Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/07/16
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
900 AM MST TUE JAN 5 2016
.SYNOPSIS...
ANTICIPATE SCATTERED SHOWERS THIS MORNING BEFORE MORE NUMEROUS
SHOWERS DEVELOP LATER TODAY. WITH THE NEXT WEATHER SYSTEM IN THE
SERIES. PRECIPITATION CHANCES CONTINUE THROUGH FRIDAY. BELOW NORMAL
HIGH TEMPERATURES WILL CONTINUE AS WELL. CONDITIONS WILL START TO
DRY OUT FOR THE COMING WEEKEND...BUT TEMPERATURES WILL REMAIN BELOW
SEASONAL NORMALS.
&&
.DISCUSSION...
NOT A WHOLE LOT OF RAIN ACROSS THE AREA AT THE MOMENT BUT LINGERING
MOISTURE RESULTED IN QUITE A BIT OF LOW CLOUDS AND EVEN SOME FOG
ACROSS PARTS OF THE AREA /MAINLY SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA/. WITH HIGH CLOUDS APPROACHING FROM THE WEST...FOG HAS
DISSIPATED ACROSS THESE AREAS AND THE DENSE FOG ADVISORY HAS BEEN
ALLOWED TO EXPIRE.
A QUICK LOOK AT THE AVAILABLE 12Z MODELS AND 09Z SREF INDICATES MOST
OF THE DAY SHOULD BE DRY ACROSS THE LOWER DESERTS...ONLY TO BE
REPLACED BY SHOWERS LATE THIS AFTERNOON/EVENING AS THE SECOND OF FOUR
TROUGHS APPROACHES THE AREA. OPERATIONAL MODELS AND ENSEMBLES STILL
POINTING TOWARD SHOWERS DEVELOPING ACROSS EL CENTRO/BLYTHE/YUMA
AROUND 00Z AND IN THE PHOENIX AREA CLOSER TO 06Z. HRRR RUNS ARE ALSO
INDICATING SIMILAR TIMING. IF ANYTHING THIS MAY BE TRENDING SLIGHTLY
FASTER THAN PREVIOUS RUNS INDICATED AND THE PREVIOUS SHIFTS CORRECTLY
ACCOUNTED FOR THIS. ONLY MAKING MINOR ADJUSTMENTS TO THE INHERITED
POPS AND WX GRIDS BASED ON OBSERVATIONAL TRENDS. OTHERWISE THE
FORECAST IS IN GOOD SHAPE.
&&
.PREVIOUS DISCUSSION...
TODAY THROUGH FRIDAY...
THE NEXT SYSTEM IS ALREADY MOVING INTO CALIFORNIA. LIFTING
MECHANISMS WITH THIS SYSTEM LOOK TO BE SIMILAR TO MONDAYS WITH SOME
LOWER LEVEL CONVERGENCE...UPPER LEVEL DIVERGENCE...AND A DIV Q
BULLSEYE. NAM NOT AS ROBUST AS THE GFS IS IN THOSE FIELDS. LATEST
MODELS INDICATE ITS ARRIVAL AND DEPARTURE WILL BE A BIT FASTER THAN
WAS DEPICTED IN PREVIOUS FORECAST PACKAGE. MADE ADJUSTMENTS TO THE
POPS ACCORDINGLY. SREF INDICATES SOME VERY MODEST CAPE FOR TODAY AND
TONIGHT. SPC HAS GENERAL THUNDER IN THE DAY 1 OUTLOOK FOR OUR WESTERN
AREAS...THOUGH SREF CAPE IS A BIT EAST OF THERE. TAKING THESE FACTORS
INTO ACCOUNT ALONG WITH MODEL LIFTED INDICES...ADDED SLIGHT CHANCE OF
THUNDERSTORMS FOR THIS AFTERNOON AND EVENING. OVERALL...QPF IS
LOOKING HIGHER WITH THIS SYSTEM THAN WHAT WE HAD WITH MONDAYS.
ADVISORY TYPE IMPACTS ARE QUITE POSSIBLE. SNOW LEVELS GENERALLY
REMAIN NEAR OR ABOVE 6000 FEET.
NEXT SYSTEM HAS TWO MAIN WAVES WITH IT. THE FIRST ONE MOVES IN WEDNESDAY
NIGHT AND EXITS OUR EASTERN AREAS THURSDAY EVENING. THE SECOND ONE IS
RIGHT ON ITS HEELS FOR FRIDAY. THE SECOND ONE HAS LESS LIFT GOING FOR
IT. SNOW LEVELS DROP THURSDAY AND FRIDAY...DOWN TO ABOUT 4000-4500 FEET
FRIDAY MORNING AND NOT CHANGING MUCH DURING THE DAY FRIDAY.
ADDITIONAL PRECIP FOR REST OF THIS WEEK...IS 1.5-2.5 INCHES OVER THE
FOOTHILLS AND HIGHER TERRAIN...1.0-1.5 INCHES OVER THE PHOENIX
AREA...AND 0.25-0.75 OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.
SATURDAY THROUGH MONDAY...
NORTHWEST FLOW AND WEAK DRY ADVECTION ACROSS THE AREA LOOKS LIKELY
THROUGH THE WEEKEND INTO NEXT WEEK...ALTHOUGH THERE`S SOME HINT AT A
DRY TROUGH MOVING THROUGH THE AREA ON SUNDAY /SOME INCREASED CLOUD
COVER AND THAT`S ABOUT IT/. SHOULD THIS TROUGH NOT DEVELOP...WE`LL NEED
TO KEEP AN EYE ON FOG POTENTIAL THIS WEEKEND /SATURDAY OR SUNDAY/ IF
THE BL DOESN`T SUFFICIENTLY DRY OUT. THE PATTERN IS CERTAINLY
CONDUCIVE FOR WIDESPREAD FOG DEVELOPMENT ACROSS THE AREA AND IT
WARRANTS MENTIONING. FAIRLY GOOD AGREEMENT OF STRONG UPPER RIDGING
ACROSS THE AREA BY MONDAY OF NEXT WEEK WITH TEMPERATURES RETURNING TO
EARLY JANUARY NORMALS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
DESPITE WEAK AND FLAT UPPER RIDGING NOW MOVING INTO THE
DESERTS...CONSIDERABLE LOW LEVEL MOISTURE REMAINS IN PLACE AND THERE
WILL BE LINGERING ISOLD/SCT LIGHT SHOWERS THROUGH MID MORNING WITH
WIDESPREAD CIGS BELOW 5K FEET...WITH SCATTERED CIGS TO AROUND 2K
FEET THRU 16Z OR SO. AFTER THAT CIGS SHOULD GENLY STAY IN THE 4-6K
BALLPARK WITH FEW-SCT LOWER DECKS AT TIMES. ANOTHER WET WEATHER
SYSTEM WILL MOVE IN FROM THE WEST TONIGHT LEADING TO WIDESPREAD
SHOWERS STARTING BY AROUND 03Z...CAUSING AREAS OF CIGS DOWN TO 2K
FEET WITH THE POTENTIAL FOR SOME VSBY RESTRICTIONS BELOW 5SM IN
FOG/MIST OR EVEN MODERATE TO HEAVY RAIN. WINDS AGAIN WILL FAVOR THE
EAST TO SOUTHEAST FOR THE NEXT 24 HOURS AT THE TAF SITES.
FINALLY...WE CANNOT RULE OUT AN ISOLATE THUNDERSTORM DEVELOPING
TONIGHT AS THE SYSTEM PASSES THROUGH BUT CONFIDENCE WAY TOO LOW TO
MENTION THUNDER IN ANY OF THE TAFS AT THIS TIME.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
THE THREAT FOR PRECIP THIS MORNING IS FAIRLY LOW BUT CONSIDERABLE
LOW CLOUDS WILL REMAIN IN PLACE WITH WIDESPREAD CIGS 4-6 FEET
EXPECTED ALONG WITH THE OCCASIONAL CIG DOWN TO 3K FEET OR LOWER SUCH
AS AT KBLH. THEN...ANOTHER WET PACIFIC LOW WILL MOVE INTO THE AREA
FROM THE WEST THIS AFTERNOON LEADING TO SCATTERED TO NUMEROUS
LIGHT/MODERATE SHOWERS AND A RETURN TO VERY LOW CIGS ALONG WITH SOME
VSBY RESTRICTIONS. SHOWERS WILL DISSIPATE WITH PARTIAL CLEARING FROM
THE WEST STARTING BY AROUND 03Z WITH MAINLY SCATTERED DECKS EXPECTED
AFTER MIDNIGHT. EXPECT MAINLY LIGHT VARIABLE TO SOUTHEAST WINDS
TODAY BECOMING A BIT STRONGER FROM THE SOUTHWEST TO WEST OVERNIGHT
TONIGHT.
FINALLY...WE CANNOT RULE OUT AN ISOLATED THUNDERSTORM MIXED IN
MAINLY DURING THE AFTERNOON HOURS BUT CONFIDENCE IS TOO LOW TO
MENTION IN THE TAFS AT THIS TIME.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER... THURSDAY THROUGH MONDAY...A COUPLE MORE WEATHER
DISTURBANCES WILL MOVE THROUGH THE DISTRICTS IN CLOSE SUCCESSION
DURING THE LATTER HALF OF THE WORK WEEK...MAINLY EAST OF THE LOWER
COLORADO RIVER VALLEY. RAIN CHANCES TAPER OFF FOR THE WEEKEND AND
INTO EARLY NEXT WEEK. HUMIDITY WILL BE MUCH ABOVE AVERAGE WITH
MINIMUM VALUES NEAR AND ABOVE 50 PERCENT MOST DAYS ON THE LOWER
DESERTS AND MAX VALUES NEAR AND ABOVE 80 PERCENT MUCH OF THE TIME.
VALUES TREND DOWN FROM WEST TO EAST SATURDAY INTO MONDAY BUT
GENERALLY REMAIN ABOVE 30 PERCENT MOST PLACES. EXPECT WELL BELOW
NORMAL HIGH TEMPERATURES THROUGH FRIDAY WITH DESERT HIGHS IN THE
50S...AND SLIGHT WARMING OVER THE WEEKEND AS HUMIDITIES START TO
FALL OFF. DESPITE THE ACTIVE WEATHER PATTERN NO STRONG WIND EVENTS
ARE EXPECTED BUT JUST BREEZY AT TIMES...MAINLY ON THURSDAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/AJ
AVIATION...CB
FIRE WEATHER...AJ/CB
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
550 AM MST TUE JAN 5 2016
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.
&&
.SYNOPSIS...
ANTICIPATE SCATTERED SHOWERS THIS MORNING BEFORE MORE NUMEROUS
SHOWERS DEVELOP LATER TODAY. WITH THE NEXT WEATHER SYSTEM IN THE
SERIES. PRECIPITATION CHANCES CONTINUE THROUGH FRIDAY. BELOW NORMAL
HIGH TEMPERATURES WILL CONTINUE AS WELL. CONDITIONS WILL START TO
DRY OUT FOR THE COMING WEEKEND...BUT TEMPERATURES WILL REMAIN BELOW
SEASONAL NORMALS.
&&
.DISCUSSION...
TODAY THROUGH FRIDAY...
BAND OF PRECIP THAT BROUGHT MUCH OF YESTERDAYS RAINFALL TO SOUTH-
CENTRAL ARIZONA HAS BEEN SLOWLY DISSIPATING. HOWEVER...A TRAILING
IMPULSE IS KEEPING SOME ISOLATED VERY LIGHT SHOWERS GOING. HRRR KEEPS
THESE GOING AND EXPANDS THE AREA TO THE LOWER COLORADO RIVER VALLEY
BEFORE SUNRISE. THE NEXT SYSTEM IS ALREADY MOVING INTO CALIFORNIA.
LIFTING MECHANISMS WITH THIS SYSTEM LOOK TO BE SIMILAR TO MONDAYS
WITH SOME LOWER LEVEL CONVERGENCE...UPPER LEVEL DIVERGENCE...AND A
DIV Q BULLSEYE. NAM NOT AS ROBUST AS THE GFS IS IN THOSE FIELDS.
LATEST MODELS INDICATE ITS ARRIVAL AND DEPARTURE WILL BE A BIT FASTER
THAN WAS DEPICTED IN PREVIOUS FORECAST PACKAGE. MADE ADJUSTMENTS TO
THE POPS ACCORDINGLY. SREF INDICATES SOME VERY MODEST CAPE FOR TODAY
AND TONIGHT. SPC HAS GENERAL THUNDER IN THE DAY 1 OUTLOOK FOR OUR
WESTERN AREAS...THOUGH SREF CAPE IS A BIT EAST OF THERE. TAKING THESE
FACTORS INTO ACCOUNT ALONG WITH MODEL LIFTED INDICES...ADDED SLIGHT
CHANCE OF THUNDERSTORMS FOR THIS AFTERNOON AND EVENING. OVERALL...QPF
IS LOOKING HIGHER WITH THIS SYSTEM THAN WHAT WE HAD WITH MONDAYS.
ADVISORY TYPE IMPACTS ARE QUITE POSSIBLE. SNOW LEVELS GENERALLY
REMAIN NEAR OR ABOVE 6000 FEET.
NEXT SYSTEM HAS TWO MAIN WAVES WITH IT. THE FIRST ONE MOVES IN WEDNESDAY
NIGHT AND EXITS OUR EASTERN AREAS THURSDAY EVENING. THE SECOND ONE IS
RIGHT ON ITS HEELS FOR FRIDAY. THE SECOND ONE HAS LESS LIFT GOING FOR
IT. SNOW LEVELS DROP THURSDAY AND FRIDAY...DOWN TO ABOUT 4000-4500 FEET
FRIDAY MORNING AND NOT CHANGING MUCH DURING THE DAY FRIDAY.
ADDITIONAL PRECIP FOR REST OF THIS WEEK...IS 1.5-2.5 INCHES OVER THE
FOOTHILLS AND HIGHER TERRAIN...1.0-1.5 INCHES OVER THE PHOENIX
AREA...AND 0.25-0.75 OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.
SATURDAY THROUGH MONDAY...
NORTHWEST FLOW AND WEAK DRY ADVECTION ACROSS THE AREA LOOKS LIKELY
THROUGH THE WEEKEND INTO NEXT WEEK...ALTHOUGH THERE`S SOME HINT AT A
DRY TROUGH MOVING THROUGH THE AREA ON SUNDAY /SOME INCREASED CLOUD
COVER AND THAT`S ABOUT IT/. SHOULD THIS TROUGH NOT DEVELOP...WE`LL NEED
TO KEEP AN EYE ON FOG POTENTIAL THIS WEEKEND /SATURDAY OR SUNDAY/ IF
THE BL DOESN`T SUFFICIENTLY DRY OUT. THE PATTERN IS CERTAINLY
CONDUCIVE FOR WIDESPREAD FOG DEVELOPMENT ACROSS THE AREA AND IT
WARRANTS MENTIONING. FAIRLY GOOD AGREEMENT OF STRONG UPPER RIDGING
ACROSS THE AREA BY MONDAY OF NEXT WEEK WITH TEMPERATURES RETURNING TO
EARLY JANUARY NORMALS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
DESPITE WEAK AND FLAT UPPER RIDGING NOW MOVING INTO THE
DESERTS...CONSIDERABLE LOW LEVEL MOISTURE REMAINS IN PLACE AND THERE
WILL BE LINGERING ISOLD/SCT LIGHT SHOWERS THROUGH MID MORNING WITH
WIDESPREAD CIGS BELOW 5K FEET...WITH SCATTERED CIGS TO AROUND 2K
FEET THRU 16Z OR SO. AFTER THAT CIGS SHOULD GENLY STAY IN THE 4-6K
BALLPARK WITH FEW-SCT LOWER DECKS AT TIMES. ANOTHER WET WEATHER
SYSTEM WILL MOVE IN FROM THE WEST TONIGHT LEADING TO WIDESPREAD
SHOWERS STARTING BY AROUND 03Z...CAUSING AREAS OF CIGS DOWN TO 2K
FEET WITH THE POTENTIAL FOR SOME VSBY RESTRICTIONS BELOW 5SM IN
FOG/MIST OR EVEN MODERATE TO HEAVY RAIN. WINDS AGAIN WILL FAVOR THE
EAST TO SOUTHEAST FOR THE NEXT 24 HOURS AT THE TAF SITES.
FINALLY...WE CANNOT RULE OUT AN ISOLATE THUNDERSTORM DEVELOPING
TONIGHT AS THE SYSTEM PASSES THROUGH BUT CONFIDENCE WAY TOO LOW TO
MENTION THUNDER IN ANY OF THE TAFS AT THIS TIME.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
THE THREAT FOR PRECIP THIS MORNING IS FAIRLY LOW BUT CONSIDERABLE
LOW CLOUDS WILL REMAIN IN PLACE WITH WIDESPREAD CIGS 4-6 FEET
EXPECTED ALONG WITH THE OCCASIONAL CIG DOWN TO 3K FEET OR LOWER SUCH
AS AT KBLH. THEN...ANOTHER WET PACIFIC LOW WILL MOVE INTO THE AREA
FROM THE WEST THIS AFTERNOON LEADING TO SCATTERED TO NUMEROUS
LIGHT/MODERATE SHOWERS AND A RETURN TO VERY LOW CIGS ALONG WITH SOME
VSBY RESTRICTIONS. SHOWERS WILL DISSIPATE WITH PARTIAL CLEARING FROM
THE WEST STARTING BY AROUND 03Z WITH MAINLY SCATTERED DECKS EXPECTED
AFTER MIDNIGHT. EXPECT MAINLY LIGHT VARIABLE TO SOUTHEAST WINDS
TODAY BECOMING A BIT STRONGER FROM THE SOUTHWEST TO WEST OVERNIGHT
TONIGHT.
FINALLY...WE CANNOT RULE OUT AN ISOLATED THUNDERSTORM MIXED IN
MAINLY DURING THE AFTERNOON HOURS BUT CONFIDENCE IS TOO LOW TO
MENTION IN THE TAFS AT THIS TIME.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER... THURSDAY THROUGH MONDAY...A COUPLE MORE WEATHER
DISTURBANCES WILL MOVE THROUGH THE DISTRICTS IN CLOSE SUCCESSION
DURING THE LATTER HALF OF THE WORK WEEK...MAINLY EAST OF THE LOWER
COLORADO RIVER VALLEY. RAIN CHANCES TAPER OFF FOR THE WEEKEND AND
INTO EARLY NEXT WEEK. HUMIDITY WILL BE MUCH ABOVE AVERAGE WITH
MINIMUM VALUES NEAR AND ABOVE 50 PERCENT MOST DAYS ON THE LOWER
DESERTS AND MAX VALUES NEAR AND ABOVE 80 PERCENT MUCH OF THE TIME.
VALUES TREND DOWN FROM WEST TO EAST SATURDAY INTO MONDAY BUT
GENERALLY REMAIN ABOVE 30 PERCENT MOST PLACES. EXPECT WELL BELOW
NORMAL HIGH TEMPERATURES THROUGH FRIDAY WITH DESERT HIGHS IN THE
50S...AND SLIGHT WARMING OVER THE WEEKEND AS HUMIDITIES START TO
FALL OFF. DESPITE THE ACTIVE WEATHER PATTERN NO STRONG WIND EVENTS
ARE EXPECTED BUT JUST BREEZY AT TIMES...MAINLY ON THURSDAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ/LEINS
AVIATION...CB
FIRE WEATHER...AJ/CB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
343 AM MST TUE JAN 5 2016
.SYNOPSIS...
ANTICIPATE SCATTERED SHOWERS THIS MORNING BEFORE MORE NUMEROUS
SHOWERS DEVELOP LATER TODAY. WITH THE NEXT WEATHER SYSTEM IN THE
SERIES. PRECIPITATION CHANCES CONTINUE THROUGH FRIDAY. BELOW NORMAL
HIGH TEMPERATURES WILL CONTINUE AS WELL. CONDITIONS WILL START TO
DRY OUT FOR THE COMING WEEKEND...BUT TEMPERATURES WILL REMAIN BELOW
SEASONAL NORMALS.
&&
.DISCUSSION...
TODAY THROUGH FRIDAY...
BAND OF PRECIP THAT BROUGHT MUCH OF YESTERDAYS RAINFALL TO SOUTH-
CENTRAL ARIZONA HAS BEEN SLOWLY DISSIPATING. HOWEVER...A TRAILING
IMPULSE IS KEEPING SOME ISOLATED VERY LIGHT SHOWERS GOING. HRRR KEEPS
THESE GOING AND EXPANDS THE AREA TO THE LOWER COLORADO RIVER VALLEY
BEFORE SUNRISE. THE NEXT SYSTEM IS ALREADY MOVING INTO CALIFORNIA.
LIFTING MECHANISMS WITH THIS SYSTEM LOOK TO BE SIMILAR TO MONDAYS
WITH SOME LOWER LEVEL CONVERGENCE...UPPER LEVEL DIVERGENCE...AND A
DIV Q BULLSEYE. NAM NOT AS ROBUST AS THE GFS IS IN THOSE FIELDS.
LATEST MODELS INDICATE ITS ARRIVAL AND DEPARTURE WILL BE A BIT FASTER
THAN WAS DEPICTED IN PREVIOUS FORECAST PACKAGE. MADE ADJUSTMENTS TO
THE POPS ACCORDINGLY. SREF INDICATES SOME VERY MODEST CAPE FOR TODAY
AND TONIGHT. SPC HAS GENERAL THUNDER IN THE DAY 1 OUTLOOK FOR OUR
WESTERN AREAS...THOUGH SREF CAPE IS A BIT EAST OF THERE. TAKING THESE
FACTORS INTO ACCOUNT ALONG WITH MODEL LIFTED INDICES...ADDED SLIGHT
CHANCE OF THUNDERSTORMS FOR THIS AFTERNOON AND EVENING. OVERALL...QPF
IS LOOKING HIGHER WITH THIS SYSTEM THAN WHAT WE HAD WITH MONDAYS.
ADVISORY TYPE IMPACTS ARE QUITE POSSIBLE. SNOW LEVELS GENERALLY
REMAIN NEAR OR ABOVE 6000 FEET.
NEXT SYSTEM HAS TWO MAIN WAVES WITH IT. THE FIRST ONE MOVES IN WEDNESDAY
NIGHT AND EXITS OUR EASTERN AREAS THURSDAY EVENING. THE SECOND ONE IS
RIGHT ON ITS HEELS FOR FRIDAY. THE SECOND ONE HAS LESS LIFT GOING FOR
IT. SNOW LEVELS DROP THURSDAY AND FRIDAY...DOWN TO ABOUT 4000-4500 FEET
FRIDAY MORNING AND NOT CHANGING MUCH DURING THE DAY FRIDAY.
ADDITIONAL PRECIP FOR REST OF THIS WEEK...IS 1.5-2.5 INCHES OVER THE
FOOTHILLS AND HIGHER TERRAIN...1.0-1.5 INCHES OVER THE PHOENIX
AREA...AND 0.25-0.75 OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.
SATURDAY THROUGH MONDAY...
NORTHWEST FLOW AND WEAK DRY ADVECTION ACROSS THE AREA LOOKS LIKELY
THROUGH THE WEEKEND INTO NEXT WEEK...ALTHOUGH THERE`S SOME HINT AT A
DRY TROUGH MOVING THROUGH THE AREA ON SUNDAY /SOME INCREASED CLOUD
COVER AND THAT`S ABOUT IT/. SHOULD THIS TROUGH NOT DEVELOP...WE`LL NEED
TO KEEP AN EYE ON FOG POTENTIAL THIS WEEKEND /SATURDAY OR SUNDAY/ IF
THE BL DOESN`T SUFFICIENTLY DRY OUT. THE PATTERN IS CERTAINLY
CONDUCIVE FOR WIDESPREAD FOG DEVELOPMENT ACROSS THE AREA AND IT
WARRANTS MENTIONING. FAIRLY GOOD AGREEMENT OF STRONG UPPER RIDGING
ACROSS THE AREA BY MONDAY OF NEXT WEEK WITH TEMPERATURES RETURNING TO
EARLY JANUARY NORMALS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWERS WILL CONTINUE TO DISSIPATE IN INTENSITY AND COVERAGE ACROSS
THE PHOENIX METRO AREA THROUGH 06Z-08Z. THEREAFTER...THE BEST CHANCE
FOR PRECIPITATION WILL SHIFT INTO THE HIGHER TERRAIN NORTH AND EAST
OF THE VALLEY. CIGS WILL BE THE MAIN AVIATION WEATHER CONCERN OVER
THE NEXT 24 HOURS. PREPONDERANCE OF MODEL GUIDANCE CONTINUES TO
SUGGEST THAT CIGS WILL LOWER TO 4K FT LATER THIS MORNING AND PERSIST
THROUGH MUCH OF THE DAY TUESDAY. THERE IS ALSO A CHANCE THEY COULD
OCCASIONALLY LOWER TO AROUND 2500 FT AS SATURATION INCREASES BETWEEN
10Z AND 14Z.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NOT MUCH OF A THREAT FOR SHOWER ACTIVITY THROUGH 18Z WED...THOUGH THE
CHANCE FOR PRECIP WILL INCREASE TUESDAY AFTERNOON AND
EVENING...PARTICULARLY AT KIPL. UNTIL THEN...LOWER CIGS BETWEEN 2K
AFN 4K FT WILL PERSIST AT KBLH. SOMEWHAT BETTER CONDITIONS AT KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
SEVERAL WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICTS IN CLOSE
SUCCESSION THIS WEEK WITH HIGHLY VARIABLE RAINFALL OCCURRING EACH
DAY THROUGH FRIDAY...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY.
RAIN CHANCES TAPER OFF FOR THE WEEKEND. HUMIDITY WILL BE MUCH ABOVE
AVERAGE WITH MINIMUM VALUES NEAR AND ABOVE 45 PERCENT MOST DAYS ON
THE LOWER DESERTS AND MAX VALUES NEAR AND ABOVE 80 PERCENT MUCH OF
THE TIME. VALUES TREND DOWN FROM WEST TO EAST SATURDAY INTO SUNDAY
BUT GENERALLY REMAIN ABOVE 30 PERCENT MOST PLACES. EXPECT WELL BELOW
NORMAL HIGH TEMPERATURES THROUGH FRIDAY WITH DESERT HIGHS IN THE
50S...AND SLIGHT WARMING OVER THE WEEKEND AS HUMIDITIES START TO
FALL OFF. DESPITE THE ACTIVE WEATHER PATTERN NO STRONG WIND EVENTS
ARE EXPECTED BUT JUST BREEZY AT TIMES...MAINLY WEDNESDAY AND
THURSDAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ/LEINS
AVIATION...HIRSCH
FIRE WEATHER...AJ/CB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
920 PM MST MON JAN 4 2016
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
SEVERAL STORM SYSTEMS WILL MOVE THROUGH THE AREA THIS WEEK...BRINGING
COOLER AFTERNOON HIGHS...MILD NIGHTS...CLOUDY SKIES...AND AN ELEVATED
CHANCE OF RAINFALL THROUGH THE END OF THE WEEK. CONDITIONS WILL
START TO DRY OUT FOR THE COMING WEEKEND...BUT TEMPERATURES WILL
REMAIN BELOW SEASONAL NORMALS.
&&
.DISCUSSION...
MAIN MID-TROPOSPHERIC TROUGH AXIS CONTINUES TO PIVOT CYCLONICALLY
INTO NORTHERN AND EASTERN AZ. FROM A QUASI-GEOSTROPHIC
PERSPECTIVE...FORCING FOR ASCENT HAS BEEN WANING. HOWEVER...WEAK
ISENTROPIC MOISTURE TRANSPORT HAS BEEN SUFFICIENT TO SUPPORT A SOLID
LINE OF LIGHT TO MODERATE RAIN ACROSS SOUTH-CENTRAL AZ. LATEST RUNS
OF THE HRRR INDICATE THE LINE WILL CONTINUE TO DISSIPATE AS IT SLIDES
EASTWARD THIS EVENING. SOME LOCATIONS HAVE PICKED UP AS MUCH AS A
HALF OF AN INCH OF RAIN IN THIS LINE AND ANOTHER TENTH OF AN INCH IS
POSSIBLE...MAINLY ACROSS PORTIONS OF THE EAST VALLEY. GENERAL
CONSENSUS AMONGST THE HI-RES GUIDANCE IS THAT THE ACTIVITY WILL THEN
BECOME MORE ISOLATED THROUGH MIDNIGHT...BEFORE SHIFTING INTO THE
FAVORED AREAS OF THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX. MINOR
ADJUSTMENTS WERE MADE TO THE SHORT-TERM TEMPERATURES...DEWPOINTS AND
WINDS. OTHERWISE...THE FORECAST REMAINS ON TRACK.
&&
.PREVIOUS DISCUSSION...
LOOKING AT A MIXED CONFIDENCE FORECAST OVER THE NEXT FEW DAYS AS A
SERIES OF TROUGHS WILL MOVE THROUGH AND IMPACT THE AREA. THERE IS
VERY HIGH CONFIDENCE THAT ALL LOCATIONS WILL SEE MEASURABLE
PRECIPITATION AT SOME POINT /IF NOT SEVERAL TIMES OVER/ BY THE END OF
THE WEEK. THE UNCERTAINTY RESIDES IN EXACTLY WHEN THE RAIN WILL
OCCUR. RAINFALL LOOKS TO TAPER OFF THIS EVENING AND OVERNIGHT AS THE
INITIAL TROUGH AND RESULTING SUBSIDENCE BEGINS TO DOMINATE OVER THE
REGION. BY SOME INDICATIONS...TUESDAY MORNING SHOULD START OFF
RELATIVELY DRY. HOWEVER...MOIST ADVECTION /MODEST IVT SIGNAL FROM GFS
AND GEFS/ AND WEAK ISENTROPIC FORCING WILL BEGIN DURING THE DAY IN
ADVANCE OF A SECOND TROUGH...WITH RAINFALL POSSIBLE AGAIN TUESDAY
AFTERNOON AND EVENING. SREF PRECIP PLUMES ARE ADMITTEDLY ALL OVER THE
MAP UNTIL 06Z WEDNESDAY...AT WHICH POINT NEARLY ALL 26 MEMBERS
SUGGEST MEASURABLE PRECIP ACROSS THE DESERTS. DECIDING EXACTLY WHEN
THE RAIN WILL START IS A CHALLENGE...BUT POPS HAVE BEEN ADJUSTED TO
HIGHLIGHT THE LATE TUESDAY/EARLY WEDNESDAY TIME PERIOD AS ANOTHER
OPPORTUNITY FOR RAINFALL. THIS SECONDARY TROUGH SHOULD RAPIDLY MOVE
THROUGH THE AREA WEDNESDAY MORNING AND THE OPERATIONAL RUNS OF THE
ECMWF...NAM...AND GFS ARE EVEN TRYING TO SUGGEST SOME BREAKS IN THE
CLOUDS WEDNESDAY AFTERNOON.
TROUGH NUMBER 3 APPEARS POISED TO ARRIVE LATE WEDNESDAY NIGHT/EARLY
THURSDAY MORNING WITH ANOTHER NARROW BAND OF ENHANCED IVT AND
ISENTROPIC FORCING. ONCE AGAIN IT APPEARS THAT ELEVATED POPS ARE
WARRANTED AT THIS POINT AND THEY WERE NUDGED TOWARD THE LATEST RUN OF
THE NAEFS. FOLLOWING A BRIEF BREAK...THE FOURTH AND POSSIBLY FINAL
TROUGH LOOKS TO BE QUEUED UP FRIDAY MORNING WITH DRYING AND WEAK
UPPER RIDGING BEGINNING TO TAKE HOLD EARLY SATURDAY MORNING. QUITE A
BUSY WEEK TO SAY THE LEAST.
IN TERMS OF PRECIP AMOUNTS FOR THE WEEK AS A WHOLE...A HEALTHY BLEND
OF 50TH PERCENTILE QPF FROM ALL AVAILABLE GUIDANCE WEIGHTED TOWARD
WPC VALUES YIELDS ABOUT 1.5 TO 1.75 INCHES OVER THE DESERTS...WITH
SOME TOTALS PUSHING 3 INCHES NORTH/EAST OF PHOENIX. IT WOULD APPEAR
AT NO TIME SHOULD WE BE LOOKING AT MORE THAN A QUARTER TO A HALF INCH
OVER A 6 HR PERIOD. WASHES WILL LIKELY BEGIN RUNNING IN SOME AREAS
THIS WEEK AND SOME LOW-LYING AREAS COULD SEE MINOR HYDRO ISSUES...BUT
WIDESPREAD FLOODING DOESN`T APPEAR LIKELY AT THIS POINT. SHOULD THE
FORECAST VERIFY AS ADVERTISED...THIS SHOULD BE A STRATIFORM/BENEFICIAL
RAIN FOR THE AREA VS. A MAJOR HYDRO OR FLOODING EVENT. COLDER AIR
WILL EVENTUALLY WORK ITS WAY INTO THE AREA LATE IN THE WEEK RESULTING
IN SOME MIXED PRECIPITATION ACROSS THE HIGHEST MOUNTAIN PEAKS
NORTH/EAST OF PHOENIX. AT THIS POINT IT APPEARS ANY NOTEWORTHY
ACCUMULATIONS WILL BE CONFINED TO THE VERY HIGHEST PEAKS AND LOWEST
IMPACT AREAS ABOVE 6000 FT.
NORTHWEST FLOW AND WEAK DRY ADVECTION ACROSS THE AREA LOOKS LIKELY
THROUGH THE WEEKEND INTO NEXT WEEK...ALTHOUGH THERE`S SOME HINT AT A
DRY TROUGH MOVING THROUGH THE AREA ON SUNDAY /SOME INCREASED CLOUD
COVER AND THAT`S ABOUT IT/. SHOULD THIS TROUGH NOT DEVELOP...WE`LL NEED
TO KEEP AN EYE ON FOG POTENTIAL THIS WEEKEND /SATURDAY OR SUNDAY/ IF
THE BL DOESN`T SUFFICIENTLY DRY OUT. THE PATTERN IS CERTAINLY
CONDUCIVE FOR WIDESPREAD FOG DEVELOPMENT ACROSS THE AREA AND IT
WARRANTS MENTIONING. FAIRLY GOOD AGREEMENT OF STRONG UPPER RIDGING
ACROSS THE AREA BY MONDAY OF NEXT WEEK WITH TEMPERATURES RETURNING TO
EARLY JANUARY NORMALS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWERS WILL CONTINUE TO DISSIPATE IN INTENSITY AND COVERAGE ACROSS
THE PHOENIX METRO AREA THROUGH 06Z-08Z. THEREAFTER...THE BEST CHANCE
FOR PRECIPITATION WILL SHIFT INTO THE HIGHER TERRAIN NORTH AND EAST
OF THE VALLEY. CIGS WILL BE THE MAIN AVIATION WEATHER CONCERN OVER
THE NEXT 24 HOURS. PREPONDERANCE OF MODEL GUIDANCE CONTINUES TO
SUGGEST THAT CIGS WILL LOWER TO 4K FT LATER THIS MORNING AND PERSIST
THROUGH MUCH OF THE DAY TUESDAY. THERE IS ALSO A CHANCE THEY COULD
OCCASIONALLY LOWER TO AROUND 2500 FT AS SATURATION INCREASES BETWEEN
10Z AND 14Z.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NOT MUCH OF A THREAT FOR SHOWER ACTIVITY THROUGH 18Z WED...THOUGH THE
CHANCE FOR PRECIP WILL INCREASE TUESDAY AFTERNOON AND
EVENING...PARTICULARLY AT KIPL. UNTIL THEN...LOWER CIGS BETWEEN 2K
AFN 4K FT WILL PERSIST AT KBLH. SOMEWHAT BETTER CONDITIONS AT KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
SEVERAL WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICTS IN CLOSE
SUCCESSION THIS WEEK WITH HIGHLY VARIABLE RAINFALL OCCURRING EACH
DAY THROUGH FRIDAY...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY.
RAIN CHANCES TAPER OFF FOR THE WEEKEND. HUMIDITY WILL BE MUCH ABOVE
AVERAGE WITH MINIMUM VALUES NEAR AND ABOVE 45 PERCENT MOST DAYS ON
THE LOWER DESERTS AND MAX VALUES NEAR AND ABOVE 80 PERCENT MUCH OF
THE TIME. VALUES TREND DOWN FROM WEST TO EAST SATURDAY INTO SUNDAY
BUT GENERALLY REMAIN ABOVE 30 PERCENT MOST PLACES. EXPECT WELL BELOW
NORMAL HIGH TEMPERATURES THROUGH FRIDAY WITH DESERT HIGHS IN THE
50S...AND SLIGHT WARMING OVER THE WEEKEND AS HUMIDITIES START TO
FALL OFF. DESPITE THE ACTIVE WEATHER PATTERN NO STRONG WIND EVENTS
ARE EXPECTED BUT JUST BREEZY AT TIMES...MAINLY WEDNESDAY AND
THURSDAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...HIRSCH
FIRE WEATHER...AJ/CB
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
949 AM PST TUE JAN 5 2016
.SYNOPSIS...LINGERING SHOWERS WILL CONTINUE THROUGH THIS
AFTERNOON IN WAKE OF THIS MORNING`S FRONTAL PASSAGE. ANOTHER STORM
SYSTEM WILL IMPACT THE REGION LATE TONIGHT INTO WEDNESDAY MORNING
WITH LOCALLY HEAVY RAINFALL AND STRONGER WINDS. ADDITIONAL SHOWERS
WILL THEN BE POSSIBLE THROUGH THURSDAY.
&&
.DISCUSSION...AS OF 09:03 AM PST TUESDAY...THE FRONTAL BOUNDARY
THAT BROUGHT WIDESPREAD PRECIPITATION TO THE REGION THIS MORNING
CONTINUES TO PUSH INLAND. IN WAKE OF THE FRONTAL PASSAGE, LIGHT TO
OCCASIONALLY MODERATE RAINFALL CONTINUES WITH SOME ENHANCEMENT IN
RAINFALL RATES ALONG THE COAST OVER THE PAST HOUR. EXPECTING THESE
RAIN SHOWERS TO PERSIST INTO THE EARLY AFTERNOON WITH A BRIEF
BREAK IN PRECIPITATION EXPECTED LATE THIS EVENING ACROSS PORTIONS
OF THE REGION. ALSO, CANNOT RULE OUT AN ISOLATED THUNDERSTORM OR
TWO AS THE ATMOSPHERE BECOMES MORE UNSTABLE.
HAVE CANCELED THE FLASH FLOOD WATCH FOR SOUTHERN MONTEREY BAY
REGION AND THE SANTA LUCIA MOUNTAINS THAT WAS IN EFFECT THROUGH
THIS MORNING AS RAINFALL AMOUNTS WERE LESS THAN ORIGINALLY FORECAST
OVER THAT REGION. HOWEVER, WILL NEED TO EVALUATE THE POTENTIAL
FOR ADDITIONAL CONCERNS AS THE NEXT SYSTEM REMAINS ON TRACK TO
IMPACT THE REGION OVERNIGHT TONIGHT INTO WEDNESDAY MORNING. AT
THIS TIME, THIS NEXT SYSTEM APPEARS TO BRING SIMILAR RAINFALL
AMOUNTS TO THE REGION ON WEDNESDAY MORNING WITH LINGERING
PRECIPITATION INTO THURSDAY. PLEASE SEE THE PREVIOUS FORECAST
DISCUSSION BELOW FOR MORE DETAILS AND LOOK FOR OUR UPDATED
FORECAST LATER THIS AFTERNOON.
&&
.PREV DISCUSSION...AS OF 2:30 AM PST TUESDAY...AS FORECAST,
WIDESPREAD RAINFALL IS CURRENTLY MOVING INTO OUR CWA AT THIS HOUR.
THIS IS ASSOCIATED WITH A FRONT THAT IS ALSO ABOUT TO ENTER THE SF
BAY AREA. SO FAR RAIN RATES HAVE GENERALLY BEEN ON THE LIGHT SIDE
WITH THE BULK OF PRECIP OVER THE NORTH BAY. HOWEVER, OVER THE PAST
HOUR POCKETS OF MODERATE TO LOCALLY HEAVY RAINFALL HAVE MADE THEIR
WAY TO THE SAN MATEO AND SAN FRANCISCO COAST. HRRR SEEMS TO HAVE A
GOOD HANDLE ON THE GENERAL TIMING BUT HAS BEEN UNDERDOING AMOUNTS,
SO WILL BE USING THE DATA WITH SOME CAUTION. REGARDLESS, THE MAIN
BAND WILL PROGRESS THROUGH THE BAY AREA OVER THE NEXT COUPLE OF
HOURS WITH SANTA CLARA AND MONTEREY BAY REGION LOOKING AT MORE OF
A 3 TO 6 AM RANGE FOR THE BULK OF THEIR RAIN. AMOUNTS STILL
FORECAST TO BE GENERALLY 1/3" TO 2/3" FOR MOST URBAN SPOTS WITH
1-2" POSSIBLE FOR HIGHER ELEVATION LOCATIONS. WINDS HAVE ALSO BEEN
PICKING UP AS THE FRONT APPROACHES WITH A FAIR NUMBER OF SPOTS NOW
GUSTING TO OVER 25 MPH. SPEEDS WILL GENERALLY PEAK THIS MORNING
AND SHOULD MOSTLY STAY UNDER ADVISORY LEVELS.
FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE BIG SUR REGION
INCLUDING THE SANTA LUCIA MOUNTAINS. TIMING HAS BEEN SLIGHTLY
ADJUSTED TO NOW PUSH THE WATCH TO 10 AM WITH MODELS SUGGESTING THE
POTENTIAL FOR MODERATE TO HEAVY RAIN IN THAT REGION UNTIL LATE IN
THE MORNING. FOR THE REST OF OUR REGION, SO FAR ONLY TWO REPORTS
OF MINOR FLOODING OFF THE CHP PAGE, ALTHOUGH THAT NUMBER SHOULD
INCREASE THROUGH THE NEXT FEW HOURS.
RAIN WILL CHANGE OVER TO SHOWERS AND POSSIBLE THUNDERSTORMS DUE TO
A MORE UNSTABLE ATMOSPHERE WITH PRECIPITATION LIKELY FOR AT LEAST
A PORTION OF THE AFTERNOON AND EVENING HOURS ACROSS THE CWA. A
SECOND POTENT SYSTEM WILL MOVE BACK TO OUR AREA DIRECTLY FROM THE
WEST WITH THE BULK OF THE RAIN FORECAST TO BEGIN AROUND SUNRISE ON
WEDNESDAY. RAIN WILL LIKELY BE MODERATE TO HEAVY AT TIMES WITH THE
MORNING COMMUTE TOMORROW LOOKING VERY CHALLENGING. RAIN WILL
SWITCH TO SHOWERS AND POTENTIALLY THUNDERSTORMS LATER ON
WEDNESDAY. SOUTHERLY WINDS WILL BE GUSTY AND SHOULD BE STRONGER
THAN WITH THE SYSTEM GOING THROUGH TODAY. DAY CREW MAY NEED TO
HOIST A WIND ADVISORY PARTICULARLY ALONG THE COAST PLUS THE NORTH
AND EAST BAY HILLS. RAINFALL AMOUNTS FOR WEDNESDAY ARE FORECAST TO
BE SIMILAR TO AMOUNTS FOR TODAY. GENERALLY 1/2" TO 1" BY THE
EVENING FOR URBAN SPOTS WITH COASTAL RANGES LOOKING FOR 1.5" TO
3". DEPENDING ON HOW THE RAIN TOTALS END UP TODAY AND HOW THE
HIGHER RESOLUTION MODELS LOOK LATER TODAY, ANOTHER FLASH FLOOD
WATCH MAY NEED TO BE ISSUED.
A THIRD AND MUCH WEAKER SYSTEM WILL GO THROUGH ON THURSDAY. THIS
WILL GENERALLY DROP LESS THAN 1/4" IN MOST SPOTS WITH LOCALLY UP
TO 1/2" FOR HIGHER ELEVATION LOCATIONS. SHOWERS WILL GENERALLY
COME TO AN END BY EARLY FRIDAY. THAT BREAK WILL LIKELY BE SHORT AS
WELL AS ANOTHER SYSTEM RACES THROUGH LATE FRIDAY INTO SATURDAY. AT
THIS TIME, THAT SYSTEM DOES NOT LOOK VERY STRONG.
TWO OR THREE MORE SYSTEMS ARE FORECAST FOR NEXT WEEK.
&&
.AVIATION...AS OF 9:48 AM PST TUESDAY...DIFFICULT AND DYNAMIC
FORECAST AS ONE SYSTEM IS CURRENTLY SWEEPING THROUGH THE BAY AREA
THIS MORNING AND ANOTHER SYSTEM APPROACHES FROM THE WEST. IN THE
NEAR TERM...LIGHT TO MODERATE RAIN WILL CONTINUE THROUGH EARLY
THIS AFTERNOON (20ZISH) WITH SOME CIGS LIFTING THIS AFTERNOON. A
BRIEF BREAK IN THE ACTION THEN RAIN RETURNS LATE TONIGHT IMPACTING
THE AM RUSH AGAIN FOR WEDNESDAY. WINDS WILL DEFINITELY BE
PROBLEMATIC WITH NAILING DOWN DIRECTION AND SPEED AT TIMES.
HOWEVER...WINDS WILL LIKELY INCREASE TONIGHT AND REMAIN GUSTY
TOMORROW. OVERALL CONF IS LOW TO MODERATE.
LASTLY...MODELS AND CURRENT PUBLIC FORECAST HAS A POSSIBILITY OF TSTORMS
THIS AFTERNOON AND WEDNESDAY...BUT CONF IS NOT HIGH ENOUGH TO HAVE
TSRA IN ANY TAF LOCATION.
VICINITY OF KSFO...LIGHT TO MODERATE RAIN AND SE WINDS WILL
CONTINUE THROUGH 19 TO 20Z. LATEST GUIDANCE SUGGESTS A WIND SHIFT
AROUND 19 TO 20Z AND BUOYS OFF THE COAST HAVE ALREADY SHIFTED.
THEREFORE...SE TO SW AROUND 19Z WILL BE IN THE SFO TAF. SW TO W
WINDS THIS AFTERNOON WITH VCSH. RAIN RETURNS TONIGHT AFTER 06Z AND
MAY BE HEAVY TOMORROW AM AROUND 12Z.
SFO BRIDGE APPROACH...FOR THE MOST PART SIMILAR TO KSFO...BUT AT TIMES CONDITIONS
WILL LIKELY VARY IN SUCH A SMALL DISTANCE FROM THE BRIDGE TO THE
RUNWAY WITH CIGS AND WINDS.
MONTEREY BAY AREA TERMINALS...LIGHT TO MODERATE RAIN WITH MVFR
CONDITIONS THROUGH THIS AFTERNOON. VCSH THIS EVENING WITH RAIN
RETURNING LATE TONIGHT. GUSTY SE WINDS WILL BE POSSIBLE AT KSNS.
&&
.MARINE...AS OF 09:36 AM PST TUESDAY...ACTIVE WEATHER WILL
CONTINUE OVER THE COASTAL WATERS AS SEVERAL STORMS MOVE THROUGH
THE REGION. ONE STORM WILL EXIT THE REGION TODAY...BUT ANOTHER
STORM WILL APPROACH TONIGHT. THE APPROACHING STORM WILL BRING
ANOTHER ROUND OF MODERATE TO HEAVY RAIN AND GUSTY WINDS. SWELLS
WILL BUILD THROUGH THE PERIOD AS WELL.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ENTIRE COASTLINE
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: MM
MARINE: MM
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
920 AM PST TUE JAN 5 2016
.SYNOPSIS...LINGERING SHOWERS WILL CONTINUE THROUGH THIS
AFTERNOON IN WAKE OF THIS MORNING`S FRONTAL PASSAGE. ANOTHER STORM
SYSTEM WILL IMPACT THE REGION LATE TONIGHT INTO WEDNESDAY MORNING
WITH LOCALLY HEAVY RAINFALL AND STRONGER WINDS. ADDITIONAL SHOWERS
WILL THEN BE POSSIBLE THROUGH THURSDAY.
&&
.DISCUSSION...AS OF 09:03 AM PST TUESDAY...THE FRONTAL BOUNDARY
THAT BROUGHT WIDESPREAD PRECIPITATION TO THE REGION THIS MORNING
CONTINUES TO PUSH INLAND. IN WAKE OF THE FRONTAL PASSAGE, LIGHT TO
OCCASIONALLY MODERATE RAINFALL CONTINUES WITH SOME ENHANCEMENT IN
RAINFALL RATES ALONG THE COAST OVER THE PAST HOUR. EXPECTING THESE
RAIN SHOWERS TO PERSIST INTO THE EARLY AFTERNOON WITH A BRIEF
BREAK IN PRECIPITATION EXPECTED LATE THIS EVENING ACROSS PORTIONS
OF THE REGION. ALSO, CANNOT RULE OUT AN ISOLATED THUNDERSTORM OR
TWO AS THE ATMOSPHERE BECOMES MORE UNSTABLE.
HAVE CANCELED THE FLASH FLOOD WATCH FOR SOUTHERN MONTEREY BAY
REGION AND THE SANTA LUCIA MOUNTAINS THAT WAS IN EFFECT THROUGH
THIS MORNING AS RAINFALL AMOUNTS WERE LESS THAN ORIGINALLY FORECAST
OVER THAT REGION. HOWEVER, WILL NEED TO EVALUATE THE POTENTIAL
FOR ADDITIONAL CONCERNS AS THE NEXT SYSTEM REMAINS ON TRACK TO
IMPACT THE REGION OVERNIGHT TONIGHT INTO WEDNESDAY MORNING. AT
THIS TIME, THIS NEXT SYSTEM APPEARS TO BRING SIMILAR RAINFALL
AMOUNTS TO THE REGION ON WEDNESDAY MORNING WITH LINGERING
PRECIPITATION INTO THURSDAY. PLEASE SEE THE PREVIOUS FORECAST
DISCUSSION BELOW FOR MORE DETAILS AND LOOK FOR OUR UPDATED
FORECAST LATER THIS AFTERNOON.
&&
.PREV DISCUSSION...AS OF 2:30 AM PST TUESDAY...AS FORECAST,
WIDESPREAD RAINFALL IS CURRENTLY MOVING INTO OUR CWA AT THIS HOUR.
THIS IS ASSOCIATED WITH A FRONT THAT IS ALSO ABOUT TO ENTER THE SF
BAY AREA. SO FAR RAIN RATES HAVE GENERALLY BEEN ON THE LIGHT SIDE
WITH THE BULK OF PRECIP OVER THE NORTH BAY. HOWEVER, OVER THE PAST
HOUR POCKETS OF MODERATE TO LOCALLY HEAVY RAINFALL HAVE MADE THEIR
WAY TO THE SAN MATEO AND SAN FRANCISCO COAST. HRRR SEEMS TO HAVE A
GOOD HANDLE ON THE GENERAL TIMING BUT HAS BEEN UNDERDOING AMOUNTS,
SO WILL BE USING THE DATA WITH SOME CAUTION. REGARDLESS, THE MAIN
BAND WILL PROGRESS THROUGH THE BAY AREA OVER THE NEXT COUPLE OF
HOURS WITH SANTA CLARA AND MONTEREY BAY REGION LOOKING AT MORE OF
A 3 TO 6 AM RANGE FOR THE BULK OF THEIR RAIN. AMOUNTS STILL
FORECAST TO BE GENERALLY 1/3" TO 2/3" FOR MOST URBAN SPOTS WITH
1-2" POSSIBLE FOR HIGHER ELEVATION LOCATIONS. WINDS HAVE ALSO BEEN
PICKING UP AS THE FRONT APPROACHES WITH A FAIR NUMBER OF SPOTS NOW
GUSTING TO OVER 25 MPH. SPEEDS WILL GENERALLY PEAK THIS MORNING
AND SHOULD MOSTLY STAY UNDER ADVISORY LEVELS.
FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE BIG SUR REGION
INCLUDING THE SANTA LUCIA MOUNTAINS. TIMING HAS BEEN SLIGHTLY
ADJUSTED TO NOW PUSH THE WATCH TO 10 AM WITH MODELS SUGGESTING THE
POTENTIAL FOR MODERATE TO HEAVY RAIN IN THAT REGION UNTIL LATE IN
THE MORNING. FOR THE REST OF OUR REGION, SO FAR ONLY TWO REPORTS
OF MINOR FLOODING OFF THE CHP PAGE, ALTHOUGH THAT NUMBER SHOULD
INCREASE THROUGH THE NEXT FEW HOURS.
RAIN WILL CHANGE OVER TO SHOWERS AND POSSIBLE THUNDERSTORMS DUE TO
A MORE UNSTABLE ATMOSPHERE WITH PRECIPITATION LIKELY FOR AT LEAST
A PORTION OF THE AFTERNOON AND EVENING HOURS ACROSS THE CWA. A
SECOND POTENT SYSTEM WILL MOVE BACK TO OUR AREA DIRECTLY FROM THE
WEST WITH THE BULK OF THE RAIN FORECAST TO BEGIN AROUND SUNRISE ON
WEDNESDAY. RAIN WILL LIKELY BE MODERATE TO HEAVY AT TIMES WITH THE
MORNING COMMUTE TOMORROW LOOKING VERY CHALLENGING. RAIN WILL
SWITCH TO SHOWERS AND POTENTIALLY THUNDERSTORMS LATER ON
WEDNESDAY. SOUTHERLY WINDS WILL BE GUSTY AND SHOULD BE STRONGER
THAN WITH THE SYSTEM GOING THROUGH TODAY. DAY CREW MAY NEED TO
HOIST A WIND ADVISORY PARTICULARLY ALONG THE COAST PLUS THE NORTH
AND EAST BAY HILLS. RAINFALL AMOUNTS FOR WEDNESDAY ARE FORECAST TO
BE SIMILAR TO AMOUNTS FOR TODAY. GENERALLY 1/2" TO 1" BY THE
EVENING FOR URBAN SPOTS WITH COASTAL RANGES LOOKING FOR 1.5" TO
3". DEPENDING ON HOW THE RAIN TOTALS END UP TODAY AND HOW THE
HIGHER RESOLUTION MODELS LOOK LATER TODAY, ANOTHER FLASH FLOOD
WATCH MAY NEED TO BE ISSUED.
A THIRD AND MUCH WEAKER SYSTEM WILL GO THROUGH ON THURSDAY. THIS
WILL GENERALLY DROP LESS THAN 1/4" IN MOST SPOTS WITH LOCALLY UP
TO 1/2" FOR HIGHER ELEVATION LOCATIONS. SHOWERS WILL GENERALLY
COME TO AN END BY EARLY FRIDAY. THAT BREAK WILL LIKELY BE SHORT AS
WELL AS ANOTHER SYSTEM RACES THROUGH LATE FRIDAY INTO SATURDAY. AT
THIS TIME, THAT SYSTEM DOES NOT LOOK VERY STRONG.
TWO OR THREE MORE SYSTEMS ARE FORECAST FOR NEXT WEEK.
&&
.AVIATION...AS OF 3:59 AM PST TUESDAY...A PAIR OF STORM SYSTEMS
WILL PASS THROUGH THE REGION THROUGH THE 30 HOUR TAF PERIOD. THE
FIRST FRONTAL SYSTEM IS PASSING THROUGH THE REGION NOW... WITH
LIGHT TO MODERATE RAIN AND VFR TO MVFR CIGS REPORTED WITH THE
FROPA. SOUTHERLY WINDS WILL VEER TOWARDS THE WEST INTO AFTERNOON
IN THE POST FRONTAL ENVIRONMENT. CIGS WILL LIFT BRIEFLY INTO THE
AFTERNOON AND EARLY EVENING AHEAD OF THE NEXT FRONTAL SYSTEM THAT
IS EXPECTED TO PASS THROUGH THE REGION BEGINNING AROUND 10-12Z
WED. WINDS WILL BACK TO THE SOUTH-SOUTHEAST AHEAD OF THE NEXT
FRONTAL PASSAGE AND BECOME GUSTY... WITH SOME LOCATIONS SEEING
GUSTS INTO THE 30-40MPH RANGE EARLY WEDNESDAY MORNING.
PREDOMINATELY MVFR TO VFR CIGS EXPECTED WITH SECOND FRONTAL
SYSTEM.
VICINITY OF KSFO...BORDERLINE MVFR CIGS WITH CIGS EXPECTED TO
REMAIN ABOVE CRITICAL 1600FT LEVEL. MODERATE TO HEAVY RAIN THROUGH
THE PREDAWN HOURS... THEN RAIN WILL GRADUALLY TAPER OFF INTO THE
EARLY AFTERNOON. BRIEF IMPROVEMENT IN CONDITIONS FROM 02-06Z
WED... THEN DETERIORATING CIGS AND INCREASING SOUTHEAST WINDS WITH
NEXT FRONTAL PASSAGE AFTER 08Z WED. SOUTHEAST GUSTS UP TO OR
EXCEEDING 40MPH POSSIBLE BY 12Z WED.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...PREDOMINATELY VFR WITH OCCASIONAL
MVFR CIGS ACCOMPANYING FROPA. LIGHT TO MODERATE RAIN NOW THROUGH
00Z WED. THEN IMPROVING CIGS FROM 01Z-09Z WED. DETERIORATING CIGS
AND INCREASING SOUTHEAST WINDS AFTER 10Z WED IN ANTICIPATION OF
SECOND FROPA.
&&
.MARINE...AS OF 09:03 AM PST TUESDAY...ACTIVE WEATHER WILL
CONTINUE OVER THE COASTAL WATERS AS SEVERAL STORMS MOVE THROUGH
THE REGION. ONE STORM WILL EXIT THE REGION TODAY...BUT ANOTHER
STORM WILL APPROACH TONIGHT. THE APPROACHING STORM WILL BRING
ANOTHER ROUND OF MODERATE TO HEAVY RAIN AND GUSTY WINDS. SWELLS
WILL BUILD THROUGH THE PERIOD AS WELL.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ALL COASTAL ZONES
SCA...ROUGH BAR ADVISORY FOR SF BAR
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: DRP
MARINE: MM
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
404 AM PST TUE JAN 5 2016
...MODERATE TO HEAVY RAIN AND GUSTY WINDS THIS MORNING...
...ANOTHER POTENT STORM FORECAST FOR WEDNESDAY...
.SYNOPSIS...A COLD FRONT INTO THE MORNING WILL PRODUCE HEAVY RAIN
AND LOCALLY STRONG WINDS. ANOTHER STRONG STORM WITH HEAVY RAIN AND
EVEN STRONGER WINDS IS EXPECTED ON WEDNESDAY. MORE SHOWERS WILL
FOLLOW ON THURSDAY.
&&
.DISCUSSION...AS OF 2:30 AM PST TUESDAY...AS FORECAST, WIDESPREAD
RAINFALL IS CURRENTLY MOVING INTO OUR CWA AT THIS HOUR. THIS IS
ASSOCIATED WITH A FRONT THAT IS ALSO ABOUT TO ENTER THE SF
BAY AREA. SO FAR RAIN RATES HAVE GENERALLY BEEN ON THE LIGHT SIDE
WITH THE BULK OF PRECIP OVER THE NORTH BAY. HOWEVER, OVER THE PAST
HOUR POCKETS OF MODERATE TO LOCALLY HEAVY RAINFALL HAVE MADE THEIR
WAY TO THE SAN MATEO AND SAN FRANCISCO COAST. HRRR SEEMS TO HAVE A
GOOD HANDLE ON THE GENERAL TIMING BUT HAS BEEN UNDERDOING AMOUNTS,
SO WILL BE USING THE DATA WITH SOME CAUTION. REGARDLESS, THE MAIN
BAND WILL PROGRESS THROUGH THE BAY AREA OVER THE NEXT COUPLE OF
HOURS WITH SANTA CLARA AND MONTEREY BAY REGION LOOKING AT MORE OF
A 3 TO 6 AM RANGE FOR THE BULK OF THEIR RAIN. AMOUNTS STILL
FORECAST TO BE GENERALLY 1/3" TO 2/3" FOR MOST URBAN SPOTS WITH
1-2" POSSIBLE FOR HIGHER ELEVATION LOCATIONS. WINDS HAVE ALSO BEEN
PICKING UP AS THE FRONT APPROACHES WITH A FAIR NUMBER OF SPOTS NOW
GUSTING TO OVER 25 MPH. SPEEDS WILL GENERALLY PEAK THIS MORNING
AND SHOULD MOSTLY STAY UNDER ADVISORY LEVELS.
FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE BIG SUR REGION
INCLUDING THE SANTA LUCIA MOUNTAINS. TIMING HAS BEEN SLIGHTLY
ADJUSTED TO NOW PUSH THE WATCH TO 10 AM WITH MODELS SUGGESTING THE
POTENTIAL FOR MODERATE TO HEAVY RAIN IN THAT REGION UNTIL LATE IN
THE MORNING. FOR THE REST OF OUR REGION, SO FAR ONLY TWO REPORTS
OF MINOR FLOODING OFF THE CHP PAGE, ALTHOUGH THAT NUMBER SHOULD
INCREASE THROUGH THE NEXT FEW HOURS.
RAIN WILL CHANGE OVER TO SHOWERS AND POSSIBLE THUNDERSTORMS DUE TO
A MORE UNSTABLE ATMOSPHERE WITH PRECIPITATION LIKELY FOR AT LEAST
A PORTION OF THE AFTERNOON AND EVENING HOURS ACROSS THE CWA. A
SECOND POTENT SYSTEM WILL MOVE BACK TO OUR AREA DIRECTLY FROM THE
WEST WITH THE BULK OF THE RAIN FORECAST TO BEGIN AROUND SUNRISE ON
WEDNESDAY. RAIN WILL LIKELY BE MODERATE TO HEAVY AT TIMES WITH THE
MORNING COMMUTE TOMORROW LOOKING VERY CHALLENGING. RAIN WILL
SWITCH TO SHOWERS AND POTENTIALLY THUNDERSTORMS LATER ON
WEDNESDAY. SOUTHERLY WINDS WILL BE GUSTY AND SHOULD BE STRONGER
THAN WITH THE SYSTEM GOING THROUGH TODAY. DAY CREW MAY NEED TO
HOIST A WIND ADVISORY PARTICULARLY ALONG THE COAST PLUS THE NORTH
AND EAST BAY HILLS. RAINFALL AMOUNTS FOR WEDNESDAY ARE FORECAST TO
BE SIMILAR TO AMOUNTS FOR TODAY. GENERALLY 1/2" TO 1" BY THE
EVENING FOR URBAN SPOTS WITH COASTAL RANGES LOOKING FOR 1.5" TO
3". DEPENDING ON HOW THE RAIN TOTALS END UP TODAY AND HOW THE
HIGHER RESOLUTION MODELS LOOK LATER TODAY, ANOTHER FLASH FLOOD
WATCH MAY NEED TO BE ISSUED.
A THIRD AND MUCH WEAKER SYSTEM WILL GO THROUGH ON THURSDAY. THIS
WILL GENERALLY DROP LESS THAN 1/4" IN MOST SPOTS WITH LOCALLY UP
TO 1/2" FOR HIGHER ELEVATION LOCATIONS. SHOWERS WILL GENERALLY
COME TO AN END BY EARLY FRIDAY. THAT BREAK WILL LIKELY BE SHORT AS
WELL AS ANOTHER SYSTEM RACES THROUGH LATE FRIDAY INTO SATURDAY. AT
THIS TIME, THAT SYSTEM DOES NOT LOOK VERY STRONG.
TWO OR THREE MORE SYSTEMS ARE FORECAST FOR NEXT WEEK.
&&
.AVIATION...AS OF 3:59 AM PST TUESDAY...A PAIR OF STORM SYSTEMS
WILL PASS THROUGH THE REGION THROUGH THE 30 HOUR TAF PERIOD. THE
FIRST FRONTAL SYSTEM IS PASSING THROUGH THE REGION NOW... WITH
LIGHT TO MODERATE RAIN AND VFR TO MVFR CIGS REPORTED WITH THE
FROPA. SOUTHERLY WINDS WILL VEER TOWARDS THE WEST INTO AFTERNOON
IN THE POST FRONTAL ENVIRONMENT. CIGS WILL LIFT BRIEFLY INTO THE
AFTERNOON AND EARLY EVENING AHEAD OF THE NEXT FRONTAL SYSTEM THAT
IS EXPECTED TO PASS THROUGH THE REGION BEGINNING AROUND 10-12Z
WED. WINDS WILL BACK TO THE SOUTH-SOUTHEAST AHEAD OF THE NEXT
FRONTAL PASSAGE AND BECOME GUSTY... WITH SOME LOCATIONS SEEING
GUSTS INTO THE 30-40MPH RANGE EARLY WEDNESDAY MORNING.
PREDOMINATELY MVFR TO VFR CIGS EXPECTED WITH SECOND FRONTAL
SYSTEM.
VICINITY OF KSFO...BORDERLINE MVFR CIGS WITH CIGS EXPECTED TO
REMAIN ABOVE CRITICAL 1600FT LEVEL. MODERATE TO HEAVY RAIN THROUGH
THE PREDAWN HOURS... THEN RAIN WILL GRADUALLY TAPER OFF INTO THE
EARLY AFTERNOON. BRIEF IMPROVEMENT IN CONDITIONS FROM 02-06Z
WED... THEN DETERIORATING CIGS AND INCREASING SOUTHEAST WINDS WITH
NEXT FRONTAL PASSAGE AFTER 08Z WED. SOUTHEAST GUSTS UP TO OR
EXCEEDING 40MPH POSSIBLE BY 12Z WED.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...PREDOMINATELY VFR WITH OCCASIONAL
MVFR CIGS ACCOMPANYING FROPA. LIGHT TO MODERATE RAIN NOW THROUGH
00Z WED. THEN IMPROVING CIGS FROM 01Z-09Z WED. DETERIORATING CIGS
AND INCREASING SOUTHEAST WINDS AFTER 10Z WED IN ANTICIPATION OF
SECOND FROPA.
&&
.MARINE...AS OF 03:53 AM PST TUESDAY...A SERIES OF STORMS WILL
MOVE THROUGH THE COASTAL WATERS THIS WEEK LEADING TO BUILDING WEST
SWELLS TODAY THROUGH THURSDAY. EXPECT PERIODS OF MODERATE TO HEAVY
RAIN AND OCCASIONALLY GUSTY WINDS WITH EACH FRONTAL PASSAGE. THE
CURRENT FRONTAL PASSAGE IS PUSHING ONSHORE THIS MORNING. THE NEXT
FRONTAL PASSAGE WILL COME LATE TONIGHT. WINDS AND WAVES TAPER OFF
LATE IN THE WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ALL COASTAL ZONES
FLASH FLOOD WATCH...BIG SUR COAST AND SANTA LUCIA MTNS.
SCA...SF BAY UNTIL 9 AM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 9 AM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 9 AM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 9 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 9 AM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 9 AM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 9 AM
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
&&
$$
PUBLIC FORECAST: RWW/BELL
AVIATION: DRP
MARINE: DRP
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
234 AM PST TUE JAN 5 2016
...MODERATE TO HEAVY RAIN AND GUSTY WINDS THIS MORNING...
...ANOTHER POTENT STORM FORECAST FOR WEDNESDAY...
.SYNOPSIS...A COLD FRONT INTO THE MORNING WILL PRODUCE HEAVY RAIN
AND LOCALLY STRONG WINDS. ANOTHER STRONG STORM WITH HEAVY RAIN AND
EVEN STRONGER WINDS IS EXPECTED ON WEDNESDAY. MORE SHOWERS WILL
FOLLOW ON THURSDAY.
&&
.DISCUSSION...AS OF 2:30 AM PST TUESDAY...AS FORECAST, WIDESPREAD
RAINFALL IS CURRENTLY MOVING INTO OUR CWA AT THIS HOUR. THIS IS
ASSOCIATED WITH A FRONT THAT IS ALSO ABOUT TO ENTER THE SF
BAY AREA. SO FAR RAIN RATES HAVE GENERALLY BEEN ON THE LIGHT SIDE
WITH THE BULK OF PRECIP OVER THE NORTH BAY. HOWEVER, OVER THE PAST
HOUR POCKETS OF MODERATE TO LOCALLY HEAVY RAINFALL HAVE MADE THEIR
WAY TO THE SAN MATEO AND SAN FRANCISCO COAST. HRRR SEEMS TO HAVE A
GOOD HANDLE ON THE GENERAL TIMING BUT HAS BEEN UNDERDOING AMOUNTS,
SO WILL BE USING THE DATA WITH SOME CAUTION. REGARDLESS, THE MAIN
BAND WILL PROGRESS THROUGH THE BAY AREA OVER THE NEXT COUPLE OF
HOURS WITH SANTA CLARA AND MONTEREY BAY REGION LOOKING AT MORE OF
A 3 TO 6 AM RANGE FOR THE BULK OF THEIR RAIN. AMOUNTS STILL
FORECAST TO BE GENERALLY 1/3" TO 2/3" FOR MOST URBAN SPOTS WITH
1-2" POSSIBLE FOR HIGHER ELEVATION LOCATIONS. WINDS HAVE ALSO BEEN
PICKING UP AS THE FRONT APPROACHES WITH A FAIR NUMBER OF SPOTS NOW
GUSTING TO OVER 25 MPH. SPEEDS WILL GENERALLY PEAK THIS MORNING
AND SHOULD MOSTLY STAY UNDER ADVISORY LEVELS.
FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE BIG SUR REGION
INCLUDING THE SANTA LUCIA MOUNTAINS. TIMING HAS BEEN SLIGHTLY
ADJUSTED TO NOW PUSH THE WATCH TO 10 AM WITH MODELS SUGGESTING THE
POTENTIAL FOR MODERATE TO HEAVY RAIN IN THAT REGION UNTIL LATE IN
THE MORNING. FOR THE REST OF OUR REGION, SO FAR ONLY TWO REPORTS
OF MINOR FLOODING OFF THE CHP PAGE, ALTHOUGH THAT NUMBER SHOULD
INCREASE THROUGH THE NEXT FEW HOURS.
RAIN WILL CHANGE OVER TO SHOWERS AND POSSIBLE THUNDERSTORMS DUE TO
A MORE UNSTABLE ATMOSPHERE WITH PRECIPITATION LIKELY FOR AT LEAST
A PORTION OF THE AFTERNOON AND EVENING HOURS ACROSS THE CWA. A
SECOND POTENT SYSTEM WILL MOVE BACK TO OUR AREA DIRECTLY FROM THE
WEST WITH THE BULK OF THE RAIN FORECAST TO BEGIN AROUND SUNRISE ON
WEDNESDAY. RAIN WILL LIKELY BE MODERATE TO HEAVY AT TIMES WITH THE
MORNING COMMUTE TOMORROW LOOKING VERY CHALLENGING. RAIN WILL
SWITCH TO SHOWERS AND POTENTIALLY THUNDERSTORMS LATER ON
WEDNESDAY. SOUTHERLY WINDS WILL BE GUSTY AND SHOULD BE STRONGER
THAN WITH THE SYSTEM GOING THROUGH TODAY. DAY CREW MAY NEED TO
HOIST A WIND ADVISORY PARTICULARLY ALONG THE COAST PLUS THE NORTH
AND EAST BAY HILLS. RAINFALL AMOUNTS FOR WEDNESDAY ARE FORECAST TO
BE SIMILAR TO AMOUNTS FOR TODAY. GENERALLY 1/2" TO 1" BY THE
EVENING FOR URBAN SPOTS WITH COASTAL RANGES LOOKING FOR 1.5" TO
3". DEPENDING ON HOW THE RAIN TOTALS END UP TODAY AND HOW THE
HIGHER RESOLUTION MODELS LOOK LATER TODAY, ANOTHER FLASH FLOOD
WATCH MAY NEED TO BE ISSUED.
A THIRD AND MUCH WEAKER SYSTEM WILL GO THROUGH ON THURSDAY. THIS
WILL GENERALLY DROP LESS THAN 1/4" IN MOST SPOTS WITH LOCALLY UP
TO 1/2" FOR HIGHER ELEVATION LOCATIONS. SHOWERS WILL GENERALLY
COME TO AN END BY EARLY FRIDAY. THAT BREAK WILL LIKELY BE SHORT AS
WELL AS ANOTHER SYSTEM RACES THROUGH LATE FRIDAY INTO SATURDAY. AT
THIS TIME, THAT SYSTEM DOES NOT LOOK VERY STRONG.
TWO OR THREE MORE SYSTEMS ARE FORECAST FOR NEXT WEEK.
&&
.AVIATION...AS OF 9:38 PM PST MONDAY...STEADY LIGHT TO LOCALLY
MODERATE RAIN WILL CONTINUE TO SPREAD OVER THE AREA THIS EVENING.
RAIN WILL BE MODERATE TO HEAVY AT TIMES LATE TONIGHT AND TUESDAY
MORNING PER STRENGTHENING WARM AIR ADVECTION THAT IS FOLLOWED BY
THE PASSAGE OF A COLD FRONT EARLY TUESDAY MORNING. SHOWERS LINGER
TUESDAY THEN MORE RAIN ARRIVES TUESDAY NIGHT INTO WEDNESDAY MORNING.
MVFR CIGS AND VSBYS EXCEPT VSBYS LOWERING TO IFR IN MODERATE TO
HEAVY RAIN.
VICINITY OF KSFO...MVFR CIGS. STEADIER RAIN OVERNIGHT WITH A PERIOD
OF GUSTY SE WINDS AND HEAVIER RAIN NEAR THE COLD FRONTAL PASSAGE
TUESDAY MORNING. SHOWERS TUESDAY THEN RAIN RETURNS LATER TUE NIGHT
INTO WEDNESDAY.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR/MVFR CIGS. INCREASING SE WINDS
THIS EVENING BECOMING SW TUESDAY MORNING. RAIN ARRIVING TONIGHT
CONTINUES TUESDAY BEFORE DIMINISHING TO SHOWERS TUESDAY AFTERNOON.
&&
.MARINE...AS OF 9:23 PM PST MONDAY...RAIN WILL BECOME MODERATE TO
HEAVY TONIGHT AND EARLY TUESDAY MORNING AS A COLD FRONT MOVES EAST
OVER THE COASTAL WATERS. WESTERLY SWELLS WILL INCREASE TUESDAY AND
WEDNESDAY WITH LARGER SWELL EXPECTED LATE WEDNESDAY NIGHT THROUGH
THURSDAY. ANOTHER COLD FRONT WILL SWING EAST OVER THE AREA LATE
TUESDAY NIGHT AND WEDNESDAY MORNING WITH MORE RAIN. WINDS AND SEAS
WILL DIMINISH LATE THIS WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...HIGH SURF ADVISORY...ALL COASTAL ZONES
FLASH FLOOD WATCH...BIG SUR COAST AND SANTA LUCIA MTNS.
SCA...SF BAY UNTIL 9 AM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 9 AM
SCA...PT REYES TO PIGEON PT 0-10 NM UNTIL 9 AM
SCA...PIGEON PT TO PT PINOS 0-10 NM UNTIL 9 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 9 AM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 9 AM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 9 AM
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
&&
$$
PUBLIC FORECAST: RWW/BELL
AVIATION: CANEPA
MARINE: CANEPA
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AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1255 AM MST TUE JAN 5 2016
.UPDATE...
ISSUED AT 1251 AM MST TUE JAN 5 2016
WEBCAMS SHOW ACCUMULATING SNOW FOR OUR SOUTHERN VALLEYS THIS
MORNING AND AFTER SOME CALLS TO LOCAL LAW ENFORCEMENT...FELT IT
PRUDENT TO ISSUE ADVISORIES FOR SE UT AND ALL SRN CO VALLEYS.
RAP13 AND HRRR ALSO SHOW SNOW CONTINUING THROUGH THE MORNING HOURS
AND ARE HANDLING CURRENT SNOW WELL. SOME AREAS WILL SEE LITTLE
ACCUMULATION WHILE OTHERS WILL LIKELY SEE 1 TO 3 INCHES WITH
POSSIBLY HIGHER AMOUNTS AT HIGHER ELEVATIONS. WHILE THESE AMOUNTS
ARE SUB- ADVISORY CRITERIA...THE MORNING COMMUTE WILL BE A MESS
WITH SNOW AND ICY COVERED ROADS ANTICIPATED. THE ADVISORY LASTS
THROUGH 10AM THIS MORNING AND CAN BE PULLED DOWN EARLY IF
REQUIRED. UPPED SNOW AMTS AND POPS THROUGH THIS MORNING.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 352 PM MST MON JAN 4 2016
TEMPERATURES TODAY HAVE SKYROCKETED AS WARM AIR ADVECTS INTO THE
FOUR CORNERS REGION. THE MOUNTAIN AND VALLEY TEMPERATURES ARE MUCH
MORE ISOTHERMAL THIS AFTERNOON THAN THEY HAVE BEEN RECENTLY
THANKS TO MIXING OF THIS WARMER AIR INTO SOME OF THE LOWER
VALLEYS. THE NOTABLE EXCEPTIONS ARE VERNAL AND GUNNISON WHERE
THEIR MAX TEMPS ARE STILL LINGERING IN THE SINGLE DIGITS TO TEENS.
CURRENT SATELLITE AND RADAR IMAGERY COMBINED WITH OBS INDICATE
DEEPEST MOISTURE OVER CENTRAL ARIZONA HEADED THIS WAY. THE
LOWERING OF THE CLOUD DECK IS EVIDENT AT THE BLANDING ASOS...AND
THIS TREND WILL CONTINUE THROUGHOUT THE EVENING. THE BEST CHANCE
OF PRECIPITATION ACROSS SE UTAH AND SW COLORADO WILL BE BETWEEN
10PM AND EARLY TUESDAY MORNING AS A COUPLE OF H5 VORT LOBES HELP
TO ORGANIZE SHOWER ACTIVITY AS THEY STREAM NORTH INTO THE FOUR
CORNERS REGION. EXPECTING A FEW SHOWERS MAINLY ABOVE 7000 FEET
ELSEWHERE BUT MOST LOWER VALLEYS NORTH OF THE SAN JUANS WILL
REMAIN DRY. GENERALLY AN INCH OF SNOW IS EXPECTED ALONG THE
VALLEYS OF SE UTAH AND SW COLORADO WITH CLOSER TO 2 TO 4 INCHES
POSSIBLE ALONG THE SOUTH-FACING AREA OF THE SOUTHERN SAN JUANS AND
ABAJOS. THE PRECIPITATION WHICH FALLS ACROSS VALLEYS OF SE UTAH
TONIGHT BELOW 5500 FEET MAY BEGIN TO MELT AROUND THAT ELEVATION BEFORE
IT REACHES THE GROUND BUT IS EXPECTED TO REMAIN AS FROZEN
PRECIPITATION.
RELATIVELY MOIST AND MILD AIR MASS WILL BE OVERRIDING COLD SURFACE
TEMPERATURES ON TUESDAY MORNING AS PACIFIC SHORT WAVE LIFTS
NORTHEAST OVER THE WESTERN SLOPE ON TUESDAY. EXAMINING WET BULB
TEMPERATURES IN THE 1 KM LAYER ABOVE THE SURFACE SUGGEST THAT
PRECIPITATION TYPE MIGHT BE RAIN. IF RAIN DOES OCCUR...THEN SPOTTY
FREEZING RAIN IS A POSSIBILITY IN THE LOWER VALLEYS (BELOW 5000
FEET) GIVEN SUB FREEZING TEMPS ARE LIKELY. I THINK THIS IS AN
UNLIKELY SCENARIO AS MODEL DATA MAY NOT HAVE THE BEST HANDLE ON
SNOW COVERED SURFACE CONDITIONS...THE COLD BOUNDARY LAYER IS
LIKELY DEEPER THAN WHAT MODEL DATA SHOWS. HOWEVER IT IS WORTH
MENTIONING THIS OUTCOME SINCE FREEZING RAIN IS RARE...BUT LIGHT
SNOW IS THE LIKELY SCENARIO IF PRECIPITATION OCCURS IN THE LOWER
VALLEYS.
PRECIPITATION...MOSTLY SNOW...WILL BE FOCUSED OVER THE SOUTHERN
HALF AS THE SHORT WAVE WILL BE WEAKENING AS IT REACHES THE
NORTHERN AREAS. THIS TREND LASTS INTO TUES EVENING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 PM MST MON JAN 4 2016
THERE WILL BE A LULL IN THE ACTIVITY TUES AFTERNOON/EVENING...BUT
THE NEXT STRONGER PACIFIC WAVE MOVES ACROSS THE REGION LATE
TUES NIGHT INTO WED EVENING. AIR MASS WILL BE MOIST WITH DECREASING
STABILITY GIVEN THE MID LEVEL COLD ADVECTION. SURPRISINGLY...THE
IN HOUSE LIGHTNING POTENTIAL SHOWS POCKETS OF INSTABILITY PER NAM
MODEL...AND THE DAY 3 CONVECTIVE OUTLOOK SHOWS THUNDER POTENTIAL
FOR THE LOWER ELEVATIONS OF THE FORECAST AREA. TYPICALLY THUNDER
DOES NOT OCCUR WHEN THE DESERT VALLEYS HAVE SNOW ON THE GROUND.
HOWEVER ITS NOT UNUSUAL FOR MOIST PACIFIC WAVES TO TRIGGER STORMS
ASSOCIATED WITH THE TROUGH AXIS PASSAGE. REGARDING WINTER
WEATHER...MODERATE SNOW ACCUMULATIONS ARE LIKELY OVER THE SAN JUAN
MOUNTAINS AND WINTER WEATHER ADVISORIES MAY BE NECESSARY FOR
SOUTHWEST COLORADO...POSSIBLY EXTENDING AS FAR NORTH AS THE GRAND
MESA.
THE FORECAST CONFIDENCE DIMINISHES DURING THE LATTER PART OF THE
WEEK. THE MEDIUM RANGE MODELS ARE SHOWING A LACK OF CLARITY
REGARDING HOW MUCH POLAR INFLUENCE REACHES THE INTERIOR WEST AND
THE CENTRAL ROCKIES. BROAD TROUGH WILL BE POSITIONED OVER THE
CENTRAL CONUS...BUT SOME PACIFIC MOISTURE MAY BE ENTRAINED INTO
THE NORTHWEST FLOW. THE 12Z MODEL GUIDANCE DOWNPLAYED THIS
POTENTIAL. CONSENSUS POPS SHOW 20-30 PERCENT POPS FOR THE WESTERN
SLOPES MOUNTAINS FROM FRIDAY THROUGH SUNDAY TIME FRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 957 PM MST MON JAN 4 2016
LIGHT SNOW HAS DEVELOPED OVER THE SOUTHERN VALLEYS AND HILLS OF
UTAH AND SOUTHWEST COLORADO THIS EVENING. PROBABILITIES ARE HIGH
THAT KDRO WILL BE IMPACTED BY IFR CONDITIONS FOR AN EXTENDED
PERIOD OVERNIGHT INTO TUESDAY MORNING. KTEX WILL BE ALSO BE
IMPACTED BY LOW MVFR CIGS THROUGH 10Z THEN SNOW COULD SETTLE IN
AND BRING IFR CONDITIONS THROUGH THE MORNING HOURS. KCNY AND KVEL
COULD BE IMPACTED FROM SOME LIGHT FOG AND BRING MVFR CONDITIONS
BUT PROBABILITIES AND CONFIDENCE LOW. THE REMAINING TERMINAL
FORECAST SITES ARE EXPECTED TO HAVE VFR CONDITIONS PREVAIL THOUGH
ILS BREAK POINTS MAY BE EXCEEDED AS CIGS LOWER THROUGH SUNRISE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 10 AM MST THIS MORNING FOR
COZ021>023.
UT...WINTER WEATHER ADVISORY UNTIL 10 AM MST THIS MORNING FOR UTZ022-
028.
&&
$$
UPDATE...TGR
SHORT TERM...JAM/PF
LONG TERM...PF
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
112 AM EST TUE JAN 5 2016
.SYNOPSIS...
CANADIAN HIGH PRESSURE BUILDS OVER THE AREA THROUGH TUESDAY...THEN
BUILDS TO THE SOUTH TUESDAY NIGHT THROUGH THURSDAY. ANOTHER AREA
OF HIGH PRESSURE BUILDS TO THE NORTH THURSDAY NIGHT AND
FRIDAY...RETREATING TO THE CANADIAN MARITIMES FRIDAY NIGHT AND
SATURDAY. AN UNSETTLED WEATHER PATTERN LOOKS IN STORE FOR THE AREA
OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
700-300 HPA TROUGH AXIS SWINGS THROUGH INTO THE EARLY MORNING
HOURS...THEN DEEP LAYERED RIDGING BEGINS TO BUILD IN TOWARDS
MORNING. ANY LINGERING STRATO-CUMULUS SHOULD DISSIPATE AS THE
TROUGH AXIS SLIDES TO THE EAST/RIDGING BEGINS TO BUILD IN. STILL
ON TRACK FOR CLEAR SKY CONDITIONS OVERNIGHT.
