES INTO LATE WEEK LEADING TO
PERIODIC WIND SHIFTS AND INCREASES IN SPEED.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1047 AM CST Sun Jan 11 2015
.UPDATE...
ISSUED AT 1045 AM CST SUN JAN 11 2015
Will continue the winter weather advisory from this afternoon
until 9 am Monday morning from Lincoln and Rantoul south for a
wintery mix of precipitation. Have nudged temperatures up a bit
today as current mercury levels running 1-2 degrees warmer with
most areas in the lower 30s (ranging from 29F at Galesburg to 36
at Mount Carmel airport). But low dewpoints in the mid teens to
lower 20s with wet bulb zero readings in the mid to upper 20s will
cause temps to slip back 1-2F as precipitation moves in from the
south during this afternoon. Radar shows a narrow band of light
precipitation lifting north of I-72 but most of this appears to be
virga with dry low levels. Litchfield had a 1-2 hour period of
light sleet with this band earlier this morning. Main area of
precipitation is lifting northward into southern IL (south of
I-64) and should overspread central/se IL during the afternoon.
Have brought in a mix of light freezing rain and light rain into
southeast IL southeast of I-70 this afternoon which continues into
this evening and this could lower their ice accumulations south of
I-70. Light snow and sleet expected to develop north of winter wx
advisory area in frontogenetic band setting up over the IL river
valley later this afternoon, with half to 1 inch of snow by dusk.
Mixture of light freezing rain and sleet expected over heart of
central IL especially from Lincoln south to I-70 with ice
accumulations generally less than a tenth of an inch through dusk.
More snow and ice acculuations expected tonight with 1-2 inches north
and one to two tenths inch ice central sections and less than a
tenth inch of ice southeast of I-70 near highway 50 in southern 3
counties.
&&
.SHORT TERM...(Today)
ISSUED AT 341 AM CST SUN JAN 11 2015
Warm air surging north ahead of the next cold front will ride up and
over the cold dome of air in place across central IL. 40kt of
isentropic lift along the 300K surface will help the layer of clouds
around 6K FT deepen with time as additional moisture arrives. Light
freezing rain or sleet will advance northward this morning, possibly
reaching our southern counties a little before Noon. At the same
time, a frontogenetical circulation across our northern counties
will work to produce light snow/sleet north of a line from
Bloomington to Havana, and especially from Peoria and north. The
models have shown this band of snow over the past several runs. So
it is possible we could have a region in the central portion of our
forecast area (generally along I-72) remain dry while snow falls
north and freezing rain/sleet falls to the south. Eventually we
should see freezing rain/sleet overspread our central counties up to
I-72 and continue into the evening. 00z/NAM soundings definitely
show a warm bias over the cooler GFS and ECMWF. We trended slightly
warmer with surface temps across the southerly half of the area as a
result, and pushed chances of freezing rain farther north as well.
In light of the northward trend for icing from freezing rain, in
conjunction with snow/sleet later in the event, we expanded the
advisory area northward another row of counties to now include
Champaign and Lincoln. Icing potential from freezing rain could
climb between one and two tenths of an inch toward the I-70
corridor. There is low potential for isolated areas to see a quarter
inch of ice, which is our trigger for an ice storm warning. If the
warmer trend is correct, our southern counties along highway 50
could become all rain later this afternoon and early evening, which
would reduce ice totals as you headed south of I-70.
The 00z/NAM is also indicating an extended period of sleet will be
possible toward I-72. If that developed, we could see 0.5" of sleet,
which is one trigger for a winter storm warning. At this point, we
do not have high enough confidence of widespread areas receiving
0.25" of ice nor 0.5" of sleet to warrant an upgrade to a winter
storm warning. We will keep the headlines as an advisory. QPF
amounts in general do not seem to support ice and sleet
accumulations that high from this event.
Even models generally lower on QPF, there is evidence in the GFS and
NAM of banded precipitation, which could create large variations in
snow/sleet/ice amounts over short distances. There is a 100mb layer
of the Fn convergent portion of frontogenesis across our forecast
area, with negative EPV just above that layer to allow for CSI-type
banding. Pinpointing those bands is difficult even this close to the
event. As hourly HRRR and RAP model updates come in and we compare
to satellite and radar, we will have a better chance to do short
term updates on snow/sleet/ice amounts where bands appear more
likely.
For now, we will stick with snow totals north of I-72 in the 1-2"
range, with ice totals of in the 0.1-0.2" range with the highest
amounts along the I-70 corridor. Sleet totals would reduce snow
amounts along the I-72 corridor and northward. So snowfall totals
will be dependent on how long the airmass supports sleet instead of
transitioning to snow.
High temps today could climb above freezing south of I-70 and
possibly toward Jacksonville. Highs could delay until later this
afternoon when the warmest air aloft reaches its peak between 22z
and 02z. Northern areas should see mainly around 30 for highs. Winds
will be southerly during most of this event, which in general is not
our normal surface wind for a major ice storm due to surface temps
and dewpoints usually rising from south to north in those
situations.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 341 AM CST SUN JAN 11 2015
Tonight after midnight, on the back edge of the storm, normally
would see more snow in the forecast soundings...but even in the wake
of the system, particularly in the east and southeast, warm air in
the mid levels holding on to more sleet potential. Models also
showing the formation of a dry slot now...between the more
frontogenetic banding to the north and the remains of the system.
This may end up taking a chunk out of the QPF for after midnight
depending on the progression of the system. That same drying
starting to show in the column Monday morning as the loss of any
crystals will steer the forecast from snow and wintry mix...to
potential for freezing drizzle. Depending on the speed of the
system, as it has been getting progressively quicker, as well as the
efficacy of the dry slot...the early morning commute on Monday
morning along and south of a line from SPI to DNV may be a bit
messy.
Beyond this weekends system, forecast dries out with high pressure
dominating the weather through next week. Wave digging in over the
western half of the CONUS shearing out the energy moving along the
southern tier of the country, missing the Midwest midweek.
Temperatures at mid levels trying to level out somewhat, but cooler
than climatology continues until a more significant chance for warm
up kicks in next weekend when southerly flow kicks in again on the
back side of exiting high pressure ridge. Same southerly flow
bringing up the next chance for precip for next weekend potentially
from the southwest...and warm enough at this point to trend in some
rain.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 600 AM CST SUN JAN 11 2015
Timing of precip and precip type the main forecast concerns this
period. Next wave of low pressure will start to affect the area this
morning. The current VFR ceilings at 5-6K ft will thicken and
lower during the morning. Some light snow, sleet and freezing rain
are expected to develop across our southern TAF sites (KSPI, KDEC
and KCMI) in the 17z-19z time frame. DEC, SPI, and CMI could
transition to all freezing rain toward mid-afternoon as the warm
layer aloft increases temp to +3C. The northern TAF sites (KBMI
and KPIA) should remain a bit colder, seeing more of a light snow
and sleet mixture develop overhead between 18z- 20z. Once the
precip begins it will be just a matter of an hour or two before we
see cigs drop from low VFR to MVFR, and then IFR/LIFR after
21-22z. Forecast soundings suggest the higher probability for
freezing rain would be from SPI to DEC to near CMI with more of a
sleet and light snow mix further north at BMI, with mostly light
snow expected at PIA. Surface temperatures across our southern TAF
sites will warm to near the freezing mark but in all probability,
should begin to cool off by a degree or two after the precip
begins.
Look for the light wintry mix to continue on and off tonight with a
transition over to light snow as the night wears on due to a cold
front pushing acrs the area and cooling temps off just enough in
the lower levels of the atmosphere for the changeover to occur.
Surface winds will remain out of the south today with speeds of 8
to 12 kts. As the cold front approaches this evening, winds will
start to veer more into a westerly direction. Once the front
passes across the area between 04z-08z, winds will become N-NW and
remain generally less than 10kt through 12z/6am Monday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 9 AM CST Monday FOR ILZ042>057-
061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Shimon
LONG TERM...HJS
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1154 AM EST SUN JAN 11 2015
.SYNOPSIS...
ISSUED AT 555 AM EST SUN JAN 11 2015
A COLD FRONT DROPPING SOUTHEAST ACROSS THE GREAT LAKES WILL
COMBINE WITH A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST FROM THE
SOUTHERN PLAINS TO CAUSE SNOW TO OVERSPREAD OUR AREA FROM SOUTH
TO NORTH THIS AFTERNOON. THE SNOW WILL CONTINUE ACROSS THE AREA
TONIGHT BEFORE TAPERING OFF FROM NORTHWEST TO SOUTHEAST MONDAY
MORNING. SNOW MAY BE MIXED WITH SLEET SOUTH OF ROUTE 24. NEW SNOW
ACCUMULATIONS ARE EXPECTED TO BE 2 TO 4 INCHES... WITH HEAVIEST
AMOUNTS ALONG A KNOX INDIANA TO DEFIANCE OHIO LINE. HIGHS TODAY WILL
BE IN THE UPPER 20S AND LOWER 30S... WITH LOWS TONIGHT IN THE MID
20S.
&&
.UPDATE...
ISSUED AT 1057 AM EST SUN JAN 11 2015
ISSUED A WINTER WX ADVISORY FOR COUNTIES SE OF THE HWY 24 CORRIDOR
IN OH/IN AS 12Z NAM AND LAST SEVERAL HRRR CYCLES HAVE TRENDED A
LITTLE WARMER/NORTH WITH WARM LAYER ALOFT (1-3C) THIS EVENING/EARLY
OVERNIGHT. AS A RESULT ADDED IN SOME LIGHT ICING AND CHANCES FOR
FREEZING RAIN DURING THIS TIME. THIS IN ADDITION TO 2-3" OF
SNOW/SLEET WARRANTS THE HEADLINE. OTHERWISE...NO SIGNIFICANT CHANGES
MADE TO THE FCST INTO THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM EST SUN JAN 11 2015
VIGOROUS SRN STREAM DISTURBANCE OVR CNTRL TX WILL LIFT OUT NEWD INTO
CONFLUENT FLW ACRS THE LAKES AND PHASE W/DOMINANT NRN STREAM SW
AMPLIFYING THROUGH SE CANADA. POTENT LL MSTR SURGE READILY OBSVD IN
00Z RAOBS ACRS TX/OK AND XPCD TO RACE NEWD INTO THE LAKES BY EARLY
AFTN. ISENTROPIC CHARTS IMPRESSIVE TO SAY THE LEAST W/DEEP 4+ G/KG
MIXR NOTED COMMENSURATE W/ESCALATING PRES ADVTN FM 21-09Z BFR
TAILING OFF...AND NO DOUBT TIED TO JET COUPLING ALOFT BOTH LT THIS
AFTN AND OVERNIGHT.
WHILE SHEARING NATURE OF SRN STREAM SW WILL DAMPEN BACKGROUND
FORCING...FGEN RESPONSE AND ASSOCD BANDED PCPN SEEN IN MOST
INDIVIDUAL 00Z MODEL SOLUTIONS MORE THAN ADEQUATELY HINT OF THE
POTENTIAL FOR ONE OR MORE OVER PERFORMING SNOW BANDS TO FORM BOTH
THIS AFTN AND AGAIN THIS EVENING...EITHER OF WHICH MAY YIELD
SUBSTANTIALLY MORE SNOW THAN CURRENTLY INDICATED IN GRIDS ESP
THROUGH CNTR OF CWA. PRIMARY PROBLEM THOUGH IS EXACT LOCATION W/EACH
SOLUTION VARIED ENOUGH TO DAMPEN OUT NEEDED RESOLUTION W/A BLENDED
CONSENSUS QPF SIGNAL. REGARDLESS...BUMPED PRECIP OVR ALL AREAS
HIGHER. CORRESPONDING SNOW AMTS ARE A TAD HIGHER AS WELL W/AN
EXCEPTION ACRS THE FAR SOUTH WHERE WARM NOSE INTRUSION WILL YIELD A
PD OF SLEET THIS EVENING. THERMAL PROFILES ARE LACKING W/SIG WAA
ONGOING NOW THROUGH THIS AFTN W/SHALLOW HIGH CNTRD DGZ NOTED IN BUFR
SNDGS. HWVR CONCERN EXISTS ESP IN LIGHT OF HIGHER TRENDING QPF
SIGNALS AMONG MOST MODEL GUIDANCE. WILL DEFER HEADLINES IF ANY TO
THE DAY SHIFT TO SORT OUT W/HOPEFULLY BETTER ALIGNED 12Z GUIDANCE.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM EST SUN JAN 11 2015
FLOW ALOFT TRENDING ZONAL ACROSS THE CONUS THIS WEEK SO A WARMUP IN
STORE... BUT WILL NEED TO ENDURE ONE MORE COLD SNAP BEFORE THEN AS A
SHALLOW ARCTIC AIRMASS MOVES INTO THE AREA BEHIND MONDAY`S CDFNT AND
THEN LINGERS THROUGH WED NGT AS HIGH PRESSURE MOVES SLOWLY SE FROM
THE NRN PLAINS ACROSS THE MIDWEST TUE-WED. WHILE TEMPS WILL BE WELL
BLO NORMAL IN THIS TIMEFRAME... WINDS WILL BE LIGHT SO COLD SHOULD
BE A LITTLE MORE TOLERABLE THAN PAST COUPLE OF COLD WAVES AND ATTM
DONT THINK ANY WIND CHILL HEADLINES WILL BE NEEDED THIS WEEK.
MAINTAINED GOING CATEGORICAL SNOW POPS ACROSS SE TAPERING TO LOW CHC
NW MONDAY MORNING AS FGEN FORCING ALONG H85 FRONT DROPS SE ACROSS
THE AREA WITH LINGERING MOIST AIRMASS IN PLACE. CONTD LOW SLR`S SE
WITH DEEP ISOTHERMAL NEAR FREEZING LAYER IN THIS AREA AND
HIGH/SHALLOW DGZ... FCST SNOW ACCUMS <1". DRY/SHALLOW ARCTIC AIRMASS
AND WINDS QUICKLY VEERING TO NNE MONDAY SUGGESTS LITTLE POTENTIAL
FOR POST-FRONTAL LAKE EFFECT... BUT DID MAINTAIN A LOW CHC IN THE
FAR NW IN THE AFTN. MODEST CAA SHOULD HOLD TEMPS NEARLY STEADY IN
THE 20S MONDAY... PLUMMETING TO AROUND ZERO MONDAY NIGHT AS SKIES
CLEAR AND WINDS DIMINISH. SHALLOW ARCTIC AIRMASS/WK LOW LEVEL MIXING
AS HIGH BUILDS INTO THE AREA TUE-WED SHOULD LIMIT DIURNAL TEMP RISES
WITH HIGHS ONLY 10-15 AND LOWS 0 TO -10. ZONAL FLOW ALOFT AND SW LOW
LEVEL FLOW LATE IN THE WEEK SHOULD RESULT IN A GOOD WARMUP WITH
TEMPS PRBLY A BIT ABOVE NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1153 AM EST SUN JAN 11 2015
VFR CLOUD DECK NEAR 5-6 KFT WILL CONTINUE TO LOWER THIS AFTERNOON
WITH SSW WINDS NEAR 10 KNOTS. CONDITIONS RAPIDLY DETERIORATE TO
IFR THIS EVENING AS SNOW AND DEEPER MOISTURE (POSSIBLY MIXED WITH
SLEET AT KFWA) OVERSPREADS THE REGION. OTHERWISE...LIGHT WINDS
TONIGHT WILL SHIFT NORTHWEST IN WAKE OF FRONTAL BOUNDARY MONDAY
MORNING WITH GRADUAL IMPROVEMENT IN CIGS/VIS ANTICIPATED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR INZ026-027-032>034.
MI...NONE.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
MONDAY FOR OHZ016-024-025.
LM...NONE.
&&
$$
UPDATE...STEINWEDEL
SYNOPSIS...JT
SHORT TERM...T
LONG TERM...JT
AVIATION...STEINWEDEL
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
134 PM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1216 PM MST SUN JAN 11 2015
ACROSS THE AREA AT 19Z...MOST AREAS IN THE 30S WITH SOME AREAS IN
THE WEST GETTING INTO L40S. INCREASE IN AREAL COVERAGE IN CLOUDS
EXPECTED THRU THE AFTERNOON WITH APPROACH OF FRONT. GOING FORECAST
HAS HANDLED WELL.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 400 AM MST SUN JAN 11 2015
TODAY-TONIGHT...LOOKS LIKE THE DAY WILL START OFF WITH SOME HIGH
CLOUDS GENERALLY NEAR THE KS/NE BORDER BUT AS THE DAY PROGRESSES MID
CLOUDS MOVE IN FROM THE NORTHWEST. LOW LEVELS OF THE ATMOSPHERE
REMAIN RATHER DRY SO NO PRECIPITATION EXPECTED. DURING THE OVERNIGHT
HOURS MODELS SUGGESTING A WEAK WEATHER DISTURBANCE PER 700-500MB
MOISTURE TO MOVE ALONG AND JUST SOUTH OF THE PALMER DIVIDE
BRINGING A SLIGHT CHANCE OF LIGHT SNOW TO PARTS OF FAR EASTERN
COLORADO...BEST CHANCE FOR CHEYENNE AND KIT CARSON COUNTIES. FOR
REMAINING AREAS GENERALLY ALONG/WEST OF THE CO/KS BORDER 850-700MB
MOISTURE SATURATES BUT MID LEVEL MOISTURE A BIT LACKING SO HAVE
KEPT SOME SMALL CHANCES FOR FLURRIES.