COLD AIR ADVECTION AND A TIGHT PRESSURE GRADIENT WILL RESULT IN A
CONTINUATION OF GUSTY WINDS AND PLUMMETING TEMPS. AFTER RECORD
WARMTH FOR NOVEMBER AND DECEMBER...THE COLDEST NIGHT OF THE SEASON
IS ANTICIPATED. WITH COLD BEING LIMITED BY STRENGTH OF WIND TO
WHAT COLD ADVECTION BRINGS IN. NOTING ALREADY TEMPERATURES UNDER
CUTTING FORECAST BY 2-4 DEGREES AT MANY LOCATIONS. HAVE UPDATED
USING A BLEND OF THE LOWEST VALUE OF LAV/MAV/MET GUIDANCE AND NAM
AND HRRR 2-METER TEMPERATURES AND THOSE INDIVIDUAL CONSTITUENTS.
THE BLEND WAS WEIGHED TOWARDS THE COLDEST VALUE AT ANY GIVEN
POINT. LOWS GENERALLY 10-15 NEAR THE COAST...EXCEPT UPPER TEENS
EASTERN TWIN FORKS OF LONG ISLAND...AND SINGLE DIGITS ELSEWHERE.
ALSO...WINDS RUNNING A TAD STRONGER THAN PREVIOUSLY FORECAST...SO
IMPACT OF GUSTY NORTH WINDS WITH A SLIGHTLY COLDER TEMPERATURE
FORECASTS...WILL PRODUCE WIND CHILLS SLIGHTLY COLDER THAN
PREVIOUSLY FORECAST AT MOST LOCATIONS. WIND CHILL VALUES
OVERNIGHT WILL RUN AROUND ZERO TO 5 BELOW ACROSS NYC/LONG ISLAND
AND 5 TO 10 BELOW ELSEWHERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
RIDGE BUILDS THIS TIME FRAME BEHIND THE DEPARTING TROUGH.
SUBSIDENCE WILL ENSURE CLEAR SKIES THROUGH WED.
AS THE CENTER OF HIGH PRESSURE NEARS...ANY RESIDUAL GUSTS
WILL DIMINISH TUESDAY...AND WINDS REMAIN LIGHT OR CALM TUESDAY NIGHT.
A VERY COLD START TO THE DAY IS EXPECTED...AND TEMPS REMAIN QUITE
CHILLY TUESDAY...REMAINING BELOW FREEZING FOR THE MOST PART ACROSS
THE CWA.
AT NIGHT...TEMP FORECAST IS A BIT MORE CHALLENGING. WARM AIR
ADVECTION WILL BE UNDERWAY...BUT CLEAR SKIES AND LIGHT WINDS WILL
PROMOTE RADIATIONAL COOLING. THERE IS A TEMP DISPARITY IN THE MOS
GUIDANCE...AND AMONG ENSEMBLE GUIDANCE. WILL NOT STRAY TOO FAR
FROM PREVIOUS FORECAST...TAKING A BLEND OF AVAILABLE GUIDANCE BUT
SIDING ON THE LOWER END OF THE SPREAD.
TEMPS MODIFY ON WEDNESDAY AS THE CENTER OF THE HIGH PASSES TO THE
SOUTH AND RETURN FLOW W/SW WINDS PREVAIL.
TEMPS LIKELY RISE CLOSE TO IF NOT JUST ABOVE SEASONAL NORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE H5 FLOW IS IN GOOD AGREEMENT THROUGH FRI...BUT THEN DIFFERENCES
BEGIN TO TAKE SHAPE FROM THE INTERACTION BETWEEN A LARGE CANADIAN
VORTEX OVER HUDSON BAY AND A CUTOFF LOW PRES SYSTEM MOVING ONSHORE
OUT WEST. THE 12Z MODELS SEEM TO BE IN SOMEWHAT BETTER AGREEMENT
THAN THE 00Z RUNS WITH THE OVERALL PATTERN...THAT BEING THE
ELONGATED E-W ORIENTED VORTEX BECOMING N-S ORIENTED WITH A COLDER
AIRMASS DIVING INTO THE NORTHERN PLAINS/UPPER MIDWEST/GREAT LAKES
FOR THE WEEKEND. THIS VORTEX WILL THEN MEANDER ABOUT ERN ONTARIO
THROUGH THE MIDDLE OF NEXT WEEK.
IN TERMS OF SENSIBLE WEATHER...DRY AND NEAR TO SLIGHTLY ABOVE NORMAL
TEMPERATURES THROUGH FRI WITH HIGH PRES IN CONTROL. WARM AIR
ADVECTION RAINS MOVE INTO THE AREA FRI NIGHT THROUGH
SAT...ALTHOUGH THE RETREATING HIGH TO THE NORTH WILL RESULT IN
COLD AIR DAMMING WITH A POSSIBILITY OF A WINTRY MIX OF
PRECIPITATION ACROSS THE INTERIOR TO START. SHOULD TURN TO PLAIN
RAIN AT ALL LOCATIONS BY SAT AFTERNOON. THE AMOUNT OF QPF REMAINS
IN QUESTIONS AS THERE IS THE POTENTIAL FOR A WAVE OF LOW PRES TO
DEVELOP OFF THE MID ATLANTIC COAST AND PASS SOUTH OF LONG ISLAND
ON SAT. HAVE KEPT LOW CHANCE POPS IN THE FORECAST SAT NIGHT INTO
SUN...ALTHOUGH WE MAY END UP SEEING A LULL IN PRECIPITATION BEFORE
THE NEXT POTENTIAL SYSTEM TRACKS UP FROM THE S. THIS SYSTEM
CURRENTLY LOOKS WARM ENOUGH FOR ALL RAIN...BUT IF THE UPPER
PATTERN CHANGES AND THE STORM SHIFTS A BIT FURTHER OFFSHORE...IT
P-TYPE COULD BE MIXED OR IN SOLID FORM. WEAK HIGH PRES RETURNS FOR
MONDAY.
TEMPS ARE EXPECTED TO BE ABOVE NORMAL LEVELS THROUGH THE REMAINDER
OF THE PERIOD.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
HIGH PRESSURE CENTERED OVER THE GREAT LAKES REGION BUILDS SLOWLY
OVER THE TERMINALS THROUGH 00Z WEDNESDAY...THEN REMAINS ALONG THE
MID ATLANTIC COAST INTO WEDNESDAY MORNING.
VFR THROUGH THE TAF PERIOD...WITH A SCATTERED TO BROKEN DECK 5 TO 6K
FT TIL 08Z TO 09Z...FROM THE NYC TERMINALS EAST. OTHERWISE
CLEAR.
NORTH WINDS SUSTAINED 15 TO 20 KT WITH GUSTS 25 TO 30 KT UNTIL
AROUND 10Z WITH SUSTAINED WINDS AND GUSTS SLOWLY DIMINISHING.
GUSTS ARE EXPECTED TO END 14Z TO 17Z. WINDS BACK TO NORTHWEST DURING
THE AFTERNOON...REMAINING MAINLY TO THE RIGHT OF 310 TRUE,,,THEN
BECOME MORE WESTERLY AFTER 02Z WEDNESDAY.
.OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...
.LATE TUESDAY NIGHT-FRIDAY...VFR.
.FRIDAY NIGHT...MVFR OR LOWER LIKELY...IN RAIN...WITH A WINTRY MIX
POSSIBLE AT KSWF. E WINDS G15-20KT POSSIBLE.
.SATURDAY...MVFR OR LESS LIKELY IN RAIN.
&&
.MARINE...
WIND GUSTS RUNNING HIGHER THAN EXPECTED. WITH LOW LEVEL WINDS
FORECAST TO INCREASE INTO THE OVERNIGHT HOURS...BEFORE DIMINISHING
TOWARDS SUNRISE...HAVE ISSUED A GALE WARNING FOR ALL WATERS
THROUGH 12Z.
THE WINDS WILL DECREASE ON TUESDAY AS THE PRESSURE GRADIENT
SLACKENS OVER THE REGION. WOULD EXPECT GUSTS TO 25-30 KT TO
CONTINUE OVER THE OCEAN WATERS/BAYS OF LONG ISLAND/EASTERN SOUND
INTO THE MORNING HOURS. SEAS SHOULD REMAIN ABOVE SCA LEVELS ON THE
COASTAL OCEAN WATERS INTO TUESDAY AFTERNOON...DEPENDING ON EXACTLY
HOW QUICKLY THE WINDS SUBSIDE.
TRANQUIL CONDITIONS ARE ANTICIPATED LATE TUESDAY THROUGH
WEDNESDAY.
SUB-ADVISORY CONDITIONS PREVAIL WED NIGHT THROUGH FRIDAY WITH A
WEAK PRES GRADIENT OVER THE AREA. WINDS AND SEAS WILL INCREASE FRI
NIGHT IN RESPONSE TO AN STRENGTHENING EASTERLY FLOW. WINDS SHOULD
SUBSIDE ON SAT...BUT SEAS ON THE OCEAN WILL LIKELY LINGER.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS FORECAST THROUGH FRIDAY. THE NEXT
CHANCE FOR RAIN IS FRIDAY NIGHT CONTINUING THROUGH SATURDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...GALE WARNING UNTIL 7 AM EST THIS MORNING FOR ANZ330-335-338-
340-345-350-353-355.
&&
$$
SYNOPSIS...24/MALOIT/PW
NEAR TERM...MALOIT/PW/DW
SHORT TERM...PW
LONG TERM...24
AVIATION...MET/DW
MARINE...24/MALOIT/PW
HYDROLOGY...24/PW
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
349 PM EST TUE JAN 5 2016
...HAZARDOUS CONDITIONS FOR SMALL CRAFT PERSIST THROUGH
TONIGHT...
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A CURRENTLY LESS
AMPLIFIED UPPER LEVEL PATTERN ACROSS THE CONUS. MAIN EAST COAST
LONGWAVE TROUGH IS QUICKLY EXITING THE NORTHEAST COAST INTO THE
WESTERN ATLANTIC...WITH A BROAD REGION OF UPPER RIDGING SPRAWLING
ACROSS THE EASTERN CONUS IN ITS WAKE. OUR FORECAST AREA RESIDES
WITHIN A DEEP LAYER OF MID/UPPER LEVEL SOUTHWESTERLY WINDS
UNDERNEATH THE SOUTHERN STREAM FLOW. WITHIN THIS SOUTHERN STREAM
WE ARE WATCHING A HEALTHY SHORTWAVE TROUGH WHICH HAS EJECTED FROM
NORTHERN MEXICO AND IS NOW CROSSING THE WESTERN GULF OF MEXICO. WV
IMAGERY CONTINUES TO SHOWS AN INCREASING PLUME OF MID/HIGH LEVEL
MOISTURE STREAMING OUT AHEAD OF THIS ENERGY OVER THE EASTERN GULF
AND FLORIDA PENINSULA. THIS SHORTWAVE WILL BECOME BETTER ORGANIZED
PER GFS/ECMWF AS IT CROSSES THE GULF DURING THE NEXT 12-18
HOURS...AND WILL CAUSE OUR FORECAST TO BECOME A BIT TRICKY LATE
TONIGHT INTO WEDNESDAY...ESPECIALLY THE FURTHER SOUTH AND
SOUTHEAST FROM THE I-4 CORRIDOR ONE TRAVELS.
AT THE SURFACE...OUR WEATHER IS DOMINATED BY STRONG HIGH PRESSURE
CENTERED OVER THE MID-ATLANTIC STATES...BUT RIDGING ALL THE WAY
SOUTH TO THE FL PENINSULA/EASTERN GULF OF MEXICO. THE TIGHT
GRADIENT ON THE SOUTHERN PERIPHERY OF THIS RIDGE ALONG WITH
RESIDUAL COLD AIR ADVECTION (CAA) HAS THE WINDS REALLY RAMPED UP
OVER THE EASTERN GULF OF MEXICO...WHERE SMALL CRAFT ADVISORIES
REMAIN IN EFFECT THROUGH THE OVERNIGHT.
THE TROP DRIED OUT SIGNIFICANTLY BETWEEN MONDAY MORNING AND
THIS MORNING...WITH THE 12Z KTBW SOUNDING SAMPLING A PW VALUE OF
ONLY 0.44". THIS VALUE IS RIGHT ABOUT AT THE 10TH PERCENTILE FOR
EARLY JANUARY. HOWEVER...THE DRYING OF THE COLUMN ENDED EARLIER
TODAY...AND WE HAVE BEGUN A GRADUAL MOISTENING THAT WILL WORK ITS
WAY SLOWLY SOUTH TO NORTH. CROSS SECTION ANALYSIS FROM ALL
RELIABLE GUIDANCE SHOW THIS TREND OF A GENERAL ERODING OF THE
DRIEST LAYER ABOVE THE SURFACE THROUGH THE OVERNIGHT...WITH THE
PROCESS QUICKEST AND MOST DRAMATIC OVER THE SOUTHERN HALF OF THE
PENINSULA.
AT LEAST THROUGH THE EVENING HOURS...THE DRY AIR ALOFT WILL WIN
ACROSS OUR FORECAST ZONES...AND HAVE NO MEASURABLE RAIN MENTIONED
IN THE FORECAST. IT WOULD NOT BE IMPOSSIBLE TO SEE A FEW
SPRINKLES WORK AS FAR NORTH AS LEE/CHARLOTTE AND HIGHLANDS
COUNTIES...BUT SHOULD NOT BE IMPACTFUL FOR OUTDOOR ACTIVITIES.
THE TIGHT GRADIENT WILL KEEP CONDITIONS RATHER BREEZY THROUGH THE
EARLY EVENING HOURS WITH SEASONABLY COOL TEMPERATURES. HIGH TEMPS
THIS AFTERNOON HAVE REACHED CLOSE TO 60 OVER THE FAR NORTH...TO
THE MIDDLE 60S THROUGH THE I-4 CORRIDOR...AND TO WITHIN A COUPLE
DEGREES OF 70 OVER THE SOUTHERN ZONES. HIGH TEMPS SHOULD NOW HAVE
BEEN REACHED AND WILL SEE THESE READINGS BEGIN TO SLIDE BACK DOWN
IN THE COMING FEW HOURS.
&&
.SHORT TERM (TONIGHT THROUGH WEDNESDAY)...
LATER TONIGHT INTO WEDNESDAY IS WHEN THE FORECAST STARTS TO BECOME
A LITTLE MORE TRICKY. THE GOOD NEWS COMPARED TO THE FORECAST
SCENARIO EARLIER TODAY IS THAT THE 12Z NAM HAS COME AROUND CLOSER
TO RECENT GFS/ECMWF SOLUTIONS...WHEN COMPARED TO ITS PREVIOUS 06Z
RUN...WHICH WAS CONSIDERABLY WETTER FOR WEDNESDAY SOUTH OF THE I-4
CORRIDOR. AT LEAST THIS TREND ADDS SOME FORECAST CONFIDENCE THAT
WAS MORE IN QUESTION EARLIER.
SHORTWAVE ENERGY WILL BE MIGRATING TOWARD THE REGION
OVERNIGHT/EARLY WEDNESDAY WITH INCREASING SYNOPTIC SUPPORT/DEEP
LAYER Q-VECTOR CONVERGENCE OVERSPREADING THE REGION IN ADVANCE.
RATHER IMPRESSIVE COUPLING OF LEFT EXIT REGION AND RIGHT ENTRANCE
REGION OF PAIRED UPPER JETS WILL ALSO BE TAKING PLACE. WHILE THE
DEEP LAYER HEIGHT FALLS/Q-VECTOR CONVERGENCE IS BROAD ENOUGH TO
ENCOMPASS MUCH OF THE REGION...THE BEST JET COUPLING AND
RESULTING UPPER DIVERGENCE FIELDS COINCIDENT WITH THE HEIGHT
FALLS ARE SHOWN TO MAXIMIZE OVER THE FAR SOUTHERN FL
PENINSULA/FLORIDA STRAITS AND BAHAMAS. IT WILL BE THIS AREA WHERE
IT IS AGREED UPON IN THE NWP GUIDANCE THAT WE WILL SEE SURFACE
CYCLOGENESIS COMMENCE OVERNIGHT AND LIFT NORTHEASTWARD WEDNESDAY
AND WEDNESDAY NIGHT. WITH THE LOW DEVELOPING IN THIS AREA...THE
STRONGEST AND MOST EFFICIENT LOWER LEVEL FRONTOGENESIS ALSO STAYS
JUST TO THE SOUTH AND SOUTHEAST OF OUR ZONES. AT LEAST IN THE
LOWER LEVELS...THIS PLACEMENT WOULD RESULT IN OUR SOUTHERN ZONES
RESIDING WITH A ZONE OF GENERAL SUPPRESSION (DESCENDING AIR) ON
THE COLD SIDE OF THE FRONTAL THERMAL CIRCULATION.
ALL THIS BEGIN SAID...WILL BE A VERY CLOSE CALL BETWEEN OUR FAR
SOUTHERN AND INTERIOR SOUTHERN ZONES
(HIGHLANDS/DESOTO/CHARLOTTE/LEE) AND THE NORTHERN EXTENT OF THE
POTENTIALLY ORGANIZED RAINFALL ZONE LATE TONIGHT INTO WEDNESDAY.
AS MENTIONED ABOVE...THE GFS/ECMWF HAVE BEEN CONSISTENT IN KEEPING
THE BEST LIFT AND MOST ORGANIZED SHOWER ACTIVITY GENERALLY OUT OF
OUR AREA FOR SEVERAL PAST MODEL RUNS. LOOKING AT THE INDIVIDUAL
GEFS MEMBERS...MOST ALSO KEEP SIGNIFICANT PRECIP SOUTH OF OUR
AREA...AND THE STANDARD DEVIATION OF PRECIP AMOUNTS AMONG THE
MEMBERS IS LESS THAN 1/10TH OF AN INCH OVER THE SOUTHERN ZONES.
THIS LOW A VALUE TENDS TO SUGGEST HIGHER CONFIDENCE IN THE MEAN
ENSEMBLE VALUES. THE NAM WHILE STILL FURTHER WEST AND NORTHWEST
WITH ITS LIFT AND RESULTING QPF FIELDS...HAS TRENDED
BACK/DRIER/LESS LIFT OVER OUR AREA FROM EARLIER SOLUTIONS.
FINALLY...AT LEAST WORTH A MENTION...TOOK A QUICK LOOK AT THE
05/00Z RUN OF THE PARALLEL NEXT GENERATION GFS CURRENTLY BEING
TESTED...AND IT WAS VERY SIMILAR TO THE PAST FEW OPERATIONAL GFS
RUNS. WILL HAVE TO KEEP SOME SHOWER CHANCES IN THE FORECAST BASED
ON THE INCREASINGLY FAVORABLE MOISTURE PROFILES...AND OVERALL
PRESENCE OF WEAK SYNOPTIC LIFT...BUT FEELING IS THAT A WASHOUT
FOR THESE SOUTHERN ZONES ON WEDNESDAY IS UNLIKELY. FURTHER NORTH
TOWARD TAMPA BAY AND NATURE COAST ZONES...JUST MENTIONING A FEW
SPRINKLES ON WEDNESDAY. MANY LOCATIONS ALONG AND NORTH OF THE I-4
CORRIDOR ARE LIKELY TO NOT EVEN SEE MEASURABLE PRECIP.
GIVEN THE SYSTEM PASSING OVERHEAD...WILL SEE A MOSTLY CLOUDY DAY
FOR MOST LOCATIONS WEDNESDAY...HOWEVER HIGH TEMPERATURES SHOULD
BE UP SEVERAL DEGREES FROM WHAT WE ARE SEEING THIS AFTERNOON.
&&
.LONG TERM (THURSDAY THROUGH NEXT TUESDAY...
TEMPERATURES TO START THE MID/LONG TERM PERIOD WILL BE ABOVE
CLIMATOLOGICAL NORMS AS THEY CONTINUE TO REBOUND FROM THE COOLER
TEMPERATURES WE SAW TO START THIS WEEK. ON THURSDAY A SHORTWAVE WILL
MOVE INTO THE SOUTHERN TENNESSEE VALLEY AS IT EXITS THE SOUTHERN
PLAIN STATES. MODELS CONTINUE TO DISAGREE ON THE INTENSITY OF THE
NEXT SYSTEM WHICH WILL APPROACH THE AREA LATE ON THURSDAY INTO
FRIDAY. 12Z ECMWF REMAINS MORE ROBUST COMPARED TO THE GFS. THAT
BEING SAID...WITH AMPLE MOISTURE IN PLACE AND UPPER LEVEL FORCING IN
THE FORM OF A ~120 KNOT SOUTHERN STREAM JET OVERHEAD SEEMS LIKELY WE
WILL SEE SOME SHOWER ACTIVITY ACROSS THE AREA ON FRIDAY. IF THE
ECMWF SOLUTION TURNS OUT TO BE CORRECT POPS WILL LIKELY NEED TO
BE RAISED QUITE A BIT BUT FOR NOW GIVEN LACK OF AGREEMENT WONT GO
TOO ROBUST WITH RAIN CHANCES.
AFTER THIS SYSTEM PUSHES AWAY FROM THE AREA...YET ANOTHER SOUTHERN
STREAM SYSTEM LOOKS TO APPROACH THE STATE OVER THE WEEKEND WITH
ANOTHER DECENT OPPORTUNITY FOR RAINFALL. COOLER AND DRIER AIR LOOKS
TO MOVE IN BEHIND THIS SYSTEM HOWEVER. THIS AIRMASS LOOKS SIMILAR TO
THE ONE THAT JUST MOVED IN A FEW DAYS AGO SO HIGHS WILL LIKELY TOP
OUT IN THE 60S ACROSS THE AREA TO START NEXT WEEK WITH LOWS IN THE
40S AND 50S.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST
FLORIDA THROUGH THE EVENING HOURS. THE MAIN AVIATION CONCERN WILL
BE CONTINUED GUSTY NORTHEASTERLY WINDS FOR THE NEXT SEVERAL HOURS
WHICH WILL GUST AT TIMES IN EXCESS OF 20 KNOTS. THE WIND WILL
BECOME LESS GUSTY WITH THE SETTING OF THE SUN THIS
EVENING...ESPECIALLY AWAY FROM THE IMMEDIATE COAST. MORE IN THE
WAY OF CLOUDS FOR WEDNESDAY WITH A FEW SHOWERS POSSIBLE FROM KPGD
TO KFMY/KRSW...HOWEVER ANTICIPATING VFR THROUGH END OF TAF PERIOD.
&&
.MARINE...
...SMALL CRAFT ADVISORY IN EFFECT UNTIL 10 AM EST WEDNESDAY FOR
OFFSHORE WATERS FROM 20 TO 60 NM EXTENDING FROM BONITA BEACH TO
THE SUWANNEE RIVER...
...SMALL CRAFT ADVISORY IN EFFECT UNTIL 10 AM EST WEDNESDAY FOR
NEAR SHORE WATERS OUT TO 20 NM EXTENDING FROM TARPON SPRINGS TO
THE SUWANNEE RIVER...
...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 AM EST WEDNESDAY FOR
NEAR SHORE WATERS OUT TO 20 NM EXTENDING FROM BONITA BEACH TO THE
TARPON SPRINGS...THE WATERS OF TAMPA BAY...AND CHARLOTTE
HARBOR...
STRONG HIGH PRESSURE WILL REMAIN CENTERED TO THE NORTH OF THE
REGION THROUGH WEDNESDAY. ELEVATED NORTHEASTERLY WINDS AND
ELEVATED SEAS WILL KEEP CONDITIONS AT OR NEAR ADVISORY LEVELS
THROUGH TONIGHT. WINDS AND SEAS ARE EXPECTED TO RELAX BELOW
HEADLINE CRITERIA LATER IN THE WEEK...BUT AT THE SAME TIME...RAIN
CHANCES WILL BE INCREASING AS THE NEXT IN A SERIES OF SYSTEM
APPROACH FROM THE WEST BY FRIDAY.
&&
.FIRE WEATHER...
AFTER A BRIEF PERIOD OF DRY LOW LEVEL AIR...MOISTURE LEVELS ARE
ALREADY ON THE INCREASE...AND WILL CONTINUE TO INCREASE THROUGH
THE MID-WEEK PERIOD. RELATIVE HUMIDITY IS NOT EXPECTED TO DROP
BELOW CRITICAL LEVELS AGAIN DURING THE FORECAST PERIOD. WINDS
WILL HOWEVER REMAIN GUSTY THROUGH WEDNESDAY WITH ELEVATED
DISPERSION INDICES LATE WEDNESDAY MORNING AND WEDNESDAY
AFTERNOON.
FOG POTENTIAL...NO SIGNIFICANT AREA OF FOG OR REDUCED VISIBILITY
ARE EXPECTED THROUGH WEDNESDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 54 73 58 76 / 0 10 10 10
FMY 59 75 59 78 / 10 30 10 0
GIF 55 73 56 76 / 10 20 20 10
SRQ 56 74 58 75 / 0 10 10 0
BKV 50 71 53 75 / 10 10 10 10
SPG 57 73 60 74 / 0 10 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR COASTAL
WATERS FROM TARPON SPRINGS TO SUWANNEE RIVER FL OUT
20 NM-WATERS FROM BONITA BEACH TO ENGLEWOOD FL OUT 20
TO 60 NM-WATERS FROM ENGLEWOOD TO TARPON SPRINGS FL
OUT 20 TO 60 NM-WATERS FROM TARPON SPRINGS TO
SUWANNEE RIVER FL OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR
CHARLOTTE HARBOR AND PINE ISLAND SOUND-COASTAL WATERS
FROM BONITA BEACH TO ENGLEWOOD FL OUT 20 NM-COASTAL
WATERS FROM ENGLEWOOD TO TARPON SPRINGS FL OUT 20 NM-
TAMPA BAY WATERS.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX..MROCZKA
LONG TERM/DECISION SUPPORT...MCKAUGHAN
AREA FORECAST DISCUSSION
NWS MIAMI FL
122 PM EST TUE JAN 5 2016
.AVIATION...
...18Z TAF ISSUANCE...VFR CONDITIONS ARE FORECAST TO PREVAIL
THROUGH AT LEAST 06Z EXCEPT FOR A SLIM CHC OF PERIODS OF MVFR
CEILINGS MAINLY ALONG THE SE FL COAST. WITH A BROAD SURFACE LOW
OVER EASTERN CUBA AND CENTRAL BAHAMAS AND A RIDGE OF HIGH PRESSURE
OVER THE CENTRAL ATLANTIC TO FLORIDA PENINSULA...THE PRESSURE
GRADIENT OF 5MB EXIST FROM CENTRAL FLORIDA TO THE KEYS WILL
SUPPORT NORTHEAST SUSTAINED FLOW OF 12 TO 18 KNOTS WITH GUSTS
THROUGH 18Z WEDNESDAY...WIND SPEEDS NOT AS STRONG TERMINAL
APF...TMB AND OPF. MOISTURE WILL INCREASE WITH DISTURBANCE
APPROACHING FROM THE WEST. AS A RESULT...RAIN IS EXPECTED MAINLY
AFTER 12Z WEDNESDAY SOME MVFR VISIBILITY RESTRICTIONS ARE POSSIBLE
AFTER 12Z WEDNESDAY...LESS CHANCE OF RAIN FOR TERMINAL KAPF.
&&
.PREV DISCUSSION... /ISSUED 839 AM EST TUE JAN 5 2016/
UPDATE...
NE WIND SHIFT GRADUALLY SPREADING SOUTHEASTWARD ACROSS EAST COAST
AREAS THIS MRNG. ONCE WINDS SHIFT TO NE...TEMPERATURES WILL RISE
AROUND 10 DEGREES /FROM L60S TO L70S/...THEN LEVEL OFF THROUGH
MUCH OF THE DAY AS SHOWER COVERAGE GRADUALLY INCREASES. WILL BE
MONITORING RADAR TRENDS CLOSELY...FOR POSSIBLE NEED TO BOOST POPS
UP A BIT. FOR NOW...NO CHANGES WARRANTED.
PREV DISCUSSION... /ISSUED 653 AM EST TUE JAN 5 2016/
AVIATION...
VFR CONDITIONS ARE FORECAST TO PREVAIL THROUGH THE
FORECAST PERIOD EXCEPT FOR A SLIM CHC OF PERIODS OF MVFR CEILINGS
MAINLY ALONG THE SE FL COAST. BUT GIVEN CONFIDENCE ON THAT IS LOW IT
IS NOT CURRENTLY REFLECTED ON THE FORECAST AND WILL AMEND AS NEEDED
IF THIS BECOMES A CONCERN OR ADDRESS IN FUTURE UPDATES. SOMETHING
NOT PICKED UP BY SHORT TERM MOS GUIDANCE BUT PICKED UP BY HRRR AND A
COUPLE OF LOCAL MODEL RUNS IS A LAND BREEZE PARTICULARLY ALONG SE
COAST SITES FROM FLL NORTH THROUGH AROUND DAWN WHEN THE LOW LEVEL NE
FLOW KICKS IN. THIS IS IN LINE WITH CURRENT OBSERVATIONS SO
REFLECTED THE LAND BREEZE ON TAF FORECAST FOR SITES ALONG SE COAST
THE FIRST COUPLE OF HOURS OR SO OF THE FORECAST EARLY THIS MORNING.
BLUSTERY NE WINDS WILL DEVELOP BY MID TO LATE MORNING AT ALL SITES
AND CONTINUE INTO THE EVENING. SOME MOISTURE WILL STREAM NORTH FROM
THE SOUTH TODAY WARRANTING MENTION OF VCSH PARTICULARLY ALONG SE FL
SITES.
PREV DISCUSSION... /ISSUED 441 AM EST TUE JAN 5 2016/
DISCUSSION...
TODAY-WEDNESDAY...COOL START TO THE DAY ACROSS SOUTH FLORIDA WITH
TEMPERATURES RANGING FROM THE UPPER 40S ACROSS GLADES AND HENDRY, TO
THE LOW 50S ALONG THE GULF COAST AND UPPER 50S TO LOW 60S ALONG THE
EAST COAST METRO.
FT LAUDERDALE INTERNATIONAL HAS DROPPED TO 59F SO FAR THIS MORNING,
BREAKING THE OLD RECORD FOR LATEST BELOW 60F TEMP WHICH WAS
PREVIOUSLY 29 DEC 1986. MIAMI INTERNATIONAL CONTINUES TO HOVER
AROUND 60-61F, SO IT MAY ALSO DIP TO 59F OR BELOW THIS MORNING. THE
PREVIOUS RECORD FOR LATEST BELOW 60F TEMP AT MIAMI WAS 23 DEC 1994.
WEST PALM DIPPED TO 57F YESTERDAY MORNING ALSO SETTING A NEW RECORD
FOR LATEST BELOW 60F DAY.
RADAR ALREADY SHOWS LIGHT ECHOES OVER THE ATLANTIC AND EAST COAST,
THOUGH A LOT OF THIS IS LIKELY NOT YET REACHING THE GROUND. DEEPER
MOISTURE ASSOCIATED WITH THE FORMER BOUNDARY LIFTS BACK TO THE NORTH
AS ANOTHER SHORTWAVE SWINGS INTO THE STATE AND SPAWNS A WEAK AREA OF
LOW PRESSURE ALONG THE BOUNDARY OVER THE CENTRAL/NW BAHAMAS. RAIN
CHANCES WILL INCREASE ALONG THE EAST COAST AND FAR SOUTHERN
PENINSULA LATE THIS MORNING AS THIS MOISTURE COMES INTO THE REGION
ALONG WITH THE FORCING AHEAD OF THE TROUGH .
HOW MUCH RAIN WE SEE TONIGHT INTO WEDNESDAY WILL BE DEPENDENT ON
WHERE THE LOW ULTIMATELY FORMS AND WHERE BEST CONVERGENT BANDS END
UP. BUT IT LOOKS LIKE A WET PERIOD THROUGH WEDNESDAY AS THE STATE
ALSO WILL BE IN A FAVORABLE REGION BETWEEN THE DEPARTING AND
APPROACHING JETS. WILL HAVE TO MONITOR FOR A LOCALIZED POTENTIAL
FOCUS FOR HEAVY RAINFALL ALONG THE EAST COAST. COVERAGE AND
INTENSITY OF RAIN WILL DROP OFF INTO THE INTERIOR AND GULF COAST.
A FEW THUNDERSTORMS ARE POSSIBLE, MAINLY OVER THE GULF STREAM
STARTING LATE TONIGHT, WITH THE POSSIBILITY FOR A FEW CREEPING INTO
THE EAST COAST.
TEMPERATURES WILL REMAIN COOL TODAY IN THE LOW 70S WITH A FEW MID
70S POSSIBLE INTO WEDNESDAY ALONG THE EAST COAST AS EAST FLOW
COMPONENT INCREASES OF THE RELATIVELY WARM ATLANTIC WATERS. THIS
MORNING WILL BE THE COOLEST OF THE WEEK WITH TEMPERATURES
ONLY DROPPING INTO UPPER 50S-MID 60S THE NEXT TWO NIGHTS.
INCREASING ONSHORE WINDS ALONG THE ATLANTIC COAST WILL RESULT IN RIP
CURRENT FORMATION AT THE ATLANTIC BEACHES TUE-WED...AND A HIGH RISK
OF RIP CURRENTS IS FORECAST.
THURSDAY-WEEKEND...THE PROGRESSIVE AND UNSETTLED PATTERN CONTINUES
INTO THE UPCOMING WEEKEND AS THE JET STREAM REMAINS ACROSS THE
SOUTHERN TIER OF THE US.
UPPER LEVEL SHORTWAVE AND ASSOCIATED DEVELOPING SURFACE LOW OVER THE
BAHAMAS QUICKLY LIFT OUT TO THE NORTHEAST ON THURS, BRINGING IN A
BRIEF SHOT OF DRIER AIR AND LOW RAIN CHANCES.
THEN THE NEXT SHORTWAVE CROSSING THE SOUTHEASTERN US BRINGS A WEAK
SURFACE FRONT INTO THE STATE ALONG WITH A RETURN OF ADEQUATE, THOUGH
NOT VERY DEEP, MOISTURE. SCATTERED SHOWERS WILL BE IN THE FORECAST
ACROSS THE REGION FOR BOTH FRI AND SAT.
WHILE BOTH THE GFS AND ECMWF ARE IN REMARKABLY GOOD AGREEMENT FOR
THE LATE WEEKEND, THERE ARE SOME SLIGHT DIFFERENCES IN THE SURFACE
PATTERN. THE ECMWF IS A LITTLE STRONGER AND SLOWER WITH THE
REINFORCING FRONT THAN THE GFS AND DRIES THINGS OUT A LITTLE MORE
INTO MONDAY. OVERALL HOWEVER, BOTH SHOW SAT NIGHT INTO SUNDAY AS A
PERIOD OF ENHANCED PRECIP CHANCES THAT MAY LINGER INTO MONDAY FOR AT
LEAST THE SOUTHERN PARTS OF THE REGION.
TEMPS/HUMIDITY WILL MODERATE MID-LATE WEEK...INTO THE UPPER
70S/AROUND 80 FOR HIGHS AND 60S FOR LOWS. THIS WILL BE ABOVE NORMAL,
BUT NOWHERE NEAR THE WARMTH OF LATE DEC.
MARINE...
STRONG EAST-NORTHEAST WINDS 20-25KTS CONTINUE ACROSS BOTH GULF AND
ATLANTIC WATERS INTO WEDNESDAY. SEAS BUILD TO 4-6FT FOR THE OFFSHORE
GULF WATERS AND 9-11FT IN THE GULF STREAM LATER TODAY. HAVE EXTENDED
THE SMALL CRAFT ADVISORY FOR ALL THE WATERS, INCLUDING LAKE
OKEECHOBEE, THROUGH WEDNESDAY MORNING. HAZARDOUS CONDITIONS MAY
LINGER LONGER OVER THE ATLANTIC INTO LATE WEDNESDAY.
WINDS DIMINISH WED NIGHT AS AN AREA OF LOW PRESSURE DEVELOPS JUST TO
OUR SOUTHEAST AND DISRUPTS THE GRADIENT. WINDS BECOME LIGHT NW
BEHIND THE DEPARTING LOW INTO THURS AND THEN S-SW AHEAD OF ANOTHER
SYSTEM INTO FRI. SEAS WILL BE SLOWER TO SUBSIDE, AND HAZARDOUS SEAS
MAY LINGER IN THE GULF STREAM THROUGH FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 74 69 76 65 / 30 40 70 50
FORT LAUDERDALE 73 66 75 67 / 40 50 80 50
MIAMI 75 67 76 67 / 40 60 80 40
NAPLES 76 59 79 60 / 10 20 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR FLZ168-172-
173.
AM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR AMZ610-630-
650-651-670-671.
GM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR GMZ656-657-
676.
&&
$$
SHORT TERM...
LONG TERM....
AVIATION...
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1207 PM EST TUE JAN 5 2016
.UPDATE (REST OF TODAY THROUGH WEDNESDAY)...
17Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A CURRENTLY LESS
AMPLIFIED UPPER LEVEL PATTERN ACROSS THE CONUS. MAIN EAST COAST
LONGWAVE TROUGH IS QUICKLY EXITING THE NORTHEAST COAST INTO THE
WESTERN ATLANTIC...WITH A BROAD REGION OF UPPER RIDGING SPRAWLING
ACROSS THE EASTERN CONUS IN ITS WAKE. OUR FORECAST AREA RESIDES
WITHIN A DEEP LAYER OF MID/UPPER LEVEL SOUTHWESTERLY WINDS
UNDERNEATH THE SOUTHERN STREAM FLOW. WITHIN THIS SOUTHERN STREAM
WE ARE WATCHING A HEALTHY SHORTWAVE TROUGH EJECTING FROM NORTHERN
MEXICO OUT ACROSS THE WESTERN GULF OF MEXICO. WV IMAGERY SHOWS AN
INCREASING PLUME OF MID/HIGH LEVEL MOISTURE BEGINNING TO STREAM
OUT AHEAD OF THIS ENERGY OVER THE FLORIDA PENINSULA. THIS
SHORTWAVE WILL ACTUALLY BECOME BETTER ORGANIZED AS IT CROSSES THE
GULF DURING THE NEXT 12-18 HOURS...AND WILL CAUSE OUR FORECAST TO
BECOME A BIT TRICKY LATE TONIGHT INTO WEDNESDAY...ESPECIALLY THE
FURTHER SOUTH AND SOUTHEAST FROM THE I-4 CORRIDOR ONE TRAVELS.
AT THE SURFACE...OUR WEATHER IS DOMINATED BY STRONG HIGH PRESSURE
CENTERED OVER THE MID-ATLANTIC STATES...BUT RIDGING ALL THE WAY
SOUTH TO THE FL PENINSULA/EASTERN GULF OF MEXICO. THE TIGHT
GRADIENT ON THE SOUTHERN PERIPHERY OF THIS RIDGE ALONG WITH
RESIDUAL COLD AIR ADVECTION (CAA) HAS THE WINDS REALLY RAMPED UP
OVER THE EASTERN GULF OF MEXICO...WHERE SMALL CRAFT ADVISORIES
REMAIN IN EFFECT.
THE TROP DRIED OUT SIGNIFICANTLY DURING THE PAST 24 HOURS...WITH
THE 12Z KTBW SOUNDING SAMPLING A PW VALUE OF ONLY 0.44". THIS
VALUE IS RIGHT ABOUT AT THE 10TH PERCENTILE FOR EARLY JANUARY.
HOWEVER...THE DRYING IS OVER...AND NOW WE BEGIN A GRADUAL
MOISTENING OF THE COLUMN ONCE AGAIN FROM SOUTH TO NORTH. ALREADY
SEEING THE INCREASE IN HIGH LEVEL CIRRUS STREAMING OVER THE
REGION...BUT ALSO QUICKLY SEEING LOW LEVEL MOISTURE ADVECTING
NORTHWARD FROM SOUTH FLORIDA INTO OUR SOUTHERN ZONES. CROSS
SECTION ANALYSIS FROM ALL AVAILABLE GUIDANCE SHOW THIS GENERAL
ERODING OF THE DRIER LAYER ABOVE THE SURFACE...WITH THE PROCESS
QUICKEST AND MOST DRAMATIC OVER THE SOUTHERN HALF OF THE
PENINSULA.
AT LEAST THROUGH THE EVENING HOURS...THE DRY AIR WILL WIN OUT OVER
OUR ZONES AND HAVE NO RAIN MENTIONED IN THE FORECAST. LIKELY TO
SEE SOME SHOWERS DEVELOPING WITH THE MORE FAVORABLE MOISTURE
PROFILES AND ONSHORE FLOW ALONG THE FLORIDA EAST COAST...BUT WILL
BE TOUGH TO GET ANY MEASURABLE PRECIP INLAND ENOUGH TO REACH OUR
ZONES. THE TIGHT GRADIENT WILL KEEP CONDITIONS RATHER BREEZY
THROUGH THE AFTERNOON HOURS WITH SEASONABLY COOL TEMPERATURES
STILL IN PLACE. HIGH TEMPS THIS AFTERNOON RANGING FROM AROUND 60
FAR NORTH TO THE MIDDLE 60S I-4 CORRIDOR...AND WITHIN A COUPLE
DEGREES OF 70 OVER THE SOUTHERN ZONES.
LATER TONIGHT INTO WEDNESDAY IS WHEN THE FORECAST STARTS TO BECOME
A LITTLE MORE TRICKY. ALTHOUGH...THE GOOD NEWS IS THAT THE 12Z
NAM HAS COME AROUND CLOSER TO RECENT GFS/ECMWF SOLUTIONS COMPARED
TO ITS PREVIOUS 06Z RUN...WHICH WAS CONSIDERABLY WETTER FOR
WEDNESDAY SOUTH OF THE I-4 CORRIDOR. SOME FORECAST CONFIDENCE
ADDED THERE.
SHORTWAVE ENERGY WILL BE MIGRATING TOWARD THE REGION
OVERNIGHT/EARLY WEDNESDAY WITH INCREASING SYNOPTIC SUPPORT/DEEP
LAYER Q-VECTOR CONVERGENCE OVERSPREADING THE REGION IN ADVANCE.
RATHER IMPRESSIVE COUPLING OF LEFT EXIT REGION AND RIGHT ENTRANCE
REGION OF PAIRED UPPER JETS WILL ALSO BE TAKING PLACE. WHILE THE
DEEP LAYER HEIGHT FALLS/Q-VECTOR CONVERGENCE IS BROAD ENOUGH TO
ENCOMPASS MUCH OF THE REGION...THE BEST JET COUPLING AND
RESULTING UPPER DIVERGENCE FIELDS COINCIDENT WITH THE HEIGHT
FALLS ARE SHOWN TO MAXIMIZE OVER THE SOUTHERN FL PENINSULA/FLORIDA
STRAITS AND BAHAMAS. IT WILL BE THIS AREA WHERE IT IS AGREED UPON
IN THE NWP GUIDANCE THAT WE WILL SEE SURFACE CYCLOGENESIS COMMENCE
OVERNIGHT AND LIFT NORTHEASTWARD WEDNESDAY AND WEDNESDAY NIGHT.
WITH THE LOW DEVELOPING IN THIS AREA...THE STRONGEST AND MOST
EFFICIENT LOWER LEVEL FRONTOGENESIS ALSO STAYS JUST TO THE SOUTH
AND SOUTHEAST OF OUR ZONES. AT LEAST IN THE LOWER LEVELS...THIS
PLACEMENT WOULD RESULT IN OUR SOUTHERN ZONES RESIDING WITH A ZONE
OF GENERAL SUPPRESSION (DESCENDING AIR) ON THE COLD SIDE OF THE
FRONTS THERMAL CIRCULATION.
ALL THIS BEGIN SAID...WILL BE A VERY CLOSE CALL BETWEEN OUR FAR
SOUTHERN AND INTERIOR SOUTHERN ZONES
(HIGHLANDS/DESOTO/CHARLOTTE/LEE) AND THE NORTHERN EXTENT OF THE
POTENTIALLY ORGANIZED RAINFALL ZONE LATE TONIGHT INTO WEDNESDAY.
AS MENTIONED ABOVE...THE GFS/ECMWF HAVE BEEN CONSISTENT IN KEEPING
THE BEST LIFT AND MOST ORGANIZED SHOWER ACTIVITY GENERALLY OUT OF
OUR AREA FOR SEVERAL MODEL RUNS. THE NAM WHILE STILL FURTHER WEST
AND NORTHWEST WITH ITS LIFT AND RESULTING QPF FIELDS...HAS TRENDED
BACK FROM EARLIER SOLUTIONS. THIS GIVES SOME CONFIDENCE IN LESS
OVERALL SHOWER ACTIVITY AND RAINFALL AMOUNTS FROM HIGHLANDS COUNTY
TO LEE COUNTY...AND ESPECIALLY FURTHER NORTH AND NORTHWEST. WILL
HAVE TO KEEP SOME SHOWER CHANCES IN THE FORECAST BASED ON THE
INCREASINGLY FAVORABLE MOISTURE PROFILES...AND OVERALL PRESENCE OF
SYNOPTIC LIFT...BUT FEELING IS THAT A WASHOUT FOR THESE SOUTHERN
ZONES...WEDNESDAY WILL NOT BE. FURTHER NORTH TOWARD TAMPA BAY AND
NATURE COAST ZONES...JUST MENTIONING A FEW SPRINKLES ON WEDNESDAY.
MANY LOCATIONS ALONG AND NORTH OF THE I-4 CORRIDOR ARE LIKELY TO
NOT EVEN SEE MEASURABLE PRECIP.
GIVEN THE SYSTEM PASSING OVERHEAD...WILL SEE A MOSTLY CLOUDY DAY
FOR MOST ON WEDNESDAY...HOWEVER HIGH TEMPERATURES SHOULD BE UP
SEVERAL DEGREES FROM WHAT WE ARE SEEING THIS AFTERNOON.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST
FLORIDA FOR THE REMAINDER OF THE DAY. THE MAIN AVIATION CONCERN
WILL BE GUSTY NORTHEASTERLY WINDS WHICH WILL GUST IN EXCESS OF 20
KNOTS AT TIMES. THE WIND WILL BECOME LESS GUSTY WITH THE SETTING
OF THE SUN THIS EVENING...ESPECIALLY AWAY FROM THE IMMEDIATE
COAST.
&&
.MARINE...
...SMALL CRAFT ADVISORY IN EFFECT UNTIL 10 AM EST WEDNESDAY FOR
OFFSHORE WATERS FROM 20 TO 60 NM EXTENDING FROM BONITA BEACH TO
THE SUWANNEE RIVER...
...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 AM EST WEDNESDAY FOR
NEAR SHORE WATERS OUT TO 20 NM EXTENDING FROM BONITA BEACH TO THE
SUWANNEE RIVER...
...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 PM EST THIS AFTERNOON
FOR THE WATERS OF TAMPA BAY AND CHARLOTTE HARBOR...
STRONG HIGH PRESSURE WILL REMAIN CENTERED TO THE NORTH OF THE
REGION THROUGH WEDNESDAY. ELEVATED NORTHEASTERLY WINDS AND
ELEVATED SEAS WILL KEEP CONDITIONS AT OR NEAR ADVISORY LEVELS
THROUGH TONIGHT. THE GRADIENT IS EXPECTED TO RELAX MID TO LATE
WEEK ALLOWING WINDS AND SEAS TO SUBSIDE.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 69 54 72 57 / 0 10 10 10
FMY 72 58 74 59 / 10 10 30 20
GIF 67 54 71 55 / 10 10 20 20
SRQ 71 56 74 58 / 10 10 10 10
BKV 65 49 71 52 / 0 10 10 10
SPG 67 56 70 59 / 0 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR WATERS
FROM BONITA BEACH TO ENGLEWOOD FL OUT 20 TO 60 NM-
WATERS FROM ENGLEWOOD TO TARPON SPRINGS FL OUT 20 TO
60 NM-WATERS FROM TARPON SPRINGS TO SUWANNEE RIVER FL
OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR COASTAL
WATERS FROM BONITA BEACH TO ENGLEWOOD FL OUT 20 NM-
COASTAL WATERS FROM ENGLEWOOD TO TARPON SPRINGS FL
OUT 20 NM-COASTAL WATERS FROM TARPON SPRINGS TO
SUWANNEE RIVER FL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
CHARLOTTE HARBOR AND PINE ISLAND SOUND-TAMPA BAY
WATERS.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
DECISION SUPPORT SERVICES...MCKAUGHAN
AREA FORECAST DISCUSSION
NWS MIAMI FL
839 AM EST TUE JAN 5 2016
.UPDATE...
NE WIND SHIFT GRADUALLY SPREADING SOUTHEASTWARD ACROSS EAST COAST
AREAS THIS MRNG. ONCE WINDS SHIFT TO NE...TEMPERATURES WILL RISE
AROUND 10 DEGREES /FROM L60S TO L70S/...THEN LEVEL OFF THROUGH
MUCH OF THE DAY AS SHOWER COVERAGE GRADUALLY INCREASES. WILL BE
MONITORING RADAR TRENDS CLOSELY...FOR POSSIBLE NEED TO BOOST POPS
UP A BIT. FOR NOW...NO CHANGES WARRANTED.
&&
.PREV DISCUSSION... /ISSUED 653 AM EST TUE JAN 5 2016/
AVIATION...
VFR CONDITIONS ARE FORECAST TO PREVAIL THROUGH THE
FORECAST PERIOD EXCEPT FOR A SLIM CHC OF PERIODS OF MVFR CEILINGS
MAINLY ALONG THE SE FL COAST. BUT GIVEN CONFIDENCE ON THAT IS LOW IT
IS NOT CURRENTLY REFLECTED ON THE FORECAST AND WILL AMEND AS NEEDED
IF THIS BECOMES A CONCERN OR ADDRESS IN FUTURE UPDATES. SOMETHING
NOT PICKED UP BY SHORT TERM MOS GUIDANCE BUT PICKED UP BY HRRR AND A
COUPLE OF LOCAL MODEL RUNS IS A LAND BREEZE PARTICULARLY ALONG SE
COAST SITES FROM FLL NORTH THROUGH AROUND DAWN WHEN THE LOW LEVEL NE
FLOW KICKS IN. THIS IS IN LINE WITH CURRENT OBSERVATIONS SO
REFLECTED THE LAND BREEZE ON TAF FORECAST FOR SITES ALONG SE COAST
THE FIRST COUPLE OF HOURS OR SO OF THE FORECAST EARLY THIS MORNING.
BLUSTERY NE WINDS WILL DEVELOP BY MID TO LATE MORNING AT ALL SITES
AND CONTINUE INTO THE EVENING. SOME MOISTURE WILL STREAM NORTH FROM
THE SOUTH TODAY WARRANTING MENTION OF VCSH PARTICULARLY ALONG SE FL
SITES.
PREV DISCUSSION... /ISSUED 441 AM EST TUE JAN 5 2016/
DISCUSSION...
TODAY-WEDNESDAY...COOL START TO THE DAY ACROSS SOUTH FLORIDA WITH
TEMPERATURES RANGING FROM THE UPPER 40S ACROSS GLADES AND HENDRY, TO
THE LOW 50S ALONG THE GULF COAST AND UPPER 50S TO LOW 60S ALONG THE
EAST COAST METRO.
FT LAUDERDALE INTERNATIONAL HAS DROPPED TO 59F SO FAR THIS MORNING,
BREAKING THE OLD RECORD FOR LATEST BELOW 60F TEMP WHICH WAS
PREVIOUSLY 29 DEC 1986. MIAMI INTERNATIONAL CONTINUES TO HOVER
AROUND 60-61F, SO IT MAY ALSO DIP TO 59F OR BELOW THIS MORNING. THE
PREVIOUS RECORD FOR LATEST BELOW 60F TEMP AT MIAMI WAS 23 DEC 1994.
WEST PALM DIPPED TO 57F YESTERDAY MORNING ALSO SETTING A NEW RECORD
FOR LATEST BELOW 60F DAY.
RADAR ALREADY SHOWS LIGHT ECHOES OVER THE ATLANTIC AND EAST COAST,
THOUGH A LOT OF THIS IS LIKELY NOT YET REACHING THE GROUND. DEEPER
MOISTURE ASSOCIATED WITH THE FORMER BOUNDARY LIFTS BACK TO THE NORTH
AS ANOTHER SHORTWAVE SWINGS INTO THE STATE AND SPAWNS A WEAK AREA OF
LOW PRESSURE ALONG THE BOUNDARY OVER THE CENTRAL/NW BAHAMAS. RAIN
CHANCES WILL INCREASE ALONG THE EAST COAST AND FAR SOUTHERN
PENINSULA LATE THIS MORNING AS THIS MOISTURE COMES INTO THE REGION
ALONG WITH THE FORCING AHEAD OF THE TROUGH .
HOW MUCH RAIN WE SEE TONIGHT INTO WEDNESDAY WILL BE DEPENDENT ON
WHERE THE LOW ULTIMATELY FORMS AND WHERE BEST CONVERGENT BANDS END
UP. BUT IT LOOKS LIKE A WET PERIOD THROUGH WEDNESDAY AS THE STATE
ALSO WILL BE IN A FAVORABLE REGION BETWEEN THE DEPARTING AND
APPROACHING JETS. WILL HAVE TO MONITOR FOR A LOCALIZED POTENTIAL
FOCUS FOR HEAVY RAINFALL ALONG THE EAST COAST. COVERAGE AND
INTENSITY OF RAIN WILL DROP OFF INTO THE INTERIOR AND GULF COAST.
A FEW THUNDERSTORMS ARE POSSIBLE, MAINLY OVER THE GULF STREAM
STARTING LATE TONIGHT, WITH THE POSSIBILITY FOR A FEW CREEPING INTO
THE EAST COAST.
TEMPERATURES WILL REMAIN COOL TODAY IN THE LOW 70S WITH A FEW MID
70S POSSIBLE INTO WEDNESDAY ALONG THE EAST COAST AS EAST FLOW
COMPONENT INCREASES OF THE RELATIVELY WARM ATLANTIC WATERS. THIS
MORNING WILL BE THE COOLEST OF THE WEEK WITH TEMPERATURES
ONLY DROPPING INTO UPPER 50S-MID 60S THE NEXT TWO NIGHTS.
INCREASING ONSHORE WINDS ALONG THE ATLANTIC COAST WILL RESULT IN RIP
CURRENT FORMATION AT THE ATLANTIC BEACHES TUE-WED...AND A HIGH RISK
OF RIP CURRENTS IS FORECAST.
THURSDAY-WEEKEND...THE PROGRESSIVE AND UNSETTLED PATTERN CONTINUES
INTO THE UPCOMING WEEKEND AS THE JET STREAM REMAINS ACROSS THE
SOUTHERN TIER OF THE US.
UPPER LEVEL SHORTWAVE AND ASSOCIATED DEVELOPING SURFACE LOW OVER THE
BAHAMAS QUICKLY LIFT OUT TO THE NORTHEAST ON THURS, BRINGING IN A
BRIEF SHOT OF DRIER AIR AND LOW RAIN CHANCES.
THEN THE NEXT SHORTWAVE CROSSING THE SOUTHEASTERN US BRINGS A WEAK
SURFACE FRONT INTO THE STATE ALONG WITH A RETURN OF ADEQUATE, THOUGH
NOT VERY DEEP, MOISTURE. SCATTERED SHOWERS WILL BE IN THE FORECAST
ACROSS THE REGION FOR BOTH FRI AND SAT.
WHILE BOTH THE GFS AND ECMWF ARE IN REMARKABLY GOOD AGREEMENT FOR
THE LATE WEEKEND, THERE ARE SOME SLIGHT DIFFERENCES IN THE SURFACE
PATTERN. THE ECMWF IS A LITTLE STRONGER AND SLOWER WITH THE
REINFORCING FRONT THAN THE GFS AND DRIES THINGS OUT A LITTLE MORE
INTO MONDAY. OVERALL HOWEVER, BOTH SHOW SAT NIGHT INTO SUNDAY AS A
PERIOD OF ENHANCED PRECIP CHANCES THAT MAY LINGER INTO MONDAY FOR AT
LEAST THE SOUTHERN PARTS OF THE REGION.
TEMPS/HUMIDITY WILL MODERATE MID-LATE WEEK...INTO THE UPPER
70S/AROUND 80 FOR HIGHS AND 60S FOR LOWS. THIS WILL BE ABOVE NORMAL,
BUT NOWHERE NEAR THE WARMTH OF LATE DEC.
MARINE...
STRONG EAST-NORTHEAST WINDS 20-25KTS CONTINUE ACROSS BOTH GULF AND
ATLANTIC WATERS INTO WEDNESDAY. SEAS BUILD TO 4-6FT FOR THE OFFSHORE
GULF WATERS AND 9-11FT IN THE GULF STREAM LATER TODAY. HAVE EXTENDED
THE SMALL CRAFT ADVISORY FOR ALL THE WATERS, INCLUDING LAKE
OKEECHOBEE, THROUGH WEDNESDAY MORNING. HAZARDOUS CONDITIONS MAY
LINGER LONGER OVER THE ATLANTIC INTO LATE WEDNESDAY.
WINDS DIMINISH WED NIGHT AS AN AREA OF LOW PRESSURE DEVELOPS JUST TO
OUR SOUTHEAST AND DISRUPTS THE GRADIENT. WINDS BECOME LIGHT NW
BEHIND THE DEPARTING LOW INTO THURS AND THEN S-SW AHEAD OF ANOTHER
SYSTEM INTO FRI. SEAS WILL BE SLOWER TO SUBSIDE, AND HAZARDOUS SEAS
MAY LINGER IN THE GULF STREAM THROUGH FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 69 76 65 80 / 40 70 50 20
FORT LAUDERDALE 66 75 67 79 / 50 80 50 20
MIAMI 67 76 67 80 / 60 80 40 10
NAPLES 59 79 60 78 / 20 60 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR FLZ168-172-
173.
AM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR AMZ610-630-
650-651-670-671.
GM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR GMZ656-657-
676.
&&
$$
SHORT TERM...23/SK
LONG TERM....88/ALM
AREA FORECAST DISCUSSION
NWS MIAMI FL
653 AM EST TUE JAN 5 2016
.AVIATION...
VFR CONDITIONS ARE FORECAST TO PREVAIL THROUGH THE
FORECAST PERIOD EXCEPT FOR A SLIM CHC OF PERIODS OF MVFR CEILINGS
MAINLY ALONG THE SE FL COAST. BUT GIVEN CONFIDENCE ON THAT IS LOW IT
IS NOT CURRENTLY REFLECTED ON THE FORECAST AND WILL AMEND AS NEEDED
IF THIS BECOMES A CONCERN OR ADDRESS IN FUTURE UPDATES. SOMETHING
NOT PICKED UP BY SHORT TERM MOS GUIDANCE BUT PICKED UP BY HRRR AND A
COUPLE OF LOCAL MODEL RUNS IS A LAND BREEZE PARTICULARLY ALONG SE
COAST SITES FROM FLL NORTH THROUGH AROUND DAWN WHEN THE LOW LEVEL NE
FLOW KICKS IN. THIS IS IN LINE WITH CURRENT OBSERVATIONS SO
REFLECTED THE LAND BREEZE ON TAF FORECAST FOR SITES ALONG SE COAST
THE FIRST COUPLE OF HOURS OR SO OF THE FORECAST EARLY THIS MORNING.
BLUSTERY NE WINDS WILL DEVELOP BY MID TO LATE MORNING AT ALL SITES
AND CONTINUE INTO THE EVENING. SOME MOISTURE WILL STREAM NORTH FROM
THE SOUTH TODAY WARRANTING MENTION OF VCSH PARTICULARLY ALONG SE FL
SITES.
&&
.PREV DISCUSSION... /ISSUED 441 AM EST TUE JAN 5 2016/
DISCUSSION...
TODAY-WEDNESDAY...COOL START TO THE DAY ACROSS SOUTH FLORIDA WITH
TEMPERATURES RANGING FROM THE UPPER 40S ACROSS GLADES AND HENDRY, TO
THE LOW 50S ALONG THE GULF COAST AND UPPER 50S TO LOW 60S ALONG THE
EAST COAST METRO.
FT LAUDERDALE INTERNATIONAL HAS DROPPED TO 59F SO FAR THIS MORNING,
BREAKING THE OLD RECORD FOR LATEST BELOW 60F TEMP WHICH WAS
PREVIOUSLY 29 DEC 1986. MIAMI INTERNATIONAL CONTINUES TO HOVER
AROUND 60-61F, SO IT MAY ALSO DIP TO 59F OR BELOW THIS MORNING. THE
PREVIOUS RECORD FOR LATEST BELOW 60F TEMP AT MIAMI WAS 23 DEC 1994.
WEST PALM DIPPED TO 57F YESTERDAY MORNING ALSO SETTING A NEW RECORD
FOR LATEST BELOW 60F DAY.
RADAR ALREADY SHOWS LIGHT ECHOES OVER THE ATLANTIC AND EAST COAST,
THOUGH A LOT OF THIS IS LIKELY NOT YET REACHING THE GROUND. DEEPER
MOISTURE ASSOCIATED WITH THE FORMER BOUNDARY LIFTS BACK TO THE NORTH
AS ANOTHER SHORTWAVE SWINGS INTO THE STATE AND SPAWNS A WEAK AREA OF
LOW PRESSURE ALONG THE BOUNDARY OVER THE CENTRAL/NW BAHAMAS. RAIN
CHANCES WILL INCREASE ALONG THE EAST COAST AND FAR SOUTHERN
PENINSULA LATE THIS MORNING AS THIS MOISTURE COMES INTO THE REGION
ALONG WITH THE FORCING AHEAD OF THE TROUGH .
HOW MUCH RAIN WE SEE TONIGHT INTO WEDNESDAY WILL BE DEPENDENT ON
WHERE THE LOW ULTIMATELY FORMS AND WHERE BEST CONVERGENT BANDS END
UP. BUT IT LOOKS LIKE A WET PERIOD THROUGH WEDNESDAY AS THE STATE
ALSO WILL BE IN A FAVORABLE REGION BETWEEN THE DEPARTING AND
APPROACHING JETS. WILL HAVE TO MONITOR FOR A LOCALIZED POTENTIAL
FOCUS FOR HEAVY RAINFALL ALONG THE EAST COAST. COVERAGE AND
INTENSITY OF RAIN WILL DROP OFF INTO THE INTERIOR AND GULF COAST.
A FEW THUNDERSTORMS ARE POSSIBLE, MAINLY OVER THE GULF STREAM
STARTING LATE TONIGHT, WITH THE POSSIBILITY FOR A FEW CREEPING INTO
THE EAST COAST.
TEMPERATURES WILL REMAIN COOL TODAY IN THE LOW 70S WITH A FEW MID
70S POSSIBLE INTO WEDNESDAY ALONG THE EAST COAST AS EAST FLOW
COMPONENT INCREASES OF THE RELATIVELY WARM ATLANTIC WATERS. THIS
MORNING WILL BE THE COOLEST OF THE WEEK WITH TEMPERATURES
ONLY DROPPING INTO UPPER 50S-MID 60S THE NEXT TWO NIGHTS.
INCREASING ONSHORE WINDS ALONG THE ATLANTIC COAST WILL RESULT IN RIP
CURRENT FORMATION AT THE ATLANTIC BEACHES TUE-WED...AND A HIGH RISK
OF RIP CURRENTS IS FORECAST.
THURSDAY-WEEKEND...THE PROGRESSIVE AND UNSETTLED PATTERN CONTINUES
INTO THE UPCOMING WEEKEND AS THE JET STREAM REMAINS ACROSS THE
SOUTHERN TIER OF THE US.
UPPER LEVEL SHORTWAVE AND ASSOCIATED DEVELOPING SURFACE LOW OVER THE
BAHAMAS QUICKLY LIFT OUT TO THE NORTHEAST ON THURS, BRINGING IN A
BRIEF SHOT OF DRIER AIR AND LOW RAIN CHANCES.
THEN THE NEXT SHORTWAVE CROSSING THE SOUTHEASTERN US BRINGS A WEAK
SURFACE FRONT INTO THE STATE ALONG WITH A RETURN OF ADEQUATE, THOUGH
NOT VERY DEEP, MOISTURE. SCATTERED SHOWERS WILL BE IN THE FORECAST
ACROSS THE REGION FOR BOTH FRI AND SAT.
WHILE BOTH THE GFS AND ECMWF ARE IN REMARKABLY GOOD AGREEMENT FOR
THE LATE WEEKEND, THERE ARE SOME SLIGHT DIFFERENCES IN THE SURFACE
PATTERN. THE ECMWF IS A LITTLE STRONGER AND SLOWER WITH THE
REINFORCING FRONT THAN THE GFS AND DRIES THINGS OUT A LITTLE MORE
INTO MONDAY. OVERALL HOWEVER, BOTH SHOW SAT NIGHT INTO SUNDAY AS A
PERIOD OF ENHANCED PRECIP CHANCES THAT MAY LINGER INTO MONDAY FOR AT
LEAST THE SOUTHERN PARTS OF THE REGION.
TEMPS/HUMIDITY WILL MODERATE MID-LATE WEEK...INTO THE UPPER
70S/AROUND 80 FOR HIGHS AND 60S FOR LOWS. THIS WILL BE ABOVE NORMAL,
BUT NOWHERE NEAR THE WARMTH OF LATE DEC.
MARINE...
STRONG EAST-NORTHEAST WINDS 20-25KTS CONTINUE ACROSS BOTH GULF AND
ATLANTIC WATERS INTO WEDNESDAY. SEAS BUILD TO 4-6FT FOR THE OFFSHORE
GULF WATERS AND 9-11FT IN THE GULF STREAM LATER TODAY. HAVE EXTENDED
THE SMALL CRAFT ADVISORY FOR ALL THE WATERS, INCLUDING LAKE
OKEECHOBEE, THROUGH WEDNESDAY MORNING. HAZARDOUS CONDITIONS MAY
LINGER LONGER OVER THE ATLANTIC INTO LATE WEDNESDAY.
WINDS DIMINISH WED NIGHT AS AN AREA OF LOW PRESSURE DEVELOPS JUST TO
OUR SOUTHEAST AND DISRUPTS THE GRADIENT. WINDS BECOME LIGHT NW
BEHIND THE DEPARTING LOW INTO THURS AND THEN S-SW AHEAD OF ANOTHER
SYSTEM INTO FRI. SEAS WILL BE SLOWER TO SUBSIDE, AND HAZARDOUS SEAS
MAY LINGER IN THE GULF STREAM THROUGH FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 74 69 76 65 / 30 40 70 50
FORT LAUDERDALE 73 66 75 67 / 40 50 80 50
MIAMI 75 67 76 67 / 40 60 80 40
NAPLES 76 59 79 60 / 10 20 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH WEDNESDAY EVENING FOR FLZ168-172-
173.
AM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR AMZ610-630-
650-651-670-671.
GM...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR GMZ656-657-
676.
&&
$$
SHORT TERM...88/ALM
LONG TERM....88/ALM
AVIATION...52/PS
AREA FORECAST DISCUSSION
NWS MIAMI FL
1251 AM EST TUE JAN 5 2016
.AVIATION...
VFR CONDITIONS ARE FORECAST TO PREVAIL THROUGH THE FORECAST PERIOD
EXCEPT FOR A SLIM CHC OF PERIODS OF MVFR CEILINGS MAINLY ALONG THE
SE FL COAST. BUT GIVEN CONFIDENCE ON THAT IS LOW IT IS NOT
CURRENTLY REFLECTED ON THE FORECAST AND WILL AMEND AS NEEDED IF
THIS BECOMES A CONCERN OR ADDRESS IN FUTURE UPDATES. SOMETHING
NOT PICKED UP BY SHORT TERM MOS GUIDANCE BUT PICKED UP BY HRRR AND
A COUPLE OF LOCAL MODEL RUNS IS A LAND BREEZE PARTICULARLY ALONG
SE COAST SITES FROM FLL NORTH THROUGH AROUND DAWN WHEN THE LOW
LEVEL NE FLOW KICKS IN. THIS IS IN LINE WITH CURRENT OBSERVATIONS
SO REFLECTED THE LAND BREEZE ON TAF FORECAST FOR SITES FROM FLL
NORTH ACCORDINGLY THROUGH THE FIRST 6 HOURS OF THE FORECAST EARLY
THIS MORNING. AFTER DAWN BLUSTERY NE WINDS WILL DEVELOP THROUGH
THE DAY AT ALL SITES AND CONTINUE INTO THE EVENING. SOME MOISTURE
WILL STREAM NORTH FROM THE SOUTH TODAY WARRANTING MENTION OF VCSH
PARTICULARLY ALONG SE FL SITES.
&&
.PREV DISCUSSION... /ISSUED 833 PM EST MON JAN 4 2016/
UPDATE...
HIGH PRESSURE IS SLOWLY BUILDING IN BEHIND THE COLD FRONT THAT
MOVED THROUGH. THE WIND IS BECOMING LIGHT TONIGHT, WHICH MAY ALLOW
SOME OF THE TEMPERATURES IN THE INTERIOR AREAS TO BE SOMEWHAT
CHILLIER THAN WHAT HAS BEEN FORECAST. HOWEVER, AS THE HIGH BUILDS
TO THE NORTH, THE WIND IS EXPECTED TO INCREASE OUT OF THE
NORTHEAST TONIGHT. THIS WOULD HELP TO CURTAIL ANY RADIATIONAL
COOLING TONIGHT. OVERALL, THE FORECAST LOW TEMPERATURES SHOULD BE
FAIRLY CLOSE, WITH ISOLATED POCKETS OF SOMEWHAT LOWER TEMPS. HAVE
MADE NO ADJUSTMENTS AT THIS TIME.
OTHERWISE, THE WEATHER SHOULD BE MOSTLY QUIET THROUGH THE
OVERNIGHT HOURS. MADE SOME TWEAKS TO THE FORECAST TO ACCOUNT FOR
CURRENT CONDITIONS.
PREV DISCUSSION... /ISSUED 650 PM EST MON JAN 4 2016/
AVIATION...
VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD AS CONDITIONS
SHOULD BE QUIET UNTIL THE MORNING HOURS. THE WIND WILL BE
GENERALLY NORTHERLY FOR THE FIRST PART OF THE NIGHT AS HIGH
PRESSURE BUILDS IN TO THE NORTH. AS IT CONTINUES TO BUILD TONIGHT,
THE WIND WILL TURN MORE NORTHEASTERLY. THIS MAY BRING SOME SHOWERS
TO THE SOUTHEAST FLORIDA COASTAL AREAS BY TOMORROW MORNING. HAVE
ADDED VCSH TO THE SITES FOR THE DAY TOMORROW.
PREV DISCUSSION... /ISSUED 331 PM EST MON JAN 4 2016/
DISCUSSION...
A RARE COOL DAY THIS WINTER SEASON ACROSS SOUTH FLORIDA WITH TEMPS
MOST LOCALES REMAINING IN THE 60S...AND A FEW REACHING 70F ACROSS
THE EAST COAST METRO. VERY DRY AIR HAS ADVECTED DOWN THE PENINSULA
WITH DEWPOINTS INTO THE 30S AND 40S.
HIGH PRESSURE RIDGE NORTH OF THE AREA WILL PULL EAST AND ALLOW
WINDS TO QUICKLY TURN NORTHEASTERLY ACROSS SOUTH FLORIDA. THIS
WILL ALLOW FOR RAPID AIR MASS MODIFICATION WITH ATLANTIC MOISTURE
MOVING ONSHORE FROM EAST TO WEST LATE TONIGHT. WINDS WILL INCREASE
OUT OF THE NORTHEAST INTO THE 20-25 KT RANGE OVER THE ATLANTIC.
EXCELLENT SURFACE CONVERGENCE IS FORECAST TO RESULT IN SOME FAST
MOVING SHOWERS MOVING ONSHORE THE ATLANTIC COAST LATE TONIGHT THEN
HITTING AREAS FURTHER INLAND AS WELL ON TUESDAY.
THIS COULD BE THE FIST NIGHT THIS WINTER SEASON THAT THE EAST
COAST CLIMATE SITES FALL BELOW 60F, BUT NOT A CERTAINTY. MUCH WILL
DEPEND ON WHEN THE MODIFICATION OFF THE WARM GULF STREAM
COMMENCES. EITHER WAY, IT WILL FEEL COOL GIVEN HOW WARM WE HAVE
BEEN!
ANOTHER SHORTWAVE IS PROJECTED TO SPAWN LOW PRESSURE DEVELOP TO
OUR SOUTHEAST ON WEDNESDAY. HOW CLOSE THIS LOW DEVELOPS TO SE
FLORIDA WILL DETERMINE HOW MUCH RAIN WILL FALL...BUT MODEL
CONSENSUS IS ZONING IN ON A WET DAY AS MOISTURE GETS TOSSED AROUND
THE LOW AND FOCUSING ON SOUTHEAST FLORIDA WITH GOOD COASTAL
CONVERGENCE SETTING UP THERE. RAINFALL AMOUNTS ARE FORECAST TO BE
0.5-1.0" ACROSS SE FLORIDA...LESSENING INTERIOR/GULF COAST. WILL
HAVE TO MONITOR FOR A LOCALIZED POTENTIAL FOCUS FOR HEAVY
RAINFALL, PARTICULARLY ACROSS MIAMI-DADE.
THE SHORTWAVE MOVES OUT WITH DRYING CONDITIONS ON THURSDAY AHEAD
OF THE NEXT WEATHER MAKER FOR FRIDAY AND INTO THE
WEEKEND...ANOTHER GULF OF MEXICO SHORTWAVE TRAVERSING IN THE
ACTIVE SOUTHERN STREAM. THIS WILL BRING ANOTHER ROUGH OF SHOWERS
TO THE AREA. A FEW THUNDERSTORMS ARE POSSIBLE...EVEN WITH THE
WEDNESDAY SYSTEM, BUT PROBABILITIES TOO LOW TO INCLUDE IN THE
FORECAST EXCEPT OVER THE WARM GULF STREAM CURRENT WHERE
INSTABILITY WILL BE HIGHEST.
TEMPS/HUMIDITY WILL MODERATE MID-LATE WEEK...GOING BACK ABOVE
AVERAGE, BUT NOT AS MUCH AS RECENT WEEKS AND NOT AS HUMID EITHER
WITH 60-DEGREE DEWPOINTS RETURNING MID-LATE WEEK, NOT THE 70S.
INCREASING ONSHORE WINDS ALONG THE ATLANTIC COAST WILL RESULT IN
RIP CURRENT FORMATION AT THE ATLANTIC BEACHES TUE-WED...AND A HIGH
RISK OF RIP CURRENTS IS FORECAST THEN. /GREGORIA
MARINE...
NORTH WINDS WILL BECOME NORTHEAST WHILE INCREASE TO 20+ KNOTS
OVERNIGHT-TUE, LEADING TO RAPIDLY BUILDING SEAS, ESPECIALLY IN THE
GULF STREAM. A SMALL CRAFT ADVISORY CONTINUES IN EFFECT FOR ALL
LOCAL WATERS LATE TONIGHT-TUESDAY AND WILL NEED TO BE EXTENDED FOR
ESPECIALLY THE GULF STREAM BEYOND THIS TIME FRAME AS SEAS WILL
REMAIN ELEVATED THROUGH WED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 66 73 63 79 / 40 80 60 20
FORT LAUDERDALE 66 73 63 79 / 60 80 50 10
MIAMI 64 74 63 79 / 60 80 50 10
NAPLES 58 71 59 77 / 40 70 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ610-630-
650-651-670-671.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR GMZ656-657-
676.
&&
$$
SHORT TERM...52/PS
LONG TERM....88/ALM
AVIATION...52/PS
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1132 PM CST MON JAN 4 2016
.UPDATE...
ISSUED AT 835 PM CST MON JAN 4 2016
Quiet weather is expected across central and southeast Illinois
overnight as a ridge of high pressure crosses the area. The main
weather feature of note is a plume of clouds streaming southwest
across parts of central Illinois from Lake Michigan. The other low
clouds that had been across the area faded with the loss of
diurnal heating. 00Z ILX and forecast soundings indicate a strong
capping inversion around 850 mb, which is about the height of the
lake clouds. The flow beneath this inversion is progged to turn
easterly within the next hour or two, and southerly by morning.
These shifting winds should help to remove these clouds from the
local area within the next few hours. The mostly clear skies and
light winds expected over the area for the rest of the night will
provide good radiational cooling conditions. This will allow
temperatures to fall a few degrees cooler than the past couple
nights, but overnight lows are still expected to be above normal
for early January.
Going forecast is in good shape overall. Updated sky grids to
better depict the lake clouds and their expected disposition.
Otherwise, only made a few hourly grid tweaks for the latest and
expected overnight trends.
&&
.SHORT TERM...(Tonight)
ISSUED AT 240 PM CST MON JAN 4 2016
Earlier hole in the stratocumulus has filled in across much of the
forecast area this afternoon, due to diurnal development and
additional clouds advecting in from Lake Michigan. Latest NAM 925 mb
humidity guidance suggesting the mostly cloudy trend to persist
through about 9 pm before clearing out, while the HRRR scatters the
clouds out closer to 6 pm. With the diurnal nature of most of the
clouds, leaned more toward the faster solution. As ridge axis pushes
east across the state, winds will trend toward the southeast after
midnight. Most locations should fall into the lower 20s overnight,
but some teens likely across the I-74 corridor.
.LONG TERM...(Tuesday through Monday)
ISSUED AT 240 PM CST MON JAN 4 2016
Quiet weather pattern to hold across the area through Wednesday
evening as upper level heights build over the Midwest allowing
warmer air to filter back into the region. Temperatures will
moderate a few degrees on Tuesday with the stronger return flow
setting up Tuesday night into Wednesday. This should push temps
Wednesday afternoon to around 40 degrees with the above normal
temperatures holding into Saturday. The storm system that is slated
to push out of the Southern Plains later Wednesday will begin to
spread precip into our area by Thursday morning. If the precip does
arrive before dawn Thursday, most of the forecast models suggest
more of a rain or freezing rain threat across our far northern
areas. For now, will keep it rain or snow and refine any precip
type issues as we draw closer to the event. The better rain
chances will move in late Thursday, Thursday night into Friday as
the main area of forcing/lift from the southern stream wave
pushes across our area, with rainfall amounts still looking to be
around one half inch.
As the storm system shifts to our northeast on Saturday, colder air
poised to our northwest will shift southeast into the region with
steady or slowly falling temperatures for the afternoon. We will
still have low chance POPs going during the day with a transition
from rain, to a rain snow mixture as the colder air filters in
during the afternoon as gusty northwest winds build in. Much colder
air will shift into the area Saturday night and Sunday accompanied
by gusty northwest winds. Most models suggest 850 temps of around
-20C by late Saturday night or Sunday as the center of the cold
air mass slides southeast into our area. This should result in
morning lows of 10 to 20 degrees by Monday morning with daytime
highs struggling mostly through the 20s Monday afternoon with the
below normal temperatures expected to hold through most of next
week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1127 PM CST MON JAN 4 2016
Quiet/VFR conditions expected across the central Illinois
terminals through the 06Z TAF valid time. The low level flow has
veered sufficiently to blow the lake effect clouds over parts of
northern Illinois away from KBMI & KCMI. The remaining TAF sites
have been clear since the diurnal clouds faded earlier this
evening. Mostly clear skies should prevail for the duration of
the night and into Tuesday. Some high level CIGs should spread
into the area tomorrow ahead of a slowly approaching storm system,
but they should have no impact of flight operations. Variable
winds tonight with a high pressure ridge in the vicinity will
trend southerly and increase Tuesday as the high departs and low
pressure approaches.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...BAK
SHORT TERM...Geelhart
LONG TERM...Smith
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
814 PM CST WED JAN 6 2016
.UPDATE...
ISSUED AT 814 PM CST WED JAN 6 2016
LATEST WATER VAPOR IMAGERY SHOWS THE SHORTWAVE TROUGH AXIS MOVING
THROUGH CENTRAL IA...WITH AREA RADARS SHOWING ASSOCIATED
PRECIPITATION OVER CENTRAL INTO EAST CENTRAL IA. BASED ON SURFACE
OBSERVATIONS...THE PRECIPITATION IS MAINLY SNOW NW OF A DSM TO ALO
LINE...WITH LIGHT RAIN OR DRIZZLE TO THE SOUTHEAST WHERE SURFACE
TEMPERATURES WERE ABOVE 32. AN AREA OF ENHANCED REFLECTIVITY MOVING
ALONG THE I-80 AXIS WEST OF IOWA CITY INDICATES POSSIBLE SLEET
OCCURRING...SUPPORTED BY A SHALLOW SUB FREEZING LAYER ON KDVN
SOUNDING AROUND 500 TO 1500 FT AGL.
THE BULK OF THE PRECIPITATION APPEARS TO BE ON TRACK TO REMAIN
MAINLY NORTH OF I-80 AHEAD OF THE PASSING SHORTWAVE AND HAVE
UPDATED THE FORECAST TO SIMPLIFY TO A SNOW/SLEET MIX EARLY...THEN
LIGHT SNOW CHANGING TO LIGHT RAIN OVERNIGHT AS WARM ADVECTION SW
FLOW WARMS THE ENTIRE SUB 850 MB LAYER ABOVE FREEZING FROM SOUTH
TO NORTH OVERNIGHT TO NEAR THE HIGHWAY 20 CORRIDOR BY SUNRISE.
WITH UPSTREAM REPORTS SHOWING RATES AROUND .01 TO .02 PER HOUR AND
LIFT RAPIDLY SPREADING NORTHEAST...OVERNIGHT QPF SHOULD BE LESS
THAN A TENTH OF AN INCH WITH NEGLIGIBLE SNOWFALL. TO THE SOUTH
AND SE...LIFT IS WEAKER AND PRIMARILY DUE TO WARM/MOIST ADVECTION
ALOFT. ANY PRECIPITATION WILL HAVE TO OVERCOME DRY AIR IN THE LOW
LEVELS AND WILL ANTICIPATE PATCHY LIGHT LIGHT RAIN OR DRIZZLE
THROUGH THE REST OF THE NIGHT WITH NEAR STEADY TEMPERATURES AND
PAVEMENT TEMPERATURES HOLDING ABOVE FREEZING.
&&
.SYNOPSIS...
ISSUED AT 322 PM CST WED JAN 6 2016
HIGH PRESSURE WAS LOCATED ACROSS THE EASTERN SEABOARD AS A
DEVELOPING SURFACE LOW TOOK SHAPE ACROSS THE LEE OF THE ROCKIES. S
FLOW AT THE SFC A LONG WITH A SHORTWAVE ALOFT AIDED IN BRINGING
IN WARMER AND MORE MOIST AIR INTO THE REGION THIS AFTERNOON.
PRECIP ASSOCIATED WITH THIS INITIAL WAVE STRUGGLED TO REACH THE
GROUND AS DRY AIR WAS IN PLACE. THIS WILL CHANGE WITH THE
ADVECTION OF WARMER AIR...DEEPER MOISTURE AND ANOTHER WAVE AFFECTS
THE AREA THROUGH THE SHORT TERM.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 322 PM CST WED JAN 6 2016
MAIN FORECAST CONCERN IN THE SHORT TERM ARE THE THERMODYNAMICS AND
THE ASSOCIATED PRECIP TYPES WITH THEM. THERMAL PROFILES HOVER
AROUND FREEZING FROM THE SFC TO ALOFT...THIS IS LEADING TO A
TRICKY FORECAST ACROSS THE AREA. REGARDLESS...THE AREA IS EXPECTED
TO SEE MEASURABLE PRECIP THROUGH THE SHORT TERM....WITH MOST
LIQUID QPF VALUES LESS THAN 0.25 INCHES..EXCEPT FOR THE MO
COUNTIES THAT MAY SEE UNDER 0.5 INCHES.
FORECAST CHALLENGES ABOUND WITH DIFFICULT PTYPE FORECAST AND
POSSIBLE IMPACTS. GRIDDED AND SPECTRAL SYNOPTIC SCALE MODELS
SUGGEST THAT THE AREA WILL STAY COOLER LONGER...LEADING TO MORE OF
A MIX OF FZRA...RA..AND SN ACROSS THE AREA. WHEREAS THE RUC AND
OTHER CAMS ARE MORE INDICATIVE OF A QUICK CHANGE TO RAIN FROM
SNOW. THIS IS AT ODDS WITH THE TRADITIONAL WARM FRONT MODEL WITH
WARMING ALOFT THAT WOULD LEAD TO MIXED PRECIP. WOULD BE MORE
CONFIDENT IN A SOLUTION IF I SAW THE DEWPOINTS RISING AS WELL WITH
THE SFC TEMPS. CONCERNED THAT EVAPORATIVE COOLING COULD LEAD TO A
LARGER AREA OF FZRA...MORE LIKE THE SYNOPTIC SCALE MODELS.
AT THIS TIME WILL GO WITH A MIX MAINLY NORTH OF HWY 30 TONIGHT.
CLOSER TO 12Z AN AREA OF FZRA COULD FORM NEAR I80 BEFORE A
CHANGEOVER TO ALL RAIN. THERE COULD BE TRAVEL ISSUES EARLY IN THE
AM BEFORE THE FZRA SWITCHES OVER TO ALL RA IN THE MID AM. NORTH OF
HIGHWAY 30 COULD SEE SOME SLEET AND FZRA IN THE AM...THIS COULD
LEAD TO SOME TRAVEL ISSUES ACROSS THE NORTHERN ZONES. THE PLUS TO
THIS IS THAT WHATEVER FALLS OVERNIGHT AND TOMORROW AM WILL MELT
WITH THE RA IN THE AFTERNOON TOMORROW. OVERALL QPF AMOUNTS ARE
LOW...BUT WITH THE LIGHT RAIN RATES..THINK THAT A THIN GLAZE OF
ICE COULD COAT SOME ELEVATE OBJECTS AND POSSIBLY UNTREATED
ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES.
IT WILL BE IMPORTANT TO WATCH THE TEMPS AND DEWPOINTS TONIGHT.
THIS WILL HELP TO DETERMINE WHETHER OR NOT MORE FREEZING RAIN OR
RAIN WILL FALL.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 322 PM CST WED JAN 6 2016
THURSDAY NIGHT AND FRIDAY...PERIODS OF LIGHT RAIN ARE LIKELY OVER
EASTERN IOWA/WESTERN ILLINOIS/AND NORTHEAST MISSOURI. THE FIRST WAVE
SHOULD BE ONGOING FRIDAY EVENING...LASTING INTO THE FIRST HALF OF
THE NIGHT. TIME-HEIGHT SECTIONS SUGGEST THIS ROUND TO BE DRIVEN
MAINLY BY WARM AIR ADVECTION BETWEEN 850-700MB. SFC TEMPS SHOULD
HOLD STEADY OVERNIGHT THURSDAY IN THE SE SFC FLOW. EXPECTING LOWS IN
THE 33-34 F RANGE ACROSS THE NORTH ALONG HIGHWAY 20...MID 30S ALONG
I-80...AND MID TO UPPER 30S SOUTH OF HIGHWAY 34.
THEN AS THE WEAK 1005MB SFC LOW PULLS NORTHEASTWARD ACROSS E IOWA ON
FRIDAY WINDS ARE FORECAST TO VEER TO A MORE SOUTHERLY DIRECTION
THEREBY PULLING THE THERMAL RIDGE/THETA-E GRADIENT NORTHWARD INTO THE
DVN CWA. HAVE UPPER 40S IN THE FAR SOUTH...LOWER 40S NEAR THE QUAD
CITIES AND MID 30S FAR NORTH FOR HIGHS. THE 500MB VORTICITY MAX AND
ATTENDANT DCVA WILL CROSS THE REGION DURING THE DAY BRINGING A
SECONDARY WAVE OF LIGHT RAIN. A VERY LOW OVERCAST IS LIKELY AND
PERIODS OF DRIZZLE ARE POSSIBLE BASED ON THE SATURATED FORECAST
SOUNDINGS.
SATURDAY...A COMPACT SHORTWAVE IS FORECAST TO RIDE THE SW-TO-NE
ORIENTED 850MB BAROCLINIC ZONE THAT WILL BE DRAPED ACROSS THE
CENTRAL U.S. INTO THE WESTERN GREAT LAKES. MODELS VARY CONSIDERABLY
ON THE TRACK/STRENGTH OF THIS LOW BUT THERE IS THE POTENTIAL FOR
ACCUMULATING SNOW IN A PORTION OF THE DVN CWA.
AT THIS TIME...THE BETTER CHANCES FOR THE STEADIEST PRECIP ARE
ACROSS THE EASTERN CWA OR EAST OF THE MISSISSIPPI RIVER. PLENTY OF
TIME FOR THE MODELS TO ADJUST THE EVOLUTION OF THIS
SYSTEM...THEREFORE SHIFTS TO THE NW OR EVEN THE EAST REMAIN
POSSIBLE...CANNOT GET INTO MUCH OF THE DETAILS WITH THIS MUCH MODEL
UNCERTAINTY. WHAT IS MORE OF A SURE THING THIS FAR OUT IS GUSTY
NORTHWEST WINDS...POSSIBLY IN EXCESS OF 30 MPH. FOR AREAS THAT DO
RECEIVE SNOW...THE WINDS WOULD RESULT IN A HEIGHTENED TRAVEL IMPACT.
PLEASE STAY TUNED TO THE LATEST FORECASTS OVER THE NEXT FEW DAYS.
SUNDAY...ARCTIC AIR POISED TO DUMP INTO THE MIDWEST. CONSENSUS HIGHS
RANGE FROM NEAR 5 F BY INDEPENDENCE IOWA TO AROUND 12 F IN THE QUAD
CITIES...TO THE MID TEEN BY MACOMB ILLINOIS. 850MB TEMPS ARE
PROJECTED TO BOTTOM OUT NEAR -16 C TO -18 C AND 1000-500MB
THICKNESSES TO AN IMPRESSIVELY LOW 504 DAM ON THE ECMWF AND 510 DAM
ON THE GFS.
SUNDAY NIGHT...TEMPS ARE HIGHLY CONTINGENT ON HOW MUCH SNOW IS ON
THE GROUND OR IF THERE IS ANY. CURRENT MODEL CONSENSUS FORECAST HAS
SINGLE DIGITS LOWS ABOVE AND BELOW ZERO.
WIND CHILLS...LOOK TO BE COLDEST SUNDAY NIGHT AND MONDAY MORNING.
ADVISORY LEVEL VALUES NEAR -20 F ARE POSSIBLE...ESPECIALLY ALONG AND
NORTH OF HIGHWAY 30.
MONDAY AND TUESDAY...DAYTIME HIGHS SHOULD MODERATE A BIT INTO THE
TEENS MONDAY WITH TEENS/20S ON TUESDAY PER MODEL CONSENSUS.
OVERNIGHT LOWS SHOULD REMAIN ON THE COLD SIDE...IN THE SINGLE DIGITS
AND TEENS. CONFIDENCE FOR THE TEMP FORECAST ON TUESDAY IS LOW WITH
THE GFS AND ECMWF SHOWING DIFFERENT TEMP ADVECTION PATTERNS.
A CLIPPER TYPE SYSTEM MAY BRING SOME SNOW SHOWERS TO THE WESTERN
GREAT LAKES AREA ON TUESDAY...BUT ONLY HAVE SLIGHT CHANCES OVER THE
NE SECTION OF THE DVN CWA AS MODELS ARE NOT SHOWING MUCH IN THE WAY
OF MOISTURE RIGHT NOW. UTTECH
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 541 PM CST WED JAN 6 2016
AN UPPER LEVEL SYSTEM MOVING THROUGH CENTRAL IOWA WILL SPREAD A
WINTRY MIX ACROSS EASTERN IOWA THIS EVENING AND OVERNIGHT...FOLLOWED
BY A STRONGER SYSTEM LATE THURSDAY. TONIGHT...LIGHT SNOW WILL MOVE
INTO CID AND DBQ WITH FLIGHT CONDITIONS DROPPING EVENTUALLY TO IFR
LEVELS WITH PRECIPITATION LIKELY TO CHANGE TO LIGHT RAIN OR
DRIZZLE BY MORNING. MLI AND BRL WILL HAVE AN OVERALL LOWER
POTENTIAL FOR PRECIPITATION...WHICH IS MOST LIKELY TO BE IN THE
FORM OF RAIN OR DRIZZLE. ALL SITES WILL HAVE THE POTENTIAL FOR A
PERIOD OF LIGHT FREEZING RAIN OVERNIGHT BEFORE LOW LEVEL
TEMPERATURES RISE ABOVE FREEZING...BUT FORECAST CONFIDENCE IS TOO
LOW TO MENTION IN THE TERMINALS. THURSDAY...IFR TO LIFR CONDITIONS
ARE LIKELY DUE TO LOW CIGS...FOG AND VERY LIGHT RAIN OR DRIZZLE.
BRL WILL SEE THE ONSET OF THE NEXT ROUND OF LIGHT TO MODERATE RAIN
LATE AFTERN0ON WITH THE NEXT SYSTEM APPROACHING FROM THE SW.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...UTTECH
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
541 PM CST WED JAN 6 2016
...AVIATION UPDATE...
.SYNOPSIS...
ISSUED AT 322 PM CST WED JAN 6 2016
HIGH PRESSURE WAS LOCATED ACROSS THE EASTERN SEABOARD AS A
DEVELOPING SURFACE LOW TOOK SHAPE ACROSS THE LEE OF THE ROCKIES. S
FLOW AT THE SFC A LONG WITH A SHORTWAVE ALOFT AIDED IN BRINGING
IN WARMER AND MORE MOIST AIR INTO THE REGION THIS AFTERNOON.
PRECIP ASSOCIATED WITH THIS INITIAL WAVE STRUGGLED TO REACH THE
GROUND AS DRY AIR WAS IN PLACE. THIS WILL CHANGE WITH THE
ADVECTION OF WARMER AIR...DEEPER MOISTURE AND ANOTHER WAVE AFFECTS
THE AREA THROUGH THE SHORT TERM.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 322 PM CST WED JAN 6 2016
MAIN FORECAST CONCERN IN THE SHORT TERM ARE THE THERMODYNAMICS AND
THE ASSOCIATED PRECIP TYPES WITH THEM. THERMAL PROFILES HOVER
AROUND FREEZING FROM THE SFC TO ALOFT...THIS IS LEADING TO A
TRICKY FORECAST ACROSS THE AREA. REGARDLESS...THE AREA IS EXPECTED
TO SEE MEASURABLE PRECIP THROUGH THE SHORT TERM....WITH MOST
LIQUID QPF VALUES LESS THAN 0.25 INCHES..EXCEPT FOR THE MO
COUNTIES THAT MAY SEE UNDER 0.5 INCHES.
FORECAST CHALLENGES ABOUND WITH DIFFICULT PTYPE FORECAST AND
POSSIBLE IMPACTS. GRIDDED AND SPECTRAL SYNOPTIC SCALE MODELS
SUGGEST THAT THE AREA WILL STAY COOLER LONGER...LEADING TO MORE OF
A MIX OF FZRA...RA..AND SN ACROSS THE AREA. WHEREAS THE RUC AND
OTHER CAMS ARE MORE INDICATIVE OF A QUICK CHANGE TO RAIN FROM
SNOW. THIS IS AT ODDS WITH THE TRADITIONAL WARM FRONT MODEL WITH
WARMING ALOFT THAT WOULD LEAD TO MIXED PRECIP. WOULD BE MORE
CONFIDENT IN A SOLUTION IF I SAW THE DEWPOINTS RISING AS WELL WITH
THE SFC TEMPS. CONCERNED THAT EVAPORATIVE COOLING COULD LEAD TO A
LARGER AREA OF FZRA...MORE LIKE THE SYNOPTIC SCALE MODELS.
AT THIS TIME WILL GO WITH A MIX MAINLY NORTH OF HWY 30 TONIGHT.
CLOSER TO 12Z AN AREA OF FZRA COULD FORM NEAR I80 BEFORE A
CHANGEOVER TO ALL RAIN. THERE COULD BE TRAVEL ISSUES EARLY IN THE
AM BEFORE THE FZRA SWITCHES OVER TO ALL RA IN THE MID AM. NORTH OF
HIGHWAY 30 COULD SEE SOME SLEET AND FZRA IN THE AM...THIS COULD
LEAD TO SOME TRAVEL ISSUES ACROSS THE NORTHERN ZONES. THE PLUS TO
THIS IS THAT WHATEVER FALLS OVERNIGHT AND TOMORROW AM WILL MELT
WITH THE RA IN THE AFTERNOON TOMORROW. OVERALL QPF AMOUNTS ARE
LOW...BUT WITH THE LIGHT RAIN RATES..THINK THAT A THIN GLAZE OF
ICE COULD COAT SOME ELEVATE OBJECTS AND POSSIBLY UNTREATED
ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES.
IT WILL BE IMPORTANT TO WATCH THE TEMPS AND DEWPOINTS TONIGHT.
THIS WILL HELP TO DETERMINE WHETHER OR NOT MORE FREEZING RAIN OR
RAIN WILL FALL.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 322 PM CST WED JAN 6 2016
THURSDAY NIGHT AND FRIDAY...PERIODS OF LIGHT RAIN ARE LIKELY OVER
EASTERN IOWA/WESTERN ILLINOIS/AND NORTHEAST MISSOURI. THE FIRST WAVE
SHOULD BE ONGOING FRIDAY EVENING...LASTING INTO THE FIRST HALF OF
THE NIGHT. TIME-HEIGHT SECTIONS SUGGEST THIS ROUND TO BE DRIVEN
MAINLY BY WARM AIR ADVECTION BETWEEN 850-700MB. SFC TEMPS SHOULD
HOLD STEADY OVERNIGHT THURSDAY IN THE SE SFC FLOW. EXPECTING LOWS IN
THE 33-34 F RANGE ACROSS THE NORTH ALONG HIGHWAY 20...MID 30S ALONG
I-80...AND MID TO UPPER 30S SOUTH OF HIGHWAY 34.
THEN AS THE WEAK 1005MB SFC LOW PULLS NORTHEASTWARD ACROSS E IOWA ON
FRIDAY WINDS ARE FORECAST TO VEER TO A MORE SOUTHERLY DIRECTION
THEREBY PULLING THE THERMAL RIDGE/THETA-E GRADIENT NORTHWARD INTO THE
DVN CWA. HAVE UPPER 40S IN THE FAR SOUTH...LOWER 40S NEAR THE QUAD
CITIES AND MID 30S FAR NORTH FOR HIGHS. THE 500MB VORTICITY MAX AND
ATTENDANT DCVA WILL CROSS THE REGION DURING THE DAY BRINGING A
SECONDARY WAVE OF LIGHT RAIN. A VERY LOW OVERCAST IS LIKELY AND
PERIODS OF DRIZZLE ARE POSSIBLE BASED ON THE SATURATED FORECAST
SOUNDINGS.
SATURDAY...A COMPACT SHORTWAVE IS FORECAST TO RIDE THE SW-TO-NE
ORIENTED 850MB BAROCLINIC ZONE THAT WILL BE DRAPED ACROSS THE
CENTRAL U.S. INTO THE WESTERN GREAT LAKES. MODELS VARY CONSIDERABLY
ON THE TRACK/STRENGTH OF THIS LOW BUT THERE IS THE POTENTIAL FOR
ACCUMULATING SNOW IN A PORTION OF THE DVN CWA.
AT THIS TIME...THE BETTER CHANCES FOR THE STEADIEST PRECIP ARE
ACROSS THE EASTERN CWA OR EAST OF THE MISSISSIPPI RIVER. PLENTY OF
TIME FOR THE MODELS TO ADJUST THE EVOLUTION OF THIS
SYSTEM...THEREFORE SHIFTS TO THE NW OR EVEN THE EAST REMAIN
POSSIBLE...CANNOT GET INTO MUCH OF THE DETAILS WITH THIS MUCH MODEL
UNCERTAINTY. WHAT IS MORE OF A SURE THING THIS FAR OUT IS GUSTY
NORTHWEST WINDS...POSSIBLY IN EXCESS OF 30 MPH. FOR AREAS THAT DO
RECEIVE SNOW...THE WINDS WOULD RESULT IN A HEIGHTENED TRAVEL IMPACT.
PLEASE STAY TUNED TO THE LATEST FORECASTS OVER THE NEXT FEW DAYS.
SUNDAY...ARCTIC AIR POISED TO DUMP INTO THE MIDWEST. CONSENSUS HIGHS
RANGE FROM NEAR 5 F BY INDEPENDENCE IOWA TO AROUND 12 F IN THE QUAD
CITIES...TO THE MID TEEN BY MACOMB ILLINOIS. 850MB TEMPS ARE
PROJECTED TO BOTTOM OUT NEAR -16 C TO -18 C AND 1000-500MB
THICKNESSES TO AN IMPRESSIVELY LOW 504 DAM ON THE ECMWF AND 510 DAM
ON THE GFS.
SUNDAY NIGHT...TEMPS ARE HIGHLY CONTINGENT ON HOW MUCH SNOW IS ON
THE GROUND OR IF THERE IS ANY. CURRENT MODEL CONSENSUS FORECAST HAS
SINGLE DIGITS LOWS ABOVE AND BELOW ZERO.
WIND CHILLS...LOOK TO BE COLDEST SUNDAY NIGHT AND MONDAY MORNING.
ADVISORY LEVEL VALUES NEAR -20 F ARE POSSIBLE...ESPECIALLY ALONG AND
NORTH OF HIGHWAY 30.
MONDAY AND TUESDAY...DAYTIME HIGHS SHOULD MODERATE A BIT INTO THE
TEENS MONDAY WITH TEENS/20S ON TUESDAY PER MODEL CONSENSUS.
OVERNIGHT LOWS SHOULD REMAIN ON THE COLD SIDE...IN THE SINGLE DIGITS
AND TEENS. CONFIDENCE FOR THE TEMP FORECAST ON TUESDAY IS LOW WITH
THE GFS AND ECMWF SHOWING DIFFERENT TEMP ADVECTION PATTERNS.
A CLIPPER TYPE SYSTEM MAY BRING SOME SNOW SHOWERS TO THE WESTERN
GREAT LAKES AREA ON TUESDAY...BUT ONLY HAVE SLIGHT CHANCES OVER THE
NE SECTION OF THE DVN CWA AS MODELS ARE NOT SHOWING MUCH IN THE WAY
OF MOISTURE RIGHT NOW. UTTECH
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 541 PM CST WED JAN 6 2016
AN UPPER LEVEL SYSTEM MOVING THROUGH CENTRAL IOWA WILL SPREAD A
WINTRY MIX ACROSS EASTERN IOWA THIS EVENING AND OVERNIGHT...FOLLOWED
BY A STRONGER SYSTEM LATE THURSDAY. TONIGHT...LIGHT SNOW WILL MOVE
INTO CID AND DBQ WITH FLIGHT CONDITIONS DROPPING EVENTUALLY TO IFR
LEVELS WITH PRECIPITATION LIKELY TO CHANGE TO LIGHT RAIN OR
DRIZZLE BY MORNING. MLI AND BRL WILL HAVE AN OVERALL LOWER
POTENTIAL FOR PRECIPITATION...WHICH IS MOST LIKELY TO BE IN THE
FORM OF RAIN OR DRIZZLE. ALL SITES WILL HAVE THE POTENTIAL FOR A
PERIOD OF LIGHT FREEZING RAIN OVERNIGHT BEFORE LOW LEVEL
TEMPERATURES RISE ABOVE FREEZING...BUT FORECAST CONFIDENCE IS TOO
LOW TO MENTION IN THE TERMINALS. THURSDAY...IFR TO LIFR CONDITIONS
ARE LIKELY DUE TO LOW CIGS...FOG AND VERY LIGHT RAIN OR DRIZZLE.
BRL WILL SEE THE ONSET OF THE NEXT ROUND OF LIGHT TO MODERATE RAIN
LATE AFTERN0ON WITH THE NEXT SYSTEM APPROACHING FROM THE SW.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...UTTECH
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1219 AM MST TUE JAN 5 2016
.UPDATE...
ISSUED AT 1020 PM MST MON JAN 4 2016
UPDATE ISSUED TO ACCOUNT FOR LATEST CLOUD COVER TREND BASED OFF OF
CURRENT 11U-3.9U SATELLITE LOOP. REGION WILL CONTINUE TO SEE
INCREASED HIGH CLOUD COVER THRU THE OVERNIGHT AS SHIELD LIFTS OUT
OF SE COLORADO. OTHER CLOUD COVER ISSUE FOR TONIGHT WAS THE
WESTWARD PUSH/EXTENT OF THE LOW CLOUD DECK CURRENTLY EAST OF THE
HILL CITY AREA. LAST HOUR OR SO THIS DECK HAS BEEN TRUDGING WEST
AND DO THINK IT WILL CLIP PORTIONS OF RED WILLOW...DECATUR...
NORTON AND GRAHAM COUNTIES FOR A FEW HOURS. REST OF FORECAST IS ON
TRACK WITH ONLY SOME PATCHY FREEZING FOG IN PORTIONS OF THE
EASTERN CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 1245 PM MST MON JAN 4 2016
A RIDGE WILL REMAIN OVER THE PLAINS TONIGHT AND THEN SHIFT EAST
TUESDAY WITH SOUTHWEST FLOW ACROSS THE REGION. SURFACE HIGH PRESSURE
WILL REMAIN OVER THE PLAINS TONIGHT. HIGH PRESSURE WILL MOVE EAST
TUESDAY AS A SURFACE TROUGH MOVES INTO EASTERN COLORADO.
THE FORECAST WILL REMAIN DRY TONIGHT DUE TO SUBSIDENCE. A SHORTWAVE
WILL MOVE ACROSS THE FA TUESDAY BUT FORCING AND MOISTURE ARE BOTH
LACKING. POPS WILL BE NIL TONIGHT AND TUESDAY.
THE HRRR INDICATES THE POSSIBILITY OF SOME PATCHY FREEZING FOG EARLY
TUESDAY MORNING FOR A FEW HOURS NEAR NORTON AND GRAHAM COUNTIES.
CONFIDENCE IS RATHER LOW BUT CANNOT RULE IT OUT. PLAN TO INSERT SOME
PATCHY FREEZING FOG IN THAT AREA.
MIN TEMPERATURES TONIGHT SHOULD FALL BACK TO THE TEENS IN EASTERN
COLORADO WITH LOWER 20S ELSEWHERE. MAX TEMPERATURES TUESDAY SHOULD
REACH THE MID 40S.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 1214 AM MST TUE JAN 5 2016
LIGHT SNOW WILL CONTINUE THROUGH FRIDAY NIGHT AS THE SHORTWAVE
TROUGH MOVES THROUGH THE SOUTHERN PLAINS. ADDITIONAL ACCUMULATIONS
CURRENTLY LOOK TO BE AROUND AN INCH DURING THAT TIME. THE
REMAINDER OF THE LONG TERM PERIOD WILL HAVE A DEEP TROUGH NEAR THE
GREAT LAKES RESULTING IN NORTHERLY FLOW ALOFT OVER THE CENTRAL
PLAINS. THERE WILL BE A COUPLE OF WEAK DISTURBANCES IN THE FLOW
BUT MOISTURE WILL BE LACKING FOR ANY SIGNIFICANT SNOWFALL
CHANCES. TEMPERATURES WILL BE BELOW NORMAL...BUT MODEL TRENDS KEEP
THE CORE OF THE COLDEST AIR EAST OF THE LOCAL AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1020 PM MST MON JAN 4 2016
FOR KGLD...VFR CONDITIONS THRU FORECAST PERIOD WITH BKN200
TRENDING DOWN TO BKN090 BY 00Z WEDNESDAY. WINDS SSW 10-20KT WITH
GUSTS NEAR 30KTS BETWEEN 14Z TUES AND 00Z WEDNESDAY.
FOR KMCK...MAINLY VFR CONDITIONS THRU FORECAST PERIOD WITH
BKN100-200. LIFR POSSIBLE OVC004 FROM 07Z-09Z. WINDS SE AROUND
10KTS THRU 15Z...THEN SOUTH 10-20KTS BECOMING SE AROUND 10KTS
AGAIN BY 23Z TUESDAY.
BOTH SITES COULD SEE LOW LEVEL WIND SHEAR 06Z-15Z FROM THE SOUTH
AROUND 40 KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...FS
LONG TERM...024
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1021 PM MST MON JAN 4 2016
.UPDATE...
ISSUED AT 1020 PM MST MON JAN 4 2016
UPDATE ISSUED TO ACCOUNT FOR LATEST CLOUD COVER TREND BASED OFF OF
CURRENT 11U-3.9U SATELLITE LOOP. REGION WILL CONTINUE TO SEE
INCREASED HIGH CLOUD COVER THRU THE OVERNIGHT AS SHIELD LIFTS OUT
OF SE COLORADO. OTHER CLOUD COVER ISSUE FOR TONIGHT WAS THE
WESTWARD PUSH/EXTENT OF THE LOW CLOUD DECK CURRENTLY EAST OF THE
HILL CITY AREA. LAST HOUR OR SO THIS DECK HAS BEEN TRUDGING WEST
AND DO THINK IT WILL CLIP PORTIONS OF RED WILLOW...DECATUR...
NORTON AND GRAHAM COUNTIES FOR A FEW HOURS. REST OF FORECAST IS ON
TRACK WITH ONLY SOME PATCHY FREEZING FOG IN PORTIONS OF THE
EASTERN CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 1245 PM MST MON JAN 4 2016
A RIDGE WILL REMAIN OVER THE PLAINS TONIGHT AND THEN SHIFT EAST
TUESDAY WITH SOUTHWEST FLOW ACROSS THE REGION. SURFACE HIGH PRESSURE
WILL REMAIN OVER THE PLAINS TONIGHT. HIGH PRESSURE WILL MOVE EAST
TUESDAY AS A SURFACE TROUGH MOVES INTO EASTERN COLORADO.
THE FORECAST WILL REMAIN DRY TONIGHT DUE TO SUBSIDENCE. A SHORTWAVE
WILL MOVE ACROSS THE FA TUESDAY BUT FORCING AND MOISTURE ARE BOTH
LACKING. POPS WILL BE NIL TONIGHT AND TUESDAY.
THE HRRR INDICATES THE POSSIBILITY OF SOME PATCHY FREEZING FOG EARLY
TUESDAY MORNING FOR A FEW HOURS NEAR NORTON AND GRAHAM COUNTIES.
CONFIDENCE IS RATHER LOW BUT CANNOT RULE IT OUT. PLAN TO INSERT SOME
PATCHY FREEZING FOG IN THAT AREA.
MIN TEMPERATURES TONIGHT SHOULD FALL BACK TO THE TEENS IN EASTERN
COLORADO WITH LOWER 20S ELSEWHERE. MAX TEMPERATURES TUESDAY SHOULD
REACH THE MID 40S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 157 PM MST MON JAN 4 2016
THE UPPER SHORT WAVE TROUGH WILL CONTINUE TO LIFT OUT ACROSS THE
CENTRAL HIGH PLAINS REGION TUESDAY NIGHT AND WEDNESDAY MORNING
WITH THE SURFACE TROUGH PUSHING FAR ENOUGH EAST THAT PRECIPITATION
ASSOCIATED WITH THE OPEN WAVE WILL LIKELY REMAIN SOUTH AND EAST
OF THE FORECAST AREA. THERE WILL BE BRIEF SHORT WAVE RIDGING ALOFT
WEDNESDAY AND WEDNESDAY NIGHT WITH DRY CONDITIONS.
A SURFACE LOW REDEVELOPS OVER SOUTHEAST COLORADO AHEAD OF THE
NEXT TROUGH THAT MOVES ACROSS THE FORECAST AREA THURSDAY INTO
THURSDAY EVENING. THE SOUTHERLY FETCH OF GULF MOISTURE STREAMING
INTO THE PLAINS STATES TURNS IT`S FOCUS ON THE CENTRAL HIGH PLAINS
WITH A MORE SOUTHEASTERLY FLOW AS THE SURFACE LOW MOVES INTO THE
PANHANDLE REGION. MOISTURE INCREASES IN THE COLUMN THURSDAY...BUT
INITIALLY REMAINS DRYER BETWEEN 850-700MB...SO PRECIPITATION THAT
MOVES INTO THE AREA EARLY THURSDAY MORNING LOOKS LIKE IT MAY START
AS FREEZING DRIZZLE BEFORE SURFACE TEMPERATURES WARM DURING THE
DAY AND THE COLUMN APPROACHES SATURATION AROUND 18Z. THE SURFACE
LOW MOVES INTO SOUTHEAST KANSAS BY THURSDAY NIGHT WITH
TEMPERATURES FALLING AND QUICKLY CHANGING PRECIPITATION OVER TO
ALL SNOW. THE LOW MOVES INTO NORTHERN MISSOURI BY
FRIDAY...BRINGING THE LIGHT SNOW TO AN END FROM WEST TO EAST BY
FRIDAY NIGHT.
BEYOND FRIDAY...MODEL SOLUTIONS FALL OUT OF AGREEMENT. HOWEVER...BOTH
THE ECMWF AND GFS SHOW STRONG SURFACE COLD AIR ADVECTION AS THE
MAIN UPPER FLOW MOVES WELL SOUTH OVER NORTHERN MEXICO...SURFACE
HIGH PRESSURE MOVES INTO THE REGION SATURDAY AND CONTINUES INTO
THE SOUTHERN PLAINS ON SUNDAY. LOW TEMPERATURES IN THE SINGLE
DIGITS...AND POSSIBLY BELOW ZERO...MAY BE OBSERVED THROUGH THE
WEEKEND WITH HIGH TEMPERATURES ONLY REACHING INTO THE UPPER TEENS
TO MIDDLE 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1020 PM MST MON JAN 4 2016
FOR KGLD...VFR CONDITIONS THRU FORECAST PERIOD WITH BKN200
TRENDING DOWN TO BKN090 BY 00Z WEDNESDAY. WINDS SSW 10-20KT WITH
GUSTS NEAR 30KTS BETWEEN 14Z TUES AND 00Z WEDNESDAY.
FOR KMCK...MAINLY VFR CONDITIONS THRU FORECAST PERIOD WITH
BKN100-200. LIFR POSSIBLE OVC004 FROM 07Z-09Z. WINDS SE AROUND
10KTS THRU 15Z...THEN SOUTH 10-20KTS BECOMING SE AROUND 10KTS
AGAIN BY 23Z TUESDAY.
BOTH SITES COULD SEE LOW LEVEL WIND SHEAR 06Z-15Z FROM THE SOUTH
AROUND 40 KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...FS
LONG TERM...LOCKHART
AVIATION...JN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
337 PM EST TUE JAN 5 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 319 PM EST TUE JAN 5 2016
WV IMAGERY AND RAP ANALYSIS INDICATED MID/UPPER LEVEL RIDGING FROM
THE UPPER MS VALLEY INTO THE GREAT LAKES. AT THE SFC...A TIGHT PRES
GRADIENT AND STRONG SW FLOW PREVAILED OVER LAKE SUPERIOR AND UPPER
MI BTWN HIGH PRES OVER THE ERN LAKES AND FRONT/TROUGH FROM NW
ONTARIO INTO THE NRN PLAINS. SW GUSTS TODAY HAVE REACHED OVER 30 MPH
AT SOME LOCATIONS...ESPECIALLY EAST HALF AND ALONG DOWNSLOPING AREAS
ALONG LAKE SUPERIOR. MOISTENING WITH THE SW WIND ACROSS LAKE MI HAS
BROUGHT LOW CLOUDS INTO FAR ERN UPPER MI...S AND E FROM ISQ TO ERY.
THE PATCH OF LOW CLOUDS OVER NCNTRL WI AND SW UPPER MI FROM THIS
MORNING HAS DISSIPATED WITH DAYTIME MIXING.
TONIGHT...A SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WILL HELP
DRAG A WEAK SFC TROUGH/COLD FRONT INTO LAKE SUPERIOR. 850-800 MB
FGEN ASSOCIATED WITH THE FRONT ALONG WITH WEAK ISENTROPIC LIFT ON
295K SFC AND MOISTENING FROM WSW WINDS ACROSS LAKE SUPERIOR WILL
SUPPORT A SLIGHT CHANCE FOR LIGHT SNOW SHOWERS OR FLURRIES INTO THE
KEWEENAW. WITH THE MOIST LAYER ONLY TO AROUND -10C...SOME FZDZ MAY
ALSO BE POSSIBLE LATE TONIGHT INTO WED MORNING.
WEDNESDAY...MAY SEE A FEW LIGHT LES SHOWERS OVER THE NRN PORTIONS OF
THE KEWEENAW WED MORNING WITH SW WINDS AND 850MB TEMPS TO AROUND
-10C...BUT NOT SIGNIFICANT ACCUMULATIONS. A TROUGH WILL MOVE OVER
THE WRN FCST AREA AND OVER LAKE SUPERIOR IN THE AFTERNOON.
DEVELOPMENT OF 800-700 MB FGEN FORCING WILL PROMOTE AN ELONGATED
AREA OF LIGHT SNOW OVER MAINLY WRN/NWRN UPPER MI WED AFTERNOON.
MODEL CONSENSUS QPF SUGGESTS SNOW ACCUMS WOULD BE HALF AN INCH OR
LESS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 PM EST TUE JAN 5 2016
THE SECOND HALF OF THIS WORK WEEK WILL SEE MORE MODERATE
TEMPERATURES AND PERIODS OF LIGHT SNOW...BEFORE MUCH COLDER...ARCTIC
AIR ARRIVES FOR THE SECOND HALF OF THE WEEKEND. THAT ARCTIC AIR WILL
PRODUCE THE COLDEST TEMPERATURES OF THE WINTER THUS FAR AND PERIODS
OF LAKE EFFECT SNOW.
PRECIPITATION SHOULD MOVE INTO THE WESTERN U.P. WEDNESDAY
AFTERNOON/EVENING ALONG THE STALLED TROUGH OVER WESTERN LAKE
SUPERIOR AND ASSOCIATED WITH INCREASING MOISTURE AND MID LEVEL
Q-VECTOR CONVERGENCE WITH THE SHORTWAVE LIFTING NORTHEAST OUT OF
THE CENTRAL PLAINS. WILL LIKELY SEE TWO WAVES...WITH THE FIRST AN
ELONGATED WSW TO ENE AREA OF SNOW STRETCHING ACROSS THE WESTERN
HALF OF THE U.P. AND ASSOCIATED WITH 900-750MB FGEN FORCING. THE
SECOND PUSH ARRIVES LATE WEDNESDAY NIGHT INTO THURSDAY AS THE
SHORTWAVE AND 850-700MB WARM AIR ADVECTION PUSHES THROUGH. EXPECT
ALL OF THIS PRECIP TO FALL AS SNOW LATE WEDNESDAY AFTERNOON INTO
THURSDAY...BUT WITH MUCH OF THE FORCING BELOW THE DGZ...THINK
SNOW-TO-LIQUID RATIOS WILL BE RIGHT AROUND 10-1 FOR MUCH OF THE
EVENT. COMPARED TO YESTERDAY...ONLY SOME MINOR ADJUSTMENTS HAVE
BEEN MADE TO THE FORECAST AND IT STILL LOOKS LIKE 1-2 INCHES OF
SNOW OVER A 24HR PERIOD...WITH A FEW SLIGHTLY HIGHER AMOUNTS NEAR
IRONWOOD. WITH THE DEEP MOISTURE CUTTING OUT BEHIND THE SHORTWAVE
(ASSOCIATED WITH THE WEAK MID-LEVEL RIDGING)...THERE IS THE
POTENTIAL FOR SOME FREEZING DRIZZLE THURSDAY AFTERNOON AND
EVENING...BUT MODELS VARY ON THE AMOUNT OF LOW LEVEL MOISTURE (NAM
SHOWING ABUNDANT MOISTURE WHILE THE GFS AND OUR REGIONAL WRF
MAINTAIN A 2-3KFT STRATUS DECK. WILL LEAVE OUT FREEZING DRIZZLE FOR
NOW...BUT MAY NEED TO ADD IF THE MODELS TREND TOWARDS THE NAM.
THE NEXT WAVE OF LIGHT PRECIPITATION WILL MOVE NORTHEAST INTO THE
AREA FRIDAY INTO SATURDAY AS A WEAK LOW LIFTS FROM MISSOURI AT 12Z
FRIDAY TO JAMES BAY BY 12Z SUNDAY. AT THIS POINT...IT LOOKS LIKE THE
BEST FORCING WILL BE OVER THE EASTERN U.P. WITH THE BEST PUSH OF
SNOW MOVING THROUGH DURING THE DAY ON FRIDAY (GENERALLY 1-3 INCHES
OVER 18-24HRS). STILL LOOKS LIKE THERE WILL BE ENOUGH LOW LEVEL
WARMING TO RAISE WETBULB0 HEIGHTS TO LEAD TO A LITTLE BIT OF RAIN
MIXING IN WITH THE SNOW ALONG THE BAY OF GREEN BAY SHORELINE IN
MENOMINEE COUNTY AND WILL CONTINUE TO INCLUDE A SLIGHT CHANCE TO
CHANCE OF RAIN THERE.
WHILE THE LOW IS FAIRLY WEAK AND BRINGS SOME LIGHT SNOW FRIDAY
INTO FRIDAY NIGHT...A STRONG WAVE FROM THE ARCTIC WILL BE DIVING
SOUTH ACROSS THE CANADIAN PRAIRIES AND BE MOVING TOWARDS THE GREAT
LAKES REGION FOR THE SECOND HALF OF THE WEEKEND AND FOR EARLY NEXT
WEEK. THAT WILL LEAD TO A SIGNIFICANT TRANSITION IN TEMPERATURES...
FROM THE LOWER 30S FOR THE LATER HALF OF THIS WEEK TO HIGHS IN THE
SINGLE DIGITS TO LOWER TEENS ABOVE ZERO ON MONDAY. THAT COLD AIR
(850MB TEMPS FALLING TO -20C ON SUNDAY EVENING AND -23C ON MONDAY)
WILL KICK THE LAKE EFFECT MACHINE BACK INTO GEAR FOR THE AREA...BUT
THE COLD TEMPERATURES WILL KEEP THE CLOUD GENERALLY ABOVE THE DGZ
LEADING TO SMALLER FLAKES. WHILE THAT WILL LIKELY KEEP SNOWFALL
AMOUNTS IN CHECK...THE HIGH INVERSION HEIGHTS (RISING TO 12KFT ON
SUNDAY WITH LK INDUCED CAPES NEARING 1000 J/KG) WOULD SUPPORT
STRONG BANDS THAT WOULD BE VERY EFFECTIVE AT REDUCING VISIBILITIES.
WHILE THERE IS STILL SOME UNCERTAINTY ON THE WIND FIELD (DUE TO
DIFFERENCES IN THE EVOLUTION OF A SECONDARY WAVE AND POSSIBLE LOW
MOVING UP THE EASTERN HALF OF THE CONUS)...WOULD EXPECT A GRADUAL
TRANSITION FROM NORTHWEST TO WEST-SOUTHWEST SUNDAY THROUGH TUESDAY.
FOLLOWED THAT IDEA FOR THE POPS AND WILL CONTINUE TO SHOW DEFINITE
POPS IN THE MOST FAVORED AREAS NEAR LAKE SUPERIOR. STILL WAY TO
EARLY FOR GETTING AN IDEA ON SNOW AMOUNTS...BUT WOULD EXPECT AT
LEAST SOME ADVISORY SNOWFALL AMOUNTS FOR THE NW TO WNW WIND AREAS.
WILL ADD A MENTION OF THE COLD AIR AND SNOW WITH REDUCED
VISIBILITIES TO THE HWO FOR AREAS NEAR LAKE SUPERIOR FOR THE SUNDAY
INTO MONDAY PERIOD.
DID LOWER HIGHS A FEW DEGREES OVER THE INTERIOR WEST FOR
MONDAY...AS RAW MODEL DATA CONTINUES TO INDICATE HIGHS STRUGGLING
TO REACH ZERO ALONG THE WISCONSIN BORDER. LOOKING BACK AT PAST DAYS
WITH HIGHS AT OR BELOW ZERO AT OUR OFFICE AND ALSO THE STAMBAUGH
COOP, THERE IS A CONSISTENT IDEA OF 850MB TEMPS BEING AROUND OR
BELOW -23C (WHICH IS SIMILAR TO THE 12Z GFS AND THE 12Z ECMWF IS
COLDER). WHILE THE 00Z ECMWF ENSEMBLE MEAN IS AROUND -17C...FELT
COMFORTABLE IN LOWERING HIGHS OUT WEST AND AWAY FROM LAKE SUPERIOR
CLOSER TO ZERO. IF THE COLD SIGNAL REMAINS...WILL LIKELY NEED TO
LOWER HIGHS A LITTLE FURTHER ON MONDAY. AT OUR OFFICE...THINK THE
MODERATION FROM LAKE SUPERIOR WILL HELP TO KEEP HIGHS IN THE MID TO
UPPER SINGLE DIGITS ABOVE ZERO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1241 PM EST TUE JAN 5 2016
EXPECT GUSTY SW WINDS FROM 20-25 KT THROUGH THE AFTERNOON AT TAF
SITES. EXPECT VFR CONDITIONS TO PREVAIL THROUGH TODAY...WITH
DOWNSLOPE NATURE OF THE SW FLOW HELPING TO MAINTAIN LOWER RH.
HOWEVER...GUIDANCE SUGGESTS LOW CLOUDS WILL ARRIVE TONIGHT...WITH
FCST MVFR CIGS TO ARRIVE OVERNIGHT. THE BEST CHANCE FOR IFR CIGS WILL
BE AT IWD OVERNIGHT. LIGHT IS ALSO POSSIBLE AT KCMX BY WED MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 319 PM EST TUE JAN 5 2016
A TIGHT PRES GRADIENT BTWN A DEPARTING HIGH PRES RIDGE AND LOW PRES
TROUGH FROM HUDSON BAY TO THE NRN PLAINS MAY STILL SUPPORT SW GALES
INTO ERN LAKE SUPERIOR THIS EVENING. OTHERWISE EXPECT GALES TO
DIMINISH TONIGHT AS GRADIENT GRADUALLY WEAKENS. WINDS WILL DIMINISH
FURTHER WED/THU TO MOSTLY UNDER 20KT AS A LOW PRES TROUGH SETTLES
OVER THE UPPER GREAT LAKES. WINDS WILL INCREASE AGAIN THIS WEEKEND
AS LOW PRES LIFTS NE INTO THE GREAT LAKES REGION AND CAA ENSUES IN
NW FLOW.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265>267.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ243-244-263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
319 PM EST TUE JAN 5 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 319 PM EST TUE JAN 5 2016
WV IMAGERY AND RAP ANALYSIS INDICATED MID/UPPER LEVEL RIDGING FROM
THE UPPER MS VALLEY INTO THE GREAT LAKES. AT THE SFC...A TIGHT PRES
GRADIENT AND STRONG SW FLOW PREVAILED OVER LAKE SUPERIOR AND UPPER
MI BTWN HIGH PRES OVER THE ERN LAKES AND FRONT/TROUGH FROM NW
ONTARIO INTO THE NRN PLAINS. SW GUSTS TODAY HAVE REACHED OVER 30 MPH
AT SOME LOCATIONS...ESPECIALLY EAST HALF AND ALONG DOWNSLOPING AREAS
ALONG LAKE SUPERIOR. MOISTENING WITH THE SW WIND ACROSS LAKE MI HAS
BROUGHT LOW CLOUDS INTO FAR ERN UPPER MI...S AND E FROM ISQ TO ERY.
THE PATCH OF LOW CLOUDS OVER NCNTRL WI AND SW UPPER MI FROM THIS
MORNING HAS DISSIPATED WITH DAYTIME MIXING.
TONIGHT...A SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WILL HELP
DRAG A WEAK SFC TROUGH/COLD FRONT INTO LAKE SUPERIOR. 850-800 MB
FGEN ASSOCIATED WITH THE FRONT ALONG WITH WEAK ISENTROPIC LIFT ON
295K SFC AND MOISTENING FROM WSW WINDS ACROSS LAKE SUPERIOR WILL
SUPPORT A SLIGHT CHANCE FOR LIGHT SNOW SHOWERS OR FLURRIES INTO THE
KEWEENAW. WITH THE MOIST LAYER ONLY TO AROUND -10C...SOME FZDZ MAY
ALSO BE POSSIBLE LATE TONIGHT INTO WED MORNING.
WEDNESDAY...MAY SEE A FEW LIGHT LES SHOWERS OVER THE NRN PORTIONS OF
THE KEWEENAW WED MORNING WITH SW WINDS AND 850MB TEMPS TO AROUND
-10C...BUT NOT SIGNIFICANT ACCUMULATIONS. A TROUGH WILL MOVE OVER
THE WRN FCST AREA AND OVER LAKE SUPERIOR IN THE AFTERNOON.
DEVELOPMENT OF 800-700 MB FGEN FORCING WILL PROMOTE AN ELONGATED
AREA OF LIGHT SNOW OVER MAINLY WRN/NWRN UPPER MI WED AFTERNOON.
MODEL CONSENSUS QPF SUGGESTS SNOW ACCUMS WOULD BE HALF AN INCH OR
LESS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM EST TUE JAN 5 2016
MAY SEE A FEW LIGHT LES SHOWERS OVER THE NRN PORTIONS OF THE
KEWEENAW WED MORNING WITH SW WINDS AND 850MB TEMPS AROUND -9C...BUT
NOT SIGNIFICANT ACCUMULATIONS. A TROUGH AND SFC FRONT STALL OUT OVER
THE AREA ON WED AND STAY INTO THU NIGHT. DEVELOPMENT OF LOW-MID
LEVEL FGEN FORCING WILL PROMOTE AN ELONGATED AREA OF LIGHT SNOW OVER
MAINLY WRN/NWRN UPPER MI WED AFTERNOON AND EVENING. A SHORTWAVE AND
WAA WILL THEN LEAD TO WIDESPREAD LIGHT SNOW WED NIGHT INTO
THU...ENDING TIME UNCERTAIN WITH DIFFERING MODEL SOLUTIONS. EXPECT
SNOW TO LIQUID RATIOS AROUND 10 TO 1 GIVEN MOST OF THE WEAK LIFT IS
BELOW THE DGZ...WHICH WHEN COMBINED WITH TOTAL QPF AMOUNTS OF 0.10-
0.25 INCHES (LOWEST SE AND GREATEST OVER THE W AND NW) EXPECT
GENERALLY 1 TO JUST OVER 2 INCHES OF SNOW IN THE 24-30 HOUR PERIOD.
ANOTHER PERIOD OF LIGHT AND INSIGNIFICANT SNOW IS EXPECTED FRI AND
SAT AS A WEAK LOW MOVES FROM MO AT 12Z FRI TO QUEBEC OR JAMES BAY
(DEPENDING ON MODEL SOLUTION) BY 00Z SUN. STILL LOOKS LIKE BEST
FORCING/PRECIP WILL BE OVER THE ERN AND MAYBE SRN UPPER MI IN THE
FRI AFTERNOON/FRI NIGHT TIME FRAME. STILL SEEING MODEL DIFFERENCES
ON TIMING. COULD SEE SOME RAIN MIX IN FRI AFTERNOON OVER SERN UPPER
MI AS WET BULB ZERO HEIGHTS RISE WITH HIGHS IN THE MID 30S. OVERALL
ONLY EXPECTING A VERY MINOR 1-3 INCHES OF SNOW OVER 36 HOURS.
MAIN STORY IN THE LONG TERM IS THAT MODEL PERSIST IN SHOWING AN
ACTIVE WAVE MOVING INTO THE AREA SAT NIGHT AND DEEPENING INTO A
CLOSED UPPER LOW OVER OR NEAR THE CWA LATE SUN AND SUN NIGHT. 850MB
TEMPS AS LOW AS -25C ARE CO-LOCATED WITH THE LOW. MODELS ALSO
CONTINUE TO SHOW ANOTHER WAVE MOVING IN MID NEXT WEEK...WHICH WILL
REINFORCE THE COLD AIR. TEMPS WILL GO FROM HIGHS IN THE UPPER 20S TO
MID 30S AND LOWS IN THE 20S LATE IN THE WEEK TO HIGHS IN THE SINGLE
DIGITS TO TEENS ABOVE ZERO AND LOWS IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO EARLY NEXT WEEK. NW-W WIND SNOWBELTS WILL CERTAINLY SEE
PERSISTENT LES SAT NIGHT THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...BUT NOT EXPECTING WARNING AMOUNTS AT THIS TIME DUE TO SMALL
FLAKE SIZE GIVEN VERY COLD TEMPS (CLOUD LAYER COLDER THAN THE
PREFERRED DGZ). THAT COLD AIR WILL ALSO MARK THE FIRST TIME OUR
OFFICE WILL FALL BELOW ZERO SINCE MARCH 28...2015. THROUGH JANUARY
3...THAT MAKES A 281 DAY STREAK AND IS CURRENTLY TIED FOR THE 16TH
LONGEST STREAK. IF THE CURRENT FORECAST HOLDS...WE WILL MAKE IT TO
AROUND 288 OR 289 DAYS...WHICH WOULD BE RIGHT AROUND THE 9TH LONGEST
STREAK OF TEMPERATURES AT OR ABOVE ZERO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1241 PM EST TUE JAN 5 2016
EXPECT GUSTY SW WINDS FROM 20-25 KT THROUGH THE AFTERNOON AT TAF
SITES. EXPECT VFR CONDITIONS TO PREVAIL THROUGH TODAY...WITH
DOWNSLOPE NATURE OF THE SW FLOW HELPING TO MAINTAIN LOWER RH.
HOWEVER...GUIDANCE SUGGESTS LOW CLOUDS WILL ARRIVE TONIGHT...WITH
FCST MVFR CIGS TO ARRIVE OVERNIGHT. THE BEST CHANCE FOR IFR CIGS WILL
BE AT IWD OVERNIGHT. LIGHT IS ALSO POSSIBLE AT KCMX BY WED MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 319 PM EST TUE JAN 5 2016
A TIGHT PRES GRADIENT BTWN A DEPARTING HIGH PRES RIDGE AND LOW PRES
TROUGH FROM HUDSON BAY TO THE NRN PLAINS MAY STILL SUPPORT SW GALES
INTO ERN LAKE SUPERIOR THIS EVENING. OTHERWISE EXPECT GALES TO
DIMINISH TONIGHT AS GRADIENT GRADUALLY WEAKENS. WINDS WILL DIMINISH
FURTHER WED/THU TO MOSTLY UNDER 20KT AS A LOW PRES TROUGH SETTLES
OVER THE UPPER GREAT LAKES. WINDS WILL INCREASE AGAIN THIS WEEKEND
AS LOW PRES LIFTS NE INTO THE GREAT LAKES REGION AND CAA ENSUES IN
NW FLOW.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265>267.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ243-244-263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1244 PM EST TUE JAN 5 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EST TUE JAN 5 2016
WV IMAGERY AND RAP ANALYSIS INDICATED MID/UPPER LEVEL RIDGING FROM
THE UPPER MS VALLEY INTO THE WRN GREAT LAKES. AT THE SFC...A TIGHT
PRES GRADIENT AND STRONG SW FLOW PREVAILED OVER LAKE SUPERIOR AND
UPPER MI BTWN HIGH PRES OVER THE ERN LAKES AND FRONT/TROUGH FROM NW
ONTARIO INTO THE NRN PLAINS. MOISTENING WITH THE SW WIND ACROSS LAKE
MI HAS BROUGH LOW CLOUDS INTO FAR ERN UPPER MI...S AND E FROM ISQ TO
ERY. A BAND OF CLOUDS HAS ALSO DEVELOPED NE FROM THE BAY OF GREEN
BAY. UPSTREAM A LARGER AREA OF LOW CLOUDS FROM ERN MN AND FAR WRN WI
WAS GRADUALLY LIFTING TO THE NNE TO HYR-EAU.
TODAY...HIGH RES MODELS 925 MB RH FCSTS...IN LINE WITH CURRENT
TRENDS...SUGGEST THAT THE CLOUDS OVER NW WI WILL GRADUALLY SPREAD
INTO THE SW PORTION OF UPPER MI TODAY BUT THIN OUT OVER CNTRL
AREAS...ESPECIALLY WHERE DOWNSLOPE SW WINDS PREVAIL. THE CLOUDS OVER
THE ERN CWA ARE EXPECTED TO PUSH FARTHER TO THE EAST. EVEN WITH
LIMITED DAYTIME MIXING AS TEMPS CLIMB INTO THE UPPER 20S TO AROUND
30...WINDS WILL BECOME GUSTY TO AROUND 25-30 MPH.
TONIGHT...A SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WILL HELP
DRAG A WEAK COLD FRONT INTO LAKE SUPERIOR. 850-700 MB FGEN
ASSOCIATED WITH THE FRONT ALONG WITH WEAK ISENTROPIC LIFT ALONG WITH
MOISTENING FROM WSW WINDS ACROSS LAKE SUPERIOR WILL SUPPORT A SLIGHT
CHANCE FOR LIGHT SNOW SHOWERS OR FLURRIES INTO THE KEWEENAW. WITH
THE MOIST LAYER ONLY TO AROUND -10C...SOME FZDZ MAY ALSO BE
POSSIBLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM EST TUE JAN 5 2016
MAY SEE A FEW LIGHT LES SHOWERS OVER THE NRN PORTIONS OF THE
KEWEENAW WED MORNING WITH SW WINDS AND 850MB TEMPS AROUND -9C...BUT
NOT SIGNIFICANT ACCUMULATIONS. A TROUGH AND SFC FRONT STALL OUT OVER
THE AREA ON WED AND STAY INTO THU NIGHT. DEVELOPMENT OF LOW-MID
LEVEL FGEN FORCING WILL PROMOTE AN ELONGATED AREA OF LIGHT SNOW OVER
MAINLY WRN/NWRN UPPER MI WED AFTERNOON AND EVENING. A SHORTWAVE AND
WAA WILL THEN LEAD TO WIDESPREAD LIGHT SNOW WED NIGHT INTO
THU...ENDING TIME UNCERTAIN WITH DIFFERING MODEL SOLUTIONS. EXPECT
SNOW TO LIQUID RATIOS AROUND 10 TO 1 GIVEN MOST OF THE WEAK LIFT IS
BELOW THE DGZ...WHICH WHEN COMBINED WITH TOTAL QPF AMOUNTS OF 0.10-
0.25 INCHES (LOWEST SE AND GREATEST OVER THE W AND NW) EXPECT
GENERALLY 1 TO JUST OVER 2 INCHES OF SNOW IN THE 24-30 HOUR PERIOD.
ANOTHER PERIOD OF LIGHT AND INSIGNIFICANT SNOW IS EXPECTED FRI AND
SAT AS A WEAK LOW MOVES FROM MO AT 12Z FRI TO QUEBEC OR JAMES BAY
(DEPENDING ON MODEL SOLUTION) BY 00Z SUN. STILL LOOKS LIKE BEST
FORCING/PRECIP WILL BE OVER THE ERN AND MAYBE SRN UPPER MI IN THE
FRI AFTERNOON/FRI NIGHT TIME FRAME. STILL SEEING MODEL DIFFERENCES
ON TIMING. COULD SEE SOME RAIN MIX IN FRI AFTERNOON OVER SERN UPPER
MI AS WET BULB ZERO HEIGHTS RISE WITH HIGHS IN THE MID 30S. OVERALL
ONLY EXPECTING A VERY MINOR 1-3 INCHES OF SNOW OVER 36 HOURS.
MAIN STORY IN THE LONG TERM IS THAT MODEL PERSIST IN SHOWING AN
ACTIVE WAVE MOVING INTO THE AREA SAT NIGHT AND DEEPENING INTO A
CLOSED UPPER LOW OVER OR NEAR THE CWA LATE SUN AND SUN NIGHT. 850MB
TEMPS AS LOW AS -25C ARE CO-LOCATED WITH THE LOW. MODELS ALSO
CONTINUE TO SHOW ANOTHER WAVE MOVING IN MID NEXT WEEK...WHICH WILL
REINFORCE THE COLD AIR. TEMPS WILL GO FROM HIGHS IN THE UPPER 20S TO
MID 30S AND LOWS IN THE 20S LATE IN THE WEEK TO HIGHS IN THE SINGLE
DIGITS TO TEENS ABOVE ZERO AND LOWS IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO EARLY NEXT WEEK. NW-W WIND SNOWBELTS WILL CERTAINLY SEE
PERSISTENT LES SAT NIGHT THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...BUT NOT EXPECTING WARNING AMOUNTS AT THIS TIME DUE TO SMALL
FLAKE SIZE GIVEN VERY COLD TEMPS (CLOUD LAYER COLDER THAN THE
PREFERRED DGZ). THAT COLD AIR WILL ALSO MARK THE FIRST TIME OUR
OFFICE WILL FALL BELOW ZERO SINCE MARCH 28...2015. THROUGH JANUARY
3...THAT MAKES A 281 DAY STREAK AND IS CURRENTLY TIED FOR THE 16TH
LONGEST STREAK. IF THE CURRENT FORECAST HOLDS...WE WILL MAKE IT TO
AROUND 288 OR 289 DAYS...WHICH WOULD BE RIGHT AROUND THE 9TH LONGEST
STREAK OF TEMPERATURES AT OR ABOVE ZERO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1241 PM EST TUE JAN 5 2016
EXPECT GUSTY SW WINDS FROM 20-25 KT THROUGH THE AFTERNOON AT TAF
SITES. EXPECT VFR CONDITIONS TO PREVAIL THROUGH TODAY...WITH
DOWNSLOPE NATURE OF THE SW FLOW HELPING TO MAINTAIN LOWER RH.
HOWEVER...GUIDANCE SUGGESTS LOW CLOUDS WILL ARRIVE TONIGHT...WITH
FCST MVFR CIGS TO ARRIVE OVERNIGHT. THE BEST CHANCE FOR IFR CIGS WILL
BE AT IWD OVERNIGHT. LIGHT IS ALSO POSSIBLE AT KCMX BY WED MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 525 AM EST TUE JAN 5 2016
A TIGHT PRES GRADIENT BTWN A DEPARTING HIGH PRES RIDGE AND LOW PRES
TROUGH FROM HUDSON BAY TO THE NRN PLAINS WILL SUPPORT SW GALES
ACROSS LAKE SUPERIOR TODAY. THE GALES WILL BEGIN TO DIMINISH
TONIGHT. WINDS WILL DIMINISH FURTHER WED/THU TO MOSTLY UNDER 20KT AS
A LOW PRES TROUGH SETTLES OVER THE UPPER GREAT LAKES. WINDS WILL
INCREASE AGAIN FRI/SAT AS LOW PRES LIFTS NE INTO THE GREAT LAKES
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265>267.
GALE WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR LSZ162.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ243-244-263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
654 AM EST TUE JAN 5 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EST TUE JAN 5 2016
WV IMAGERY AND RAP ANALYSIS INDICATED MID/UPPER LEVEL RIDGING FROM
THE UPPER MS VALLEY INTO THE WRN GREAT LAKES. AT THE SFC...A TIGHT
PRES GRADIENT AND STRONG SW FLOW PREVAILED OVER LAKE SUPERIOR AND
UPPER MI BTWN HIGH PRES OVER THE ERN LAKES AND FRONT/TROUGH FROM NW
ONTARIO INTO THE NRN PLAINS. MOISTENING WITH THE SW WIND ACROSS LAKE
MI HAS BROUGH LOW CLOUDS INTO FAR ERN UPPER MI...S AND E FROM ISQ TO
ERY. A BAND OF CLOUDS HAS ALSO DEVELOPED NE FROM THE BAY OF GREEN
BAY. UPSTREAM A LARGER AREA OF LOW CLOUDS FROM ERN MN AND FAR WRN WI
WAS GRADUALLY LIFTING TO THE NNE TO HYR-EAU.
TODAY...HIGH RES MODELS 925 MB RH FCSTS...IN LINE WITH CURRENT
TRENDS...SUGGEST THAT THE CLOUDS OVER NW WI WILL GRADUALLY SPREAD
INTO THE SW PORTION OF UPPER MI TODAY BUT THIN OUT OVER CNTRL
AREAS...ESPECIALLY WHERE DOWNSLOPE SW WINDS PREVAIL. THE CLOUDS OVER
THE ERN CWA ARE EXPECTED TO PUSH FARTHER TO THE EAST. EVEN WITH
LIMITED DAYTIME MIXING AS TEMPS CLIMB INTO THE UPPER 20S TO AROUND
30...WINDS WILL BECOME GUSTY TO AROUND 25-30 MPH.
TONIGHT...A SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WILL HELP
DRAG A WEAK COLD FRONT INTO LAKE SUPERIOR. 850-700 MB FGEN
ASSOCIATED WITH THE FRONT ALONG WITH WEAK ISENTROPIC LIFT ALONG WITH
MOISTENING FROM WSW WINDS ACROSS LAKE SUPERIOR WILL SUPPORT A SLIGHT
CHANCE FOR LIGHT SNOW SHOWERS OR FLURRIES INTO THE KEWEENAW. WITH
THE MOIST LAYER ONLY TO AROUND -10C...SOME FZDZ MAY ALSO BE
POSSIBLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM EST TUE JAN 5 2016
MAY SEE A FEW LIGHT LES SHOWERS OVER THE NRN PORTIONS OF THE
KEWEENAW WED MORNING WITH SW WINDS AND 850MB TEMPS AROUND -9C...BUT
NOT SIGNIFICANT ACCUMULATIONS. A TROUGH AND SFC FRONT STALL OUT OVER
THE AREA ON WED AND STAY INTO THU NIGHT. DEVELOPMENT OF LOW-MID
LEVEL FGEN FORCING WILL PROMOTE AN ELONGATED AREA OF LIGHT SNOW OVER
MAINLY WRN/NWRN UPPER MI WED AFTERNOON AND EVENING. A SHORTWAVE AND
WAA WILL THEN LEAD TO WIDESPREAD LIGHT SNOW WED NIGHT INTO
THU...ENDING TIME UNCERTAIN WITH DIFFERING MODEL SOLUTIONS. EXPECT
SNOW TO LIQUID RATIOS AROUND 10 TO 1 GIVEN MOST OF THE WEAK LIFT IS
BELOW THE DGZ...WHICH WHEN COMBINED WITH TOTAL QPF AMOUNTS OF 0.10-
0.25 INCHES (LOWEST SE AND GREATEST OVER THE W AND NW) EXPECT
GENERALLY 1 TO JUST OVER 2 INCHES OF SNOW IN THE 24-30 HOUR PERIOD.
ANOTHER PERIOD OF LIGHT AND INSIGNIFICANT SNOW IS EXPECTED FRI AND
SAT AS A WEAK LOW MOVES FROM MO AT 12Z FRI TO QUEBEC OR JAMES BAY
(DEPENDING ON MODEL SOLUTION) BY 00Z SUN. STILL LOOKS LIKE BEST
FORCING/PRECIP WILL BE OVER THE ERN AND MAYBE SRN UPPER MI IN THE
FRI AFTERNOON/FRI NIGHT TIME FRAME. STILL SEEING MODEL DIFFERENCES
ON TIMING. COULD SEE SOME RAIN MIX IN FRI AFTERNOON OVER SERN UPPER
MI AS WET BULB ZERO HEIGHTS RISE WITH HIGHS IN THE MID 30S. OVERALL
ONLY EXPECTING A VERY MINOR 1-3 INCHES OF SNOW OVER 36 HOURS.
MAIN STORY IN THE LONG TERM IS THAT MODEL PERSIST IN SHOWING AN
ACTIVE WAVE MOVING INTO THE AREA SAT NIGHT AND DEEPENING INTO A
CLOSED UPPER LOW OVER OR NEAR THE CWA LATE SUN AND SUN NIGHT. 850MB
TEMPS AS LOW AS -25C ARE CO-LOCATED WITH THE LOW. MODELS ALSO
CONTINUE TO SHOW ANOTHER WAVE MOVING IN MID NEXT WEEK...WHICH WILL
REINFORCE THE COLD AIR. TEMPS WILL GO FROM HIGHS IN THE UPPER 20S TO
MID 30S AND LOWS IN THE 20S LATE IN THE WEEK TO HIGHS IN THE SINGLE
DIGITS TO TEENS ABOVE ZERO AND LOWS IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO EARLY NEXT WEEK. NW-W WIND SNOWBELTS WILL CERTAINLY SEE
PERSISTENT LES SAT NIGHT THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...BUT NOT EXPECTING WARNING AMOUNTS AT THIS TIME DUE TO SMALL
FLAKE SIZE GIVEN VERY COLD TEMPS (CLOUD LAYER COLDER THAN THE
PREFERRED DGZ). THAT COLD AIR WILL ALSO MARK THE FIRST TIME OUR
OFFICE WILL FALL BELOW ZERO SINCE MARCH 28...2015. THROUGH JANUARY
3...THAT MAKES A 281 DAY STREAK AND IS CURRENTLY TIED FOR THE 16TH
LONGEST STREAK. IF THE CURRENT FORECAST HOLDS...WE WILL MAKE IT TO
AROUND 288 OR 289 DAYS...WHICH WOULD BE RIGHT AROUND THE 9TH LONGEST
STREAK OF TEMPERATURES AT OR ABOVE ZERO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 654 AM EST TUE JAN 5 2016
STRONG SW WINDS ABOVE A NOCTURNAL INVERSION WILL RESULT IN LLWS
UNTIL LATE MORNING. WITH SOME DAYTIME HEATING...EXPECT GUSTY SW
WINDS BY LATE MORNING THROUGH THE AFTERNOON. HOW QUICKLY THIS SW
FLOW TAPS MOISTER AIR TO THE SW OF UPPER MI IS ANOTHER FCST CONCERN.
RIGHT NOW...EXPECT VFR CONDITIONS TO PREVAIL THROUGH TODAY...WITH
DOWNSLOPE NATURE OF THE SW FLOW HELPING TO MAINTAIN LOWER RH. BUT
EVEN THE DRIER GUIDANCE HINTS LOW CLOUDS WILL ARRIVE TONIGHT...SO
FCST MVFR CIGS TO ARRIVE THIS EVENING. THE BEST CHANCE FOR IFR CIGS
WILL BE AT IWD OVERNIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 525 AM EST TUE JAN 5 2016
A TIGHT PRES GRADIENT BTWN A DEPARTING HIGH PRES RIDGE AND LOW PRES
TROUGH FROM HUDSON BAY TO THE NRN PLAINS WILL SUPPORT SW GALES
ACROSS LAKE SUPERIOR TODAY. THE GALES WILL BEGIN TO DIMINISH
TONIGHT. WINDS WILL DIMINISH FURTHER WED/THU TO MOSTLY UNDER 20KT AS
A LOW PRES TROUGH SETTLES OVER THE UPPER GREAT LAKES. WINDS WILL
INCREASE AGAIN FRI/SAT AS LOW PRES LIFTS NE INTO THE GREAT LAKES
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ243-244-265>267.
GALE WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR LSZ162.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
526 AM EST TUE JAN 5 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EST TUE JAN 5 2016
WV IMAGERY AND RAP ANALYSIS INDICATED MID/UPPER LEVEL RIDGING FROM
THE UPPER MS VALLEY INTO THE WRN GREAT LAKES. AT THE SFC...A TIGHT
PRES GRADIENT AND STRONG SW FLOW PREVAILED OVER LAKE SUPERIOR AND
UPPER MI BTWN HIGH PRES OVER THE ERN LAKES AND FRONT/TROUGH FROM NW
ONTARIO INTO THE NRN PLAINS. MOISTENING WITH THE SW WIND ACROSS LAKE
MI HAS BROUGH LOW CLOUDS INTO FAR ERN UPPER MI...S AND E FROM ISQ TO
ERY. A BAND OF CLOUDS HAS ALSO DEVELOPED NE FROM THE BAY OF GREEN
BAY. UPSTREAM A LARGER AREA OF LOW CLOUDS FROM ERN MN AND FAR WRN WI
WAS GRADUALLY LIFTING TO THE NNE TO HYR-EAU.
TODAY...HIGH RES MODELS 925 MB RH FCSTS...IN LINE WITH CURRENT
TRENDS...SUGGEST THAT THE CLOUDS OVER NW WI WILL GRADUALLY SPREAD
INTO THE SW PORTION OF UPPER MI TODAY BUT THIN OUT OVER CNTRL
AREAS...ESPECIALLY WHERE DOWNSLOPE SW WINDS PREVAIL. THE CLOUDS OVER
THE ERN CWA ARE EXPECTED TO PUSH FARTHER TO THE EAST. EVEN WITH
LIMITED DAYTIME MIXING AS TEMPS CLIMB INTO THE UPPER 20S TO AROUND
30...WINDS WILL BECOME GUSTY TO AROUND 25-30 MPH.
TONIGHT...A SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WILL HELP
DRAG A WEAK COLD FRONT INTO LAKE SUPERIOR. 850-700 MB FGEN
ASSOCIATED WITH THE FRONT ALONG WITH WEAK ISENTROPIC LIFT ALONG WITH
MOISTENING FROM WSW WINDS ACROSS LAKE SUPERIOR WILL SUPPORT A SLIGHT
CHANCE FOR LIGHT SNOW SHOWERS OR FLURRIES INTO THE KEWEENAW. WITH
THE MOIST LAYER ONLY TO AROUND -10C...SOME FZDZ MAY ALSO BE
POSSIBLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM EST TUE JAN 5 2016
MAY SEE A FEW LIGHT LES SHOWERS OVER THE NRN PORTIONS OF THE
KEWEENAW WED MORNING WITH SW WINDS AND 850MB TEMPS AROUND -9C...BUT
NOT SIGNIFICANT ACCUMULATIONS. A TROUGH AND SFC FRONT STALL OUT OVER
THE AREA ON WED AND STAY INTO THU NIGHT. DEVELOPMENT OF LOW-MID
LEVEL FGEN FORCING WILL PROMOTE AN ELONGATED AREA OF LIGHT SNOW OVER
MAINLY WRN/NWRN UPPER MI WED AFTERNOON AND EVENING. A SHORTWAVE AND
WAA WILL THEN LEAD TO WIDESPREAD LIGHT SNOW WED NIGHT INTO
THU...ENDING TIME UNCERTAIN WITH DIFFERING MODEL SOLUTIONS. EXPECT
SNOW TO LIQUID RATIOS AROUND 10 TO 1 GIVEN MOST OF THE WEAK LIFT IS
BELOW THE DGZ...WHICH WHEN COMBINED WITH TOTAL QPF AMOUNTS OF 0.10-
0.25 INCHES (LOWEST SE AND GREATEST OVER THE W AND NW) EXPECT
GENERALLY 1 TO JUST OVER 2 INCHES OF SNOW IN THE 24-30 HOUR PERIOD.
ANOTHER PERIOD OF LIGHT AND INSIGNIFICANT SNOW IS EXPECTED FRI AND
SAT AS A WEAK LOW MOVES FROM MO AT 12Z FRI TO QUEBEC OR JAMES BAY
(DEPENDING ON MODEL SOLUTION) BY 00Z SUN. STILL LOOKS LIKE BEST
FORCING/PRECIP WILL BE OVER THE ERN AND MAYBE SRN UPPER MI IN THE
FRI AFTERNOON/FRI NIGHT TIME FRAME. STILL SEEING MODEL DIFFERENCES
ON TIMING. COULD SEE SOME RAIN MIX IN FRI AFTERNOON OVER SERN UPPER
MI AS WET BULB ZERO HEIGHTS RISE WITH HIGHS IN THE MID 30S. OVERALL
ONLY EXPECTING A VERY MINOR 1-3 INCHES OF SNOW OVER 36 HOURS.
MAIN STORY IN THE LONG TERM IS THAT MODEL PERSIST IN SHOWING AN
ACTIVE WAVE MOVING INTO THE AREA SAT NIGHT AND DEEPENING INTO A
CLOSED UPPER LOW OVER OR NEAR THE CWA LATE SUN AND SUN NIGHT. 850MB
TEMPS AS LOW AS -25C ARE CO-LOCATED WITH THE LOW. MODELS ALSO
CONTINUE TO SHOW ANOTHER WAVE MOVING IN MID NEXT WEEK...WHICH WILL
REINFORCE THE COLD AIR. TEMPS WILL GO FROM HIGHS IN THE UPPER 20S TO
MID 30S AND LOWS IN THE 20S LATE IN THE WEEK TO HIGHS IN THE SINGLE
DIGITS TO TEENS ABOVE ZERO AND LOWS IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO EARLY NEXT WEEK. NW-W WIND SNOWBELTS WILL CERTAINLY SEE
PERSISTENT LES SAT NIGHT THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...BUT NOT EXPECTING WARNING AMOUNTS AT THIS TIME DUE TO SMALL
FLAKE SIZE GIVEN VERY COLD TEMPS (CLOUD LAYER COLDER THAN THE
PREFERRED DGZ). THAT COLD AIR WILL ALSO MARK THE FIRST TIME OUR
OFFICE WILL FALL BELOW ZERO SINCE MARCH 28...2015. THROUGH JANUARY
3...THAT MAKES A 281 DAY STREAK AND IS CURRENTLY TIED FOR THE 16TH
LONGEST STREAK. IF THE CURRENT FORECAST HOLDS...WE WILL MAKE IT TO
AROUND 288 OR 289 DAYS...WHICH WOULD BE RIGHT AROUND THE 9TH LONGEST
STREAK OF TEMPERATURES AT OR ABOVE ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1236 AM EST TUE JAN 5 2016
INCRSG SW WIND TNGT ABOVE LLVL INVRN ENHANCED BY NOCTURNAL COOLING
WL RESULT IN LLWS AT ALL 3 SITES THIS MRNG. WITH SOME DAYTIME
HEATING...EXPECT GUSTY SW WINDS BY LATE MRNG THRU THE AFTN. HOW
QUICKLY THIS SW FLOW TAPS MOISTER AIR WELL TO THE SW OF UPR MI IS
ANOTHER FCST CONCERN. RIGHT NOW...EXPECT VFR CONDITIONS TO PREVAIL
THRU TODAY...WITH DOWNSLOPE NATURE OF THE SW FLOW HELPING TO
MAINTAIN LOWER RH. BUT EVEN THE DRIER GUIDANCE HINTS LO CLDS WL
ARRIVE TNGT...SO FCST MVFR CIGS TO ARRIVE THIS EVNG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 525 AM EST TUE JAN 5 2016
A TIGHT PRES GRADIENT BTWN A DEPARTING HIGH PRES RIDGE AND LOW PRES
TROUGH FROM HUDSON BAY TO THE NRN PLAINS WILL SUPPORT SW GALES
ACROSS LAKE SUPERIOR TODAY. THE GALES WILL BEGIN TO DIMINISH
TONIGHT. WINDS WILL DIMINISH FURTHER WED/THU TO MOSTLY UNDER 20KT AS
A LOW PRES TROUGH SETTLES OVER THE UPPER GREAT LAKES. WINDS WILL
INCREASE AGAIN FRI/SAT AS LOW PRES LIFTS NE INTO THE GREAT LAKES
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265>267.
GALE WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR LSZ162.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ263-264.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ243-244.
LAKE MICHIGAN...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 AM EST TUE JAN 5 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EST TUE JAN 5 2016
WV IMAGERY AND RAP ANALYSIS INDICATED MID/UPPER LEVEL RIDGING FROM
THE UPPER MS VALLEY INTO THE WRN GREAT LAKES. AT THE SFC...A TIGHT
PRES GRADIENT AND STRONG SW FLOW PREVAILED OVER LAKE SUPERIOR AND
UPPER MI BTWN HIGH PRES OVER THE ERN LAKES AND FRONT/TROUGH FROM NW
ONTARIO INTO THE NRN PLAINS. MOISTENING WITH THE SW WIND ACROSS LAKE
MI HAS BROUGH LOW CLOUDS INTO FAR ERN UPPER MI...S AND E FROM ISQ TO
ERY. A BAND OF CLOUDS HAS ALSO DEVELOPED NE FROM THE BAY OF GREEN
BAY. UPSTREAM A LARGER AREA OF LOW CLOUDS FROM ERN MN AND FAR WRN WI
WAS GRADUALLY LIFTING TO THE NNE TO HYR-EAU.
TODAY...HIGH RES MODELS 925 MB RH FCSTS...IN LINE WITH CURRENT
TRENDS...SUGGEST THAT THE CLOUDS OVER NW WI WILL GRADUALLY SPREAD
INTO THE SW PORTION OF UPPER MI TODAY BUT THIN OUT OVER CNTRL
AREAS...ESPECIALLY WHERE DOWNSLOPE SW WINDS PREVAIL. THE CLOUDS OVER
THE ERN CWA ARE EXPECTED TO PUSH FARTHER TO THE EAST. EVEN WITH
LIMITED DAYTIME MIXING AS TEMPS CLIMB INTO THE UPPER 20S TO AROUND
30...WINDS WILL BECOME GUSTY TO AROUND 25-30 MPH.
TONIGHT...A SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WILL HELP
DRAG A WEAK COLD FRONT INTO LAKE SUPERIOR. 850-700 MB FGEN
ASSOCIATED WITH THE FRONT ALONG WITH WEAK ISENTROPIC LIFT ALONG WITH
MOISTENING FROM WSW WINDS ACROSS LAKE SUPERIOR WILL SUPPORT A SLIGHT
CHANCE FOR LIGHT SNOW SHOWERS OR FLURRIES INTO THE KEWEENAW. WITH
THE MOIST LAYER ONLY TO AROUND -10C...SOME FZDZ MAY ALSO BE
POSSIBLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM EST TUE JAN 5 2016
MAY SEE A FEW LIGHT LES SHOWERS OVER THE NRN PORTIONS OF THE
KEWEENAW WED MORNING WITH SW WINDS AND 850MB TEMPS AROUND -9C...BUT
NOT SIGNIFICANT ACCUMULATIONS. A TROUGH AND SFC FRONT STALL OUT OVER
THE AREA ON WED AND STAY INTO THU NIGHT. DEVELOPMENT OF LOW-MID
LEVEL FGEN FORCING WILL PROMOTE AN ELONGATED AREA OF LIGHT SNOW OVER
MAINLY WRN/NWRN UPPER MI WED AFTERNOON AND EVENING. A SHORTWAVE AND
WAA WILL THEN LEAD TO WIDESPREAD LIGHT SNOW WED NIGHT INTO
THU...ENDING TIME UNCERTAIN WITH DIFFERING MODEL SOLUTIONS. EXPECT
SNOW TO LIQUID RATIOS AROUND 10 TO 1 GIVEN MOST OF THE WEAK LIFT IS
BELOW THE DGZ...WHICH WHEN COMBINED WITH TOTAL QPF AMOUNTS OF 0.10-
0.25 INCHES (LOWEST SE AND GREATEST OVER THE W AND NW) EXPECT
GENERALLY 1 TO JUST OVER 2 INCHES OF SNOW IN THE 24-30 HOUR PERIOD.
ANOTHER PERIOD OF LIGHT AND INSIGNIFICANT SNOW IS EXPECTED FRI AND
SAT AS A WEAK LOW MOVES FROM MO AT 12Z FRI TO QUEBEC OR JAMES BAY
(DEPENDING ON MODEL SOLUTION) BY 00Z SUN. STILL LOOKS LIKE BEST
FORCING/PRECIP WILL BE OVER THE ERN AND MAYBE SRN UPPER MI IN THE
FRI AFTERNOON/FRI NIGHT TIME FRAME. STILL SEEING MODEL DIFFERENCES
ON TIMING. COULD SEE SOME RAIN MIX IN FRI AFTERNOON OVER SERN UPPER
MI AS WET BULB ZERO HEIGHTS RISE WITH HIGHS IN THE MID 30S. OVERALL
ONLY EXPECTING A VERY MINOR 1-3 INCHES OF SNOW OVER 36 HOURS.
MAIN STORY IN THE LONG TERM IS THAT MODEL PERSIST IN SHOWING AN
ACTIVE WAVE MOVING INTO THE AREA SAT NIGHT AND DEEPENING INTO A
CLOSED UPPER LOW OVER OR NEAR THE CWA LATE SUN AND SUN NIGHT. 850MB
TEMPS AS LOW AS -25C ARE CO-LOCATED WITH THE LOW. MODELS ALSO
CONTINUE TO SHOW ANOTHER WAVE MOVING IN MID NEXT WEEK...WHICH WILL
REINFORCE THE COLD AIR. TEMPS WILL GO FROM HIGHS IN THE UPPER 20S TO
MID 30S AND LOWS IN THE 20S LATE IN THE WEEK TO HIGHS IN THE SINGLE
DIGITS TO TEENS ABOVE ZERO AND LOWS IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO EARLY NEXT WEEK. NW-W WIND SNOWBELTS WILL CERTAINLY SEE
PERSISTENT LES SAT NIGHT THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...BUT NOT EXPECTING WARNING AMOUNTS AT THIS TIME DUE TO SMALL
FLAKE SIZE GIVEN VERY COLD TEMPS (CLOUD LAYER COLDER THAN THE
PREFERRED DGZ). THAT COLD AIR WILL ALSO MARK THE FIRST TIME OUR
OFFICE WILL FALL BELOW ZERO SINCE MARCH 28...2015. THROUGH JANUARY
3...THAT MAKES A 281 DAY STREAK AND IS CURRENTLY TIED FOR THE 16TH
LONGEST STREAK. IF THE CURRENT FORECAST HOLDS...WE WILL MAKE IT TO
AROUND 288 OR 289 DAYS...WHICH WOULD BE RIGHT AROUND THE 9TH LONGEST
STREAK OF TEMPERATURES AT OR ABOVE ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1236 AM EST TUE JAN 5 2016
INCRSG SW WIND TNGT ABOVE LLVL INVRN ENHANCED BY NOCTURNAL COOLING
WL RESULT IN LLWS AT ALL 3 SITES THIS MRNG. WITH SOME DAYTIME
HEATING...EXPECT GUSTY SW WINDS BY LATE MRNG THRU THE AFTN. HOW
QUICKLY THIS SW FLOW TAPS MOISTER AIR WELL TO THE SW OF UPR MI IS
ANOTHER FCST CONCERN. RIGHT NOW...EXPECT VFR CONDITIONS TO PREVAIL
THRU TODAY...WITH DOWNSLOPE NATURE OF THE SW FLOW HELPING TO
MAINTAIN LOWER RH. BUT EVEN THE DRIER GUIDANCE HINTS LO CLDS WL
ARRIVE TNGT...SO FCST MVFR CIGS TO ARRIVE THIS EVNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EST MON JAN 4 2016
TIGHTENING PRES GRADIENT BTWN DEPARTING HIGH PRES RIDGE AND LOW PRES
MOVING OVER HUDSON BAY WILL RESULT IN SW WINDS INCREASING TO GALES
TONIGHT ACROSS LAKE SUPERIOR. THE GALES WILL CONTINUE TUE BEFORE
WINDS BEGIN TO DIMINISH TUE NIGHT. WINDS WILL DIMINISH FURTHER
WED/THU TO MOSTLY UNDER 20KT AS A LOW PRES TROF SETTLES OVER THE
UPPER GREAT LAKES. WINDS WILL INCREASE SOME ON FRI/SAT AS LOW PRES
LIFTS NE INTO THE GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265>267.
GALE WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR LSZ162.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LSZ263-264.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ243-244.
LAKE MICHIGAN...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
308 AM EST TUE JAN 5 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 359 PM EST MON JAN 4 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THAT THE TROF THAT DROPPED
INTO THE GREAT LAKES REGION OVER THE WEEKEND IS WEAKENING AND
QUICKLY SHIFTING INTO NEW ENGLAND IN RESPONSE TO A STRONG RIDGE
MOVING OUT OVER THE PLAINS AND SCNTRL CANADA. 12HR 500MB HEIGHT
RISES WERE 90M/160M AT KINL/CWPL RESPECTIVELY AT 12Z TODAY. THE
ASSOCIATED SFC HIGH PRES RIDGE IS ALREADY EXITING TO THE E OF THE
FCST AREA AND SW RETURN FLOW IS RAPIDLY INCREASING TO THE W AND NW
IN THE TIGHTENING PRES GRADIENT BTWN THE DEPARTING RIDGE AND LOW
PRES APPROACHING HUDSON BAY. AS A RESULT...LINGERING/DIMINISHING LES
OFF LAKE SUPERIOR HAS MOSTLY SHIFTED OFFSHORE EARLY THIS AFTN WITH
ONLY A FEW RESIDUAL FLURRIES OVER THE NCNTRL. FLURRIES HAVE ALSO
MOVED ONSHORE AROUND MENOMINEE AS WINDS VEER OVER NRN LAKE MI.
A QUIET SHORT TERM PORTION OF THE FCST IS SHAPING UP...AT LEAST PCPN-
WISE. SW FLOW WILL DOMINATE BTWN THE HIGH PRES RIDGE SHIFTING TO THE
E COAST AND LOW PRES TRACKING ACROSS HUDSON BAY. DESPITE
WAA/ISENTROPIC ASCENT...FCST SOUNDINGS SHOW COLUMN REMAINING VERY
DRY...SO PCPN WON`T BE AN ISSUE UNDER THE WAA REGIME TONIGHT/TUE.