BIGGER CHALLENGE TODAY IS HIGH TEMPERATURES. MOST OF THE MODELS HAVE
BEEN WAY TOO COOL/COLD THE PAST SEVERAL DAYS EXCEPT FOR A FEW. HAVE
RELIED ON THOSE BETTER PERFORMING MODELS FOR THIS FORECAST AS TIMING
OF COLD FRONT AND ARRIVAL OF LEADING EDGE OF ARCTIC AIR WILL BE
CRITICAL. 18Z 850MB TEMPS SEVERAL DEGREES ABOVE 0F AND THROUGH 21Z
STILL ABOVE ZERO FOR ALL BUT THE NORTHERN EDGE OF YUMA COUNTY. BY
00Z THE COLD PUSH REACHES INTERSTATE 70. AFTER SEEING THE 9Z RUC AND
LATEST HRRR (WHICH DID RATHER WELL WITH SATURDAYS TEMPERATURES) HAVE
FINALIZED HIGHS IN THE MID/UPPER 30S ALONG/NORTH OF THE KS/NE BORDER
WITH 40S TO THE SOUTH. HAVE AROUND 50 IN THE TRIBUNE AREA. 1040MB
SFC HIGH REACHES THE AREA TONIGHT LOWS TONIGHT 5-10F ACROSS THE
NORTHEAST 1/2 OF THE AREA WITH 10-15F TO THE SOUTHWEST.
MONDAY-MONDAY NIGHT...1043MB SFC HIGH NOSING INTO THE AREA DURING
THE MORNING THEN WEAKENING JUST A BIT. SHOULD SEE SOME LINGERING
LIGHT SNOW ACROSS MOST OF FAR EASTERN COLORADO IN THE MORNING BEFORE
MID LEVEL MOISTURE MOVES AWAY LEAVING THE AREA UNDER PLENTY OF
CLOUDS. FOR THE OVERNIGHT HOURS WE ARE IN BETWEEN DEPARTING SYSTEM
AND APPROACHING UPPER TROUGH AND NEXT BATCH OF MOISTURE WITH SHORT
WAVE RIDGING OVER THE AREA. MID LEVEL MOISTURE LACKING FOR ANY
PRECIP SO JUST MOSTLY CLOUDY/CLOUDY CONDITIONS EXPECTED. HIGH
TEMPERATURES ONLY IN THE MID TEENS TO LOW 20S (NORTHEAST TO
SOUTHWEST ORIENTATION ACROSS THE AREA) WITH OVERNIGHT LOWS GENERALLY
5F-13F.
TUESDAY-TUESDAY NIGHT...AROUND SUNRISE BASE OF UPPER TROUGH EXPECTED
OVER SALT LAKE CITY AREA CLOSING OFF WHILE MOVING SOUTHEAST TOWARD
NORTHWEST NEW MEXICO/FOUR CORNERS AREA. DURING THE OVERNIGHT HOURS
WEAKEN THE LOW A BIT WHILE ALSO PUSHING IT EAST/SOUTHEAST.
FORECAST ISSUE FOR THE PERIOD IS TIMING AND PLACEMENT OF
PRECIPITATION CHANCES. MODELS IN GENERAL AGREE ON BRINGING
INCREASING MOISTURE TO THE AREA FROM THE WEST/SOUTHWEST DURING THE
DAY WITH A BIT OF DIFFERING SOLUTIONS AS TO WHETHER OR NOT SOME
DRIER AIR MOVES IN FROM THE NORTHWEST. NAM SAYS NO WHILE GFS/ECMWF
SAY YES. SO FOR NOW VERY LITTLE CHANGE MADE TO FORECAST. GFS/ECWMF
IN BETTER AGREEMENT BRINGING DRIER IN FROM THE NORTHWEST DURING THE
NIGHT WHICH IS SIMILAR TO LAST NIGHTS SOLUTIONS. SO FOR NOW...NO
CHANGES MADE.
TEMPERATURES WILL CONTINUE TO BE COLD WITH HIGH TEMPERATURES IN THE
LOW TO MID 20S AND LOWS GENERALLY 10-15F...COLDEST AROUND MCCOOK
WITH HIGHEST VALUES FROM FLAGLER TO LEOTI.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 211 AM MST SUN JAN 11 2015
FORECAST CHALLENGES ARE RESOLVING THE WARMING TEMPERATURES AND
PERSISTENT WEST TO EAST/WARM TO COOL GRADIENT ACROSS THE FORECAST
AREA.
THE UPPER TROUGH THAT MOVED THROUGH THE CENTRAL HIGH PLAINS REGION
LATE TUESDAY AND TUESDAY NIGHT MOVES OUT OF THE REGION WEDNESDAY.
NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY NIGHT AND THURSDAY AS THE
UPPER RIDGE MOVES OVER THE ROCKIES AND HIGH PLAINS. COLD AIR AT THE
SURFACE IS SWEPT OUT OF THE CENTRAL HIGH PLAINS AS THE HIGH PRESSURE
AREA MOVES EAST AND A LEE TROUGH DEEPENS NEAR THE EASTERN COLORADO
BORDER.
DIFFERENCES ARE SHOWING UP BETWEEN THE GFS AND ECMWF OVER THE
CENTRAL HIGH PLAINS REGION THURSDAY NIGHT AND FRIDAY. THE ECMWF IS
PRODUCING TWO SEPARATE WEAKER SHORT WAVE TROUGHS THAT MOVE ACROSS
THE FORECAST AREA WHILE THE GFS IS PRODUCING A STRONGER CLOSED LOW
CENTER THAT FITS INTO THE TIMING OF THE SECOND OPEN WAVE
IDENTIFIED BY THE ECMWF FRIDAY AFTERNOON AND EVENING. MAY END UP
JUST SEEING AN INCREASE IN HIGH CLOUDS ASSOCIATED WITH THE WAVE ON
FRIDAY...BUT EXTENDED BLEND MAY BE TOO DRY AS IT HAS VERY LITTLE
CLOUD COVER IN FORECAST BEYOND WEDNESDAY WITH OVERALL DRY
CONDITIONS AND TEMPERATURES WARMING THROUGH THE END OF THE WEEK
WITH RIDGING ALOFT EXPECTED ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 400 AM MST SUN JAN 11 2015
KGLD...VFR CONDITIONS THROUGH 22Z WITH WINDS VARIABLE AT 5KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH A GRADUAL
INCREASE IN CLOUDS STARTING MID TO LATE MORNING. AROUND 23Z
STRATUS STARTS TO APPROACH THE TERMINAL AS WINDS BECOME NORTHERLY
AROUND 10KTS. ITS EXPECTED THAT FROM 00Z THROUGH 11Z STRATUS WILL
COVER THE TERMINAL WITH VLIFR CIGS. SHORTLY AFTER 11Z STRATUS
CONCENTRATION SHIFTS TO THE WEST POSSIBLY ALLOWING VFR CONDITIONS
TO RETURN WITH NORTHEAST WINDS AROUND 10KTS. SOME SNOW FLURRIES
ARE POSSIBLE AT THE TAIL END OF THE PERIOD.
KMCK...VFR CONDITIONS THROUGH 20Z WITH WINDS VARIABLE AT 3KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH AN INCREASE IN
MID AND HIGH CLOUDS MID TO LATE MORNING. AROUND 21Z STRATUS
APPROACHES THE TERMINAL FROM THE NORTH WITH WINDS SHIFTING TO THE
NORTHEAST AROUND 5KTS. BY 23Z IF NOT AN HOUR OR POSSIBLY TWO
EARLIER VLIFR CIGS EXPECTED WITH NORTH WINDS AROUND 10KTS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z-07Z BEFORE
RETURNING TO VFR AS THE SATURATED LOW LEVEL AIRMASS MOVES
WEST/SOUTHWEST OF THE TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 133 PM MST SUN JAN 11 2015
ICE JAM CONCERNS WILL PERSIST OVER THE NEXT SEVERAL DAYS ON
THE REPUBLICAN RIVER NEAR DOANE RD 333...SOUTH AND WEST OF
BENKELMAN. WITH MOST OF THE UPCOMING WEEK HAVING HIGH TEMPS NEAR TO
ABOVE FREEZING...AND OVERNIGHT LOWS DROPPING INTO THE TEENS AND EVEN
SINGLE NUMBERS ABOVE ZERO EARLY ON...THE RIVER IN THAT AREA WILL SEE
FREEZING AT NIGHT WITH MELTING OF ICE DURING THE DAY. RISES IN THE
GRAPH GAGE OF BENN1 DO REFLECT THIS ALTHOUGH A DECREASING TREND HAS
BEEN SEEN OVER PAST FEW DAYS. ALTHOUGH THIS GAGE IS A FEW MILES
DOWNSTREAM FROM THE TROUBLE SITE...TREND DOES REFLECT. OVERALL SITE
WILL HAVE TO CONTINUE TO BE MONITORED DURING THIS TIME. THE ONLY
HELP THIS AREA WILL SEE IS THAT THE WARMING TREND BY THE END OF THE
WEEK MAY DO ENOUGH MELTING DURING THE DAY ON THE RIVER ICE TO
ALLEVIATE CONDITIONS TO REDUCE MINOR FLOODING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...99
LONG TERM...LOCKHART
AVIATION...99
HYDROLOGY...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1216 PM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1216 PM MST SUN JAN 11 2015
ACROSS THE AREA AT 19Z...MOST AREAS IN THE 30S WITH SOME AREAS IN
THE WEST GETTING INTO L40S. INCREASE IN AREAL COVERAGE IN CLOUDS
EXPECTED THRU THE AFTERNOON WITH APPROACH OF FRONT. GOING FORECAST
HAS HANDLED WELL.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 400 AM MST SUN JAN 11 2015
TODAY-TONIGHT...LOOKS LIKE THE DAY WILL START OFF WITH SOME HIGH
CLOUDS GENERALLY NEAR THE KS/NE BORDER BUT AS THE DAY PROGRESSES MID
CLOUDS MOVE IN FROM THE NORTHWEST. LOW LEVELS OF THE ATMOSPHERE
REMAIN RATHER DRY SO NO PRECIPITATION EXPECTED. DURING THE OVERNIGHT
HOURS MODELS SUGGESTING A WEAK WEATHER DISTURBANCE PER 700-500MB
MOISTURE TO MOVE ALONG AND JUST SOUTH OF THE PALMER DIVIDE
BRINGING A SLIGHT CHANCE OF LIGHT SNOW TO PARTS OF FAR EASTERN
COLORADO...BEST CHANCE FOR CHEYENNE AND KIT CARSON COUNTIES. FOR
REMAINING AREAS GENERALLY ALONG/WEST OF THE CO/KS BORDER 850-700MB
MOISTURE SATURATES BUT MID LEVEL MOISTURE A BIT LACKING SO HAVE
KEPT SOME SMALL CHANCES FOR FLURRIES.
BIGGER CHALLENGE TODAY IS HIGH TEMPERATURES. MOST OF THE MODELS HAVE
BEEN WAY TOO COOL/COLD THE PAST SEVERAL DAYS EXCEPT FOR A FEW. HAVE
RELIED ON THOSE BETTER PERFORMING MODELS FOR THIS FORECAST AS TIMING
OF COLD FRONT AND ARRIVAL OF LEADING EDGE OF ARCTIC AIR WILL BE
CRITICAL. 18Z 850MB TEMPS SEVERAL DEGREES ABOVE 0F AND THROUGH 21Z
STILL ABOVE ZERO FOR ALL BUT THE NORTHERN EDGE OF YUMA COUNTY. BY
00Z THE COLD PUSH REACHES INTERSTATE 70. AFTER SEEING THE 9Z RUC AND
LATEST HRRR (WHICH DID RATHER WELL WITH SATURDAYS TEMPERATURES) HAVE
FINALIZED HIGHS IN THE MID/UPPER 30S ALONG/NORTH OF THE KS/NE BORDER
WITH 40S TO THE SOUTH. HAVE AROUND 50 IN THE TRIBUNE AREA. 1040MB
SFC HIGH REACHES THE AREA TONIGHT LOWS TONIGHT 5-10F ACROSS THE
NORTHEAST 1/2 OF THE AREA WITH 10-15F TO THE SOUTHWEST.
MONDAY-MONDAY NIGHT...1043MB SFC HIGH NOSING INTO THE AREA DURING
THE MORNING THEN WEAKENING JUST A BIT. SHOULD SEE SOME LINGERING
LIGHT SNOW ACROSS MOST OF FAR EASTERN COLORADO IN THE MORNING BEFORE
MID LEVEL MOISTURE MOVES AWAY LEAVING THE AREA UNDER PLENTY OF
CLOUDS. FOR THE OVERNIGHT HOURS WE ARE IN BETWEEN DEPARTING SYSTEM
AND APPROACHING UPPER TROUGH AND NEXT BATCH OF MOISTURE WITH SHORT
WAVE RIDGING OVER THE AREA. MID LEVEL MOISTURE LACKING FOR ANY
PRECIP SO JUST MOSTLY CLOUDY/CLOUDY CONDITIONS EXPECTED. HIGH
TEMPERATURES ONLY IN THE MID TEENS TO LOW 20S (NORTHEAST TO
SOUTHWEST ORIENTATION ACROSS THE AREA) WITH OVERNIGHT LOWS GENERALLY
5F-13F.
TUESDAY-TUESDAY NIGHT...AROUND SUNRISE BASE OF UPPER TROUGH EXPECTED
OVER SALT LAKE CITY AREA CLOSING OFF WHILE MOVING SOUTHEAST TOWARD
NORTHWEST NEW MEXICO/FOUR CORNERS AREA. DURING THE OVERNIGHT HOURS
WEAKEN THE LOW A BIT WHILE ALSO PUSHING IT EAST/SOUTHEAST.
FORECAST ISSUE FOR THE PERIOD IS TIMING AND PLACEMENT OF
PRECIPITATION CHANCES. MODELS IN GENERAL AGREE ON BRINGING
INCREASING MOISTURE TO THE AREA FROM THE WEST/SOUTHWEST DURING THE
DAY WITH A BIT OF DIFFERING SOLUTIONS AS TO WHETHER OR NOT SOME
DRIER AIR MOVES IN FROM THE NORTHWEST. NAM SAYS NO WHILE GFS/ECMWF
SAY YES. SO FOR NOW VERY LITTLE CHANGE MADE TO FORECAST. GFS/ECWMF
IN BETTER AGREEMENT BRINGING DRIER IN FROM THE NORTHWEST DURING THE
NIGHT WHICH IS SIMILAR TO LAST NIGHTS SOLUTIONS. SO FOR NOW...NO
CHANGES MADE.
TEMPERATURES WILL CONTINUE TO BE COLD WITH HIGH TEMPERATURES IN THE
LOW TO MID 20S AND LOWS GENERALLY 10-15F...COLDEST AROUND MCCOOK
WITH HIGHEST VALUES FROM FLAGLER TO LEOTI.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 211 AM MST SUN JAN 11 2015
FORECAST CHALLENGES ARE RESOLVING THE WARMING TEMPERATURES AND
PERSISTENT WEST TO EAST/WARM TO COOL GRADIENT ACROSS THE FORECAST
AREA.
THE UPPER TROUGH THAT MOVED THROUGH THE CENTRAL HIGH PLAINS REGION
LATE TUESDAY AND TUESDAY NIGHT MOVES OUT OF THE REGION WEDNESDAY.
NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY NIGHT AND THURSDAY AS THE
UPPER RIDGE MOVES OVER THE ROCKIES AND HIGH PLAINS. COLD AIR AT THE
SURFACE IS SWEPT OUT OF THE CENTRAL HIGH PLAINS AS THE HIGH PRESSURE
AREA MOVES EAST AND A LEE TROUGH DEEPENS NEAR THE EASTERN COLORADO
BORDER.
DIFFERENCES ARE SHOWING UP BETWEEN THE GFS AND ECMWF OVER THE
CENTRAL HIGH PLAINS REGION THURSDAY NIGHT AND FRIDAY. THE ECMWF IS
PRODUCING TWO SEPARATE WEAKER SHORT WAVE TROUGHS THAT MOVE ACROSS
THE FORECAST AREA WHILE THE GFS IS PRODUCING A STRONGER CLOSED LOW
CENTER THAT FITS INTO THE TIMING OF THE SECOND OPEN WAVE
IDENTIFIED BY THE ECMWF FRIDAY AFTERNOON AND EVENING. MAY END UP
JUST SEEING AN INCREASE IN HIGH CLOUDS ASSOCIATED WITH THE WAVE ON
FRIDAY...BUT EXTENDED BLEND MAY BE TOO DRY AS IT HAS VERY LITTLE
CLOUD COVER IN FORECAST BEYOND WEDNESDAY WITH OVERALL DRY
CONDITIONS AND TEMPERATURES WARMING THROUGH THE END OF THE WEEK
WITH RIDGING ALOFT EXPECTED ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 400 AM MST SUN JAN 11 2015
KGLD...VFR CONDITIONS THROUGH 22Z WITH WINDS VARIABLE AT 5KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH A GRADUAL
INCREASE IN CLOUDS STARTING MID TO LATE MORNING. AROUND 23Z
STRATUS STARTS TO APPROACH THE TERMINAL AS WINDS BECOME NORTHERLY
AROUND 10KTS. ITS EXPECTED THAT FROM 00Z THROUGH 11Z STRATUS WILL
COVER THE TERMINAL WITH VLIFR CIGS. SHORTLY AFTER 11Z STRATUS
CONCENTRATION SHIFTS TO THE WEST POSSIBLY ALLOWING VFR CONDITIONS
TO RETURN WITH NORTHEAST WINDS AROUND 10KTS. SOME SNOW FLURRIES
ARE POSSIBLE AT THE TAIL END OF THE PERIOD.