HOWEVER...AS WINDS VEER TO THE SW OVER NRN LAKE MI...SOME FLURRIES
SHOULD BRUSH AREAS NEAR LAKE MI THIS EVENING...AND ONCE THE SW FLOW
LOCKS IN...THE WRN EDGE OF LIGHT LES/FLURRIES MAY OCCASIONALLY
AFFECT SE LUCE COUNTY OVERNIGHT. ELSEHWERE...AN ISSUE TONIGHT/TUE IS
THE POTENTIAL FOR LOW CLOUDS TO DEVELOP AS NAM/RAP SHOW SHALLOW
MOISTENING IN THE NEAR SFC LAYER...THE RAP MUCH SOONER THAN THE NAM.
SFC OBS/3.9 MICRON IMAGERY DO SHOW LOW STRATUS OVER MUCH OF IA INTO
PORTIONS OF SCNTRL MN THIS AFTN. TRAJECTORIES INITIALLY CARRY THIS
STRATUS NORTHWARD...BUT OVER TIME THESE LOW CLOUDS MAY SLIP INTO THE
HIGH TERRAIN OF WRN UPPER MI LATE TONIGHT OR TUE MORNING. WILL WAIT
TO SEE HOW THE STRATUS EVOLVES THIS EVENING WITHIN STRENGTHENING LOW-
LEVEL FLOW BEFORE SHIFTING TO A MUCH MORE PESSIMISTIC SKY COVER FCST
OVER THE HIGHER TERRAIN OF THE W HALF. ON TUE...TIGHT PRES GRADIENT
WILL LEAD TO GUSTY WINDS. LIMITED MIXING DEPTH WILL WORK TO KEEP
WINDS IN CHECK...BUT STILL EXPECT SOME GUSTS TO 30-35MPH OVER THE
HIGHER TERRAIN...DOWNSLOPE AREAS NEAR LAKE SUPERIOR AND DOWNWIND OF
LAKE MICHIGAN.
AS FOR TEMPS...TEMPS WILL HAVE A CHANCE TO FALL INITIALLY THIS
EVENING BEFORE GRADIENT TIGHTENS. TOUGH TO SAY HOW LOW TEMPS WILL
GET...BUT THE FAR E SHOULD HAVE THE BEST CHANCE FOR A QUICK FALL
THIS EVENING BEFORE CLOUDS AND/OR WINDS INCREASE AS THAT AREA IS
CLOSER TO THE DEPARTING HIGH PRES RIDGE. WILL SHOW TEMPS AS LOW AS
AROUND 5F ABOVE IN LUCE COUNTY/PORTIONS OF SCHOOLCRAFT COUNTY.
TRADITIONAL COLD SPOTS OVER THE INTERIOR W SHOULD SLIP JUST BLO 10F.
EXPECT HIGHS ON TUE IN THE MID/UPPER 20S FOR THE MOST PART.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 306 AM EST TUE JAN 5 2016
MAY SEE A FEW LIGHT LES SHOWERS OVER THE NRN PORTIONS OF THE
KEWEENAW WED MORNING WITH SW WINDS AND 850MB TEMPS AROUND -9C...BUT
NOT SIGNIFICANT ACCUMULATIONS. A TROUGH AND SFC FRONT STALL OUT OVER
THE AREA ON WED AND STAY INTO THU NIGHT. DEVELOPMENT OF LOW-MID
LEVEL FGEN FORCING WILL PROMOTE AN ELONGATED AREA OF LIGHT SNOW OVER
MAINLY WRN/NWRN UPPER MI WED AFTERNOON AND EVENING. A SHORTWAVE AND
WAA WILL THEN LEAD TO WIDESPREAD LIGHT SNOW WED NIGHT INTO
THU...ENDING TIME UNCERTAIN WITH DIFFERING MODEL SOLUTIONS. EXPECT
SNOW TO LIQUID RATIOS AROUND 10 TO 1 GIVEN MOST OF THE WEAK LIFT IS
BELOW THE DGZ...WHICH WHEN COMBINED WITH TOTAL QPF AMOUNTS OF 0.10-
0.25 INCHES (LOWEST SE AND GREATEST OVER THE W AND NW) EXPECT
GENERALLY 1 TO JUST OVER 2 INCHES OF SNOW IN THE 24-30 HOUR PERIOD.
ANOTHER PERIOD OF LIGHT AND INSIGNIFICANT SNOW IS EXPECTED FRI AND
SAT AS A WEAK LOW MOVES FROM MO AT 12Z FRI TO QUEBEC OR JAMES BAY
(DEPENDING ON MODEL SOLUTION) BY 00Z SUN. STILL LOOKS LIKE BEST
FORCING/PRECIP WILL BE OVER THE ERN AND MAYBE SRN UPPER MI IN THE
FRI AFTERNOON/FRI NIGHT TIME FRAME. STILL SEEING MODEL DIFFERENCES
ON TIMING. COULD SEE SOME RAIN MIX IN FRI AFTERNOON OVER SERN UPPER
MI AS WET BULB ZERO HEIGHTS RISE WITH HIGHS IN THE MID 30S. OVERALL
ONLY EXPECTING A VERY MINOR 1-3 INCHES OF SNOW OVER 36 HOURS.
MAIN STORY IN THE LONG TERM IS THAT MODEL PERSIST IN SHOWING AN
ACTIVE WAVE MOVING INTO THE AREA SAT NIGHT AND DEEPENING INTO A
CLOSED UPPER LOW OVER OR NEAR THE CWA LATE SUN AND SUN NIGHT. 850MB
TEMPS AS LOW AS -25C ARE CO-LOCATED WITH THE LOW. MODELS ALSO
CONTINUE TO SHOW ANOTHER WAVE MOVING IN MID NEXT WEEK...WHICH WILL
REINFORCE THE COLD AIR. TEMPS WILL GO FROM HIGHS IN THE UPPER 20S TO
MID 30S AND LOWS IN THE 20S LATE IN THE WEEK TO HIGHS IN THE SINGLE
DIGITS TO TEENS ABOVE ZERO AND LOWS IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO EARLY NEXT WEEK. NW-W WIND SNOWBELTS WILL CERTAINLY SEE
PERSISTENT LES SAT NIGHT THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...BUT NOT EXPECTING WARNING AMOUNTS AT THIS TIME DUE TO SMALL
FLAKE SIZE GIVEN VERY COLD TEMPS (CLOUD LAYER COLDER THAN THE
PREFERRED DGZ). THAT COLD AIR WILL ALSO MARK THE FIRST TIME OUR
OFFICE WILL FALL BELOW ZERO SINCE MARCH 28...2015. THROUGH JANUARY
3...THAT MAKES A 281 DAY STREAK AND IS CURRENTLY TIED FOR THE 16TH
LONGEST STREAK. IF THE CURRENT FORECAST HOLDS...WE WILL MAKE IT TO
AROUND 288 OR 289 DAYS...WHICH WOULD BE RIGHT AROUND THE 9TH LONGEST
STREAK OF TEMPERATURES AT OR ABOVE ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1236 AM EST TUE JAN 5 2016
INCRSG SW WIND TNGT ABOVE LLVL INVRN ENHANCED BY NOCTURNAL COOLING
WL RESULT IN LLWS AT ALL 3 SITES THIS MRNG. WITH SOME DAYTIME
HEATING...EXPECT GUSTY SW WINDS BY LATE MRNG THRU THE AFTN. HOW
QUICKLY THIS SW FLOW TAPS MOISTER AIR WELL TO THE SW OF UPR MI IS
ANOTHER FCST CONCERN. RIGHT NOW...EXPECT VFR CONDITIONS TO PREVAIL
THRU TODAY...WITH DOWNSLOPE NATURE OF THE SW FLOW HELPING TO
MAINTAIN LOWER RH. BUT EVEN THE DRIER GUIDANCE HINTS LO CLDS WL
ARRIVE TNGT...SO FCST MVFR CIGS TO ARRIVE THIS EVNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EST MON JAN 4 2016
TIGHTENING PRES GRADIENT BTWN DEPARTING HIGH PRES RIDGE AND LOW PRES
MOVING OVER HUDSON BAY WILL RESULT IN SW WINDS INCREASING TO GALES
TONIGHT ACROSS LAKE SUPERIOR. THE GALES WILL CONTINUE TUE BEFORE
WINDS BEGIN TO DIMINISH TUE NIGHT. WINDS WILL DIMINISH FURTHER
WED/THU TO MOSTLY UNDER 20KT AS A LOW PRES TROF SETTLES OVER THE
UPPER GREAT LAKES. WINDS WILL INCREASE SOME ON FRI/SAT AS LOW PRES
LIFTS NE INTO THE GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ263>267.
GALE WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR LSZ162.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ243-244.
LAKE MICHIGAN...
GALE WARNING FROM 7 AM THIS MORNING TO 1 AM EST WEDNESDAY FOR
LMZ221-248-250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1236 AM EST TUE JAN 5 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 359 PM EST MON JAN 4 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THAT THE TROF THAT DROPPED
INTO THE GREAT LAKES REGION OVER THE WEEKEND IS WEAKENING AND
QUICKLY SHIFTING INTO NEW ENGLAND IN RESPONSE TO A STRONG RIDGE
MOVING OUT OVER THE PLAINS AND SCNTRL CANADA. 12HR 500MB HEIGHT
RISES WERE 90M/160M AT KINL/CWPL RESPECTIVELY AT 12Z TODAY. THE
ASSOCIATED SFC HIGH PRES RIDGE IS ALREADY EXITING TO THE E OF THE
FCST AREA AND SW RETURN FLOW IS RAPIDLY INCREASING TO THE W AND NW
IN THE TIGHTENING PRES GRADIENT BTWN THE DEPARTING RIDGE AND LOW
PRES APPROACHING HUDSON BAY. AS A RESULT...LINGERING/DIMINISHING LES
OFF LAKE SUPERIOR HAS MOSTLY SHIFTED OFFSHORE EARLY THIS AFTN WITH
ONLY A FEW RESIDUAL FLURRIES OVER THE NCNTRL. FLURRIES HAVE ALSO
MOVED ONSHORE AROUND MENOMINEE AS WINDS VEER OVER NRN LAKE MI.
A QUIET SHORT TERM PORTION OF THE FCST IS SHAPING UP...AT LEAST PCPN-
WISE. SW FLOW WILL DOMINATE BTWN THE HIGH PRES RIDGE SHIFTING TO THE
E COAST AND LOW PRES TRACKING ACROSS HUDSON BAY. DESPITE
WAA/ISENTROPIC ASCENT...FCST SOUNDINGS SHOW COLUMN REMAINING VERY
DRY...SO PCPN WON`T BE AN ISSUE UNDER THE WAA REGIME TONIGHT/TUE.
HOWEVER...AS WINDS VEER TO THE SW OVER NRN LAKE MI...SOME FLURRIES
SHOULD BRUSH AREAS NEAR LAKE MI THIS EVENING...AND ONCE THE SW FLOW
LOCKS IN...THE WRN EDGE OF LIGHT LES/FLURRIES MAY OCCASIONALLY
AFFECT SE LUCE COUNTY OVERNIGHT. ELSEHWERE...AN ISSUE TONIGHT/TUE IS
THE POTENTIAL FOR LOW CLOUDS TO DEVELOP AS NAM/RAP SHOW SHALLOW
MOISTENING IN THE NEAR SFC LAYER...THE RAP MUCH SOONER THAN THE NAM.
SFC OBS/3.9 MICRON IMAGERY DO SHOW LOW STRATUS OVER MUCH OF IA INTO
PORTIONS OF SCNTRL MN THIS AFTN. TRAJECTORIES INITIALLY CARRY THIS
STRATUS NORTHWARD...BUT OVER TIME THESE LOW CLOUDS MAY SLIP INTO THE
HIGH TERRAIN OF WRN UPPER MI LATE TONIGHT OR TUE MORNING. WILL WAIT
TO SEE HOW THE STRATUS EVOLVES THIS EVENING WITHIN STRENGTHENING LOW-
LEVEL FLOW BEFORE SHIFTING TO A MUCH MORE PESSIMISTIC SKY COVER FCST
OVER THE HIGHER TERRAIN OF THE W HALF. ON TUE...TIGHT PRES GRADIENT
WILL LEAD TO GUSTY WINDS. LIMITED MIXING DEPTH WILL WORK TO KEEP
WINDS IN CHECK...BUT STILL EXPECT SOME GUSTS TO 30-35MPH OVER THE
HIGHER TERRAIN...DOWNSLOPE AREAS NEAR LAKE SUPERIOR AND DOWNWIND OF
LAKE MICHIGAN.
AS FOR TEMPS...TEMPS WILL HAVE A CHANCE TO FALL INITIALLY THIS
EVENING BEFORE GRADIENT TIGHTENS. TOUGH TO SAY HOW LOW TEMPS WILL
GET...BUT THE FAR E SHOULD HAVE THE BEST CHANCE FOR A QUICK FALL
THIS EVENING BEFORE CLOUDS AND/OR WINDS INCREASE AS THAT AREA IS
CLOSER TO THE DEPARTING HIGH PRES RIDGE. WILL SHOW TEMPS AS LOW AS
AROUND 5F ABOVE IN LUCE COUNTY/PORTIONS OF SCHOOLCRAFT COUNTY.
TRADITIONAL COLD SPOTS OVER THE INTERIOR W SHOULD SLIP JUST BLO 10F.
EXPECT HIGHS ON TUE IN THE MID/UPPER 20S FOR THE MOST PART.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 323 PM EST MON JAN 4 2016
NO SIGNIFICANT WEATHER CONCERNS FOR THE LONG TERM FORECAST...BUT
THERE WILL BE SEVERAL NUISANCE EVENTS THAT COULD LEAD TO OCCASIONAL
PERIODS OF SLIPPERY ROADS.
HIGH PRESSURE WILL BE OVER THE ATLANTIC SEABOARD AT THE START OF
THE LONG TERM PERIOD...WHILE A SHORTWAVE AND SURFACE LOW MOVE
THROUGH SOUTHERN HUDSON BAY. A WEAKENING TROUGH ASSOCIATED WITH THE
LOW WILL BE SLIDING SOUTHEAST TOWARDS THE AREA TUESDAY NIGHT AND
INTO WEDNESDAY (ACROSS NORTHWEST ONTARIO)...EVENTUALLY SETTLING
OVER WESTERN LAKE SUPERIOR. THAT TROUGH WILL REMAIN NEARLY
STATIONARY THROUGH THURSDAY...AS A WEAK SHORTWAVE LIFTS NORTHEAST
ACROSS THE UPPER GREAT LAKES REGION. EXPECT LIMITED PRECIPITATION
ALONG THE FRONT TUESDAY NIGHT INTO WEDNESDAY BEFORE THE SHORTWAVE
MOVES THROUGH...WITH THE BEST CHANCES TIED TO SOME LAKE ENHANCEMENT
NEAR THE KEWEENAW PENINSULA. THE GENERAL IDEA WITH THE HIGHER
RESOLUTION MODELS IS TO KEEP THE TROUGH OVER WESTERN LAKE SUPERIOR
AND THE HEAVIER BAND JUST BRUSHING THE NORTHERN PORTIONS OF
KEWEENAW COUNTY. WILL FOLLOW THAT IDEA WITH THE POPS/SNOW
FORECAST...BUT WILL NEED TO KEEP AN EYE ANY TRENDS TO THE SOUTH AS
THAT WOULD LEAD TO SOME HEAVIER SNOW AFFECTING KEWEENAW COUNTY.
OTHERWISE...EXPECT LOW CLOUDS TO SPREAD INTO THE AREA UNDER THE
STRONG INVERSION JUST ABOVE 900MB TUESDAY EVENING...ASSUMING THEY
DON/T OCCUR BEFORE THAT AS SHOWN ON THE NAM. WITH THE LOW CLOUD
POTENTIAL AND CLOUDS FROM THE TROUGH...SHOULD SEE A MOSTLY CLOUDY
PERIOD TUESDAY NIGHT INTO WEDNESDAY.
PRECIPITATION SHOULD MOVE INTO THE WESTERN U.P. WEDNESDAY
AFTERNOON/EVENING ALONG THE STALLED TROUGH AND ASSOCIATED WITH
INCREASING MOISTURE AND MID LEVEL Q-VECTOR CONVERGENCE WITH THE
SHORTWAVE. WILL LIKELY SEE TWO WAVES...WITH THE FIRST AN ELONGATED
WSW TO ENE AREA OF SNOW STRETCHING ACROSS THE WEST/CENTRAL U.P. AND
ASSOCIATED WITH 850-750MB FGEN FORCING. THE SECOND PUSH ARRIVES
LATE WEDNESDAY NIGHT INTO THURSDAY AS THE SHORTWAVE AND 850-700MB
WARM AIR ADVECTION PUSHES THROUGH. EXPECT ALL OF THIS PRECIP TO
FALL AS SNOW LATE WEDNESDAY AFTERNOON INTO THURSDAY...BUT WITH MUCH
OF THE FORCING BELOW THE DGZ...THINK SNOW-TO-LIQUID RATIOS WILL BE
RIGHT AROUND 10-1 FOR MUCH OF THE EVENT (MAYBE SLIGHTLY LOWER
INITIALLY AND SLIGHTLY HIGHER TOWARDS THE END). THUS...WITH QPF
AMOUNTS OF 0.1 TO 0.25 OVER THE WEST/CENTRAL U.P. WOULD EXPECT
SNOWFALL AMOUNTS AROUND 2 INCHES FOR MUCH OF THE WEST/CENTRAL U.P.
SHOULD SEE A BRIEF BREAK BEFORE THE NEXT WAVE OF LIGHT PRECIPITATION
MOVES NORTHEAST INTO THE AREA FRIDAY INTO SATURDAY AS A WEAK LOW
LIFTS FROM MISSOURI AT 12Z FRIDAY TO JAMES BAY BY 12Z SUNDAY. AT
THIS POINT...IT LOOKS LIKE THE BEST FORCING WILL BE OVER THE EASTERN
U.P. WITH THE BEST PUSH OF SNOW MOVING THROUGH DURING THE DAY ON
FRIDAY (GENERALLY 1-3 INCHES). THERE MAY BE ENOUGH LOW LEVEL WARMING
TO RAISE WETBULB0 HEIGHTS TO LEAD TO A LITTLE BIT OF RAIN MIXING IN
WITH THE SNOW ALONG THE BAY OF GREEN BAY SHORELINE SOUTH OF
ESCANABA...SO DID INCLUDE A SLIGHT CHANCE TO CHANCE OF RAIN THERE.
WHILE THE LOW IS FAIRLY WEAK AND BRINGS SOME LIGHT SNOW FRIDAY
INTO FRIDAY NIGHT...A STRONG WAVE FROM THE ARCTIC WILL BE DIVING
SOUTH ACROSS THE CANADIAN PRAIRIES AND BE MOVING TOWARDS THE GREAT
LAKES REGION FOR THE SECOND HALF OF THE WEEKEND AND FOR EARLY NEXT
WEEK. THAT WILL LEAD TO A SIGNIFICANT TRANSITION IN TEMPERATURES...
FROM THE LOWER 30S FOR THE LATER HALF OF THIS WEEK TO HIGHS IN THE
SINGLE DIGITS TO LOWER TEENS ABOVE ZERO ON MONDAY. THAT COLD AIR
WILL ALSO MARK THE FIRST TIME OUR OFFICE WILL FALL BELOW ZERO SINCE
MARCH 28...2015. THROUGH JANUARY 3...THAT MAKES A 281 DAY STREAK
AND IS CURRENTLY TIED FOR THE 16TH LONGEST STREAK. IF THE CURRENT
FORECAST HOLDS...WE WILL MAKE IT TO AROUND 288 OR 289 DAYS...WHICH
WOULD BE RIGHT AROUND THE 9TH LONGEST STREAK OF TEMPERATURES AT OR
ABOVE ZERO. THAT COLD AIR (850MB TEMPS FALLING TO -24C ON SUNDAY)
WILL KICK THE LAKE EFFECT MACHINE BACK INTO GEAR FOR THE AREA...BUT
THE COLD TEMPERATURES WILL KEEP THE CLOUD GENERALLY ABOVE THE DGZ
LEADING TO SMALLER FLAKES. THAT WILL KEEP SNOWFALL AMOUNTS IN CHECK
AND LIKELY WOULD ONLY SEE ADVISORY AMOUNTS IN THE TRADITIONAL
WEST-NORTHWEST WIND SNOWBELTS. THE GREATER IMPACT WITH THE SMALLER
FLAKES WILL BE THE REDUCED VISIBILITIES...ESPECIALLY IF THERE IS
ENOUGH WIND TO BLOW THE SNOW AROUND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1236 AM EST TUE JAN 5 2016
INCRSG SW WIND TNGT ABOVE LLVL INVRN ENHANCED BY NOCTURNAL COOLING
WL RESULT IN LLWS AT ALL 3 SITES THIS MRNG. WITH SOME DAYTIME
HEATING...EXPECT GUSTY SW WINDS BY LATE MRNG THRU THE AFTN. HOW
QUICKLY THIS SW FLOW TAPS MOISTER AIR WELL TO THE SW OF UPR MI IS
ANOTHER FCST CONCERN. RIGHT NOW...EXPECT VFR CONDITIONS TO PREVAIL
THRU TODAY...WITH DOWNSLOPE NATURE OF THE SW FLOW HELPING TO
MAINTAIN LOWER RH. BUT EVEN THE DRIER GUIDANCE HINTS LO CLDS WL
ARRIVE TNGT...SO FCST MVFR CIGS TO ARRIVE THIS EVNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EST MON JAN 4 2016
TIGHTENING PRES GRADIENT BTWN DEPARTING HIGH PRES RIDGE AND LOW PRES
MOVING OVER HUDSON BAY WILL RESULT IN SW WINDS INCREASING TO GALES
TONIGHT ACROSS LAKE SUPERIOR. THE GALES WILL CONTINUE TUE BEFORE
WINDS BEGIN TO DIMINISH TUE NIGHT. WINDS WILL DIMINISH FURTHER
WED/THU TO MOSTLY UNDER 20KT AS A LOW PRES TROF SETTLES OVER THE
UPPER GREAT LAKES. WINDS WILL INCREASE SOME ON FRI/SAT AS LOW PRES
LIFTS NE INTO THE GREAT LAKES REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ265>267.
GALE WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR LSZ162.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ263-264.
GALE WARNING FROM 6 AM THIS MORNING TO 1 AM EST WEDNESDAY FOR
LSZ243-244.
LAKE MICHIGAN...
GALE WARNING FROM 7 AM THIS MORNING TO 1 AM EST WEDNESDAY FOR
LMZ221-248-250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
932 PM CST WED JAN 6 2016
.UPDATE...
ISSUED AT 932 PM CST WED JAN 6 2016
SNOW WAS FALLING OVER MUCH OF NORTHWEST WISCONSIN AND WAS
INCREASING OVER NORTHERN MINNESOTA AS WELL. A NARROW BAND OF
HEAVIER SNOW DEVELOPED OVER THE TWIN PORTS INTO EXTREME NORTHERN
WISCONSIN THIS EVENING AND IT DUMPED A QUICK HALF TO ONE INCH OF
SNOW. WE HAVE INCREASED SNOWFALL OVER MUCH OF THE AREA
TONIGHT...BUT STILL HAVE MOST AREAS FROM 1 TO 2 INCHES BY MORNING.
THE 00Z NAM FORECASTS MORE SNOWFALL OVER FAR NORTHERN MINNESOTA
AFTER 06Z...AND WE ARE SEEING A NARROW BAND FORMING BETWEEN
BIGFORK AND ELY AS OF 930 PM. POPS WERE INCREASED TONIGHT INTO
THURSDAY MORNING AND WE BUMPED UP SNOWFALL FURTHER.
CALLS TO LEC/S IN OUR SOUTHWEST CWA REVEALED FEW FREEZING DRIZZLE
REPORTS AND THE LATEST RAP SHOWED SATURATION OCCURRING AROUND OR
SHORTLY AFTER 04Z RESULTING IN MAINLY SNOW. WE STILL THINK THERE
COULD BE SOME PATCHY FREEZING DRIZZLE OVERNIGHT AND CONTINUE TO
MENTION IN THE FORECAST.
UPDATE ISSUED AT 711 PM CST WED JAN 6 2016
AREA RADARS HAVE SHOWN ECHOES INCREASING IN BOTH COVERAGE AND
STRENGTH EARLY THIS EVENING...PARTICULARLY OVER NORTHERN
WISCONSIN. THIS IS ON TRACK WITH THE FORECAST AND LATEST GUIDANCE. WE
WILL ADJUST POPS THIS EVENING TO ACCOUNT FOR THE LATEST RADAR
TRENDS.
WE INCREASED POPS OVER OUR NORTHWEST CWA LATE TONIGHT AS SEVERAL
OF THE MODELS INDICATE AN ENHANCED BAND OF SNOW WILL BE POSSIBLE
THERE. THERE WILL BE SOME MAINLY WEAK FGEN IN THAT
AREA...ESPECIALLY IN THE LOW LEVELS. BASED ON STRENGTH OF THE
FORCING...WE INCREASED POPS TO LIKELY BUT ONLY NUDGED SNOW AMOUNTS
A FEW TENTHS OF AN INCH BOTH 06Z-12Z TONIGHT AND INTO THURSDAY
MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 334 PM CST WED JAN 6 2016
S/W TROF AXIS OVER IOWA LATE THIS AFTERNOON IS ACCOMPANIED BY A
FAIRLY LARGE PRECIP SHIELD..AND THIS WAVE WILL LIFT INTO WISCONSIN
TONIGHT. KMPX/KDLH/KARX RADARS INDICATE THAT PRECIP IS TRYING TO
EXPAND NORTHEASTWARD AHEAD OF THIS FEATURE IN MODESTLY STRONG
ASCENT..BRINGING A 4-8 HOUR PERIOD OF LIGHT PRECIP TO ROUGHLY THE
SOUTHEAST THIRD TO HALF OF THE DLH CWA TONIGHT/THUR MORNING. IN
GENERAL..AS THE WAVE LIFTS NEWD..DEEP LAYER SATURATION THROUGH A
SUFFICIENTLY DEEP LAYER BELOW -10C SHOULD RESULT IN MOST OF THE
PRECIP BEING LIGHT SNOW. HOWEVER..IN AREAS WHERE THE DRY LAYER
ALOFT IS SUFFICIENTLY DEEP TO NOT BE SATURATED..AREAS OF FREEZING
DRIZZLE/FLURRIES/FOG WILL PERSIST THROUGH TOMORROW. A GENERAL 1-2
INCH EVENT IS ANTICIPATED OVER MOST OF NW WISCONSIN TONIGHT/THUR
MORNING..WITH THE TWIN PORTS AND N SHORE AREAS BEING ON THE FAR
NORTHWEST EDGE OF THE MORE ORGANIZED PRECIP AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 334 PM CST WED JAN 6 2016
A SHORTWAVE WILL LIFT NORTHWARD THROUGH WISCONSIN THURSDAY NIGHT AND
FRIDAY IN THE BROAD SOUTHERLY UPPER LEVEL FLOW AHEAD OF AN UPPER
LEVEL LOW OVER THE CENTRAL PLAINS. LIGHT EASTERLY FLOW OVER THE
NORTHLAND WILL BECOME NORTHERLY DURING THIS TIME WHEN AN INVERTED
SURFACE TROUGH SLOWLY MOVES EAST THROUGH THE NORTHLAND. THE
SHORTWAVE AND TROUGH WILL BRING WIDESPREAD LIGHT TO MODERATE SNOW
TO THE NORTHLAND THURSDAY NIGHT AND FRIDAY. NORTHWEST WISCONSIN
AND THE ARROWHEAD ARE FORECAST TO GET ABOUT 2 TO 4 INCHES...WHILE
THE REST OF NE MINNESOTA ABOUT 1 TO 3 INCHES. EARLIER FORECASTS
HAD A MIXTURE OF RAIN AND SNOW...BUT THE LATEST GFS BUFR SOUNDINGS
SUGGEST THE PROFILES ARE SUFFICIENTLY DEEPLY SATURATED AND COLD TO
RESULT IN PRIMARILY SNOW.
A STRONG COLD NW FLOW COLD AIR BLAST WILL COME FRIDAY AND THROUGH
THE WEEKEND AS A DEEP UPPER LEVEL LOW DIGS OUT OF NORTHERN CANADA TO
ONTARIO AND THE NORTHERN GREAT LAKES. THE COLD NW FLOW WILL RESULT
IN LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH SHORE SNOW BELT REGION
THROUGH SUNDAY. LOWERED TEMPERATURES FOR THE LATE WEEKEND AND EARLY
NEXT WEEK BASED ON A BLEND OF THE GFS/CANADIAN/ECMWF.
TEMPERATURES WILL BOTTOM OUT ON SUNDAY WITH HIGHS MOSTLY BELOW
ZERO DEGREES.
THERE WILL LIKELY BE SOME TEMPERATURE RECOVERY MONDAY AND
TUESDAY...BUT HIGHS WILL STILL ONLY BE IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 545 PM CST WED JAN 6 2016
IFR/MVFR CONDITIONS COVERED THE NORTHLAND THIS EVENING WITH
PRECIPITATION JUST MOVING INTO NORTHWEST WISCONSIN. WE EXPECT
MAINLY IFR AND POSSIBLY LIFR CONDITIONS TO DOMINATE TONIGHT AS
PERSISTENT WAA/FGEN IMPACT THE AREA ALONG WITH A SHORTWAVE/TROUGH.
THE GUIDANCE IS IN PRETTY GOOD AGREEMENT DEVELOPING THE PRECIP
OVER CENTRAL MINNESOTA INTO NORTHERN WISCONSIN THIS EVENING AND
LIFTING IT NORTH WITH MORE DEVELOPMENT OVER NORTH CENTRAL TO
NORTHWEST MINNESOTA OVERNIGHT. PRECIP TYPE MAY BE A MIX OF
FREEZING DRIZZLE/SNOW BUT AS BETTER LIFT AND SATURATION OCCURS IT
WILL CHANGE OVER TO JUST SNOW. PRIOR TO THIS BAND OF PRECIP MOVING
NORTH...SOME PATCHY FREEZING DRIZZLE/FLURRIES WILL BE POSSIBLE
OVER MOST AREAS.
WE LEFT VSBYS RESTRICTIONS THROUGH THE PERIOD AS WE EXPECT FOG TO
CONTINUE/DEVELOP AFTER THE PRECIP LIGHTENS UP/MOVES OFF LATER
TONIGHT INTO THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 30 29 31 / 90 50 30 50
INL 21 28 26 28 / 60 70 50 40
BRD 27 30 27 32 / 50 30 30 50
HYR 26 33 28 34 / 80 50 70 70
ASX 27 33 28 34 / 90 50 70 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
416 PM CST TUE JAN 5 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM CST TUE JAN 5 2016
SHORT WAVE IN NORTHERN NEW MEXICO IS SLATED TO MOVE NORTHEAST AND
STRENGTHEN SLIGHTLY...BRINGING SOME DECENT LIFT AND LIGHT SNOW
STARTING MIDDAY WEDNESDAY. THERE WILL BE A COUPLE SHALLOW LAYERS
ALOFT WITH TEMPS SLIGHTLY ABOVE FREEZING...LEADING TO SOME MIXED
PRECIPITATION EARLY ON...BUT THESE TEMPS ALOFT COOL AS THE SHORT
WAVE WAVE APPROACHES...SO LIGHT SNOW IS MOSTLY EXPECTED WEDNESDAY
AFTERNOON. PRECIP AMOUNTS THROUGH 36 HOURS LOOK TO BE AROUND 0.05
TO 0.15 INCH... RESULTING IN A BROAD AREA OF UP TO 2 INCHES SNOW
BEFORE IT TAPERS OFF LATE WEDNESDAY NIGHT. OTHERWISE...TEMPS WILL
REMAIN ABOVE NORMAL AND WINDS WILL DIMINISH EARLY THIS EVENING AS
GRADIENT RELAXES. FORTUNATELY IT LOOKS LIKE WINDS SHOULD REMAIN
STEADY ENOUGH TO PREVENT ANY RADIATIONAL FOG IN THOSE AREAS THAT
HAVE REMAINED CLEAR OR THAT CLEAR OUT LATE THIS AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 416 PM CST TUE JAN 5 2016
VERY SIMILAR FORECAST IN THE EXTENDED RANGE WITH A PERIOD OF
SNOW...MIXED WITH FREEZING DRIZZLE OR DRIZZLE AT TIMES WEDNESDAY
NIGHT THRU FRIDAY NIGHT. THEN A PERIOD OF ARCTIC AIR AS SFC TEMPS
DROP BELOW FREEZING FOR THE FIRST TIME THIS WINTER SEASON.
WEDNESDAY NIGHT/THURSDAY CAN BE CHARACTERIZED AS A PERIOD OF
FREEZING DRIZZLE/DRIZZLE/FLURRIES OR LIGHT SNOW DEPENDING UPON IF
ANY ICE CRYSTALS FEED THE LOWER LEVELS OF THE ATMOSPHERE FROM THE
DEPARTING SYSTEM WEDNESDAY EVENING. LOW CLDS/FOG AND NEARLY STEADY
TEMPS WILL LEAD TO THIS TYPE OF SCENARIO WITH LITTLE CHANGE IN THE
AIR MASS. A SECONDARY SHORT WAVE WILL MOVE OUT OF THE SOUTHWEST
CONUS THURSDAY NIGHT AND PROVIDE ANOTHER PERIOD OF MAINLY LIGHT SNOW
FRIDAY/FRIDAY NIGHT. QPF AMTS AND SNOWFALL RATES WILL BE LOW WITH
BOTH WEDNESDAY AND FRIDAY SYSTEMS. THEREFORE...SNOWFALL AMTS FOR THE
WHOLE PERIOD MAY ADD UP TO 3-5 INCHES...ESPECIALLY IN SC/SE MN AND
INTO WC WI DEPENDING UPON THE TRACK OF THE UPPER LEVEL FEATURES.
ELSEWHERE...AMTS WILL BE LIMITED TO 1-2 INCHES OF SNOWFALL.
THE MAIN WX FEATURE IN THE EXTENDED PERIOD REMAINS THE ARCTIC AIR
MASS WHICH WILL LEAD TO OUR FIRST /ALL OF MPX CWA/ BELOW ZERO
READINGS SINCE LAST WINTER. CURRENTLY...MODELS HAVE THE CORE OF THIS
AIR MASS ORIGINATING NEAR THE NORTH POLE TODAY. THIS AIR MASS
WILL BREAK OFF AND MOVE SOUTHWARD ACROSS CANADA AND INTO THE
NORTHERN PLAINS/UPPER MIDWEST BY SUNDAY. -20C TO -30C 85H TEMPS
ARE ASSOCIATED WITH THIS AIR MASS WHICH WILL LEAD TO DAYTIME TEMPS
IN THE SINGLE DIGITS TO AROUND ZERO ON SUNDAY. THE EC HAS BEEN THE
COLDEST WITH THIS AIR MASS AND IT REMAINS THE COLDEST WITH THE
CURRENT 12Z RUN. SATURDAY WILL SEE TEMPS NEARLY STEADY OR FALL
INTO THE TEENS AND SINGLE DIGITS BY THE EVENING. WITH WINDS
GUSTING UP TO 20 TO 25 MPH AT TIMES...WIND CHILL VALUES WILL DROP
TO NEAR -20 TO -30F BY SUNDAY MORNING OVER A WIDE AREA OF WESTERN
AND SOUTHERN MN. LITTLE RECOVERY IS EXPECTED SUNDAY WITH WIND
CHILL VALUES STILL HOLDING BETWEEN -10 TO -25F.
SOME DIFFERENCES IN THE MODELS OCCUR NEXT WEEK. HOWEVER...ALL MODELS
CONTINUE THE COLDER AIR MASS REMAINING IN PLACE THRU THE WEEK. NOT
UNTIL THIS UPPER AIR PATTERN CHANGES TO MORE WESTERLY...DOES OUR
REGION RECOVER TO NEAR NORMAL TEMPS.
ONE ITEM TO NOTE...ALTHOUGH THIS AIR MASS IS COLD...IT IS NOT AN
ANOMALY FOR THE UPPER MIDWEST FOR THE SECOND AND THIRD WEEK OF
JANUARY. THIS IS TYPICAL FOR THIS TIME...AND LOWS BELOW ZERO ARE
EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1212 PM CST TUE JAN 5 2016
IFR CEILINGS AND VISIBILITIES IN FAR SWRN MN HAVE BEEN ERODING
THIS MORNING ON THE EAST AND NORTHEAST EDGES...WHICH IS RESULTING
IN SOME QUESTION OF THE EXTENT TO WHICH IT EXPANDS THIS EVENING
WITH NIGHTFALL. NAM SEEMS TO OVERDO IT THIS AFTERNOON...AND
LATEST RAP SEEMS MORE LIKELY...SPREADING NORTH AND NORTHEAST INTO
CENTRAL AND WEST CENTRAL MN THIS EVENING...INCLUDING KSTC...WHILE
KEEPING WISC AND ADJACENT PARTS OF MN IN VFR CONDITIONS. LATE
TONIGHT...THE RAP DRIES IT OUT OVER SW MN LATE TONIGHT...BUT AM
SKEPTICAL ABOUT THIS BEING CORRECT.
BOTTOM LINE IS IT LOOKS LIKE MVFR CEILINGS WILL BECOME WIDESPREAD
FROM SW INTO CENTRAL AND WEST CENTRAL MN THIS EVENING. HOWEVER...
IT IS QUITE UNCERTAIN WHETHER IFR CONDITIONS WILL DEVELOP LATER
TONIGHT. ALSO...TOWARD THE END OF THE PERIOD...LIGHT SNOW WILL
DEVELOP ACROSS SW MN LATE WED MORNING. SNOW SHOULD SPREAD NORTH
AND EAST WED AFTERNOON AND INTO WISC...BEYOND THE 18Z TAF END.
KMSP...
LOWS CLOUDS IN SW MN HAVE STAYED PUT FOR NOW...AND EVEN IF THEY DO
SPREAD TO THE NORTH AND NORTHEAST THIS EVENING...IT LOOKS LIKE
THEY SHOULD AVOID KMSP. AT MOST...FAR NORTHWEST METRO MIGHT SEE
THE MVFR CLOUDS THIS EVENING. MOST INDICATIONS ARE THAT MVFR CEILINGS
WILL SPREAD/DEVELOP INTO KMSP LATE TONIGHT BUT CONFIDENCE IN THIS
IS ONLY AVERAGE. LIGHT SNOW SHOULD ARRIVE MIDDAY WITH IFR CEILINGS
AND VISIBILITIES DURING MID AND LATE AFTERNOON. SOME FREEZING
DRIZZLE IS NOT OUT OF THE QUESTION WED AFTERNOON...AND WILL NOT BE
SURPRISED IF THERE ARE SOME LIFR VISIBILITIES IN SNOW LATE
WEDNESDAY AFTERNOON.
/OUTLOOK FOR KMSP/
THU...MVFR CIGS LIKELY. SLIGHT CHANCE -SN. WINDS SE 5-8 KTS.
FRI...MVFR CIGS LIKELY. -RA/-SN LIKELY. WINDS NE 5-10 KTS.
SAT...MVFR CIGS LIKELY. -SN ENDING. WINDS NW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...TDK
LONG TERM...JLT
AVIATION...TDK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1212 PM CST TUE JAN 5 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 541 AM CST TUE JAN 5 2016
ANOTHER DRY DAY IS EXPECTED WITH NEAR NORMAL TEMPS AND A MIX OF
CLOUD AND SUNSHINE.
THE CENTER OF A LARGE AREA OF HIGH PRESSURE HAS SETTLED IN ACROSS
THE OHIO VALLEY. THE HIGH EXTENDS FROM THE GULF TO THE NORTHEAST US.
MEANWHILE...MSLP IS FALLING IN THE DAKOTAS AS LONG WAVE TROUGHING
CONTINUES TO MOVE EAST FROM THE WESTERN CONUS. THE RESULT IS A
HEALTHY PRESSURE GRADIENT ACROSS THE AREA AND PRONOUNCED SOUTHWEST
FLOW. THE TEMPERATURE ADVECTION IS NEUTRAL TO SLIGHT WARM ADVECTION
BETWEEN 925MB-700MB...BUT THE MOISTURE ADVECTION IS EXPECTED TO
CONTINUE OVER THE NEXT 24 HOURS. THE AREA OF CLOUDS IN EASTERN MN
AND WESTERN WI WILL CONTINUE TO LIFT NORTHEAST WITH TIME...WHICH
WILL LIKELY LEAD TO ANOTHER CLEAR MORNING ACROSS MUCH OF EASTERN MN.
WESTERN MN IS CLEAR AT THE MOMENT...BUT CLOUD COVER IN NEBRASKA IS
EXPECTED TO LIFT NORTH WITH TIME LATE THIS MORNING.
EVENTUALLY...OVERCAST SKIES WILL SPREAD ACROSS THE AREA TONIGHT AND
THERE IS A SMALL CHANCE FOR FLURRIES OR DRIZZLE AS WE APPROACH
SUNRISE WEDNESDAY MORNING...HOWEVER...THE BEST CHANCE FOR PRECIP
WILL HOLD OFF UNTIL WEDNESDAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 541 AM CST TUE JAN 5 2016
LIGHT SNOW LOOKS LIKE SURE THING ON WEDNESDAY...AND THE LATE WEEK
SYSTEM APPEARS LESS AND LESS IMPRESSIVE WITH EVERY MODEL RUN.
MEANWHILE...THE COLDEST AIR OF THE SEASON WILL RUSH IN ON SATURDAY
BEHIND AN ARCTIC FRONT...WITH SUB-ZERO TEMPERATURES EXPECTED TO LAST
INTO NEXT WEEK.
WEDNESDAYS SYSTEM IS CURRENTLY COMING ONSHORE THE CALIFORNIA
COAST...AND WILL LIFT ACROSS THE REGION ON WEDNESDAY. FORECAST
SOUNDINGS SHOW DEEP SATURATION...BUT ONLY SLIGHT VEERING IN THE
WINDS...AND SPEEDS LESS THAN 30KTS THROUGHOUT THE TROPOPAUSE.
THEREFORE ONE CAN DEDUCE MINIMAL WARM AIR ADVECTION...AND MINIMAL
FORCING FOR ASCENT. THIS SUPPORTS PERSISTENT...WIDESPREAD LIGHT
SNOW...SO INCREASED POPS TO 90 PERCENT...AND CONTINUES WITH SNOWFALL
TOTALS OF 1 TO 2 INCHES. SINCE THE TOTAL WINDS ARE WEAK...ONE CAN
ASSUME THAT THE COMPONENT OF WINDS NORMAL TO THE ISOTHERMS IS ALSO
WEAK...SO THERE SHOULD NOT BE MUCH FRONTOGENETIC FORCING. THIS IS
INDEED THE CASE...SO DONT SEE THE POTENTIAL FOR HIGH END SNOWFALL
TOTALS...CERTAINLY NOT MORE THAN 3 OR 4 INCHES...WHICH MATCHES UP
WELL WITH WPC SNOWFALL PROBABILITIES.
LOOKING AHEAD...THE WEEKEND SYSTEM CONTINUES TO BRING A WINTRY MIX
OF SNOW AND RAIN ACROSS THE REGION...BUT QPF AMOUNTS ARE ONLY AROUND
A QUARTER OF AN INCH SO NOT ANTICIPATING MUCH IF ANY IMPACTS. A
COMPARISON OF THE 0-3KM MAX TEMPERATURES...TOGETHER WITH THE SURFACE
TEMPERATURES FROM THE GFS/ECMWF/NAM/GEM/SREF SHOWS THAT THE WARMEST
TEMPERATURES ARE AT THE SURFACE. WITHOUT AN ELEVATED WARM LAYER DO
NOT SEE THE RISK FOR FREEZING RAIN...BUT WITH ICE CRYSTALS COULD GET
SOME LIGHT DRIZZLE TOWARD THE TAIL END OF THE SYSTEM. ON SATURDAY
COLD AIR ADVECTION WILL BRING STRONG WINDS AND BELOW NORMAL
TEMPERATURES...WITH WIDESPREAD SUB-ZERO READINGS EXPECTED SATURDAY
NIGHT THROUGH AT LEAST EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1212 PM CST TUE JAN 5 2016
IFR CEILINGS AND VISIBILITIES IN FAR SWRN MN HAVE BEEN ERODING
THIS MORNING ON THE EAST AND NORTHEAST EDGES...WHICH IS RESULTING
IN SOME QUESTION OF THE EXTENT TO WHICH IT EXPANDS THIS EVENING
WITH NIGHTFALL. NAM SEEMS TO OVERDO IT THIS AFTERNOON...AND
LATEST RAP SEEMS MORE LIKELY...SPREADING NORTH AND NORTHEAST INTO
CENTRAL AND WEST CENTRAL MN THIS EVENING...INCLUDING KSTC...WHILE
KEEPING WISC AND ADJACENT PARTS OF MN IN VFR CONDITIONS. LATE
TONIGHT...THE RAP DRIES IT OUT OVER SW MN LATE TONIGHT...BUT AM
SKEPTICAL ABOUT THIS BEING CORRECT.
BOTTOM LINE IS IT LOOKS LIKE MVFR CEILINGS WILL BECOME WIDESPREAD
FROM SW INTO CENTRAL AND WEST CENTRAL MN THIS EVENING. HOWEVER...
IT IS QUITE UNCERTAIN WHETHER IFR CONDITIONS WILL DEVELOP LATER
TONIGHT. ALSO...TOWARD THE END OF THE PERIOD...LIGHT SNOW WILL
DEVELOP ACROSS SW MN LATE WED MORNING. SNOW SHOULD SPREAD NORTH
AND EAST WED AFTERNOON AND INTO WISC...BEYOND THE 18Z TAF END.
KMSP...
LOWS CLOUDS IN SW MN HAVE STAYED PUT FOR NOW...AND EVEN IF THEY DO
SPREAD TO THE NORTH AND NORTHEAST THIS EVENING...IT LOOKS LIKE
THEY SHOULD AVOID KMSP. AT MOST...FAR NORTHWEST METRO MIGHT SEE
THE MVFR CLOUDS THIS EVENING. MOST INDICATIONS ARE THAT MVFR CEILINGS
WILL SPREAD/DEVELOP INTO KMSP LATE TONIGHT BUT CONFIDENCE IN THIS
IS ONLY AVERAGE. LIGHT SNOW SHOULD ARRIVE MIDDAY WITH IFR CEILINGS
AND VISIBILITIES DURING MID AND LATE AFTERNOON. SOME FREEZING
DRIZZLE IS NOT OUT OF THE QUESTION WED AFTERNOON...AND WILL NOT BE
SURPRISED IF THERE ARE SOME LIFR VISIBILITIES IN SNOW LATE
WEDNESDAY AFTERNOON.
/OUTLOOK FOR KMSP/
THU...MVFR CIGS LIKELY. SLIGHT CHANCE -SN. WINDS SE 5-8 KTS.
FRI...MVFR CIGS LIKELY. -RA/-SN LIKELY. WINDS NE 5-10 KTS.
SAT...MVFR CIGS LIKELY. -SN ENDING. WINDS NW 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...JRB
AVIATION...TDK
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
937 PM CST WED JAN 6 2016
.UPDATE:
Issued at 936 PM CST Wed Jan 6 2016
Scattered rain continues to move across the area this evening. We
got reports of flurries and light sleet with the onset of this
rain as the atmosphere evaporately cooled as the rain fell in the
dry air. No reports of accumulations have been reported thus far.
Still appears that rain will become more likely across central MO
late tonight per the HRRR and RAP as shortwave currently over
southern high Plains approaches the area. Precipitation type still
should be rain as warm air gets advected in ahead of system. RAP
is also showing an increase in low level moisture convergence over
central MO toward 12Z. Rest of forecast looks good.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CST Wed Jan 6 2016
Warm advection aloft is producing bands of weak showers across
Missouri and Illinois. Much of this precip isn`t reaching the
ground, however scattered traces and 0.01 inch rainfall amounts keep
popping up on the hourly precip map...so have kept slight chance in
the forecast across central and northeast MO and west central IL for
the rest of the afternoon. Expect the areal coverage of the showers
to increase through the night...particularly over central Missouri
late. However...the precipitation will be fighting dry air in the
lower 3000-4000ft of the atmosphere so expect the rain to be very
light...perhaps not much more than sprinkles until near sunrise.
Southerly flow and plenty of cloud cover should keep temperatures
warmer than last night. MOS temperatures in the low to mid 30s look
reasonable so have followed closely.
Carney
.LONG TERM: (Thursday through Next Wednesday)
Issued at 431 PM CST Wed Jan 6 2016
...Thursday through Saturday...
This is expected to be an active period with broad SW flow with a
couple short waves expected to affect the region. Upper flow is
initially split with polar jet well north of the US/Canadian border
and the subtropical jet digging out a broad trough across the wrn
CONUS as it dives down the West Coast...into the Rio Grand
Valley...across the nthrn Gulf of MX and eventually by the end of
the prd...up the East Coast.
Weak short wave ridging is fcst to exit the NErn FA early Thu mrng.
Very light rain and/or sprinkles should be ongoing across cntrl
MO by 12Z with a band possibly extending NW into W cntrl IL. This
band may reach as far SE as the NWrn portion of the STL metro
area. Light rain should continue across cntrl MO thru the mrng but
the main push of moisture assoc with the upper lvl support won`t
really arrive until aftn though. Rain is expected to slowly spread
NE thru the day but progress will be slow...likely taking all day
to overspread areas east of STL...as the system overcomes dry air
in the lower lvls. QPF ranges between 0.25 to 0.75 inches with the
higher amounts across cntrl MO where the best forcing and moisture
is expected to be. Trough axis passes late Thu night into Fri mrng
as the SFC low tracks from the sthrn Plains to NW MO. Precip
should lift NE thru the evng...ending across NErn zones after
midnight as the SFC low passes...though can`t rule out some
drizzle areawide. The SFC low is fcst to continue NE into the Grt
Lks by Sat mrng.
Another low amplitude mid lvl ridge builds in for Fri aftn and
Fri evng before heights begin falling again. The cold front extending
from the first SFC low is expected to become stnry across the CWA
Fri night in response to the second short wave approaching. This
system is fcst to track further south...though how far south is in
question. The NAM wants to deepen and close off the mid level
circulation Sat aftn/evng as it passes...taking the SFC low
across SErn MO and sthrn IL...which would give the area the best
chance for winter precip. But it is an outlier. The GFS is the
farthest NW taking the SFC low just NW of the STL metro...and the
ECMWF is somewhere in between. Guidance has trended NW with recent
systems so tend to lean towards the GFS solution. Rain assoc with
WAA is expected to dvlp across SErn MO Fri night and then lift NE
into sthrn IL Sat mrng...with lighter precip for cntrl and NE MO
and W cntrl IL. The heaviest QPF...on the order of 0.50 to 0.75
inches...should fall across SErn MO and sthrn IL. SFC low lifts NE
thru the CWA Sat allowing for decent CAA...esp drng the aftn.
There will likely be a nondiurnal temp trend on Sat...esp NW of
the STL metro area. I think the Schmocker rule will be in full
effect with this event meaning the precip should be ending as
temps get cold enough for a transition to snow. This system bears
watching though.
Temps will be above normal thru the prd with lows aoa normal daytime
highs both Thu and Fri nights.
It has been 10 days since the record setting rains so hoping the
half to one inch rainfall totals expected thru Sat evng do not cause
any additional flooding concerns. Even if the rain does cause
renewed flooding...it should remain minimal.
...Saturday night through Tuesday...
The system will continue to pull away Sat night with CAA in full
force in response to a 1030mb SFC ridge building in from the nthrn
Plains. Sun will be a true winter day with highs mid teens north
to low 30s south and a stiff NW wind. The center of the SFC high
drifts nearly overhead late Sun night into Mon mrng which sets
the stage for a cold night due to good radiational cooling. Min
temps by Mon mrng are expected to range from the mid single digits
north to mid teens south. Temps will already be moderating by
early next week approaching seasonal norms by Tue. A weak cold
front on Tue may drop temps a bit for Wed. Keep in mind that if
the area does receive snow Sat PM then areas with snow cover will
be even colder than the going fcst indicates.
2%
&&
.AVIATION: (For the 00z TAFs through 00z Thursday Evening)
Issued at 627 PM CST Wed Jan 6 2016
Patchy sprinkles expected this evening over the area with some
isolated reports of melting sleet. Will go with VCSH at KUIN and
KCOU initially and leave out of the St. Louis metro TAFS for now
as they appear to be skirting the terminals on radar at this
time. Otherwise expect slow lowering of the ceilings with rain
slowly moving into the terminals late tonight and tomorrow.
Ceilings should fall to MVFR or possibly IFR by the end of the TAF
period.
Specifics for KSTL: Isolated sprinkles are possible early this
evening, but chances are not high enough to include in the TAF at
this time. Otherwise expect a slow lowering of the ceiling tonight
into tomorrow before steady rain and MVFR ceilings move into late
tomorrow afternoon. Expect low MVFR or possibly IFR conditions to
move into the terminal toward the end of the period.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1114 PM CST MON JAN 4 2016
.DISCUSSION...
Issued at 340 PM CST MON JAN 4 2016
Near term concerns center around the stratus deck lying under the
western half of a departing surface high. The visible and 11u-3.9u
satellite imagery revealed how thin this cloud deck was over the CWA
and as a result we saw much scattering of the deck during the
afternoon hours. Do think the stratus will reform over northwest MO
this evening. However, also expect the clearing seen over central MO
will work its way northwest overnight. The latest RAP now is in line
with the clearing shown by NAM 950mb condensation pressure deficit
progs. Overnight shift will need to monitor for potential fog
development along the periphery of the stratus.
All operational progs continue to show a rather wet period starting
as early as Wednesday morning as the first in a serious of features
work their way through the Central Plains and Mid MO River Valley.
GFS, ECMWF and SREF are in synch timing-wise with the first
shortwave, currently lifting northeast out of AZ. Warm advection
zone preceding this feature will overspread the CWA Wednesday. Have
raised PoPs. Inspection of NAM/GFS Bufr soundings continue to
support a chance of mixed precipitation. Currently the models show a
minimal warm nose aloft so either light freezing rain or snow (no
warm nose) are possible. QPF will be quite light with either one,
but enough that travel problems are possible for the morning rush
commute to work.
While a second shortwave will arrive on Thursday the increasingly
moist isentropic ascent could yield areas of drizzle/patchy rain
overnight Wednesday so high chance PoPs used. Steady moderate warm
air advection through a deep layer will allow temperatures to remain
above freezing through Friday. So, precipitation will be all liquid.
Friday night could bring a mix of rain and snow to the region as the
deformation zone lifts through the region. Quite a bit of difference
between the strength of the upper system/associated surface low with
the GFS considerably stronger. Given how much energy remains back to
the southwest within an elongated longer upper trough have little
confidence in a strong or well developed surface low. So, have not
bit on the GFS snow output.
Much colder air filters into the region over the weekend with
temperatures struggling to recover on Saturday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1111 PM CST MON JAN 4 2016
Low-level cloud cover should remain just to the west of the terminal
sites over eastern Kansas through the overnight hours underneath a
ridge axis. Winds will turn southerly by early Tuesday morning with
winds increasing into the afternoon. Mid-level clouds will enter the
area throughout the afternoon hours with sustained winds out of the
south.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS GLASGOW MT
839 PM MST WED JAN 6 2016
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY...
UPDATE...PATCHY FOG AND LOW CLOUDS HAVE DEVELOPED OVER PART OF
NORTHEAST MONTANA THIS EVENING. THE LOW CLOUDS WERE NEAR THE NORTH
DAKOTA BORDER AT 03Z AND EXTENDS EAST INTO NORTH DAKOTA. LOW LEVEL
EAST WINDS WILL ALLOW THESE CLOUDS TO DRIFT WEST OVERNIGHT. WILL
ALSO SOME INCREASE IN THE PATCHY FOG. CURRENT FORECAST COVERS THIS
WELL. FORRESTER
PREVIOUS SHORT TERM FORECAST...
SHORT TERM FORECAST PERIOD FOCUSES ON THE NEXT ACCUMULATING
SNOWFALL SET TO SPREAD ACROSS NORTHEAST MONTANA THURSDAY THROUGH
LATE FRIDAY BEFORE A COLD AIR MASS MOVES OVER OUR REGION LATER
THIS WEEKEND.
BUT FIRST...TONIGHT...HAZY SURFACE CONDITIONS HAVE BEEN PREVALENT
AND PERSISTENT ACROSS NE MONTANA THROUGH MOST OF THE DAY. MANY
MODELS ARE ADVERTISING A QUICK RETURN TO LOWERED VISIBILITIES
THIS EVENING AND TONIGHT. NOT SURE IF IT WILL BE ABLE TO TAKE A
STRONG HOLD GIVEN THE EXPECTED MID AND LOW LEVEL CLOUD COVER...BUT
WENT AHEAD AND PUT FREEZING FOG IN THE FORECAST FOR MOST OF THE
LOWER ELEVATION AREAS 00Z TONIGHT THROUGH 18Z THURSDAY.
WITH PACIFIC MOISTURE ARRIVING FROM THE WEST AND SOUTHWEST...THE
ARCTIC AIR MASS PUSHING SOUTHWARD FROM THE CANADIAN PRAIRIE WILL
BE ENOUGH TO SET OFF A ROUND OF ACCUMULATING SNOW BEGINNING EARLY
THURSDAY OVER CENTRAL MONTANA. THIS ACTIVITY WILL GRADUALLY
SPREAD EASTWARD AND SOUTHEASTWARD THROUGH THE REMAINDER OF THE
STATE THROUGH SATURDAY. MODELS HAVE GENERALLY FALLEN INTO FAIRLY
GOOD CONSENSUS REGARDING THIS SNOW FALL AND ITS TIMING AND
AMOUNTS. GFS...GEM...AND OTHER LONG TERM MODELS ARE A BIT ON THE
GENEROUS SIDE WITH PRECIP WHILE THE SHORTER-TERM MODELS SUCH AS
THE NAM...SREF...AND HRRR LEAN A LITTLE TOWARD THE LIGHTER SIDE.
FOR THE FORECAST...CHOSE TO ERR ON THE SIDE OF CAUTION AND LEANED
SOMEWHAT TOWARD THE MORE GENEROUS MODELS. THIS GIVES A SNOWFALL
FORECAST OF 1 TO 2 INCHES FOR MANY LOCATIONS AND UP TO 3 INCHES
FOR THE LITTLE ROCKIES. GIVEN THAT THIS EVENT WILL BE SPREAD OUT
FOR ABOUT 36 HOURS...DO NOT SEE A NEED TO ISSUE ANY ADVISORY
HEADLINES FOR THIS.
THE LEADING EDGE OF THE COLD FRONT WILL BE NOTICEABLE THURSDAY
NIGHT AS SURFACE WINDS TURN STEADILY FROM THE NORTHWEST AND
INCREASE TO AROUND 15 KTS. LATER THIS WEEKEND...TEMPERATURES WILL
GRADUALLY DROP 10 TO 20 DEGREES COLDER THAN RECENTLY EXPERIENCED
WITH WIND CHILL VALUES APPROACHING -20 FROM THE EAST AND
NORTHEAST. BMICKELSON
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
PRIMARY IMPACTS ARE EXPECTED IN THE EARLY PORTION OF THE EXTENDED
THE GOING LONG TERM DISCUSSION AS DESCRIBED BELOW STANDS. THE ONLY
TWEAKS MADE WERE MINOR AND TO ADJUST THE FORECAST MORE IN LINE
WITH THE CURRENT CONSENSUS OF THE EXTENDED MODELS. GILCHRIST
PREVIOUS LONG TERM DISCUSSION...WITH WHAT IS STILL LOOKING LIKE
THE COLDEST AIR MASS SO FAR THIS SEASON TO SETTLE INTO THE REGION.
LINGERING SNOW SHOWERS FRIDAY NIGHT AND SATURDAY WILL GIVE WAY TO
ARCTIC TEMPERATURES AND PERSISTENT NORTHWEST WINDS AROUND 10 MPH.
HIGH TEMPERATURES ON SATURDAY WILL LIKELY REMAIN BELOW ZERO NORTH
OF THE MISSOURI RIVER AND NEAR OR JUST ABOVE ZERO DEGREES TO THE
SOUTH.
EXPECT A BITING COLD FOR SATURDAY NIGHT. A NICE SNOW PACK ALONG
WITH LIGHT WIND SPEEDS AROUND 10 MPH AND CLEAR OR PARTLY CLOUDY
SKIES WILL LEAD TO STRONG RADIATIONAL COOLING. MODEL 85OMB
TEMPERATURES IN THE -20S CELSIUS WILL REALIZE THEIR FULL
POTENTIAL IN SUCH CONDITIONS. ACTUAL LOW TEMPERATURES WILL LIKELY
RANGE IN THE -10S WITH SOME OF THE COLDEST LOCATIONS IN THE -20S.
WILL IN PARTICULAR WATCH THE CANADIAN AND NORTH DAKOTA BORDER
REGIONS WHERE 850MB TEMPERATURES ARE TO BE THE COLDEST. ONLY
MODEST RECOVERY IN TEMPERATURES IS IN THE CARDS FOR SUNDAY WITH
HIGHS APPROACHING ZERO AND THE SINGLE DIGITS ABOVE. FUTURE SHIFTS
MAY NEED TO CONSIDER A WIND CHILL ADVISORY AT SOME POINT IN THIS
PERIOD. ALTHOUGH WIND SPEEDS LOOK MARGINAL...THE EXTENT OF THE
COLD AIR COMBINED WITH WIND SPEEDS EVEN NEAR 10 MPH COULD JUSTIFY
ISSUANCE IN ORDER TO BETTER DRIVE THE IMPACTS.
FOR EARLY NEXT WEEK...TEMPERATURES WILL MODESTLY AND GRADUALLY
RECOVER FOR MOST LOCATIONS AS THE ARCTIC AIR MASS SHIFTS AWAY AND
WARMER 850MB TEMPERATURES MOVE OVER THE REGION FROM THE WEST.
HOWEVER...DUE TO EFFECTS FROM AN INVERSION LAYER...HIGHER TERRAIN
WILL BE THE FAVORED PLACES TO SEE IMPROVING TEMPERATURES WHILE
VALLEY LOCATIONS REMAIN THE COLDEST IN GENERAL.
UPPER FLOW WILL BECOME ORIENTED FROM NORTHWEST TO SOUTHEAST TOWARD
THE MIDDLE PORTION OF NEXT WEEK. WILL HAVE TO MONITOR SHORTWAVES
FOR POTENTIAL LIGHT SNOW. WHILE BOTH 00Z RUN OF OPERATIONAL ECMWF
AND GFS EACH HAVE QPF SOMETIME TUESDAY ACROSS A PORTION OF THE
AREA...ENSEMBLE SPREAD IN 500MB HEIGHTS IS RATHER LARGE...LENDING
TO REDUCED CONFIDENCE AND HIGHER UNCERTAINTY. WILL PLACE SLIGHT
CHANCE POPS AT THIS TIME FOR NOW. MALIAWCO
&&
.AVIATION...
A VARIETY OF FLIGHT CONDITIONS IS EXPECTED OVERNIGHT AT THE TAF
SITES DUE TO INTERMITTENT LOW CIGS AND PATCHY FREEZING FOG.
MVFR/IFR WILL BE MORE PREVALENT THOUGH EVEN WORSE CONDITIONS MAY
BRIEFLY BE OBSERVED FROM TIME TO TIME THIS EVENING INTO TONIGHT.
MVFR TO IFR CIGS AND VSBYS ARE EXPECTED TO CONTINUE INTO THURSDAY
DUE TO LIGHT SNOW OVERSPREADING THE AREA. EAST WINDS AROUND 5 TO
10 KTS WILL PERSIST INTO THE NIGHT. MALIAWCO
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1122 PM CST MON JAN 4 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 404 PM CST MON JAN 4 2016
THE PRIMARY FORECAST CHALLENGES WILL CENTER AROUND LOW STRATUS AND
FOG DEVELOPMENT...ALONG WITH POTENTIAL IMPACT OF CLOUDS/FOG ON
TEMPERATURES.
THIS AFTERNOON THROUGH TONIGHT...LOW STRATUS HAS BEEN SLOW TO ERODE
AND REMAINS ACROSS PORTIONS OF OUR EASTERN FORECAST AREA THIS
AFTERNOON. THESE LOW STRATUS CLOUDS ARE EXPECTED TO EXPAND BACK
ACROSS THE AREA OVERNIGHT AS MOIST SOUTHERLY WINDS KICK UP ACROSS
THE REGION. RECENT RUNS OF THE HRRR HAVE BEEN VERY AGGRESSIVE WITH
GRADUALLY DEVELOPING FOG ACROSS MUCH OF THE FORECAST AREA AS WE HEAD
THROUGH THE OVERNIGHT HOURS. THEREFORE...WILL FORECAST AREAS OF FOG
TONIGHT AND MAY EVEN END UP NEEDING A DENSE FOG HEADLINE SHOULD THE
FOG FORM AND BECOME DENSE ENOUGH. NOT ENOUGH CONFIDENCE THIS FAR OUT
TO ISSUE A HEADLINE AS OF THIS AFTERNOON...BUT WOULD NOT BE
SURPRISED IF A DENSE FOG HEADLINE IS EVENTUALLY NEEDED LATER TONIGHT.
TUESDAY...MOST FORECAST MODELS KEEP A MAJORITY OF OUR FORECAST AREA
STUCK UNDER A LOW STRATUS DECK THROUGHOUT THE DAY. SOUTHWESTERN
ZONES SEEM TO STAND THE BEST CHANCE AT CATCHING SOME LATE DAY
SUNSHINE...BUT NO GRANTEES AS THIS FOG/LOW CLOUD FORECAST IS VERY
CHALLENGING. FOG WILL BE AT ITS WORST DURING THE CLIMATOLOGICALLY
FAVORABLE TIME...TUESDAY MORNING...AND THEN SHOULD BEGIN TO LIFT
INTO MORE OF A LOW STRATUS BY LATER IN THE MORNING/AFTERNOON. THE
SOUTHERLY WINDS WILL ADVECT WARMER AIR INTO THE REGION...BUT WITH
THICK LOW CLOUDS TEMPERATURES MAY HAVE A DIFFICULT TIME RISING
MUCH...ESPECIALLY OVER SNOW COVERED AREAS. CONFIDENCE IN THE
TEMPERATURE FORECAST IS LOWER THAN NORMAL WITH A WIDE SPREAD IN
MODEL TEMPERATURES DEPENDING ON IF ANY SUN CAN POKE THROUGH THE
CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 404 PM CST MON JAN 4 2016
THIS 6-DAY PERIOD CAN BASICALLY BE BROKEN DOWN INTO 3 TIME
FRAMES WITH THEIR OWN UNIQUE HIGHLIGHTS/CHALLENGES...AND WILL
START OUT BY BREAKING THESE DOWN:
1) TUESDAY NIGHT-WEDNESDAY NIGHT: ALTHOUGH NO ACCUMULATING SNOW IS
CURRENTLY EXPECTED DURING THESE 36 HOURS DUE TO LACK OF SATURATION
ALOFT...THERE ARE LEGITIMATE CONCERNS FOR AT LEAST SOME SPOTTY
LIGHT FREEZING DRIZZLE/FREEZING RAIN MAINLY DURING THE NIGHT AND
EARLY MORNING HOURS. THERE COULD ALSO BE MORE FOG ISSUES AS
WELL...BUT GIVEN HOW UNCERTAIN/TRICKY FOG TRENDS CAN BE IN THIS
PATTERN...AND THAT WE ALREADY HAVE FOG MENTIONED IN THE SHORT TERM
PERIOD DESCRIBED ABOVE...WILL DEFER TO LATER SHIFTS TO INTRODUCE
ANY POSSIBLE NEED FOR FOG INTO THE OFFICIAL FORECAST FOR TUESDAY
NIGHT AND BEYOND.
2) THURSDAY DAYTIME-FRIDAY NIGHT: AS HAS BEEN THE CASE FOR THE
PAST SEVERAL DAYS...THIS 48-HOUR PERIOD STILL FEATURES THE
POTENTIAL "MAIN EVENT" OF THE WEEK IN TERMS OF POTENTIAL SNOW
ACCUMULATION. ALTHOUGH WE ARE CREEPING EVER-CLOSER...BECAUSE WE
ONLY ADVERTISE OFFICIAL SNOW ACCUMULATION FORECASTS THROUGH 72
HOURS...OUR CURRENT FORECAST DOES NOT INCLUDE ANY ACCUMULATION
DATA FOR THURSDAY NIGHT-FRIDAY...WHICH IS WHEN MOST SNOW IS
EXPECTED TO FALL. THAT BEING SAID...WITH THIS POSSIBLE SNOW EVENT
WITHIN 4 DAYS NOW...AND WITH MODELS SUCH AS THE 12Z ECMWF/GFS
SUGGESTING THAT AT LEAST A FEW INCHES COULD AFFECT PARTS OF THE
CWA...HAVE OPTED TO INTRODUCE A MENTION IN OUR LATEST HAZARDOUS
WEATHER OUTLOOK (HWOGID). OF COURSE...THERE IS STILL PLENTY OF
UNCERTAINTY ESPECIALLY REGARDING THE LOW-LEVEL TEMPERATURE PROFILE
AND JUST HOW QUICKLY/SLOWLY ESPECIALLY OUR SOUTHERN/SOUTHEAST
COUNTIES WILL CHANGE OVER FROM RAIN TO SNOW...AS RAIN COULD BE THE
PREDOMINANT PRECIPITATION TYPE MUCH OF THE TIME IN THIS AREA.
CONVERSELY...ALTHOUGH SNOW APPEARS TO BE THE MORE DOMINANT TYPE IN
ESPECIALLY NORTHERN/WEST-CENTRAL COUNTIES...THERE ARE QUESTIONS
HERE ABOUT HOW MUCH PRECIPITATION MIGHT ACTUALLY FALL COMPARED TO
COUNTIES FARTHER SOUTH AND EAST. THUS...IN THEORY...THIS COULD BE
A SITUATION WHERE CENTRAL PORTIONS OF THE CWA ACTUALLY SEE THE
HIGHEST SNOWFALL AMOUNTS IF TRENDS CONTINUE ON THEIR CURRENT
TRACK...WITH LESSER AMOUNTS NORTHWEST AND SOUTHEAST. STILL TOO
SOON TO SAY FOR SURE THOUGH...AND PLEASE NOTE THAT WE ARE 24-36
HOURS AWAY FROM ADVERTISING SNOW ACCUMULATION TOTALS THAT WILL
CAPTURE THE ENTIRE EVENT.
3) SATURDAY DAYTIME-MONDAY DAYTIME: THESE LAST 3 DAYS OF THE
FORECAST HAVE BEEN KEPT AS/INTRODUCED AS OFFICIALLY DRY...AS
ALTHOUGH IT`S NOT OUT OF THE QUESTION THAT SOME VERY LIGHT
SNOW/FLURRIES COULD MAYBE LINGER INTO AT LEAST SATURDAY MORNING
IN LATER FORECASTS (ESPECIALLY PER THE ECMWF SOLUTION)...THERE
APPEARS TO BE VERY LITTLE IF ANY CHANCE OF ANOTHER LEGITIMATE
WINTRY PRECIPITATION EVENT THROUGH THIS TIME. THAT MEANS THAT THE
MAIN STORY WILL TURN TOWARD COLDER-THAN-NORMAL TEMPERATURES.
ALTHOUGH MODELS ARE CERTAINLY NOT IN LOCK-STEP AT THIS DAY 5-7
RANGE (AS IS TYPICAL)...AT LEAST FOR NOW WE ARE AIMING HIGH
TEMPERATURES ONLY INTO THE 18-28 DEGREES RANGE ACROSS MOST OF THE
CWA...WHICH IS ROUGHLY 7-15 DEGREES BELOW AVERAGE/NORMAL FOR EARLY
JANUARY. IN TURN...OVERNIGHT LOW TEMPERATURES FROM SATURDAY NIGHT
ONWARD ARE EXPECTED TO DROP INTO THE SINGLE DIGITS ABOVE ZERO
ACROSS MUCH OF THE CWA.
WITH THE PRIMARY 3 WEATHER "REGIMES" AND THEIR CONCERNS BROKEN
DOWN ABOVE...WILL FINISH WITH A FAIRLY BRIEF LOOK AT A BIT MORE
METEOROLOGICAL DETAIL IN 12-60 HOUR BLOCKS:
TUESDAY EVENING/NIGHT: ALTHOUGH PREVIOUS FORECAST ALREADY
INTRODUCED THE POSSIBILITY OF SOME LIGHT FREEZING DRIZZLE IN FAR
SOUTHEAST COUNTIES...THIS LATEST PACKAGE HAS EXPANDED THIS "SLIGHT
CHANCE" MENTION OF FREEZING DRIZZLE AND/OR DRIZZLE TO ENCOMPASS
THE MAJORITY OF THE CWA...ASSUMING OF COURSE THAT WIDESPREAD LOW
STRATUS CLOUDS DO IN FACT DOMINATE THE AREA IN INCREASINGLY-MOIST
LOW LEVEL SOUTHERLY FLOW. VARIOUS 12Z/18Z MODELS ARE IN GOOD
AGREEMENT IN TRACKING THE FIRST LEGITIMATE-BUT-LOW-AMPLITUDE MID
LEVEL SHORTWAVE TROUGH OF THE WEEK NORTHEASTWARD ACROSS THE HEART
OF NEB/KS...THUS PROVIDING AT LEAST LOW-LEVEL LIFT FOR SOME
DRIZZLY ACTIVITY. THERE ARE HINTS THAT MAINLY THE FAR SOUTHEAST
CWA COULD SEE A QUICK BURST OF SNOW/POSSIBLY SLEET...BUT THIS
SEEMS MORE FAVORED OUTSIDE THE CWA WITHIN EASTERN KS. ASSUMING
PLENTIFUL CLOUDS AND SOUTHERLY SURFACE BREEZES GENERALLY 10-15
MPH...THIS SHOULD BE A SEASONABLY "MILD" NIGHT WITH LOWS ONLY
DROPPING TO AROUND 30 MOST PLACES.
WEDNESDAY/WEDNESDAY NIGHT: WHILE THE LOCAL AREA LARGELY SITS "IN
BETWEEN" UPPER LEVEL WAVES/FORCING DURING THIS TIME...THE PESKY
LOW-LEVEL STRATUS/SATURATION LOOKS TO PERSIST...AND THUS HAVE KEPT
A MENTION OF LIGHT RAIN/FREEZING RAIN OR LIGHT DRIZZLE/FREEZING
DRIZZLE GOING MUCH OF THIS TIME...DEPENDING ON SURFACE TEMPS.
SPEAKING OF WHICH...CONFIDENCE IS BELOW AVERAGE REGARDING WED HIGH
TEMPS DEPENDING ON THE BATTLE OF SOUTHERLY WARM AIR ADVECTION
VERSUS CLOUD COVER...BUT IF ANYTHING NUDGED HIGHS DOWN 1-2 DEGREES
FROM PREVIOUS WITH MID-UPPER 30S IN MOST NEB ZONES.
THURSDAY-THURSDAY NIGHT: SEE NUMBER "2" ABOVE FOR VARIOUS COMMENTS
ON THIS POSSIBLE SNOW EVENT...BUT IT WOULD GET UNDERWAY DURING
THIS TIME FRAME AS THE NEXT BATCH OF MID-UPPER FORCING ARRIVES
FROM THE SOUTHWEST...ALTHOUGH NOT IN AN OVERLY-ORGANIZED FASHION.
LATER FORECASTS MAY HAVE TO CONSIDER EXTENDING DRIZZLE/FREEZING
DRIZZLE POTENTIAL INTO AT LEAST THURSDAY DAYTIME BEFORE STEADIER
SNOW AND/OR RAIN BECOMES THE MORE DOMINANT TYPE. HAVE LOW END
"LIKELY" 60 PERCENT PRECIP CHANCES ACROSS MOST OF THE CWA FOR
THURSDAY NIGHT.
FRIDAY-FRIDAY NIGHT: ALTHOUGH ITS POSSIBLE THAT A LITTLE RAIN
POTENTIAL COULD STILL BE PRESENT BY SUNRISE FRIDAY IN FAR
SOUTHEAST ZONES...DEEPENING COLD AIR BEHIND A PASSING SURFACE COLD
FRONT SHOULD TRANSITION PRECIP TYPE TO SNOW ACROSS THE ENTIRE AREA
IF IT HASN`T ALREADY. WHILE SOME MODELS SUCH AS THE GFS PRETTY
MUCH SHUT DOWN ACCUMULATING SNOW BY FRIDAY NIGHT...OTHERS SUCH AS
THE ECMWF KEEP IT GOING.
SATURDAY DAYTIME-MONDAY DAYTIME: NOTHING MORE TO SAY HERE OTHER
THAN WHAT WAS ALREADY COVERED IN NUMBER "3" EARLIER ON: CONFIDENCE
IS REASONABLY HIGH IN A MAINLY SNOW-FREE STRETCH OF WEATHER WITH
THE ONLY REAL QUESTION SURROUNDING HOW COLD IT ACTUALLY GETS.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1118 PM CST MON JAN 4 2016
LOW CLOUDS HAVE ALREADY MOVED INTO THE TERMINALS AND EXPECT THE
IFR CEILINGS TO CONTINUE THROUGH THE NIGHT AND INTO THE MORNING
HOURS. VISIBILITIES WILL DROP TO MVFR LATER TONIGHT AND INTO THE
MORNING. CEILINGS WILL LIFT A LITTLE DURING THE DAY TIME...BUT
ARE EXPECTED TO DROP BACK AGAIN AFTER DARK.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...WESELY
LONG TERM...PFANNKUCH
AVIATION...JCB
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
844 PM CST WED JAN 6 2016
.UPDATE...
ADJUSTED RAIN CHANCES FOR THE REST OF TONIGHT...MAINLY TO LOWER
THEM OVER WESTERN OKLAHOMA AND WESTERN NORTH TEXAS AS WELL AS
INCREASE THEM EAST OF I-35.
&&
.DISCUSSION...
A COOL MOIST NIGHT WILL OCCUR WITH SOME RAIN SHOWERS AND FOG
DEVELOPING.
LATEST RADARS INDICATED LIGHT RAIN SHOWERS MAINLY FROM NEAR
WATONGA TO KINGFISHER TO PERRY PUSHING NORTHEAST WITH ANOTHER
BAND MOVING INTO THE MARIETTA...TISHOMINGO...AND ARDMORE AREAS.
ADJUSTED RAIN CHANCES TO ACCOUNT FOR THESE BANDS AND LATEST HRRR
COMPOSITE RADAR FORECASTS OVER THE NEXT SEVERAL HOURS. APPEARS
MOST OF THE RAIN WILL END BY MIDNIGHT ACROSS THE AREA.
KEPT FOG MENTION ACROSS THE ENTIRE AREA AFTER MIDNIGHT TONIGHT
THROUGH THURSDAY MORNING. THERE IS SOME POTENTIAL FOR DENSE
FOG...PARTICULARLY IN WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS...BUT NOT SURE IT WILL OCCUR. THUS...HELD OFF WITH ISSUING
A DENSE FOG ADVISORY. SOME DRIER AIR AND LOW LEVEL WINDS VEERING
TO THE SOUTHWEST WOULD NOT FAVOR WIDESPREAD DENSE FOG FORMATION.
HOWEVER...IT IS CONCERNING THAT THE LATEST ELK CITY AND CHILDRESS
OBSERVATIONS DEPICTED 1/4 MILE SURFACE VISIBILITY. WILL CLOSELY
MONITOR.
PRODUCTS WILL BE UPDATED SHORTLY.
MBS
&&
.PREV DISCUSSION... /ISSUED 557 PM CST WED JAN 6 2016/
UPDATE...
INCREASED RAIN CHANCES THIS EVENING ACROSS CENTRAL AND NORTHERN
OKLAHOMA. ALSO...ADDED FOG MENTION AFTER MIDNIGHT TONIGHT INTO
THURSDAY MORNING ACROSS MUCH OF THE AREA.
DISCUSSION...
A COOL AND RAINY NIGHT IS IN STORE TONIGHT.
LATEST RADARS INDICATED ISOLATED TO NUMEROUS ECHOES ACROSS THE
WESTERN HALF OF OKLAHOMA AND PARTS OF NORTH TEXAS. ALL OF THIS
ACTIVITY IS IN THE FORM OF LIGHT TO MODERATE RAIN AT THE GROUND.
THIS ACTIVITY WILL CONTINUE TO PUSH NORTHEAST THIS EVENING. RAIN
CHANCES WILL GENERALLY DECREASE AFTER MIDNIGHT SOUTHWEST TO
NORTHEAST. CHANCES FOR THUNDER SEEM TO BE TOO LOW TO MENTION.
FOG MAY BECOME WIDESPREAD AND DENSE LATE TONIGHT INTO THURSDAY
MORNING DUE TO ABUNDANT LOW LEVEL MOISTURE. THERE IS A SIGNAL THAT
THE DENSEST FOG MAY BE OVER WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS...ESPECIALLY IF LOW CLOUD COVER CAN CLEAR AS DEPICTED BY THE
LATEST HRRR RUNS. NOT SURE HOW DENSE FOG WILL GET AS LOW LEVEL
WINDS MAY STAY JUST STRONG ENOUGH TO KEEP VISIBILITIES ABOVE 1/4
MILE...BUT WILL CLOSELY MONITOR.
TEMPERATURES WILL NOT MOVE MUCH AT ALL TONIGHT.
PRODUCTS HAVE BEEN UPDATED.
MBS
PREV DISCUSSION... /ISSUED 548 PM CST WED JAN 6 2016/
AVIATION...
PRECIPITATION CONTINUES TO MOVE NORTHEAST AND WILL AFFECT MAINLY
CENTRAL AND SOUTHWEST OKLAHOMA TAF SITES THIS EVENING. CEILINGS
ARE EXPECTED TO LOWER MORE THROUGH THE EVENING WITH WIDESPREAD IFR
CEILINGS EXPECTED OVERNIGHT. SURFACE WINDS WILL VEER THURSDAY
PUSHING LOW-LEVEL MOISTURE EAST AND HELPING CEILINGS TO RISE
AND/OR DISSIPATE... ALTHOUGH IT COULD BE LATE IN THE DAY BEFORE
CONDITIONS IMPROVE TO VFR AT THE CENTRAL AND NORTH CENTRAL
OKLAHOMA AIRPORTS.
PREV DISCUSSION... /ISSUED 352 PM CST WED JAN 6 2016/
DISCUSSION...
WE`LL HAVE AN ACTIVE WEATHER PATTERN THROUGH EARLY NEXT WEEK AS A
SERIES OF SHORTWAVES MOVE ACROSS OUR AREA. WARMER SOUTHERLY AIR
WILL REMAIN ASSOCIATED WITH THE FIRST OF TWO DISTURBANCES IN THE
SHORT RANGE, WITH COLDER AIR INTRUDING FOR THE START OF THE
WEEKEND.
A SHORT WAVE TROUGH CURRENTLY DIGGING ACROSS THE SOUTHWESTERN U.S.
WILL KEEP US OVERCAST THROUGH TONIGHT. ASCENT AHEAD OF THIS SYSTEM
WILL RESULT IN PERIODS OF -RA, WHICH HAS ALREADY DEVELOPED ACROSS
SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS. INCREASING MOISTURE
ACROSS OUR SOUTHWEST MAY RESULT IN SOME WIDESPREAD ADVECTION FOG
DEVELOPING THERE. MARGINALLY UNSTABLE AIR ACROSS SOUTHEAST
OKLAHOMA COULD PRODUCE A FEW WEAK THUNDERSTORMS IN THAT AREA.
EXPECTING THIS SYSTEM TO BE OUT BY THURSDAY AFTERNOON AS SKIES
WILL BEGIN CLEARING.
FOR LATE FRIDAY NIGHT, A TRAILING SECOND UPPER WAVE WILL BE
MOVING THROUGH, WHICH WILL BE PUSHING A COLD FRONT THROUGH FOR
SATURDAY. THE LATEST 1000-850 MB LAYER THICKNESS PROGS HAVE BEEN
CONSISTENT WITH COLD CANADIAN AIR BEHIND THE BOUNDARY. WARM
ADVECTION ASCENT AHEAD OF THE COLD FRONT WILL INCREASE RAIN POPS
FRIDAY NIGHT ACROSS NORTHWEST OKLAHOMA, AND BECOMING MORE
WIDESPREAD THROUGH THE NIGHT FROM WEST TO EAST ACROSS OUR AREA. AS
COLDER AIR MOVE IN BEHIND THE COLD FRONT, WE COULD SEE THE
PRECIPITATION CHANGE INTO A RAIN/SNOW MIX GENERALLY ALONG AND
NORTH OF I-44, WITH A CHANGEOVER TO -SN ACROSS WESTERN AND
NORTHERN OKLAHOMA AS THE SYSTEM EXITS OFF TO THE EAST. FOR NOW,
ANY SNOW ACCUMULATIONS WOULD BE LIGHT. HOWEVER, POPS WILL REMAIN
LOW IN THE 30-40 PERCENT RANGE FOR THIS SECOND SYSTEM, AS
ADEQUATE MOISTURE AVAILABLE IS STILL IN QUESTION.
SUNDAY WILL BE DRY AND COLD, WITH TEMPS STAYING BELOW FREEZING ALL
DAY ACROSS THE NORTHERN TWO THIRDS OF OUR AREA. A THIRD UPPER WAVE
WILL BE DIGGING ACROSS OUR AREA SUNDAY NIGHT INTO EARLY MONDAY
MORNING. IF ANY PRECIPITATION COULD DEVELOP WITH THIS SYSTEM, IT
WOULD BE IN THE FORM OF SNOW. HOWEVER, BOTH MEDIUM RANGE MODELS IN
DISAGREEMENT WITH A SOLUTION, WITH GFS BRINGING IN WIDESPREAD QPF,
AND THE ECMWF KEEPING IT CONTAINED SOUTH OF THE RED RIVER. FOR
NOW, HAVE INTRODUCED LIGHT SNOW POPS ACROSS SOUTHERN OKLAHOMA AND
WESTERN NORTH TEXAS FOR EARLY MONDAY MORNING. A WARMING TREND AND
DRY CONDITIONS WILL BE IN STORE FOR TUESDAY INTO DAY 7.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 40 56 36 54 / 40 20 0 10
HOBART OK 43 55 34 53 / 50 10 0 0
WICHITA FALLS TX 44 63 37 60 / 30 0 0 0
GAGE OK 42 50 30 44 / 30 20 10 20
PONCA CITY OK 41 51 35 49 / 100 40 30 10
DURANT OK 40 61 42 63 / 100 10 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/26
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
557 PM CST WED JAN 6 2016
.UPDATE...
INCREASED RAIN CHANCES THIS EVENING ACROSS CENTRAL AND NORTHERN
OKLAHOMA. ALSO...ADDED FOG MENTION AFTER MIDNIGHT TONIGHT INTO
THURSDAY MORNING ACROSS MUCH OF THE AREA.
&&
.DISCUSSION...
A COOL AND RAINY NIGHT IS IN STORE TONIGHT.
LATEST RADARS INDICATED ISOLATED TO NUMEROUS ECHOES ACROSS THE
WESTERN HALF OF OKLAHOMA AND PARTS OF NORTH TEXAS. ALL OF THIS
ACTIVITY IS IN THE FORM OF LIGHT TO MODERATE RAIN AT THE GROUND.
THIS ACTIVITY WILL CONTINUE TO PUSH NORTHEAST THIS EVENING. RAIN
CHANCES WILL GENERALLY DECREASE AFTER MIDNIGHT SOUTHWEST TO
NORTHEAST. CHANCES FOR THUNDER SEEM TO BE TOO LOW TO MENTION.
FOG MAY BECOME WIDESPREAD AND DENSE LATE TONIGHT INTO THURSDAY
MORNING DUE TO ABUNDANT LOW LEVEL MOISTURE. THERE IS A SIGNAL THAT
THE DENSEST FOG MAY BE OVER WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS...ESPECIALLY IF LOW CLOUD COVER CAN CLEAR AS DEPICTED BY THE
LATEST HRRR RUNS. NOT SURE HOW DENSE FOG WILL GET AS LOW LEVEL
WINDS MAY STAY JUST STRONG ENOUGH TO KEEP VISIBILITIES ABOVE 1/4
MILE...BUT WILL CLOSELY MONITOR.
TEMPERATURES WILL NOT MOVE MUCH AT ALL TONIGHT.
PRODUCTS HAVE BEEN UPDATED.
MBS
&&
.PREV DISCUSSION... /ISSUED 548 PM CST WED JAN 6 2016/
AVIATION...
PRECIPITATION CONTINUES TO MOVE NORTHEAST AND WILL AFFECT MAINLY
CENTRAL AND SOUTHWEST OKLAHOMA TAF SITES THIS EVENING. CEILINGS
ARE EXPECTED TO LOWER MORE THROUGH THE EVENING WITH WIDESPREAD IFR
CEILINGS EXPECTED OVERNIGHT. SURFACE WINDS WILL VEER THURSDAY
PUSHING LOW-LEVEL MOISTURE EAST AND HELPING CEILINGS TO RISE
AND/OR DISSIPATE... ALTHOUGH IT COULD BE LATE IN THE DAY BEFORE
CONDITIONS IMPROVE TO VFR AT THE CENTRAL AND NORTH CENTRAL
OKLAHOMA AIRPORTS.
PREV DISCUSSION... /ISSUED 352 PM CST WED JAN 6 2016/
DISCUSSION...
WE`LL HAVE AN ACTIVE WEATHER PATTERN THROUGH EARLY NEXT WEEK AS A
SERIES OF SHORTWAVES MOVE ACROSS OUR AREA. WARMER SOUTHERLY AIR
WILL REMAIN ASSOCIATED WITH THE FIRST OF TWO DISTURBANCES IN THE
SHORT RANGE, WITH COLDER AIR INTRUDING FOR THE START OF THE
WEEKEND.
A SHORT WAVE TROUGH CURRENTLY DIGGING ACROSS THE SOUTHWESTERN U.S.
WILL KEEP US OVERCAST THROUGH TONIGHT. ASCENT AHEAD OF THIS SYSTEM
WILL RESULT IN PERIODS OF -RA, WHICH HAS ALREADY DEVELOPED ACROSS
SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS. INCREASING MOISTURE
ACROSS OUR SOUTHWEST MAY RESULT IN SOME WIDESPREAD ADVECTION FOG
DEVELOPING THERE. MARGINALLY UNSTABLE AIR ACROSS SOUTHEAST
OKLAHOMA COULD PRODUCE A FEW WEAK THUNDERSTORMS IN THAT AREA.
EXPECTING THIS SYSTEM TO BE OUT BY THURSDAY AFTERNOON AS SKIES
WILL BEGIN CLEARING.
FOR LATE FRIDAY NIGHT, A TRAILING SECOND UPPER WAVE WILL BE
MOVING THROUGH, WHICH WILL BE PUSHING A COLD FRONT THROUGH FOR
SATURDAY. THE LATEST 1000-850 MB LAYER THICKNESS PROGS HAVE BEEN
CONSISTENT WITH COLD CANADIAN AIR BEHIND THE BOUNDARY. WARM
ADVECTION ASCENT AHEAD OF THE COLD FRONT WILL INCREASE RAIN POPS
FRIDAY NIGHT ACROSS NORTHWEST OKLAHOMA, AND BECOMING MORE
WIDESPREAD THROUGH THE NIGHT FROM WEST TO EAST ACROSS OUR AREA. AS
COLDER AIR MOVE IN BEHIND THE COLD FRONT, WE COULD SEE THE
PRECIPITATION CHANGE INTO A RAIN/SNOW MIX GENERALLY ALONG AND
NORTH OF I-44, WITH A CHANGEOVER TO -SN ACROSS WESTERN AND
NORTHERN OKLAHOMA AS THE SYSTEM EXITS OFF TO THE EAST. FOR NOW,
ANY SNOW ACCUMULATIONS WOULD BE LIGHT. HOWEVER, POPS WILL REMAIN
LOW IN THE 30-40 PERCENT RANGE FOR THIS SECOND SYSTEM, AS
ADEQUATE MOISTURE AVAILABLE IS STILL IN QUESTION.
SUNDAY WILL BE DRY AND COLD, WITH TEMPS STAYING BELOW FREEZING ALL
DAY ACROSS THE NORTHERN TWO THIRDS OF OUR AREA. A THIRD UPPER WAVE
WILL BE DIGGING ACROSS OUR AREA SUNDAY NIGHT INTO EARLY MONDAY
MORNING. IF ANY PRECIPITATION COULD DEVELOP WITH THIS SYSTEM, IT
WOULD BE IN THE FORM OF SNOW. HOWEVER, BOTH MEDIUM RANGE MODELS IN
DISAGREEMENT WITH A SOLUTION, WITH GFS BRINGING IN WIDESPREAD QPF,
AND THE ECMWF KEEPING IT CONTAINED SOUTH OF THE RED RIVER. FOR
NOW, HAVE INTRODUCED LIGHT SNOW POPS ACROSS SOUTHERN OKLAHOMA AND
WESTERN NORTH TEXAS FOR EARLY MONDAY MORNING. A WARMING TREND AND
DRY CONDITIONS WILL BE IN STORE FOR TUESDAY INTO DAY 7.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 40 56 36 54 / 100 30 0 10
HOBART OK 43 55 34 53 / 80 10 0 0
WICHITA FALLS TX 44 63 37 60 / 40 10 0 0
GAGE OK 42 50 30 44 / 30 30 10 20
PONCA CITY OK 39 51 35 49 / 80 60 30 10
DURANT OK 40 61 42 63 / 80 20 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/26
AREA FORECAST DISCUSSION
NWS PORTLAND OR
944 PM PST MON JAN 4 2016
.SYNOPSIS...AN UPPER LEVEL LOW PRESSURE SYSTEM OFF THE COAST WILL
CONTINUE TO SEND A SERIES OF WEAK DISTURBANCES N THROUGH WESTERN
OREGON AND WASHINGTON THROUGH TUE NIGHT. A CHILLY AIR MASS WILL
REMAIN IN PLACE...REINFORCED BY E WINDS BLOWING THROUGH THE GORGE.
THIS WILL KEEP A CHANCE OF RAIN IN THE FORECAST FOR THE NEXT COUPLE
OF DAYS...ALONG WITH THE POSSIBILITY OF SOME FREEZING RAIN ESPECIALLY
IN AND AROUND THE GORGE. THE LOW WILL HEAD TOWARDS NORTHERN CA LATER
IN THE WEEK...LEAVING THE REGION WITH DWINDLING CHANCES FOR RAIN BUT
WITH COOL TEMPERATURES CONTINUING.
&&
.EVENING UPDATE...LATEST NWS DOPPLER RADAR IMAGERY SHOWS SOME WEAK
ECHOES OVER SW WASHINGTON AND NW OREGON THIS EVENING AS MID LEVEL
MOISTURE CONTINUES TO STREAM IN AHEAD OF LOW PRES OFFSHORE TO OUR
SOUTHWEST. OCCASIONAL LIGHT PRECIPITATION IS EXPECTED TO REACH THE
GROUND OVER THE NEXT FEW HOURS. MEANWHILE A MORE ORGANIZED AREA OF
PRECIPITATION IS MOVING ONTO THE N CALIF AND S OREGON COAST AHEAD OF
THE MAIN UPPER LEVEL TROUGH AND OCCLUDED LOW LEVEL FRONTAL BOUNDARY.
THE LATEST RUNS OF THE HRRR MODEL INDICATE A BIT STEADIER
PRECIPITATION TO DEVELOP OVER THE SOUTHERN PORTIONS OF THE FCST AREA
AFTER MIDNIGHT...THEN LIFT NORTHWARD OVERNIGHT INTO TUE AM.
HOWEVER...QPF TOTALS STILL LOOK TO BE QUITE LIGHT. LOOKING AT THE
OBSERVED TEMPERATURE TRENDS OF THE PAST FEW HOURS...DECIDED TO ISSUE
A FREEZING RAIN ADVISORY FOR MOST OF THE INTERIOR LOWLANDS AND FOR
THE COAST RANGE AND CASCADE FOOTHILLS. THERE ARE NUMEROUS LOCATIONS
THAT ARE NOW HOVERING RIGHT AT FREEZING. DEW POINTS OVER MUCH OF THE
REGION SIT AROUND 30 TO 32 DEG AND THERE IS CONSIDERABLE MID LEVEL
CLOUD COVER OVER THE REGION...SO DO NOT THINK WE WILL SEE TEMPS COOL
MUCH MORE AT THIS POINT. WIDESPREAD ICE ACCUMULATIONS ARE NOT
EXPECTED...BUT IT APPEARS THAT THERE IS POTENTIAL FOR LOCALIZED SPOTS
TO SEE AN ADDITIONAL GLAZING OF ICE GOING INTO THE TUE AM COMMUTE.
THE BEST CHANCES FOR THIS TO OCCUR ARE AROUND THE GORGE WHERE THE
COLD EASTERLY FLOW CONTINUES TO POUR THROUGH...AND POTENTIALLY IN THE
HIGHER TERRAIN AROUND THE PORTLAND METRO AREA. TEMPERATURES LOOK TO
WARM ABOVE FREEZING BY LATER TOMORROW MORNING FOR MOST OF THE
REGION...CONFINING ANY ADDITIONAL FROZEN PRECIPITATION THREAT TO THE
GORGE AREA AND THE CASCADES. PYLE
.PREVIOUS SHORT TERM DISCUSSION UNCHANGED...
TEMPERATURES THROUGH MOST OF THE WILLAMETTE VALLEY HAD WARMED ABOVE
FREEZING EARLY MON AFTERNOON...ALTHOUGH MESOWEST PLOTS SHOWED A FEW
POCKETS OF SUB FREEZING TEMPS...INCLUDING THE S END OF THE VALLEY
WHERE FOG AND LOW CLOUDS REMAINED. COLDER AIR REMAINED IN THE GORGE
AND HOOD RIVER VALLEY. AN OFFSHORE FLOW CONTINUED THROUGH THE GORGE
WHERE THE PDX TO DLS SURFACE PRES GRADIENT WAS STILL CLOSE TO 7 MB. A
COUPLE OF WEAK SHORTWAVES WERE EXPECTED TO MOVE N OVERNIGHT BRINGING
RENEWED THREATS OF PRECIPITATION...AS THE MAIN UPPER TROUGH REMAINS
OFFSHORE BETWEEN 130W AND 140W. A SLIGHTLY BETTER THREAT FOR
PRECIPITATION COMES TUE AS A SOUTHERLY H8 FLOW INCREASES MOISTURE
TRANSPORT AND ANOTHER SHORT WAVE LIFTS N. PRECIPITATION ASSOCIATED
WITH THE SHORTWAVES TONIGHT IS GENERALLY EXPECTED TO BE LIGHT WITH
MAIN MOISTURE CONFINED TO MID AND UPPER LEVELS. IN GENERAL WILL BRING
POPS BACK TO LIKELY CATEGORY MOST AREAS TONIGHT...WITH THE GREATER
THREAT COMING WITH THE SECOND SHORTWAVE LATE TONIGHT. THE AREAL
EXTENT OF SUB FREEZING TEMPS LATER TONIGHT INTO TUE MORNING IS NOT
CLEAR. MOS GUIDANCE AND MODELS IN GENERAL APPEAR TOO QUICK TO WARM
AND KEEP WARM THE SURFACE TEMPS. WILL TEND TO THE COLDER SIDE OF
GUIDANCE SURFACE TEMPS TONIGHT INTO TUE...WHICH COUPLED WITH CURRENT
TEMPS SUGGESTS THE NEED TO INCLUDE SOME CHANCE FOR FREEZING RAIN
THROUGHOUT THE WILLAMETTE VALLEY AND INTO THE COAST RANGE FOOTHILLS
TONIGHT. MAIN THREAT HOWEVER WILL REMAIN IN AND NEAR THE WESTERN
GORGE. WILL HOLD OFF ON ANY WINTER WEATHER ADVISORIES AT THIS
POINT...BUT SUSPECT SOME MAY BE NEEDED LATER TONIGHT AS FREEZING RAIN
BECOMES MORE IMMINENT TO SOME LOCATIONS. IN THE CENTRAL GORGE AND
HOOD RIVER VALLEY COLD AIR MASS REMAINS SUFFICIENTLY DEEP TO MAKE THE
PRIMARY THREAT SNOW. POPS HOWEVER WILL BE KEPT IN CHANCE CATEGORY
THERE.
MODELS IN GENERAL DIGGING THE UPPER LOW SE...HEADED TOWARDS NORTHERN
CA LATE IN THE WEEK. WITH THE BULK OF THE ENERGY HEADED S OF THE
FORECAST AREA...THE FOCUS FOR PRECIPITATION WILL ALSO SHIFT FURTHER
S. WILL TAPER OFF THE CHANCES FOR RAIN IN THE BEGINNING WED...BUT
HOLD ON TO SLIGHT CHANCE POPS THROUGH THU IN THE S.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY...THE MODELS ARE BUILDING
ANOTHER UPPER RIDGE ALONG THE PACIFIC NORTHWEST COAST EARLY IN THE
PERIOD THAT APPEARS IT WILL HANG ON UNTIL EARLY NEXT WEEK. ANY
INITIAL SYSTEMS LOOK TO SPLIT AND GO SOUTH OF OUR FORECAST AREA. WE
WILL CONTINUE TO HAVE TO DEAL WITH OUR PERSISTENT OFFSHORE FLOW
THROUGH THE GORGE...KEEPING TEMPS ON THE COOL SIDE. THE MODELS...
ESPECIALLY THE ECMWF AND GEM...SHOW SOME POSSIBILITIES OF
PRECIPITATION EARLY NEXT WEEK...AND HAVE SOME LOW POPS IN THE
FORECAST FOR THIS. THE GORGE WILL LIKELY BE DEALING WITH WINTER
PRECIPITATION...AND POSSIBLY IN THE NORTH INTERIOR AS WELL. TOLLESON
&&
.AVIATION...A PAIR OF DISTURBANCES WILL MOVE NORTH ACROSS THE
FORECAST AREA TONIGHT...AND AGAIN LATE TUESDAY. THE MAIN CONCERN
FOR THE UPCOMING TAF PACKAGE WILL CONTINUE TO BE THE PRECIP TYPE
IN THE NORTHERN INTERIOR AND FOG/LOW STRATUS FURTHER SOUTH. IN THE
NORTH...TEMPS LOOK TO HOVER RIGHT AROUND FREEZING ALL NIGHT.
SUSPECT WE WILL SEE SOME -RA WITH THE INITIAL SURGE OF PRECIP
TONIGHT...WITH THINGS POSSIBLY SWITCHING OVER TO -FZRA AFTER 08Z.
THE SOUTH VALLEY HAS STRUGGLED TO GET RID OF ITS LOWER
CLOUDS...SO SUSPECT LOWER CIGS WILL PERSIST AT KEUG AND LIKELY
REDEVELOP NEAR KSLE OVERNIGHT. IN ADDITION...PRECIP FURTHER SOUTH
LOOKS TO REMAIN -RA.
CONDITIONS ACROSS THE FORECAST AREA GENERALLY VFR...WITH POCKETS
OF MVFR VSBY AND IFR/LIFR CIGS. EXPECT CONDITIONS TO DETERIORATE
TOWARDS AT LEAST MVFR TONIGHT BEHIND THE INITIAL SURGE OF
MOISTURE. CONDITIONS LOOK TO IMPROVE TOWARDS VFR TUESDAY
AFTERNOON...BUT WILL LIKELY LOWER LATE TUESDAY WITH THE SECOND
SYSTEM. THE EXCEPTION WILL BE KHIO...KSLE...AND KEUG WHICH LOOK
TO REMAIN IFR. THE GOOD NEWS FOR THE TAFS IS THAT TEMPS TUESDAY
NIGHT LOOK TO REMAIN ABOVE FREEZING SO -FZRA CONCERNS WILL BE
MINIMAL.
KPDX AND APPROACHES...EXPECT MOSTLY VFR CONDITIONS AND ABOVE
FREEZING TEMPS THROUGH AROUND 08Z. INITIAL SURGE OF MOISTURE
TONIGHT WILL LOWER CIGS TOWARDS MVFR...WITH PRECIP POSSIBLY
SWITCHING TO -FZRA. CONDITIONS LOOK TO IMPROVE TOWARDS VFR TUESDAY
AFTERNOON. WILL LIKELY SEE -RA AND LOWER CIGS DEVELOP LATE
TUESDAY. /64
&&
.MARINE...EAST TO SOUTHEAST WINDS OVER THE WATERS GENERALLY
AROUND 15 KT WITH OCCASIONAL GUSTS TO NEAR 20 KT. SOUTHEAST WINDS
WILL INCREASE TONIGHT AHEAD OF THE NEXT LOW PRES SYSTEM BRINGING
GUSTS TO 30 KT AFTER MIDNIGHT. AS THE LOW APPROACHES THE OUTER
WATERS TUESDAY WINDS LOOK TO INCREASE FURTHER...WITH GUSTS TO 40
KT LIKELY DEVELOPING TUESDAY AFTERNOON. HOWEVER...00Z MODEL RUNS
HAVE PUSHED BACK THE TIMING OF THE STRONGEST GUSTS A FEW HOURS
AND THERE REMAINS SOME UNCERTAINTY WITH THE STRENGTH AND TRACK OF
THE LOW. WILL KEEP THE SMALL CRAFT ADVISORY FOR WINDS AND THE GALE
WATCH AS IS TO ALLOW FUTURE MODEL RUNS TO COME IN.
SEAS CONTINUE TO HOVER AROUND 7 TO 9 FT THIS EVENING WITH A
COMBINATION OF WEST AND SOUTH SWELLS AND EAST WIND WAVES CREATING
CONFUSED SEAS. A SERIES OF STRONG STORM SYSTEMS SOUTH OF THE
ALEUTIANS WILL BUILD A LONG PERIOD SWELL THAT WILL ARRIVE LATE
TONIGHT. SEAS WILL BUILD TOWARDS 11 FT AFTER MIDNIGHT AND PEAK
NEAR 17 FT TUESDAY AFTERNOON SO WILL KEEP THE SMALL CRAFT ADVISORY
FOR SEAS AS IS. THERE IS ALSO A CHANCE THAT WE MAY SEE SOME HIGH
SURF CONDITIONS ON THE NW OREGON COAST TUESDAY...BUT CONFIDENCE IS
LOW AND CONDITIONS REMAIN MARGINAL SO WILL HOLD OFF ON ISSUING A
HIGH SURF ADVISORY. SEAS LIKELY REMAIN ELEVATED THROUGH THE END OF
THE WEEK. /64
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY MORNING FOR
WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10
TO 60 NM-WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO
60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM MIDNIGHT TONIGHT TO 10 AM
PST TUESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT
TO 10 AM PST TUESDAY FOR COASTAL WATERS FROM CAPE
SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 10 PM
THIS EVENING TO 2 AM PST TUESDAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 9 AM
TO 9 PM PST TUESDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
339 PM CST TUE JAN 5 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 336 PM CST TUE JAN 5 2016
THE HRRR MODEL WHICH I HAVE NOT BEEN ABLE TO SEE SINCE THE 12Z
RUN...AT LEAST HAD AN EXCELLENT HANDLE ON THE LOW CLOUDS OVER THE
AREA AT THAT TIME. THE STRATUS CONTINUES TO CLEAR STEADILY FROM THE
SOUTH/SOUTHEAST AND IS ACCOMPANIED BY A SLOWER EROSION ON THE
WESTERN SIDE. THIS WILL LEAVE ONLY A LITTLE WEDGE FROM ROUGHLY DE
SMET TO BROOKINGS LATE AFTERNOON AND THAT SHOULD CONTINUE TO CLEAR
AS THE DECENT LOW LEVEL FLOW CONTINUES.
OTHERWISE...TONIGHT WILL BRING HIGH AND THEN MIDDLE CLOUDS
INCREASING FROM THE SOUTH AS A WEAK UPPER WAVE APPROACHES FROM THE
SOUTHWEST. LOW CLOUDS SHOULD BE INCREASING AGAIN BY EARLY WEDNESDAY
MORNING BUT OF COURSE THE MORE IMPORTANT ISSUE WILL BE THE ARRIVAL
OF LIGHT PRECIPITATION WITH THIS WAVE. IT STILL LOOKS LIKE JUST A
SLIGHT CHANCE FAR SOUTH LATE TONIGHT...THOUGH OF COURSE THE
PRECIPITATION IS LIKELY TO BE INCREASING IN COVERAGE IN THE LAST
COUPLE OF HOURS BEFORE SUNRISE...WHICH FOR WEDNESDAY IS STILL AT OUR
LATEST 8 AM SHARP TIME FOR SIOUX FALLS. AREAS OF LIGHT
PRECIPITATION WILL SPREAD MOSTLY OVER NORTHWEST IOWA INTO THE
EASTERN PART OF SOUTHWEST MINNESOTA THROUGH EARLY AFTERNOON. WILL GO
WITH LIKELY POPS FAR EAST AND CHANCE/SLIGHT CHANCE BACK WEST INTO
SOUTHEAST SOUTH DAKOTA...WITH GREATER COVERAGE LIKELY JUST EAST OF
THE AREA. AMOUNTS THROUGH WEDNESDAY SHOULD BE BELOW A TENTH OF AN
INCH.
A FAIRLY LOW AND SHALLOW WARM LAYER WILL MEAN THE START OF
PRECIPITATION MAY BE A MIXTURE OF SLEET SNOW AND FREEZING RAIN/RAIN.
THIS WARM LAYER SHOULD COOL AS THE DAY PASSES AND WITH THE DURATION
OF ANY PRECIPITATION SO EXPECT PRETTY MUCH ALL SNOW FOR THE
AFTERNOON. IN LINE WITH THE LIGHT PRECIPITATION NATURE...ANY SNOW
ACCUMULATIONS THROUGH WEDNESDAY SHOULD BE LESS THAN AN INCH.
THROUGH ALL THIS...TEMPERATURES WILL NOT SHOW MUCH DROP TONIGHT WITH
PERIODS OF STEADY TEMPERATURES OR EVEN SLIGHT WARMING POSSIBLE.
WEDNESDAY LIKEWISE WILL NOT SHOW MUCH WARMING WITH HIGHS AT MOST A
DEGREE OR TWO ABOVE FREEZING. WINDS WILL KEEP THEIR SOUTHERLY
NATURE BUT DECREASE SLOWLY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 PM CST TUE JAN 5 2016
ACTIVE WEATHER IN THE MID RANGE WILL BE FOLLOWED BY MUCH COLDER AND
DRY WEATHER BEGINNING THIS WEEKEND.
SHORTWAVE LIFTING NORTHEAST THROUGH THE REGION ON WEDNESDAY WILL
EXIT THE AREA WEDNESDAY NIGHT. WHILE MEASURABLE PRECIPITATION
CHANCES FALL OFF QUICKLY IN THE EVENING AS THE WAVE PULLS AWAY...LOW
STRATUS WILL LINGER OVERNIGHT. WITH THETA E ADVECTION AND PLENTY OF
LOW LEVEL MOISTURE...EXPECT THAT SOME DRIZZLE OR FREEZING DRIZZLE
WILL SPREAD ACROSS THE REGION LATE WEDNESDAY NIGHT INTO THURSDAY.
TEMPERATURES REMAIN MILD...WITH HIGHS WITHIN A FEW DEGREES ABOVE AND
BELOW FREEZING.
THE NEXT SHORTWAVE LIFTS NORTH NORTHEAST FROM THE CENTRAL PLAINS
THURSDAY EVENING...REACHING THE WESTERN GREAT LAKES ON FRIDAY
AFTERNOON. LIGHT PRECIPITATION WILL SPREAD INTO NORTHWEST IOWA
THURSDAY AFTERNOON AND SPREAD ACROSS THE REST OF THE FORECAST AREA
THURSDAY NIGHT AND FRIDAY MORNING. PRECIPITATION CHANCES LOOK TO BE
HIGHEST IN OUR FAR EAST WITH THIS SYSTEM...TAPERING TO LOW END
CHANCES IN OUR WEST. WHILE PRECIPITATION AMOUNTS ARE NOT
PARTICULARLY HIGH...DID BOOST POPS TO CATEGORICAL IN OUR FAR
SOUTHEAST. PRECIPITATION TYPE WILL PRIMARILY BE SNOWFALL...BUT WITH
HIGH TEMPERATURES NEAR OR JUST ABOVE FREEZING IN OUR EAST WHERE THE
HIGHEST AMOUNTS ARE EXPECTED. RAIN MAY MIX WITH SNOW AT TIMES...AND
WILL HELP KEEP SNOWFALL AMOUNTS FAIRLY LOW. PRELIMINARY
AMOUNTS...EXPECT AROUND 1 TO 3 INCHES OF SNOW IN THE EAST...WITH
LESS THAN AN INCH WEST OF I29.
BEHIND THIS SYSTEM...MUCH COLDER AIR FILTERS INTO THE REGION FROM
CANADA. DEEP TROUGH LINGERS OVER THE NORTHERN PLAINS THIS WEEKEND
INTO EARLY NEXT WEEK. BREEZY NORTHERLY WINDS ON FRIDAY AND SATURDAY
WILL ALLOW TEMPERATURES TO FALL FRIDAY AFTERNOON AND
OVERNIGHT...REMAINING STEADY OR SLOWLY FALLING DURING THE DAY
SATURDAY. LOWS SATURDAY NIGHT AND SUNDAY NIGHT WILL DROP BELOW ZERO
AREAWIDE...WITHOUT MUCH IMPROVEMENT DURING THE DAY ON SUNDAY. RIGHT
NOW IT LOOKS LIKE AT LEAST OUR NORTHERN HALF WILL SEE ADVISORY LEVEL
WIND CHILLS SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1130 AM CST TUE JAN 5 2016
CEILINGS NEAR 1K FEET OVER THE CENTRAL AND NORTHEAST PARTS OF THE
AREA WILL DECREASE FROM THE SOUTH AND WEST THROUGH 06/00Z...LEAVING
THE AREA WITH VFR AT THAT TIME. VFR CONDITIONS ARE EXPECTED 06
/00Z-09Z. 06/09Z-18Z CEILINGS 1-2K FEET WILL INCREASE FROM THE
SOUTH AND WEST OVER THE AREA. AREAS OF VISIBILITIES 3-5SM/-IPSN
WILL DEVELOP OVER NORTHWEST IA AND EXTREME SOUTHEAST SD AFTER
06/12Z...SPREADING INTO SOUTHWEST MN BY 06/18Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CST WED JAN 6 2016
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 301 PM CST WED JAN 6 2016
MESSY WINTER WEATHER TO IMPACT THE AREA THROUGH THE PERIOD.
WATER VAPOR IMAGERY SHOWING A VIGOROUS MID-LEVEL TROUGH/CLOSED LOW
OVER WESTERN IA. RADAR MOSAIC SHOWING PRECIPITATION EXPANDING AHEAD
OF THIS WAVE FROM SOUTHERN MN INTO IA AND SOUTHERN WI. GROUND
OBSERVATIONS SHOWING MAINLY A MIXTURE OF DRIZZLE/SNOW ACROSS THAT
AREA.
WILL BE WATCHING THAT MID-LEVEL LOW LIFT NORTHEAST INTO/THROUGH THE
AREA TONIGHT WHILE WEAKENING/DAMPENING OUT. RAP SHOWS THAT THE P-
TYPE SHOULD BE MAINLY IN THE FORM OF LIGHT SNOW WITH INCREASING
COLUMN SATURAION WITH ICE PRESENT IN CLOUD. HOWEVER...THINGS COULD
GET TRICKY FROM AROUND MIDNIGHT THROUGH THE OVERNIGHT HOURS AS THE
WAVE LIFTS NORTHEAST OF THE AREA WITH LOSS OF ICE IN CLOUD AND SOME
LINGERING LIFT THROUGH THIS CLOUD. IF THERE IS INDEED TOTAL ICE
LOSS...COULD BE A BOUT OF FREEZING DRIZZLE. THIS LOOKS MOST LIKELY
FOR AREAS ALONG AND WEST OF THE MISSISSIPPI RIVER. OTHERWISE...COULD
SEE UP TO AN INCH OF SNOWFALL OVERNIGHT. WILL ALSO SEE SOME FOG
MAINLY ALONG/SOUTH OF I-90 WITH WARMING/INCREASING MOISTURE THROUGH
TONIGHT. THIS FOR THE MOST PART LOOKS LIKE A SUB-HEADLINE
EVENT...BUT WILL KEEP A CLOSE EYE ON THE WEATHER AS IT EVOLVES.
FOR THURSDAY...MODELS SHOW MID-LEVEL RIDGING BUILDING BEHIND THE
DEPARTING WAVE THURSDAY MORNING...BUT WILL HAVE PLENTY OF LINGERING
MOISTURE/STRATUS FOR SOME PATCHY DRIZZLE AS WEAK LIFT CONTINUES
THROUGH THE SUPER-COOLED/ICE-LESS CLOUD LAYER. COULD SEE SOME PATCHY
FREEZING DRIZZLE AS WELL FOR AREAS THAT REMAIN BELOW 32 IN THE
MORNING. HOWEVER...ROADS SHOULD BE TREATED ENOUGH FOR MINIMAL TRAVEL
IMPACT. MOISTURE/PRECIPITATION CHANCES RAMP UP IN THE AFTERNOON
AHEAD OF A STRONGER WAVE MOVING OUT OF THE SOUTHERN PLAINS. WITH
HIGH TEMPERATURES PUSHING WELL INTO THE 30S...LOOKS LIKE A RAIN/SNOW
MIX SETTING UP. AS SUCH...NOT EXPECTING ANY APPRECIABLE SNOW
ACCUMULATIONS...PERHAPS A DUSTING/TENTH OF AN INCH IN SOME HIGHER
TERRAIN AREAS. IN ADDITION...LOOKS LIKE FOG WILL BE INCREASING AS
WELL AS THIS WARMING/MOIST AIR RIDES OVER THE EXISTING COLD SNOW
PACK. WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR DENSE FOG.
FOR THURSDAY NIGHT...MOISTURE WILL CONTINUE TO SPILL INTO THE AREA
AHEAD OF LOW PRESSURE MOVING INTO NORTHERN MO BY EARLY FRIDAY
MORNING. MODEL SOUNDING TEMPERATURE PROFILES SUPPORT A RAIN/SNOW MIX
ACROSS THE AREA WITH HIGHER TERRAIN FAVORING MORE SNOW THAN RAIN.
COULD SEE 1-2 INCHES ACROSS HIGHER TERRAIN AREAS MAINLY FROM
SOUTHEAST MN INTO NORTH CENTRAL WI.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 301 PM CST WED JAN 6 2016
FRIDAY WILL SEE THE LOW MOVE THROUGH EASTERN WI. LATEST
MODELS/THINKING IS THAT MAINLY RAIN WILL BE SEEN ACROSS MOST OF THE
AREA THROUGH THE DAY WITH RAIN/SNOW MIX FROM NORTHEAST IA/SOUTHEAST
MN INTO NORTH CENTRAL WI AS COLDER AIR FILTERS IN ON THE BACKSIDE OF
THE LOW. COULD SEE UP TO AN INCH OF ADDITIONAL SNOWFALL ACROSS THAT
AREA. OTHERWISE...LOOK FOR HIGH TEMPERATURES ACROSS THE AREA IN THE
MID TO UPPER 30S.
COLDER AIR FILTERS INTO THE AREA FRIDAY NIGHT INTO SATURDAY ALONG
WITH A CHANCE FOR LIGHT SNOW. LOOK FOR LOWS FRIDAY NIGHT MAINLY IN
THE 20S WITH HIGHS ON SATURDAY NOT BUDGING MUCH FROM THE OVERNIGHT
LOWS.
SMALL CHANCE OF SNOW LINGERS INTO SATURDAY NIGHT AS COLDER ARCTIC
AIR SPILLS INTO THE REGION. BY EARLY SUNDAY MORNING...WE WILL BE
LOOKING AT TEMPERATURE ONLY IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO ALONG WITH A FAIRLY STILL WIND IN THE 10 TO 20 MPH RANGE WITH A
FEW GUSTS AROU7ND 25 MPH. THIS WILL PRODUCE WIND CHILLS SUNDAY
MORNING IN THE MINUS 15 TO MINUS 25 DEGREE RANGE ACROSS SOUTHEAST
MN/NORTHEAST IA. WILL HAVE TO KEEP AN EYE ON THIS FOR POTENTIAL
WINDCHILL HEADLINES ACROSS THAT AREA.
MAIN STORY FOR SUNDAY THROUGH WEDNESDAY WILL BE ARCTIC AIRMASS
PAYING US A VISIT. HIGHS START OFF IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO SUNDAY...MODERATING SOME INTO THE SINGLE DIGITS/TEENS
ABOVE ZERO MONDAY THROUGH WEDNESDAY. OVERNIGHT LOWS LOOK TO BE IN
THE SINGLE DIGITS ABOVE/BELOW ZERO.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 610 PM CST WED JAN 6 2016
LIGHT SNOW WILL OVERSPREAD THE TAF SITES THIS EVENING WITH
PERIODS OF IFR CONDITIONS EXPECTED. THE SNOW WILL TAPER OFF AFTER
MIDNIGHT AND SWITCH OVER TO A VERY LIGHT DRIZZLE/FREEZING DRIZZLE.
THE LOWER CEILINGS AND VISIBILITIES WILL NOT IMPROVE OVERNIGHT
THROUGH THURSDAY WITH LOW STRATUS AND FOG EXPECTED. PLAN ON IFR TO
LIFR CONDITIONS AT TIMES...WITH VLIFR CONDITIONS POSSIBLE IN FOG
AT KRST. A MIX OF RAIN AND SNOW THURSDAY AFTERNOON SHOULD THEN
SWITCH OVER TO SNOW THURSDAY NIGHT WITH ACCUMULATIONS OF 1 TO 3
INCHES POSSIBLE. LOOK FOR THE IFR TO LIFR CONDITIONS TO PERSIST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1128 AM CST TUE JAN 5 2016
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 426 AM CST TUE JAN 5 2016
MORE ACTIVE STRETCH BEGINS WEDNESDAY AFTERNOON...CONTINUING INTO
THE WEEKEND. SPENT MOST WORK TRYING TO PIN DOWN PRECIPITATION
TYPES...TIMING...AND CHANCES FOR THE LIGHTER PRECIPITATION
WED/THU...AND WEATHER SYSTEM ON THURSDAY NIGHT AND FRIDAY.
GOES WATER VAPOR IMAGERY SHOWING A NICE SHORTWAVE TROUGH MOVING
TOWARD KMSP WITH MAIN INFLUENCE IN THE 500MB AND ABOVE LAYER PER
RAP TROPOPAUSE FOLD DEPTH TO 400 MB. AIR MASS ALOFT IS QUITE DRY
AND DO NOT EXPECT WEATHER FROM IT. MORE IMPRESSIVE SHORTWAVE
TROUGH OVER SWRN NEW MEXICO AT 09Z CLEARLY VISIBLE AND LIFTING
NORTHEAST...THIS WILL BRING PRECIPITATION IN FOR
WEDNESDAY AFTERNOON-NIGHT...AND NEXT TROUGH APPROACHING SRN CA IS
LATE THU-FRI WEATHER.
LOW CLOUDS IN FOG PRODUCT HAVE BEEN PRETTY BEHAVED TONIGHT SLIDING
NORTH IN THE STRONGER LOW-LEVEL SOUTHERLY FLOW. HOWEVER...THE
SOUTHERN PORTION IS ANCHORED NEAR KDSM AND I-80...SO THIS ISNT ALL
THAT EASY. BOTTOM LINE IS KEPT WI MOSTLY SUNNY WITH MN/IA SLOWLY
SEEING MORE SUNSHINE AS DAY PROGRESSES. GSD HRRR MODEL RUN SEEMS
TO HAVE THE BEST IDEA ON NORTHWARD TRACK.
WEDNESDAY AFTERNOON AND OVERNIGHT...
CONSISTENT SIGNAL CONTINUES FOR THIS PERIOD WITH VERY WEAK
FRONTOGENESIS TO THE NORTHWEST OVER MN...SHORTWAVE TROUGH FROM
NEW MEXICO APPROACHING THE AREA WITH WEAK QVECTOR
CONVERGENCE...WEAK ISENTROPIC UPGLIDE /280-290K/...AND SOME
INCREASE IN MOISTURE /2-4 G/KG/ ON A PLUME FROM WRN IA INTO MN
WEDNESDAY AFTERNOON. THIS ALL EVOLVES EASTWARD WEDNESDAY NIGHT
HOWEVER...IT STILL APPEARS THE BEST LIFT IS NORTHWESTERN AREAS OF
THE FORECAST AREA. KEPT FORECAST ABOUT THE SAME BUT ADDED MORE
TIMING TO PRECIPITATION CHANCES. STILL LOOKING LIKE A 1 INCH
SNOW. THERE IS SOME SUGGESTION OF A BIT OF A WARM LAYER BEFORE
FULL SATURATION OCCURS WHICH COULD MIX IN A BIT OF SLEET FOR AN
HOUR OR SO.
THE SHORTWAVE TROUGH WILL SHIFT EAST THURSDAY AND TAKE WITH IT
THE DEEP SATURATION...AND THE FORECAST AREA WILL LOSE ICE CLOUD
FROM SW TO NE. THIS SIGNAL HAS BEEN IN THE MODEL GUIDANCE...ACROSS
THE MODELS...FOR DAYS NOW...AND HAVE DECIDED TO ADD THE
POSSIBILITY OF DZ/FZDZ TO THE FORECAST. THE SATURATED LIQUID LAYER
IS OVER 2KM DEEP WITH SOME RESIDUAL LIFT AS THE TROUGH MOVES
EAST...WITH ABOUT 2-3 UB/S OF LIFT IN THE LAYER. HAVE LOWERED THE
PRECIPITATION CHANCES THURSDAY...SO IT LOOKS LIKE A CHANCE OF
FZDZ IN THE MORNING...THEN DZ IN THE AFTERNOON AS TEMPERATURES
WARM. ONLY A SKIM OF ICING WOULD BE POSSIBLE IF ANYTHING
MATERIALIZES AT ALL.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 426 AM CST TUE JAN 5 2016
THURSDAY NIGHT THROUGH FRIDAY...
THE 05.06Z MODEL GUIDANCE HAS REALLY COME INTO BETTER AGREEMENT
ON THE STRONGER SHORTWAVE TROUGH OF THE WEEK AND THE ONSET OF
PRECIPITATION INTO THE SOUTH THURSDAY EVENING WITH WARM ADVECTION
BURST....AND THE DEFORMATION BAND ROTATING NORTHWEST FRIDAY IN
CONCERT WITH A LOW-LEVEL INVERTED TROUGH. IT APPEARS THERE ARE
TWO INDIVIDUAL WAVES THAT WILL AFFECT THE AREA SO THIS PERIOD IS A
BIT MORE COMPLEX. THE LOW-LEVEL CYCLONE /925-850MB/ APPEARS TO BE
MORE CONSOLIDATED...WHICH COULD LEAD TO A FAIRLY NICE DEFORMATION
REGION WITH THIS SYSTEM FRIDAY. WITH THE TRACK THROUGH NRN IL...IT
APPEARS ONLY CENTRAL/SWRN WI AND FAR NERN IA WILL HAVE
PRECIPITATION TYPE ISSUES...AND SNOW TO THE NORTHWEST. EARLY SNOW
AMOUNTS SNOW LOOK LIKE 1-3 INCHES...WITH SOME RAIN OR SLEET
FURTHER SOUTHEAST. WILL NEED TO KEEP OUR EYE ON THIS ONE AS IT HAS
SOME GOOD ATTRIBUTES FOR A BIT HIGHER IMPACT IF IT STRENGTHENS
MORE.
SATURDAY THROUGH MONDAY...
DEEP TROUGH MOVE IN FROM THE NORTHWEST WITH PROBABLY A LIGHT SNOW
BURST ON THE FRONT...AND STRONG COLD ADVECTION. SATURDAY WILL BE
THE LAST NEAR NORMAL DAY WITH GOOD AGREEMENT ON THE COLD WEEK
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY NOON)
ISSUED AT 1128 AM CST TUE JAN 5 2016
GOOD VFR CONDITIONS EXPECTED THIS PERIOD AS HIGH PRESSURE DRIFTS
EAST OF THE UPPER MIDWEST. MAIN CLOUDS THRU MID MORNING WED WILL BE
SCT-BKN NEAR/ABOVE 15K FT. BY LATER WED MORNING...SOME LOWER
MOISTURE AND MVFR CLOUDS...AHEAD OF THE NEXT SYSTEM COMING ACROSS
THE PLAINS...WILL START TO SPREAD EAST ACROSS THE AREA. BROUGHT A
SCT025 LAYER INTO KRST AFTER 14Z TO REFLECT THIS.
OTHERWISE...THE MAIN CONCERN FOR THIS AFTERNOON THRU 18Z WED WILL BE
STRONGER SOUTH WINDS AS THE TIGHTER PRESSURE GRADIENT ON THE BACK
SIDE OF THE RETREATING HIGH MOVES ACROSS THE AREA. SOUTH WINDS 15-
20KT G25-30KTS EXPECTED THIS AFTERNOON AND MUCH OF TONIGHT...
ESPECIALLY ACROSS THE HIGHER TERRAIN AREAS AND RIDGE-TOPS /KRST/.
WINDS IN THE MS/WI RIVER VALLEYS /KLSE/ NOT LOOKING TO MIX AS
MUCH...REMAINING MORE SOUTH 10-15KTS THRU THE PERIOD. WITH SOUTHWEST
WINDS AROUND 40KTS IN THE 1500-2000 FT AGL MUCH OF TONIGHT...DID ADD
LLWS TO KLSE TAF IN THE 00-09Z PERIOD. 925MB GRADIENT LOOKS TO RELAX
AFTER 09Z...WITH SOUTHWEST WINDS AROUND 2K FT MORE IN THE 30KT RANGE
BY 12-15Z WED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
526 AM CST TUE JAN 5 2016
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 426 AM CST TUE JAN 5 2016
MORE ACTIVE STRETCH BEGINS WEDNESDAY AFTERNOON...CONTINUING INTO
THE WEEKEND. SPENT MOST WORK TRYING TO PIN DOWN PRECIPITATION
TYPES...TIMING...AND CHANCES FOR THE LIGHTER PRECIPITATION
WED/THU...AND WEATHER SYSTEM ON THURSDAY NIGHT AND FRIDAY.
GOES WATER VAPOR IMAGERY SHOWING A NICE SHORTWAVE TROUGH MOVING
TOWARD KMSP WITH MAIN INFLUENCE IN THE 500MB AND ABOVE LAYER PER
RAP TROPOPAUSE FOLD DEPTH TO 400 MB. AIR MASS ALOFT IS QUITE DRY
AND DO NOT EXPECT WEATHER FROM IT. MORE IMPRESSIVE SHORTWAVE
TROUGH OVER SWRN NEW MEXICO AT 09Z CLEARLY VISIBLE AND LIFTING
NORTHEAST...THIS WILL BRING PRECIPITATION IN FOR
WEDNESDAY AFTERNOON-NIGHT...AND NEXT TROUGH APPROACHING SRN CA IS
LATE THU-FRI WEATHER.
LOW CLOUDS IN FOG PRODUCT HAVE BEEN PRETTY BEHAVED TONIGHT SLIDING
NORTH IN THE STRONGER LOW-LEVEL SOUTHERLY FLOW. HOWEVER...THE
SOUTHERN PORTION IS ANCHORED NEAR KDSM AND I-80...SO THIS ISNT ALL
THAT EASY. BOTTOM LINE IS KEPT WI MOSTLY SUNNY WITH MN/IA SLOWLY
SEEING MORE SUNSHINE AS DAY PROGRESSES. GSD HRRR MODEL RUN SEEMS
TO HAVE THE BEST IDEA ON NORTHWARD TRACK.
WEDNESDAY AFTERNOON AND OVERNIGHT...
CONSISTENT SIGNAL CONTINUES FOR THIS PERIOD WITH VERY WEAK
FRONTOGENESIS TO THE NORTHWEST OVER MN...SHORTWAVE TROUGH FROM
NEW MEXICO APPROACHING THE AREA WITH WEAK QVECTOR
CONVERGENCE...WEAK ISENTROPIC UPGLIDE /280-290K/...AND SOME
INCREASE IN MOISTURE /2-4 G/KG/ ON A PLUME FROM WRN IA INTO MN
WEDNESDAY AFTERNOON. THIS ALL EVOLVES EASTWARD WEDNESDAY NIGHT
HOWEVER...IT STILL APPEARS THE BEST LIFT IS NORTHWESTERN AREAS OF
THE FORECAST AREA. KEPT FORECAST ABOUT THE SAME BUT ADDED MORE
TIMING TO PRECIPITATION CHANCES. STILL LOOKING LIKE A 1 INCH
SNOW. THERE IS SOME SUGGESTION OF A BIT OF A WARM LAYER BEFORE
FULL SATURATION OCCURS WHICH COULD MIX IN A BIT OF SLEET FOR AN
HOUR OR SO.
THE SHORTWAVE TROUGH WILL SHIFT EAST THURSDAY AND TAKE WITH IT
THE DEEP SATURATION...AND THE FORECAST AREA WILL LOSE ICE CLOUD
FROM SW TO NE. THIS SIGNAL HAS BEEN IN THE MODEL GUIDANCE...ACROSS
THE MODELS...FOR DAYS NOW...AND HAVE DECIDED TO ADD THE
POSSIBILITY OF DZ/FZDZ TO THE FORECAST. THE SATURATED LIQUID LAYER
IS OVER 2KM DEEP WITH SOME RESIDUAL LIFT AS THE TROUGH MOVES
EAST...WITH ABOUT 2-3 UB/S OF LIFT IN THE LAYER. HAVE LOWERED THE
PRECIPITATION CHANCES THURSDAY...SO IT LOOKS LIKE A CHANCE OF
FZDZ IN THE MORNING...THEN DZ IN THE AFTERNOON AS TEMPERATURES
WARM. ONLY A SKIM OF ICING WOULD BE POSSIBLE IF ANYTHING
MATERIALIZES AT ALL.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 426 AM CST TUE JAN 5 2016
THURSDAY NIGHT THROUGH FRIDAY...
THE 05.06Z MODEL GUIDANCE HAS REALLY COME INTO BETTER AGREEMENT
ON THE STRONGER SHORTWAVE TROUGH OF THE WEEK AND THE ONSET OF
PRECIPITATION INTO THE SOUTH THURSDAY EVENING WITH WARM ADVECTION
BURST....AND THE DEFORMATION BAND ROTATING NORTHWEST FRIDAY IN
CONCERT WITH A LOW-LEVEL INVERTED TROUGH. IT APPEARS THERE ARE
TWO INDIVIDUAL WAVES THAT WILL AFFECT THE AREA SO THIS PERIOD IS A
BIT MORE COMPLEX. THE LOW-LEVEL CYCLONE /925-850MB/ APPEARS TO BE
MORE CONSOLIDATED...WHICH COULD LEAD TO A FAIRLY NICE DEFORMATION
REGION WITH THIS SYSTEM FRIDAY. WITH THE TRACK THROUGH NRN IL...IT
APPEARS ONLY CENTRAL/SWRN WI AND FAR NERN IA WILL HAVE
PRECIPITATION TYPE ISSUES...AND SNOW TO THE NORTHWEST. EARLY SNOW
AMOUNTS SNOW LOOK LIKE 1-3 INCHES...WITH SOME RAIN OR SLEET
FURTHER SOUTHEAST. WILL NEED TO KEEP OUR EYE ON THIS ONE AS IT HAS
SOME GOOD ATTRIBUTES FOR A BIT HIGHER IMPACT IF IT STRENGTHENS
MORE.
SATURDAY THROUGH MONDAY...
DEEP TROUGH MOVE IN FROM THE NORTHWEST WITH PROBABLY A LIGHT SNOW
BURST ON THE FRONT...AND STRONG COLD ADVECTION. SATURDAY WILL BE
THE LAST NEAR NORMAL DAY WITH GOOD AGREEMENT ON THE COLD WEEK
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 526 AM CST TUE JAN 5 2016
THE AREA OF PERSISTENT LOW CLOUDS OVER NORTHERN IOWA AND EASTERN
MINNESOTA HAS FINALLY BEGUN TO MOVE NORTH. THE CR-HRRR HAS BEEN
SHOWING THIS TREND FOR SEVERAL RUNS AND IT LOOKS LIKE AS THESE
LIFT NORTH...THEY WILL STAY TO THE WEST OF KLSE AND SHOULD MOVE
OUT OF KRST BETWEEN 13 AND 14Z. AFTER THAT...THE REST OF THE
PERIOD WILL HAVE VFR CONDITIONS WITH JUST SOME HIGH LEVEL CLOUDS
EXPECTED TO MOVE OVER. THERE WILL BE A PRETTY TIGHT GRADIENT IN
PLACE TO PRODUCE SOME GUSTY SOUTH WINDS AT KRST. PUSHED BACK THE
ONSET OF THE GUSTS A COUPLE OF HOURS FROM THE PREVIOUS FORECAST AS
IT SHOULD CLEAR JUST LONG ENOUGH TO HELP STRENGTHEN THE LOW LEVEL
INVERSION WITH SOME SURFACE COOLING JUST ENOUGH THAT THE GOOD LOW
LEVEL LAPSE RATES WILL BE DELAYED SOME. HOWEVER...ONCE THE GUSTS
GET GOING...THE FORECAST SOUNDINGS FROM THE 05.06Z NAM INDICATE
THE LOW LEVEL LAPSE RATES REMAIN IN PLACE TO KEEP SOME GUSTS GOING
OVERNIGHT AS WELL. FOR NOW...DID NOT INCLUDE ANY GUSTS AT KLSE AS
THE VALLEY MAY KEEP THE LOW LEVEL INVERSION IN PLACE AND NOT ALLOW
THE GOOD LOW LEVEL LAPSE RATES TO DEVELOP.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
428 AM CST TUE JAN 5 2016
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 426 AM CST TUE JAN 5 2016
MORE ACTIVE STRETCH BEGINS WEDNESDAY AFTERNOON...CONTINUING INTO
THE WEEKEND. SPENT MOST WORK TRYING TO PIN DOWN PRECIPITATION
TYPES...TIMING...AND CHANCES FOR THE LIGHTER PRECIPITATION
WED/THU...AND WEATHER SYSTEM ON THURSDAY NIGHT AND FRIDAY.
GOES WATER VAPOR IMAGERY SHOWING A NICE SHORTWAVE TROUGH MOVING
TOWARD KMSP WITH MAIN INFLUENCE IN THE 500MB AND ABOVE LAYER PER
RAP TROPOPAUSE FOLD DEPTH TO 400 MB. AIR MASS ALOFT IS QUITE DRY
AND DO NOT EXPECT WEATHER FROM IT. MORE IMPRESSIVE SHORTWAVE
TROUGH OVER SWRN NEW MEXICO AT 09Z CLEARLY VISIBLE AND LIFTING
NORTHEAST...THIS WILL BRING PRECIPITATION IN FOR
WEDNESDAY AFTERNOON-NIGHT...AND NEXT TROUGH APPROACHING SRN CA IS
LATE THU-FRI WEATHER.
LOW CLOUDS IN FOG PRODUCT HAVE BEEN PRETTY BEHAVED TONIGHT SLIDING
NORTH IN THE STRONGER LOW-LEVEL SOUTHERLY FLOW. HOWEVER...THE
SOUTHERN PORTION IS ANCHORED NEAR KDSM AND I-80...SO THIS ISNT ALL
THAT EASY. BOTTOM LINE IS KEPT WI MOSTLY SUNNY WITH MN/IA SLOWLY
SEEING MORE SUNSHINE AS DAY PROGRESSES. GSD HRRR MODEL RUN SEEMS
TO HAVE THE BEST IDEA ON NORTHWARD TRACK.
WEDNESDAY AFTERNOON AND OVERNIGHT...
CONSISTENT SIGNAL CONTINUES FOR THIS PERIOD WITH VERY WEAK
FRONTOGENESIS TO THE NORTHWEST OVER MN...SHORTWAVE TROUGH FROM
NEW MEXICO APPROACHING THE AREA WITH WEAK QVECTOR
CONVERGENCE...WEAK ISENTROPIC UPGLIDE /280-290K/...AND SOME
INCREASE IN MOISTURE /2-4 G/KG/ ON A PLUME FROM WRN IA INTO MN
WEDNESDAY AFTERNOON. THIS ALL EVOLVES EASTWARD WEDNESDAY NIGHT
HOWEVER...IT STILL APPEARS THE BEST LIFT IS NORTHWESTERN AREAS OF
THE FORECAST AREA. KEPT FORECAST ABOUT THE SAME BUT ADDED MORE
TIMING TO PRECIPITATION CHANCES. STILL LOOKING LIKE A 1 INCH
SNOW. THERE IS SOME SUGGESTION OF A BIT OF A WARM LAYER BEFORE
FULL SATURATION OCCURS WHICH COULD MIX IN A BIT OF SLEET FOR AN
HOUR OR SO.
THE SHORTWAVE TROUGH WILL SHIFT EAST THURSDAY AND TAKE WITH IT
THE DEEP SATURATION...AND THE FORECAST AREA WILL LOSE ICE CLOUD
FROM SW TO NE. THIS SIGNAL HAS BEEN IN THE MODEL GUIDANCE...ACROSS
THE MODELS...FOR DAYS NOW...AND HAVE DECIDED TO ADD THE
POSSIBILITY OF DZ/FZDZ TO THE FORECAST. THE SATURATED LIQUID LAYER
IS OVER 2KM DEEP WITH SOME RESIDUAL LIFT AS THE TROUGH MOVES
EAST...WITH ABOUT 2-3 UB/S OF LIFT IN THE LAYER. HAVE LOWERED THE
PRECIPITATION CHANCES THURSDAY...SO IT LOOKS LIKE A CHANCE OF
FZDZ IN THE MORNING...THEN DZ IN THE AFTERNOON AS TEMPERATURES
WARM. ONLY A SKIM OF ICING WOULD BE POSSIBLE IF ANYTHING
MATERIALIZES AT ALL.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 426 AM CST TUE JAN 5 2016
THURSDAY NIGHT THROUGH FRIDAY...
THE 05.06Z MODEL GUIDANCE HAS REALLY COME INTO BETTER AGREEMENT
ON THE STRONGER SHORTWAVE TROUGH OF THE WEEK AND THE ONSET OF
PRECIPITATION INTO THE SOUTH THURSDAY EVENING WITH WARM ADVECTION
BURST....AND THE DEFORMATION BAND ROTATING NORTHWEST FRIDAY IN
CONCERT WITH A LOW-LEVEL INVERTED TROUGH. IT APPEARS THERE ARE
TWO INDIVIDUAL WAVES THAT WILL AFFECT THE AREA SO THIS PERIOD IS A
BIT MORE COMPLEX. THE LOW-LEVEL CYCLONE /925-850MB/ APPEARS TO BE
MORE CONSOLIDATED...WHICH COULD LEAD TO A FAIRLY NICE DEFORMATION
REGION WITH THIS SYSTEM FRIDAY. WITH THE TRACK THROUGH NRN IL...IT
APPEARS ONLY CENTRAL/SWRN WI AND FAR NERN IA WILL HAVE
PRECIPITATION TYPE ISSUES...AND SNOW TO THE NORTHWEST. EARLY SNOW
AMOUNTS SNOW LOOK LIKE 1-3 INCHES...WITH SOME RAIN OR SLEET
FURTHER SOUTHEAST. WILL NEED TO KEEP OUR EYE ON THIS ONE AS IT HAS
SOME GOOD ATTRIBUTES FOR A BIT HIGHER IMPACT IF IT STRENGTHENS
MORE.
SATURDAY THROUGH MONDAY...
DEEP TROUGH MOVE IN FROM THE NORTHWEST WITH PROBABLY A LIGHT SNOW
BURST ON THE FRONT...AND STRONG COLD ADVECTION. SATURDAY WILL BE
THE LAST NEAR NORMAL DAY WITH GOOD AGREEMENT ON THE COLD WEEK
BEGINNING ON SUNDAY WITH SINGLE DIGIT HIGHS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1140 PM CST MON JAN 4 2016
05.0530Z IR SATELLITE SHOWS AN AREA OF IFR STRATUS FROM NORTH-
CENTRAL IA INTO EAST-CENTRAL MN...MOVING MORE NORTH THAN EAST
AROUND 10 MPH. WHILE KRST WILL REMAIN IFR THROUGH THE NIGHT...
LATEST FORECAST GUIDANCE SUGGESTS KLSE WILL LIKELY SKIRT THE
EASTERN EDGE OF THESE LOWER CLOUDS AND COULD GO EITHER WAY. WILL
TREND MORE VFR AT KLSE GIVEN INCREASING SOUTHERLY LOW-LEVEL FLOW
AND THE LATEST CLOUD MOVEMENT TRENDS...WITH ONLY A FOUR HOUR IFR
TEMPO GROUP FROM 05.08 TO 08.12Z. STRONG SOUTHERLY WINDS SHOULD
LIMIT FOG FORMATION WITH ONLY SOME MVFR RESTRICTIONS TO VISIBILITY.
IF LOW CLOUDS MOVE FAR ENOUGH NORTH AND DISSIPATE TUESDAY MORNING...
EXPECT A MOSTLY VFR DAY AT BOTH TAF AIRFIELDS. SOUTHERLY GUSTS AT
KRST UP TO 30 KTS POSSIBLE WITH LESSER WINDS AT KLSE THROUGH THE
PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
930 PM PST WED JAN 6 2016
.SYNOPSIS...
SHOWERS...LOCALLY HEAVY...WILL CONTINUE TONIGHT AND THURSDAY
MORNING...THEN BECOME GRADUALLY LESS NUMEROUS AND LESS INTENSE
THURSDAY AFTERNOON THROUGH FRIDAY. LOCAL FLASH FLOODING WILL BE
POSSIBLE THROUGH THURSDAY MORNING. HEAVY SNOW WILL OCCUR IN THE
MOUNTAINS AT TIMES THROUGH THURSDAY...MAINLY ABOVE 4500 FEET...THEN
GRADUALLY DECREASE THURSDAY NIGHT AND FRIDAY. VERY LARGE SURF WILL
OCCUR AT THE BEACHES THURSDAY...THEN START TO DECREASE FRIDAY. MORE
SHOWERS COULD OCCUR SATURDAY OR SATURDAY NIGHT...WITH FAIR WARMER
WEATHER LIKELY RETURNING FOR A COUPLE DAYS EARLY NEXT WEEK. ANOTHER
SYSTEM COULD BRING MORE PRECIPITATION AROUND THE MIDDLE OF NEXT
WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
SCATTERED SHOWERS CONTINUED IN MOST AREAS AT MID EVENING...WITH
LOCALLY BUT FAIRLY BRIEF HEAVY RAIN IN PARTS OF ORANGE COUNTY THE
PAST HOUR. THE TROUGH CURRENTLY OVER CALIFORNIA IS FAIRLY BROAD WITH
TRAINING VORT MAXES ON THE SOUTH SIDE...MOVING THROUGH SO-CAL
THROUGH EARLY THURSDAY AFTERNOON...FOR CONTINUOUS SHOWER ACTIVITY
WITH PERIODS OF MODERATE TO HEAVY RAIN...BUT ALSO PERIODS WITH
LIMITED PRECIPITATION. THE VORT MAX TRAIN WILL MOVE SOUTH INTO
NORTHERN BAJA THURSDAY AFTERNOON...SO THIS WILL HELP TO DECREASE THE
PRECIPITATION OVER SO-CAL GRADUALLY. AFTER THURSDAY...MOST OF THE
PRECIP WILL BE OVER SAN DIEGO COUNTY WITH JUST ISOLATED SHOWERS
FURTHER NORTH. WHILE WE SHOULD NOT REPEAT THE SIGNIFICANT FLOODING
EVENTS OF TUESDAY AND TODAY...WE STILL HAVE SOME THREAT OF LOCALIZED
FLASH FLOODING THROUGH THURSDAY MORNING...ESPECIALLY WHERE THE SOILS
ARE SATURATED AS ABOUT HALF OUR FORECAST AREAS HAS HAD RAINFALL
BETWEEN 2.5 AND 5 INCHES. SNOW LEVELS WILL FALL TO 4500 FEET
OVERNIGHT...SO ABOVE THAT LEVEL THE FLOOD THREAT WILL CHANGE (IF IT
HAS NOT ALREADY) TO THE SNOW THREAT...AND SOME AREAS HAVE ALREADY
HAD 2 FEET OF SNOW. 1 ADDITIONAL FOOT OF SNOW COULD FALL IN SOME
AREAS...ESPECIALLY OVER RIDGES AND UPPER WEST SLOPES...AND THE FOCUS
WILL GRADUALLY BECOME MORE ON THE SAN DIEGO COUNTY MOUNTAINS
THURSDAY VERSUS FURTHER NORTH.
SOME RIDGING COULD MOVE IN THIS WEEKEND THROUGH EARLY NEXT
WEEK...BUT THE EAST PACIFIC WILL CONTINUE TO HAVE MOIST FLOW...PLUS
THE NOW MOIST BOUNDARY LAYER OVER LAND...SO ANY IMPULSE THAT MOVES
THROUGH...SUCH AS ONE FOR LATE SATURDAY/SATURDAY NIGHT...COULD
EASILY PRODUCE PRECIP. WE MIGHT BE ABLE TO GET 2-3 DAYS OF DRY
WEATHER EARLY NEXT WEEK BEFORE ANOTHER SYSTEM MOVES THROUGH AROUND
MIDWEEK.
&&
.AVIATION...
070500Z...VARIOUS CIGS OF 1500-5000 FT MSL AND VIS 2-4 SM IN AREAS
OF HEAVIER RAINFALL WILL CONTINUE AT TIMES THROUGH THU AS SHOWERS
MOVE ACROSS THE REGION. ISOLATED TSRA ARE POSSIBLE THROUGH THE
PERIOD. GUSTY WESTERLY WINDS WILL DEVELOP LATE TONIGHT AND CONTINUE
THROUGH THU...MAINLY OVER THE MTNS AND ALONG DESERT MOUNTAIN SLOPES.
&&
.MARINE...
900 PM...WESTERLY WINDS GUSTS NEAR 25 KTS WILL CONTINUE
OVER THE COASTAL WATERS THROUGH FRIDAY. HEAVY TO MODERATE RAIN AND
PERIODS OF THUNDERSTORMS WILL ALSO OCCUR THROUGH THE PERIOD. SEAS
WILL CONTINUE TO SLOWLY INCREASE INTO THE DAY ON THURSDAY. SEAS WILL
BE 9 TO 12 FT THROUGH FRIDAY...WITH 11 TO 16 FT SEAS EXPECTED
THURSDAY. SEE THE SMALL CRAFT ADVISORY FOR ADDITIONAL
DETAILS...LAXMWWSGX. WINDS AND SEAS WILL DECREASE BY SATURDAY...BUT
PERIODS OF SHOWER ACTIVITY WILL REMAIN POSSIBLE INTO NEXT WEEK.
&&
.BEACHES...
900 PM...AN ELEVATED WEST SOUTHWEST SWELL WILL CONTINUE
TO BUILD THE SURF INTO THURSDAY. SURF OF 7-12 FT WITH SETS NEAR 15
FT ALONG FAVORED WEST FACING BEACHES IS POSSIBLE BY THURSDAY..WITH
HIGHEST SETS EXPECTED IN SAN DIEGO COUNTY. COASTAL FLOODING AND
POTENTIAL DAMAGE TO COASTAL STRUCTURES...SUCH AS PIERS...WILL BE
POSSIBLE ON THURSDAY. FOR ADDITIONAL DETAILS...SEE THE LAXCFWSGX.
THE SURF WILL REMAIN HIGH ON FRIDAY...WITH LOWER SURF EXPECTED OVER
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.HYDROLOGY... THE SAN DIEGO RIVER AT FASHION VALLEY IS CURRENTLY AT
10.6 FEET (9:15 PM) BUT APPEARS TO BE CRESTING NOW. WE COULD STILL
GO ABOVE FLOOD STAGE FOR AWHILE TONIGHT.
ADDITIONAL RAINFALL WILL BE MORE VARIABLE DUE TO THE SHOWERY
ACTIVITY...BUT VALUES WILL MOSTLY BE 0.75 TO 1.5 INCHES...WITH SOME
LOCATIONS IN THE MOUNTAINS RECEIVING 2 OR MORE ADDITIONAL INCHES
THROUGH THURSDAY. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 11
AM THURSDAY FOR AREAS OVER AND WEST OF THE MOUNTAINS BELOW 4500 FOOT
ELEVATION.
PRECIP AMOUNTS WILL BE SUBSTANTIALLY LESS AFTER THURSDAY...MOSTLY
UNDER 0.5 INCHES THU NIGHT/FRI. AMOUNTS FOR SAT/SAT NIGHT DO NOT
LOOK EXCESSIVE RIGHT NOW...LIKELY UNDER 0.5 INCHES IN MOST AREAS.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT CURRENTLY REQUESTED BUT COULD BE REQUESTED
AGAIN THURSDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR ORANGE COUNTY
COASTAL AREAS-ORANGE COUNTY INLAND AREAS-RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO
AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO
COUNTY COASTAL AREAS-SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO
COUNTY VALLEYS-SAN GORGONIO PASS NEAR BANNING-SANTA ANA
MOUNTAINS AND FOOTHILLS.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY FOR SAN DIEGO COUNTY
MOUNTAINS.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY FOR RIVERSIDE COUNTY
MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS.
BEACH HAZARDS STATEMENT THROUGH THURSDAY MORNING FOR ORANGE
COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
HIGH SURF WARNING UNTIL 10 PM PST FRIDAY FOR ORANGE COUNTY
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
PZ...SMALL CRAFT ADVISORY UNTIL 4 PM PST FRIDAY FOR COASTAL WATERS
FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT TO 30 NM-
WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING
30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND.
&&
$$
PUBLIC/HYDROLOGY...MAXWELL/HARRISON
AVIATION/MARINE/BEACHES...JTT
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
938 PM PST WED JAN 6 2016
.SYNOPSIS...
ACTIVE WEATHER PATTERN CONTINUES TO IMPACT NORTHERN CALIFORNIA
THIS WEEK AND INTO THE WEEKEND. MOUNTAIN SNOW AND VALLEY RAIN
THROUGH THIS EVENING WITH LINGERING SHOWERS ON THURSDAY. STILL
LOOKS LIKE FRIDAY WILL BE A RELATIVELY DRY DAY MOST AREAS WITH
ANOTHER ROUND OF RAIN AND MOUNTAIN SNOW EXPECTED FRIDAY NIGHT
INTO SATURDAY.
&&
.DISCUSSION...
A band of rain extending through the delta and Sacramento area
extends to the northeast up into Plumas County. Elsewhere
scattered showers are persisting. The HRRR model indicates the
band to persist for the next 2 to 3 hours before gradually
dissipating. The HRRR indicates the band should not be bringing
the current higher rainfall rates to the higher elevations of the
western slopes. Snowfall has tapered but is expected to continue
at times for a good portions of the night. Only expecting 1 to 2
inches of additional snowfall so will let the Winter Storm Warning
expire but put up a Winter Weather Advisory until 4 am.
A circulation will remain off of Oregon as the low splits with the
bulk of the low pressure area moving southeast of the area.
Chances of showers will persist on Thursday with the better
chances over the mountains. As the weaker low moves over the far
northern areas Thursday night showers may persist. The low
continues to drop southeast and into the Great Basin on Friday and
the interior should be drying out during the daytime.
The models are indicating a system Friday night and Saturday that
looks like it should bring us a decent round of rainfall and snow
for the mountains. Both today and tonight`s model runs are
indicating the storm is stronger than yesterday. Snow levels will
again be on the lower side and similar to this current storm.
Winds will become breezy as the front move through but at this
time do not look as strong. The rain will change over to showers
from west to east during the day and gradually diminish Saturday
night.
&&
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
Model consensus in the EFP is the only relatively dry day in Norcal
will be Sun...possibly Tue. A highly amplified ridge continues along
the W Coast early next week...which periodically gets displaced or
flattened by migratory/progressive trofs.
Dry Nly flow is forecast over Norcal on Sun as Sat`s system moves
into the Desert SW. Ridging builds over Norcal during the day which
brings a break in the wet pattern.
The GFS is faster than the ECMWF in breaking down the W Coast ridge
on Mon and then re-establishing the ridge again on Tue. Meanwhile...
the slower ECMWF lingers the trof over Norcal on Tue. The model
differences lead to low confidence and inclusion of at least a low
PoP into Tue for Norcal in what would be a light to modest precip
at best.
Similarly for Wed...the GFS is more progressive in what looks to be
a slightly wetter (but still modest) trof than Mon`s. Obviously...
the EFP details will need to be sorted out in later forecasts.
JHM
&&
.AVIATION...
S-SWly flow alf bcms NWly Thu as upr low movs into Grt Basin and
ofshr upr rdg apchs. In Intr NorCal, wdsprd MVFR with areas IFR
and lcl LIFR ovngt. Conds impvg in Cntrl Vly aft 19z Thu but
contd areas trrn obscd omtns in shwrs. Sn lvls arnd 030 ft. Sfc
wnds dcrsg this eve.
&&
.STO Watches/Warnings/Advisories...
Winter Weather Advisory until 4 AM PST Thursday for Western
Plumas County/Lassen Park.
Winter Weather Advisory until 4 AM PST Thursday for West Slope
Northern Sierra Nevada.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1142 PM CST WED JAN 6 2016
...AVIATION UPDATE...
.UPDATE...
ISSUED AT 814 PM CST WED JAN 6 2016
LATEST WATER VAPOR IMAGERY SHOWS THE SHORTWAVE TROUGH AXIS MOVING
THROUGH CENTRAL IA...WITH AREA RADARS SHOWING ASSOCIATED
PRECIPITATION OVER CENTRAL INTO EAST CENTRAL IA. BASED ON SURFACE
OBSERVATIONS...THE PRECIPITATION IS MAINLY SNOW NW OF A DSM TO ALO
LINE...WITH LIGHT RAIN OR DRIZZLE TO THE SOUTHEAST WHERE SURFACE
TEMPERATURES WERE ABOVE 32. AN AREA OF ENHANCED REFLECTIVITY MOVING
ALONG THE I-80 AXIS WEST OF IOWA CITY INDICATES POSSIBLE SLEET
OCCURRING...SUPPORTED BY A SHALLOW SUB FREEZING LAYER ON KDVN
SOUNDING AROUND 500 TO 1500 FT AGL.
THE BULK OF THE PRECIPITATION APPEARS TO BE ON TRACK TO REMAIN
MAINLY NORTH OF I-80 AHEAD OF THE PASSING SHORTWAVE AND HAVE
UPDATED THE FORECAST TO SIMPLIFY TO A SNOW/SLEET MIX EARLY...THEN
LIGHT SNOW CHANGING TO LIGHT RAIN OVERNIGHT AS WARM ADVECTION SW
FLOW WARMS THE ENTIRE SUB 850 MB LAYER ABOVE FREEZING FROM SOUTH
TO NORTH OVERNIGHT TO NEAR THE HIGHWAY 20 CORRIDOR BY SUNRISE.
WITH UPSTREAM REPORTS SHOWING RATES AROUND .01 TO .02 PER HOUR AND
LIFT RAPIDLY SPREADING NORTHEAST...OVERNIGHT QPF SHOULD BE LESS
THAN A TENTH OF AN INCH WITH NEGLIGIBLE SNOWFALL. TO THE SOUTH
AND SE...LIFT IS WEAKER AND PRIMARILY DUE TO WARM/MOIST ADVECTION
ALOFT. ANY PRECIPITATION WILL HAVE TO OVERCOME DRY AIR IN THE LOW
LEVELS AND WILL ANTICIPATE PATCHY LIGHT LIGHT RAIN OR DRIZZLE
THROUGH THE REST OF THE NIGHT WITH NEAR STEADY TEMPERATURES AND
PAVEMENT TEMPERATURES HOLDING ABOVE FREEZING.
&&
.SYNOPSIS...
ISSUED AT 322 PM CST WED JAN 6 2016
HIGH PRESSURE WAS LOCATED ACROSS THE EASTERN SEABOARD AS A
DEVELOPING SURFACE LOW TOOK SHAPE ACROSS THE LEE OF THE ROCKIES. S
FLOW AT THE SFC A LONG WITH A SHORTWAVE ALOFT AIDED IN BRINGING
IN WARMER AND MORE MOIST AIR INTO THE REGION THIS AFTERNOON.
PRECIP ASSOCIATED WITH THIS INITIAL WAVE STRUGGLED TO REACH THE
GROUND AS DRY AIR WAS IN PLACE. THIS WILL CHANGE WITH THE
ADVECTION OF WARMER AIR...DEEPER MOISTURE AND ANOTHER WAVE AFFECTS
THE AREA THROUGH THE SHORT TERM.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 322 PM CST WED JAN 6 2016
MAIN FORECAST CONCERN IN THE SHORT TERM ARE THE THERMODYNAMICS AND
THE ASSOCIATED PRECIP TYPES WITH THEM. THERMAL PROFILES HOVER
AROUND FREEZING FROM THE SFC TO ALOFT...THIS IS LEADING TO A
TRICKY FORECAST ACROSS THE AREA. REGARDLESS...THE AREA IS EXPECTED
TO SEE MEASURABLE PRECIP THROUGH THE SHORT TERM....WITH MOST
LIQUID QPF VALUES LESS THAN 0.25 INCHES..EXCEPT FOR THE MO
COUNTIES THAT MAY SEE UNDER 0.5 INCHES.
FORECAST CHALLENGES ABOUND WITH DIFFICULT PTYPE FORECAST AND
POSSIBLE IMPACTS. GRIDDED AND SPECTRAL SYNOPTIC SCALE MODELS
SUGGEST THAT THE AREA WILL STAY COOLER LONGER...LEADING TO MORE OF
A MIX OF FZRA...RA..AND SN ACROSS THE AREA. WHEREAS THE RUC AND
OTHER CAMS ARE MORE INDICATIVE OF A QUICK CHANGE TO RAIN FROM
SNOW. THIS IS AT ODDS WITH THE TRADITIONAL WARM FRONT MODEL WITH
WARMING ALOFT THAT WOULD LEAD TO MIXED PRECIP. WOULD BE MORE
CONFIDENT IN A SOLUTION IF I SAW THE DEWPOINTS RISING AS WELL WITH
THE SFC TEMPS. CONCERNED THAT EVAPORATIVE COOLING COULD LEAD TO A
LARGER AREA OF FZRA...MORE LIKE THE SYNOPTIC SCALE MODELS.
AT THIS TIME WILL GO WITH A MIX MAINLY NORTH OF HWY 30 TONIGHT.
CLOSER TO 12Z AN AREA OF FZRA COULD FORM NEAR I80 BEFORE A
CHANGEOVER TO ALL RAIN. THERE COULD BE TRAVEL ISSUES EARLY IN THE
AM BEFORE THE FZRA SWITCHES OVER TO ALL RA IN THE MID AM. NORTH OF
HIGHWAY 30 COULD SEE SOME SLEET AND FZRA IN THE AM...THIS COULD
LEAD TO SOME TRAVEL ISSUES ACROSS THE NORTHERN ZONES. THE PLUS TO
THIS IS THAT WHATEVER FALLS OVERNIGHT AND TOMORROW AM WILL MELT
WITH THE RA IN THE AFTERNOON TOMORROW. OVERALL QPF AMOUNTS ARE
LOW...BUT WITH THE LIGHT RAIN RATES..THINK THAT A THIN GLAZE OF
ICE COULD COAT SOME ELEVATE OBJECTS AND POSSIBLY UNTREATED
ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES.
IT WILL BE IMPORTANT TO WATCH THE TEMPS AND DEWPOINTS TONIGHT.
THIS WILL HELP TO DETERMINE WHETHER OR NOT MORE FREEZING RAIN OR
RAIN WILL FALL.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 322 PM CST WED JAN 6 2016
THURSDAY NIGHT AND FRIDAY...PERIODS OF LIGHT RAIN ARE LIKELY OVER
EASTERN IOWA/WESTERN ILLINOIS/AND NORTHEAST MISSOURI. THE FIRST WAVE
SHOULD BE ONGOING FRIDAY EVENING...LASTING INTO THE FIRST HALF OF
THE NIGHT. TIME-HEIGHT SECTIONS SUGGEST THIS ROUND TO BE DRIVEN
MAINLY BY WARM AIR ADVECTION BETWEEN 850-700MB. SFC TEMPS SHOULD
HOLD STEADY OVERNIGHT THURSDAY IN THE SE SFC FLOW. EXPECTING LOWS IN
THE 33-34 F RANGE ACROSS THE NORTH ALONG HIGHWAY 20...MID 30S ALONG
I-80...AND MID TO UPPER 30S SOUTH OF HIGHWAY 34.
THEN AS THE WEAK 1005MB SFC LOW PULLS NORTHEASTWARD ACROSS E IOWA ON
FRIDAY WINDS ARE FORECAST TO VEER TO A MORE SOUTHERLY DIRECTION
THEREBY PULLING THE THERMAL RIDGE/THETA-E GRADIENT NORTHWARD INTO THE
DVN CWA. HAVE UPPER 40S IN THE FAR SOUTH...LOWER 40S NEAR THE QUAD
CITIES AND MID 30S FAR NORTH FOR HIGHS. THE 500MB VORTICITY MAX AND
ATTENDANT DCVA WILL CROSS THE REGION DURING THE DAY BRINGING A
SECONDARY WAVE OF LIGHT RAIN. A VERY LOW OVERCAST IS LIKELY AND
PERIODS OF DRIZZLE ARE POSSIBLE BASED ON THE SATURATED FORECAST
SOUNDINGS.
SATURDAY...A COMPACT SHORTWAVE IS FORECAST TO RIDE THE SW-TO-NE
ORIENTED 850MB BAROCLINIC ZONE THAT WILL BE DRAPED ACROSS THE
CENTRAL U.S. INTO THE WESTERN GREAT LAKES. MODELS VARY CONSIDERABLY
ON THE TRACK/STRENGTH OF THIS LOW BUT THERE IS THE POTENTIAL FOR
ACCUMULATING SNOW IN A PORTION OF THE DVN CWA.
AT THIS TIME...THE BETTER CHANCES FOR THE STEADIEST PRECIP ARE
ACROSS THE EASTERN CWA OR EAST OF THE MISSISSIPPI RIVER. PLENTY OF
TIME FOR THE MODELS TO ADJUST THE EVOLUTION OF THIS
SYSTEM...THEREFORE SHIFTS TO THE NW OR EVEN THE EAST REMAIN
POSSIBLE...CANNOT GET INTO MUCH OF THE DETAILS WITH THIS MUCH MODEL
UNCERTAINTY. WHAT IS MORE OF A SURE THING THIS FAR OUT IS GUSTY
NORTHWEST WINDS...POSSIBLY IN EXCESS OF 30 MPH. FOR AREAS THAT DO
RECEIVE SNOW...THE WINDS WOULD RESULT IN A HEIGHTENED TRAVEL IMPACT.
PLEASE STAY TUNED TO THE LATEST FORECASTS OVER THE NEXT FEW DAYS.
SUNDAY...ARCTIC AIR POISED TO DUMP INTO THE MIDWEST. CONSENSUS HIGHS
RANGE FROM NEAR 5 F BY INDEPENDENCE IOWA TO AROUND 12 F IN THE QUAD
CITIES...TO THE MID TEEN BY MACOMB ILLINOIS. 850MB TEMPS ARE
PROJECTED TO BOTTOM OUT NEAR -16 C TO -18 C AND 1000-500MB
THICKNESSES TO AN IMPRESSIVELY LOW 504 DAM ON THE ECMWF AND 510 DAM
ON THE GFS.
SUNDAY NIGHT...TEMPS ARE HIGHLY CONTINGENT ON HOW MUCH SNOW IS ON
THE GROUND OR IF THERE IS ANY. CURRENT MODEL CONSENSUS FORECAST HAS
SINGLE DIGITS LOWS ABOVE AND BELOW ZERO.
WIND CHILLS...LOOK TO BE COLDEST SUNDAY NIGHT AND MONDAY MORNING.
ADVISORY LEVEL VALUES NEAR -20 F ARE POSSIBLE...ESPECIALLY ALONG AND
NORTH OF HIGHWAY 30.
MONDAY AND TUESDAY...DAYTIME HIGHS SHOULD MODERATE A BIT INTO THE
TEENS MONDAY WITH TEENS/20S ON TUESDAY PER MODEL CONSENSUS.