KMCK...VFR CONDITIONS THROUGH 20Z WITH WINDS VARIABLE AT 3KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH AN INCREASE IN
MID AND HIGH CLOUDS MID TO LATE MORNING. AROUND 21Z STRATUS
APPROACHES THE TERMINAL FROM THE NORTH WITH WINDS SHIFTING TO THE
NORTHEAST AROUND 5KTS. BY 23Z IF NOT AN HOUR OR POSSIBLY TWO
EARLIER VLIFR CIGS EXPECTED WITH NORTH WINDS AROUND 10KTS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z-07Z BEFORE
RETURNING TO VFR AS THE SATURATED LOW LEVEL AIRMASS MOVES
WEST/SOUTHWEST OF THE TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 916 AM MST SUN JAN 11 2015
FLSGLD HAS BEEN RE-ISSUED FOR THE NEXT 12 HOURS TO ACCOMMODATE
MINOR ICE JAM FLOODING NEAR DOANE RD 333...5SM WEST OF BENKELMAN.
LATEST CALL TO COUNTY DISPATCH HAS GIVEN US A NO CHANGE IN
CONDITIONS AT THIS TIME. WILL CONTINUE TO MONITOR THRU THE DAY. A
COMBINATION OF FREEZING TEMPS AT NIGHT..WITH THE ADDITION OF
WATER LET LOOSE FROM DAM UPSTREAM COULD ALLOW CONDITIONS TO
CONTINUE FOR NEXT SEVERAL DAYS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...99
LONG TERM...LOCKHART
AVIATION...99
HYDROLOGY...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
916 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 910 AM MST SUN JAN 11 2015
UPDATE ISSUED TO MAKE MINOR CHANGES IN TEMPS BASED OFF OF LATEST
HOURLIES...OTHERWISE FORECAST IN GOOD SHAPE AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 400 AM MST SUN JAN 11 2015
TODAY-TONIGHT...LOOKS LIKE THE DAY WILL START OFF WITH SOME HIGH
CLOUDS GENERALLY NEAR THE KS/NE BORDER BUT AS THE DAY PROGRESSES MID
CLOUDS MOVE IN FROM THE NORTHWEST. LOW LEVELS OF THE ATMOSPHERE
REMAIN RATHER DRY SO NO PRECIPITATION EXPECTED. DURING THE OVERNIGHT
HOURS MODELS SUGGESTING A WEAK WEATHER DISTURBANCE PER 700-500MB
MOISTURE TO MOVE ALONG AND JUST SOUTH OF THE PALMER DIVIDE
BRINGING A SLIGHT CHANCE OF LIGHT SNOW TO PARTS OF FAR EASTERN
COLORADO...BEST CHANCE FOR CHEYENNE AND KIT CARSON COUNTIES. FOR
REMAINING AREAS GENERALLY ALONG/WEST OF THE CO/KS BORDER 850-700MB
MOISTURE SATURATES BUT MID LEVEL MOISTURE A BIT LACKING SO HAVE
KEPT SOME SMALL CHANCES FOR FLURRIES.
BIGGER CHALLENGE TODAY IS HIGH TEMPERATURES. MOST OF THE MODELS HAVE
BEEN WAY TOO COOL/COLD THE PAST SEVERAL DAYS EXCEPT FOR A FEW. HAVE
RELIED ON THOSE BETTER PERFORMING MODELS FOR THIS FORECAST AS TIMING
OF COLD FRONT AND ARRIVAL OF LEADING EDGE OF ARCTIC AIR WILL BE
CRITICAL. 18Z 850MB TEMPS SEVERAL DEGREES ABOVE 0F AND THROUGH 21Z
STILL ABOVE ZERO FOR ALL BUT THE NORTHERN EDGE OF YUMA COUNTY. BY
00Z THE COLD PUSH REACHES INTERSTATE 70. AFTER SEEING THE 9Z RUC AND
LATEST HRRR (WHICH DID RATHER WELL WITH SATURDAYS TEMPERATURES) HAVE
FINALIZED HIGHS IN THE MID/UPPER 30S ALONG/NORTH OF THE KS/NE BORDER
WITH 40S TO THE SOUTH. HAVE AROUND 50 IN THE TRIBUNE AREA. 1040MB
SFC HIGH REACHES THE AREA TONIGHT LOWS TONIGHT 5-10F ACROSS THE
NORTHEAST 1/2 OF THE AREA WITH 10-15F TO THE SOUTHWEST.
MONDAY-MONDAY NIGHT...1043MB SFC HIGH NOSING INTO THE AREA DURING
THE MORNING THEN WEAKENING JUST A BIT. SHOULD SEE SOME LINGERING
LIGHT SNOW ACROSS MOST OF FAR EASTERN COLORADO IN THE MORNING BEFORE
MID LEVEL MOISTURE MOVES AWAY LEAVING THE AREA UNDER PLENTY OF
CLOUDS. FOR THE OVERNIGHT HOURS WE ARE IN BETWEEN DEPARTING SYSTEM
AND APPROACHING UPPER TROUGH AND NEXT BATCH OF MOISTURE WITH SHORT
WAVE RIDGING OVER THE AREA. MID LEVEL MOISTURE LACKING FOR ANY
PRECIP SO JUST MOSTLY CLOUDY/CLOUDY CONDITIONS EXPECTED. HIGH
TEMPERATURES ONLY IN THE MID TEENS TO LOW 20S (NORTHEAST TO
SOUTHWEST ORIENTATION ACROSS THE AREA) WITH OVERNIGHT LOWS GENERALLY
5F-13F.
TUESDAY-TUESDAY NIGHT...AROUND SUNRISE BASE OF UPPER TROUGH EXPECTED
OVER SALT LAKE CITY AREA CLOSING OFF WHILE MOVING SOUTHEAST TOWARD
NORTHWEST NEW MEXICO/FOUR CORNERS AREA. DURING THE OVERNIGHT HOURS
WEAKEN THE LOW A BIT WHILE ALSO PUSHING IT EAST/SOUTHEAST.
FORECAST ISSUE FOR THE PERIOD IS TIMING AND PLACEMENT OF
PRECIPITATION CHANCES. MODELS IN GENERAL AGREE ON BRINGING
INCREASING MOISTURE TO THE AREA FROM THE WEST/SOUTHWEST DURING THE
DAY WITH A BIT OF DIFFERING SOLUTIONS AS TO WHETHER OR NOT SOME
DRIER AIR MOVES IN FROM THE NORTHWEST. NAM SAYS NO WHILE GFS/ECMWF
SAY YES. SO FOR NOW VERY LITTLE CHANGE MADE TO FORECAST. GFS/ECWMF
IN BETTER AGREEMENT BRINGING DRIER IN FROM THE NORTHWEST DURING THE
NIGHT WHICH IS SIMILAR TO LAST NIGHTS SOLUTIONS. SO FOR NOW...NO
CHANGES MADE.
TEMPERATURES WILL CONTINUE TO BE COLD WITH HIGH TEMPERATURES IN THE
LOW TO MID 20S AND LOWS GENERALLY 10-15F...COLDEST AROUND MCCOOK
WITH HIGHEST VALUES FROM FLAGLER TO LEOTI.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 211 AM MST SUN JAN 11 2015
FORECAST CHALLENGES ARE RESOLVING THE WARMING TEMPERATURES AND
PERSISTENT WEST TO EAST/WARM TO COOL GRADIENT ACROSS THE FORECAST
AREA.
THE UPPER TROUGH THAT MOVED THROUGH THE CENTRAL HIGH PLAINS REGION
LATE TUESDAY AND TUESDAY NIGHT MOVES OUT OF THE REGION WEDNESDAY.
NORTHWEST FLOW WILL BE IN PLACE WEDNESDAY NIGHT AND THURSDAY AS THE
UPPER RIDGE MOVES OVER THE ROCKIES AND HIGH PLAINS. COLD AIR AT THE
SURFACE IS SWEPT OUT OF THE CENTRAL HIGH PLAINS AS THE HIGH PRESSURE
AREA MOVES EAST AND A LEE TROUGH DEEPENS NEAR THE EASTERN COLORADO
BORDER.
DIFFERENCES ARE SHOWING UP BETWEEN THE GFS AND ECMWF OVER THE
CENTRAL HIGH PLAINS REGION THURSDAY NIGHT AND FRIDAY. THE ECMWF IS
PRODUCING TWO SEPARATE WEAKER SHORT WAVE TROUGHS THAT MOVE ACROSS
THE FORECAST AREA WHILE THE GFS IS PRODUCING A STRONGER CLOSED LOW
CENTER THAT FITS INTO THE TIMING OF THE SECOND OPEN WAVE
IDENTIFIED BY THE ECMWF FRIDAY AFTERNOON AND EVENING. MAY END UP
JUST SEEING AN INCREASE IN HIGH CLOUDS ASSOCIATED WITH THE WAVE ON
FRIDAY...BUT EXTENDED BLEND MAY BE TOO DRY AS IT HAS VERY LITTLE
CLOUD COVER IN FORECAST BEYOND WEDNESDAY WITH OVERALL DRY
CONDITIONS AND TEMPERATURES WARMING THROUGH THE END OF THE WEEK
WITH RIDGING ALOFT EXPECTED ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 400 AM MST SUN JAN 11 2015
KGLD...VFR CONDITIONS THROUGH 22Z WITH WINDS VARIABLE AT 5KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH A GRADUAL
INCREASE IN CLOUDS STARTING MID TO LATE MORNING. AROUND 23Z
STRATUS STARTS TO APPROACH THE TERMINAL AS WINDS BECOME NORTHERLY
AROUND 10KTS. ITS EXPECTED THAT FROM 00Z THROUGH 11Z STRATUS WILL
COVER THE TERMINAL WITH VLIFR CIGS. SHORTLY AFTER 11Z STRATUS
CONCENTRATION SHIFTS TO THE WEST POSSIBLY ALLOWING VFR CONDITIONS
TO RETURN WITH NORTHEAST WINDS AROUND 10KTS. SOME SNOW FLURRIES
ARE POSSIBLE AT THE TAIL END OF THE PERIOD.
KMCK...VFR CONDITIONS THROUGH 20Z WITH WINDS VARIABLE AT 3KTS OR
LESS. SKC CONDITIONS TO START THE TAF PERIOD WITH AN INCREASE IN
MID AND HIGH CLOUDS MID TO LATE MORNING. AROUND 21Z STRATUS
APPROACHES THE TERMINAL FROM THE NORTH WITH WINDS SHIFTING TO THE
NORTHEAST AROUND 5KTS. BY 23Z IF NOT AN HOUR OR POSSIBLY TWO
EARLIER VLIFR CIGS EXPECTED WITH NORTH WINDS AROUND 10KTS. THESE
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 06Z-07Z BEFORE
RETURNING TO VFR AS THE SATURATED LOW LEVEL AIRMASS MOVES
WEST/SOUTHWEST OF THE TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 916 AM MST SUN JAN 11 2015
FLSGLD HAS BEEN RE-ISSUED FOR THE NEXT 12 HOURS TO ACCOMMODATE
MINOR ICE JAM FLOODING NEAR DOANE RD 333...5SM WEST OF BENKELMAN.
LATEST CALL TO COUNTY DISPATCH HAS GIVEN US A NO CHANGE IN
CONDITIONS AT THIS TIME. WILL CONTINUE TO MONITOR THRU THE DAY. A
COMBINATION OF FREEZING TEMPS AT NIGHT..WITH THE ADDITION OF
WATER LET LOOSE FROM DAM UPSTREAM COULD ALLOW CONDITIONS TO
CONTINUE FOR NEXT SEVERAL DAYS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...99
LONG TERM...LOCKHART
AVIATION...99
HYDROLOGY...JN
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
334 PM EST SUN JAN 11 2015
.SYNOPSIS...
ARCTIC HIGH PRESSURE WILL SHIFT OFF THE EAST COAST TONIGHT. A WEAK COLD
FRONT WILL CROSS THE AREA ON MONDAY. HIGH PRESSURE WILL BUILD NORTH
THROUGH MIDWEEK BEFORE LOW PRESSURE MOVES OFF THE CAROLINA COAST
THURSDAY NIGHT. HIGH PRESSURE THEN PREVAILS INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH MONDAY/...
CLOUDS CONTINUE TO INCREASE THIS AFTERNOON AND EVENING AHEAD OF
APPROACHING SOUTHERN STREAM STORM SYSTEM. TEMPERATURES ABOVE
FREEZING IN MOST LOCATIONS AND MAY BE SLOW TO FALL EARLY THIS
EVENING.
THE PRIMARY CONCERN OF THE SHORT TERM FORECAST IS THE POTENTIAL FOR
A LIGHT ICING EVENT ACROSS MOST IF NOT THE ENTIRE AREA LATE TONIGHT
AND EARLY MONDAY MORNING. THE ONE CRITICAL ELEMENT OF THE FORECAST
WILL BE THE SFC TEMPERATURES. NOT MUCH CHANGE IN THE THERMAL PROFILE
ALOFT...AS A WARM NOSE GREATER THAN 3C WILL BE IN PLACE ACROSS MOST
OF THE AREA BY THE TIME PRECIP STARTS. SOME SLEET MAY MIX IN AT THE
ONSET ACROSS THE NORTHERN THIRD OF THE AREA BUT THIS SHOULD BE SHORT
LIVED. ADMITTEDLY IT IS DISCONCERTING TO SEE THE SPREAD IN SFC TEMPS
AND THE MODELS TRYING TO HANG ON TO ABOVE FREEZING AIR. THIS IS NOT
TOTALLY UNEXPECTED SINCE THE SFC HIGH OFF THE COAST WILL NOT SUPPORT
A CLASSIC CAD AND THERE WILL NOT BE COLD AIR REPLENISHMENT FROM THE
NORTHEAST. WE WILL HAVE TO RELY ON AN IN-SITU CAD EVENT/WET BULB
PROCESSES TO TAKE PLACE...AND THIS DOES SUPPORT TEMPS FALLING BELOW
FREEZING ACROSS MOST OF THE AREA FOR AT LEAST SEVERAL HOURS
OVERNIGHT. THE FIRST PLACES TO RISE ABOVE FREEZING (ASSUMING THEY
FALL BELOW) WILL BE THE HIGHER ELEVATIONS (THE WARM NOSE WILL WORK
DOWN TO THEM FIRST) AND THE COASTAL PLAIN (THE SOUTHERLY FLOW WILL
PREVENT TEMPERATURES FROM STAYING COLD). IN ADDITION TO A COLDER
START FROM THIS AFTERNOON...THE PRECIP-INDUCED COOLING WILL HAVE A
HARDER TIME SCOURING OUT OF NORTHERN MD...THE EASTERN WV
PANHANDLE...AND PERHAPS FAR NORTHERN VA. IN THIS AREA WE HAVE THE
HIGHEST CONFIDENCE OF ACCUMULATING ICE.
PRECIP START TIME IS SHOWING SOME VARIATION IN THE MODELS...WITH
RECENT HRRR AND RAP RUNS WELL AFTER MIDNIGHT. DIDN/T MAKE MUCH
CHANGE TO THE GOING FORECAST POPS AS THE MAJORITY OF THE MODELS
STILL WARRANT POPS INCREASING JUST PRIOR TO MIDNIGHT. HOWEVER
WIDESPREAD PRECIP MAY NOT START UNTIL AFTER 09Z.
ICE ACCUMULATIONS SHOULD BE LIGHT GIVEN THE TEMPERATURES NEAR
FREEZING BUT AS NOTED ABOVE...THE HIGHEST AMOUNTS ARE EXPECTED
CLOSER TO THE MD/PA BORDER. HAVE CAPPED THESE AROUND 0.1 INCH...BUT
A FEW HIGHER REPORTS ARE POSSIBLE. OTHER AREAS WILL PROBABLY BE
LESS...BUT TEMPS/PRECIP RATES WILL HAVE TO BE MONITORED. ANOTHER
ISSUE TO CONSIDER IS THE AMBIENT COLD GROUND AFTER THE RECENT COLD
SPELL. COULD SEE ACCRETION OCCUR EVEN WITH AIR TEMPS SLIGHTLY ABOVE
FREEZING. TYPICALLY SHADED SPOTS AND BRIDGES WOULD BE A GREATER
CONCERN FOR THE GROUND ACCUMULATIONS. IMPORTANTLY...FZRA WILL LIKELY
BE AFFECTING MUCH OF THE AREA DURING THE MORNING COMMUTE. THEREFORE
HAVE ISSUED A FREEZING RAIN ADVISORY FOR THE ENTIRE AREA. IT WILL
RUN THROUGH 9 AM FOR MOST OF THE AREA EXCEPT THE COLDER LOCATIONS
MENTIONED ABOVE WHERE IT WILL BE IN EFFECT UNTIL 1 PM. THESE TIMES
MAY BE A LITTLE LENGTHY FOR SOME LOCATIONS...BUT WANTED TO
INCORPORATE UNCERTAINTY AND UNEVEN DISTRIBUTION OF THE TEMPERATURE
CURVE.
THE PRECIP WILL BE ALL RAIN DURING THE AFTERNOON AND BEGIN TO TAPER
OFF FROM WEST TO EAST. A STRONGER LLJ WILL MEAN PLENTY OF FORCING
AND MOISTURE FOR A GENERALLY STEADY RAIN...IN ADDITION TO HELPING
ELIMINATE ANY INVERSION AND THE TEMPERATURES RISE. MID 40S WILL BE
POSSIBLE IN THE SOUTHERN PART OF THE AREA...WITH THE NORTH STUCK IN
THE MID 30S.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
ANOTHER SURGE OF ARCTIC AIR WILL POUR INTO THE MIDDLE ATLANTIC
REGION MONDAY NIGHT. TEMPERATURES WILL DROP INTO THE TEENS IN MOST
AREAS WITH LOWER 20S IN THE BALTIMORE AND WASHINGTON DC METRO.