OVERNIGHT LOWS SHOULD REMAIN ON THE COLD SIDE...IN THE SINGLE DIGITS
AND TEENS. CONFIDENCE FOR THE TEMP FORECAST ON TUESDAY IS LOW WITH
THE GFS AND ECMWF SHOWING DIFFERENT TEMP ADVECTION PATTERNS.
A CLIPPER TYPE SYSTEM MAY BRING SOME SNOW SHOWERS TO THE WESTERN
GREAT LAKES AREA ON TUESDAY...BUT ONLY HAVE SLIGHT CHANCES OVER THE
NE SECTION OF THE DVN CWA AS MODELS ARE NOT SHOWING MUCH IN THE WAY
OF MOISTURE RIGHT NOW. UTTECH
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CST WED JAN 6 2016
LIGHT PRECIPITATION WILL CONTINUE ACROSS THE AREA OVERNIGHT
THROUGH THURSDAY WITH LOWERING CIGS AND VISIBILITIES LEADING TO
PREVAILING IFR CONDITIONS BY SUNRISE. A MIX OF RAIN AND SNOW WILL
AFFECT THE DBQ TERMINAL AFTER MIDNIGHT INTO EARLY THURSDAY
MORNING...WITH THE REMAINDER OF THE TERMINALS PREDOMINANTLY LIGHT
RAIN OR DRIZZLE WITH FOG ALSO DEVELOPING. THERE IS A LOW
POTENTIAL FOR LIGHT ICE ACCUMULATION IN THE PREDAWN HOURS AT DBQ
BEFORE TEMPERATURES RISE ABOVE FREEZING. THURSDAY...IFR AND
POSSIBLY LIFR CONDITIONS ARE EXPECTED WITH DRIZZLE GIVING WAY TO
ANOTHER ROUND OF RAIN BY EVENING FROM SOUTH TO NORTH WITH THE
NEXT UPPER LEVEL SYSTEM.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...UTTECH
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1212 AM CST THU JAN 7 2016
.AVIATION...
FOR THE ARKLATEX...NUMEROUS SHWRS STRETCH FROM KTXK...TO KSHV...TO
KJAS AND STILL WITH A BACK EDGE ON APPROACH TO KTYR TO KLFK ATTM.
THE MAIN UPPER LOW IS OVER N TX/NM AND ARCS A BAND OF RA SHOWERS
OFF THE COASTAL BEND AND IS MOVING NE AT 30KTS. THIS HEAVIER
PRECIP WILL CRASH CIGS/VSBY OVERNIGHT FOR ALL TERMINALS AND FOR
MUCH OF THURS IN IT/S WAKE WITH NO FROPA AND SE WINDS 5-10KTS.
ALOFT...WE ARE SE TO 5KFT...THEN KEEP SW/W ON UP 30-60KTS. WE MAY
SEE SOME MVFR LATE...BUT DENSE FOG LIKELY EARLY FRIDAY. /24/
&&
.PREV DISCUSSION... /ISSUED 1008 PM CST WED JAN 6 2016/
DISCUSSION...
THE EVENING WATER VAPOR IMAGERY INDICATES A DISCERNABLE SHORTWAVE
TRANSLATING E ACROSS THE ERN TX PANDHANDLE SE INTO CNTRL TX...WITH
AN AREA OF DEEPENING CONVECTION CONTINUING TO EXPAND ENE INTO E
TX. THE EXTENT OF LIGHTNING HAS DIMINISHED OVER THE LAST COUPLE
OF HOURS OVER CNTRL TX...BUT COOLING CLOUD TOPS AND 700-500MB LAPSE
RATES BETWEEN 6-6.5C/KM MAY STILL YIELD ISOLATED STRIKES WITHIN
THE EMBEDDED CONVECTION. THE AIR MASS STILL HAS A WAYS TO MOISTEN
ACROSS NCNTRL/NE LA...AS THE ISOLATED -SHRA THAT HAS DEVELOPED
ALONG AN EWD EXPANDING H850 THETA-E AXIS HAS YET TO BE SUFFICIENT
IN MOISTENING THE COLUMN. HOWEVER...THAT WILL CHANGE LATE TONIGHT
AS THE MORE ORGANIZED CONVECTION SPREADS E AND SATURATES THE
COLUMN FROM THE TOP DOWN.
HAVE UPDATED THE ZONES TO BEEF UP POPS AREAWIDE LATE TONIGHT TO
HIGH END CATEGORICAL...WITH LOW END CATEGORICAL FOR THE ERN
PARISHES OF NCNTRL LA. HAVE ALSO ADJUSTED POPS SLIGHTLY THURSDAY
MORNING BASED ON THE RECENT RUNS OF THE HRRR AND 00Z NAM...WHICH
MAINTAIN THE ORGANIZED CONVECTION OVER THE ERN ZONES THROUGH MID
MORNING BEFORE DIMINISHING FROM W TO E AS DRY SLOTTING ALOFT
SPREADS ENE IN WAKE OF THE SHORTWAVE TROUGH PASSAGE. ALSO ADJUSTED
SKY COVER TO MOSTLY CLOUDY FOR THE AFTERNOON OVER E TX...AS THE LOW
CLOUDS MAY BE STUBBORN TO COMPLETELY SCATTER OUT UNTIL LATE IN THE
DAY. ALSO MADE A FEW MINOR ADJUSTMENTS TO MIN TEMPS TONIGHT...WITH
READINGS LIKELY REMAINING STEADY OR EVEN SLOWLY RISING OVERNIGHT
AS THE RAIN BRINGS SLIGHTLY WARMER TEMPS ALOFT DOWN TO THE SFC.
OTHERWISE...THE REMAINDER OF THE FORECAST IS IN GOOD SHAPE. ZONE
UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 48 70 47 56 / 10 30 50 20
MLU 50 70 50 62 / 10 10 50 30
DEQ 41 65 42 51 / 10 20 30 20
TXK 47 67 45 53 / 10 30 40 20
ELD 47 67 46 58 / 10 20 50 30
TYR 47 69 44 52 / 10 40 30 10
GGG 46 69 45 54 / 10 40 40 10
LFK 48 69 48 58 / 10 40 50 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24/15/12
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1008 PM CST WED JAN 6 2016
.DISCUSSION...
THE EVENING WATER VAPOR IMAGERY INDICATES A DISCERNABLE SHORTWAVE
TRANSLATING E ACROSS THE ERN TX PANDHANDLE SE INTO CNTRL TX...WITH
AN AREA OF DEEPENING CONVECTION CONTINUING TO EXPAND ENE INTO E
TX. THE EXTENT OF LIGHTNING HAS DIMINISHED OVER THE LAST COUPLE
OF HOURS OVER CNTRL TX...BUT COOLING CLOUD TOPS AND 700-500MB LAPSE
RATES BETWEEN 6-6.5C/KM MAY STILL YIELD ISOLATED STRIKES WITHIN
THE EMBEDDED CONVECTION. THE AIR MASS STILL HAS A WAYS TO MOISTEN
ACROSS NCNTRL/NE LA...AS THE ISOLATED -SHRA THAT HAS DEVELOPED
ALONG AN EWD EXPANDING H850 THETA-E AXIS HAS YET TO BE SUFFICIENT
IN MOISTENING THE COLUMN. HOWEVER...THAT WILL CHANGE LATE TONIGHT
AS THE MORE ORGANIZED CONVECTION SPREADS E AND SATURATES THE
COLUMN FROM THE TOP DOWN.
HAVE UPDATED THE ZONES TO BEEF UP POPS AREAWIDE LATE TONIGHT TO
HIGH END CATEGORICAL...WITH LOW END CATEGORICAL FOR THE ERN
PARISHES OF NCNTRL LA. HAVE ALSO ADJUSTED POPS SLIGHTLY THURSDAY
MORNING BASED ON THE RECENT RUNS OF THE HRRR AND 00Z NAM...WHICH
MAINTAIN THE ORGANIZED CONVECTION OVER THE ERN ZONES THROUGH MID
MORNING BEFORE DIMINISHING FROM W TO E AS DRY SLOTTING ALOFT
SPREADS ENE IN WAKE OF THE SHORTWAVE TROUGH PASSAGE. ALSO ADJUSTED
SKY COVER TO MOSTLY CLOUDY FOR THE AFTERNOON OVER E TX...AS THE LOW
CLOUDS MAY BE STUBBORN TO COMPLETELY SCATTER OUT UNTIL LATE IN THE
DAY. ALSO MADE A FEW MINOR ADJUSTMENTS TO MIN TEMPS TONIGHT...WITH
READINGS LIKELY REMAINING STEADY OR EVEN SLOWLY RISING OVERNIGHT
AS THE RAIN BRINGS SLIGHTLY WARMER TEMPS ALOFT DOWN TO THE SFC.
OTHERWISE...THE REMAINDER OF THE FORECAST IS IN GOOD SHAPE. ZONE
UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PREV DISCUSSION... /ISSUED 624 PM CST WED JAN 6 2016/
AVIATION...
FOR THE ARKLATEX...VFR HOLDING FOR NOW WITH LIGHT SHOWERS AREA
WIDE NOT AFFECTING VSBY JUST YET. THIS IS A LEAD SHORT WAVE MOVING
OVERHEAD. THE MAIN UPPER LOW IS OVER W TX/NM ATTN AND IS ON
APPROACH WITH TSTMS OVER THE TX COASTAL BEND MOVING TOWARD KLFK AND
PUSHING OUT OF THE HILL COUNTRY FOR I-20 TERMINALS MID TO LATE
EVENING. THIS HEAVIER PRECIP WILL CRASH CIGS/VSBY OVERNIGHT AND
FOR ALL OF THURS IN IT/S WAKE WITH NO FROPA AND SE WINDS 5-10KTS.
WE MAY SEE SOME MVFR LATE...BUT DENSE FOG LIKELY EARLY FRIDAY.
/24/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 51 63 48 70 / 100 50 10 30
MLU 47 58 50 70 / 80 90 10 10
DEQ 44 57 41 65 / 100 60 10 20
TXK 46 58 47 67 / 100 50 10 30
ELD 47 56 47 67 / 90 90 10 20
TYR 49 65 47 69 / 100 20 10 40
GGG 49 65 46 69 / 100 30 10 40
LFK 52 67 48 69 / 100 20 10 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS DULUTH MN
1137 PM CST WED JAN 6 2016
.UPDATE...
ISSUED AT 932 PM CST WED JAN 6 2016
SNOW WAS FALLING OVER MUCH OF NORTHWEST WISCONSIN AND WAS
INCREASING OVER NORTHERN MINNESOTA AS WELL. A NARROW BAND OF
HEAVIER SNOW DEVELOPED OVER THE TWIN PORTS INTO EXTREME NORTHERN
WISCONSIN THIS EVENING AND IT DUMPED A QUICK HALF TO ONE INCH OF
SNOW. WE HAVE INCREASED SNOWFALL OVER MUCH OF THE AREA
TONIGHT...BUT STILL HAVE MOST AREAS FROM 1 TO 2 INCHES BY MORNING.
THE 00Z NAM FORECASTS MORE SNOWFALL OVER FAR NORTHERN MINNESOTA
AFTER 06Z...AND WE ARE SEEING A NARROW BAND FORMING BETWEEN
BIGFORK AND ELY AS OF 930 PM. POPS WERE INCREASED TONIGHT INTO
THURSDAY MORNING AND WE BUMPED UP SNOWFALL FURTHER.
CALLS TO LEC/S IN OUR SOUTHWEST CWA REVEALED FEW FREEZING DRIZZLE
REPORTS AND THE LATEST RAP SHOWED SATURATION OCCURRING AROUND OR
SHORTLY AFTER 04Z RESULTING IN MAINLY SNOW. WE STILL THINK THERE
COULD BE SOME PATCHY FREEZING DRIZZLE OVERNIGHT AND CONTINUE TO
MENTION IN THE FORECAST.
UPDATE ISSUED AT 711 PM CST WED JAN 6 2016
AREA RADARS HAVE SHOWN ECHOES INCREASING IN BOTH COVERAGE AND
STRENGTH EARLY THIS EVENING...PARTICULARLY OVER NORTHERN
WISCONSIN. THIS IS ON TRACK WITH THE FORECAST AND LATEST GUIDANCE. WE
WILL ADJUST POPS THIS EVENING TO ACCOUNT FOR THE LATEST RADAR
TRENDS.
WE INCREASED POPS OVER OUR NORTHWEST CWA LATE TONIGHT AS SEVERAL
OF THE MODELS INDICATE AN ENHANCED BAND OF SNOW WILL BE POSSIBLE
THERE. THERE WILL BE SOME MAINLY WEAK FGEN IN THAT
AREA...ESPECIALLY IN THE LOW LEVELS. BASED ON STRENGTH OF THE
FORCING...WE INCREASED POPS TO LIKELY BUT ONLY NUDGED SNOW AMOUNTS
A FEW TENTHS OF AN INCH BOTH 06Z-12Z TONIGHT AND INTO THURSDAY
MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 334 PM CST WED JAN 6 2016
S/W TROF AXIS OVER IOWA LATE THIS AFTERNOON IS ACCOMPANIED BY A
FAIRLY LARGE PRECIP SHIELD..AND THIS WAVE WILL LIFT INTO WISCONSIN
TONIGHT. KMPX/KDLH/KARX RADARS INDICATE THAT PRECIP IS TRYING TO
EXPAND NORTHEASTWARD AHEAD OF THIS FEATURE IN MODESTLY STRONG
ASCENT..BRINGING A 4-8 HOUR PERIOD OF LIGHT PRECIP TO ROUGHLY THE
SOUTHEAST THIRD TO HALF OF THE DLH CWA TONIGHT/THUR MORNING. IN
GENERAL..AS THE WAVE LIFTS NEWD..DEEP LAYER SATURATION THROUGH A
SUFFICIENTLY DEEP LAYER BELOW -10C SHOULD RESULT IN MOST OF THE
PRECIP BEING LIGHT SNOW. HOWEVER..IN AREAS WHERE THE DRY LAYER
ALOFT IS SUFFICIENTLY DEEP TO NOT BE SATURATED..AREAS OF FREEZING
DRIZZLE/FLURRIES/FOG WILL PERSIST THROUGH TOMORROW. A GENERAL 1-2
INCH EVENT IS ANTICIPATED OVER MOST OF NW WISCONSIN TONIGHT/THUR
MORNING..WITH THE TWIN PORTS AND N SHORE AREAS BEING ON THE FAR
NORTHWEST EDGE OF THE MORE ORGANIZED PRECIP AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 334 PM CST WED JAN 6 2016
A SHORTWAVE WILL LIFT NORTHWARD THROUGH WISCONSIN THURSDAY NIGHT AND
FRIDAY IN THE BROAD SOUTHERLY UPPER LEVEL FLOW AHEAD OF AN UPPER
LEVEL LOW OVER THE CENTRAL PLAINS. LIGHT EASTERLY FLOW OVER THE
NORTHLAND WILL BECOME NORTHERLY DURING THIS TIME WHEN AN INVERTED
SURFACE TROUGH SLOWLY MOVES EAST THROUGH THE NORTHLAND. THE
SHORTWAVE AND TROUGH WILL BRING WIDESPREAD LIGHT TO MODERATE SNOW
TO THE NORTHLAND THURSDAY NIGHT AND FRIDAY. NORTHWEST WISCONSIN
AND THE ARROWHEAD ARE FORECAST TO GET ABOUT 2 TO 4 INCHES...WHILE
THE REST OF NE MINNESOTA ABOUT 1 TO 3 INCHES. EARLIER FORECASTS
HAD A MIXTURE OF RAIN AND SNOW...BUT THE LATEST GFS BUFR SOUNDINGS
SUGGEST THE PROFILES ARE SUFFICIENTLY DEEPLY SATURATED AND COLD TO
RESULT IN PRIMARILY SNOW.
A STRONG COLD NW FLOW COLD AIR BLAST WILL COME FRIDAY AND THROUGH
THE WEEKEND AS A DEEP UPPER LEVEL LOW DIGS OUT OF NORTHERN CANADA TO
ONTARIO AND THE NORTHERN GREAT LAKES. THE COLD NW FLOW WILL RESULT
IN LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH SHORE SNOW BELT REGION
THROUGH SUNDAY. LOWERED TEMPERATURES FOR THE LATE WEEKEND AND EARLY
NEXT WEEK BASED ON A BLEND OF THE GFS/CANADIAN/ECMWF.
TEMPERATURES WILL BOTTOM OUT ON SUNDAY WITH HIGHS MOSTLY BELOW
ZERO DEGREES.
THERE WILL LIKELY BE SOME TEMPERATURE RECOVERY MONDAY AND
TUESDAY...BUT HIGHS WILL STILL ONLY BE IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1133 PM CST WED JAN 6 2016
AN AREA OF LOW PRESSURE ALONG WITH A PAIR OF SHORTWAVE TROUGHS
WILL COMBINE TO PRODUCE SNOW AND SOME FREEZING DRIZZLE ACROSS THE
NORTHLAND TONIGHT. THE PRECIPITATION WILL GRADUALLY DIMINISH FROM
SOUTH TO NORTH LATE TONIGHT INTO THURSDAY. MAINLY IFR OR LIFR
CONDITIONS WILL PREVAIL THROUGH THE PERIOD. THERE WERE STILL SOME
POCKETS OF MVFR CONDITIONS...BUT THOSE WILL LOWER OVER THE NEXT
COUPLE HOURS.
PRECIP TYPE WILL MAINLY BE LIGHT SNOW BUT THERE WILL STILL BE SOME
AREAS OF FREEZING DRIZZLE...ESPECIALLY SOUTH OF HIGHWAY 2.
VSBYS SHOULD REMAIN REDUCED EVEN AFTER THE MAIN AREA OF
PRECIPITATION MOVES THROUGH DUE TO FOG.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 30 29 31 / 90 50 30 50
INL 21 28 26 28 / 60 70 50 40
BRD 27 30 27 32 / 70 30 30 50
HYR 26 33 28 34 / 90 50 70 70
ASX 27 33 28 34 / 90 50 70 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1150 PM CST WED JAN 6 2016
.UPDATE:
Issued at 936 PM CST Wed Jan 6 2016
Scattered rain continues to move across the area this evening. We
got reports of flurries and light sleet with the onset of this
rain as the atmosphere evaporately cooled as the rain fell in the
dry air. No reports of accumulations have been reported thus far.
Still appears that rain will become more likely across central MO
late tonight per the HRRR and RAP as shortwave currently over
southern high Plains approaches the area. Precipitation type still
should be rain as warm air gets advected in ahead of system. RAP
is also showing an increase in low level moisture convergence over
central MO toward 12Z. Rest of forecast looks good.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CST Wed Jan 6 2016
Warm advection aloft is producing bands of weak showers across
Missouri and Illinois. Much of this precip isn`t reaching the
ground, however scattered traces and 0.01 inch rainfall amounts keep
popping up on the hourly precip map...so have kept slight chance in
the forecast across central and northeast MO and west central IL for
the rest of the afternoon. Expect the areal coverage of the showers
to increase through the night...particularly over central Missouri
late. However...the precipitation will be fighting dry air in the
lower 3000-4000ft of the atmosphere so expect the rain to be very
light...perhaps not much more than sprinkles until near sunrise.
Southerly flow and plenty of cloud cover should keep temperatures
warmer than last night. MOS temperatures in the low to mid 30s look
reasonable so have followed closely.
Carney
.LONG TERM: (Thursday through Next Wednesday)
Issued at 431 PM CST Wed Jan 6 2016
...Thursday through Saturday...
This is expected to be an active period with broad SW flow with a
couple short waves expected to affect the region. Upper flow is
initially split with polar jet well north of the US/Canadian border
and the subtropical jet digging out a broad trough across the wrn
CONUS as it dives down the West Coast...into the Rio Grand
Valley...across the nthrn Gulf of MX and eventually by the end of
the prd...up the East Coast.
Weak short wave ridging is fcst to exit the NErn FA early Thu mrng.
Very light rain and/or sprinkles should be ongoing across cntrl
MO by 12Z with a band possibly extending NW into W cntrl IL. This
band may reach as far SE as the NWrn portion of the STL metro
area. Light rain should continue across cntrl MO thru the mrng but
the main push of moisture assoc with the upper lvl support won`t
really arrive until aftn though. Rain is expected to slowly spread
NE thru the day but progress will be slow...likely taking all day
to overspread areas east of STL...as the system overcomes dry air
in the lower lvls. QPF ranges between 0.25 to 0.75 inches with the
higher amounts across cntrl MO where the best forcing and moisture
is expected to be. Trough axis passes late Thu night into Fri mrng
as the SFC low tracks from the sthrn Plains to NW MO. Precip
should lift NE thru the evng...ending across NErn zones after
midnight as the SFC low passes...though can`t rule out some
drizzle areawide. The SFC low is fcst to continue NE into the Grt
Lks by Sat mrng.
Another low amplitude mid lvl ridge builds in for Fri aftn and
Fri evng before heights begin falling again. The cold front extending
from the first SFC low is expected to become stnry across the CWA
Fri night in response to the second short wave approaching. This
system is fcst to track further south...though how far south is in
question. The NAM wants to deepen and close off the mid level
circulation Sat aftn/evng as it passes...taking the SFC low
across SErn MO and sthrn IL...which would give the area the best
chance for winter precip. But it is an outlier. The GFS is the
farthest NW taking the SFC low just NW of the STL metro...and the
ECMWF is somewhere in between. Guidance has trended NW with recent
systems so tend to lean towards the GFS solution. Rain assoc with
WAA is expected to dvlp across SErn MO Fri night and then lift NE
into sthrn IL Sat mrng...with lighter precip for cntrl and NE MO
and W cntrl IL. The heaviest QPF...on the order of 0.50 to 0.75
inches...should fall across SErn MO and sthrn IL. SFC low lifts NE
thru the CWA Sat allowing for decent CAA...esp drng the aftn.
There will likely be a nondiurnal temp trend on Sat...esp NW of
the STL metro area. I think the Schmocker rule will be in full
effect with this event meaning the precip should be ending as
temps get cold enough for a transition to snow. This system bears
watching though.
Temps will be above normal thru the prd with lows aoa normal daytime
highs both Thu and Fri nights.
It has been 10 days since the record setting rains so hoping the
half to one inch rainfall totals expected thru Sat evng do not cause
any additional flooding concerns. Even if the rain does cause
renewed flooding...it should remain minimal.
...Saturday night through Tuesday...
The system will continue to pull away Sat night with CAA in full
force in response to a 1030mb SFC ridge building in from the nthrn
Plains. Sun will be a true winter day with highs mid teens north
to low 30s south and a stiff NW wind. The center of the SFC high
drifts nearly overhead late Sun night into Mon mrng which sets
the stage for a cold night due to good radiational cooling. Min
temps by Mon mrng are expected to range from the mid single digits
north to mid teens south. Temps will already be moderating by
early next week approaching seasonal norms by Tue. A weak cold
front on Tue may drop temps a bit for Wed. Keep in mind that if
the area does receive snow Sat PM then areas with snow cover will
be even colder than the going fcst indicates.
2%
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1144 PM CST Wed Jan 6 2016
Rain will become more predominate through the period has an upper
level storm system approaches the area from the west. MVFR
ceilings currently at KUIN southwestward into west central
Missouri will move eastward and spread into KCOU and the St. Louis
metro area TAF sites later tonight and during the day tomorrow as
light rain becomes steady across the area. Wet runways can be
expected.
Specifics for KSTL: Expect spotty rain across the area tonight
into early tomorrow with VFR conditions before steady rain with
MVFR conditions moves into the area on Thursday afternoon. Wet
runways can be expected once the steady rain begins.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
315 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
THE MAIN FORECAST ISSUES REVOLVE AROUND PCPN TYPE AND PCPN AMOUNTS...
INCLUDING SOME LIGHT SNOW ACCUMULATIONS.
UPPER AIR CHARTS FROM 00Z SHOWED THE FOLLOWING MAIN FEATURES. AT
300 MB...STRONGEST WINDS (UP TO ABOUT 130 KNOTS) WERE MOVING
EASTWARD FROM THE PACIFIC ACROSS NORTHERN MEXICO. A BLOCKING
RIDGE AT 500 MB WAS CENTERED ALONG THE BORDER OF THE YUKON AND
NORTHWEST TERRITORIES...WHILE A TROUGH STRETCHED FROM THE GULF OF
ALASKA DOWN TO OFF THE CALIFORNIA COAST. AT 700 MB...THERE WAS A
LACK OF A BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS. THE COLDEST
AIR AT THIS LEVEL WAS ALONG THE WEST COAST. THERE WAS MORE OF A
THERMAL CONTRAST NOTED AT 850 MB ACROSS THE NORTHERN AND CENTRAL
PLAINS...WITH -8 C AT KBIS...RANGING TO +2C AT KTOP. THE KOAX
SOUNDING SHOWED ABOUT 0.51 INCHES OF PW...AND IT WAS NEARLY
SATURATED UP TO 6000 FEET AGL. SFC ANALYSIS EARLY THIS MORNING
SHOWED LOW PRESSURE CENTERS OVER COLORADO AND EASTERN SOUTH
DAKOTA. SOUTHEAST SURFACE WINDS WERE IN PLACE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH TEMPERATURES IN THE LOWER AND
MID 30S.
A SHORTWAVE HAD MOVED ACROSS THE CENTRAL PLAINS YESTERDAY...AND WAS
MOVING TOWARD THE WESTERN GREAT LAKES REGION. THE NEXT SHORTWAVE OF
CONCERN WAS DEPICTED FAIRLY WELL WITH A COMBINATION OF RECENT WATER
VAPOR SATELLITE IMAGERY AND RUC MODEL INITIALIZATIONS...NEAR THE
BORDER OF NEW MEXICO...TEXAS AND OKLAHOMA. THAT FEATURE SHOULD MOVE
TOWARD CENTRAL KANSAS BY LATE AFTERNOON AND HELP BRING INCREASING
MOISTURE (DEEPER) AND LIFT TO THE LOCAL AREA. AREAS OF DRIZZLE...
FOG AND LIGHT RAIN SHOULD PERSIST THIS MORNING...WITH LIGHT RAIN
BECOMING MORE WIDESPREAD IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
THIS AFTERNOON. THERE WILL BE A CHANCE OF A MIX OF SNOW...SLEET
AND RAIN IN MUCH OF NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
THE SHORTWAVE TROUGH THAT IS EXPECTED TO BE OVER KANSAS BY LATE
AFTERNOON WILL TRACK NORTHEAST INTO SOUTHERN IOWA FRIDAY AND WEAKEN.
THEN A MORE COMPLEX LIFT PATTERN WILL OCCUR AS ANOTHER DISTURBANCE
LIFTS EAST/NORTHEAST ACROSS KANSAS FRIDAY NIGHT INTO SATURDAY
MORNING AND A COLD TROUGH STARTS DIGGING INTO THE NORTHERN PLAINS.
MIXED PCPN SHOULD CHANGE TO MOSTLY SNOW IN NORTHEAST NEBRASKA AS
WINDS SHIFT TO THE NORTH TONIGHT AND A FEW INCHES OF SNOW MAY
ACCUMULATE. COLDER AIR WILL SPREAD OVER THE REST OF THE AREA FOR
LATE TONIGHT AND THROUGH FRIDAY...WHICH WILL CHANGE THE PCPN TO
MAINLY SNOW FROM NORTHWEST TO SOUTHEAST BY FRIDAY NIGHT. THE SNOW
SHOULD END SATURDAY...AS COLD HIGH PRESSURE STARTS TO BUILD INTO
THE AREA. BY 00Z SUNDAY...HIGH PRESSURE WITH A CENTER OF ABOUT
1031 MB SHOULD BE OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
COLD AIR SHOULD DOMINATE THE FIRST PART OF THIS PERIOD...AS A COLD
NORTH/NORTHWEST FLOW ALOFT BRINGS CANADIAN AIR DOWN INTO OUR AREA.
TEMPERATURES ARE EXPECTED TO MODERATE A BIT BY WEDNESDAY AND
THURSDAY...AS THE FLOW TURNS MORE TOWARD THE WEST. AT THIS TIME...
NO SIGNIFICANT PCPN IS EXPECTED. LIGHT SNOW IS POSSIBLE MONDAY
OVER THE DAKOTAS AND MINNESOTA. AT THIS TIME...EXPECT THAT TO STAY
TO THE NORTH OF OUR AREA.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1122 PM CST WED JAN 6 2016
LIFR OR IFR CIGS AND VSBY WILL CONTINUE THROUGH MUCH OF THE PERIOD
AS NEXT UPPER LEVEL SYSTEM APPROACHES THE CENTRAL PLAINS REGION.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
405 AM EST THU JAN 07 2016
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO GRADUALLY WEAKEN
AS IT RETREATS TO THE NORTHEAST THROUGH EARLY THURSDAY.
MEANWHILE...A SERIES OF UPPER DISTURBANCES WILL BEGIN TO CROSS THE
REGION IN SOUTHWESTERLY FLOW ALOFT LATE THIS WEEK...LEADING TO
UNSETTLED WEATHER FOR THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM THURSDAY..
HIGH PRESSURE...MAINTAINED BY SHORTWAVE RIDGING ALOFT...CONTINUES TO
EXTEND FROM THE MID-ATLANTIC STATES THROUGH THE NC PIEDMONT...WITH A
FAIRLY PRONOUNCED INVERTED TROUGH OFFSHORE. ALOFT...THE FLOW IS
GENERALLY WEAK SOUTHWESTERLY WITH DISTURBANCES OFF THE GA/FL COAST
AND OVER THE SOUTHERN PLAINS. A SHALLOW LAYER OF MOISTURE IN
SOUTHEASTERLY FLOW ATOP THE SURFACE RIDGE HAS LED TO WIDESPREAD
STRATUS AND A SMALL AREA OF RECENTLY EXPANDING DRIZZLE JUST EAST OF
THE TRIANGLE AREA...WHICH ITSELF APPEARS TO BE FOCUSED WITHIN THE
REGION OF STRONGEST 925MB WARM ADVECTION. THE MOISTURE IS
SHALLOW...THOUGH SLIGHTLY DEEPER TOWARD THE COAST...AND LUCKILY
DEWPOINTS HAVE RECOVERED INTO THE 30S EVERYWHERE EXCEPT FOR THE FAR
WESTERN PIEDMONT. THIS POORLY RESOLVED AREA OF DRIZZLE SHOULD SHIFT
NORTH-NORTHWESTWARD THIS MORNING AND NOT CAUSE ANY PROBLEMS.
OTHERWISE TODAYS FORECAST CHALLENGE IS WHETHER OR NOT THE STRATUS
WILL PERSIST THROUGH THE DAY. THE 925NMB FLOW SHOULD BACK TO MORE
NORTHEASTERLY THIS MORNING IN RESPONSE TO THE AREA OF LOW PRESSURE
DEVELOPING WELL OFF THE SOUTHEAST COAST...AND THUS THE WARM
ADVECTION WILL DIMINISH. THE NAM AND GFS MAINTAIN THE STRATUS
THROUGH THIS AFTERNOON ON THE EAST WHERE THE MOISTURE IS ALREADY
DEEPER...WHILE BREAKING THE WESTERN PIEDMONT OUT. RAP RUNS HAVE
TENDED TO SCATTER OUT THE ENTIRE AREA. WILL TREND THE FORECAST
TOWARD A LITTLE LESS CLOUD COVER BY THIS AFTERNOON...ADMITTEDLY WITH
LOW CONFIDENCE. HIGHS MAY FEATURE A MORE EVEN DISTRIBUTION THAT
USUAL...WITH MID AND UPPER 40S FOR MOST AREAS. HOWEVER...IF CLOUDS
DO SCATTER THEN LOWER 50S ARE POSSIBLY FOR THE EASTERN HALF OF THE
AREA.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 340 AM THURSDAY...
WHAT MOISTURE IS STILL AROUND THIS EVENING SHOULD LEAD TO
REDEVELOPING STRATUS BENEATH THE INVERSION ALOFT TONIGHT.
MEANWHILE... THE AFOREMENTIONED UPPER DISTURBANCE OVER THE SOUTHERN
PLAINS WILL LIFT TOWARD THE UPPER MIDWEST TONIGHT AND FRIDAY..WHILE
THE EASTERN EXTENT OF THE TROUGH AXIS AND DCVA LIFT ACROSS THE
SOUTHEAST US. THE LEFT EXIT REGION OF THE STJ WILL PROVIDE SOME
UPPER DIVERGENCE...BUT LOW-LEVEL FORCING IS LACKING WITH THE COASTAL
TROUGH STAYING PUT AND PRETTY WEAK LOW-LEVEL FLOW/ADVECTION. THE
TREND IN THE MODELS TOWARD A DRIER FORECAST HAS STABILIZED AND THE
NAM/GFS/ECMWF ALL INDICATED JUST SOME VERY LIGHT SHOWERS DURING THE
DAY ON FRIDAY. WILL MAINTAIN A SLIGHT CHANCE TO CHANCE POP AFTER
12Z FRIDAY AND NO POPS FRIDAY NIGHT AHEAD OF THE NEXT SYSTEM TO
IMPACT THE AREA ON SATURDAY.
LOWS TONIGHT WILL DEPEND HOW MUCH WE SCATTER OUT TODAY AND HOW
QUICKLY CLOUDS INCREASE OVERNIGHT AHEAD OF THE APPROACHING TROUGH.
GIVEN NO CHANGE IN THE AIR MASS AND POTENTIAL FOR OVERCAST
AGAIN...LOWS SHOULD BE SIMILAR TO THIS MORNING...34-42 NW TO SE.
HIGHS FRIDAY COULD BE LOWER WITH MORE PRECIP...BUT WILL STILL
FEATURE A CAD-LIKE RANGE GIVEN THE SURFACE HIGH AND DIABATIC EFFECTS
OF THE LOW CLOUDS...MID 40S NW TO MID 50S SOUTHEAST. AND FINALLY
FRIDAY NIGHT LOWS WILL BE A TAD MILDER IN THE 40-48 RANGE AS
DEWPOINTS CREEP UP INTO THE LOWER 40S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 400 AM THURSDAY...
FORECAST CONFIDENCE CONTINUES TO INCREASE WITH RESPECT TO THE NEXT
RELATIVELY SIGNIFICANT SYSTEM EXPECTED TO AFFECT CENTRAL NC WITH A
HIGH PROBABILITY OF RAIN...AND ASSOCIATED WEAK HYBRID COLD AIR
DAMMING...EARLY THIS WEEKEND. IN FACT...THE MODELS ARE IN GOOD
OVERALL AGREEMENT REGARDING THE SYNOPTIC PATTERN...ONE CHARACTERIZED
BY A PRIMARY SURFACE LOW TRACK INTO THE GREAT LAKES AND SECONDARY
DEVELOPMENT ALONG A RETREATING COASTAL FRONT FROM THE GULF COAST TO
THE MIDDLE ATLANTIC PIEDMONT SAT-SAT NIGHT. THE PASSAGE OF THE
SECONDARY/TRIPLE POINT LOW AND ASSOCIATED LOW LEVEL THETA-E
ADVECTION MAY ALSO SUPPORT A FEW ELEVATED STORMS DURING THE
AFTERNOON AND EVENING SAT. THE EARLIER INDICATED FASTER TREND WITH
THIS SYSTEM REMAINS...WITH MOST OR ALL OF THE SHOWERS EAST AND
NORTHEAST OF CENTRAL NC BY DAYBREAK SUNDAY.
OTHERWISE...THE PATTERN FOR EARLY TO MID NEXT WEEK APPEARS TO BE A
RELATIVELY COOL AND DRY ONE...AS A BROAD TROUGH BECOMES ESTABLISHED
ACROSS THE EASTERN TWO THIRDS OF THE COUNTRY. THE ONE EXCEPTION WILL
BE A BRIEF PERIOD OF LIFT AS A SHORTWAVE TROUGH AND ACCOMPANYING JET
STREAK IN NW FLOW ALOFT AMPLIFY ACROSS THE APPALACHIANS LATE TUE
NIGHT-EARLY WED...AT WHICH TIME A FEW FLURRIES OR SPRINKLES WOULD BE
POSSIBLE IN AN OTHERWISE DRY REGIME BETWEEN UPSLOPE APPALACHIAN
PRECIPITATION AND OFFSHORE LOW PRESSURE...THE LATTER OF WHICH WOULD
BE SUPPORTED ALOFT BY THE AFOREMENTIONED SHORTWAVE TROUGH IN NW FLOW
ALOFT...WHICH MAY GRAZE COASTAL AREAS OF THE NORTHERN MIDDLE
ATLANTIC STATES AND/OR NEW ENGLAND ON WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 100 AM THURSDAY...
SOUTH-SOUTHEASTERLY FLOW JUST ABOVE THE SURFACE HAS ADVECTED A
SHALLOW LAYER OF MOISTURE ACROSS CENTRAL NC...WITH MVFR CEILINGS NOW
BLANKETING THE AREA. THE MOISTURE IS A LITTLE DEEPER OVER THE
COASTAL PLAIN...WHERE A PERIOD OF IFR CEILINGS IS POSSIBLE PRIOR TO
12Z...AND THEN MVFR CEILINGS ARE MOST LIKELY TO PERSIST THROUGH THE
DAY. TO THE WEST AT KGSO AND KINT...WHERE THE MOISTURE IS MUCH MORE
SHALLOW...MODELS SHOW A BETTER CHANCE OF THE CEILINGS BREAKING BY
MIDDAY. MODELS HAVE STRUGGLED WITH THIS SHALLOW MOISTURE..SO
CONFIDENCE IS BELOW AVERAGE AT THIS POINT.
OUTLOOK...A COUPLE OF LOW PRESSURE SYSTEMS WILL IMPACT THE REGION
THROUGH THE WEEKEND. DESPITE VERY LITTLE RAIN WILL THE FIRST
SYSTEM ON FRIDAY...MVFR/IFR CEILINGS ARE EXPECTED...CONTINUING
THROUGH SATURDAY AS A STRONGER SYSTEM BRING WIDESPREAD RAIN.
IMPROVING CONDITIONS ARE EXPECTED BY SUNDAY AND MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...22
SHORT TERM...22
LONG TERM...2
AVIATION...22
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
345 AM EST THU JAN 7 2016
.SYNOPSIS...
HIGH PRESSURE WILL PUSH DOWN THE COAST THROUGH FRIDAY WHILE A
COASTAL FRONT LINGERS OFFSHORE. A WEAK MID LEVEL IMPULSE WILL
BRING A CHANCE FOR SHOWERS ON FRIDAY. A WARM FRONT WILL LIFT
ACROSS THE AREA SATURDAY BRINGING GOOD CHANCES FOR RAIN INTO
SUNDAY ALONG WITH MUCH WARMER TEMPERATURES. MUCH COLDER
TEMPERATURES WILL FOLLOW A COLD FRONT EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...WEAKENING HIGH PRESSURE WEDGE THE PRIMARY
FEATURE TODAY AND TONIGHT ACCOMPANIED BY MULTIPLE CLOUD LAYERING.
SOUTHERLY WINDS ABOVE 500 MB WILL DIRECT A COAT OF CIRRUS THROUGH
SC AND THE DEEPER INTERIOR OF SE NC...WITH A SMATTERING OF LOW
CLOUDS TRAPPED BENEATH A NOTABLE INVERSION TODAY. A TROUBLESOME
SKY FORECAST AS VARIABILITY IS EXPECTED NEAR THE COAST WITH MORE
STUBBORN COVERAGE LIKELY INLAND. THIS COMPLICATES MAXIMUM TEMPS
BUT MIDDLE 50S WELL INLAND TO NEAR 60 AT THE COAST ANTICIPATED.
STEERING FLOW WILL KEEP OCEAN SHOWERS MAINLY AT SEA AND THERE IS
LITTLE FORCING OVER LAND TO TRIGGER PCPN TODAY. AN EXCEPTIONALLY
DRY MID-LAYER WILL HOLD ITS GROUND TODAY. TONIGHT SHORT-WAVE
IMPULSING AND WEAK ISENTROPIC OMEGA FROM THE SW WILL ARRIVE IN
THE PRE-DAWN HOURS AND A SLIGHT CHANCE OF RAIN FOR SC INTO DAWN.
MINIMUMS LOW/MID 40S INLAND...AND UPPER 40S TO NEAR 50 COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...MID-LEVEL IMPULSE MOVING OVERHEAD FRIDAY
WILL COMBINE WITH INCREASING ISENTROPIC LIFT ALONG THE 300K SURFACE
ATOP A SURFACE WEDGE OF HIGH PRESSURE TO CREATE CLOUDS AND SHOWERS
DURING THE AFTERNOON. THERE CONTINUES UNCERTAINTY INTO HOW
SIGNIFICANT THE QPF WILL BE FROM THIS SETUP...AND GUIDANCE HAS
CONTINUED TO BACK OFF ON TOTAL RAINFALL FORECASTS ON FRIDAY. 700MB
OMEGAS ARE FOCUSED JUST OFFSHORE...COINCIDENT WITH THE BEST
PVA...WHILE ISENTROPIC LIFT NEVER BECOMES VERY STRONG OR STEEP. THIS
SUGGESTS THERE MAY BE PERIODS OF VERY LIGHT SHOWERS FRIDAY
AFTN...WITH SOME BETTER RAIN POSSIBLY JUST OFF THE COAST. THIS
MATCHES WELL WITH WPC QPF GRAPHICS FOR FRIDAY...AND AND HESITANT
TO INCREASE POP ANYTHING ABOVE THE INHERITED LOW-CHC. FRIDAY WILL
NOT BE A VERY NICE DAY...AND THE MAV TEMPS HAVE STEADILY WALKED BACK
TOWARDS THE COOLER ECS/MET NUMBERS WHICH SUPPORT THE STRONGER WEDGE.
WITH MID-LEVEL RIDGING AMPLIFYING TO THE EAST PRODUCING INCREASING
SW FLOW ALOFT...STILL BELIEVE THE MET/ECS CAMP IS TOO LOW...BUT WILL
LOWER HIGHS FRIDAY 1-2 DEGREES ACROSS THE BOARD. LIFT AND FORCING
MOVE OFF TO THE NE FRIDAY NIGHT...LEAVING IMPROVING CONDITIONS WITH
LOWS IN THE MID AND UPR 40S.
SATURDAY REMAINS A TRICKIER FORECAST DUE TO THE APPROACH OF A LOW
PRESSURE FROM THE SW AND THE PASSAGE OF A WARM FRONT SATURDAY AFTN.
THE GUIDANCE HAS SPED UP TIMING OF FEATURES EMBEDDED WITHIN STRONG
SW MID-LEVEL FLOW...AND THIS HAS CREATED A CLOUDIER...AND
RAINIER...SATURDAY FORECAST. LOW PRESSURE WILL MOVE NEAR THE SPINE
OF THE APPALACHIANS...BUT ITS WARM FRONT WILL LIFT NORTH ACROSS THE
CWA SATURDAY AFTN. THIS BRINGS RAPIDLY WARMING TEMPERATURES...AND
HIGHS SATURDAY WILL CLIMB WELL INTO THE 60S...AND MAY APPROACH 70 IN
THE EASTERN ZONES DEPENDING ON CLOUD COVER. INCREASING RAIN CHANCES
WILL ALSO ACCOMPANY THIS BOUNDARY...ESPECIALLY SATURDAY NIGHT.
STRONG LLJ NOSES INTO THE REGION AHEAD OF THE COLD FRONT SATURDAY
NIGHT...SO AS NOTED BY PREVIOUS FORECASTER...SHOWERS COULD BECOME
GUSTY LATE IN THE PERIOD...ALTHOUGH INSTABILITY IS LACKING. BY
SUNDAY MORNING THE COLD FRONT ASSOCIATED WITH THE LOW MOVING
NORTHEAST WILL BE ON THE DOORSTEP TO THE CWA. LOWS SATURDAY NIGHT
WILL REMAIN VERY WARM...MID 50S...AS THE WARM SECTOR PERSISTS
LOCALLY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...LINGERING SHOWERS EARLY SUNDAY WILL RAPIDLY
DISSIPATE AS A COLD FRONT CROSSES THE AREA SUNDAY MORNING AND PRECIP
EJECTS OFF TO THE NORTHEAST. THIS IS A TRUE ARCTIC FRONT...AND
STRONG COLD ADVECTION WILL FOLLOW AFTER A WARM FIRST PART OF SUNDAY.
AN ATYPICAL DIURNAL CURVE IS PROBABLE SUNDAY...BUT HIGHS SUNDAY
WILL LIKELY STILL BE ABOUT 10 DEGREES ABOVE NORMAL THANKS TO THE
EARLY MORNING WARM TEMPERATURES.
THEREAFTER...A RETURN TO SEASONABLE OR EVEN BELOW SEASONABLE
TEMPERATURES IS FORECAST. NOT ONLY IS STRONG CAA EXPECTED SUNDAY
NIGHT THROUGH TUESDAY AS 850MB TEMPS FALL TO AROUND -2C...BUT
TELECONNECTIONS SUPPORT AN INTRUSION OF COLD AIR ALONG THE EAST
COAST AS THE AO INDEX PLUMMETS TO SHARPLY NEGATIVE VALUES. ALTHOUGH
THE SUN ANGLE IS SLOWLY INCREASING...INSOLATION WILL NOT BE ABLE TO
OVERCOME THE VERY COLD AIR MASS...SO TEMPS MONDAY THROUGH WEDNESDAY
WILL LIKELY REMAIN BELOW CLIMO...COLDEST WEDNESDAY AS A REINFORCING
SHOT OF COLD AIR /DRY FRONT/ CROSSES THE AREA TUESDAY. THE GFS HAS
THIS FRONT STALLING OFFSHORE WED AS A WAVE OF LOW PRESSURE MOVES UP
ALONG IT...BRINGING SLIGHTLY WARMER TEMPERATURES AND INCREASING RAIN
CHANCES. THIS IS AN INDEPENDENT SOLUTION ATTM HOWEVER...AND WILL OPT
TO SHOW CONTINUED DRY WEATHER WITH BELOW NORMAL TEMPS THROUGH
WEDNESDAY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...IFR CONDITIONS WILL BE SETTING UP SHORTLY WITH MAINLY
MVFR/VFR VISIBILITIES. HIGH PRESSURE WILL CONTINUE TO RIDGE JUST
WEST OF THE CWA. THE HRRR MODEL KEEPS ANY PRECIP OFFSHORE AT THIS
TIME...BUT COULD NOT RULE OUT A SPRINKLE AT THE COASTAL TERMINALS
TOWARD MORNING. THURSDAY...A GRADUAL IMPROVEMENT IS FORECAST WITH
CLOUDS SCATTERING IN THE AFTERNOON...ONLY TO RETURN AS STRATUS
SHORTLY AFTER DARK.
EXTENDED OUTLOOK...POTENTIAL FOR MVFR IN SHOWERS FRIDAY
AND EARLY SUNDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...SEA SPECTRUM STILL A BIT UGLY AND A HAZARD
TO SMALL CRAFT...AS HIGH PRESSURE INLAND AND LOW PRESSURE MOVING
NORTH OUT OF THE BAHAMA CHAIN INTERACT TO PRODUCE NNE WINDS 20-25
KT TODAY INTO TONIGHT. SEA HEIGHTS WILL HOLD AT 4-6 FT AND NEAR 7
FT FAR OUTER WATERS WITH DOMINANT PERIODS BETWEEN 6-8 SECONDS.
SEAS MESSY SINCE SE WAVE ENERGY IS CO-MINGLING WITH THE N WAVES.
NO TSTMS ON THE 0-20 NM WATERS BUT A FEW SHOWERS CAN BE EXPECTED
OUTER WATERS MOVING FROM NE TO SW AT 25 KT. ONLY A SLIGHT EASING
OF WIND EXPECTED TONIGHT AS THE LOW OFFSHORE MOVES FARTHER N. SEAS
WILL NEED TIME TO RECOVER AND ITS POSSIBLE THE ADVISORY COULD BE
EXTENDED THIS EVENING OR EVEN OVERNIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WEDGE OF HIGH PRESSURE WILL SLOWLY WEAKEN
INLAND FROM THE WATERS...CAUSING NE WINDS TO SLOWLY FALL OFF
DURING FRIDAY FROM AROUND 15 KTS EARLY TO 10 KTS LATE. WHILE THIS
WILL PERSIST THE PROLONGED NE FETCH...THE FALLING WINDS WILL HELP
SEAS DROP SLOWLY ON FRIDAY. INITIALLY...3-5 FTERS WILL BE COMMON
WITH A FEW 6 FT SEAS STILL POSSIBLE ESPECIALLY ACROSS NC
WATERS...BUT CONFIDENCE NOT HIGH ENOUGH ATTM TO EXTEND SCA INTO
FRIDAY...AND WILL INSTEAD NOTE HERE AND HWO IT MAY BE REQUIRED.
ANY HEADLINES WILL DROP FRIDAY NIGHT AS SEAS FALL TO 3-4 FT.
ON SATURDAY...A WARM FRONT WILL LIFT NORTH ACROSS THE WATERS CAUSING
WINDS TO SHIFT TO THE SE AND THEN TO THE SW LATE SATURDAY.
ACCOMPANYING THIS WIND SHIFT WILL BE A STEADY INCREASE IN SPEED TO
AROUND 20 KTS LATE IN THE DAY AND AT NIGHT. THIS WILL DRIVE WAVE
HEIGHTS ONCE AGAIN UP TO SCA THRESHOLDS OF 4-7 FT...AND RENEWED
HEADLINES ARE LIKELY LATE IN THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUNDAY BEGINS WITH GUSTY SW WINDS AROUND
20 KTS ONGOING ACROSS THE WATERS AHEAD OF A COLD FRONT WHICH WILL
CROSS OFFSHORE SUNDAY EVENING. THESE ENHANCED WINDS WILL CREATE
SEAS OF 4- 7 FT...AND AN SCA WILL LIKELY BE IN EFFECT TO START THE
PERIOD. WITH THE FROPA WILL BE A RAPID WIND SHIFT TO THE NW BUT
WITH SPEEDS REMAINING AT 15-20 KTS SUNDAY NIGHT...BEFORE SLOWLY
FALLING TO AROUND 10 KTS MONDAY WITH A STILL NW DIRECTION.
HEADLINES WILL DROP QUICKLY BEHIND THE FRONT AS THE NW WINDS PUSH
THE HIGHEST SEAS OUT OF THE LOCAL WATERS...AND WAVE HEIGHTS ARE
EXPECTED TO FALL TO 3-5 FT SUNDAY NIGHT...AND THEN FURTHER TO 2-3
FT DURING MONDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC
MARINE...MJC/JDW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
340 AM EST THU JAN 07 2016
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO GRADUALLY WEAKEN
AS IT RETREATS TO THE NORTHEAST THROUGH EARLY THURSDAY.
MEANWHILE...A SERIES OF UPPER DISTURBANCES WILL BEGIN TO CROSS THE
REGION IN SOUTHWESTERLY FLOW ALOFT LATE THIS WEEK...LEADING TO
UNSETTLED WEATHER FOR THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM THURSDAY..
HIGH PRESSURE...MAINTAINED BY SHORTWAVE RIDGING ALOFT...CONTINUES TO
EXTEND FROM THE MID-ATLANTIC STATES THROUGH THE NC PIEDMONT...WITH A
FAIRLY PRONOUNCED INVERTED TROUGH OFFSHORE. ALOFT...THE FLOW IS
GENERALLY WEAK SOUTHWESTERLY WITH DISTURBANCES OFF THE GA/FL COAST
AND OVER THE SOUTHERN PLAINS. A SHALLOW LAYER OF MOISTURE IN
SOUTHEASTERLY FLOW ATOP THE SURFACE RIDGE HAS LED TO WIDESPREAD
STRATUS AND A SMALL AREA OF RECENTLY EXPANDING DRIZZLE JUST EAST OF
THE TRIANGLE AREA...WHICH ITSELF APPEARS TO BE FOCUSED WITHIN THE
REGION OF STRONGEST 925MB WARM ADVECTION. THE MOISTURE IS
SHALLOW...THOUGH SLIGHTLY DEEPER TOWARD THE COAST...AND LUCKILY
DEWPOINTS HAVE RECOVERED INTO THE 30S EVERYWHERE EXCEPT FOR THE FAR
WESTERN PIEDMONT. THIS POORLY RESOLVED AREA OF DRIZZLE SHOULD SHIFT
NORTH-NORTHWESTWARD THIS MORNING AND NOT CAUSE ANY PROBLEMS.
OTHERWISE TODAYS FORECAST CHALLENGE IS WHETHER OR NOT THE STRATUS
WILL PERSIST THROUGH THE DAY. THE 925NMB FLOW SHOULD BACK TO MORE
NORTHEASTERLY THIS MORNING IN RESPONSE TO THE AREA OF LOW PRESSURE
DEVELOPING WELL OFF THE SOUTHEAST COAST...AND THUS THE WARM
ADVECTION WILL DIMINISH. THE NAM AND GFS MAINTAIN THE STRATUS
THROUGH THIS AFTERNOON ON THE EAST WHERE THE MOISTURE IS ALREADY
DEEPER...WHILE BREAKING THE WESTERN PIEDMONT OUT. RAP RUNS HAVE
TENDED TO SCATTER OUT THE ENTIRE AREA. WILL TREND THE FORECAST
TOWARD A LITTLE LESS CLOUD COVER BY THIS AFTERNOON...ADMITTEDLY WITH
LOW CONFIDENCE. HIGHS MAY FEATURE A MORE EVEN DISTRIBUTION THAT
USUAL...WITH MID AND UPPER 40S FOR MOST AREAS. HOWEVER...IF CLOUDS
DO SCATTER THEN LOWER 50S ARE POSSIBLY FOR THE EASTERN HALF OF THE
AREA.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 340 AM THURSDAY...
WHAT MOISTURE IS STILL AROUND THIS EVENING SHOULD LEAD TO
REDEVELOPING STRATUS BENEATH THE INVERSION ALOFT TONIGHT.
MEANWHILE... THE AFOREMENTIONED UPPER DISTURBANCE OVER THE SOUTHERN
PLAINS WILL LIFT TOWARD THE UPPER MIDWEST TONIGHT AND FRIDAY..WHILE
THE EASTERN EXTENT OF THE TROUGH AXIS AND DCVA LIFT ACROSS THE
SOUTHEAST US. THE LEFT EXIT REGION OF THE STJ WILL PROVIDE SOME
UPPER DIVERGENCE...BUT LOW-LEVEL FORCING IS LACKING WITH THE COASTAL
TROUGH STAYING PUT AND PRETTY WEAK LOW-LEVEL FLOW/ADVECTION. THE
TREND IN THE MODELS TOWARD A DRIER FORECAST HAS STABILIZED AND THE
NAM/GFS/ECMWF ALL INDICATED JUST SOME VERY LIGHT SHOWERS DURING THE
DAY ON FRIDAY. WILL MAINTAIN A SLIGHT CHANCE TO CHANCE POP AFTER
12Z FRIDAY AND NO POPS FRIDAY NIGHT AHEAD OF THE NEXT SYSTEM TO
IMPACT THE AREA ON SATURDAY.
LOWS TONIGHT WILL DEPEND HOW MUCH WE SCATTER OUT TODAY AND HOW
QUICKLY CLOUDS INCREASE OVERNIGHT AHEAD OF THE APPROACHING TROUGH.
GIVEN NO CHANGE IN THE AIR MASS AND POTENTIAL FOR OVERCAST
AGAIN...LOWS SHOULD BE SIMILAR TO THIS MORNING...34-42 NW TO SE.
HIGHS FRIDAY COULD BE LOWER WITH MORE PRECIP...BUT WILL STILL
FEATURE A CAD-LIKE RANGE GIVEN THE SURFACE HIGH AND DIABATIC EFFECTS
OF THE LOW CLOUDS...MID 40S NW TO MID 50S SOUTHEAST. AND FINALLY
FRIDAY NIGHT LOWS WILL BE A TAD MILDER IN THE 40-48 RANGE AS
DEWPOINTS CREEP UP INTO THE LOWER 40S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 340 PM WEDNESDAY...
ANOTHER TREND IN THE MODELS IS A FASTER ARRIVAL OF THE NEXT S/W AND
IT`S ASSOC WEATHER...THE S/W THAT`S CURRENTLY POSITIONED JUST
OFFSHORE OF THE PAC NW REGION. RAIN WITH THIS SYSTEM IS NOW PROGGED
BY SAT MORNING PER ECMWF...OR BY SAT EVENING PER GFS. SINCE THE
TREND HAS BEEN EARLIER...AT THIS POINT PREFER THE EARLIER ECWMF
SOLUTION AND HAVE ADJUSTED POPS FOR THAT TIME ACCORDINGLY. WITH THAT
TREND...NOW IT APPEARS THAT SUNDAY (AFTER SUNRISE) WILL BE DRY ON
THE BACK SIDE OF THE AFOREMENTIONED S/W. ALSO IN THE WAKE OF THE
WAVE CAA WILL ENSUE...WITH FORECAST LOW LEVEL THICKNESSES BOTTOMING
OUT BY MONDAY MORNING AND REMAINING IN THE 1290-1305M RANGE THROUGH
MIDWEEK...WHICH IS ABOUT NORMAL FOR THIS TIME OF YEAR AND TYPICALLY
RESULTS IN HIGHS IN THE M-U 40S AND LOWS AROUND 30.
OTHERWISE...YET ANOTHER MODEL CHANGE IS THAT THE LATEST GFS BRINGS
MOISTURE AND SOUTHERN STREAM S/W ENERGY UP ACROSS THE COASTAL SE
STATES...WITH A RESULTANT COASTAL LOW PROGGED TO LIFT NE ALONG THE
GULF STREAM ON TUESDAY. THE 12Z ECMWF...SIMILAR TO ITS PREV RUNS...
STILL KEEPS THE S/W ENERGY FLATTER AND FARTHER SUPPRESSED TO THE
SOUTH...WITH THE END RESULT BEING A CONTINUATION OF DRY SEASONABLE
WEATHER FOR THE MON-WED TIME FRAME. THE VAST MAJORITY OF THE ECMWF
ENSEMBLE MEMBERS SUPPORT THE DRY OPERATIONAL SOLUTION...AND IT SEEMS
WISE TO NOT JUMP ON ONE RUN OF THE GFS...WHICH HAS BEEN A BIG CHANGE
FROM PREV RUNS...SO FOR NOW WILL KEEP THE MON-WED TIME FRAME DRY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 100 AM THURSDAY...
SOUTH-SOUTHEASTERLY FLOW JUST ABOVE THE SURFACE HAS ADVECTED A
SHALLOW LAYER OF MOISTURE ACROSS CENTRAL NC...WITH MVFR CEILINGS NOW
BLANKETING THE AREA. THE MOISTURE IS A LITTLE DEEPER OVER THE
COASTAL PLAIN...WHERE A PERIOD OF IFR CEILINGS IS POSSIBLE PRIOR TO
12Z...AND THEN MVFR CEILINGS ARE MOST LIKELY TO PERSIST THROUGH THE
DAY. TO THE WEST AT KGSO AND KINT...WHERE THE MOISTURE IS MUCH MORE
SHALLOW...MODELS SHOW A BETTER CHANCE OF THE CEILINGS BREAKING BY
MIDDAY. MODELS HAVE STRUGGLED WITH THIS SHALLOW MOISTURE..SO
CONFIDENCE IS BELOW AVERAGE AT THIS POINT.
OUTLOOK...A COUPLE OF LOW PRESSURE SYSTEMS WILL IMPACT THE REGION
THROUGH THE WEEKEND. DESPITE VERY LITTLE RAIN WILL THE FIRST
SYSTEM ON FRIDAY...MVFR/IFR CEILINGS ARE EXPECTED...CONTINUING
THROUGH SATURDAY AS A STRONGER SYSTEM BRING WIDESPREAD RAIN.
IMPROVING CONDITIONS ARE EXPECTED BY SUNDAY AND MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...22
SHORT TERM...22
LONG TERM...RAH
AVIATION...22
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1250 AM EST THU JAN 7 2016
.SYNOPSIS...
HIGH PRESSURE WILL PUSH DOWN THE COAST THROUGH FRIDAY WHILE A
COASTAL FRONT LINGERS OFFSHORE. A GRADUAL WARMING TREND WILL BEGIN
FRIDAY AS THE WEDGE OF HIGH PRESSURE BREAKS DOWN...BUT THIS WILL
BRING A CHANCE FOR RAIN ON FRIDAY. A WARM FRONT WILL LIFT NORTH
ACROSS THE AREA BRINGING A BETTER CHANCE FOR SHOWERS DURING THE
WEEKEND. MUCH COOLER TEMPERATURES WILL FOLLOW A COLD FRONT EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1250 AM THURSDAY...ADDED MENTION OF PATCHY DRIZZLE AS IT IS
POSSIBLE THAT WEAK ISENTROPIC LIFT OVER SHALLOW COOL LAYER COULD
WRING OUT SOME VERY LIGHT PRECIPITATION AS CEILINGS LOWER.
INCLUDED MENTION OF PATCHY DRIZZLE THROUGHOUT GIVEN LATEST MODEL
SOUNDINGS DO SUPPORT A PRONOUNCED NEAR SURFACE INVERSION WITH ONLY
THE LOWEST 5 TO 8 HUNDRED FT DRYING OUT. KEPT POPS BELOW THRESHOLD
AS MEASURABLE RAINFALL IS NOT EXPECTED TO MAKE IT ONSHORE.
LIGHT RAIN CONTINUED TO SLIDE DOWN THE CAROLINA AND SOUTHEAST
COAST ALONG A NEARLY STATIONARY FRONT...DEMARCATING A ZONE OF
LOW-LEVEL CONVERGENCE. THIS FRONT IS NOT EXPECTED TO MOVE THAT
MUCH OVERNIGHT AND CONSEQUENTLY...THE RAIN SHOULD REMAIN OFFSHORE.
STRENGTHENING LOW PRESSURE...ABOUT 500 MILES SSE OF THE MOUTH OF
THE CAPE FEAR RIVER...IS EXPECTED TO MOVE NNE...PASSING WELL
OFFSHORE OF THE CAROLINAS THROUGH FRIDAY.
A COASTAL FRONT CONTINUES TO SHARPEN OFFSHORE AS A WEDGE OF HIGH
PRESSURE REMAINS IN PLACE ACROSS THE WESTERN CAROLINAS. THE
MOISTURE PROFILES SHOW VERY DRY AIR ABOVE 7-9 KFT AND DRY AIR
NEAR THE SURFACE. PRECIPITABLE WATER VALUES ONLY RISE MARGINALLY
THROUGH THU MORNING. ALTHOUGH SPOTTY DRIZZLE CAN NOT BE RULED
OUT...MEASURABLE RAINFALL SHOULD BE HARD TO COME BY AND SO HAVE
KEPT POPS NEAR OR BELOW THRESHOLD AT THE COAST AND MUCH LOWER AS
YOU PROGRESS INLAND.
AN ABUNDANCE OF CLOUDS AND AN ONSHORE FLOW SHOULD KEEP TEMPS MUCH
HIGHER THAN IN RECENT NIGHTS. WE DO NOT EXPECT LOW TEMPS BELOW
THE UPPER 30S AND LOWER 40S. A FEW SPOTS ALONG AND WEST OF
INTERSTATE 95 MAY DROP TO THE MID 30S. ALL AREAS WILL REMAIN ABOVE
FREEZING TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...MID LEVEL RIDGING WILL DEVELOP INTO
BASICALLY A SOUTHWEST FLOW THROUGH THE PERIOD. THERE IS ONE
SUBTLE SHORTWAVE MOVING ACROSS LATE FRIDAY WHICH MAY KICK OFF A
FEW SHOWERS. AT THE SURFACE HIGH PRESSURE WILL CONTINUE TO WEDGE
DOWN INTO THE AREA THROUGH THE PERIOD ALTHOUGH THE AIRMASS WILL
SLOWLY MODIFY. I HAVE WALKED BACK POPS ESSENTIALLY THROUGH THE
PERIOD. ANY ACTIVITY SNEAKING IN FROM OFFSHORE WITH THE COASTAL
FRONT SEEMS A STRETCH. THE FORCING AND MOISTURE WITH THE SHORTWAVE
FRIDAY LOOK RATHER TEPID AS WELL. TEMPERATURE GUIDANCE IN TWO
DISTINCT CAMPS WITH THE MET NUMBERS MUCH COOLER ACROSS THE BOARD.
LEANED HEAVILY TOWARD THE WARMER MAV ALTHOUGH THE SLOW MODERATION
TODAY GIVES ME A LITTLE HESITATION.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...WE WILL HAVE TWO MAIN AIRMASSES TO CONTEND
WITH THROUGH THE LONG TERM. THE FIRST WILL BE WARM AND MOISTURE-
LADEN ON SATURDAY ESPECIALLY FOLLOWING THE AFTERNOON PASSAGE OF A
WARM FRONT AHEAD OF DEVELOPING LOW EAST OF THE SOUTHERN FRINGE OF
THE APPALACHIANS. DESPITE WIDESPREAD CLOUD COVER AND PERHAPS
INTERMITTENT LIGHT RAIN SATURDAY WILL WARM UP INTO THE 60S. LOW
LEVEL JET AND WARM TONGUE RUN UP THE COAST SATURDAY NIGHT FOR NOT
ONLY A POSSIBLE INCREASE IN RAIN CHANCES BUT PERHAPS ALSO A FEW
STRONG GUSTY SHOWERS. ASCENT MAY BE TOO WEAK/SHALLOW FOR DEEP
CONVECTION/LIGHTNING FOR MUCH OF THE NIGHT SAVE FOR MAYBE ACTUAL
FROPA IN THE 10-12Z SUNDAY TIME FRAME . STRONG CAA ON SUNDAY
POSSIBLY MAKING FOR A NON-DIURNAL CURVE AND THUS NAILING THE ACTUAL
HIGH TEMPERATURE A BIT TRICKY. THE REST OF THE LONG TERM WILL BRING
A CONTINUATION OF COOL AND DRY ADVECTION THOUGH NOT WITH THE
STRENGTH SEEN ON SUNDAY. EVEN SO THE PERSISTENCE OF THE ADVECTION
MAY WIN OUT OVER SOLAR MODIFICATION FOR A GRADUAL DOWNWARD TREND IN
TEMPERATURES TOWARDS CLIMATOLOGY OR A LITTLE BELOW BY THE PERIOD`S
END.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...IFR CONDITIONS WILL BE SETTING UP SHORTLY WITH MAINLY
MVFR/VFR VISIBILITIES. HIGH PRESSURE WILL CONTINUE TO RIDGE JUST
WEST OF THE CWA. THE HRRR MODEL KEEPS ANY PRECIP OFFSHORE AT THIS
TIME...BUT COULD NOT RULE OUT A SPRINKLE AT THE COASTAL TERMINALS
TOWARD MORNING. THURSDAY...A GRADUAL IMPROVEMENT IS FORECAST WITH
CLOUDS SCATTERING IN THE AFTERNOON...ONLY TO RETURN AS STRATUS
SHORTLY AFTER DARK.
EXTENDED OUTLOOK...POTENTIAL FOR MVFR IN SHOWERS FRIDAY
AND EARLY SUNDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 AM THURSDAY...A SMALL CRAFT ADVISORY IS IN EFFECT FOR
ALL WATERS INTO THU. A TIGHT PRESSURE GRADIENT WILL REMAIN ACROSS
THE WATERS WITH A WEDGE OF HIGH PRESSURE HOLDING ACROSS THE
WESTERN CAROLINAS AS LOW PRESSURE MOVES NE...BUT REMAINS OFFSHORE
AS IT PARALLELS THE SOUTHEAST COAST THROUGH THU. THE WIND
DIRECTION WILL REMAIN NNE TO NE AT SPEEDS OF 20 TO 30 KT. SEAS
WILL BE IN THE RANGE OF 5 TO 8 FT ACROSS THE OUTER WATERS. AS YOU
MOVE INTO LONG BAY...SEAS WILL BE CONSIDERABLY LOWER GIVEN THE
SEVERE FETCH RESTRICTIONS ON A NORTHERLY FLOW.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...NORTHEAST WINDS WILL PREVAIL ACROSS THE WATERS
THROUGH THE PERIOD. HOWEVER THE GRADIENT DOES WEAKEN AND SPEEDS GO
FROM 15-20 KNOTS THURSDAY TO TEN KNOTS OR LESS BY SATURDAY MORNING.
SMALL CRAFT SEAS WILL CONTINUE THURSDAY BUT BECOME MORE MARGINAL FOR
THE REMAINDER OF THE PERIOD. STILL A SIX FOOTER OR TWO SHOWING UP
FOR THURSDAY NIGHT INTO FRIDAY SO SOME FINE TUNING WILL BE IN ORDER
TO DETERMINE THE NATURE OF HEADLINES.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...WIND GOES FROM EASTERLY/ONSHORE TO SOUTHERLY
ON SATURDAY WITH THE PASSAGE OF A WARM FRONT. THE INCREASE IN
SOUTHWESTERLY PRE COLD-FRONTAL FLOW WILL BE DELAYED UNTIL LATE
SATURDAY AND THEN MORESO SATURDAY NIGHT AS A FAIRLY STRONG COLD
FRONT IMPINGES UPON THE AREA. SEAS MAY BRIEFLY BUILD TO ADVISORY-
WORTHY 6 FT WELL AWAY FROM SHORE. THE REMAINDER OF SUNDAY WILL
FEATURE SOME FRESH OFFSHORE FLOW BUT LIKELY NOT TO WHERE ADVISORY
WILL BE MAINTAINED THOUGH SCEC IS TOUGH TO RULE OUT. HIGH PRESSURE
BUILDING IN FROM THE NORTHWEST ON MONDAY VEERS WINDS TO THE NORTH
WHILE WIND AND SEAS REMAIN NEAR SCEC HEADLINE VALUES ESPECIALLY OVER
NORTHERN WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ250-252-254-
256.
&&
$$
NEAR TERM...RJD/MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...DL/MJC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
349 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
WHAT HAPPENS WITH THE MESOSCALE SNOW BAND AND WHAT TO DO WITH
HEADLINES WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM.
WEAK SHORTWAVE TROUGH MOVING THROUGH ND...WITH A SFC LOW OVER
NORTH CENTRAL SD. THE MESOSCALE SNOW BAND OVER THE SOUTHERN RED
RIVER VALLEY HAS CONTINUED TO SLOWLY MOVE SOUTHEAST. THE
MID LEVEL FRONTOGENESIS DOES NOT LOOK ALL THAT STRONG WHERE THE
BAND IS LOCATED...BUT WITH NEGATIVE EPV AND HIGH MID LEVEL LAPSE
RATES THERE HAS BEEN ENOUGH INSTABILITY TO GET A NARROW AREA OF
HEAVY SNOW. WHERE THE BEST FRONTOGENSIS IS LOCATED OVER THE
NORTHWESTERN CWA A BAND TRIED TO GET GOING...BUT SEEMS TO BE
DISSIPATING LAST FEW SCANS. THERE HAS BEEN A REPORT OF 6 PLUS
INCHES IN CASSELTON SO THE WARNING SEEMS TO BE ON TRACK. THE HOP
WRF...RAP...AND HRRR ALL HAVE A NARROW BAND OF HIGH SNOW
ACCUMULATION EXTENDING FROM CENTRAL CASS COUNTY UP INTO THE
CLAY/NORMAN AREA. THERE ARE HINTS THAT THE HEAVY SNOW COULD EXTEND
FURTHER NORTHEAST...AND THERE HAS BEEN SOME FAIRLY HEAVY RADAR
RETURNS IN NORTHEASTERN MAHNOMEN COUNTY CURRENTLY. GIVEN THAT THE
EPV AND LAPSE RATES SLOWLY BECOME A BIT LESS FAVORABLE GOING INTO
TODAY...AM NOT SURE HOW LONG THE BAND WILL BE PRODUCING 2 PLUS PER
HOUR SNOWFALL RATES. HAVE THE HEAVY SNOW BAND IN THE GRIDS
EXTENDING INTO THE FAR CORNER OF MAHNOMEN...BUT WILL KEEP THE
HEADLINES AS THEY ARE FOR NOW AND REEVALUATE WHEN WE GET A BIT
MORE GROUND TRUTH LATER THIS MORNING.
THE OTHER ISSUE WILL BE FREEZING DRIZZLE. THE PKD ASOS CONTINUES
TO REPORT AN I GROUP AT TIMES...AND MODEL SOUNDING ACROSS MUCH OF
THE CWA SHOW A DRY LAYER ALOFT EXCEPT WHEN THE SNOW BAND IS
GOING THROUGH. WILL CONTINUE TO KEEP A FREEZING DRIZZLE MENTION
THROUGH THE REST OF THE MORNING AND WILL KEEP THE ADVISORY GOING
IN THE SOUTH FOR THAT REASON. THERE ARE SOME SIGNS OF DRIER AIR
ALOFT COMING IN TONIGHT...PARTICULARLY IN THE WESTERN COUNTIES AS
COLDER AIR COMES DOWN THE BACKSIDE OF THE SFC LOW. WILL INCLUDE A
SLIGHT CHANCE OF FREEZING DRIZZLE MENTION FOR TONIGHT...FOLLOWING
WHERE THE MODELS HAVE THE LOWER CHANCES OF ICE CRYSTALS IN THE
CLOUD.
LIGHT SNOW WILL ALSO CONTINUE AT TIMES AS THE MAIN UPPER
TROUGH DIGS DOWN OUT OF CANADA ON FRIDAY. DO NOT THINK THERE WILL
BE VERY MUCH ACCUMULATION...BUT KEPT SOME CHANCE POPS FOR UP TO
HALF AN INCH OF ACCUMULATION. THE ARCTIC AIR WILL START BUILDING
DOWN INTO THE NORTHERN PLAINS FRIDAY. MODELS HAVE 925MB
TEMPERATURES DOWN TO -20 C BY LATE AFTERNOON. THINK THAT READINGS
WILL FALL THROUGHOUT THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
FRIDAY NIGHT THROUGH SATURDAY NIGHT...ARCTIC HIGH PRESSURE PARKS
ITSELF OVER THE NORTHERN PLAINS. THINK THAT THERE MAY BE A BIT OF
LIGHT SNOW LINGERING OVER THE NORTHEAST INTO FRIDAY NIGHT...BUT
OTHERWISE THERE WILL BE CLEARING OUT AND COLD THROUGH THE PERIOD.
TEMPS WILL BE BELOW ZERO EVEN INTO SATURDAY AFTERNOON...AND COULD
DROP DOWN TO THE 15 TO 20 BELOW RANGE SATURDAY NIGHT. WIND CHILLS
WILL ALSO MAKE IT SEEM EVEN COLDER.
SUNDAY-WEDNESDAY...BELOW AVE TEMPS WILL CONTINUE TO BE THE THEME
DURING THIS TIME. ANOTHER COLD DAY IS EXPECTED FOR SUNDAY...EVEN AS
THE COLDEST 850 MB TEMPS SHIFT EAST AND THE SFC HIGH DROPS SOUTH OF
REGION. THE NEXT ARCTIC FRONT LOOKS TO SWEEP THROUGH AROUND
MONDAY...REINFORCING THE COLD AIR THROUGH THE EARLY PART OF THE
WEEK. CURRENTLY HAVE THE EARLY WEEK PERIOD DRY...BUT THE 00Z
GFS/ECMWF DO SHOW A CLIPPER SYSTEM MOVING SOUTH WITH THE ARCTIC AIR
MONDAY...WITH SOME POTENTIAL FOR LIGHT SNOW. SOME MODERATION IN
TEMPS IS POSSIBLE BY MID-WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1143 PM CST WED JAN 6 2016
TRIED TO TIME THE HEAVY SNOW BAND AS BEST POSSIBLE...MAINLY
AFFECTING KFAR/KBJI. LOOKS LIKE IT SHOULD MOVE OUT DURING
THURSDAY MORNING...LEAVING VERY LIGHT SNOW OR FLURRIES AROUND.
LEFT THE LOW CEILINGS IN PLACE THOUGH. WINDS WILL STAY ON THE
LIGHTER SIDE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ028-
029-038-049-052-053.
WINTER STORM WARNING UNTIL 9 AM CST THIS MORNING FOR NDZ030-039.
MN...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ001-
009-013>017-022>024-027>032-040.
WINTER STORM WARNING UNTIL 9 AM CST THIS MORNING FOR MNZ002-003.
&&
$$
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...GODON
AREA FORECAST DISCUSSION
NWS PORTLAND OR
936 PM PST WED JAN 6 2016
.SYNOPSIS...A BROAD COMPLEX LOW WILL REMAIN OFF THE COAST TONIGHT AND
THURSDAY BEFORE MOVING SOUTHEAST AND WEAKENING BY FRIDAY. THIS
FEATURE MAY SPREAD SOME LIGHT PRECIPITATION INTO NORTHWEST OREGON AND
SOUTHWEST WASHINGTON AT TIMES INTO THURSDAY...BUT THERE WILL ALSO BE
CONSIDERABLE DRY PERIODS. COOL OFFSHORE FLOW WILL CONTINUE AS WELL.
ADDITIONAL LIGHT ICING MAY OCCUR AROUND THE COLUMBIA RIVER GORGE.
FRIDAY IS LOOKING GENERALLY DRY. ANOTHER SYSTEM HEADING TOWARD
NORTHERN CALIFORNIA WILL MORE THAN LIKELY SPREAD SOME MOISTURE
NORTHWARD AGAIN INTO OUR FORECAST AREA LATE FRIDAY NIGHT THROUGH
SATURDAY THAT COULD RESULT IN ANOTHER WINTER MIX OF PRECIPITATION
INLAND...POSSIBLY LINGERING INTO EARLY SUNDAY. THE NEXT SYSTEM IS NOT
EXPECTED UNTIL THE EARLY OR MIDDLE PART OF NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH SATURDAY...A BROAD AREA OF LOW PRES
CURRENTLY STRETCHES FROM THE BRITISH COLUMBIA COAST DOWN ALONG MOST
OF THE U.S. WEST COAST. OUT AHEAD OF THE MAIN TROUGH AXIS...THERE IS
A BAND OF INCREASED MOISTURE AND LIGHT PRECIPITATION DRAPED OVER THE
CENTRAL AND SOUTHERN WILLAMETTE VALLEY INTO THE LANE COUNTY CASCADES
THIS EVENING. THIS BAND APPEARS TO BE THE REMAINS OF AN OLD OCCLUDED
FRONT...AND MAY BE GETTING SOME ADDITIONAL ENHANCEMENT FROM A WEAK
DEFORMATION ZONE. THE FCST MODELS SEEM TO HAVE KEYED IN ON THIS
FEATURE REASONABLY WELL...PARTICULARLY THE 04Z RUN OF THE HRRR MODEL.
BASED ON THE LATEST MODEL TRENDS...EXPECT THIS BAND TO SLOWLY LIFT
NORTH LATER THIS EVENING AND OVERNIGHT...BEFORE DISSIPATING EARLY THU
MORNING OVER FAR NW OREGON. EXPECT LITTLE TO NO PRECIPITATION
FURTHER NORTH OVER OUR SW WASHINGTON ZONES. TEMPERATURES REMAIN IN
THE 35 TO 40 DEG F AT CURRENT THROUGH MOST OF THE REGION...WITH DEW
POINTS ABOVE 32 DEG AS WELL. THERE IS ALSO QUITE A BIT OF CLOUD COVER
OVER THE REGION TO PREVENT EXTENSIVE RADIATIONAL COOLING. SO
PRECIPITATION SHOULD FALL AS LIGHT RAIN FOR MOST LOCATIONS TONIGHT.
HOWEVER...EAST WINDS CONTINUE THROUGH THE GORGE AND LOCATIONS AROUND
THE WEST END OF THE GORGE MAY POTENTIALLY SEE SOME ADDITIONAL LIGHT
ICING. PRECIPITATION LIKELY TO REMAIN SNOW IN THE CENTRAL GORGE AND
UPPER HOOD RIVER VALLEY. VERY LIGHT PRECIPITATION MAY CONTINUE AT
TIMES THROUGH THU NIGHT.
THE OFFSHORE LOW IS FORECAST TO SHEAR OUT TO THE SOUTH OF OUR AREA BY
FRIDAY...AND OUR FORECAST AREA SHOULD BE MOSTLY DRY THEN. EAST WINDS
ARE FORECAST BY ALL OF THE MODELS TO EASE UP THURSDAY AND FRIDAY AS
WELL. AREAS OF FOG THURSDAY NIGHT AND FRIDAY MIGHT BE A BIT SLOW TO
CLEAR OUT FRIDAY AFTERNOON UNDER THE WEAK SURFACE GRADIENTS.
ATTENTION THEN TURNS TO THE NEXT SYSTEM. THE MODELS APPEAR TO FINALLY
BE CONVERGING ON A SOLUTION FOR LATER FRIDAY NIGHT AND SATURDAY.
WHILE THE BULK OF THE ENERGY WITH THIS NEXT SYSTEM IS HEADED TOWARD
CALIFORNIA...SOME OF THE MOISTURE IS FORECAST TO SPREAD NORTH AS A
DEFORMATION ZONE LATE FRIDAY NIGHT AND ESPECIALLY ON SATURDAY. THE
MODELS ARE TRENDING TOWARD LIQUID EQUIVALENT PRECIPITATION AMOUNTS
CLOSE TO THOSE THIS PAST SUNDAY. THE MODELS ARE ALSO SHOWING
INCREASING EAST WINDS AS THE ASSOCIATED DECENTLY DEEP SURFACE LOW
APPROACHES THE OREGON COAST. THIS WILL SET THE STAGE FOR A WINTRY MIX
OF PRECIPITATION INLAND AGAIN. IT IS A BIT EARLY TO BE TOO CONFIDENT
ON THE DETAILS YET...BUT THERE IS A RISK OF SOME TRAVEL DISRUPTIONS
AGAIN. IF THE LOW MOVES NORTH ALONG THE COAST BY LATER SATURDAY AND
SATURDAY NIGHT...THERE COULD BE SOME MODERATING SOUTHERLY WINDS
MOVING UP THE VALLEY...THOUGH AREAS NEAR THE GORGE MAY BE VERY SLOW
TO CHANGE MUCH. PYLE/TOLLESON
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY...IT APPEARS THE
SATURDAY SYSTEM SHOULD MOVE AWAY SUNDAY FOR DRYING. AFTER A BRIEF
UPPER RIDGE...THE NEXT SYSTEM IS EXPECTED EARLY NEXT WEEK. THE FASTER
GFS MAY BE A BIT TOO FAST...AND CURRENTLY BLENDED TOWARD THE SLOWER
ECMWF. WILL HAVE TO MONITOR PRECIPITATION TYPE AS WE GET CLOSER TO
THE SYSTEMS NEXT WEEK AS THAT IS UNCLEAR AT THE MOMENT. TOLLESON
&&
.AVIATION...PRIMARILY VFR CONDITIONS EXPECTED TONIGHT WITH LOCAL
MVFR TO IFR CONDITIONS IN FOG/STRATUS FOR THE LOWER COLUMBIA RIVER
AND SOUTH WILLAMETTE VALLEY. LIGHT PRECIPITATION EXPECTED AS IMPULSES
CONTINUE TO ROTATE AROUND A BROAD ERN PAC LOW THROUGH THU MIDDAY.
MAIN FORECAST CHALLENGE WILL BE THE EXTENT OF VALLEY IFR/LIFR
COVERAGE TONIGHT THROUGH THU MORNING. SATELLITE IMAGERY SHOWS
CONSIDERABLE MID AND HIGH LEVEL CLOUDS MOVING INTO THE FORECAST
AREA...WHICH WOULD TEND TO INHIBIT OR REDUCE STRATUS AND FOG
FORMATION. MAY SEE SOME SCT-BKN CLOUD DECK DEPICTED BY GFS AND
NAM 13Z-20Z THU.
KPDX AND APPROACHES...VFR PREVAILING WITH INTERMITTENT LIGHT RAIN
THROUGH THU MORNING. EXPECT AREAS OF IFR/LIFR ALONG WRN
APPROACHES THROUGH THU MORNING. WEISHAAR /MH
&&
.MARINE...WIND SPEEDS CONTINUE TO DIMINISH THIS EVENING...BUT NEW
MODELS SHOW STRONGER WINDS OVER THE OUTER WATERS THU. SO HAVE
INCREASED WINDS BUT KEPT IT BELOW ADVISORY CRITERIA FOR NOW.