COLD HIGH PRESSURE WILL BUILD IN FOR TUESDAY AND TEMPERATURES WILL
NOT RISE ALL THAT MUCH DESPITE SUNSHINE. HIGH TEMPERATURES WILL ONLY
REACH THE MIDDLE TO UPPER 20S IN MOST LOCATIONS...PERHAPS LOW 30S
OVER SOUTHERN PORTIONS OF THE AREA. DRIER AIR WILL ALSO FILSTER IN
WITH THE HIGH PRESSURE RIDGE. HAVE REMOVED POPS FOR ALL AREAS
DURING THE DAY. ANOTHER COLD NIGHT EXPECTED TUESDAY NIGHT WITH
LOWS IN THE TEENS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE LONG TERM WILL BEGIN WITH THE MID-ATLANTIC IN A WEAK CAD
SITUATION DUE TO ELONGATED TROUGHING TO OUR NORTH...STRETCHING FROM
THE GREAT LAKES TO NEW ENGLAND...AND A BROAD AREA OF TROUGHING
LOCATED ALONG AND OFF THE SOUTHEAST COAST TO OUR SOUTH. WHILE MOST
OF THE PRECIPITATION ASSOCIATED WITH THE TROUGHING SHOULD STAY TO
OUR SOUTH THROUGH MIDWEEK...A WEAK SHORTWAVE CROSSING THE AREA DURING THE
DAYTIME WEDNESDAY WILL PROVIDE THE BEST CHANCE FOR PRECIP TO REACH
THE CWA. THUS CHANCE POPS MAINLY CONFINED TO THE SOUTHEASTERN SECTOR
OF THE CWA WEDNESDAY THROUGH THURSDAY. COLD AIR IN PLACE AT THE
SURFACE AND LACK OF STRONG WARM NOSE IN THE MID-LEVELS SHOULD ENSURE
THAT ANY PRECIP THAT DOES FALL WILL BE IN THE FORM OF SNOW...WITH
THE EXCEPTION OF THE FAR SOUTHERN PORTION OF THE CWA WHERE TEMPS
SHOULD BE WARM ENOUGH DURING THE DAYTIME THURSDAY TO PRODUCE PLAIN
RAIN. POPS CURRENTLY TOO LOW TO EXPECT ANY ACCUMULATION.
BROAD HIGH PRESSURE WILL BEGIN TO BUILD IN WEDNESDAY NIGHT BEFORE
ENCOMPASSING THE ENTIRE EASTERN CONUS BY FRIDAY NIGHT. UPPER LEVEL
RIDGING DURING THIS SAME TIME WILL LEAD TO PLENTY OF SUNSHINE AND
NEAR NORMAL TEMPS. WEAK SOUTHERLY FLOW WILL BEGIN TO DEVELOP AS THE
HIGH MOVES OFF THE COAST SATURDAY NIGHT AND SUNDAY WILL BRING ABOVE
NORMAL TEMPS IN LIGHT SOUTHERLY FLOW.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
CLOUDS WILL CONTINUE TO LOWER LATE THIS AFTERNOON AND EVENING AHEAD
OF AN APPROACHING LOW PRESSURE SYSTEM. PRECIP WILL BEGIN AROUND
MIDNIGHT...WITH IFR CONDITIONS GRADUALLY DEVELOPING BY DAYBREAK.
COULD BE LOWER AT TIMES. A PERIOD OF FZRA IS LIKELY AT THE
TERMINALS...BUT TEMPERATURES WILL BE VERY CLOSE TO FREEZING. IAD/MRB
HAVE THE GREATEST CHANCE AT A PROLONGED PERIOD OF ICING. THE THREAT
FOR ICING WILL DECREASE BETWEEN 12-15Z...WITH RAIN EXPECTED INTO THE
AFTERNOON AND CONTINUED IFR OR LOWER CONDITIONS. SOME IMPROVEMENT
POSSIBLE BY LATE AFTERNOON AS PRECIP TAPERS OFF. A COLD FRONT WILL
PASS THROUGH LATE IN THE DAY AND SHIFT LIGHT WINDS FROM S TO NW.
VFR CONDITIONS ARE EXPECTED TUESDAY INTO TUESDAY NIGHT. CONFIDENCE
IS LOW IN THE OCCURRENCE OF AVIATION HAZARDS THROUGH THE LONG TERM
PERIOD.
&&
.MARINE...
LIGHT SOUTHERLY WINDS WILL CONTINUE THROUGH TONIGHT AND MOST OF
MONDAY. AS A LOW PRESSURE SYSTEM APPROACHES THE WATER. PRECIPITATION
WILL MOVE IN LATE TONIGHT AND LAST THROUGH MONDAY. A PERIOD OF
FREEZING RAIN IS POSSIBLE...BUT A MAJORITY OF THE EVENT WILL BE
PLAIN RAIN ON THE WATERS. A COLD FRONT WILL MOVE THROUGH LATE IN THE
DAY AND SHIFT WINDS TO THE NW.
SMALL CRAFT CONDITIONS MAY BE POSSIBLE TUESDAY INTO TUESDAY NIGHT
ON ALL WATERS. A SMALL CRAFT ADVISORY MAY ALSO BE NECESSARY INTO
THE DAY WEDNESDAY WITH BREEZY NORTHERLY WINDS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR DCZ001.
MD...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR MDZ011-013-014-016>018-504-506-508.
FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
MONDAY FOR MDZ003>006-501>503-505-507.
VA...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR VAZ025>031-036>040-050>057-501>504-506>508.
FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
MONDAY FOR VAZ505.
WV...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR WVZ050-055-501>506.
FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
MONDAY FOR WVZ051>053.
MARINE...NONE.
&&
$$
SYNOPSIS...KRW
NEAR TERM...ADS
SHORT TERM...KRW
LONG TERM...CEB
AVIATION...ADS/CEB/KRW
MARINE...ADS/CEB/KRW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
123 PM EST SUN JAN 11 2015
.UPDATE...
ISSUED AT 109 PM EST SUN JAN 11 2015
LAKE EFFECT SNOW ADVISORY HAS BEEN ONCE AGAIN BEEN POSTED FOR THE
KEWEENAW PENINSULA /N HOUGHTON AND KEWEENAW COUNTY/ UNTIL 06Z
TONIGHT. THE 1-2IN/HR SNOWFALL RATES SHOULD BE DIMINISHING LATER
THIS AFTERNOON AND THE MAIN BANDS WILL SHIFT FARTHER S AS MORE NW
FLOW PUSHES IN. THE RE-INTRODUCTION OF COLDER AIR ALOFT SHOULD
BRING THE DGZ DOWN NEAR OR BELOW THE SFC. THE LARGE FLAKES WITH
RATIOS OF 25:1 WILL BE COME TO AN END...RETURNING TO NEAR 20:1.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST SUN JAN 11 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF PERSISTING
OVER ERN NAMERICA. HOWEVER...HEIGHTS HAVE BEEN RISING SIGNIFICANTLY
OVER THE ERN CONUS (00Z RAOBS SHOW 12HR 500MB HEIGHT RISES OF
100-200M FROM THE UPPER MISSISSIPPI VALLEY TO THE E COAST)...
INDICATING A RELAXATION OF THE RECENT VERY COLD PATTERN. UPSTREAM...
A SHORTWAVE TROF IS DROPPING S INTO SASKATCHEWAN/MANITOBA. THIS WILL
BE THE MAIN FEATURE OF INTEREST IN THE SHORT TERM AS IT SWINGS SE
INTO THE UPPER GREAT LAKES LATE TONIGHT/MON MORNING. 850MB TEMPS ARE
CURRENTLY AROUND -18C PER LATEST RUC ANALYSIS...AND THIS IS
CONTINUING TO SUPPORT LES OVER LAKE SUPERIOR. A SFC TROF...ENHANCED
BY THE RELATIVELY WARM WATERS...EXTENDS ACROSS LAKE SUPERIOR EARLY
THIS MORNING. OVER WRN LAKE SUPERIOR...LAND BREEZE ENHANCED FLOW
AHEAD OF TROF IS FOCUSING LES MOSTLY OFFSHORE OF WRN UPPER MI...
EXCEPT OVER THE KEWEENAW. TO THE E...LES IS WELL OFFSHORE WITH HINTS
OF A CONVERGENT DOMINANT BAND ALONG TROF TO THE E OF STANNARD ROCK.
MODELS SHOW THE SFC TROF CURRENTLY OVER LAKE SUPERIOR WEAKENING AND
DRIFTING SE TODAY. OVER WRN LAKE SUPERIOR...NOT MUCH CHANGE IN WIND
DIRECTION IS INDICATED AS THIS OCCURS. OVER ERN LAKE SUPERIOR...LES
WILL DRIFT SLOWLY S AS WINDS BECOME MORE WNW. AS A RESULT...SCT TO
NMRS -SHSN WILL LINGER OVER NW UPPER MI TODAY...MAINLY THE
KEWEENAW...WHILE TO THE E...-SHSN SHOULD SETTLE/DEVELOP SE AND AT
LEAST BRUSH THE SHORE E OF MUNISING. -SHSN WON`T PUSH TOO FAR INLAND
SINCE THERE IS LITTLE N COMPONENT TO THE WIND. WITH INVERSION AT
3-4KFT...LES WILL BE ON THE LIGHT SIDE. DGZ DOES DOMINATE THE
CONVECTIVE LAYER THOUGH...AND THIS WILL LEAD TO HIGHER SNOW TO WATER
RATIOS. MIGHT SEE A COUPLE OF INCHES WHERE LES IS MOST PERSISTENT
TODAY. MEANWHILE...AHEAD OF THE APPROACHING SHORTWAVE TROF...MODELS
SHOW STRENGTHENING OF A JET STREAK FROM NRN MN TO NEW ENGLAND/SRN
QUEBEC TODAY. RIGHT ENTRANCE OF THIS JET MAY PROVIDE SUFFICIENT
FORCING FOR A STREAK OF -SN/FLURRIES TO DEVELOP AND SPREAD FROM MN
TO NRN WI/SRN UPPER MI LATE THIS AFTN/EVENING. OVER THE LAST DAY OR
SO...ALL MODEL GUIDANCE HAS TRENDED TOWARD SHOWING THIS STREAK OF
-SN. LOW-LEVEL DRY AIR WILL BE A HINDRANCE...BUT GIVEN MODEL
TRENDS...AT LEAST SCHC POPS ARE WARRANTED LATE AFTN/EVENING ACROSS
THE SRN FCST AREA.
TONIGHT...SHORTWAVE WILL SWING SE...PASSING ACROSS THE UPPER LAKES
LATE TONIGHT/MON MORNING. SINCE BULK OF THE DEEP LAYER FORCING
PASSES TO THE NE AND THERE IS AN ABSENCE OF ANY MOISTURE INFLOW IN
ADVANCE OF THIS DISTURBANCE...ACCOMPANYING PCPN SHOULD BE LIMITED TO
AREAS NEAR LAKE SUPERIOR. VEERING FLOW TO THE NW AND 850MB TEMPS
FALLING BACK TO -20 TO -24C BY 12Z MON IN THE WAKE OF ATTENDANT COLD
FROPA WILL BRING AN INCREASE IN LES TONIGHT INTO MON MORNING.
GFS/NAM FCST SOUNDINGS SHOW LIMITED IMPACT ON INVERSION...ONLY
RISING TO NEAR 5KFT...WHICH IS A LITTLE SURPRISING SINCE THE DEEP
LAYER FORCING PER QVECTORS IS NOT THAT WEAK. FORCING AND DEGREE OF
OVERWATER INSTABILITY WARRANTS CATEGORICAL POPS FOR AREAS FAVORED BY
NW WINDS TONIGHT. FOR NOW...EXPECT 1-3 INCHES OF SNOW BY DAYBREAK
MON. THE LONGER FETCH INTO NCNTRL UPPER MI AND DEEPER DGZ THERE
SUGGEST GREATER COVERAGE OF 2-3 INCH AMOUNTS WILL BE FROM MUNISING
EASTWARD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 438 AM EST SUN JAN 11 2015
DECENT AGREEMENT THAT LARGE TROUGH OVER EASTERN CANADA GRADUALLY
LOSES ITS INFLUENCE OVER THE GREAT LAKES BY NEXT WEEKEND. A COUPLE OF
LAST PUSHES OF ARCTIC AIR WILL GIVE UPPER GREAT LAKES GLANCING BLOWS
OF COLDER TEMPS...FIRST ON MONDAY...THEN AGAIN ON THURSDAY. BY NEXT
WEEKEND ZONAL FLOW IS IN FULL SWING AS STRONG JET STREAK PLOWING
ACROSS THE PACIFIC MASHES HEIGHTS DOWN OVER THE WESTERN CONUS. H85
TEMPS AS LOW AS -24C ON MONDAY MORNING WILL BE REPLACED WITH VALUES
RISING ABOVE ZERO ON FRIDAY. EXPECT TEMPS TO BE WELL INTO THE 20S AT
THE SFC BY THE TIME WE REACH LATE THIS WEEK.
INITIAL BATCH OF COLD AIR TIED TO SHORTWAVE DROPPING OVER THE AREA
TONIGHT RESULTS IN LAKE EFFECT SNOW SHOWERS KICKING UP IN NNW-N FLOW
INTO MONDAY MORNING. LIMITED DIRECT IMPACT FM THE SHORTWAVE TO
ENHANCE THE LES. INVERSIONS UP TO 5KFT AND GENERAL UNIDIRECTIONAL
FLOW WITHIN THE CLOUD LAYER WILL AID IN ORGANIZATION. SINCE MUCH OF
CLOUD LAYER IS WITHIN THE DGZ COULD SEE FEW INCHES OF FLUFFY
ACCUMULATION. A NEGATIVE FACTOR WILL BE BLYR WINDS STEADILY VEERING
FM NW TO NNE LATE TONIGHT INTO MONDAY MORNING WHICH WILL NOT ALLOW
THE BANDS TO AFFECT ANY ONE LOCATION FOR TOO LONG OF A DURATION.
TIMING WILL MATTER AS IF THE STRONGER LES DROPS ALONG LK SUPERIOR
EARLIER ON MONDAY...THEN THE MORNING COMMUTE WOULD BE IMPACTED. MAY
MENTION IN HWO...BUT OVERALL SEEMS LIKE MAY BE ABLE TO GET BY WITHOUT
HAVING A HEADLINE FOR THE LES. INVERSIONS LOWER FURTHER BY MONDAY
AFTN BELOW 5KFT AND LOW-LEVEL CONVERGENCE WEAKENS AS LARGE HIGH
PRESSURE RIDGE OVER 1040MB BUILDS FM THE NORTHERN PLAINS TOWARD THE
WESTERN GREAT LAKES...SO LES WILL CONTINUE TO TREND DOWNWARD IN
INTENSITY.
BY MONDAY NIGHT WHATEVER IS LEFT OF THE LES SHOULD BE SPUTTERING
ALONG AS MAINLY FLURRIES FOR THE SNOW BELTS EAST OF MARQUETTE AS
WINDS BACK NW. RIDGE/DRY AIR AND CONTINUAL BACKING WINDS WILL END
LES OVERNIGHT. CALM BUT COLD CONDITIONS INLAND WITH THE RIDGING
OVERHEAD. A BIT MORE OF A GRADIENT WSW WIND KEEPS TEMPS NOT AS COLD
OVER THE KEWEENAW AND NEAR LK SUPERIOR. INLAND THOUGH...PWATS LESS
THAN 0.10 INCH AND CALM CONDITIONS WILL RESULT IN PRIME RADIATIONAL
COOLING WITH TYPICAL COLD SPOTS POSSIBLY DROPPING TO READINGS LOWER
THAN 20 BLO. THANKFULLY NO WIND CHILL ISSUES AS IT SHOULD BE CALM
WHERE TEMPS ARE THAT LOW.
RIDGE STILL ENOUGH IN VCNTY TUESDAY TO LIMIT MIXING DEPTH AND THUS
KEEP MAX TEMPS IN THE LOW-MID TEENS. EXCEPTION WILL BE ALONG LK
SUPERIOR WEST THROUGH NCNTRL WHERE WSW FLOW PROVIDES SOME DOWNSLOPE
WARMING AND COULD BOOST TEMPS ABOVE 20 DEGREES. A RELATIVE HEAT
WAVE COMPARED TO THE CHILL THAT HAS BEEN AROUND THE LAST WEEK OR SO.
WSW WINDS MAY GET GUSTY OVER LK SUPERIOR AND KEWEENAW ON TUESDAY
NIGHT. MAY SEE WINDS OVER 30 MPH FOR PARTS OF THE KEWEENAW. WINDS MAY
STAY STRONG ENOUGH TO RESULT IN TEMPS NEAR LK SUPERIOR STAYING STEADY
OR ONLY SLIGHTLY FALLING. INLAND OVER WEST HALF...BLENDED BACK TOWARD
GOING FORECAST WITH MINS SLIPPING BLO ZERO AS IT WOULD NOT TAKE MUCH
DECOUPLING TO HAVE TEMPS FALL OFF IN INTERIOR SHELTERED AREAS. COULD
SEE DECENT RANGE IN MIN TEMPS OVR THE CWA THIS NIGHT.
WEAK LOW PRESSURE TROUGH...EXTENSION FM STRONGER LOW PRESSURE TIED
TO SHORTWAVE OVER NORTHERN ONTARIO...CROSSES LK SUPERIOR ON
WEDNESDAY. GIVEN WEST-SOUTHWEST WINDS...BEST CHANCE OF ANY LGT SNOW
WOULD BE ON THE KEWEENAW. ONCE THE TROUGH SLIDES FARTHER OVER THE
AREA ON WEDNESDAY NIGHT INTO THURSDAY...SHOWED CHANCES ALONG MUCH OF
THE NORTHERN CWA. MARGINAL FM A STRICT LES STANDPOINT WITH H85 TEMPS
ONLY AROUND -12C...BUT BOTH GFS AND ECMWF HINT AT ADDITIONAL FORCING
AND MOISTENING...SO COULD BE LAKE ENHANCED SNOW FOR AT LEAST A BRIEF
PERIOD. TROUGH THEN BOUNCES EAST ON FRIDAY AND MAY EVEN TAKE SHAPE
AS A WARM FRONT...AT LEAST ALOFT. DOES SEEM THAT GFS AND ECMWF HINT
THAT THERE WOULD BE SW-W WINDS FOR FRIDAY WITH H85 TEMPS WARMING
ABOVE 0C. GFS SOUNDINGS INDICATE SHALLOW MIXING HEIGHT WITH MOST OF
THE WARMING STAYING ALOFT. INCREASED TEMPS A BIT OVER CONSENSUS WITH
THE HINTS SHOWING UP AND HAVE MID 20S INLAND AND A SHOT AT CRACKING
30 DEGREES ALONG LK SUPERIOR WITH THE SW WINDS. RAN TEMPS UP TO 30
DEGREES FOR NOW...BUT BIAS CORRECTED ECMWF GUIDANCE DID HAVE EVEN
MID 30S. LIKELY WOULD NEED TO HAVE DECENT SUNSHINE/MIXING FOR THAT
TO HAPPEN...BUT FOR NOW INCHED HIGH TEMPS UP SOME. LAST TIME NWS
OFFICE IN NEGAUNEE TOWNSHIP SAW A HIGH TEMP OF 30 DEGREES WAS JUST
AFTER CHRISTMAS ON THE MORNING OF 27 DEC. TEMPS WENT IN A FREE FALL
AFTER THAT THOUGH AND HAVE ONLY BEEN ABOVE 20 DEGREES DURING THE
DAYTIME HOURS ON ONE DAY...3 JAN. A FEW DAYS WITH HIGHS IN THE 20S
WOULD BE QUITE WELCOME.
NO ADJUSTMENTS TO CONSENSUS FORECAST FOR NEXT WEEKEND AS ECMWF IS
TRYING TO SHOW A STRONGER/DIGGIER SHORTWAVE AND STRONGER COLD FRONT
PASSAGE...WHILE THE GFS TURNS MORE PROGRESSIVE AND KEEPS TROUGH TO
THE NORTH SO THUS ANOTHER WARMER DAY. GEM-NH ON ITS LAST PANEL AT 00Z
SAT 17 JAN LOOKS MORE LIKE THE GFS. USED A BLEND FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 123 PM EST SUN JAN 11 2015
DESPITE LIGHTER WINDS THAN LATE...THE LARGE MORE PRISTINE SNOWFLAKES
HAVE STILL BEEN QUITE PRODUCTIVE AT REDUCING VIS AT CMX. HAVE HAD
REPORTS OF 1-2IN/HR SNOWFALL IN THE DOMINANT BAND OF LAKE EFFECT
SNOW SET UP TO THE W AND NW OF CMX. THIS BAND WILL LIKELY SHIFT
ACROSS CMX LATER THIS AFTERNOON...WITH VIS LINGERING AROUND 1SM INTO
THE EVENING HOURS. LATER TONIGHT NW WINDS WILL SLOWLY PUSH IN BEHIND
A COLD FRONT DROPPING THROUGH THE AREA. THE BEST CHANCE OF SNOW WILL
THEN SHIFT FARTHER S OF CMX AFTER 04-06Z...WITH CEILINGS GOING BACK
TO MVFR TO HIGH END IFR.
IWD WILL STAY VFR UNTIL MORE WNW-N FLOW PUSHES LAKE EFFECT SNOW
SHOWERS INTO THE AREA AROUND/AFTER 08Z MONDAY. LOOK FOR NEAR IFR
CEILING/VIS TO LINGER THROUGH 18Z MONDAY.
AT SAW...THE N FLOW BRING -SHSN BY 06Z...WITH IFR CONDITIONS
EXPECTED TO BEGIN BETWEEN 12-16Z MONDAY AS BETTER CONVERGENCE SETS
UP ON MAINLY N FLOW OFF LAKE SUPERIOR BEHIND THE PASSING COLD FRONT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST SUN JAN 11 2015
WINDS HAVE DIMINISHED BLO 25 KTS AND WILL STAY THAT WAY THROUGH MOST
OF TONIGHT EVEN AS LOW PRESSURE TROUGH WORKS ACROSS THE LAKE. STRONGER
COLD FRONT SWEEPS OVER LK SUPERIOR LATE TONIGHT AND EXPECT WINDS TO
SHIFT TO THE NORTH AND PEAK AROUND 30 KTS AROUND SUNRISE ON MONDAY...BEFORE
QUICKLY DIMINISHING TO LESS THAN 20 KTS ON MONDAY AFTN. HEAVY FREEZING
SPRAY WILL RETURN LATE TONIGHT BUT UNLIKE LAST WEEK...IT WILL NOT
LAST LONG...ENDING BY MONDAY EVENING AS HIGH PRESSURE DRIFTS ACROSS.
WINDS WILL INCREASE AGAIN LATE MONDAY NIGHT INTO TUESDAY OUT OF THE
SOUTHWEST. STRONGEST WINDS TO 30 KTS EXPECTED OVER WESTERN AND NORTH
CENTRAL LK SUPERIOR. COULD SEE GALE GUSTS TUESDAY AFTN INTO TUESDAY
EVENING BTWN TIP OF KEWEENAW AND ISLE ROYALE. HEAVY FREEZING SPRAY IS
NOT EXPECTED AS WILL BE HIGHER THAN SEEN RECENTLY. WINDS DIMINISH TO
25 KTS OR LESS BY WEDNESDAY AND SHOULD REMAIN AT SIMILAR SPEEDS
THROUGH LATE THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST MONDAY FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 4 PM EST MONDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TO 1 PM EST MONDAY FOR
LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 1 PM EST MONDAY FOR
LSZ242-263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...KF
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
111 PM EST SUN JAN 11 2015
.UPDATE...
ISSUED AT 109 PM EST SUN JAN 11 2015
LAKE EFFECT SNOW ADVISORY HAS BEEN ONCE AGAIN BEEN POSTED FOR THE
KEWEENAW PENINSULA /N HOUGHTON AND KEWEENAW COUNTY/ UNTIL 06Z
TONIGHT. THE 1-2IN/HR SNOWFALL RATES SHOULD BE DIMINISHING LATER
THIS AFTERNOON AND THE MAIN BANDS WILL SHIFT FARTHER S AS MORE NW
FLOW PUSHES IN. THE RE-INTRODUCTION OF COLDER AIR ALOFT SHOULD
BRING THE DGZ DOWN NEAR OR BELOW THE SFC. THE LARGE FLAKES WITH
RATIOS OF 25:1 WILL BE COME TO AN END...RETURNING TO NEAR 20:1.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 517 AM EST SUN JAN 11 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF PERSISTING
OVER ERN NAMERICA. HOWEVER...HEIGHTS HAVE BEEN RISING SIGNIFICANTLY
OVER THE ERN CONUS (00Z RAOBS SHOW 12HR 500MB HEIGHT RISES OF
100-200M FROM THE UPPER MISSISSIPPI VALLEY TO THE E COAST)...
INDICATING A RELAXATION OF THE RECENT VERY COLD PATTERN. UPSTREAM...
A SHORTWAVE TROF IS DROPPING S INTO SASKATCHEWAN/MANITOBA. THIS WILL
BE THE MAIN FEATURE OF INTEREST IN THE SHORT TERM AS IT SWINGS SE
INTO THE UPPER GREAT LAKES LATE TONIGHT/MON MORNING. 850MB TEMPS ARE
CURRENTLY AROUND -18C PER LATEST RUC ANALYSIS...AND THIS IS
CONTINUING TO SUPPORT LES OVER LAKE SUPERIOR. A SFC TROF...ENHANCED
BY THE RELATIVELY WARM WATERS...EXTENDS ACROSS LAKE SUPERIOR EARLY
THIS MORNING. OVER WRN LAKE SUPERIOR...LAND BREEZE ENHANCED FLOW
AHEAD OF TROF IS FOCUSING LES MOSTLY OFFSHORE OF WRN UPPER MI...
EXCEPT OVER THE KEWEENAW. TO THE E...LES IS WELL OFFSHORE WITH HINTS
OF A CONVERGENT DOMINANT BAND ALONG TROF TO THE E OF STANNARD ROCK.
MODELS SHOW THE SFC TROF CURRENTLY OVER LAKE SUPERIOR WEAKENING AND
DRIFTING SE TODAY. OVER WRN LAKE SUPERIOR...NOT MUCH CHANGE IN WIND
DIRECTION IS INDICATED AS THIS OCCURS. OVER ERN LAKE SUPERIOR...LES
WILL DRIFT SLOWLY S AS WINDS BECOME MORE WNW. AS A RESULT...SCT TO
NMRS -SHSN WILL LINGER OVER NW UPPER MI TODAY...MAINLY THE
KEWEENAW...WHILE TO THE E...-SHSN SHOULD SETTLE/DEVELOP SE AND AT
LEAST BRUSH THE SHORE E OF MUNISING. -SHSN WON`T PUSH TOO FAR INLAND
SINCE THERE IS LITTLE N COMPONENT TO THE WIND. WITH INVERSION AT
3-4KFT...LES WILL BE ON THE LIGHT SIDE. DGZ DOES DOMINATE THE
CONVECTIVE LAYER THOUGH...AND THIS WILL LEAD TO HIGHER SNOW TO WATER
RATIOS. MIGHT SEE A COUPLE OF INCHES WHERE LES IS MOST PERSISTENT
TODAY. MEANWHILE...AHEAD OF THE APPROACHING SHORTWAVE TROF...MODELS
SHOW STRENGTHENING OF A JET STREAK FROM NRN MN TO NEW ENGLAND/SRN
QUEBEC TODAY. RIGHT ENTRANCE OF THIS JET MAY PROVIDE SUFFICIENT
FORCING FOR A STREAK OF -SN/FLURRIES TO DEVELOP AND SPREAD FROM MN
TO NRN WI/SRN UPPER MI LATE THIS AFTN/EVENING. OVER THE LAST DAY OR
SO...ALL MODEL GUIDANCE HAS TRENDED TOWARD SHOWING THIS STREAK OF
-SN. LOW-LEVEL DRY AIR WILL BE A HINDRANCE...BUT GIVEN MODEL
TRENDS...AT LEAST SCHC POPS ARE WARRANTED LATE AFTN/EVENING ACROSS
THE SRN FCST AREA.
TONIGHT...SHORTWAVE WILL SWING SE...PASSING ACROSS THE UPPER LAKES
LATE TONIGHT/MON MORNING. SINCE BULK OF THE DEEP LAYER FORCING
PASSES TO THE NE AND THERE IS AN ABSENCE OF ANY MOISTURE INFLOW IN
ADVANCE OF THIS DISTURBANCE...ACCOMPANYING PCPN SHOULD BE LIMITED TO
AREAS NEAR LAKE SUPERIOR. VEERING FLOW TO THE NW AND 850MB TEMPS
FALLING BACK TO -20 TO -24C BY 12Z MON IN THE WAKE OF ATTENDANT COLD
FROPA WILL BRING AN INCREASE IN LES TONIGHT INTO MON MORNING.
GFS/NAM FCST SOUNDINGS SHOW LIMITED IMPACT ON INVERSION...ONLY
RISING TO NEAR 5KFT...WHICH IS A LITTLE SURPRISING SINCE THE DEEP
LAYER FORCING PER QVECTORS IS NOT THAT WEAK. FORCING AND DEGREE OF
OVERWATER INSTABILITY WARRANTS CATEGORICAL POPS FOR AREAS FAVORED BY
NW WINDS TONIGHT. FOR NOW...EXPECT 1-3 INCHES OF SNOW BY DAYBREAK
MON. THE LONGER FETCH INTO NCNTRL UPPER MI AND DEEPER DGZ THERE
SUGGEST GREATER COVERAGE OF 2-3 INCH AMOUNTS WILL BE FROM MUNISING
EASTWARD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 438 AM EST SUN JAN 11 2015
DECENT AGREEMENT THAT LARGE TROUGH OVER EASTERN CANADA GRADUALLY
LOSES ITS INFLUENCE OVER THE GREAT LAKES BY NEXT WEEKEND. A COUPLE OF
LAST PUSHES OF ARCTIC AIR WILL GIVE UPPER GREAT LAKES GLANCING BLOWS
OF COLDER TEMPS...FIRST ON MONDAY...THEN AGAIN ON THURSDAY. BY NEXT
WEEKEND ZONAL FLOW IS IN FULL SWING AS STRONG JET STREAK PLOWING
ACROSS THE PACIFIC MASHES HEIGHTS DOWN OVER THE WESTERN CONUS. H85
TEMPS AS LOW AS -24C ON MONDAY MORNING WILL BE REPLACED WITH VALUES
RISING ABOVE ZERO ON FRIDAY. EXPECT TEMPS TO BE WELL INTO THE 20S AT
THE SFC BY THE TIME WE REACH LATE THIS WEEK.
INITIAL BATCH OF COLD AIR TIED TO SHORTWAVE DROPPING OVER THE AREA
TONIGHT RESULTS IN LAKE EFFECT SNOW SHOWERS KICKING UP IN NNW-N FLOW
INTO MONDAY MORNING. LIMITED DIRECT IMPACT FM THE SHORTWAVE TO
ENHANCE THE LES. INVERSIONS UP TO 5KFT AND GENERAL UNIDIRECTIONAL
FLOW WITHIN THE CLOUD LAYER WILL AID IN ORGANIZATION. SINCE MUCH OF
CLOUD LAYER IS WITHIN THE DGZ COULD SEE FEW INCHES OF FLUFFY
ACCUMULATION. A NEGATIVE FACTOR WILL BE BLYR WINDS STEADILY VEERING
FM NW TO NNE LATE TONIGHT INTO MONDAY MORNING WHICH WILL NOT ALLOW
THE BANDS TO AFFECT ANY ONE LOCATION FOR TOO LONG OF A DURATION.
TIMING WILL MATTER AS IF THE STRONGER LES DROPS ALONG LK SUPERIOR
EARLIER ON MONDAY...THEN THE MORNING COMMUTE WOULD BE IMPACTED. MAY
MENTION IN HWO...BUT OVERALL SEEMS LIKE MAY BE ABLE TO GET BY WITHOUT
HAVING A HEADLINE FOR THE LES. INVERSIONS LOWER FURTHER BY MONDAY
AFTN BELOW 5KFT AND LOW-LEVEL CONVERGENCE WEAKENS AS LARGE HIGH
PRESSURE RIDGE OVER 1040MB BUILDS FM THE NORTHERN PLAINS TOWARD THE
WESTERN GREAT LAKES...SO LES WILL CONTINUE TO TREND DOWNWARD IN
INTENSITY.
BY MONDAY NIGHT WHATEVER IS LEFT OF THE LES SHOULD BE SPUTTERING
ALONG AS MAINLY FLURRIES FOR THE SNOW BELTS EAST OF MARQUETTE AS
WINDS BACK NW. RIDGE/DRY AIR AND CONTINUAL BACKING WINDS WILL END
LES OVERNIGHT. CALM BUT COLD CONDITIONS INLAND WITH THE RIDGING
OVERHEAD. A BIT MORE OF A GRADIENT WSW WIND KEEPS TEMPS NOT AS COLD
OVER THE KEWEENAW AND NEAR LK SUPERIOR. INLAND THOUGH...PWATS LESS
THAN 0.10 INCH AND CALM CONDITIONS WILL RESULT IN PRIME RADIATIONAL
COOLING WITH TYPICAL COLD SPOTS POSSIBLY DROPPING TO READINGS LOWER
THAN 20 BLO. THANKFULLY NO WIND CHILL ISSUES AS IT SHOULD BE CALM
WHERE TEMPS ARE THAT LOW.
RIDGE STILL ENOUGH IN VCNTY TUESDAY TO LIMIT MIXING DEPTH AND THUS
KEEP MAX TEMPS IN THE LOW-MID TEENS. EXCEPTION WILL BE ALONG LK
SUPERIOR WEST THROUGH NCNTRL WHERE WSW FLOW PROVIDES SOME DOWNSLOPE
WARMING AND COULD BOOST TEMPS ABOVE 20 DEGREES. A RELATIVE HEAT
WAVE COMPARED TO THE CHILL THAT HAS BEEN AROUND THE LAST WEEK OR SO.
WSW WINDS MAY GET GUSTY OVER LK SUPERIOR AND KEWEENAW ON TUESDAY
NIGHT. MAY SEE WINDS OVER 30 MPH FOR PARTS OF THE KEWEENAW. WINDS MAY
STAY STRONG ENOUGH TO RESULT IN TEMPS NEAR LK SUPERIOR STAYING STEADY
OR ONLY SLIGHTLY FALLING. INLAND OVER WEST HALF...BLENDED BACK TOWARD
GOING FORECAST WITH MINS SLIPPING BLO ZERO AS IT WOULD NOT TAKE MUCH
DECOUPLING TO HAVE TEMPS FALL OFF IN INTERIOR SHELTERED AREAS. COULD
SEE DECENT RANGE IN MIN TEMPS OVR THE CWA THIS NIGHT.