OFFSHORE GRADIENT INCREASES FRI THROUGH SAT AND HAVE INCREASED
WIND SPEEDS TO 15-20 KT. MODELS STARTING TO COME MORE IN LINE
DEVELOPING A 1004MB LOW OFF THE S OREGON COAST 12Z SAT. THIS
SHOULD PRODUCE SMALL CRAFT ADVISORY WIND SAT. ANOTHER ROUND OF
INCREASED WIND IS EXPECTED EARLY NEXT WEEK...POSSIBLY RESULTING IN
GALE FORCE WIND GUSTS.
HAVE EXTENDED THE SMALL CRAFT ADVISORY FOR SEAS THROUGH 00Z
FRI. SEAS WILL CONTINUE TO SUBSIDE A BIT THROUGH THIS EVENING...BUT
THEN BUILD TO 13 TO 16 FT RANGE OVERNIGHT INTO THU MORNING. LATEST
GUIDANCE SHOWS SEAS OF 15-20 FT EARLY NEXT WEEK. HAVE GONE
SLIGHTLY UNDER THE ENP GUIDANCE FOR NOW. WEISHAAR /MH
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM
PST THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR
UNTIL 4 PM PST THURSDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS SEATTLE WA
840 PM PST WED JAN 6 2016
.SYNOPSIS...A WEAKENING UPPER LOW IN THE SOUTHERN WASHINGTON
OFFSHORE WATERS WILL SLIDE SOUTHEAST INTO OREGON LATE THURSDAY AS IT
DISSIPATES. AN UPPER HIGH OVER THE YUKON WILL MERGE WITH A RIDGE
WELL OFFSHORE THEN SHIFT EAST ACROSS THE AREA ON FRIDAY NIGHT.
ANOTHER LOW WILL MOVE BY WELL TO THE SOUTH OF THE AREA OVER THE
WEEKEND.
&&
.SHORT TERM...A RATHER TYPICAL EL NINO JANUARY PATTERN APPEARS TO BE
TAKING HOLD ACROSS THE WEST. A STRONG JET STREAM IS AIMED IN AT FAR
SOUTHERN CALIFORNIA TAKING STORMS INLAND WELL SOUTH OF OUR AREA.
WESTERN WASHINGTON WILL BE DOMINATED BY A COMBINATION OF WEAK AND
DISSIPATING SPLITTING SYSTEMS AND UPPER RIDGES.
THE FIRST OLD UPPER LOW IS CENTERED NEAR 47N 131W THIS EVENING. IT
WILL WOBBLE AROUND TONIGHT THEN DISSIPATE AS IT MOVES INTO WEST
CENTRAL OREGON ON THURSDAY. CLOUDS WRAPPING AROUND THIS CIRCULATION
EXTEND NORTHWARD TO AROUND A SEATTLE-FORKS LINE. THE PRESENCE OF
THESE CLOUDS DOES NOT APPEAR TO BE INHIBITING FOG FORMATION MUCH
THIS EVENING WITH TACOMA...SHELTON...OLYMPIA...AND CHEHALIS ALL
FOGGED IN AT 8 PM. FOG IS ALSO BEING REPORTED AT PORT TOWNSEND AND
SHOULD BE FORMING IN TYPICALLY FOGGY VALLEY LOCATIONS EAST OF
INTERSTATE 5 FROM ABOUT ARLINGTON SOUTHWARD BY MIDNIGHT. AN UPDATE
FOR AREAS OF FOG TONIGHT AND PATCHY FOG THURSDAY MORNING ACROSS
PORTIONS OF THE INTERIOR WAS ISSUED EARLIER. WHILE TEMPERATURES HAVE
ALREADY COOLED TO NEAR THEIR FORECAST LOW VALUES IN THE SOUTH
INTERIOR...FOG AND CLOUDS SHOULD INBIBIT ADDITIONAL COOLING.
CLOUDS WILL WRAP AROUND THE OFFSHORE LOW ON THURSDAY RESULTING IN A
MOSTLY CLOUDY DAY OVER THE SOUTHERN HALF OF THE FORECAST AREA. WITH
THE ADDED CLOUD COVER...EXPECT IT TO BE COOLER WITH HIGHS IN THE
LOWER TO MID 40S...INSTEAD OF THE INCREDIBLE SPRING-LIKE LOWER TO
MID 50S WE SAW TODAY IN THE SEATTLE AREA.
A WEAK UPPER LEVEL RIDGE WILL SHIFT INLAND THURSDAY NIGHT INTO
FRIDAY FOR DRY AND STABLE CONDITIONS. IT CONTINUES TO APPEAR THAT WE
WILL SEE SOME CLEARING FRIDAY AFTERNOON. ANOTHER WEAK UPPER LEVEL
LOW WILL MOVE INLAND AROUND THE SOUTH OREGON COAST SATURDAY
AFTERNOON. MOISTURE WRAPPING AROUND THIS LOW WILL MOVE NORTHWARD
INTO FAR SOUTHERN WASHINGTON SATURDAY AFTERNOON...BUT IT APPEARS
THAT THE FORECAST AREA SHOULD REMAIN DRY WITH ONLY OCCASIONAL MID
AND HIGH LEVEL CLOUDS.
AS MENTIONED EARLIER...A SHORT TERM UPDATE WAS ISSUED TO INCREASE
THE AREAL COVERAGE AND EXTENT OF FOG TONIGHT AND THURSDAY MORNING.
OTHERWISE THE FORECAST IS ON TRACK AND NO FURTHER UPDATES ARE
EXPECTED. ALBRECHT
.LONG TERM...FROM THE PREVIOUS LONG TERM DISCUSSION...AN UPPER LEVEL
RIDGE WILL KEEP THE WEATHER OVER WESTERN WA DRY THROUGH THE REST OF
THE WEEKEND. THE RIDGE MAY BREAK DOWN MONDAY NIGHT OR TUESDAY AS A
TROUGH ARRIVES. WEAK SYSTEMS WILL BRING A CHANCE OF RAIN THROUGH THE
END OF THE WEEK. TEMPERATURES ARE NEAR NORMAL THROUGH THE PERIOD. 33
&&
.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED FOR THE NEXT 7 DAYS.
&&
.AVIATION...UNDER A RELATIVE AREA OF HIGH PRESSURE ALOFT...BUT IT IS
MORE OF A COL BETWEEN AN UPPER TROUGH OVER THE CANADIAN PROVINCES
AND AN UPPER TROUGH OFF THE WEST COAST OF NORTH AMERICA.
AS A RESULT...LIGHT AND VARIABLE FLOW ALOFT. EASING OF EASTERLY
SURFACE WINDS WILL HELP THE AIR MASS MOISTEN A BIT OVER THE NEXT 24
HOURS. PLENTY OF DENSE FOG OBS OVER THE SOUTH SOUND AND SW INTERIOR
RIGHT NOW. MID-LEVEL CLOUDS WILL INHIBIT EXPANSION OF THE FOG...BUT
ANY BREAKS IN THE MID-LEVEL CLOUDS WILL ALLOW EXPANSION.
KSEA...GROWING CONCERNED ABOUT FOG AT THE TERMINAL FROM OVERNIGHT
TONIGHT THROUGH THU MORNING. AREAS OF FOG ARE CURRENTLY OBSERVED
AROUND TIW/TCM. DRYING EASTERLY WINDS AT THE TERMINAL HAVE JUST
ENDED...AND MOST GUIDANCE SHOWS A LIGHT SOUTH BREEZE DEVELOPING
AROUND 08Z-09Z. THIS COULD BRING FOG UP FROM THE SOUTH OVERNIGHT.
IN FACT...THE HRRR MODEL EXPLICITLY SHOWS DENSE FOG OVERSPREADING
KSEA AROUND 08Z-10Z...PERSISTING INTO THE MORNING. THE NEXT TAF
ISSUANCE AT 06Z WILL HIT THE FOG SCENARIO HARDER. FOG WOULD BE
FAIRLY SHALLOW...BUT MID-LEVEL CLOUDS MAY HELP ANY FOG PERSIST UNTIL
20Z OR SO.HANER
&&
.MARINE...A SURFACE LOW ABOUT 350 NM W OF ASTORIA THIS EVENING WILL
WEAKEN AND MOVE SLOWLY SE LATE TONIGHT AND THU...ALLOWING OFFSHORE
FLOW TO WEAKEN. THAT LOW WILL EVENTUALLY DISSIPATE THURSDAY NIGHT
OFF THE S OREGON COAST. OFFSHORE FLOW WILL RE-STRENGTHEN A BIT ON
FRI NGT AND SAT. THIS WILL PROBABLY RESULT IN SCA WINDS AT THE WEST
ENTRANCE. THE MUCH WEAKENED FRONT WILL MOVE OVER THE WA COASTAL AND
OFFSHORE WATERS SATURDAY NIGHT AND SUNDAY.
OFFSHORE FLOW WILL CONTINUE INTO NEXT WEEK. OTHERWISE...OCEAN SWELL
OF 10-13 FEET WILL CONTINUE UNTIL THU EVNG...THEN SUBSIDE BELOW 10
FT.HANER
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST THURSDAY
FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO
60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT
10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE
10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO
CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER OUT 10 NM.
SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 4 AM PST FRIDAY FOR
GRAYS HARBOR BAR.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CST WED JAN 6 2016
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 301 PM CST WED JAN 6 2016
MESSY WINTER WEATHER TO IMPACT THE AREA THROUGH THE PERIOD.
WATER VAPOR IMAGERY SHOWING A VIGOROUS MID-LEVEL TROUGH/CLOSED LOW
OVER WESTERN IA. RADAR MOSAIC SHOWING PRECIPITATION EXPANDING AHEAD
OF THIS WAVE FROM SOUTHERN MN INTO IA AND SOUTHERN WI. GROUND
OBSERVATIONS SHOWING MAINLY A MIXTURE OF DRIZZLE/SNOW ACROSS THAT
AREA.
WILL BE WATCHING THAT MID-LEVEL LOW LIFT NORTHEAST INTO/THROUGH THE
AREA TONIGHT WHILE WEAKENING/DAMPENING OUT. RAP SHOWS THAT THE P-
TYPE SHOULD BE MAINLY IN THE FORM OF LIGHT SNOW WITH INCREASING
COLUMN SATURATION WITH ICE PRESENT IN CLOUD. HOWEVER...THINGS
COULD GET TRICKY FROM AROUND MIDNIGHT THROUGH THE OVERNIGHT HOURS
AS THE WAVE LIFTS NORTHEAST OF THE AREA WITH LOSS OF ICE IN CLOUD
AND SOME LINGERING LIFT THROUGH THIS CLOUD. IF THERE IS INDEED
TOTAL ICE LOSS...COULD BE A BOUT OF FREEZING DRIZZLE. THIS LOOKS
MOST LIKELY FOR AREAS ALONG AND WEST OF THE MISSISSIPPI RIVER.
OTHERWISE...COULD SEE UP TO AN INCH OF SNOWFALL OVERNIGHT. WILL
ALSO SEE SOME FOG MAINLY ALONG/SOUTH OF I-90 WITH
WARMING/INCREASING MOISTURE THROUGH TONIGHT. THIS FOR THE MOST
PART LOOKS LIKE A SUB-HEADLINE EVENT...BUT WILL KEEP A CLOSE EYE
ON THE WEATHER AS IT EVOLVES.
FOR THURSDAY...MODELS SHOW MID-LEVEL RIDGING BUILDING BEHIND THE
DEPARTING WAVE THURSDAY MORNING...BUT WILL HAVE PLENTY OF LINGERING
MOISTURE/STRATUS FOR SOME PATCHY DRIZZLE AS WEAK LIFT CONTINUES
THROUGH THE SUPER-COOLED/ICE-LESS CLOUD LAYER. COULD SEE SOME PATCHY
FREEZING DRIZZLE AS WELL FOR AREAS THAT REMAIN BELOW 32 IN THE
MORNING. HOWEVER...ROADS SHOULD BE TREATED ENOUGH FOR MINIMAL TRAVEL
IMPACT. MOISTURE/PRECIPITATION CHANCES RAMP UP IN THE AFTERNOON
AHEAD OF A STRONGER WAVE MOVING OUT OF THE SOUTHERN PLAINS. WITH
HIGH TEMPERATURES PUSHING WELL INTO THE 30S...LOOKS LIKE A RAIN/SNOW
MIX SETTING UP. AS SUCH...NOT EXPECTING ANY APPRECIABLE SNOW
ACCUMULATIONS...PERHAPS A DUSTING/TENTH OF AN INCH IN SOME HIGHER
TERRAIN AREAS. IN ADDITION...LOOKS LIKE FOG WILL BE INCREASING AS
WELL AS THIS WARMING/MOIST AIR RIDES OVER THE EXISTING COLD SNOW
PACK. WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR DENSE FOG.
FOR THURSDAY NIGHT...MOISTURE WILL CONTINUE TO SPILL INTO THE AREA
AHEAD OF LOW PRESSURE MOVING INTO NORTHERN MO BY EARLY FRIDAY
MORNING. MODEL SOUNDING TEMPERATURE PROFILES SUPPORT A RAIN/SNOW MIX
ACROSS THE AREA WITH HIGHER TERRAIN FAVORING MORE SNOW THAN RAIN.
COULD SEE 1-2 INCHES ACROSS HIGHER TERRAIN AREAS MAINLY FROM
SOUTHEAST MN INTO NORTH CENTRAL WI.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 301 PM CST WED JAN 6 2016
FRIDAY WILL SEE THE LOW MOVE THROUGH EASTERN WI. LATEST
MODELS/THINKING IS THAT MAINLY RAIN WILL BE SEEN ACROSS MOST OF THE
AREA THROUGH THE DAY WITH RAIN/SNOW MIX FROM NORTHEAST IA/SOUTHEAST
MN INTO NORTH CENTRAL WI AS COLDER AIR FILTERS IN ON THE BACKSIDE OF
THE LOW. COULD SEE UP TO AN INCH OF ADDITIONAL SNOWFALL ACROSS THAT
AREA. OTHERWISE...LOOK FOR HIGH TEMPERATURES ACROSS THE AREA IN THE
MID TO UPPER 30S.
COLDER AIR FILTERS INTO THE AREA FRIDAY NIGHT INTO SATURDAY ALONG
WITH A CHANCE FOR LIGHT SNOW. LOOK FOR LOWS FRIDAY NIGHT MAINLY IN
THE 20S WITH HIGHS ON SATURDAY NOT BUDGING MUCH FROM THE OVERNIGHT
LOWS.
SMALL CHANCE OF SNOW LINGERS INTO SATURDAY NIGHT AS COLDER ARCTIC
AIR SPILLS INTO THE REGION. BY EARLY SUNDAY MORNING...WE WILL BE
LOOKING AT TEMPERATURE ONLY IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO ALONG WITH A FAIRLY STILL WIND IN THE 10 TO 20 MPH RANGE WITH A
FEW GUSTS AROU7ND 25 MPH. THIS WILL PRODUCE WIND CHILLS SUNDAY
MORNING IN THE MINUS 15 TO MINUS 25 DEGREE RANGE ACROSS SOUTHEAST
MN/NORTHEAST IA. WILL HAVE TO KEEP AN EYE ON THIS FOR POTENTIAL
WINDCHILL HEADLINES ACROSS THAT AREA.
MAIN STORY FOR SUNDAY THROUGH WEDNESDAY WILL BE ARCTIC AIRMASS
PAYING US A VISIT. HIGHS START OFF IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO SUNDAY...MODERATING SOME INTO THE SINGLE DIGITS/TEENS
ABOVE ZERO MONDAY THROUGH WEDNESDAY. OVERNIGHT LOWS LOOK TO BE IN
THE SINGLE DIGITS ABOVE/BELOW ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CST WED JAN 6 2016
LIGHT SNOW WILL SWITCH OVER TO LIGHT FREEZING DRIZZLE OVERNIGHT
INTO EARLY THURSDAY MORNING. IFR TO LIFR CONDITIONS ARE EXPECTED.
THE FREEZING DRIZZLE LOOKS TO SWITCH OVER TO LIQUID DRIZZLE
THURSDAY MORNING AS TEMPERATURES WARM ABOVE FREEZING. KRST COULD
DROP TO VLIFR AT TIMES THURSDAY MORNING IN FOG. ANOTHER STORM
SYSTEM THEN MOVES IN THURSDAY AFTERNOON INTO THURSDAY EVENING WITH
A RAIN SNOW MIX EXPECTED...SWITCHING OVER TO MAINLY SNOW LATE
THURSDAY NIGHT. IFR TO LIFR CONDITIONS ARE EXPECTED IN THE SNOW
THURSDAY NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
740 AM MST THU JAN 7 2016
.UPDATE...
ISSUED AT 739 AM MST THU JAN 7 2016
CURRENT RADAR IMAGERY SHOWS LIGHT SNOW IS TRYING TO FILL IN ALONG
THE FRONT RANGE. IN FACT...SOME LIGHT SNOW HAS ALREADY DEVELOPED
IN PORTIONS OF THE METRO AREA PER LATEST OBSERVATIONS FROM
CENTENNIAL AIRPORT. HRRR SEEMS TO HAVE BEST HANDLE ON THIS FOR
NOW...WEAKENING IT DURING THE DIURNAL MINIMA LATER THIS MORNING
INTO EARLY AFTERNOON...AND THEN INCREASING AGAIN THIS EVENING.
CURRENT FORECAST LOOKS ON TRACK...ONLY MINOR POP CHANGES THIS
MORNING TO REFINE AREAS OF LIGHT SNOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM MST THU JAN 7 2016
RADAR AND WEB CAMERAS INDICATE WIDESPREAD LIGHT SNOW HAS MOVED
OVER WESTERN AND CENTRAL COLORADO. LOOKING AT WATER VAPOR
SATELLITE IMAGERY...IT APPEARS DIFFLUENT FLOW ALOFT IS HELPING TO
PRODUCE THIS SNOW. EXPECT THE SNOW TO SLOWLY SHIFT EAST OVER THE
FRONT RANGE MOUNTAINS THIS MORNING. STILL UNCERTAIN IF SNOW WILL
MAKE ONTO THE URBAN CORRIDOR TODAY. IF IT DOES MAKE IT...SNOWFALL
WILL BE LIGHT AND THE SNOW WILL LIKELY MELT ON THE ROADWAYS DUE TO
TEMPERATURES NEAR THE FREEZING POINT. LOWERED POPS FOR TODAY
ACROSS THE DENVER AREA AND EASTERN PLAIN WHERE SNOW LOOKS LESS
CERTAIN. THE BEST CHANCE FOR SNOW LOOKS TO BE LATE THIS AFTERNOON
WITH THE NEXT WAVE MOVING INTO THE DESERT SOUTHWEST. THIS MAY BE
IN TIME FOR THE EVENING COMMUTE.
BETTER CHANCE FOR SNOW WILL BE TONIGHT WHEN THE SECOND WAVE
CURRENTLY MOVING ONTO THE SOUTHERN CALIFORNIA COAST MOVES OVER THE
FOUR CORNERS. THE ECMWF AND GEM CONTINUE TO LEAD THE WAY AND SHOW
AROUND A QUARTER INCH TO A THIRD INCH OF QPF FOR TONIGHT. THE 00Z
GFS IS STARTING TO CATCH UP TO THEM. EVEN THOUGH CONFIDENCE IS HIGH
THAT WE SEE SNOW...CONFIDENCE IN SNOWFALL AMOUNTS REMAINS LOW. A
SURFACE HIGH BUILDING OVER THE NORTHERN ROCKIES AND A SURFACE LOW
OVER NORTHEAST NEW MEXICO/NORTHWEST TEXAS WILL HELP PRODUCE UPSLOPE
FLOW LATE TONIGHT AND INTO FRIDAY. AIRMASS WILL BE MOIST TONIGHT
AND LAPSE RATES WILL BE 6 TO 8 C/KM. SO ANY LIFT WILL LIKELY
PRODUCE LIGHT SNOW.
WILL ISSUE AN ADVISORY FOR THE MOUNTAINS...FOOTHILLS AND DENVER AREA.
EXPECT 5-10 INCHES FOR THE MOUNTAINS WITH 4-8 SOUTHERN FOOTHILLS AND
3-7 FOR THE NORTHERN FOOTHILLS AND DENVER METRO AREA. MAIN IMPACT
FROM THIS SYSTEM WILL BE SNOWPACKED AND ICY ROADS TONIGHT AND FRIDAY
MORNING EVEN IF SNOWFALL AMOUNTS FALL SHORT OF ADVISORY CRITERIA.
SNOW IS EXPECTED TO BEGIN LATE THIS AFTERNOON OR EARLY EVENING AND
MAY CATCH THE EVENING COMMUTE. THE FRIDAY MORNING COMMUTE WILL
LIKELY BE SLOW AND SLIPPERY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 344 AM MST THU JAN 7 2016
THE FORECAST CONUNDRUM OF THE PAST COUPLE OF DAYS HAS IMPROVED SOME
THIS SHIFT WITH BETTER CONTINUITY IN THE 00Z AND 06Z MODEL RUNS.
MODELS HAVE CONVERGED UPON THE UPPER LEVEL CLOSED LOW OVER THE 4-
CORNERS THURSDAY EVENING TRACKING EAST-SOUTHEASTWARD ACRS NRN NEW
MEXICO DURING THE DAY FRIDAY. THERE`S ALSO BETTER AGREEMENT AS TO
WHEN A RATHER STG COLD FRONT WILL DROP SOUTH INTO NERN COLORADO AND
ARRIVE IN THE DENVER METRO AREA. THE LEADING EDGE OF THIS COLDER
AIRMASS APPEARS TO REACH THE DENVER AREA LATE THURSDAY NIGHT...BUT
THE MAIN PUSH OF COLD AIR ARRIVES WITH SFC-600 MB NELY WINDS OF 10-
20KTS DURING THE 12Z-18Z TIME INTERVAL ON FRIDAY AS THE UPPER LOW
PASSES TO OUR SOUTH. THIS IS ALSO THE PERIOD OF GREATEST QG ASCENT
OVER THE AREA...THOUGH NOTHING EXTRAORDINARY BY ANY MEANS. FORCING
ALOFT COMBINED WITH WEAK LEE SLOPE OROGRAPHICS/UPSLOPE FLOW AND A
MOIST LAPSE RATE TO AROUND 600 MBS SHOULD BE SUFFICIENT TO GENERATE
ANOTHER 1.5-4 INCHES OF SNOW ACROSS SRN PORTIONS OF THE I-25 URBAN
CORRIDOR INCLUDING THE DENVER METRO AREA AND ADJACENT FOOTHILLS...
WITH LESSER AMOUNTS IN AREAS TO THE NORTH AND EAST. RIDGE TOPS AND
EAST SLOPES IN MTN ZONES 33-34 COULD ALSO PICK UP ANOTHER 2-5 INCHES
DURING THE DAY FRIDAY. THE WINTER WEATHER ADVISORY FOR SNOW IS
SET TO EXPIRE AT 21Z/FRIDAY.
AFTER 21Z/FRIDAY...MODELS SHOW THE NELY UPSLOPE FLOW ON THE
PLAINS WEAKENING WITH THE CORE OF COLDEST AIR AND MAX SFC PRESSURE
PASSING TO OUR SOUTHEAST. DEPTH OF THE MOISTURE EAST OF THE FRONT
RANGE ALSO GRADUALLY LOWERS AS DRIER AIR BEGINS TO ENTRAIN
DOWNWARD FROM MID-LEVELS IN NWLY FLOW. AS A RESULT SHOULD SEE A
STEADY DECLINE IN SNOWFALL INITIALLY ALONG THE FRONT RANGE AND
EVENTUALLY OUT ACROSS THE PLAINS BY AROUND MIDNIGHT. IF IT WERE
NOT FOR THE LINGERING CLOUD COVER OVERNIGHT TEMPERATURES WOULD
CERTAINTY PLUNGE BELOW ZERO IN MANY AREAS WITH THE FRESH SNOW
COVER AND LIGHT WINDS. HIGH TEMPERATURES ON FRIDAY AT LEAST 10
DEG F LOWER THAN THOSE TODAY DUE TO HEAVY CLOUD COVER...SNOWFALL
AND ONGOING COLD AIR ADVECTION.
LOOKING AHEAD TO THE WEEKEND...TEMPERATURES WILL STRUGGLE TO WARM
WITH LINGERING CLOUD COVER AND WEAK COLD AIR ADVECTION WITH
NORTHWEST FLOW SFC AND ALOFT. A WEAK WEATHER DISTURBANCE/SHORTWAVE
TROUGH MOVING ALONG MODERATE NWLY FLOW ALOFT IS FORECAST BY A
MAJORITY OF THE MODELS TO CLIP NERN COLORADO DURING THE SATURDAY
AFTERNOON/EVENING TIME FRAME. COULD SEE AN UPTICK IN HIGH COUNTRY
SNOWFALL WITH ITS PASSAGE AS WELL AS A SLIGHT CHANCE OF LIGHT SNOW
ON THE PLAINS...MAINLY ACROSS THE NORTHEAST CORNER OF THE CWA.
ADDITIONAL SNOW AMOUNTS GENERALLY LESS THAN 2 INCHES FOR THE HIGH
COUNTRY AND PRETTY MUCH NOTHING ON THE PLAINS. TEMPERATURE GUIDANCE
NOW IN BETTER AGREEMENT WITH HIGHS IN THE 20S ON THE PLAINS BOTH
DAYS AND TEENS/LOW 20S IN THE MTNS/HIGH VALLEYS. HIGH MTN VALLEY
LOWS WILL TURN QUITE COLD AGAIN BUT NO WHERE AS BITTER COLD AS THEY
WERE SEVERAL DAYS AGO.
NEXT WEEK LOOKS DRY AND WARMER WITH A HIGH RIDGE BUILDING IN FROM
THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 739 AM MST THU JAN 7 2016
AREAS OF LIGHT SNOW DEVELOPING ALONG THE FRONT RANGE THIS MORNING.
THIS IS A FEW HOURS AHEAD OF TIME AND ONLY ADVERTISED BY
MESOSCALE MODELS OF YESTERDAY. NOW...SEEMS HRRR CATCHING BACK ON.
MOST OF THIS SNOW SHOULD REMAIN LIGHT WITH POTENTIAL FOR MINOR
SNOW ACCUMULATIONS LESS THAN 1 INCH...AND SOME MELTING EXPECTED ON
PAVED SURFACES. BAND OF LIGHT SNOW IS IN THE KAPA TO KDEN
CORRIDOR...BUT MAY SHIFT TO KBJC AND KFNL BEFORE A GRADUAL
WEAKENING EXPECTED TOWARD 18Z- 20Z.
OTHERWISE...A SERIES OF PACIFIC SYSTEMS WILL BRING MOISTURE TO
THE AREA. CLOUDS WILL LOWER THROUGH THE DAY WITH ILS LANDINGS.
CEILINGS ARE EXPECTED TO FALL BELOW 3000 FEET WITH AREAS OF LIGHT
SNOW THIS MORNING...AND THEN BECOME MORE PERSISTENT AFTER 21Z THIS
AFTERNOON. WIDESPREAD SNOW IS EXPECTED AFTER 00Z WITH VISIBILITY
RANGING FROM 1 TO 3 MILES. CEILINGS WILL BE 500 TO 2000 FEET.
WINDS WILL BE LIGHT AND TURN NORTHEAST AROUND 06Z. TOTAL SNOWFALL
AT KDEN THROUGH 18Z FRIDAY IS EXPECTED TO BE 3 TO 5 INCHES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 2 PM MST
FRIDAY FOR COZ035-036-039>041.
WINTER WEATHER ADVISORY UNTIL 2 PM MST FRIDAY FOR COZ033-034.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...MEIER
LONG TERM...BAKER
AVIATION...BARJENBRUCH/MEIER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1000 AM CST THU JAN 7 2016
.UPDATE...LATEST SATELLITE IMAGERY AND UPPER AIR ANALYSIS SHOWED A
LOW TO MID LEVEL CLOSED LOW OVER THE TEXAS PANHANDLE WITH AN
ASSOCIATED SHORT WAVE EXTENDING SOUTHEAST THROUGH THE ARKLATEX
REGION. THERE WAS SOME UPPER DIVERGENCE FROM THE WEST WITH SOME LOW
LEVEL SOUTHERLY FLOW. THERE WAS WEAK MOISTURE TRANSPORT AS AREA
RADARS WERE PICKING UP SOME LIGHT SHOWERS AROUND THE MS RIVER AREA.
JAN 12Z SNDING SHOWED A LAYER OF DRY AIR ABOUT 4KFT THICK WHICH WAS
MAKING THE PRECIP A LITTLE TOUGHER TO MAKE IT TO THE SFC...WHICH HAS
RESULTED IN VERY LIGHT RAINFALL. AREA SNDGS WERE SHOWING PWATS UNDER
0.50 INCH. LATEST CONVECTIVE ALLOWING GUIDANCE SHOWED THAT THE
PRECIP WILL BREAK UP AS IT MOVES EAST OF INTERSTATE 55 FOR THIS
AFTERNOON AND DECREASE IN COVERAGE AS IT MOVES FARTHER AWAY FROM
UPPER SHORTWAVE ENERGY SUPPORT. 12Z NAM AND HRRR SHOWS SOME ELEVATED
INSTABILITY FOR SOME ISOLATED THUNDER POTENTIAL FOR LATE THIS
MORNING INTO THIS AFTERNOON. SO WITH THIS IN MIND HAVE LOWERED TODAY
AND TONIGHT POPS TO THE CHANCE CATEGORY WITH ISOLATED THUNDER. AS
FAR AS TEMPS ARE CONCERN WILL HOLD ON TO CURRENT HIGHS IN THE MIDDLE
50S NORTH TO THE LOWER 60S SOUTHWEST./17/
&&
.AVIATION...LIGHT RAIN WITHOUT MUCH VSBY RESTRICTION WILL PUSH
THROUGH THE AREA TODAY. AS THE RAIN MOVES EAST OF THE AREA LATER
TODAY AND TONIGHT...IFR CIGS ARE EXPECTED TO PUSH INTO THE AREA.
THERE IS THE POSSIBILITY OF LIFR CIGS AND VSBY LATE TONIGHT INTO
FRIDAY MORNING. WILL BE EVALUATING THAT POTENTIAL FOR THE 18Z
TAF ISSUANCE. /SW/
&&
./PREVIOUS DISCUSSION...405 AM CST THU JAN 7 2016
.SHORT TERM...TODAY THROUGH FRIDAY...SHOWERS AND ISOLATED
THUNDERSTORMS ARE MOVING ACROSS LOUISIANA THIS MORNING ASSOCIATED
WITH A SHORT WAVE IN EAST TEXAS. THESE SHOWERS WILL CONTINUE TO MOVE
INTO OUR WESTERN PARISHES BY 10-12Z AND MOVE ACROSS OUR AREA THROUGH
THE AFTERNOON HOURS. MODELS SUGGEST ENOUGH INSTABILITY FOR AT LEAST
ISOLATED THUNDERSTORM ACTIVITY ACROSS THE AREA LATER THIS MORNING
AND AFTERNOON. IT CONTINUES TO LOOK LIKE RAINFALL AMOUNTS WILL
GENERALLY BE ON THE LIGHT SIDE...BUT SOME AREAS COULD RECEIVE
ANYWHERE FROM AROUND A QUARTER TO A HALF INCH. LIGHT RAINSHOWERS
WILL CONTINUE TO BE POSSIBLE INTO THE EVENING HOURS IN THE EAST
BEFORE ENDING OVERNIGHT AS MUCH DRIER AIR BUILDS IN.
PWATS WILL GENERALLY REMAIN BELOW A HALF AN INCH ON FRIDAY AND WITH
WITH STRONG SOUTHERLY FLOW...TEMPERATURES WILL CLIMB INTO THE UPPER
60S TO AROUND 70 FOR MUCH OF THE AREA./15/
.LONG TERM...FRIDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK...THE
SOUTHERN BRANCH OF THE JET STREAM LOOKS TO REMAIN ACTIVE AND
SUPPRESSED INCREASINGLY TO THE SOUTH OVER THE LONG TERM PERIOD.
TEMPERATURES SHOULD TREND BELOW NORMAL.
THE FIRST DISTURBANCE IN THE LONG TERM PERIOD (WHICH WE HAVE BEEN
WATCHING FOR A WHILE) IS NOW PLOWING TOWARD THE FOUR CORNERS REGION
AFTER BRINGING CALIFORNIA ANOTHER HEAVY DOSE OF PRECIPITATION.
MODELS CONTINUE TO SPEED UP WITH THE FAST PROGRESSION OF THIS SYSTEM
TOWARDS THE LOWER MS VALLEY...AND IT NOW LOOKS LIKE MOST OF THE
AREA`S PCPN WITH THIS SYSTEM MAY FALL BETWEEN MIDNIGHT FRIDAY NIGHT
AND 10 AM SATURDAY MORNING. THE UPPER AIR DISTURBANCE IS VERY POTENT
AND DEEP AND IT SHOULD ALSO GENERATE A SURFACE LOW WHICH TRACKS
QUICKLY BY THE NORTHWEST CORNER OF THE REGION DURING THIS TIME.
DESPITE THIS SOMEWHAT WORRISOME-SOUNDING COMBO...AND THE FACT THAT
LAPSE RATES ALOFT WILL BE STEEP...NO HAZARDOUS WEATHER IS EXPECTED
AT THIS TIME. THE REASONING FOR THE LATTER IS PRIMARILY DUE TO
LIMITED MOISTURE GETTING INCORPORATED INTO THIS SYSTEM IN OUR
REGION (MAINLY BECAUSE IT IS COMING SO QUICKLY ON THE HEELS OF
TODAY`S INCLEMENT WEATHER). STILL...WE COULD DEFINITELY EXPERIENCE A
FEW STORMS EMBEDDED IN THE SHOWERS LATE FRIDAY NIGHT THROUGH MIDDAY
SATURDAY...AND IT IS NOT INCONCEIVABLE THAT A FEW STORMS COULD
PRODUCE SOME SMALL HAIL OWING TO VERY COLD TEMPERATURES ALOFT. A
PLEASANT BY-PRODUCT OF THE FORWARD ADJUSTMENT OF THE SCHEDULE
OF SATURDAY`S RAIN IS THAT SOME AREAS (PARTICULARLY OVER NE LA
AND SOUTHERN MS) COULD EXPERIENCE A FEW HOURS OF SUN IN THE
AFTERNOON WITH TEMPS NOT TOO SHABBY.
BUT BY SATURDAY NIGHT THE EXPECTED COLD FRONT STILL LOOKS TO COME IN
FROM THE NORTHWEST AND PASS THROUGH ALL THE REGION BY SUNDAY
MORNING. TEMPERATURES WILL FALL OFF PRETTY QUICKLY IN THE WAKE OF
THE BOUNDARY WITH GUSTY NORTHWEST WINDS TO INCREASE THE WIND CHILL.
FORTUNATELY...AT LEAST SCATTERED SUNSHINE IN THE AFTERNOON SHOULD
HELP WARM TEMPS SOLIDLY ABOVE THE 40 DEGREE MARK EVERYWHERE EXCEPT
ALONG AND NORTH OF THE HIGHWAY 82 CORRIDOR.
SUNDAY NIGHT INTO TUESDAY WILL FEATURE SEASONABLY CHILLY TEMPS AND
MOSTLY CLEAR TO PARTLY CLOUDY SKIES UNDER THE INFLUENCE OF SURFACE
HIGH PRESSURE. EXPECT THE ENTIRE REGION TO GET BELOW OR VERY NEAR
FREEZING SUNDAY AND MONDAY NIGHTS.
A REINFORCING COLD FRONT LOOKS TO SLIDE ACROSS THE REGION SOMETIME
LATE TUESDAY OR TUESDAY NIGHT AND SHOULD BE DRY...WITH THE BULK OF
THE FRIGID AIR REMAINING TO OUR NORTH. DESPITE THE LATTER FACT THE
PASSAGE OF THIS FRONT WILL WORK TO PROLONG OUR SEASONABLY CHILLY
TEMPS WELL INTO NEXT WEEK. THE PASSAGE OF A GULF LOW TO OUR SOUTH
STILL LOOKS POSSIBLE BETWEEN LATE WEDNESDAY AND NEXT THURSDAY WHICH
COULD BRING ANOTHER SHOT OF PCPN TO AT LEAST SOUTHERN ZONES. AT THIS
POINT THE POTENTIAL FOR ANY WINTRY WEATHER WITH THIS POSSIBLE SYSTEM
IS NOT LOOKING VERY HIGH...BUT IT IS OF COURSE SOMETHING WE WILL BE
KEEPING OUR EYE ON. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 57 45 70 52 / 37 26 9 61
MERIDIAN 56 43 67 50 / 42 40 9 55
VICKSBURG 58 46 71 53 / 51 20 12 67
HATTIESBURG 59 45 72 53 / 41 25 7 67
NATCHEZ 60 50 70 53 / 59 16 12 69
GREENVILLE 53 47 66 51 / 37 27 11 66
GREENWOOD 55 47 67 51 / 37 39 11 63
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
17/SW/15/BB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
525 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 525 AM CST THU JAN 7 2016
DENSE FOG HAD BECOME A BIT MORE WIDESPREAD THE PAST FEW HOURS...SO
DECIDED TO ISSUE A DENSE FOG ADVISORY UNTIL 9 AM CST FOR A LARGE
PART OF THE FORECAST AREA. NO OTHER CHANGES TO PREVIOUS FORECAST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
THE MAIN FORECAST ISSUES REVOLVE AROUND PCPN TYPE AND PCPN AMOUNTS...
INCLUDING SOME LIGHT SNOW ACCUMULATIONS.
UPPER AIR CHARTS FROM 00Z SHOWED THE FOLLOWING MAIN FEATURES. AT
300 MB...STRONGEST WINDS (UP TO ABOUT 130 KNOTS) WERE MOVING
EASTWARD FROM THE PACIFIC ACROSS NORTHERN MEXICO. A BLOCKING
RIDGE AT 500 MB WAS CENTERED ALONG THE BORDER OF THE YUKON AND
NORTHWEST TERRITORIES...WHILE A TROUGH STRETCHED FROM THE GULF OF
ALASKA DOWN TO OFF THE CALIFORNIA COAST. AT 700 MB...THERE WAS A
LACK OF A BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS. THE COLDEST
AIR AT THIS LEVEL WAS ALONG THE WEST COAST. THERE WAS MORE OF A
THERMAL CONTRAST NOTED AT 850 MB ACROSS THE NORTHERN AND CENTRAL
PLAINS...WITH -8 C AT KBIS...RANGING TO +2C AT KTOP. THE KOAX
SOUNDING SHOWED ABOUT 0.51 INCHES OF PW...AND IT WAS NEARLY
SATURATED UP TO 6000 FEET AGL. SFC ANALYSIS EARLY THIS MORNING
SHOWED LOW PRESSURE CENTERS OVER COLORADO AND EASTERN SOUTH
DAKOTA. SOUTHEAST SURFACE WINDS WERE IN PLACE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH TEMPERATURES IN THE LOWER AND
MID 30S.
A SHORTWAVE HAD MOVED ACROSS THE CENTRAL PLAINS YESTERDAY...AND WAS
MOVING TOWARD THE WESTERN GREAT LAKES REGION. THE NEXT SHORTWAVE OF
CONCERN WAS DEPICTED FAIRLY WELL WITH A COMBINATION OF RECENT WATER
VAPOR SATELLITE IMAGERY AND RUC MODEL INITIALIZATIONS...NEAR THE
BORDER OF NEW MEXICO...TEXAS AND OKLAHOMA. THAT FEATURE SHOULD MOVE
TOWARD CENTRAL KANSAS BY LATE AFTERNOON AND HELP BRING INCREASING
MOISTURE (DEEPER) AND LIFT TO THE LOCAL AREA. AREAS OF DRIZZLE...
FOG AND LIGHT RAIN SHOULD PERSIST THIS MORNING...WITH LIGHT RAIN
BECOMING MORE WIDESPREAD IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
THIS AFTERNOON. THERE WILL BE A CHANCE OF A MIX OF SNOW...SLEET
AND RAIN IN MUCH OF NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
THE SHORTWAVE TROUGH THAT IS EXPECTED TO BE OVER KANSAS BY LATE
AFTERNOON WILL TRACK NORTHEAST INTO SOUTHERN IOWA FRIDAY AND WEAKEN.
THEN A MORE COMPLEX LIFT PATTERN WILL OCCUR AS ANOTHER DISTURBANCE
LIFTS EAST/NORTHEAST ACROSS KANSAS FRIDAY NIGHT INTO SATURDAY
MORNING AND A COLD TROUGH STARTS DIGGING INTO THE NORTHERN PLAINS.
MIXED PCPN SHOULD CHANGE TO MOSTLY SNOW IN NORTHEAST NEBRASKA AS
WINDS SHIFT TO THE NORTH TONIGHT AND A FEW INCHES OF SNOW MAY
ACCUMULATE. COLDER AIR WILL SPREAD OVER THE REST OF THE AREA FOR
LATE TONIGHT AND THROUGH FRIDAY...WHICH WILL CHANGE THE PCPN TO
MAINLY SNOW FROM NORTHWEST TO SOUTHEAST BY FRIDAY NIGHT. THE SNOW
SHOULD END SATURDAY...AS COLD HIGH PRESSURE STARTS TO BUILD INTO
THE AREA. BY 00Z SUNDAY...HIGH PRESSURE WITH A CENTER OF ABOUT
1031 MB SHOULD BE OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
COLD AIR SHOULD DOMINATE THE FIRST PART OF THIS PERIOD...AS A COLD
NORTH/NORTHWEST FLOW ALOFT BRINGS CANADIAN AIR DOWN INTO OUR AREA.
TEMPERATURES ARE EXPECTED TO MODERATE A BIT BY WEDNESDAY AND
THURSDAY...AS THE FLOW TURNS MORE TOWARD THE WEST. AT THIS TIME...
NO SIGNIFICANT PCPN IS EXPECTED. LIGHT SNOW IS POSSIBLE MONDAY
OVER THE DAKOTAS AND MINNESOTA. AT THIS TIME...EXPECT THAT TO STAY
TO THE NORTH OF OUR AREA.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 512 AM CST THU JAN 7 2016
LIFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD. VISIBILITIES
RANGING FROM 1/4 TO 1/2 MILE AT KOFK AND KLNK...AND 1/2 TO 1 AT
KOMA. SHOULD SEE RAIN DEVELOP AT KLNK/KOMA BY 19Z AND CONTINUE...
POSSIBLY BECOMING A WINTRY MIX BY 08/08Z. SNOW DEVELOPS AT KOFK
BY 22Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NEZ011-012-
016>018-030>033-042>045-050>053-065>068-078-088>090.
IA...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ069-079-
090.
&&
$$
UPDATE...MILLER
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
515 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
THE MAIN FORECAST ISSUES REVOLVE AROUND PCPN TYPE AND PCPN AMOUNTS...
INCLUDING SOME LIGHT SNOW ACCUMULATIONS.
UPPER AIR CHARTS FROM 00Z SHOWED THE FOLLOWING MAIN FEATURES. AT
300 MB...STRONGEST WINDS (UP TO ABOUT 130 KNOTS) WERE MOVING
EASTWARD FROM THE PACIFIC ACROSS NORTHERN MEXICO. A BLOCKING
RIDGE AT 500 MB WAS CENTERED ALONG THE BORDER OF THE YUKON AND
NORTHWEST TERRITORIES...WHILE A TROUGH STRETCHED FROM THE GULF OF
ALASKA DOWN TO OFF THE CALIFORNIA COAST. AT 700 MB...THERE WAS A
LACK OF A BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS. THE COLDEST
AIR AT THIS LEVEL WAS ALONG THE WEST COAST. THERE WAS MORE OF A
THERMAL CONTRAST NOTED AT 850 MB ACROSS THE NORTHERN AND CENTRAL
PLAINS...WITH -8 C AT KBIS...RANGING TO +2C AT KTOP. THE KOAX
SOUNDING SHOWED ABOUT 0.51 INCHES OF PW...AND IT WAS NEARLY
SATURATED UP TO 6000 FEET AGL. SFC ANALYSIS EARLY THIS MORNING
SHOWED LOW PRESSURE CENTERS OVER COLORADO AND EASTERN SOUTH
DAKOTA. SOUTHEAST SURFACE WINDS WERE IN PLACE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH TEMPERATURES IN THE LOWER AND
MID 30S.
A SHORTWAVE HAD MOVED ACROSS THE CENTRAL PLAINS YESTERDAY...AND WAS
MOVING TOWARD THE WESTERN GREAT LAKES REGION. THE NEXT SHORTWAVE OF
CONCERN WAS DEPICTED FAIRLY WELL WITH A COMBINATION OF RECENT WATER
VAPOR SATELLITE IMAGERY AND RUC MODEL INITIALIZATIONS...NEAR THE
BORDER OF NEW MEXICO...TEXAS AND OKLAHOMA. THAT FEATURE SHOULD MOVE
TOWARD CENTRAL KANSAS BY LATE AFTERNOON AND HELP BRING INCREASING
MOISTURE (DEEPER) AND LIFT TO THE LOCAL AREA. AREAS OF DRIZZLE...
FOG AND LIGHT RAIN SHOULD PERSIST THIS MORNING...WITH LIGHT RAIN
BECOMING MORE WIDESPREAD IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
THIS AFTERNOON. THERE WILL BE A CHANCE OF A MIX OF SNOW...SLEET
AND RAIN IN MUCH OF NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
THE SHORTWAVE TROUGH THAT IS EXPECTED TO BE OVER KANSAS BY LATE
AFTERNOON WILL TRACK NORTHEAST INTO SOUTHERN IOWA FRIDAY AND WEAKEN.
THEN A MORE COMPLEX LIFT PATTERN WILL OCCUR AS ANOTHER DISTURBANCE
LIFTS EAST/NORTHEAST ACROSS KANSAS FRIDAY NIGHT INTO SATURDAY
MORNING AND A COLD TROUGH STARTS DIGGING INTO THE NORTHERN PLAINS.
MIXED PCPN SHOULD CHANGE TO MOSTLY SNOW IN NORTHEAST NEBRASKA AS
WINDS SHIFT TO THE NORTH TONIGHT AND A FEW INCHES OF SNOW MAY
ACCUMULATE. COLDER AIR WILL SPREAD OVER THE REST OF THE AREA FOR
LATE TONIGHT AND THROUGH FRIDAY...WHICH WILL CHANGE THE PCPN TO
MAINLY SNOW FROM NORTHWEST TO SOUTHEAST BY FRIDAY NIGHT. THE SNOW
SHOULD END SATURDAY...AS COLD HIGH PRESSURE STARTS TO BUILD INTO
THE AREA. BY 00Z SUNDAY...HIGH PRESSURE WITH A CENTER OF ABOUT
1031 MB SHOULD BE OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
COLD AIR SHOULD DOMINATE THE FIRST PART OF THIS PERIOD...AS A COLD
NORTH/NORTHWEST FLOW ALOFT BRINGS CANADIAN AIR DOWN INTO OUR AREA.
TEMPERATURES ARE EXPECTED TO MODERATE A BIT BY WEDNESDAY AND
THURSDAY...AS THE FLOW TURNS MORE TOWARD THE WEST. AT THIS TIME...
NO SIGNIFICANT PCPN IS EXPECTED. LIGHT SNOW IS POSSIBLE MONDAY
OVER THE DAKOTAS AND MINNESOTA. AT THIS TIME...EXPECT THAT TO STAY
TO THE NORTH OF OUR AREA.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 512 AM CST THU JAN 7 2016
LIFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD. VISIBILITIES
RANGING FROM 1/4 TO 1/2 MILE AT KOFK AND KLNK...AND 1/2 TO 1 AT
KOMA. SHOULD SEE RAIN DEVELOP AT KLNK/KOMA BY 19Z AND CONTINUE...
POSSIBLY BECOMING A WINTRY MIX BY 08/08Z. SNOW DEVELOPS AT KOFK
BY 22Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
645 AM EST THU JAN 07 2016
.SYNOPSIS...HIGH PRESSURE WILL CONTINUE TO EXTEND INTO THE AREA FROM
THE MID-ATLANTIC STATES THROUGH THE END OF THE WEEK. MEANWHILE...A
WEAKENING LOW PRESSURE SYSTEM WILL IMPACT THE AREA FRIDAY...FOLLOWED
BY A STRONGER SYSTEM AND UNSETTLED WEATHER ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM THURSDAY..
HIGH PRESSURE...MAINTAINED BY SHORTWAVE RIDGING ALOFT...CONTINUES TO
EXTEND FROM THE MID-ATLANTIC STATES THROUGH THE NC PIEDMONT...WITH A
FAIRLY PRONOUNCED INVERTED TROUGH OFFSHORE. ALOFT...THE FLOW IS
GENERALLY WEAK SOUTHWESTERLY WITH DISTURBANCES OFF THE GA/FL COAST
AND OVER THE SOUTHERN PLAINS. A SHALLOW LAYER OF MOISTURE IN
SOUTHEASTERLY FLOW ATOP THE SURFACE RIDGE HAS LED TO WIDESPREAD
STRATUS AND A SMALL AREA OF RECENTLY EXPANDING DRIZZLE JUST EAST OF
THE TRIANGLE AREA...WHICH ITSELF APPEARS TO BE FOCUSED WITHIN THE
REGION OF STRONGEST 925MB WARM ADVECTION. THE MOISTURE IS
SHALLOW...THOUGH SLIGHTLY DEEPER TOWARD THE COAST...AND LUCKILY
DEWPOINTS HAVE RECOVERED INTO THE 30S EVERYWHERE EXCEPT FOR THE FAR
WESTERN PIEDMONT. THIS POORLY RESOLVED AREA OF DRIZZLE SHOULD SHIFT
NORTH-NORTHWESTWARD THIS MORNING AND NOT CAUSE ANY PROBLEMS.
OTHERWISE TODAYS FORECAST CHALLENGE IS WHETHER OR NOT THE STRATUS
WILL PERSIST THROUGH THE DAY. THE 925NMB FLOW SHOULD BACK TO MORE
NORTHEASTERLY THIS MORNING IN RESPONSE TO THE AREA OF LOW PRESSURE
DEVELOPING WELL OFF THE SOUTHEAST COAST...AND THUS THE WARM
ADVECTION WILL DIMINISH. THE NAM AND GFS MAINTAIN THE STRATUS
THROUGH THIS AFTERNOON ON THE EAST WHERE THE MOISTURE IS ALREADY
DEEPER...WHILE BREAKING THE WESTERN PIEDMONT OUT. RAP RUNS HAVE
TENDED TO SCATTER OUT THE ENTIRE AREA. WILL TREND THE FORECAST
TOWARD A LITTLE LESS CLOUD COVER BY THIS AFTERNOON...ADMITTEDLY WITH
LOW CONFIDENCE. HIGHS MAY FEATURE A MORE EVEN DISTRIBUTION THAT
USUAL...WITH MID AND UPPER 40S FOR MOST AREAS. HOWEVER...IF CLOUDS
DO SCATTER THEN LOWER 50S ARE POSSIBLY FOR THE EASTERN HALF OF THE
AREA.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
AS OF 340 AM THURSDAY...
WHAT MOISTURE IS STILL AROUND THIS EVENING SHOULD LEAD TO
REDEVELOPING STRATUS BENEATH THE INVERSION ALOFT TONIGHT.
MEANWHILE... THE AFOREMENTIONED UPPER DISTURBANCE OVER THE SOUTHERN
PLAINS WILL LIFT TOWARD THE UPPER MIDWEST TONIGHT AND FRIDAY..WHILE
THE EASTERN EXTENT OF THE TROUGH AXIS AND DCVA LIFT ACROSS THE
SOUTHEAST US. THE LEFT EXIT REGION OF THE STJ WILL PROVIDE SOME
UPPER DIVERGENCE...BUT LOW-LEVEL FORCING IS LACKING WITH THE COASTAL
TROUGH STAYING PUT AND PRETTY WEAK LOW-LEVEL FLOW/ADVECTION. THE
TREND IN THE MODELS TOWARD A DRIER FORECAST HAS STABILIZED AND THE
NAM/GFS/ECMWF ALL INDICATED JUST SOME VERY LIGHT SHOWERS DURING THE
DAY ON FRIDAY. WILL MAINTAIN A SLIGHT CHANCE TO CHANCE POP AFTER
12Z FRIDAY AND NO POPS FRIDAY NIGHT AHEAD OF THE NEXT SYSTEM TO
IMPACT THE AREA ON SATURDAY.
LOWS TONIGHT WILL DEPEND HOW MUCH WE SCATTER OUT TODAY AND HOW
QUICKLY CLOUDS INCREASE OVERNIGHT AHEAD OF THE APPROACHING TROUGH.
GIVEN NO CHANGE IN THE AIR MASS AND POTENTIAL FOR OVERCAST
AGAIN...LOWS SHOULD BE SIMILAR TO THIS MORNING...34-42 NW TO SE.
HIGHS FRIDAY COULD BE LOWER WITH MORE PRECIP...BUT WILL STILL
FEATURE A CAD-LIKE RANGE GIVEN THE SURFACE HIGH AND DIABATIC EFFECTS
OF THE LOW CLOUDS...MID 40S NW TO MID 50S SOUTHEAST. AND FINALLY
FRIDAY NIGHT LOWS WILL BE A TAD MILDER IN THE 40-48 RANGE AS
DEWPOINTS CREEP UP INTO THE LOWER 40S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 400 AM THURSDAY...
FORECAST CONFIDENCE CONTINUES TO INCREASE WITH RESPECT TO THE NEXT
RELATIVELY SIGNIFICANT SYSTEM EXPECTED TO AFFECT CENTRAL NC WITH A
HIGH PROBABILITY OF RAIN...AND ASSOCIATED WEAK HYBRID COLD AIR
DAMMING...EARLY THIS WEEKEND. IN FACT...THE MODELS ARE IN GOOD
OVERALL AGREEMENT REGARDING THE SYNOPTIC PATTERN...ONE CHARACTERIZED
BY A PRIMARY SURFACE LOW TRACK INTO THE GREAT LAKES AND SECONDARY
DEVELOPMENT ALONG A RETREATING COASTAL FRONT FROM THE GULF COAST TO
THE MIDDLE ATLANTIC PIEDMONT SAT-SAT NIGHT. THE PASSAGE OF THE
SECONDARY/TRIPLE POINT LOW AND ASSOCIATED LOW LEVEL THETA-E
ADVECTION MAY ALSO SUPPORT A FEW ELEVATED STORMS DURING THE
AFTERNOON AND EVENING SAT. THE EARLIER INDICATED FASTER TREND WITH
THIS SYSTEM REMAINS...WITH MOST OR ALL OF THE SHOWERS EAST AND
NORTHEAST OF CENTRAL NC BY DAYBREAK SUNDAY.
OTHERWISE...THE PATTERN FOR EARLY TO MID NEXT WEEK APPEARS TO BE A
RELATIVELY COOL AND DRY ONE...AS A BROAD TROUGH BECOMES ESTABLISHED
ACROSS THE EASTERN TWO THIRDS OF THE COUNTRY. THE ONE EXCEPTION WILL
BE A BRIEF PERIOD OF LIFT AS A SHORTWAVE TROUGH AND ACCOMPANYING JET
STREAK IN NW FLOW ALOFT AMPLIFY ACROSS THE APPALACHIANS LATE TUE
NIGHT-EARLY WED...AT WHICH TIME A FEW FLURRIES OR SPRINKLES WOULD BE
POSSIBLE IN AN OTHERWISE DRY REGIME BETWEEN UPSLOPE APPALACHIAN
PRECIPITATION AND OFFSHORE LOW PRESSURE...THE LATTER OF WHICH WOULD
BE SUPPORTED ALOFT BY THE AFOREMENTIONED SHORTWAVE TROUGH IN NW FLOW
ALOFT...WHICH MAY GRAZE COASTAL AREAS OF THE NORTHERN MIDDLE
ATLANTIC STATES AND/OR NEW ENGLAND ON WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 645 AM THURSDAY...
SOUTHEASTERLY LOW LEVEL FLOW ABOVE THE HIGH PRESSURE AND NORTHEASTERLY
WINDS AT THE SURFACE CONTINUES TO SUPPORT LIFR TO MVFR CEILINGS AND
EVEN A LITTLE DRIZZLE AROUND KRDU AND TO THE EAST. THE MOIST LAYER
IS ONLY 1000 FT OR SO THICK BASED ON LAST EVENINGS RAOBS AND RECENT
PIREPS. THE LOW LEVEL FLOW IS FORECAST TO BACK AROUND TO
NORTHEASTERLY TODAY IN RESPONSE TO A SURFACE LOW OFF THE SOUTHEAST
COAST...WHICH SHOULD ALLOW SOME BREAKS IN THE STRATUS TO DEVELOP.
MODELS HAVE NOT BEEN IN GOOD AGREEMENT ON THE EXTENT OF THE BREAKS
AND WHEN VFR CONDITIONS COULD DEVELOP. GIVEN THE UNCERTAINTY...THE
CURRENT TAF WILL SHOW CONDITIONS IMPROVING TO MVFR BY EARLY
AFTERNOON...WITH IFR CONDITIONS REDEVELOPING OVERNIGHT.
OUTLOOK...A COUPLE OF LOW PRESSURE SYSTEMS WILL IMPACT THE REGION
THROUGH THE WEEKEND. DESPITE VERY LITTLE RAIN WILL THE FIRST
SYSTEM ON FRIDAY...MVFR/IFR CEILINGS ARE EXPECTED...CONTINUING
THROUGH SATURDAY AS A STRONGER SYSTEM BRING WIDESPREAD RAIN.
IMPROVING CONDITIONS ARE EXPECTED BY SUNDAY AND MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...22
SHORT TERM...22
LONG TERM...2
AVIATION...22
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
600 AM EST THU JAN 7 2016
.SYNOPSIS...
HIGH PRESSURE WILL PUSH DOWN THE COAST THROUGH FRIDAY WHILE A
COASTAL FRONT LINGERS OFFSHORE. A WEAK MID LEVEL IMPULSE WILL
BRING A CHANCE FOR SHOWERS ON FRIDAY. A WARM FRONT WILL LIFT
ACROSS THE AREA SATURDAY BRINGING GOOD CHANCES FOR RAIN INTO
SUNDAY ALONG WITH MUCH WARMER TEMPERATURES. MUCH COLDER
TEMPERATURES WILL FOLLOW A COLD FRONT EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM THURSDAY...WEAKENING HIGH PRESSURE WEDGE THE PRIMARY
FEATURE TODAY AND TONIGHT ACCOMPANIED BY MULTIPLE CLOUD LAYERING.
SOUTHERLY WINDS ABOVE 500 MB WILL DIRECT A COAT OF CIRRUS THROUGH
SC AND THE DEEPER INTERIOR OF SE NC...WITH A SMATTERING OF LOW
CLOUDS TRAPPED BENEATH A NOTABLE INVERSION TODAY. A TROUBLESOME
SKY FORECAST AS VARIABILITY IS EXPECTED NEAR THE COAST WITH MORE
STUBBORN COVERAGE LIKELY INLAND. THIS COMPLICATES MAXIMUM TEMPS
BUT MIDDLE 50S WELL INLAND TO NEAR 60 AT THE COAST ANTICIPATED.
STEERING FLOW WILL KEEP OCEAN SHOWERS MAINLY AT SEA AND THERE IS
LITTLE FORCING OVER LAND TO TRIGGER PCPN TODAY. AN EXCEPTIONALLY
DRY MID-LAYER WILL HOLD ITS GROUND TODAY. TONIGHT SHORT-WAVE
IMPULSING AND WEAK ISENTROPIC OMEGA FROM THE SW WILL ARRIVE IN THE
PRE-DAWN HOURS AND A SLIGHT CHANCE OF RAIN FOR SC INTO DAWN.
MINIMUMS LOW/MID 40S INLAND...AND UPPER 40S TO NEAR 50 COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...MID-LEVEL IMPULSE MOVING OVERHEAD FRIDAY
WILL COMBINE WITH INCREASING ISENTROPIC LIFT ALONG THE 300K SURFACE
ATOP A SURFACE WEDGE OF HIGH PRESSURE TO CREATE CLOUDS AND SHOWERS
DURING THE AFTERNOON. THERE CONTINUES UNCERTAINTY INTO HOW
SIGNIFICANT THE QPF WILL BE FROM THIS SETUP...AND GUIDANCE HAS
CONTINUED TO BACK OFF ON TOTAL RAINFALL FORECASTS ON FRIDAY. 700MB
OMEGAS ARE FOCUSED JUST OFFSHORE...COINCIDENT WITH THE BEST
PVA...WHILE ISENTROPIC LIFT NEVER BECOMES VERY STRONG OR STEEP. THIS
SUGGESTS THERE MAY BE PERIODS OF VERY LIGHT SHOWERS FRIDAY
AFTN...WITH SOME BETTER RAIN POSSIBLY JUST OFF THE COAST. THIS
MATCHES WELL WITH WPC QPF GRAPHICS FOR FRIDAY...AND AND HESITANT
TO INCREASE POP ANYTHING ABOVE THE INHERITED LOW-CHC. FRIDAY WILL
NOT BE A VERY NICE DAY...AND THE MAV TEMPS HAVE STEADILY WALKED BACK
TOWARDS THE COOLER ECS/MET NUMBERS WHICH SUPPORT THE STRONGER WEDGE.
WITH MID-LEVEL RIDGING AMPLIFYING TO THE EAST PRODUCING INCREASING
SW FLOW ALOFT...STILL BELIEVE THE MET/ECS CAMP IS TOO LOW...BUT WILL
LOWER HIGHS FRIDAY 1-2 DEGREES ACROSS THE BOARD. LIFT AND FORCING
MOVE OFF TO THE NE FRIDAY NIGHT...LEAVING IMPROVING CONDITIONS WITH
LOWS IN THE MID AND UPR 40S.
SATURDAY REMAINS A TRICKIER FORECAST DUE TO THE APPROACH OF A LOW
PRESSURE FROM THE SW AND THE PASSAGE OF A WARM FRONT SATURDAY AFTN.
THE GUIDANCE HAS SPED UP TIMING OF FEATURES EMBEDDED WITHIN STRONG
SW MID-LEVEL FLOW...AND THIS HAS CREATED A CLOUDIER...AND
RAINIER...SATURDAY FORECAST. LOW PRESSURE WILL MOVE NEAR THE SPINE
OF THE APPALACHIANS...BUT ITS WARM FRONT WILL LIFT NORTH ACROSS THE
CWA SATURDAY AFTN. THIS BRINGS RAPIDLY WARMING TEMPERATURES...AND
HIGHS SATURDAY WILL CLIMB WELL INTO THE 60S...AND MAY APPROACH 70 IN
THE EASTERN ZONES DEPENDING ON CLOUD COVER. INCREASING RAIN CHANCES
WILL ALSO ACCOMPANY THIS BOUNDARY...ESPECIALLY SATURDAY NIGHT.
STRONG LLJ NOSES INTO THE REGION AHEAD OF THE COLD FRONT SATURDAY
NIGHT...SO AS NOTED BY PREVIOUS FORECASTER...SHOWERS COULD BECOME
GUSTY LATE IN THE PERIOD...ALTHOUGH INSTABILITY IS LACKING. BY
SUNDAY MORNING THE COLD FRONT ASSOCIATED WITH THE LOW MOVING
NORTHEAST WILL BE ON THE DOORSTEP TO THE CWA. LOWS SATURDAY NIGHT
WILL REMAIN VERY WARM...MID 50S...AS THE WARM SECTOR PERSISTS
LOCALLY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...LINGERING SHOWERS EARLY SUNDAY WILL RAPIDLY
DISSIPATE AS A COLD FRONT CROSSES THE AREA SUNDAY MORNING AND PRECIP
EJECTS OFF TO THE NORTHEAST. THIS IS A TRUE ARCTIC FRONT...AND
STRONG COLD ADVECTION WILL FOLLOW AFTER A WARM FIRST PART OF SUNDAY.
AN ATYPICAL DIURNAL CURVE IS PROBABLE SUNDAY...BUT HIGHS SUNDAY
WILL LIKELY STILL BE ABOUT 10 DEGREES ABOVE NORMAL THANKS TO THE
EARLY MORNING WARM TEMPERATURES.
THEREAFTER...A RETURN TO SEASONABLE OR EVEN BELOW SEASONABLE
TEMPERATURES IS FORECAST. NOT ONLY IS STRONG CAA EXPECTED SUNDAY
NIGHT THROUGH TUESDAY AS 850MB TEMPS FALL TO AROUND -2C...BUT
TELECONNECTIONS SUPPORT AN INTRUSION OF COLD AIR ALONG THE EAST
COAST AS THE AO INDEX PLUMMETS TO SHARPLY NEGATIVE VALUES. ALTHOUGH
THE SUN ANGLE IS SLOWLY INCREASING...INSOLATION WILL NOT BE ABLE TO
OVERCOME THE VERY COLD AIR MASS...SO TEMPS MONDAY THROUGH WEDNESDAY
WILL LIKELY REMAIN BELOW CLIMO...COLDEST WEDNESDAY AS A REINFORCING
SHOT OF COLD AIR /DRY FRONT/ CROSSES THE AREA TUESDAY. THE GFS HAS
THIS FRONT STALLING OFFSHORE WED AS A WAVE OF LOW PRESSURE MOVES UP
ALONG IT...BRINGING SLIGHTLY WARMER TEMPERATURES AND INCREASING RAIN
CHANCES. THIS IS AN INDEPENDENT SOLUTION ATTM HOWEVER...AND WILL OPT
TO SHOW CONTINUED DRY WEATHER WITH BELOW NORMAL TEMPS THROUGH
WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...IFR CONDITIONS WILL BE SETTING UP SHORTLY WITH MAINLY
MVFR/VFR VISIBILITIES. HIGH PRESSURE WILL CONTINUE TO RIDGE JUST
WEST OF THE CWA. THE HRRR MODEL KEEPS ANY PRECIP OFFSHORE AT THIS
TIME...BUT COULD NOT RULE OUT A SPRINKLE AT THE COASTAL TERMINALS
TOWARD MORNING. THURSDAY...A GRADUAL IMPROVEMENT IS FORECAST WITH
CLOUDS SCATTERING IN THE AFTERNOON...ONLY TO RETURN AS STRATUS
SHORTLY AFTER DARK.
EXTENDED OUTLOOK...POTENTIAL FOR MVFR IN SHOWERS FRIDAY
AND EARLY SUNDAY. OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM THURSDAY...SEA SPECTRUM STILL A BIT UGLY AND A HAZARD
TO SMALL CRAFT...AS HIGH PRESSURE INLAND AND LOW PRESSURE MOVING
NORTH OUT OF THE BAHAMA CHAIN INTERACT TO PRODUCE NNE WINDS 20-25
KT TODAY INTO TONIGHT. SEA HEIGHTS WILL HOLD AT 4-6 FT AND NEAR 7
FT FAR OUTER WATERS WITH DOMINANT PERIODS BETWEEN 6-8 SECONDS.
SEAS MESSY SINCE SE WAVE ENERGY IS CO-MINGLING WITH THE N WAVES.
NO TSTMS ON THE 0-20 NM WATERS BUT A FEW SHOWERS CAN BE EXPECTED
OUTER WATERS MOVING FROM NE TO SW AT 25 KT. ONLY A SLIGHT EASING
OF WIND EXPECTED TONIGHT AS THE LOW OFFSHORE MOVES FARTHER N. SEAS
WILL NEED TIME TO RECOVER AND ITS POSSIBLE THE ADVISORY COULD BE
EXTENDED THIS EVENING OR EVEN OVERNIGHT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WEDGE OF HIGH PRESSURE WILL SLOWLY WEAKEN
INLAND FROM THE WATERS...CAUSING NE WINDS TO SLOWLY FALL OFF
DURING FRIDAY FROM AROUND 15 KTS EARLY TO 10 KTS LATE. WHILE THIS
WILL PERSIST THE PROLONGED NE FETCH...THE FALLING WINDS WILL HELP
SEAS DROP SLOWLY ON FRIDAY. INITIALLY...3-5 FTERS WILL BE COMMON
WITH A FEW 6 FT SEAS STILL POSSIBLE ESPECIALLY ACROSS NC
WATERS...BUT CONFIDENCE NOT HIGH ENOUGH ATTM TO EXTEND SCA INTO
FRIDAY...AND WILL INSTEAD NOTE HERE AND HWO IT MAY BE REQUIRED.
ANY HEADLINES WILL DROP FRIDAY NIGHT AS SEAS FALL TO 3-4 FT.
ON SATURDAY...A WARM FRONT WILL LIFT NORTH ACROSS THE WATERS CAUSING
WINDS TO SHIFT TO THE SE AND THEN TO THE SW LATE SATURDAY.
ACCOMPANYING THIS WIND SHIFT WILL BE A STEADY INCREASE IN SPEED TO
AROUND 20 KTS LATE IN THE DAY AND AT NIGHT. THIS WILL DRIVE WAVE
HEIGHTS ONCE AGAIN UP TO SCA THRESHOLDS OF 4-7 FT...AND RENEWED
HEADLINES ARE LIKELY LATE IN THE PERIOD.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SUNDAY BEGINS WITH GUSTY SW WINDS AROUND
20 KTS ONGOING ACROSS THE WATERS AHEAD OF A COLD FRONT WHICH WILL
CROSS OFFSHORE SUNDAY EVENING. THESE ENHANCED WINDS WILL CREATE
SEAS OF 4- 7 FT...AND AN SCA WILL LIKELY BE IN EFFECT TO START THE
PERIOD. WITH THE FROPA WILL BE A RAPID WIND SHIFT TO THE NW BUT
WITH SPEEDS REMAINING AT 15-20 KTS SUNDAY NIGHT...BEFORE SLOWLY
FALLING TO AROUND 10 KTS MONDAY WITH A STILL NW DIRECTION.
HEADLINES WILL DROP QUICKLY BEHIND THE FRONT AS THE NW WINDS PUSH
THE HIGHEST SEAS OUT OF THE LOCAL WATERS...AND WAVE HEIGHTS ARE
EXPECTED TO FALL TO 3-5 FT SUNDAY NIGHT...AND THEN FURTHER TO 2-3
FT DURING MONDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC
MARINE...MJC/JDW
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1004 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 1004 AM CST THU JAN 7 2016
WATER VAPOR LOOP INDICATED A WEAK UPPER TROUGH OVER CENTRAL ND AND
WAS MOVING EAST. 3 G/KG MIXING RATIOS WERE OVER THE SOUTHEAST ZONES
AND PRECIPITABLE WATER WAS AROUND HALF AN INCH OVER THE
SOUTH/SOUTHEAST ZONES. SURFACE LOW WAS SOUTHEAST OF ABR AND IS
FORECAST TO MOVE NORTHEAST TODAY. RADAR CONTINUES TO SHOW PRECIP
ACCUMULATING OVER SOUTHERN ZONES. WILL KEEP CURRENT ADVISORIES AND
WARNINGS GOING.
UPDATE ISSUED AT 639 AM CST THU JAN 7 2016
SNOW BAND CONTINUES TO EXPAND NORTHEASTWARD...WITH MORE RETURNS
DEVELOPING BACK TO THE SOUTHEAST. SHORT RANGE MODELS CONTINUE TO
KEEP SOME DECENT QPF OVER THE CWA THROUGH THE REST OF THE MORNING.
AND THERE WILL BE FREEZING DRIZZLE LINGERING A BIT LONGER IN SOME
AREAS. WILL EXTEND THE HEADLINES UNTIL 18Z. MAY NEED TO GO LONGER
IF THE HRRR VERIFIES BUT FOR NOW JUST KEEP IT GOING THROUGH THE
NEXT SIX HOURS AND SEE HOW THINGS DEVELOP. ALSO EXPANDED THE
WARNING UP INTO MAHNOMEN...EASTERN POLK...AND NORTHERN CLEARWATER
COUNTIES AS THE BAND MOVES NORTHEAST AND PULLED TRAILL BACK DOWN
TO ADVISORY AS IT SEEMS THE HEAVIEST AMOUNTS HAVE MISSED THEM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
WHAT HAPPENS WITH THE MESOSCALE SNOW BAND AND WHAT TO DO WITH
HEADLINES WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM.
WEAK SHORTWAVE TROUGH MOVING THROUGH ND...WITH A SFC LOW OVER
NORTH CENTRAL SD. THE MESOSCALE SNOW BAND OVER THE SOUTHERN RED
RIVER VALLEY HAS CONTINUED TO SLOWLY MOVE SOUTHEAST. THE
MID LEVEL FRONTOGENESIS DOES NOT LOOK ALL THAT STRONG WHERE THE
BAND IS LOCATED...BUT WITH NEGATIVE EPV AND HIGH MID LEVEL LAPSE
RATES THERE HAS BEEN ENOUGH INSTABILITY TO GET A NARROW AREA OF
HEAVY SNOW. WHERE THE BEST FRONTOGENSIS IS LOCATED OVER THE
NORTHWESTERN CWA A BAND TRIED TO GET GOING...BUT SEEMS TO BE
DISSIPATING LAST FEW SCANS. THERE HAS BEEN A REPORT OF 6 PLUS
INCHES IN CASSELTON SO THE WARNING SEEMS TO BE ON TRACK. THE HOP
WRF...RAP...AND HRRR ALL HAVE A NARROW BAND OF HIGH SNOW
ACCUMULATION EXTENDING FROM CENTRAL CASS COUNTY UP INTO THE
CLAY/NORMAN AREA. THERE ARE HINTS THAT THE HEAVY SNOW COULD EXTEND
FURTHER NORTHEAST...AND THERE HAS BEEN SOME FAIRLY HEAVY RADAR
RETURNS IN NORTHEASTERN MAHNOMEN COUNTY CURRENTLY. GIVEN THAT THE
EPV AND LAPSE RATES SLOWLY BECOME A BIT LESS FAVORABLE GOING INTO
TODAY...AM NOT SURE HOW LONG THE BAND WILL BE PRODUCING 2 PLUS PER
HOUR SNOWFALL RATES. HAVE THE HEAVY SNOW BAND IN THE GRIDS
EXTENDING INTO THE FAR CORNER OF MAHNOMEN...BUT WILL KEEP THE
HEADLINES AS THEY ARE FOR NOW AND REEVALUATE WHEN WE GET A BIT
MORE GROUND TRUTH LATER THIS MORNING.
THE OTHER ISSUE WILL BE FREEZING DRIZZLE. THE PKD ASOS CONTINUES
TO REPORT AN I GROUP AT TIMES...AND MODEL SOUNDING ACROSS MUCH OF
THE CWA SHOW A DRY LAYER ALOFT EXCEPT WHEN THE SNOW BAND IS
GOING THROUGH. WILL CONTINUE TO KEEP A FREEZING DRIZZLE MENTION
THROUGH THE REST OF THE MORNING AND WILL KEEP THE ADVISORY GOING
IN THE SOUTH FOR THAT REASON. THERE ARE SOME SIGNS OF DRIER AIR
ALOFT COMING IN TONIGHT...PARTICULARLY IN THE WESTERN COUNTIES AS
COLDER AIR COMES DOWN THE BACKSIDE OF THE SFC LOW. WILL INCLUDE A
SLIGHT CHANCE OF FREEZING DRIZZLE MENTION FOR TONIGHT...FOLLOWING
WHERE THE MODELS HAVE THE LOWER CHANCES OF ICE CRYSTALS IN THE
CLOUD.
LIGHT SNOW WILL ALSO CONTINUE AT TIMES AS THE MAIN UPPER
TROUGH DIGS DOWN OUT OF CANADA ON FRIDAY. DO NOT THINK THERE WILL
BE VERY MUCH ACCUMULATION...BUT KEPT SOME CHANCE POPS FOR UP TO
HALF AN INCH OF ACCUMULATION. THE ARCTIC AIR WILL START BUILDING
DOWN INTO THE NORTHERN PLAINS FRIDAY. MODELS HAVE 925MB
TEMPERATURES DOWN TO -20 C BY LATE AFTERNOON. THINK THAT READINGS
WILL FALL THROUGHOUT THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
FRIDAY NIGHT THROUGH SATURDAY NIGHT...ARCTIC HIGH PRESSURE PARKS
ITSELF OVER THE NORTHERN PLAINS. THINK THAT THERE MAY BE A BIT OF
LIGHT SNOW LINGERING OVER THE NORTHEAST INTO FRIDAY NIGHT...BUT
OTHERWISE THERE WILL BE CLEARING OUT AND COLD THROUGH THE PERIOD.
TEMPS WILL BE BELOW ZERO EVEN INTO SATURDAY AFTERNOON...AND COULD
DROP DOWN TO THE 15 TO 20 BELOW RANGE SATURDAY NIGHT. WIND CHILLS
WILL ALSO MAKE IT SEEM EVEN COLDER.
SUNDAY-WEDNESDAY...BELOW AVE TEMPS WILL CONTINUE TO BE THE THEME
DURING THIS TIME. ANOTHER COLD DAY IS EXPECTED FOR SUNDAY...EVEN AS
THE COLDEST 850 MB TEMPS SHIFT EAST AND THE SFC HIGH DROPS SOUTH OF
REGION. THE NEXT ARCTIC FRONT LOOKS TO SWEEP THROUGH AROUND
MONDAY...REINFORCING THE COLD AIR THROUGH THE EARLY PART OF THE
WEEK. CURRENTLY HAVE THE EARLY WEEK PERIOD DRY...BUT THE 00Z
GFS/ECMWF DO SHOW A CLIPPER SYSTEM MOVING SOUTH WITH THE ARCTIC AIR
MONDAY...WITH SOME POTENTIAL FOR LIGHT SNOW. SOME MODERATION IN
TEMPS IS POSSIBLE BY MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 639 AM CST THU JAN 7 2016
IFR CONDITIONS AT MOST LOCATIONS ALTHOUGH A FEW SPOTS HAVE TRIED
TO GO UP TO MVFR. THINK THAT THE LOWER STRATUS WILL HANG AROUND
FOR MUCH OF THE DAY AND KEPT IFR AND LOWER CIGS THROUGH THE END OF
THE TAF PERIOD. VIS WILL BE DIFFICULT WITH SNOW MOVING THROUGH.
HEAVIER SNOW IS STILL SEEN ON RADAR APPROACHING KFAR...SO INCLUDED
A TEMPO GROUP FOR SOME SUB 1SM VIS FOR A SHORT TIME...BUT
OTHERWISE MOST SITES WILL BE MOSTLY IN THE 2-5SM RANGE WITH BRIEF
VIS REDUCTIONS DOWN TO 1SM. BY THIS EVENING THE HEAVIER BANDS WILL
DISSIPATE BUT THERE COULD BE SOME VERY LIGHT SNOW OR FLURRIES
HANGING AROUND AND KEEPING VIS DOWN AT SOME SPOTS. WINDS WILL BE
GENERALLY OUT OF THE NORTH AT LESS THAN 12 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NDZ028>030-038-
049-052-053.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR NDZ039.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ001-009-013-
014-017-023-024-027>032-040.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ002-003-015-016-
022.
&&
$$
UPDATE...HOPPES
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
945 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 904 AM CST THU JAN 7 2016
MAIN AREA OF SNOW THAT WAS AFFECTING DICKEY AND LAMOURE COUNTIES HAS
PUSHED TO THE EAST WITH ONLY SOME LIGHT SNOW REMAINING.
THEREFORE...HAVE LET ADVISORY EXPIRE. TO THE NORTH...A WEAK WAVE
MOVING THROUGH IS PRODUCING SOME VERY LIGHT SNOW SO HAVE ADDED
SOME LOW POPS ALONG THE CANADIAN BORDER. OTHERWISE...PREVIOUS
FORECAST WAS IN GOOD SHAPE AND HAD THE FOG AND FREEZING DRIZZLE
ADDRESSED WELL.
UPDATE ISSUED AT 641 AM CST THU JAN 7 2016
EXPANDED THE MENTION OF LIGHT FREEZING DRIZZLE TO ALL OF SOUTH
CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY THIS
MORNING...THROUGH TONIGHT BASED UPON THE NDDOT TRAVEL MAP AS OF 12
UTC...AND 11 UTC RAP SOUNDINGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU JAN 7 2016
THE MAIN FOCUS FOR TODAY AND TONIGHT IS FREEZING PRECIPITATION.
AN UPPER LEVEL SHORTWAVE CENTERED OVER NORTH DAKOTA...AN INVERTED
SURFACE TROUGH NOSING INTO THE EASTERN DAKOTAS AND MOIST UPSLOPE
FLOW WERE PROVIDING AMPLE LIFT FOR PRECIPITATION DEVELOPMENT THIS
MORNING.
AREAS OF LIGHT SNOW AND FREEZING DRIZZLE CONTINUE TO DEVELOP
ACROSS THE SOUTHERN JAMES VALLEY. PRECIPITATION WILL LIKELY
CONTINUE THERE FOR THE NEXT SEVERAL HOURS AND CLEAR OUT BY THE
LATE MORNING HOURS AS THE WAVE SHIFTS EAST. ONLY MINOR
ACCUMULATIONS OF SNOW ARE EXPECTED (GENERALLY LESS THAN ONE HALF
INCH)...HOWEVER...SOUNDINGS FAVOR A FREEZING DRIZZLE MODE FOR AN
EXTENDED PERIOD OF TIME. THIS MAY LEAD TO A THIN GLAZE OF ICE.
AFTER THE WAVE PUSHES EAST THIS MORNING...ANOTHER WAVE IS EXPECTED
TO ENTER THE AREA TONIGHT. WITH PLENTY OF LOW LEVEL MOISTURE
REMAINING THIS WILL PROVIDE THE LIFT NECESSARY TO REDEVELOP
PRECIPITATION. FREEZING DRIZZLE IS FAVORED ACROSS SOUTH CENTRAL
NORTH DAKOTA AS SLIGHTLY WARMER TEMPERATURES ALOFT ARE FORECAST TO
LEAD TO AN UNSATURATED DENDRITIC GROWTH ZONE. FURTHER WEST AND
NORTH COOLER AIR SHOULD KEEP PRECIPITATION IN THE FORM OF ALL
SNOW. ONLY MINOR ACCUMULATIONS ARE EXPECTED...GENERALLY AN INCH
OR LESS ACROSS PORTIONS OF NORTHERN AND WESTERN NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU JAN 7 2016
TWO ARCTIC AIRMASSES AND DANGEROUS WIND CHILLS HIGHLIGHT THE
EXTENDED FORECAST.
PRIOR TO THE ARRIVAL OF THE FIRST ARCTIC AIRMASS...THE 00 AND
INCOMING 06 UTC NAM AND GFS BUFR SOUNDINGS SUPPORT THE POTENTIAL
FOR FREEZING DRIZZLE ACROSS MUCH OF CENTRAL NORTH DAKOTA FRIDAY
MORNING WITH LOW LEVEL SATURATION WARMER THAN -10 C AND A LACK OF
ICE CRYSTALS IN THE COLUMN.
THEREAFTER...THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES
CONTINUE TO SHOW GOOD AGREEMENT ON TWO POSSIBLE ARCTIC AIRMASSES
TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA. THE FIRST...ARRIVING
THROUGH THE DAY ON FRIDAY AND REMAINING IN PLACE THROUGH THE
WEEKEND...WITH A POSSIBLE SECOND SURGE OF ARCTIC AIR MONDAY INTO
TUESDAY. WIDESPREAD DANGEROUS WIND CHILLS AS LOW AS 35 BELOW ARE
FORECAST DURING THE MORNING AND NIGHTTIME HOURS OF SATURDAY AND
SUNDAY. A WIND CHILL ADVISORY WILL LIKELY BE NEEDED THIS WEEKEND.
OVERALL...THE WIND FIELD WITH THE POSSIBLE SECOND SURGE OF ARCTIC
AIR IS STRONGER WHEN COMPARED TO THE FIRST...WHICH MAY INTRODUCE A
BLOWING SNOW THREAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 641 AM CST THU JAN 7 2016
IFR AND LIFR IN STRATUS AND FOG WILL PREVAIL AT ALL SITES THROUGH
TODAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. FREEZING DRIZZLE IS
POSSIBLE AT KBIS AND KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...AJ
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
646 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 641 AM CST THU JAN 7 2016
EXPANDED THE MENTION OF LIGHT FREEZING DRIZZLE TO ALL OF SOUTH
CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY THIS
MORNING...THROUGH TONIGHT BASED UPON THE NDDOT TRAVEL MAP AS OF 12
UTC...AND 11 UTC RAP SOUNDINGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU JAN 7 2016
THE MAIN FOCUS FOR TODAY AND TONIGHT IS FREEZING PRECIPITATION.
AN UPPER LEVEL SHORTWAVE CENTERED OVER NORTH DAKOTA...AN INVERTED
SURFACE TROUGH NOSING INTO THE EASTERN DAKOTAS AND MOIST UPSLOPE
FLOW WERE PROVIDING AMPLE LIFT FOR PRECIPITATION DEVELOPMENT THIS
MORNING.