WEAK LOW PRESSURE TROUGH...EXTENSION FM STRONGER LOW PRESSURE TIED
TO SHORTWAVE OVER NORTHERN ONTARIO...CROSSES LK SUPERIOR ON
WEDNESDAY. GIVEN WEST-SOUTHWEST WINDS...BEST CHANCE OF ANY LGT SNOW
WOULD BE ON THE KEWEENAW. ONCE THE TROUGH SLIDES FARTHER OVER THE
AREA ON WEDNESDAY NIGHT INTO THURSDAY...SHOWED CHANCES ALONG MUCH OF
THE NORTHERN CWA. MARGINAL FM A STRICT LES STANDPOINT WITH H85 TEMPS
ONLY AROUND -12C...BUT BOTH GFS AND ECMWF HINT AT ADDITIONAL FORCING
AND MOISTENING...SO COULD BE LAKE ENHANCED SNOW FOR AT LEAST A BRIEF
PERIOD. TROUGH THEN BOUNCES EAST ON FRIDAY AND MAY EVEN TAKE SHAPE
AS A WARM FRONT...AT LEAST ALOFT. DOES SEEM THAT GFS AND ECMWF HINT
THAT THERE WOULD BE SW-W WINDS FOR FRIDAY WITH H85 TEMPS WARMING
ABOVE 0C. GFS SOUNDINGS INDICATE SHALLOW MIXING HEIGHT WITH MOST OF
THE WARMING STAYING ALOFT. INCREASED TEMPS A BIT OVER CONSENSUS WITH
THE HINTS SHOWING UP AND HAVE MID 20S INLAND AND A SHOT AT CRACKING
30 DEGREES ALONG LK SUPERIOR WITH THE SW WINDS. RAN TEMPS UP TO 30
DEGREES FOR NOW...BUT BIAS CORRECTED ECMWF GUIDANCE DID HAVE EVEN
MID 30S. LIKELY WOULD NEED TO HAVE DECENT SUNSHINE/MIXING FOR THAT
TO HAPPEN...BUT FOR NOW INCHED HIGH TEMPS UP SOME. LAST TIME NWS
OFFICE IN NEGAUNEE TOWNSHIP SAW A HIGH TEMP OF 30 DEGREES WAS JUST
AFTER CHRISTMAS ON THE MORNING OF 27 DEC. TEMPS WENT IN A FREE FALL
AFTER THAT THOUGH AND HAVE ONLY BEEN ABOVE 20 DEGREES DURING THE
DAYTIME HOURS ON ONE DAY...3 JAN. A FEW DAYS WITH HIGHS IN THE 20S
WOULD BE QUITE WELCOME.
NO ADJUSTMENTS TO CONSENSUS FORECAST FOR NEXT WEEKEND AS ECMWF IS
TRYING TO SHOW A STRONGER/DIGGIER SHORTWAVE AND STRONGER COLD FRONT
PASSAGE...WHILE THE GFS TURNS MORE PROGRESSIVE AND KEEPS TROUGH TO
THE NORTH SO THUS ANOTHER WARMER DAY. GEM-NH ON ITS LAST PANEL AT 00Z
SAT 17 JAN LOOKS MORE LIKE THE GFS. USED A BLEND FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 652 AM EST SUN JAN 11 2015
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO AFFECT KCMX TODAY UNDER
WNW WINDS. THERE IS SOME UNCERTAINTY IN VIS/CIG IMPACTS...BUT SINCE
CONDITIONS FAVOR MOSTLY LIGHT PCPN...EXPECT MVFR CONDITIONS TO
PREVAIL WITH SOME BRIEF PERIODS OF IFR. COLD FRONT PASSING THIS
EVENING WILL LIKELY BRING A PERIOD OF IFR CONDITIONS TO KCMX...AND
POTENTIALLY LIFR. AS WINDS SHIFT TOWARD A NORTHERLY DIRECTION
OVERNIGHT WHICH IS TYPICALLY LESS FAVORABLE FOR POOR
CONDITIONS/PERSISTENT HEAVIER SNOW SHOWERS AT KCMX...EXPECT MVFR
CONDITIONS TO RETURN. AT KIWD/KSAW...VFR CONDITIONS WILL PREVAIL
INTO THE EVENING HRS AS LOW-LEVEL AIR MASS REMAINS RELATIVELY DRY.
AS WINDS SHIFT NW TONIGHT IN ASSOCIATION WITH COLD FROPA...LAKE
EFFECT SNOW SHOWERS WILL INCREASE AT KIWD...DROPPING CONDITIONS TO
IFR LATE. AT KSAW...EXPECT MVFR CONDITIONS TO DEVELOP OVERNIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EST SUN JAN 11 2015
WINDS HAVE DIMINISHED BLO 25 KTS AND WILL STAY THAT WAY THROUGH MOST
OF TONIGHT EVEN AS LOW PRESSURE TROUGH WORKS ACROSS THE LAKE. STRONGER
COLD FRONT SWEEPS OVER LK SUPERIOR LATE TONIGHT AND EXPECT WINDS TO
SHIFT TO THE NORTH AND PEAK AROUND 30 KTS AROUND SUNRISE ON MONDAY...BEFORE
QUICKLY DIMINISHING TO LESS THAN 20 KTS ON MONDAY AFTN. HEAVY FREEZING
SPRAY WILL RETURN LATE TONIGHT BUT UNLIKE LAST WEEK...IT WILL NOT
LAST LONG...ENDING BY MONDAY EVENING AS HIGH PRESSURE DRIFTS ACROSS.
WINDS WILL INCREASE AGAIN LATE MONDAY NIGHT INTO TUESDAY OUT OF THE
SOUTHWEST. STRONGEST WINDS TO 30 KTS EXPECTED OVER WESTERN AND NORTH
CENTRAL LK SUPERIOR. COULD SEE GALE GUSTS TUESDAY AFTN INTO TUESDAY
EVENING BTWN TIP OF KEWEENAW AND ISLE ROYALE. HEAVY FREEZING SPRAY IS
NOT EXPECTED AS WILL BE HIGHER THAN SEEN RECENTLY. WINDS DIMINISH TO
25 KTS OR LESS BY WEDNESDAY AND SHOULD REMAIN AT SIMILAR SPEEDS
THROUGH LATE THIS WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST MONDAY FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 4 PM EST MONDAY FOR
LSZ248>251-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM TO 1 PM EST MONDAY FOR
LSZ243-244-264.
HEAVY FREEZING SPRAY WARNING FROM 4 AM TO 1 PM EST MONDAY FOR
LSZ242-263.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1208 PM CST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1207 PM CST SUN JAN 11 2015
LETS ADMIT IT: OVERALL TODAY IS TURNING OUT TO BE A SOMEWHAT
NICER DAY THAN ANTICIPATED 24 HOURS AGO...WITH MOSTLY SUNNY SKIES
AND LARGELY AS A RESULT...WARMER TEMPERATURES. HAVE TO GIVE A BIG
KUDOS TO NIGHT SHIFT FORECASTER WHO CRANKED UP HIGH TEMPS 7-9
DEGREES FROM PREVIOUS FORECAST. ALTHOUGH THIS MAY END UP BEING A
TOUCH TOO WARM IN A FEW SPOTS...BASED ON TRENDS SO FAR TODAY OPTED
TO MAKE NO CHANGE WHATSOEVER AND LET THESE HIGHS RIDE...WHICH
RANGE FROM UPPER 20S NORTH...NEAR-30 TRI-CITIES AND LOW 40S NEAR
AND SOUTH OF THE STATE LINE. AM KEEPING A CLOSE EYE ON AN
EXPANSIVE DECK OF LOWER STRATUS OVER SOUTHERN KS THAT IS SLOWLY-
BUT-SURELY PUSHING NORTH-NORTHEAST...BUT SHORT TERM MODELS SUCH AS
THE RAP13/HRRR BARELY BRUSH THIS LOWER CLOUD DECK INTO THE FAR
SOUTH/SOUTHEASTERN CWA IN KS ZONES...IF EVEN AT ALL LATER
TODAY/THIS EVENING. EVENTUALLY THIS AFTERNOON...A SOMEWHAT
STEADIER NORTH BREEZE WILL FINALLY BECOME ESTABLISHED AS MODEST
PRESSURE RISES MOVE SOUTHWARD INTO THE AREA FROM THE EXPANSIVE
SURFACE HIGH CURRENTLY CENTERED FROM NORTHEAST MONTANA NORTHWARD.
LEGIT LOW LEVEL COLD AIR ADVECTION DOES NOT REALLY KICK IN THOUGH
UNTIL VERY LATE THIS AFTERNOON/THIS EVENING...
NO FORECAST CHANGES POSTED YET BEYOND 00Z/6PM THIS EVENING...
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 253 AM CST SUN JAN 11 2015
THE FOCUS DURING THE SHORT TERM PERIODS WILL AGAIN BE CENTERED
AROUND CLOUDS AND TEMPERATURES. THE PATTERN ALOFT FEATURED
WESTERLY FLOW ACROSS OUR REGION WITH EMBEDDED WAVES IN THE FLOW.
ONE SUCH WAVE WAS TRANSLATING ACROSS KS...WHICH WILL HAVE LITTLE
CONSEQUENCE FOR OUR AREA. FARTHER NORTH ENERGY MOVING SOUTH FM
CANADA WAS MOVING SOUTH INTO THE NORTHERN PLAINS AND THIS WILL
SEND A REINFORCING COLD FRONT ACROSS THE PLAINS LATE THIS AFTN AND
TONIGHT.
CURRENT CONDITIONS AS OF 08Z PLACED A COOL FRONTAL BOUNDARY JUST
SOUTH OF THE PLATTE RIVER. TEMPERATURES BEHIND THE FRONT AVERAGED IN
THE SINGLE DIGITS AND TEENS WHILE AHEAD OF THE BOUNDARY READINGS
AVERAGED IN THE MIDDLE 20S. SO FAR FOG HAS YET TO FORM AND IF TRENDS
CONTINUE WILL REMOVE MENTION FOR THE EARLY MORNING HOURS.
WITH NO REAL PUSH OF THE FRONT TODAY...THE BOUNDARY IS ONLY EXPECTED
TO GRADUALLY SAG SOUTH INTO OUR SOUTHERN ZONES LATE THIS AFTN OR
EARLY EVENING. AHEAD OF THE FRONT TEMPS COULD EASILY BE QUITE
MILD IN THE 40S ACROSS MUCH OF KS...SIMILAR TO RAP DEPICTION BUT
THIS WILL ALSO BE DEPENDENT UPON CLOUD COVER. THE NAM IS ALSO ROBUST
WITH LLVL MOISTURE AND LOW CLOUDS LIFTING NORTH AHEAD OF THE
APPROACHING SHORTWAVE AND SURGES MOISTURE NORTH OF THE FRONT. THE
GFS KEEPS THE BRUNT OF THE CLOUDS SOUTH OF THE BOUNDARY. THE NAM
IS STILL SUFFERING FROM OVERZEALOUS SNOWPACK INITIALIZATION AND
LLVL MOISTURE FIELDS LIKELY DUE TO POTENTIAL SNOW MELT AND HAD TO
SHY AWAY FROM IT FOR THIS FORECAST. FOR THE FORECAST TODAY...HAVE
WENT WITH VARYING CLOUD COVER THRU THE FIRST PART OF THE AFTN WITH
TEMPS SIMILAR TO RAP WITH READINGS RANGING FROM THE UPPER 20S IN
OUR NORTHERN CWA (NORTH OF FRONT) TO TEMPS IN THE 40S ACROSS MUCH
OF NORTH CENTRAL KS (SOUTH OF BOUNDARY). CLOUD COVER WILL INCREASE
AND TEMPS COOL N/S WITH ARRIVAL OF SECONDARY COLD FRONT LATER THIS
AFTN AND TONIGHT.
CLOUD COVER WITH FRONT/WAVE WILL BE AT MID/HIGH LEVELS SO NOT
LOOKING FOR PCPN WITH THE SECONDARY COLD FRONT THIS EVENING/TONIGHT.
COLDER CONDITIONS WILL SETTLE IN DURING THE NIGHT AS A 1045 MB
SURFACE HIGH BUILDS SOUTH FM THE DAKOTAS. THE AIRMASS CHANGE IS A
DROP OF NEARLY 10C AT H85 FROM THIS MORNING TO MONDAY MORNING.
OVERNIGHT LOWS PRIMARILY IN THE SINGLE DIGITS COMBINED WITH A STEADY
NORTH WIND WILL PRODUCE WIND CHILLS BELOW ZERO BUT VALUES ARE NOT
LOOKING QUITE COLD ENOUGH FOR AN HWO MENTION ATTM.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 253 AM CST SUN JAN 11 2015
PRIMARY FORECAST CONCERNS THROUGH THE LONG TERM LIE WITH
TEMPERATURES AND EARLY WEEK PRECIPITATION CHANCES.
MONDAY STILL ON TRACK TO BE THE COLDEST DAY OF THE FORECAST
PERIOD...WITH MODELS IN GOOD AGREEMENT SHOWING THE CWA BEING ON THE
SOUTHERN END OF AN UPPER LEVEL TROUGH AXIS EXTENDING BACK UP INTO
THE HUDSON BAY AREA. THIS TROUGH CONTINUES TO SWING THROUGH/EAST OF
THE CWA DURING THE DAYTIME HOURS MONDAY...WITH ZONAL TO SLIGHT NWRLY
FLOW BUILDING IN BEHIND. EVEN WITH THIS TROUGH SWINGING
THROUGH...MODELS NOT SHOWING AN ABUNDANCE OF MOISTURE AND CONTINUE
TO KEEP CONDITIONS DRY. THIS SYSTEM BRINGS A REINFORCING SHOT OF
NRLY WINDS AND COLDER AIR...SPEEDS ARE ONLY TOPPING OUT AROUND 10 TO
15 MPH IN THE MORNING...BUT WILL DIMINISH WITH TIME AS SFC HIGH
PRESSURE SETTLES FURTHER SOUTH. THE CENTER OF THE SFC HIGH REMAINS
OFF TO THE N/NE OF THE CWA...ENDING UP OVER FAR NERN NEB AT
00Z...THEN SHIFTS OVER TO THE CENTRAL PORTIONS OF THE IA/MN BORDER
BY TUESDAY MORNING...WHICH WILL BRING A GRADUAL TRANSITION IN WINDS
TO THE EAST THAN MORE SOUTHERLY BY 12Z TUESDAY. DID NOT MAKE NOTABLE
CHANGES TO INHERITED HIGHS FOR MONDAY...WHICH RANGE FROM THE LOWER
TEENS IN THE FAR NORTH TO LOWER 20S ACROSS NC KS. OVERNIGHT LOWS
MONDAY NIGHT/TUESDAY MORNING LOOK TO BOTTOM OUT IN THE SINGLE DIGITS
BELOW ZERO IN THE NORTHEAST TO NEAR 10 DEGREES IN THE FAR SW.
TUESDAY/TUESDAY NIGHT...MAIN STORY LIES WITH AN UPPER LEVEL
DISTURBANCE WHICH BY SUNRISE TUESDAY HAS DUG SOUTH INTO THE CENTRAL
ROCKIES/4 CORNERS REGION...WITH ZONAL FLOW IN PLACE ACROSS OUR AREA.
THROUGH THE DAYTIME HOURS...MODELS IN DECENT AGREEMENT SHOWING A
CLOSED CIRCULATION DEVELOPING OVER THE 4 CORNERS REGION...AND
TREKKING MAINLY EAST INTO THE TUESDAY NIGHT PERIOD...BUT ALSO
FILLING WITH TIME. THE 00Z ECMWF/GFS/GEM ARE ALL IN PRETTY GOOD
AGREEMENT SHOWING THE BRUNT OF THIS SYSTEM SLIDING TO THE SOUTH OF
THE CWA...BARELY GETTING CLIPPED BY THE NRN EDGE OF
PRECIPITATION...IF AT ALL. DISCOUNTED THE 00Z NAM...WHICH WAS
NOTABLY FURTHER NORTH AND DEEPER WITH THE SYSTEM...AND SHOWED SOME
LOCATIONS GETTING UPWARDS OF 4 INCHES OF SNOW. THE 06Z RUN HAS COME
MORE IN LINE WITH THE ECMWF/GFS/GEM. CONTINUED TO KEEP SOME 30-40
POPS CONFINED TO THE FAR S/SWRN PORTIONS OF THE CWA...WITH SOME 20
POPS BUFFERING THAT AREA TO THE NORTH. AT THIS POINT...IF SNOW DOES
MAKE IT FAR ENOUGH NORTH TO AFFECT OUR CWA...NOT EXPECTING MUCH IN
THE WAY OF ACCUMULATION. EXPECTING A BUMP UP IN TEMPS...WITH HIGHS
CURRENTLY FORECAST TO REACH THE LOWER 20S.
THROUGH THE REMAINDER OF THE LONG TERM PERIOD...WEDNESDAY THROUGH
SATURDAY...THE FORECAST CONTINUES TO BE A DRY ONE...WITH MODELS IN
DECENT AGREEMENT SHOWING NORTHWESTERLY FLOW DEVELOPING FOR WED/THURS
THANKS TO AT LEAST BRIEF RIDGING OVER THE WRN CONUS...BEFORE
BECOMING MORE ZONAL INTO FRI/SAT WITH AN APPROACHING DISTURBANCE
FROM THE NW. EXPECTING MODERATING TEMPERATURES ALOFT TO WORK THEIR
WAY IN FROM THE WEST...AND ALONG WITH THE POTENTIAL FOR MORE
DOWNSLOPING WRLY WINDS ESP THURS/FRI...TEMPS CLIMB A BIT EACH
DAY...AND ARE FORECAST BACK IN THE LOW/MID 40S CWA-WIDE FOR FRIDAY.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1207 PM CST SUN JAN 11 2015
CONFIDENCE IS QUITE HIGH IN PRECIPITATION-FREE WEATHER AND VFR
VISIBILITY THROUGH THE NEXT 24 HOURS...WHILE CONFIDENCE IS
REASONABLY HIGH (BUT NOT AS HIGH) IN VFR CEILING LASTING
THROUGHOUT. SURFACE HIGH PRESSURE BUILDING SOUTHWARD FROM THE
NORTHERN PLAINS WILL ALLOW INITIALLY LIGHT EASTERLY BREEZES EARLY
THIS AFTERNOON TO BECOME BETTER ESTABLISHED FROM A NORTHERLY
DIRECTION LATER THIS AFTERNOON INTO THIS EVENING...WITH AT LEAST A
FEW HOURS OF GUST POTENTIAL TO AROUND 18KT. MAINLY DURING A 5-HOUR
WINDOW FROM 23Z-04Z...SOME MODELS SUGGEST THAT AT LEAST A BRIEF
MVFR CEILING COULD PASS THROUGH THE AREA...BUT GIVEN THE TRACK
RECORD OF SOME MODELS/GUIDANCE THE PAST 24 HOURS ALONG WITH ALMOST
NO UPSTREAM EVIDENCE OF THIS...HAVE KEPT THE TAFS VFR FOR NOW BUT
WHILE HINTING AT THE MVFR POSSIBILITY WITH A "SCT010" MENTION.
BREEZES WILL REMAIN NORTHERLY THROUGH THE NIGHT AND INTO MONDAY
MORNING...BUT WITH A SUBTLE DECREASE IN SPEEDS AS THE HIGH
PRESSURE CENTER EDGES CLOSER.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...FAY
LONG TERM...ADP
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
905 AM PST SUN JAN 11 2015
.SYNOPSIS...UNSETTLED WEATHER WILL CONTINUE ACROSS THE REGION
THROUGH MONDAY AS TWO SYSTEMS PUSH THROUGH. THE FIRST WILL BRING
PRECIPITATION ACROSS MUCH OF THE MOJAVE DESERT TODAY. THE SECOND
WILL PUSH ACROSS THE SOUTHERN GREAT BASIN INTO UTAH AND ARIZONA
MONDAY BRINGING ADDITIONAL CHANCES FOR PRECIPITATION TO THOSE AREAS.
DRY AND PLEASANT WEATHER WILL RETURN TUESDAY THROUGH NEXT WEEK.
&&
.UPDATE...A BROAD ARC OF PRECIPITATION COULD BE SEEN ON MOSAIC RADAR
LOOPS EXTENDING FROM THE SOUTHERN CALIFORNIA COAST ACROSS
WESTERN AND NORTHERN SAN BERNARDINO COUNTY INTO CLARK COUNTY NEVADA
THIS MORNING. THE LATEST HRRR AND NAM/GFS QPF DEPICTIONS INDICATE
THIS ARC...ON THE NORTHERN PERIPHERY OF A CIRCULATION CURRENTLY
CENTERED NEAR LOS ANGELES...WILL SLOWLY MIGRATE TO THE EAST TODAY
THEN SLOWLY LOSE DEFINITION THIS EVENING AS THE ASSOCIATED
CIRCULATION MOVES INTO SOUTHERN ARIZONA. THIS WILL PRODUCE LIKELY TO
CATEGORICAL PRECIPITATION ACROSS THE AREA BETWEEN I-40 AND DEATH
VALLEY...NORTHERN CLARK COUNTY AND THE WESTERN GRAND CANYON.
POP/WX/QPF GRIDS WERE UPDATED ACCORDINGLY. STORM TOTAL QPF AMOUNTS
HAVE BEEN INCREASED TO REFLECT AND AVERAGE BETWEEN 0.25-0.50 INCHES
ACROSS CENTRAL CLARK COUNTY AND THE SPRING MOUNTAINS TODAY.
&&
.AVIATION...FOR MCCARRAN...A STORM OVER SOUTHERN CALIFORNIA WILL
SPREAD RAIN AND LOW CIGS INTO THE LAS VEGAS AREA THE REST OF TODAY
THEN TAPER OFF THIS EVENING. PERIODS OF LIGHT TO MODERATE RAIN CAN
BE EXPECTED THROUGH LATE THIS AFTERNOON AND CIGS WILL LIKELY LOWER
TO AROUND 3K FEET. WINDS WILL REMAIN LIGHT...GENERALLY UNDER 8
KTS THROUGH THE PERIOD. THERE IS A VERY (EMPHASIS ON VERY) REMOTE
CHANCE OF FOG DEVELOPMENT OVERNIGHT IF WETTING RAIN FALLS IN/AROUND
THE TERMINAL TODAY AND SKIES CLEAR OVERNIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...A BROAD AREA OF RAIN WILL CONTINUE TO SPREAD ACROSS
SOUTHEAST CALIFORNIA...FAR SOUTHERN NEVADA AND NORTHWEST ARIZONA
TODAY. CLOUD BASES WILL LOWER TO 3K-7K FEET IN AND NEAR ANY
SHOWERS WITH MOUNTAIN OBSCURATIONS LIKELY. VSBY WILL MAINLY BE VFR
WITH MVFR OR LOWER IN ANY HEAVIER SHOWERS. WINDS WILL REMAIN
GENERALLY LIGHT THROUGH THE PERIOD. PATCHY FOG DEVELOPMENT WILL BE
POSSIBLE TONIGHT IN AREAS THAT SEE WETTING RAIN TODAY AND CLEARING
SKIES TONIGHT.
&&
.PREV DISCUSSION...
223 AM PST SUN JAN 11 2015
.SHORT TERM...TODAY THROUGH MONDAY NIGHT...ACT TWO OF THE THREE
SYSTEM WEEKEND IS UNDERWAY THIS MORNING WITH LIGHT RAIN BEING
REPORTED ACROSS THE WESTERN PORTIONS OF SAN BERNARDINO COUNTY.
AMOUNTS HAVE BEEN LIGHT THUS FAR...STAYING UNDER A TENTH OF AN INCH
AS OF 2 AM. THIS AREA OF PRECIPITATION WILL CONTINUE TO SLOWLY
EXPAND NORTHEAST THIS MORNING BEFORE TRANSLATING EAST ACROSS FAR
SOUTHERN NEVADA AND NORTHWEST ARIZONA THIS AFTERNOON INTO TONIGHT.
THE CORE OF THE TOTAL PRECIPITATION WITH THIS SYSTEM IS EXPECTED TO
FALL ALONG A 120-180 MILE WIDE BAND CENTERED ON A LINE FROM ROUGHLY
BARSTOW TO SEARCHLIGHT TO KINGMAN. IN THIS BAND QPF TOTALS ARE
EXPECTED TO BE BETWEEN 0.10-0.33 INCHES...WITH LIGHTER AMOUNTS
FALLING TO THE NORTH AND SOUTH. LAS VEGAS WILL LIKELY BE SITUATED
ALONG THE NORTHERN FRINGE OF THIS BAND...AND CURRENT ESTIMATES ARE
RAINFALL TOTALS OF A TRACE TO ONE-TENTH OF AN INCH FOR THE VALLEY.
SNOW LEVELS WILL HOVER IN THE 7000-800 FOOT RANGE...AND THUS
SNOWFALL WILL ONLY BE A FACTOR ON THE HIGHEST ROADS...AND EVEN
THERE...SNOWFALL TOTALS SHOULD REMAIN IN THE 1-3 INCH RANGE.
CONDITIONS SHOULD IMPROVE IN MOST AREAS BY THIS EVENING AS DRIER AIR
TRIES TO WORK IN. HOWEVER...THERE IS SLIGHT CONCERN FOR THE
DEVELOPMENT OF PATCHY FOG IN AREAS THAT SEE WETTING RAIN TODAY AND
CLEARING SKIES TONIGHT. DON`T HAVE MUCH CONFIDENCE IN AREAS AT THIS
TIME AND WILL LET SUBSEQUENT SHIFTS TAKE ANOTHER LOOK AT THAT
POTENTIAL FOR TONIGHT.
ANOTHER SYSTEM WILL DIVE SOUTH ACROSS THE SOUTHERN GREAT BASIN
MONDAY. MODELS HAVE SHOWN A SIGNIFICANT EASTWARD TREND IN THIS
SYSTEM OVER THE PAST COUPLE DAYS. AS A RESULT HAVE KNOCKED DOWN
PRECIPITATION CHANCES IN MAY AREAS FOR MONDAY. THE BEST CHANCES WILL
RESIDE OVER EASTERN LINCOLN AS WELL AS CENTRAL AND NORTHERN MOHAVE
COUNTIES. THIS SYSTEM HAS A BIT LESS MOISTURE TO WORK WITH AND SNOW
LEVELS WILL REMAIN GENERALLY ABOVE 6000-6500 FEET...THUS SIGNIFICANT
ACCUMULATING SNOW IS NOT ANTICIPATED. THIS SECOND SYSTEM WILL EXIT
THE AREA MONDAY NIGHT/TUESDAY MORNING.
.LONG TERM...TUESDAY THROUGH SATURDAY...BY TUESDAY MORNING EXPECT
THE TROUGH TO BE AMPLIFYING OVER UTAH...WITH ANY LEFTOVER PRECIP
CHANCES CONFINED TO THE FAR EASTERN FRINGES OF THE CWA. NORTHERLY
FLOW BETWEEN THE TROUGH AND A HIGH AMPLITUDE RIDGE ALONG THE WEST
COAST WILL BRING GUSTY NORTH WINDS TO THE FAVORED AREAS TUESDAY AND
WEDNESDAY...PARTICULARLY THE COLORADO RIVER VALLEY. A WEAK TROUGH
PASSING THROUGH THE PACIFIC NORTHWEST WEDNESDAY INTO THURSDAY
FLATTENS THE RIDGE...LEAVING WEAK WESTERLY FLOW OVER OUR AREA WITH
HIGH HEIGHTS THURSDAY INTO FRIDAY. BY SATURDAY THERE IS MODEL
AGREEMENT ON THE EXISTENCE OF A TROUGH JUST OFF THE WEST COAST...BUT
CONSIDERABLE SPREAD IN ITS EXACT LOCATION AND STRENGTH. THAT WILL BE
SOMETHING TO WATCH IN THE NEAR FUTURE...BUT FOR THE TIME BEING...IT
SHOULD BE DRY THROUGH THE LONG TERM WITH TEMPERATURES RUNNING A FEW
DEGREES ABOVE AVERAGE FOR MID JANUARY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT REQUESTED
BUT SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS
THROUGH MONDAY ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE/AVIATION...ADAIR
SHORT TERM...WOLCOTT
LONG TERM.............MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
316 PM EST SUN JAN 11 2015
.SYNOPSIS...
RAIN TONIGHT. A COLD FRONT MOVE THROUGH ON MONDAY. WEAK WAVE OF LOW
PRESSURE SOUTH POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
REMAIN CONCERNED WITH THE MODEL TRENDS OF GETTING WARMER FOR
TONIGHT IN SOUTHEAST OHIO AND EXTREME NORTHWESTERN WV. MET/MAV AND
LAV GUIDANCE ARE WARMER THAN THE FORECAST...BUT THE HRRR STILL SHOWS
WET BULBING CAUSING ISSUES. WITH SUCH LOW DEW POINTS
CURRENTLY...FROZEN GROUND...AND ADVISORIES ALREADY IN PLACE...WILL
HOLD TIGHT...BUT EVENING SHIFT WILL NEED TO MONITOR THIS CLOSELY.
HRRR AND NAM SOUNDINGS SHOWING POTENTIAL PROBLEMS IN THE SOUTHEAST
UPSLOPE AREAS OF THE NORTHERN MOUNTAINS AS WELL. IN THIS REGION
HOWEVER...LAV GUIDANCE IS SHOWING TEMPERATURE HOOVERING RIGHT AROUND
FREEZING AT LWB...WHICH IS NOT NORMALLY THE COLDEST SPOT. WITH
GROUND FROZEN...THINK THAT POCKETS OF FREEZING RAIN A GOOD BET. WILL
ISSUE A FREEZING RAIN ADVISORY OVERNIGHT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
WITH THE FRONTAL BOUNDARY OFF TO THE SOUTHEAST...WILL BE INFLUENCED
BY A DEVELOPING INVERTED SURFACE TROUGH SETTING UP ALONG THE
MOUNTAINS IN COMBINATION WITH A WEAK MID AND UPPER LEVEL WAVE. THE
RESULT IN THE GRIDS IS NOT TOO MUCH OF A CHANGE IN TERMS OF THE
POPS...KEEPING THE LOW END POPS OVER THE MOUNTAINS BEFORE ENDING
WEDNESDAY. LARGELY BASED THE POPS ON LOW-MID LEVEL LAYER
FRONTOGENESIS WHICH IS ON THE WEAKER SIDE...BUT STILL PRESENT WHEN
LOOKING AT THE NAM.
AN OVERRUNNING SITUATION WILL BE PRESENT WITH THE MOISTURE OVER THE
MOUNTAINS AS THE TROUGH SETS UP AND WILL KEEP IT SIMPLE IN THE
WEATHER GRIDS BY USING THE WARM LAYER ALOFT FROM THE NAM. THIS
CREATES BRIEF SLEET/FREEZING RAIN POTENTIAL BEFORE THE COLD AIR
ADVECTION TAKES HOLD AND TRANSITIONS THE WEATHER TYPE TO ALL SNOW
INTO TUESDAY. ALL THE WHILE...POPS WILL BE LOWERING.
NOT SEEING MUCH OF A TEMPERATURE RECOVERY TUESDAY FROM MONDAY NIGHT
GIVEN THE CLOUD COVER AND WEAK COLD AIR ADVECTION WHICH WILL BE HELD
IN CHECK BY THE MOISTURE PUSH FROM THE AFOREMENTIONED SURFACE TROUGH
FROM THE SOUTH. KEEPING IT COLD ENOUGH IN THE FORECAST FOR OFF AND
ON LIGHT SNOW OVER THE MOUNTAINS AFTER THE FULL PRECIPITATION TYPE
TRANSITION TUESDAY AND TUESDAY NIGHT...WITH SOME LOCATIONS CLIMBING
ABOVE FREEZING WEDNESDAY AS 850MB TEMPERATURES MODIFY SLIGHTLY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
COLDER AIR SWEEPS IN FOR A SEASONABLY COOL EXTENDED. EXPECTING A
MAINLY DRY EXTENDED IS IN THE CARDS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
CLOUDS WILL GRADUALLY BE LOWERING WITH PRECIPITATION MOVING IN
TONIGHT. THE PRECIPITATION WILL BE RAIN FOR MOST OF THE REGION...BUT
SOME SLEET OR FREEZING RAIN IS POSSIBLE IN THE SOUTHEAST UPSLOPE
AREAS OF POCAHONTAS COUNTY...AND CENTRAL OHIO AND EXTREME
NORTHWESTERN WV. A COLD FRONT WILL PUSH THROUGH ON MONDAY...WITH
MORE RESTRICTIONS IN CEILINGS AND PRECIPITATION POSSIBLE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: HIGH THIS AFTERNOON...THEN MEDIUM.
ALTERNATE SCENARIO: TIMING OF LOWERING CEILINGS AND VISIBILITY
RESTRICTIONS COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05
06 07 EST 1HRLY 15 16 17 18 19 20 21 22 23
00 01 02 CRW CONSISTENCY H H H H H H H
H H M M M HTS CONSISTENCY H H H H H H
H H H M H H BKW CONSISTENCY H H H H H
H H H H M M H EKN CONSISTENCY H H H H
H H H H H H H M PKB CONSISTENCY H H H
H H H H H M M M M CKB CONSISTENCY H H
H H H H H H H H M H
AFTER 18Z MONDAY...
IFR POSSIBLE MONDAY AFTERNOON...AND IN THE MOUNTAINS AND SOUTHERN
COUNTIES MONDAY NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR WVZ046-047.
FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR WVZ009>011.
OH...WINTER WEATHER ADVISORY UNTIL 9 AM EST MONDAY FOR OHZ066-067.
FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR OHZ075-076-
083>085.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...RPY
SHORT TERM...26
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
222 PM EST SUN JAN 11 2015
.SYNOPSIS...
RAIN TONIGHT. A COLD FRONT MOVE THROUGH ON MONDAY. WEAK WAVE OF LOW
PRESSURE SOUTH POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
REMAIN CONCERNED WITH THE MODEL TRENDS OF GETTING WARMER FOR
TONIGHT IN SOUTHEAST OHIO AND EXTREME NORTHWESTERN WV. MET/MAV AND LAV
GUIDANCE ARE WARMER THAN THE FORECAST...BUT THE HRRR STILL SHOWS WET
BULBING CAUSING ISSUES. WITH SUCH LOW DEW POINTS CURRENTLY...FROZEN
GROUND...AND ADVISORIES ALREADY IN PLACE...WILL HOLD TIGHT...BUT
EVENING SHIFT WILL NEED TO MONITOR THIS CLOSELY.
HRRR AND NAM SOUNDINGS SHOWING POTENTIAL PROBLEMS IN THE SOUTHEAST
UPSLOPE AREAS OF THE NORTHERN MOUNTAINS AS WELL. IN THIS REGION
HOWEVER...LAV GUIDANCE IS SHOWING TEMPERATURE HOOVERING RIGHT AROUND
FREEZING AT LWB...WHICH IS NOT NORMALLY THE COLDEST SPOT. WITH
GROUND FROZEN...THINK THAT POCKETS OF FREEZING RAIN A GOOD BET. WILL
ISSUE A FREEZING RAIN ADVISORY OVERNIGHT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
TEMPERATURES ALREADY MAINLY ABOVE FREEZING TO START THE
PERIOD...EXCEPT FOR VERY NW CWA IN PERRY AND MORGAN COUNTY. SO
LINGER WINTER WEATHER ADVISORY THERE UNTIL 9AM FOR FREEZING
RAIN...POSSIBLY MIXED WITH SOME SLEET/SNOW. HAVE HIGH POPS AT THE
START OF THE PERIOD...AS COLD FRONT BEGINS MOVING THROUGH. THAT
FRONT WILL CROSS CWA MONDAY WITH MAINLY RAIN. AS THE COLD AIR WORKS
IN LATER MONDAY AND MONDAY NIGHT...EXPECT A TRANSITION FROM RAIN TO
SLEET TO SNOW. MOISTURE ALREADY BECOMING FAIRLY LIMITED BY THE TIME
COLD ENOUGH AIR WORKS IN FOR SNOW...SO ONLY HAVE LIGHT ACCUMULATIONS
AND MAINLY IN THE NORTHERN MOUNTAINOUS COUNTIES.
A WAVE RIDES UP THE FRONT TUESDAY...SO HANG ONTO POPS ACROSS THE
EAST INTO TUESDAY NIGHT...THEN GRADUALLY DECREASE. DO HAVE HIGHER
POPS FOR THIS THAN PREVIOUS FORECAST...BUT STILL ONLY GETTING UP TO
AROUND A 40 PERCENT CHANCE AS THE MAIN ACTIVITY LOOKS TO STAY SE OF
CWA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
COLDER AIR SWEEPS IN FOR A SEASONABLY COOL EXTENDED. AFTER THE
SYSTEM MONDAY/EARLY TUESDAY...APPEARS A MAINLY DRY EXTENDED IS IN
THE CARDS. THE MODELS CONTINUE E WITH SYSTEM MIDWEEK. DID LEAVE SOME
SMALL POPS ACROSS E HALF OF CWA FOR MIDWEEK AS THIS SYSTEM MAY TREND
A BIT W WITH TIME.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
CLOUDS WILL GRADUALLY BE LOWERING WITH PRECIPITATION MOVING IN
TONIGHT. THE PRECIPITATION WILL BE RAIN FOR MOST OF THE REGION...BUT
SOME SLEET OR FREEZING RAIN IS POSSIBLE IN THE SOUTHEAST UPSLOPE
AREAS OF POCAHONTAS COUNTY...AND CENTRAL OHIO AND EXTREME
NORTHWESTERN WV. A COLD FRONT WILL PUSH THROUGH ON MONDAY...WITH
MORE RESTRICTIONS IN CEILINGS AND PRECIPITATION POSSIBLE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: HIGH THIS AFTERNOON...THEN MEDIUM.
ALTERNATE SCENARIO: TIMING OF LOWERING CEILINGS AND VISIBILITY
RESTRICTIONS COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H M
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
IFR POSSIBLE MONDAY AFTERNOON...AND IN THE MOUNTAINS AND SOUTHERN
COUNTIES MONDAY NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 10 PM THIS EVENING TO 9 AM EST
MONDAY FOR WVZ046-047.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR WVZ009>011.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM EST
MONDAY FOR OHZ066-067.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR OHZ075-076-083>085.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...RPY
SHORT TERM...MZ
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1213 PM EST SUN JAN 11 2015
.SYNOPSIS...
MOISTURE/CLOUDS INCREASES TODAY...BUT NOT QUITE AS COLD IN AFTERNOON.
COLD FRONT SAGS SOUTH MONDAY. WEAK WAVE OF LOW PRESSURE SOUTH
POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
BASED ON LATEST MODELS AND SATELLITE TRENDS...WILL INCREASE CLOUD
COVER FOR THIS AFTERNOON.
AM A BIT CONCERNED WITH THE MODEL TRENDS OF GETTING WARMER FOR THIS
AFTERNOON AND TONIGHT IN SOUTHEAST OHIO. MET/MAV AND LAV GUIDANCE
ARE MUCH WARMER THAN FORECAST...BUT THE HRRR STILL SHOWS WET BULBING
CAUSING ISSUES. WILL HOLD TIGHT FOR THE MORNING UPDATE...BUT WILL
HAVE TO TAKE A GOOD HARD LOOK FOR THE AFTERNOON PACKAGE.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY/...
TEMPERATURES ALREADY MAINLY ABOVE FREEZING TO START THE
PERIOD...EXCEPT FOR VERY NW CWA IN PERRY AND MORGAN COUNTY. SO
LINGER WINTER WEATHER ADVISORY THERE UNTIL 9AM FOR FREEZING
RAIN...POSSIBLY MIXED WITH SOME SLEET/SNOW. HAVE HIGH POPS AT THE
START OF THE PERIOD...AS COLD FRONT BEGINS MOVING THROUGH. THAT
FRONT WILL CROSS CWA MONDAY WITH MAINLY RAIN. AS THE COLD AIR WORKS
IN LATER MONDAY AND MONDAY NIGHT...EXPECT A TRANSITION FROM RAIN TO
SLEET TO SNOW. MOISTURE ALREADY BECOMING FAIRLY LIMITED BY THE TIME
COLD ENOUGH AIR WORKS IN FOR SNOW...SO ONLY HAVE LIGHT ACCUMULATIONS
AND MAINLY IN THE NORTHERN MOUNTAINOUS COUNTIES.
A WAVE RIDES UP THE FRONT TUESDAY...SO HANG ONTO POPS ACROSS THE
EAST INTO TUESDAY NIGHT...THEN GRADUALLY DECREASE. DO HAVE HIGHER
POPS FOR THIS THAN PREVIOUS FORECAST...BUT STILL ONLY GETTING UP TO
AROUND A 40 PERCENT CHANCE AS THE MAIN ACTIVITY LOOKS TO STAY SE OF
CWA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
COLDER AIR SWEEPS IN FOR A SEASONABLY COOL EXTENDED. AFTER THE
SYSTEM MONDAY/EARLY TUESDAY...APPEARS A MAINLY DRY EXTENDED IS IN
THE CARDS. THE MODELS CONTINUE E WITH SYSTEM MIDWEEK. DID LEAVE SOME
SMALL POPS ACROSS E HALF OF CWA FOR MIDWEEK AS THIS SYSTEM MAY TREND
A BIT W WITH TIME.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
CLOUDS WILL GRADUALLY BE LOWERING WITH PRECIPITATION MOVING IN
TONIGHT. THE PRECIPITATION WILL BE RAIN FOR MOST OF THE REGION...BUT
SOME SLEET OR FREEZING RAIN IS POSSIBLE IN THE SOUTHEAST UPSLOPE
AREAS OF POCAHONTAS COUNTY...AND CENTRAL OHIO AND EXTREME
NORTHWESTERN WV. A COLD FRONT WILL PUSH THROUGH ON MONDAY...WITH
MORE RESTRICTIONS IN CEILINGS AND PRECIPITATION POSSIBLE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: HIGH THIS AFTERNOON...THEN MEDIUM.
ALTERNATE SCENARIO: TIMING OF LOWERING CEILINGS AND VISIBILITY
RESTRICTIONS COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H M
BKW CONSISTENCY H H H H H H H H H H H M
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
IFR POSSIBLE MONDAY AFTERNOON...AND IN THE MOUNTAINS AND SOUTHERN
COUNTIES MONDAY NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR WVZ009>011.
OH...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM EST
MONDAY FOR OHZ066-067.
FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST
MONDAY FOR OHZ075-076-083>085.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...RPY
SHORT TERM...MZ
LONG TERM...30
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1035 AM MST SUN JAN 11 2015
.UPDATE...
ISSUED AT 1015 AM MST SUN JAN 11 2015
ANOTHER INTERESTING AND CHALLENGING AFTERNOON FORECAST TODAY WITH
THE MODIFIED ARCTIC AIR INTRUSION ALONG WITH SNOW CHANCES.
WATCHING THE COLD AIR ADVECTION ACROSS NORTHEAST WYOMING AND
WESTERN SOUTH DAKOTA...AND OUR CURRENT TEMPERATURE TRENDS...
HAVE MODIFIED OUR MAXIMUM TEMPERATURES SLIGHTLY...AS WELL AS
MASSAGED THE GRIDDED FORECASTS TO SHOW FALLING TEMPERATURES BY
SUPPER TIME AS THE NAM TEMPS HAVE A DECENT HANDLE ON THIS.
WEAK SHORTWAVE TROUGH ALOFT AND DECENT UPWARD VERTICAL MOTION
MOVE ACROSS OUR COUNTIES THIS AFTERNOON WITH MESOSCALE LIFT AND
UPSLOPE LIFT ALONG AND EAST OF THE MOUNTAINS AIDING IN INCREASING
AREAL COVERAGE OF SNOW...SO HAVE ADJUSTED POPS TO ACCOUNT FOR
THIS...ESPECIALLY WITH THE 12Z NAM SHOWING OUR LOW AND MID LEVELS
SATURATING NICELY THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 320 AM MST SUN JAN 11 2015
CURRENT IR SATELLITE LOOP AND SURFACE OBS ACROSS THE REGION SHOW
YET ANOTHER REINFORCING SHOT OF COLD ARCTIC AIR ACROSS
MONTANA...PUSHING SOUTHWARD EARLY THIS MORNING. THE LEADING EDGE
OF THE FRONT APPEARS TO HAVE JUST PUSHED INTO NORTHERN
WYOMING...WITH WINDS SHIFTING INTO THE NORTH AT GILLETTE AND
SHERIDAN AND INCREASING BAROMETRIC PRESSURE. THANKFULLY...MODELS
SHOW THE BULK OF THE COLDEST AIR STAYING EAST OF THE REGION AS
SOUTHEAST WYOMING AND WESTERN NEBRASKA AS THE AREA GETS BRUSHED BY
THE ARCTIC DOME OVER THE DAKOTAS BY THIS TIME TOMORROW MORNING.
HOWEVER...WE EXPECT MORE SNOWFALL IN THIS EVENT COMPARED TO THE
PREVIOUS ARCTIC FRONTAL PASSAGES IN THE LAST WEEK AS FRONTOGENESIS
COMBINES WITH UPSLOPE FLOW AND MID TO UPPER LEVEL DYNAMICS FROM A
SERIES OF UPPER LEVEL DISTURBANCES MOVING ACROSS THE GREAT BASIN
REGION AND INTO THE CENTRAL ROCKY MOUNTAINS THROUGH LATE MONDAY
NIGHT.
THE ARCTIC FRONT AND ASSOCIATED COLDER AIRMASS WILL BEGIN TO PUSH
INTO THE REGION LATE THIS MORNING...AND THEN ACROSS THE REST OF
THE HIGH PLAINS INTO COLORADO THROUGH THIS AFTERNOON. HIGH
TEMPERATURES WILL OCCUR SOMETIME THIS MORNING BEFORE TEMPERATURES
LOWER INTO THE TEENS AND 20S ACROSS THE HIGH PLAINS LATE THIS
AFTERNOON. THE FRONT WILL THEN STALL NEAR OR JUST WEST OF THE
LARAMIE RANGE...CREATING A NATURAL CONVERGENCE BOUNDARY WITH EAST
TO SOUTHEAST WINDS ACROSS THE HIGH PLAINS AND WEST TO SOUTHWEST
WINDS WEST OF THE FRONT. IN ADDITION...SOME WARM AIR ADVECTION
ALOFT AROUND 700MB IS EXPECTED AHEAD OF EACH UPPER LEVEL
DISTURBANCE AS THEY MOVE TOWARDS THE FORECAST AREA. THIS WILL
CREATE LIFT AND WILL ACT LIKE A WARM FRONTAL BOUNDARY WITH
RELATIVELY WARM AND MOIST AIR OVERRUNNING COLD AIR NEAR THE
SURFACE. EXPECT A HIGH POP/LOW QPF EVENT BEGINNING LATE TODAY
THROUGH TONIGHT. SNOWFALL WILL REMAIN NEAR THE MOUNTAINS THROUGH
MOST OF TODAY...BUT WHEN THE ARCTIC FRONT MOVES SOUTH AND WEST
ACROSS THE AREA...SNOWFALL WILL THEN DEVELOP FURTHER EAST ACROSS
EXTREME SOUTHEAST WYOMING AND WESTERN NEBRASKA. MAINLY EXPECT
LIGHT SNOW INTENSITY...WITH PERHAPS SOME BANDS OF MODERATE SNOW
ALONG THE LARAMIE RANGE AND IN THE MOUNTAINS. 3 TO 6 INCHES OF
SNOW APPEARS TO BE A GOOD BET FOR THE MOUNTAINS THROUGH
TONIGHT...WITH 1 TO 3 INCHES FOR THE HIGH VALLEYS AND HIGH PLAINS.
PRETTY SURE A FEW LOCATIONS OUTSIDE THE MOUNTAINS WILL RECEIVE 4
OR 5 INCHES...BUT THESE WILL BE TOO ISOLATED AND DIFFICULT TO PIN
DOWN FOR A WINTER WEATHER ADVISORY AT THIS TIME. WITH WINDS
SHIFTING INTO THE SOUTH BY EARLY MONDAY MORNING...THE POTENTIAL
FOR DENSE FOG IS HIGH OVER THE CHEYENNE RIDGE AND SOUTHERN LARAMIE
RANGE DUE TO UPSLOPE FLOW FROM THE OPPOSITE DIRECTION. THERE IS A
SMALL CHANCE AT SOME FREEZING DRIZZLE...BUT CURRENT MODEL
SOUNDINGS DO NOT SUPPORT A WIDESPREAD EVENT FOR MORE THAN AN HOUR
OR TWO.
EXPECT A BRIEF BREAK ON MONDAY AS THE LOW AND UPPER LEVELS DRY OUT
A BIT...BUT MAY STILL HAVE SOME LINGERING FOG WITH SOUTHERLY WINDS
THROUGH THE DAY ACROSS THE CHEYENNE RIDGE. MODELS THEN SHOW THE
THIRD UPPER LEVEL DISTURBANCE PUSHING ONSHORE AND DEVELOPING A
MORE POTENT UPPER LEVEL TROUGH ACROSS THE EASTERN GREAT BASIN
REGION. THIS SYSTEM WILL BRING A HIGHER CHANCE OF MODERATE TO
HEAVY SNOW TO THE WASATCH AND WEST OF THE CONTINENTAL DIVIDE.
MODELS HAVE CONTINUED TRENDING THIS SYSTEM SOUTH OF THE FORECAST
AREA...AS IT DIGS SOUTHEAST INTO THE FOUR CORNERS REGION AND
CONTINUES MOVING SOUTHEAST OR EAST. HOWEVER...WILL HAVE TO MONITOR
THE EVOLUTION OF THIS SYSTEM AS IT PUSHES ONSHORE SINCE THE 00Z
AND 06Z NAM SHOW THE TROUGH BECOMING A CLOSED LOW AS IT DRIFTS
EAST OVER COLORADO. THIS SOLUTION WOULD TYPICALLY RESULT IN MORE
SNOWFALL ACROSS SOUTHEAST WYOMING. KEPT POP FOR THE LOWER
ELEVATIONS OF SOUTHEAST WYOMING BETWEEN 15 TO 25 PERCENT FOR
NOW...WITH VALUES BELOW 10 PERCENT EAST OF I25. TEMPERATURES WILL
BE BELOW NORMAL FOR BOTH MONDAY AND TUESDAY...WITH HIGHS IN THE
20S TO LOW 30S...WARMEST WEST OF THE LARAMIE RANGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 219 AM MST SUN JAN 11 2015
00Z MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT WITH A MEAN RIDGE
WEST OF THE ROCKIES AND A TROUGH FROM THE GREAT PLAINS EASTWARD
MIDWEEK. THE RIDGE TRANSLATES EAST AND DEAMPLIFIES AS SHORTWAVE
ENERGY MOVES FROM THE PACIFIC NORTHWEST ACROSS ID/MT INTO WY/NE
THURSDAY THROUGH FRIDAY. NOT EXPECTING ANY PRECIPITATION AS MOISTURE
WILL BE LIMITED. WILL SEE AN INCREASE IN WESTERLY WINDS FRIDAY WITH
GUSTS OF 30 TO 40 KT POSSIBLE OVER THE NORTHERN LARAMIE RANGE. HIGH
TEMPERATURES WILL MODERATE FROM THE 20S AND 30S WEDNESDAY TO THE
30S AND 40S THURSDAY AND FRIDAY. THE MILD TEMPERATURES WILL LIKELY
PERSIST INTO NEXT WEEKEND AS A MORE ZONAL PATTERN ALOFT DEVELOPS
WITH BREEZY TO WINDY WESTERLY WINDS CONTINUING. THERE ARE INDICATIONS
THAT PACIFIC MOISTURE WILL SPREAD EAST INTO SOUTH CENTRAL WY SUNDAY
WITH LIGHT SNOW POSSIBLE ACROSS SOUTHERN CARBON COUNTY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 219 AM MST SUN JAN 11 2015
LATEST HRRR MODEL DATA DEPICTS VFR CONDITIONS PREVAILING EAST OF
THE LARAMIE RANGE THROUGH MIDDAY FOLLOWED BY DETERIORATING CIGS
AND VSBYS THIS AFTERNOON AS A COLD FRONT PUSHES SOUTH ACROSS THE
FORECAST AREA. WEST OF THE LARAMIE RANGE...MVFR TO IFR CONDITIONS
WILL DEVELOP IN LOW CIGS AND LIGHT SNOW. THE MOUNTAINS WILL BE
OBSCURED THROUGH THE PERIOD. WINDS WILL SHIFT FROM SOUTHWESTERLY
TO NORTHERLY WITH FROPA. SPEEDS WILL AVERAGE LESS THAN 15 KT.
&&
.FIRE WEATHER...
ISSUED AT 159 AM MST SUN JAN 11 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEK WITH COOL
TEMPERATURES...UNSETTLED CONDITIONS AT TIMES...AND HIGH HUMIDITIES
CONTINUING OVER THE AREA. A WARMING TREND IS EXPECTED BY LATE THIS
WEEK...BUT DAYTIME HUMIDITIES WILL REMAIN OVER 40 PERCENT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...TJT
LONG TERM...MJ
AVIATION...MJ
FIRE WEATHER...TJT