AREAS OF LIGHT SNOW AND FREEZING DRIZZLE CONTINUE TO DEVELOP
ACROSS THE SOUTHERN JAMES VALLEY. PRECIPITATION WILL LIKELY
CONTINUE THERE FOR THE NEXT SEVERAL HOURS AND CLEAR OUT BY THE
LATE MORNING HOURS AS THE WAVE SHIFTS EAST. ONLY MINOR
ACCUMULATIONS OF SNOW ARE EXPECTED (GENERALLY LESS THAN ONE HALF
INCH)...HOWEVER...SOUNDINGS FAVOR A FREEZING DRIZZLE MODE FOR AN
EXTENDED PERIOD OF TIME. THIS MAY LEAD TO A THIN GLAZE OF ICE.
AFTER THE WAVE PUSHES EAST THIS MORNING...ANOTHER WAVE IS EXPECTED
TO ENTER THE AREA TONIGHT. WITH PLENTY OF LOW LEVEL MOISTURE
REMAINING THIS WILL PROVIDE THE LIFT NECESSARY TO REDEVELOP
PRECIPITATION. FREEZING DRIZZLE IS FAVORED ACROSS SOUTH CENTRAL
NORTH DAKOTA AS SLIGHTLY WARMER TEMPERATURES ALOFT ARE FORECAST TO
LEAD TO AN UNSATURATED DENDRITIC GROWTH ZONE. FURTHER WEST AND
NORTH COOLER AIR SHOULD KEEP PRECIPITATION IN THE FORM OF ALL
SNOW. ONLY MINOR ACCUMULATIONS ARE EXPECTED...GENERALLY AN INCH
OR LESS ACROSS PORTIONS OF NORTHERN AND WESTERN NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU JAN 7 2016
TWO ARCTIC AIRMASSES AND DANGEROUS WIND CHILLS HIGHLIGHT THE
EXTENDED FORECAST.
PRIOR TO THE ARRIVAL OF THE FIRST ARCTIC AIRMASS...THE 00 AND
INCOMING 06 UTC NAM AND GFS BUFR SOUNDINGS SUPPORT THE POTENTIAL
FOR FREEZING DRIZZLE ACROSS MUCH OF CENTRAL NORTH DAKOTA FRIDAY
MORNING WITH LOW LEVEL SATURATION WARMER THAN -10 C AND A LACK OF
ICE CRYSTALS IN THE COLUMN.
THEREAFTER...THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES
CONTINUE TO SHOW GOOD AGREEMENT ON TWO POSSIBLE ARCTIC AIRMASSES
TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA. THE FIRST...ARRIVING
THROUGH THE DAY ON FRIDAY AND REMAINING IN PLACE THROUGH THE
WEEKEND...WITH A POSSIBLE SECOND SURGE OF ARCTIC AIR MONDAY INTO
TUESDAY. WIDESPREAD DANGEROUS WIND CHILLS AS LOW AS 35 BELOW ARE
FORECAST DURING THE MORNING AND NIGHTTIME HOURS OF SATURDAY AND
SUNDAY. A WIND CHILL ADVISORY WILL LIKELY BE NEEDED THIS WEEKEND.
OVERALL...THE WIND FIELD WITH THE POSSIBLE SECOND SURGE OF ARCTIC
AIR IS STRONGER WHEN COMPARED TO THE FIRST...WHICH MAY INTRODUCE A
BLOWING SNOW THREAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 641 AM CST THU JAN 7 2016
IFR AND LIFR IN STRATUS AND FOG WILL PREVAIL AT ALL SITES THROUGH
TODAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. FREEZING DRIZZLE IS
POSSIBLE AT KBIS AND KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ048-
051.
&&
$$
UPDATE...AYD
SHORT TERM...AJ
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
639 AM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 639 AM CST THU JAN 7 2016
SNOW BAND CONTINUES TO EXPAND NORTHEASTWARD...WITH MORE RETURNS
DEVELOPING BACK TO THE SOUTHEAST. SHORT RANGE MODELS CONTINUE TO
KEEP SOME DECENT QPF OVER THE CWA THROUGH THE REST OF THE MORNING.
AND THERE WILL BE FREEZING DRIZZLE LINGERING A BIT LONGER IN SOME
AREAS. WILL EXTEND THE HEADLINES UNTIL 18Z. MAY NEED TO GO LONGER
IF THE HRRR VERIFIES BUT FOR NOW JUST KEEP IT GOING THROUGH THE
NEXT SIX HOURS AND SEE HOW THINGS DEVELOP. ALSO EXPANDED THE
WARNING UP INTO MAHNOMEN...EASTERN POLK...AND NORTHERN CLEARWATER
COUNTIES AS THE BAND MOVES NORTHEAST AND PULLED TRAILL BACK DOWN
TO ADVISORY AS IT SEEMS THE HEAVIEST AMOUNTS HAVE MISSED THEM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
WHAT HAPPENS WITH THE MESOSCALE SNOW BAND AND WHAT TO DO WITH
HEADLINES WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM.
WEAK SHORTWAVE TROUGH MOVING THROUGH ND...WITH A SFC LOW OVER
NORTH CENTRAL SD. THE MESOSCALE SNOW BAND OVER THE SOUTHERN RED
RIVER VALLEY HAS CONTINUED TO SLOWLY MOVE SOUTHEAST. THE
MID LEVEL FRONTOGENESIS DOES NOT LOOK ALL THAT STRONG WHERE THE
BAND IS LOCATED...BUT WITH NEGATIVE EPV AND HIGH MID LEVEL LAPSE
RATES THERE HAS BEEN ENOUGH INSTABILITY TO GET A NARROW AREA OF
HEAVY SNOW. WHERE THE BEST FRONTOGENSIS IS LOCATED OVER THE
NORTHWESTERN CWA A BAND TRIED TO GET GOING...BUT SEEMS TO BE
DISSIPATING LAST FEW SCANS. THERE HAS BEEN A REPORT OF 6 PLUS
INCHES IN CASSELTON SO THE WARNING SEEMS TO BE ON TRACK. THE HOP
WRF...RAP...AND HRRR ALL HAVE A NARROW BAND OF HIGH SNOW
ACCUMULATION EXTENDING FROM CENTRAL CASS COUNTY UP INTO THE
CLAY/NORMAN AREA. THERE ARE HINTS THAT THE HEAVY SNOW COULD EXTEND
FURTHER NORTHEAST...AND THERE HAS BEEN SOME FAIRLY HEAVY RADAR
RETURNS IN NORTHEASTERN MAHNOMEN COUNTY CURRENTLY. GIVEN THAT THE
EPV AND LAPSE RATES SLOWLY BECOME A BIT LESS FAVORABLE GOING INTO
TODAY...AM NOT SURE HOW LONG THE BAND WILL BE PRODUCING 2 PLUS PER
HOUR SNOWFALL RATES. HAVE THE HEAVY SNOW BAND IN THE GRIDS
EXTENDING INTO THE FAR CORNER OF MAHNOMEN...BUT WILL KEEP THE
HEADLINES AS THEY ARE FOR NOW AND REEVALUATE WHEN WE GET A BIT
MORE GROUND TRUTH LATER THIS MORNING.
THE OTHER ISSUE WILL BE FREEZING DRIZZLE. THE PKD ASOS CONTINUES
TO REPORT AN I GROUP AT TIMES...AND MODEL SOUNDING ACROSS MUCH OF
THE CWA SHOW A DRY LAYER ALOFT EXCEPT WHEN THE SNOW BAND IS
GOING THROUGH. WILL CONTINUE TO KEEP A FREEZING DRIZZLE MENTION
THROUGH THE REST OF THE MORNING AND WILL KEEP THE ADVISORY GOING
IN THE SOUTH FOR THAT REASON. THERE ARE SOME SIGNS OF DRIER AIR
ALOFT COMING IN TONIGHT...PARTICULARLY IN THE WESTERN COUNTIES AS
COLDER AIR COMES DOWN THE BACKSIDE OF THE SFC LOW. WILL INCLUDE A
SLIGHT CHANCE OF FREEZING DRIZZLE MENTION FOR TONIGHT...FOLLOWING
WHERE THE MODELS HAVE THE LOWER CHANCES OF ICE CRYSTALS IN THE
CLOUD.
LIGHT SNOW WILL ALSO CONTINUE AT TIMES AS THE MAIN UPPER
TROUGH DIGS DOWN OUT OF CANADA ON FRIDAY. DO NOT THINK THERE WILL
BE VERY MUCH ACCUMULATION...BUT KEPT SOME CHANCE POPS FOR UP TO
HALF AN INCH OF ACCUMULATION. THE ARCTIC AIR WILL START BUILDING
DOWN INTO THE NORTHERN PLAINS FRIDAY. MODELS HAVE 925MB
TEMPERATURES DOWN TO -20 C BY LATE AFTERNOON. THINK THAT READINGS
WILL FALL THROUGHOUT THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
FRIDAY NIGHT THROUGH SATURDAY NIGHT...ARCTIC HIGH PRESSURE PARKS
ITSELF OVER THE NORTHERN PLAINS. THINK THAT THERE MAY BE A BIT OF
LIGHT SNOW LINGERING OVER THE NORTHEAST INTO FRIDAY NIGHT...BUT
OTHERWISE THERE WILL BE CLEARING OUT AND COLD THROUGH THE PERIOD.
TEMPS WILL BE BELOW ZERO EVEN INTO SATURDAY AFTERNOON...AND COULD
DROP DOWN TO THE 15 TO 20 BELOW RANGE SATURDAY NIGHT. WIND CHILLS
WILL ALSO MAKE IT SEEM EVEN COLDER.
SUNDAY-WEDNESDAY...BELOW AVE TEMPS WILL CONTINUE TO BE THE THEME
DURING THIS TIME. ANOTHER COLD DAY IS EXPECTED FOR SUNDAY...EVEN AS
THE COLDEST 850 MB TEMPS SHIFT EAST AND THE SFC HIGH DROPS SOUTH OF
REGION. THE NEXT ARCTIC FRONT LOOKS TO SWEEP THROUGH AROUND
MONDAY...REINFORCING THE COLD AIR THROUGH THE EARLY PART OF THE
WEEK. CURRENTLY HAVE THE EARLY WEEK PERIOD DRY...BUT THE 00Z
GFS/ECMWF DO SHOW A CLIPPER SYSTEM MOVING SOUTH WITH THE ARCTIC AIR
MONDAY...WITH SOME POTENTIAL FOR LIGHT SNOW. SOME MODERATION IN
TEMPS IS POSSIBLE BY MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 639 AM CST THU JAN 7 2016
IFR CONDITIONS AT MOST LOCATIONS ALTHOUGH A FEW SPOTS HAVE TRIED
TO GO UP TO MVFR. THINK THAT THE LOWER STRATUS WILL HANG AROUND
FOR MUCH OF THE DAY AND KEPT IFR AND LOWER CIGS THROUGH THE END OF
THE TAF PERIOD. VIS WILL BE DIFFICULT WITH SNOW MOVING THROUGH.
HEAVIER SNOW IS STILL SEEN ON RADAR APPROACHING KFAR...SO INCLUDED
A TEMPO GROUP FOR SOME SUB 1SM VIS FOR A SHORT TIME...BUT
OTHERWISE MOST SITES WILL BE MOSTLY IN THE 2-5SM RANGE WITH BRIEF
VIS REDUCTIONS DOWN TO 1SM. BY THIS EVENING THE HEAVIER BANDS WILL
DISSIPATE BUT THERE COULD BE SOME VERY LIGHT SNOW OR FLURRIES
HANGING AROUND AND KEEPING VIS DOWN AT SOME SPOTS. WINDS WILL BE
GENERALLY OUT OF THE NORTH AT LESS THAN 12 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NDZ028>030-038-
049-052-053.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR NDZ039.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ001-009-013-
014-017-023-024-027>032-040.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ002-003-015-016-
022.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...JR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
510 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
COMPLEX SCENARIO UNFOLDING WITH PRECIPITATION TYPES...ACCUMULATIONS
AND IMPACT. WATCHING THIS MORNING CLOSELY FOR ANY HINT OF IMPACT
FOR AN UPGRADE TO AN ADVISORY FOR FREEZING DRIZZLE...BECAUSE IT
IS OUT THERE OVER IOWA.
WATCHING SNOW MOVE THROUGH THE AREA AND BACK EDGE IS NEARING A
MSP-LSE-RFD LINE AT 09Z. BEHIND IT...REPORTS THROUGH CENTRAL IA
ARE DRIZZLE IS OCCURRING AND DEPENDING ON SURFACE
TEMPERATURES...ICING. WFO DES MOINES HAS HAD DRIZZLE FOR MANY
HOURS WITH ICING TO THE TREES BUT NOT THE GROUND LEVEL SURFACES.
THEY ALSO REPORT VSBY RESTRICTION IN IA MAINLY DUE TO DZ. ELEVATED
ICING SENSOR AT KDSM IS SHOWING SOME ICE ACCUMULATION. THIS
DRIZZLE AREA HAS A WELL FORECAST LEADING EDGE COINCIDENT WITH THE
IR CLOUD TOP WARMING REGION BEHIND THE SNOW ECHOES. KDSM HAS SEEN
-8C TO -10C CLOUD TOP TEMPS ALL NIGHT SUGGESTIVE OF AN ALL LIQUID
SURFACE-BASED SUPERCOOLED LAYER. THIS IS ALL SHIFTING INTO WI
WITH NO AIR MASS CHANGE THROUGH THE MORNING...AND LIGHT VERTICAL
MOTION IN THE 2KM DEEP SATURATED AND SUPERCOOLED LIQUID LAYER.
CALLS TO NERN IA SHERIFFS DO STATE THAT DRIZZLE IS HIT AND MISS
OUT THERE WITH SNOW COVERED ROADS. THE PROBLEM IS THEY ALSO SAID
THAT ICING IS OCCURRING ON ROAD SURFACES. HRRR AND RAP ARE
SUGGESTIVE WE WILL CONTINUE VERTICAL MOTION IN THE
LAYER...POSSIBLY TO -5 UB/S THROUGH THE MORNING...WITH A
DIMINISHING TREND AT LEAST FOR THE NORTH LATER THIS MORNING.
BELIEVE DRIZZLE AND FZDZ WILL BE AROUND THIS MORNING WITH VERY
LIGHT ACCUMULATIONS. WILL NEED TO UPGRADE SPS TO AN ADVISORY FOR
AT LEAST NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THE MORNING.
CANNOT BE SURE THIS DRIZZLE WILL BE ENDING THIS
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN FORECAST AREA AND THUS
LINGERED HIGHER PRECIPITATION CHANCES THERE ALL AFTERNOON...WITH A
SLIGHT BREAK TO THE NORTH.
LATER IN THE AFTERNOON AND TONIGHT WE SEE THE NEXT ROUND OF
PRECIPITATION MOVE IN FROM THE SOUTH ASSOCIATED WITH THE SHORTWAVE
TROUGH OVER TX AT 0930Z. THERE ARE NO REAL SURPRISES IN THIS
FORECAST AND VERY LITTLE CHANGE WAS MADE FROM LATER THURSDAY
THROUGH FRIDAY. A NICE RAIN/SNOW BAND IS EXPECTED AS MOISTURE
TRANSPORT CONVERGENCE ON THE NOSE OF THE LOW-LEVEL FLOW MOVES IN
LATE IN THE DAY WITH PRECIPITABLE WATER VALUES OVER 0.50 INCHES
WHICH IS ABOUT 200 PERCENT NORMAL. THIS FIRST BAND IS FAIRLY
TRANSIENT AND WITH THE OPEN WAVE ALOFT...DEFORMATION BANDING
DOESNT SEEN TO BE AN ISSUE...SO IT IS MULTIPLE SURGES OF WEAK-
MODERATE WARM ADVECTION WITHOUT UPPER LEVEL QVECTOR CONVERGENCE
SUPPORT...BUT IN THE MIDST OF ABUNDANT MOISTURE. SO...A
CLOUDY/RAINYSNOWY/DRIZZLY PERIOD.
HAVENT MOVED THE RAIN/SNOW LINE MUCH IN THIS FORECAST AND THE 1 TO
3 INCH SNOW ACCUMULATIONS STILL LOOK GOOD AND HIGHLY DEPEND ON
THE LOCATION AND TEMPERATURES. VALLEY LOCATIONS NORTH AND WEST OF
LA CROSSE WILL SEE THE LOWER END OF THOSE VALUES...WHILE COOLER
ELEVATED LOCATIONS AND NORTHCENTRAL WI NORTH OF HIGHWAY 29...WILL
GET THE HIGHER END. THIS SHOULD NOT BE MUCH OF AN IMPACT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
FRIDAY NIGHT AND SATURDAY...STILL SOME ACTIVE PRECIPITATION
CHANCES FRIDAY NIGHT AS THE ARCTIC FRONT COMES RIPPING IN. ALL
PRECIPITATION WILL CHANGE TO SNOW...AND COLD ADVECTION WILL BE
VERY NOTICEABLE FOR SATURDAY WITH FALLING TEMPERATURES AND WINDS
15 TO 25 MPH.
SUNDAY THROUGH WEDNESDAY...A COLD PERIOD WE HAVENT SEEN THIS
WINTER YET. IT IS STILL LOOKING LIKE WIND CHILL ADVISORIES WILL BE
NEEDED FOR SOME SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 510 AM CST THU JAN 7 2016
AS THE FIRST SHORT WAVE TROUGH MOVES AWAY FROM THE REGION...ICE IN
THE CLOUDS IS BEING LOST WHICH IS ALLOWING FOR SOME LIGHT FREEZING
DRIZZLE TO OCCUR. WITH THE FLOW REMAINING SOUTHWEST...SOME
ISENTROPIC UP GLIDE WILL CONTINUE THROUGH THE DAY FROM THE WARM
AIR ADVECTION. THIS WILL CREATE ENOUGH LIFT THROUGH THE SATURATED
LAYER TO KEEP THE FREEZING DRIZZLE GOING UNTIL TEMPERATURES WARM
TO ABOVE 0C AND SWITCH THIS OVER TO DRIZZLE. THE NEXT SHORT WAVE
TROUGH WILL APPROACH THE AREA TONIGHT AND GENERATE SOME BETTER
LIFT THROUGH THE COLUMN. THIS WILL ALSO CREATE A DEEPER SATURATED
LAYER AND ALLOW ICE TO BE REINTRODUCED INTO THE CLOUDS. THIS WILL
CHANGE THE DRIZZLE BACK OVER TO RAIN OR SNOW EARLY THIS
EVENING...BASED ON WHAT THE LOW LEVEL TEMPERATURES ARE. IT
CURRENTLY LOOKS LIKE KRST SHOULD BE COLD ENOUGH FOR MAINLY SNOW
WHILE KLSE WILL BE JUST A TOUCH WARMER FOR RAIN OR A RAIN SNOW
MIX. WITH ALL THIS PRECIPITATION...IFR CEILINGS WILL DOMINATE THE
PERIOD. THE VISIBILITY WILL BE MVFR TO IFR UNTIL THE HEAVIER
PRECIPITATION MOVES IN THIS EVENING WHEN BOTH SITES SHOULD HAVE
IFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR WIZ054-055-061.
MN...NONE.
IA...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
408 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
COMPLEX SCENARIO UNFOLDING WITH PRECIPITATION TYPES...ACCUMULATIONS
AND IMPACT. WATCHING THIS MORNING CLOSELY FOR ANY HINT OF IMPACT
FOR AN UPGRADE TO AN ADVISORY FOR FREEZING DRIZZLE...BECAUSE IT
IS OUT THERE OVER IOWA.
WATCHING SNOW MOVE THROUGH THE AREA AND BACK EDGE IS NEARING A
MSP-LSE-RFD LINE AT 09Z. BEHIND IT...REPORTS THROUGH CENTRAL IA
ARE DRIZZLE IS OCCURRING AND DEPENDING ON SURFACE
TEMPERATURES...ICING. WFO DES MOINES HAS HAD DRIZZLE FOR MANY
HOURS WITH ICING TO THE TREES BUT NOT THE GROUND LEVEL SURFACES.
THEY ALSO REPORT VSBY RESTRICTION IN IA MAINLY DUE TO DZ. ELEVATED
ICING SENSOR AT KDSM IS SHOWING SOME ICE ACCUMULATION. THIS
DRIZZLE AREA HAS A WELL FORECAST LEADING EDGE COINCIDENT WITH THE
IR CLOUD TOP WARMING REGION BEHIND THE SNOW ECHOES. KDSM HAS SEEN
-8C TO -10C CLOUD TOP TEMPS ALL NIGHT SUGGESTIVE OF AN ALL LIQUID
SURFACE-BASED SUPERCOOLED LAYER. THIS IS ALL SHIFTING INTO WI
WITH NO AIR MASS CHANGE THROUGH THE MORNING...AND LIGHT VERTICAL
MOTION IN THE 2KM DEEP SATURATED AND SUPERCOOLED LIQUID LAYER.
CALLS TO NERN IA SHERIFFS DO STATE THAT DRIZZLE IS HIT AND MISS
OUT THERE WITH SNOW COVERED ROADS. THE PROBLEM IS THEY ALSO SAID
THAT ICING IS OCCURRING ON ROAD SURFACES. HRRR AND RAP ARE
SUGGESTIVE WE WILL CONTINUE VERTICAL MOTION IN THE
LAYER...POSSIBLY TO -5 UB/S THROUGH THE MORNING...WITH A
DIMINISHING TREND AT LEAST FOR THE NORTH LATER THIS MORNING.
BELIEVE DRIZZLE AND FZDZ WILL BE AROUND THIS MORNING WITH VERY
LIGHT ACCUMULATIONS. WILL NEED TO UPGRADE SPS TO AN ADVISORY FOR
AT LEAST NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THE MORNING.
CANNOT BE SURE THIS DRIZZLE WILL BE ENDING THIS
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN FORECAST AREA AND THUS
LINGERED HIGHER PRECIPITATION CHANCES THERE ALL AFTERNOON...WITH A
SLIGHT BREAK TO THE NORTH.
LATER IN THE AFTERNOON AND TONIGHT WE SEE THE NEXT ROUND OF
PRECIPITATION MOVE IN FROM THE SOUTH ASSOCIATED WITH THE SHORTWAVE
TROUGH OVER TX AT 0930Z. THERE ARE NO REAL SURPRISES IN THIS
FORECAST AND VERY LITTLE CHANGE WAS MADE FROM LATER THURSDAY
THROUGH FRIDAY. A NICE RAIN/SNOW BAND IS EXPECTED AS MOISTURE
TRANSPORT CONVERGENCE ON THE NOSE OF THE LOW-LEVEL FLOW MOVES IN
LATE IN THE DAY WITH PRECIPITABLE WATER VALUES OVER 0.50 INCHES
WHICH IS ABOUT 200 PERCENT NORMAL. THIS FIRST BAND IS FAIRLY
TRANSIENT AND WITH THE OPEN WAVE ALOFT...DEFORMATION BANDING
DOESNT SEEN TO BE AN ISSUE...SO IT IS MULTIPLE SURGES OF WEAK-
MODERATE WARM ADVECTION WITHOUT UPPER LEVEL QVECTOR CONVERGENCE
SUPPORT...BUT IN THE MIDST OF ABUNDANT MOISTURE. SO...A
CLOUDY/RAINYSNOWY/DRIZZLY PERIOD.
HAVENT MOVED THE RAIN/SNOW LINE MUCH IN THIS FORECAST AND THE 1 TO
3 INCH SNOW ACCUMULATIONS STILL LOOK GOOD AND HIGHLY DEPEND ON
THE LOCATION AND TEMPERATURES. VALLEY LOCATIONS NORTH AND WEST OF
LA CROSSE WILL SEE THE LOWER END OF THOSE VALUES...WHILE COOLER
ELEVATED LOCATIONS AND NORTHCENTRAL WI NORTH OF HIGHWAY 29...WILL
GET THE HIGHER END. THIS SHOULD NOT BE MUCH OF AN IMPACT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
FRIDAY NIGHT AND SATURDAY...STILL SOME ACTIVE PRECIPITATION
CHANCES FRIDAY NIGHT AS THE ARCTIC FRONT COMES RIPPING IN. ALL
PRECIPITATION WILL CHANGE TO SNOW...AND COLD ADVECTION WILL BE
VERY NOTICEABLE FOR SATURDAY WITH FALLING TEMPERATURES AND WINDS
15 TO 25 MPH.
SUNDAY THROUGH WEDNESDAY...A COLD PERIOD WE HAVENT SEEN THIS
WINTER YET. IT IS STILL LOOKING LIKE WIND CHILL ADVISORIES WILL BE
NEEDED FOR SOME SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1140 PM CST WED JAN 6 2016
LIGHT SNOW WILL SWITCH OVER TO LIGHT FREEZING DRIZZLE OVERNIGHT
INTO EARLY THURSDAY MORNING. IFR TO LIFR CONDITIONS ARE EXPECTED.
THE FREEZING DRIZZLE LOOKS TO SWITCH OVER TO LIQUID DRIZZLE
THURSDAY MORNING AS TEMPERATURES WARM ABOVE FREEZING. KRST COULD
DROP TO VLIFR AT TIMES THURSDAY MORNING IN FOG. ANOTHER STORM
SYSTEM THEN MOVES IN THURSDAY AFTERNOON INTO THURSDAY EVENING WITH
A RAIN SNOW MIX EXPECTED...SWITCHING OVER TO MAINLY SNOW LATE
THURSDAY NIGHT. IFR TO LIFR CONDITIONS ARE EXPECTED IN THE SNOW
THURSDAY NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR WIZ054-055-061.
MN...NONE.
IA...FREEZING RAIN ADVISORY UNTIL NOON CST TODAY FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS TUCSON AZ
305 PM MST THU JAN 7 2016
.SYNOPSIS...WIDESPREAD RAIN AND SNOW...HEAVY SNOW IN THE
MOUNTAINS...WILL CONINTUE TONIGHT INTO FRIDAY. SHOWERS WILL DECREASE
FROM WEST TO EAST BY LATE FRIDAY NIGHT. A WEAKER SYSTEM WILL THEN
BRING A SLIGHT CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS
SUNDAY. OTHERWISE...DRY CONDITIONS WITH BELOW AVERAGE DAYTIME
TEMPERATURES WILL PREVAIL SATURDAY INTO THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...THE MAIN PRECIPITATION BAND WAS PASSING THROUGH
SOUTHEAST ARIZONA THIS AFTERNOON. RECENT REPORTS OF SNOW FALLING
AROUND THE TOWN OF CATALINA AND ORACLE SUGGESTED THAT THE SNOW LEVEL
WAS AS LOW AS 3500 FEET IN SPOTS WITH THE HEAVIER SHOWERS. ALTHOUGH
GROUND TEMPERATURES ARE TOO WARM FOR ANY SIGNIFICANT ACCUMULATIONS
AT THIS TIME. THAT SAID...CONCERNED ABOUT THE EASTERN CWA AS THE
PRECIPITATION BAND TRACKS FARTHER EAST THIS EVENING. WILL GO AHEAD
AND POST A WINTER WEATHER ADVISORY FOR VALLEY LOCATIONS WHICH 1 TO 2
INCHES MIGHT ACCUMULATE AFTER DARK THIS EVENING AND TONIGHT. WILL
ALSO INCLUDE THE MOUNTAINS WITH THE WEST FACING SLOPES PICKING UP
SEVERAL INCHES LATER THIS EVENING AND TONIGHT. OTHERWISE...WILL
CONTINUE THE WINTER STORM WARNING FOR THE WHITE MOUNTAINS AND THE
WINTER WEATHER ADVISORY FOR THE MOUNTAINS JUST EAST AND NORTHEAST OF
TUCSON. PLEASE REFER THE LATEST WWA PRODUCT UNDER THE AWIPS HEADER
PHXWSWTWC OR WMO HEADER WWUS45. LATEST HRRR SOLUTIONS SHOWED THE
BULK OF PRECIPITATION SHIFTING INTO OUR EASTERN CWA BY 06Z WITH
CLEARING MAINLY WEST OF TUCSON. THEREAFTER...LOOKING AT MORE OR LESS
SCATTERED SHOWERS ON FRIDAY AS AN IMPULSE DROPS SOUTH ON THE
BACKSIDE OF THE MAIN SYSTEM WHICH WAS PROGGED TO MOVE INTO THE TEXAS
PANHANDLE FRIDAY AFTERNOON. ALONG WITH THE WET WEATHER...STRONG AND
GUSTY WINDS CAN BE ANTICIPATED THIS EVENING AS THE SYSTEMS PASSES
THROUGH THE AREA. IMPROVING WEATHER FRIDAY NIGHT AND SATURDAY BEFORE
YET ANOTHER A WEAKER SYSTEM IMPACTS THE STATE AROUND SATURDAY NIGHT
AND SUNDAY.
&&
.AVIATION...VALID THRU 09/00Z.
BKN-OVC CLOUDS 7-10K FT MSL WITH VALLEY RAIN AND MOUNTAIN SNOW.
MOUNTAINS MOSTLY OBSCURED ABOVE 5000 FEET MSL DUE TO CLOUDS AND
PCPN. BRIEF LOCAL IFR CONDITIONS WILL EXIST WITH THIS PRECIPITATION.
CONDITIONS IMPROVING FROM WEST TO EAST AFT 08/06Z. SURFACE WIND
BECOMING SWLY 12-20 KTS WITH GUSTS TO 35 KTS POSSIBLE ESPECIALLY IN
COCHISE COUNTY. WIND EASING AFTER 08/02Z BECOMING SW-W 10 KTS OR
LESS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT PERIODS OF VALLEY RAIN AND MOUNTAIN SNOW INTO
THE EVENING FOR THE MAJORITY OF SOUTHEAST ARIZONA...WITH ANOTHER
PERIOD OF SHOWERS FRIDAY MAINLY ZONES 152 AND 153. DRY CONDITIONS
RETURN ACROSS MUCH OF THE AREA SATURDAY WITH ANOTHER CHANCE OF
SHOWERS SUNDAY. DRY CONDITIONS WITH A VERY MODEST WARMING TREND WILL
THEN PREVAIL MONDAY INTO TUESDAY. BREEZY TO WINDY SOUTHWEST WINDS
WILL OCCUR TODAY...OTHERWISE 20-FOOT WINDS WILL GENERALLY BE TERRAIN
DRIVEN AND MAINLY LESS THAN 15 MPH.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING TIL 11 AM MST FRIDAY FOR AZZ510.
WINTER WEATHER ADVISORY TIL 5 AM MST FRIDAY FOR
AZZ506-509-5011>5014.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
P
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1105 AM MST THU JAN 7 2016
.UPDATE...
ISSUED AT 1104 AM MST THU JAN 7 2016
SNOW BAND AFFECTING THE EASTERN PORTIONS OF THE DENVER METRO AREA
DOWN INTO THE PALMER DIVIDE HAS BEEN QUITE PERSISTENT THIS
MORNING. AT THIS POINT...NOT SURE WE WILL SEE MUCH EROSION OR
MOVEMENT THROUGH THE AFTERNOON AS ITS BEING DRIVEN BY MID LEVEL
CONVERGENCE UNDERNEATH THE UPPER LEVEL COL. THERE MAY ALSO BE
CONVECTIVE REDEVELOPMENT IN THE FOOTHILLS GIVEN SOME BREAKS IN
THE CLOUDS AND A VERY UNSTABLE AIRMASS PER 12Z DENVER SOUNDING.
THOSE SHOWERS MAY BE VERY SLOW MOVING AND PRODUCE SPOTTY HEAVIER
SNOWFALL. SOME INDICATIONS BY HRRR THAT THESE SPREAD SOUTHEAST
INTO THE I-25 CORRIDOR VERY LATE THIS AFTERNOON/EARLY EVENING.
OVERALL...CONFIDENCE THROUGH THE REST OF THE DAY IS LOW BUT
CONFIDENCE IMPROVES THIS EVENING THROUGH FRIDAY MORNING WHEN MORE
WIDESPREAD SNOWFALL IS EXPECTED BEHIND WEAK FRONTAL PUSH AND
UPSLOPE FORCED SNOWFALL. WINTER WEATHER ADVISORIES LOOK PRETTY
GOOD RIGHT NOW WITH TRAVEL IMPACTS EXPECTED BY THIS EVENING AS
SNOW INCREASES AND TEMPERATURES DROP WITH NIGHTFALL.
UPDATE ISSUED AT 739 AM MST THU JAN 7 2016
CURRENT RADAR IMAGERY SHOWS LIGHT SNOW IS TRYING TO FILL IN ALONG
THE FRONT RANGE. IN FACT...SOME LIGHT SNOW HAS ALREADY DEVELOPED
IN PORTIONS OF THE METRO AREA PER LATEST OBSERVATIONS FROM
CENTENNIAL AIRPORT. HRRR SEEMS TO HAVE BEST HANDLE ON THIS FOR
NOW...WEAKENING IT DURING THE DIURNAL MINIMA LATER THIS MORNING
INTO EARLY AFTERNOON...AND THEN INCREASING AGAIN THIS EVENING.
CURRENT FORECAST LOOKS ON TRACK...ONLY MINOR POP CHANGES THIS
MORNING TO REFINE AREAS OF LIGHT SNOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM MST THU JAN 7 2016
RADAR AND WEB CAMERAS INDICATE WIDESPREAD LIGHT SNOW HAS MOVED
OVER WESTERN AND CENTRAL COLORADO. LOOKING AT WATER VAPOR
SATELLITE IMAGERY...IT APPEARS DIFFLUENT FLOW ALOFT IS HELPING TO
PRODUCE THIS SNOW. EXPECT THE SNOW TO SLOWLY SHIFT EAST OVER THE
FRONT RANGE MOUNTAINS THIS MORNING. STILL UNCERTAIN IF SNOW WILL
MAKE ONTO THE URBAN CORRIDOR TODAY. IF IT DOES MAKE IT...SNOWFALL
WILL BE LIGHT AND THE SNOW WILL LIKELY MELT ON THE ROADWAYS DUE TO
TEMPERATURES NEAR THE FREEZING POINT. LOWERED POPS FOR TODAY
ACROSS THE DENVER AREA AND EASTERN PLAIN WHERE SNOW LOOKS LESS
CERTAIN. THE BEST CHANCE FOR SNOW LOOKS TO BE LATE THIS AFTERNOON
WITH THE NEXT WAVE MOVING INTO THE DESERT SOUTHWEST. THIS MAY BE
IN TIME FOR THE EVENING COMMUTE.
BETTER CHANCE FOR SNOW WILL BE TONIGHT WHEN THE SECOND WAVE
CURRENTLY MOVING ONTO THE SOUTHERN CALIFORNIA COAST MOVES OVER THE
FOUR CORNERS. THE ECMWF AND GEM CONTINUE TO LEAD THE WAY AND SHOW
AROUND A QUARTER INCH TO A THIRD INCH OF QPF FOR TONIGHT. THE 00Z
GFS IS STARTING TO CATCH UP TO THEM. EVEN THOUGH CONFIDENCE IS HIGH
THAT WE SEE SNOW...CONFIDENCE IN SNOWFALL AMOUNTS REMAINS LOW. A
SURFACE HIGH BUILDING OVER THE NORTHERN ROCKIES AND A SURFACE LOW
OVER NORTHEAST NEW MEXICO/NORTHWEST TEXAS WILL HELP PRODUCE UPSLOPE
FLOW LATE TONIGHT AND INTO FRIDAY. AIRMASS WILL BE MOIST TONIGHT
AND LAPSE RATES WILL BE 6 TO 8 C/KM. SO ANY LIFT WILL LIKELY
PRODUCE LIGHT SNOW.
WILL ISSUE AN ADVISORY FOR THE MOUNTAINS...FOOTHILLS AND DENVER AREA.
EXPECT 5-10 INCHES FOR THE MOUNTAINS WITH 4-8 SOUTHERN FOOTHILLS AND
3-7 FOR THE NORTHERN FOOTHILLS AND DENVER METRO AREA. MAIN IMPACT
FROM THIS SYSTEM WILL BE SNOWPACKED AND ICY ROADS TONIGHT AND FRIDAY
MORNING EVEN IF SNOWFALL AMOUNTS FALL SHORT OF ADVISORY CRITERIA.
SNOW IS EXPECTED TO BEGIN LATE THIS AFTERNOON OR EARLY EVENING AND
MAY CATCH THE EVENING COMMUTE. THE FRIDAY MORNING COMMUTE WILL
LIKELY BE SLOW AND SLIPPERY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 344 AM MST THU JAN 7 2016
THE FORECAST CONUNDRUM OF THE PAST COUPLE OF DAYS HAS IMPROVED SOME
THIS SHIFT WITH BETTER CONTINUITY IN THE 00Z AND 06Z MODEL RUNS.
MODELS HAVE CONVERGED UPON THE UPPER LEVEL CLOSED LOW OVER THE 4-
CORNERS THURSDAY EVENING TRACKING EAST-SOUTHEASTWARD ACRS NRN NEW
MEXICO DURING THE DAY FRIDAY. THERE`S ALSO BETTER AGREEMENT AS TO
WHEN A RATHER STG COLD FRONT WILL DROP SOUTH INTO NERN COLORADO AND
ARRIVE IN THE DENVER METRO AREA. THE LEADING EDGE OF THIS COLDER
AIRMASS APPEARS TO REACH THE DENVER AREA LATE THURSDAY NIGHT...BUT
THE MAIN PUSH OF COLD AIR ARRIVES WITH SFC-600 MB NELY WINDS OF 10-
20KTS DURING THE 12Z-18Z TIME INTERVAL ON FRIDAY AS THE UPPER LOW
PASSES TO OUR SOUTH. THIS IS ALSO THE PERIOD OF GREATEST QG ASCENT
OVER THE AREA...THOUGH NOTHING EXTRAORDINARY BY ANY MEANS. FORCING
ALOFT COMBINED WITH WEAK LEE SLOPE OROGRAPHICS/UPSLOPE FLOW AND A
MOIST LAPSE RATE TO AROUND 600 MBS SHOULD BE SUFFICIENT TO GENERATE
ANOTHER 1.5-4 INCHES OF SNOW ACROSS SRN PORTIONS OF THE I-25 URBAN
CORRIDOR INCLUDING THE DENVER METRO AREA AND ADJACENT FOOTHILLS...
WITH LESSER AMOUNTS IN AREAS TO THE NORTH AND EAST. RIDGE TOPS AND
EAST SLOPES IN MTN ZONES 33-34 COULD ALSO PICK UP ANOTHER 2-5 INCHES
DURING THE DAY FRIDAY. THE WINTER WEATHER ADVISORY FOR SNOW IS
SET TO EXPIRE AT 21Z/FRIDAY.
AFTER 21Z/FRIDAY...MODELS SHOW THE NELY UPSLOPE FLOW ON THE
PLAINS WEAKENING WITH THE CORE OF COLDEST AIR AND MAX SFC PRESSURE
PASSING TO OUR SOUTHEAST. DEPTH OF THE MOISTURE EAST OF THE FRONT
RANGE ALSO GRADUALLY LOWERS AS DRIER AIR BEGINS TO ENTRAIN
DOWNWARD FROM MID-LEVELS IN NWLY FLOW. AS A RESULT SHOULD SEE A
STEADY DECLINE IN SNOWFALL INITIALLY ALONG THE FRONT RANGE AND
EVENTUALLY OUT ACROSS THE PLAINS BY AROUND MIDNIGHT. IF IT WERE
NOT FOR THE LINGERING CLOUD COVER OVERNIGHT TEMPERATURES WOULD
CERTAINTY PLUNGE BELOW ZERO IN MANY AREAS WITH THE FRESH SNOW
COVER AND LIGHT WINDS. HIGH TEMPERATURES ON FRIDAY AT LEAST 10
DEG F LOWER THAN THOSE TODAY DUE TO HEAVY CLOUD COVER...SNOWFALL
AND ONGOING COLD AIR ADVECTION.
LOOKING AHEAD TO THE WEEKEND...TEMPERATURES WILL STRUGGLE TO WARM
WITH LINGERING CLOUD COVER AND WEAK COLD AIR ADVECTION WITH
NORTHWEST FLOW SFC AND ALOFT. A WEAK WEATHER DISTURBANCE/SHORTWAVE
TROUGH MOVING ALONG MODERATE NWLY FLOW ALOFT IS FORECAST BY A
MAJORITY OF THE MODELS TO CLIP NERN COLORADO DURING THE SATURDAY
AFTERNOON/EVENING TIME FRAME. COULD SEE AN UPTICK IN HIGH COUNTRY
SNOWFALL WITH ITS PASSAGE AS WELL AS A SLIGHT CHANCE OF LIGHT SNOW
ON THE PLAINS...MAINLY ACROSS THE NORTHEAST CORNER OF THE CWA.
ADDITIONAL SNOW AMOUNTS GENERALLY LESS THAN 2 INCHES FOR THE HIGH
COUNTRY AND PRETTY MUCH NOTHING ON THE PLAINS. TEMPERATURE GUIDANCE
NOW IN BETTER AGREEMENT WITH HIGHS IN THE 20S ON THE PLAINS BOTH
DAYS AND TEENS/LOW 20S IN THE MTNS/HIGH VALLEYS. HIGH MTN VALLEY
LOWS WILL TURN QUITE COLD AGAIN BUT NO WHERE AS BITTER COLD AS THEY
WERE SEVERAL DAYS AGO.
NEXT WEEK LOOKS DRY AND WARMER WITH A HIGH RIDGE BUILDING IN FROM
THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 1104 AM MST THU JAN 7 2016
BAND OF PERSISTENT SNOW STILL AFFECTING KDEN TO KAPA CORRIDOR.
MOST OF THIS SNOW SHOULD REMAIN LIGHT...WITH PERHAPS A HALF TO ONE
INCH OF ADDITIONAL ACCUMULATION. EXCEPTION WOULD BE NEAR KAPA
WHERE A SMALL AREA OF HEAVY SNOW COULD DROP ANOTHER 1-2 INCHES
THIS AFTERNOON. SNOW MAY SPREAD BACK OR REDEVELOP TO KBJC AND KFNL
BY 21Z-00Z...AND THEN BECOME WIDESPREAD ALL AREAS 00Z-04Z.
VISIBILITIES WILL RANGE FROM 1 TO 2 MILES FOR MOST OF THE LONG
DURATION SNOW EVENT INTO EARLY FRIDAY AFTERNOON...WITH POTENTIAL
FOR OCCASIONAL VISIBILITIES DOWN TO ONE HALF MILE. CEILINGS WILL
MOSTLY RANGE 500 TO 2000 FEET IN THE SNOW. TOTAL SNOWFALL THROUGH
FRIDAY AFTERNOON IS EXPECTED TO BE 3 TO 6 INCHES...WITH POTENTIAL
FOR SLIGHTLY HIGHER AMOUNTS AT KAPA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 2 PM MST
FRIDAY FOR COZ035-036-039>041.
WINTER WEATHER ADVISORY UNTIL 2 PM MST FRIDAY FOR COZ033-034.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...MEIER
LONG TERM...BAKER
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
231 PM EST THU JAN 7 2016
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE
NORTH THROUGH FRIDAY. A WEAKENING UPPER-LEVEL DISTURBANCE WILL
HELP CAUSE A CHANCE OF SHOWERS LATE TONIGHT INTO FRIDAY. A MORE
SIGNIFICANT FRONTAL SYSTEM WILL MOVE INTO THE REGION SATURDAY AND
SHIFT EAST OF THE AREA LATE SATURDAY NIGHT. IT WILL BE DRY WITH
BREEZY WEST WINDS BEHIND THE FRONT SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE HIGH PRESSURE WILL CONTINUE TO EXTEND INTO THE FORECAST
AREA FROM THE NORTH. MOISTURE AND INSTABILITY ASSOCIATED WITH A
MID-LEVEL SHORTWAVE TROUGH WILL MOVE INTO THE AREA TONIGHT. THE
GREATER LIFT WILL OCCUR LATE. THE HRRR SUGGESTS SCATTERED SHOWERS
WILL BEGIN MOVING INTO THE CSRA FROM THE SOUTHWEST AROUND
MIDNIGHT. THE DAMPENING UPPER SYSTEM WITH WEAK ISENTROPIC LIFT
COMBINED WITH AN AVERAGE OF THE NAM AND GFS MOS PLUS SREF GUIDANCE
SUPPORTS CHANCE POPS. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THE MODELS DISPLAY SURFACE RIDGING EXTENDING INTO THE FORECAST
AREA FROM THE NORTH THROUGH FRIDAY NIGHT. MOISTURE AND INSTABILITY
ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH WILL LINGER INTO
FRIDAY MORNING. THE MODELS SHOW SHALLOW MOISTURE FRIDAY AFTERNOON
AND NIGHT BUT SOME CONTINUED WEAK ISENTROPIC LIFT. HAVE FORECASTED
A DIMINISHED RAIN CHANCE FRIDAY AFTERNOON AND NIGHT. THE
NAM...GFS...AND ECMWF INDICATE MOISTURE BECOMING DEEP SATURDAY
AHEAD OF A WARM FRONT AND APPROACHING COLD FRONT. THE MODELS
DISPLAY THE DEEPEST MOISTURE LATE SATURDAY AFTERNOON AND WE HAVE
PLACED THE HIGHEST POPS DURING THAT TIME. THE NAM AND ECMWF
INDICATED RAIN AMOUNTS AROUND 0.25 OF AN INCH. THE SREF MEAN WAS
NEAR 0.50 AND GFS LESS THAN 0.25 OF AN INCH. WE USED AN AVERAGE
OF THE GUIDANCE. THE NAM AND GFS INDICATE HIGH SHEAR WITH AN H85
JET OF 35 TO 50 KNOTS. THE NAM HAD THE GREATER SHEAR. DESPITE THE
STRONG SHEAR THE SEVERE THREAT SHOULD REMAIN LOW BECAUSE OF A LACK
OF SURFACE-BASED INSTABILITY. THE NAM DISPLAYED SURFACE-BASED LI/S
RANGING FROM 4 IN THE WEST TO NEAR 0 IN THE EAST LATE SATURDAY
AFTERNOON INTO THE EVENING. THE NAM AND GFS HAD CROSS TOTALS IN
THE MIDDLE 20S AND A FEW ELEVATED THUNDERSTORMS MAY OCCUR. EXPECT
DRYING BEHIND THE COLD FRONT LATE SATURDAY NIGHT. USED THE LOWER
HIGH TEMPERATURE GUIDANCE FRIDAY AND SATURDAY BECAUSE OF A WEDGE
PATTERN. THE LOW TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE GFS AND ECMWF INDICATE A DRY PATTERN DURING THE MEDIUM-RANGE
PERIOD. THE MODELS DEPICT LITTLE MOISTURE ASSOCIATED WITH A
REINFORCING COLD FRONT WEDNESDAY. BREEZY CONDITIONS WILL LIKELY
OCCUR BEHIND THE COLD FRONT SUNDAY. IT MAY BE BREEZY AGAIN
WEDNESDAY BECAUSE OF THE REINFORCING COLD FRONT. THE
GFS...ECMWF...AND EKD MOS HAVE POPS LESS THAN OR EQUAL TO 20
PERCENT THOUGH THE PERIOD. THE MOS HAS ABOVE NORMAL TEMPERATURES
SUNDAY BUT WIND SHOULD MAKE IT FEEL COOLER. THE MOS HAS NEAR OR
BELOW NORMAL TEMPERATURES DURING THE REST OF THE PERIOD.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
BAND OF EARLIER LOW CLOUDINESS HAS LIFTED...WITH VFR CONDITIONS
EXPECTED TO CONTINUE AT OUR TERMINALS THIS AFTERNOON INTO THE EARLY
EVENING. A NE LOW LEVEL FLOW IS EXPECTED TO CONTINUE THROUGH THE TAF
PERIOD WITH WEAK SURFACE HIGH PRESSURE RIDGING DOWN THE EASTERN
SEABOARD AND SURFACE LOW WELL OFFSHORE. THIS MAY PROVIDE
FOR LOWER CLOUDINESS...AND POSSIBLY FOG...TO REDEVELOP AGAIN
TONIGHT TO OUR NE EARLY TONIGHT AND SHIFT SW INTO OUR FORECAST
AREA...PER LATEST HIGH RESOLUTION MODELS. BASED ON
CONTINUITY...AND ON RELATIVE CONSISTENCY IN MODEL GUIDANCE...THINK
CONFIDENCE OF IFR CIGS TONIGHT AND FRIDAY MORNING IS HIGH...BUT
CONFIDENCE ON THE EXTENT OF RESTRICTIONS TO VSBYS LIMITED. AT THIS
TIME...WILL INDICATE CONDITIONS DETERIORATING TO IFR
TONIGHT...HITTING THE CIGS HARDER THAN THE VSBYS FOR NOW. WEAK
UPPER DISTURBANCE APPROACHING FROM THE WEST AND RESULTANT WEAK
ISENTROPIC LIFT EXPECTED TO PROVIDE CHANCE OF LIGHT RAIN LATE
TONIGHT AND FRIDAY MORNING. THE LIGHT RAIN ACTIVITY MAY DICTATE
ONLY SLOW IMPROVEMENT...IF ANY...IN FLIGHT CATEGORIES FRIDAY
MORNING.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE FRIDAY
AFTERNOON. MVFR TO IFR RESTRICTIONS EXPECTED FRIDAY
NIGHT...SATURDAY AND SATURDAY NIGHT....WITH CHANCE OF RAIN SAT/SAT
NT. NO RESTRICTIONS EXPECTED SUNDAY/MONDAY...THOUGH BREEZY
CONDITIONS POSSIBLE SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1224 PM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 1205 AM CST THU JAN 7 2016
EARLIER THIS MORNING...EXTENDED THE FOG HEADLINE. ALTHOUGH
VISIBILITIES...HAVE IMPROVED IN SOME LOCATIONS WITH THE RAIN
MOVING IN FROM THE SOUTH AND FOR PARTS OF NORTHEAST NEBRASKA.
WILL CONTINUE TO MENTION DENSE FOG NORTH OF THE RAIN AREA THIS
AFTERNOON.
WITH THE MORNING MODEL RUNS...THE NAM IS TOO COLD WITH THE SURFACE
TEMPERATURES AND THIS WILL BE CRITICAL FOR PRECIP TYPE. THE
NAM/GFS KEEP THE HIGHER PRECIP WHERE IT REMAINS LIQUID THIS
AFTERNOON. THE RUC IS A BIT FARTHER NORTH INTO THE COLDER AIR.
RAISED SOME OF THE QPF AMOUNTS WITH THE RAIN BAND. WILL CONTINUE
TO MONITOR SHORT TERM TRENDS AS THE SHORTWAVE MOVES INTO THE AREA
AND THE PRECIPITATION TYPE BECOMES A MIX OR ALL SNOW ON THE
WESTERN/COOLER SIDE OF THE SYSTEM. THE HRRR EXP TRIES TO HAVE A
MIX/SNOW AS EARLY AS THIS AFTERNOON JUST WEST OF THE METRO AREA.
FORECAST SOUNDINGS ARE ISOTHERMAL AND THERE MAY BE PERIODS OF
PRECIP TYPE SWITCHING BACK AND FORTH UNTIL THE AIRMASS IS
SUFFICIENTLY COOL...AS THE SURFACE LOW TRACKS INTO EASTERN KANSAS
AND WESTERN IOWA.
UPDATE ISSUED AT 525 AM CST THU JAN 7 2016
DENSE FOG HAD BECOME A BIT MORE WIDESPREAD THE PAST FEW HOURS...SO
DECIDED TO ISSUE A DENSE FOG ADVISORY UNTIL 9 AM CST FOR A LARGE
PART OF THE FORECAST AREA. NO OTHER CHANGES TO PREVIOUS FORECAST.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
THE MAIN FORECAST ISSUES REVOLVE AROUND PCPN TYPE AND PCPN AMOUNTS...
INCLUDING SOME LIGHT SNOW ACCUMULATIONS.
UPPER AIR CHARTS FROM 00Z SHOWED THE FOLLOWING MAIN FEATURES. AT
300 MB...STRONGEST WINDS (UP TO ABOUT 130 KNOTS) WERE MOVING
EASTWARD FROM THE PACIFIC ACROSS NORTHERN MEXICO. A BLOCKING
RIDGE AT 500 MB WAS CENTERED ALONG THE BORDER OF THE YUKON AND
NORTHWEST TERRITORIES...WHILE A TROUGH STRETCHED FROM THE GULF OF
ALASKA DOWN TO OFF THE CALIFORNIA COAST. AT 700 MB...THERE WAS A
LACK OF A BAROCLINIC ZONE ACROSS THE CENTRAL PLAINS. THE COLDEST
AIR AT THIS LEVEL WAS ALONG THE WEST COAST. THERE WAS MORE OF A
THERMAL CONTRAST NOTED AT 850 MB ACROSS THE NORTHERN AND CENTRAL
PLAINS...WITH -8 C AT KBIS...RANGING TO +2C AT KTOP. THE KOAX
SOUNDING SHOWED ABOUT 0.51 INCHES OF PW...AND IT WAS NEARLY
SATURATED UP TO 6000 FEET AGL. SFC ANALYSIS EARLY THIS MORNING
SHOWED LOW PRESSURE CENTERS OVER COLORADO AND EASTERN SOUTH
DAKOTA. SOUTHEAST SURFACE WINDS WERE IN PLACE OVER EASTERN
NEBRASKA AND SOUTHWEST IOWA...WITH TEMPERATURES IN THE LOWER AND
MID 30S.
A SHORTWAVE HAD MOVED ACROSS THE CENTRAL PLAINS YESTERDAY...AND WAS
MOVING TOWARD THE WESTERN GREAT LAKES REGION. THE NEXT SHORTWAVE OF
CONCERN WAS DEPICTED FAIRLY WELL WITH A COMBINATION OF RECENT WATER
VAPOR SATELLITE IMAGERY AND RUC MODEL INITIALIZATIONS...NEAR THE
BORDER OF NEW MEXICO...TEXAS AND OKLAHOMA. THAT FEATURE SHOULD MOVE
TOWARD CENTRAL KANSAS BY LATE AFTERNOON AND HELP BRING INCREASING
MOISTURE (DEEPER) AND LIFT TO THE LOCAL AREA. AREAS OF DRIZZLE...
FOG AND LIGHT RAIN SHOULD PERSIST THIS MORNING...WITH LIGHT RAIN
BECOMING MORE WIDESPREAD IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA
THIS AFTERNOON. THERE WILL BE A CHANCE OF A MIX OF SNOW...SLEET
AND RAIN IN MUCH OF NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
THE SHORTWAVE TROUGH THAT IS EXPECTED TO BE OVER KANSAS BY LATE
AFTERNOON WILL TRACK NORTHEAST INTO SOUTHERN IOWA FRIDAY AND WEAKEN.
THEN A MORE COMPLEX LIFT PATTERN WILL OCCUR AS ANOTHER DISTURBANCE
LIFTS EAST/NORTHEAST ACROSS KANSAS FRIDAY NIGHT INTO SATURDAY
MORNING AND A COLD TROUGH STARTS DIGGING INTO THE NORTHERN PLAINS.
MIXED PCPN SHOULD CHANGE TO MOSTLY SNOW IN NORTHEAST NEBRASKA AS
WINDS SHIFT TO THE NORTH TONIGHT AND A FEW INCHES OF SNOW MAY
ACCUMULATE. COLDER AIR WILL SPREAD OVER THE REST OF THE AREA FOR
LATE TONIGHT AND THROUGH FRIDAY...WHICH WILL CHANGE THE PCPN TO
MAINLY SNOW FROM NORTHWEST TO SOUTHEAST BY FRIDAY NIGHT. THE SNOW
SHOULD END SATURDAY...AS COLD HIGH PRESSURE STARTS TO BUILD INTO
THE AREA. BY 00Z SUNDAY...HIGH PRESSURE WITH A CENTER OF ABOUT
1031 MB SHOULD BE OVER NORTH DAKOTA.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 315 AM CST THU JAN 7 2016
COLD AIR SHOULD DOMINATE THE FIRST PART OF THIS PERIOD...AS A COLD
NORTH/NORTHWEST FLOW ALOFT BRINGS CANADIAN AIR DOWN INTO OUR AREA.
TEMPERATURES ARE EXPECTED TO MODERATE A BIT BY WEDNESDAY AND
THURSDAY...AS THE FLOW TURNS MORE TOWARD THE WEST. AT THIS TIME...
NO SIGNIFICANT PCPN IS EXPECTED. LIGHT SNOW IS POSSIBLE MONDAY
OVER THE DAKOTAS AND MINNESOTA. AT THIS TIME...EXPECT THAT TO STAY
TO THE NORTH OF OUR AREA.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1205 PM CST THU JAN 7 2016
MVFR/LIFR/VLIFR CONDITIONS EXPECTED THROUGHOUT THE PERIOD.
VISIBILITIES RANGING FROM 1/4 TO 3/4 MILE AT KOMA AND KLNK...AND
1 TO 3 MILES KOFK. AS THE RAIN MOVES NORTH SHOULD SEE LOW VSBYS
IMPROVING...WILL ALSO TRANSITION TO SNOW AT KOFK...A RAIN/SNOW AND
SNOW MIX AT OMAHA AND LINCOLN WITH ON AND OFF/SPOTTY PRECIP
00Z THROUGH 12Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...ZAPOTOCNY
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
103 PM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 102 PM CST THU JAN 7 2016
REMOVED WINTER STORM WARNING AND REPLACED IT WITH A WINTER WEATHER
ADVISORY OVER PARTS OF SOUTHEAST ND AND INTO MN. WINTER WEATHER
ADVISORY NOW COVERS MUCH OF NORTHWEST AND WEST CENTRAL MN. LOOKING
FOR TWO TO FOUR INCHES OF SNOW ROUGHLY FROM GEORGETOWN TO WASKISH
MN. ELSEWHERE LEES SNOW AND SOME FREEZING DRIZZLE WILL BE POSSIBLE
THIS AFTERNOON.
UPDATE ISSUED AT 1004 AM CST THU JAN 7 2016
WATER VAPOR LOOP INDICATED A WEAK UPPER TROUGH OVER CENTRAL ND AND
WAS MOVING EAST. 3 G/KG MIXING RATIOS WERE OVER THE SOUTHEAST ZONES
AND PRECIPITABLE WATER WAS AROUND HALF AN INCH OVER THE
SOUTH/SOUTHEAST ZONES. SURFACE LOW WAS SOUTHEAST OF ABR AND IS
FORECAST TO MOVE NORTHEAST TODAY. RADAR CONTINUES TO SHOW PRECIP
ACCUMULATING OVER SOUTHERN ZONES. WILL KEEP CURRENT ADVISORIES AND
WARNINGS GOING.
UPDATE ISSUED AT 639 AM CST THU JAN 7 2016
SNOW BAND CONTINUES TO EXPAND NORTHEASTWARD...WITH MORE RETURNS
DEVELOPING BACK TO THE SOUTHEAST. SHORT RANGE MODELS CONTINUE TO
KEEP SOME DECENT QPF OVER THE CWA THROUGH THE REST OF THE MORNING.
AND THERE WILL BE FREEZING DRIZZLE LINGERING A BIT LONGER IN SOME
AREAS. WILL EXTEND THE HEADLINES UNTIL 18Z. MAY NEED TO GO LONGER
IF THE HRRR VERIFIES BUT FOR NOW JUST KEEP IT GOING THROUGH THE
NEXT SIX HOURS AND SEE HOW THINGS DEVELOP. ALSO EXPANDED THE
WARNING UP INTO MAHNOMEN...EASTERN POLK...AND NORTHERN CLEARWATER
COUNTIES AS THE BAND MOVES NORTHEAST AND PULLED TRAILL BACK DOWN
TO ADVISORY AS IT SEEMS THE HEAVIEST AMOUNTS HAVE MISSED THEM.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
WHAT HAPPENS WITH THE MESOSCALE SNOW BAND AND WHAT TO DO WITH
HEADLINES WILL BE THE MAIN FORECAST HEADACHE FOR THE SHORT TERM.
WEAK SHORTWAVE TROUGH MOVING THROUGH ND...WITH A SFC LOW OVER
NORTH CENTRAL SD. THE MESOSCALE SNOW BAND OVER THE SOUTHERN RED
RIVER VALLEY HAS CONTINUED TO SLOWLY MOVE SOUTHEAST. THE
MID LEVEL FRONTOGENESIS DOES NOT LOOK ALL THAT STRONG WHERE THE
BAND IS LOCATED...BUT WITH NEGATIVE EPV AND HIGH MID LEVEL LAPSE
RATES THERE HAS BEEN ENOUGH INSTABILITY TO GET A NARROW AREA OF
HEAVY SNOW. WHERE THE BEST FRONTOGENSIS IS LOCATED OVER THE
NORTHWESTERN CWA A BAND TRIED TO GET GOING...BUT SEEMS TO BE
DISSIPATING LAST FEW SCANS. THERE HAS BEEN A REPORT OF 6 PLUS
INCHES IN CASSELTON SO THE WARNING SEEMS TO BE ON TRACK. THE HOP
WRF...RAP...AND HRRR ALL HAVE A NARROW BAND OF HIGH SNOW
ACCUMULATION EXTENDING FROM CENTRAL CASS COUNTY UP INTO THE
CLAY/NORMAN AREA. THERE ARE HINTS THAT THE HEAVY SNOW COULD EXTEND
FURTHER NORTHEAST...AND THERE HAS BEEN SOME FAIRLY HEAVY RADAR
RETURNS IN NORTHEASTERN MAHNOMEN COUNTY CURRENTLY. GIVEN THAT THE
EPV AND LAPSE RATES SLOWLY BECOME A BIT LESS FAVORABLE GOING INTO
TODAY...AM NOT SURE HOW LONG THE BAND WILL BE PRODUCING 2 PLUS PER
HOUR SNOWFALL RATES. HAVE THE HEAVY SNOW BAND IN THE GRIDS
EXTENDING INTO THE FAR CORNER OF MAHNOMEN...BUT WILL KEEP THE
HEADLINES AS THEY ARE FOR NOW AND REEVALUATE WHEN WE GET A BIT
MORE GROUND TRUTH LATER THIS MORNING.
THE OTHER ISSUE WILL BE FREEZING DRIZZLE. THE PKD ASOS CONTINUES
TO REPORT AN I GROUP AT TIMES...AND MODEL SOUNDING ACROSS MUCH OF
THE CWA SHOW A DRY LAYER ALOFT EXCEPT WHEN THE SNOW BAND IS
GOING THROUGH. WILL CONTINUE TO KEEP A FREEZING DRIZZLE MENTION
THROUGH THE REST OF THE MORNING AND WILL KEEP THE ADVISORY GOING
IN THE SOUTH FOR THAT REASON. THERE ARE SOME SIGNS OF DRIER AIR
ALOFT COMING IN TONIGHT...PARTICULARLY IN THE WESTERN COUNTIES AS
COLDER AIR COMES DOWN THE BACKSIDE OF THE SFC LOW. WILL INCLUDE A
SLIGHT CHANCE OF FREEZING DRIZZLE MENTION FOR TONIGHT...FOLLOWING
WHERE THE MODELS HAVE THE LOWER CHANCES OF ICE CRYSTALS IN THE
CLOUD.
LIGHT SNOW WILL ALSO CONTINUE AT TIMES AS THE MAIN UPPER
TROUGH DIGS DOWN OUT OF CANADA ON FRIDAY. DO NOT THINK THERE WILL
BE VERY MUCH ACCUMULATION...BUT KEPT SOME CHANCE POPS FOR UP TO
HALF AN INCH OF ACCUMULATION. THE ARCTIC AIR WILL START BUILDING
DOWN INTO THE NORTHERN PLAINS FRIDAY. MODELS HAVE 925MB
TEMPERATURES DOWN TO -20 C BY LATE AFTERNOON. THINK THAT READINGS
WILL FALL THROUGHOUT THE DAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 349 AM CST THU JAN 7 2016
FRIDAY NIGHT THROUGH SATURDAY NIGHT...ARCTIC HIGH PRESSURE PARKS
ITSELF OVER THE NORTHERN PLAINS. THINK THAT THERE MAY BE A BIT OF
LIGHT SNOW LINGERING OVER THE NORTHEAST INTO FRIDAY NIGHT...BUT
OTHERWISE THERE WILL BE CLEARING OUT AND COLD THROUGH THE PERIOD.
TEMPS WILL BE BELOW ZERO EVEN INTO SATURDAY AFTERNOON...AND COULD
DROP DOWN TO THE 15 TO 20 BELOW RANGE SATURDAY NIGHT. WIND CHILLS
WILL ALSO MAKE IT SEEM EVEN COLDER.
SUNDAY-WEDNESDAY...BELOW AVE TEMPS WILL CONTINUE TO BE THE THEME
DURING THIS TIME. ANOTHER COLD DAY IS EXPECTED FOR SUNDAY...EVEN AS
THE COLDEST 850 MB TEMPS SHIFT EAST AND THE SFC HIGH DROPS SOUTH OF
REGION. THE NEXT ARCTIC FRONT LOOKS TO SWEEP THROUGH AROUND
MONDAY...REINFORCING THE COLD AIR THROUGH THE EARLY PART OF THE
WEEK. CURRENTLY HAVE THE EARLY WEEK PERIOD DRY...BUT THE 00Z
GFS/ECMWF DO SHOW A CLIPPER SYSTEM MOVING SOUTH WITH THE ARCTIC AIR
MONDAY...WITH SOME POTENTIAL FOR LIGHT SNOW. SOME MODERATION IN
TEMPS IS POSSIBLE BY MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 102 PM CST THU JAN 7 2016
STILL DEALING WITH MAJORITY IFR CONDITIONS ACROSS THE AREA INTO
FRIDAY MORNING. THE PUSH OF COLDER BUT EVENTUALLY DRIER AIRMASS
FROM THE NORTH WILL KICK THE LOW LEVEL MOISTURE OUT BUT PROBABLY NOT
TIL LATE FRIDAY/FRIDAY NIGHT. UNTIL THEN WILL MAINTAIN MOSTLY IFR
AND LOW END MVFR CIGS. VARIABLE VISIBILITY WITH CONTINUED FOG
PATCHES AND LIGHT SNOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
MNZ001>003-009-013>017-022>024-027>032-040.
&&
$$
UPDATE...HOPPES
SHORT TERM...JR
LONG TERM...JR/MAKOWSKI
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1233 PM CST THU JAN 7 2016
.UPDATE...
ISSUED AT 1216 PM CST THU JAN 7 2016
LATEST BATCH OF OBSERVATIONS CONTINUE TO SHOW A SCATTERING OF FOG
WITH A FEW REPORTS OF FREEZING DRIZZLE. THEREFORE WILL PUT PATCHY
FOG/FREEZING DRIZZLE ACROSS THE AREA THROUGH TONIGHT DISSIPATING
FROM NORTHWEST TO SOUTHEAST FRIDAY MORNING AS THE COLD AIRMASS
SHIFTS IN. OTHERWISE...ONLY OTHER CONCERN WAS THE SMALL AREA OF
SNOW MOVING THROUGH NORTHERN PORTIONS OF NORTH DAKOTA SO HAVE
ADJUSTED POPS ACCORDINGLY.
UPDATE ISSUED AT 904 AM CST THU JAN 7 2016
MAIN AREA OF SNOW THAT WAS AFFECTING DICKEY AND LAMOURE COUNTIES HAS
PUSHED TO THE EAST WITH ONLY SOME LIGHT SNOW REMAINING.
THEREFORE...HAVE LET ADVISORY EXPIRE. TO THE NORTH...A WEAK WAVE
MOVING THROUGH IS PRODUCING SOME VERY LIGHT SNOW SO HAVE ADDED
SOME LOW POPS ALONG THE CANADIAN BORDER. OTHERWISE...PREVIOUS
FORECAST WAS IN GOOD SHAPE AND HAD THE FOG AND FREEZING DRIZZLE
ADDRESSED WELL.
UPDATE ISSUED AT 641 AM CST THU JAN 7 2016
EXPANDED THE MENTION OF LIGHT FREEZING DRIZZLE TO ALL OF SOUTH
CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY THIS
MORNING...THROUGH TONIGHT BASED UPON THE NDDOT TRAVEL MAP AS OF 12
UTC...AND 11 UTC RAP SOUNDINGS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CST THU JAN 7 2016
THE MAIN FOCUS FOR TODAY AND TONIGHT IS FREEZING PRECIPITATION.
AN UPPER LEVEL SHORTWAVE CENTERED OVER NORTH DAKOTA...AN INVERTED
SURFACE TROUGH NOSING INTO THE EASTERN DAKOTAS AND MOIST UPSLOPE
FLOW WERE PROVIDING AMPLE LIFT FOR PRECIPITATION DEVELOPMENT THIS
MORNING.
AREAS OF LIGHT SNOW AND FREEZING DRIZZLE CONTINUE TO DEVELOP
ACROSS THE SOUTHERN JAMES VALLEY. PRECIPITATION WILL LIKELY
CONTINUE THERE FOR THE NEXT SEVERAL HOURS AND CLEAR OUT BY THE
LATE MORNING HOURS AS THE WAVE SHIFTS EAST. ONLY MINOR
ACCUMULATIONS OF SNOW ARE EXPECTED (GENERALLY LESS THAN ONE HALF
INCH)...HOWEVER...SOUNDINGS FAVOR A FREEZING DRIZZLE MODE FOR AN
EXTENDED PERIOD OF TIME. THIS MAY LEAD TO A THIN GLAZE OF ICE.
AFTER THE WAVE PUSHES EAST THIS MORNING...ANOTHER WAVE IS EXPECTED
TO ENTER THE AREA TONIGHT. WITH PLENTY OF LOW LEVEL MOISTURE
REMAINING THIS WILL PROVIDE THE LIFT NECESSARY TO REDEVELOP
PRECIPITATION. FREEZING DRIZZLE IS FAVORED ACROSS SOUTH CENTRAL
NORTH DAKOTA AS SLIGHTLY WARMER TEMPERATURES ALOFT ARE FORECAST TO
LEAD TO AN UNSATURATED DENDRITIC GROWTH ZONE. FURTHER WEST AND
NORTH COOLER AIR SHOULD KEEP PRECIPITATION IN THE FORM OF ALL
SNOW. ONLY MINOR ACCUMULATIONS ARE EXPECTED...GENERALLY AN INCH
OR LESS ACROSS PORTIONS OF NORTHERN AND WESTERN NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 321 AM CST THU JAN 7 2016
TWO ARCTIC AIRMASSES AND DANGEROUS WIND CHILLS HIGHLIGHT THE
EXTENDED FORECAST.
PRIOR TO THE ARRIVAL OF THE FIRST ARCTIC AIRMASS...THE 00 AND
INCOMING 06 UTC NAM AND GFS BUFR SOUNDINGS SUPPORT THE POTENTIAL
FOR FREEZING DRIZZLE ACROSS MUCH OF CENTRAL NORTH DAKOTA FRIDAY
MORNING WITH LOW LEVEL SATURATION WARMER THAN -10 C AND A LACK OF
ICE CRYSTALS IN THE COLUMN.
THEREAFTER...THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES
CONTINUE TO SHOW GOOD AGREEMENT ON TWO POSSIBLE ARCTIC AIRMASSES
TO IMPACT WESTERN AND CENTRAL NORTH DAKOTA. THE FIRST...ARRIVING
THROUGH THE DAY ON FRIDAY AND REMAINING IN PLACE THROUGH THE
WEEKEND...WITH A POSSIBLE SECOND SURGE OF ARCTIC AIR MONDAY INTO
TUESDAY. WIDESPREAD DANGEROUS WIND CHILLS AS LOW AS 35 BELOW ARE
FORECAST DURING THE MORNING AND NIGHTTIME HOURS OF SATURDAY AND
SUNDAY. A WIND CHILL ADVISORY WILL LIKELY BE NEEDED THIS WEEKEND.
OVERALL...THE WIND FIELD WITH THE POSSIBLE SECOND SURGE OF ARCTIC
AIR IS STRONGER WHEN COMPARED TO THE FIRST...WHICH MAY INTRODUCE A
BLOWING SNOW THREAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1216 PM CST THU JAN 7 2016
IFR AND LIFR IN STRATUS AND FOG WILL PREVAIL TODAY INTO THIS
EVENING OVER MOST LOCATIONS. CIGS AND VIS MAY IMPROVE TO MVFR ON
FRIDAY AS A COLD AIRMASS SHIFTS INTO THE AREA AND THE FOG AND
FREEZING DRIZZLE DISSIPATE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...AJ
LONG TERM...AYD
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
1008 AM PST THU JAN 7 2016
.SYNOPSIS...AFTER A FEW RESIDUAL SHOWERS ACROSS THE NORTH PART OF OUR
FORECAST AREA TODAY FROM A WEAK DISTURBANCE THAT MOVED NORTH
OVERNIGHT...A LOW OFF THE OREGON AND NORTHERN CALIFORNIA COAST WILL
SEND ONE MORE BAND OF SHOWERS INTO SOUTHWEST OREGON AND NORTHERN
CALIFORNIA THAT WILL BRUSH PARTS OF OUR FORECAST AREAS FROM ABOUT
SALEM SOUTHWARD TONIGHT AND EARLY FRIDAY. DECREASING OFFSHORE FLOW
WILL RESULT IN INCREASING AREAS OF NIGHT AND MORNING FOG AND LOW
CLOUDS TONIGHT AND FRIDAY. THE NEXT SYSTEM IS FORECAST TO APPROACH
FRIDAY NIGHT...WITH SOME MOISTURE LIFTING NORTH INTO NORTHWEST
OREGON AND SOUTHWEST WASHINGTON LATE FRIDAY NIGHT AND ESPECIALLY ON
SATURDAY. THE SYSTEM WILL STRETCH AND WEAKEN AS IT MOVES NORTH...
THEN OUT OF THE AREA BY EARLY SUNDAY. LOOK FOR WINTER PRECIPITATION
IN THE GORGE...AND POSSIBLY IN AREAS WEST OF THE GORGE NEAR THE
COLUMBIA RIVER. THE NEXT SYSTEM IS EXPECTED EARLY NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SATURDAY...A LOW REMAINS OFF THE OREGON
AND NORTHERN CALIFORNIA COAST THIS MORNING. A WEAK SHORT WAVE THAT
LIFTED NORTH THROUGH NORTHWEST OREGON AND SOUTHWEST WASHINGTON
OVERNIGHT STILL HAD A FEW SHOWERS AROUND THIS MORNING FROM ABOUT
PORTLAND NORTH...WHICH WILL LINGER INTO THIS EVENING BUT BECOME MORE
CONFINED TO THE HIGHER TERRAIN.
THERE IS ONE MORE DECENT SHORT WAVE WITH THE OFFSHORE LOW THAT HAS A
DECENT COMMA CLOUD WITH IT THAT WILL MOVE ONTO THE SOUTHERN OREGON
AND NORTHERN CALIFORNIA COASTS THROUGH THE DAY TODAY. SOME OF THIS
MOISTURE WILL ROTATE NORTHWARD INTO OUR SOUTHERN FORECAST ZONES
TONIGHT AND EARLY FRIDAY...PERHAPS AS FAR NORTH AS SALEM...PRODUCING
A FEW SHOWERS. THE BAND IS RATHER CONVECTIVE LOOKING AND WILL USE
THE SHOWER WORDING. OTHERWISE SURFACE PRESSURE GRADIENTS THROUGH THE
GORGE ARE LESS THAN 2 MB NOW AND WILL STAY WEAK INTO FRIDAY
MORNING...SO LOOK FOR MORE AREAS OF NIGHT AND MORNING FOG ESPECIALLY
IN THE VALLEYS TONIGHT AND FRIDAY. THE FOG AND LOW CLOUDS FRIDAY MAY
TAKE A WHILE TO BREAK OUT DUE TO THE LIGHT LOW LEVEL FLOW DOWN THE
VALLEY.
THE NEXT SYSTEM CONTINUES TO BE FORECAST TO APPROACH FRIDAY NIGHT...
TAKE ON A NEGATIVE TILT AS IT MOVES ONSHORE LATER FRIDAY NIGHT AND
SATURDAY. THE MODELS STILL ARE NOT EXACTLY ON THE SAME PAGE...BUT
TRENDS SUGGEST THAT THIS SYSTEM WILL STRETCH AND WEAKEN SOME AS IT
MOVES NORTH SATURDAY...WITH THE ECMWF MODEL THE SLOWEST IN THE
WEAKENING AND STRETCHING. NEVERTHELESS...SOME PRECIPITATION SHOULD
AFFECT PRETTY MUCH ALL OF OUR FORECAST AREA SATURDAY.
WITH DEWPOINTS CURRENTLY RISING INTO THE 30S...THE SLOW MODERATION
THAT IS OCCURRING...AND THAT THE EAST WIND THAT REDEVELOPS LATE
FRIDAY AND FRIDAY NIGHT IS LESS THAN WHAT WE HAD A WEEK AGO...AM
GETTING LESS BULLISH ON THE EXTENT OF WINTER WEATHER FOR THE VALLEYS
ON SATURDAY. THE MODELS TEND TO KEEP AREAS SOUTH OF PORTLAND ALL
RAIN...AND ANY FREEZING RAIN EARLY SATURDAY IN THOSE AREAS LOOKS
ISOLATED AND BRIEF. THE PARKDALE AND HOOD RIVER AREAS AROUND THE
CENTRAL GORGE LOOK TO BE ALL SNOW...WITH A MIXTURE OF SNOW OR
FREEZING RAIN IN THE WESTERN GORGE. IN PORTLAND AND VANCOUVER AREA
IT LOOKS LIKE THERE IS A CHANCE OF RAIN OR SNOW OR FREEZING RAIN...
WITH THE BEST CHANCE NEAR THE GORGE...BUT CANNOT RULE OUT THE COLDER
OUTLYING AREAS OF CLARK COUNTY AND OUT IN THE TUALATIN VALLEY FOR
AWHILE SATURDAY. ALSO BELIEVE THE COLDER SHELTERED VALLEYS OF THE
NORTH OREGON COAST RANGE ARE ALSO AT RISK...AND PERHAPS UP TOWARD
KELSO AS WELL. HAVE MADE SOME OF THESE ADJUSTMENTS IN THE MORNING
FORECAST PACKAGE...BUT WILL NEED TO FINE TUNE THIS SOME MORE IN THE
AFTERNOON PACKAGE. THIS EVENT DOES NOT LOOK TO HAVE THE WIDESPREAD
IMPACTS OF LAST SUNDAY... THOUGH IT MAY GET A LITTLE DICEY AROUND
THE COLUMBIA RIVER FOR A WHILE. TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SATURDAY NIGHT
THROUGH WEDNESDAY...IT APPEARS THE SATURDAY SYSTEM SHOULD MOVE AWAY
SUNDAY FOR DRYING. AFTER A BRIEF UPPER RIDGE...THE NEXT SYSTEM IS
EXPECTED EARLY NEXT WEEK. THE FASTER GFS MAY BE A BIT TOO FAST...AND
CURRENTLY BLENDED TOWARD THE SLOWER ECMWF. HAVE ADDED A SLIGHT CHANCE
OF FREEZING RAIN TO MUCH OF THE AREA AWAY FROM THE COAST MONDAY
MORNING BUT THIS MAY CHANGE AS THE MODELS SHIFT OVER THE COMING DAYS.
BOWEN/TOLLESON
&&
.AVIATION...PRIMARILY VFR THIS MORNING...EXCEPT FOR AREAS OF IFR/LIFR
IN THE CENTRAL AND SOUTH INTERIOR VALLEYS. DO NOT SEE MUCH CHANGE IN
OVERALL CONDITIONS THROUGH THE MORNING. SPOTTY LIGHT PRECIP MAY
RESULT IN BRIEF PERIODS OF VIS/CIG RESTRICTIONS ANYWHERE AWAY FROM
THE COLUMBIA GORGE. EXPECT VFR TO PREVAIL DURING THE AFTERNOON AND
EVENING HOURS. HOWEVER...CONTINUED EAST LOW-LEVEL FLOW THROUGH THE
GORGE WILL MAINTAIN STRATUS IN THE COLUMBIA BASIN RESULTING IN
MOUNTAIN OBSCURATION ALONG THE CASCADES AND PERSISTENT IFR IN THE
HOOD RIVER VALLEY. EXPECT AREAS OF IFR/LIFR TO RETURN TO THE CENTRAL
AND SOUTH INTERIOR VALLEYS OVERNIGHT AND INTO FRI MORNING.
KPDX AND APPROACHES...VFR TO CONTINUE THROUGH FRI MORNING.
HOWEVER...LOCAL MVFR THROUGH THE MORNING ALONG WRN APPROACHES.
OFFSHORE LOW-LEVEL GRADIENT HAS WEAKENED TO -2.0 MB AS OF 16Z. THE
GRADIENT STRENGTHENS A LITTLE TONIGHT AND FRI MORNING. DO NOT EXPECT
EAST WIND AT THE TERMINAL TODAY...BUT MAY SEE 5-10 KT OVERNIGHT INTO
FRI MORNING. WEISHAAR
&&
.MARINE...WEAK SURFACE LOW OFF THE S OREGON COAST NEAR 125W WILL
CONTINUE TO DISSIPATE AND MOVE NE TODAY. WIND SPEEDS TO REMAIN BELOW
SMALL CRAFT ADVISORY THRESHOLDS...BUT THE HRRR AND NAM INDICATE
POSSIBLE 20-25 KT GUSTS OVER THE FAR SW CORNER OF PZZ275 TODAY.
PRESSURE GRADIENTS ARE EXPECTED TO TIGHTEN A BIT TONIGHT AND FRI AS
HIGH PRESSURE STRENGTHENS EAST OF THE CASCADES AND THE NEXT TROUGH OF
LOW PRESSURE NEAR 130W SLOWLY APPROACHES FROM THE W-SW. THIS MAY
RESULT IN A FEW GUSTS TO 25 KT TONIGHT AND FRI MORNING...BUT IT DOES
NOT APPEAR TO BE ENOUGH TO WARRANT AN ADVISORY. STRONGER SYSTEM
IMPACTS THE WATERS FRI NIGHT AND SAT...LIKELY REQUIRING A SMALL CRAFT
ADVISORY FOR WIND...ESPECIALLY OVER THE OUTER WATERS.
WAVE GUIDANCE DID A PRETTY GOOD JOB INDICATING THE HIGHER SEAS
OVERNIGHT INTO THE MORNING HOURS. SEAS LOOK TO BE RUNNING ABOUT A
FOOT HIGHER THAN THE ENP MODEL AND HAVE ADJUSTED THE TODAY AND
TONIGHT WAVE HEIGHT FORECASTS ACCORDINGLY. SEAS STAY ABOVE 10 FT
THROUGH EARLY FRI MORNING. THE LARGE/LONG PERIOD SWELL WILL RESULT IN
ROUGH COLUMBIA RIVER BAR CONDITIONS WITH BREAKERS DURING THE EBBS.
WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM PST FRIDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
6 AM PST FRIDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1139 AM CST THU JAN 7 2016
.UPDATE...
UPDATED FOR THE 18Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 1105 AM CST THU JAN 7 2016/
UPDATE...
A SHORTWAVE WILL CONTINUE TO MOVE EAST ACROSS THE MIDSOUTH THIS
AFTERNOON. A LINE OF SHOWERS ASSOCIATED WITH THE SHORTWAVE
CURRENTLY STRETCHES FROM CLARKSDALE MISSISSIPPI TO WEST PLAINS
MISSOURI. THE LATEST HRRR SHOWS THIS LINE BREAKING UP AS IT PUSHES
EAST. THIS IS LIKELY DUE TO THE DRY AIR THAT REMAINS IN PLACE OVER
THE AREA. THUS WILL UPDATE TO LOWER POPS.
KRM
DISCUSSION... /ISSUED 404 AM CST THU JAN 7 2016/
SYNOPSIS... MULTIPLE SUCCESSIVE SHORTWAVES WILL TRAVERSE THE MID-
SOUTH OVER THE NEXT SEVERAL DAYS. CLOUDY CONDITIONS AND PERIODS OF
RAIN WILL BE POSSIBLE ALONG WITH SOME THUNDERSTORMS. TEMPERATURES
WILL REMAIN ABOVE NORMAL THROUGH THIS PERIOD BEFORE A MAJOR
COOLDOWN BEGINS SUNDAY AND CONTINUES INTO EARLY NEXT WEEK.
CURRENTLY...AS OF 3AM...
TEMPERATURES ACROSS THE MID-SOUTH RANGE FROM THE MID TO UPPER 20S
ALONG THE TENNESSEE RIVER VALLEY TO THE UPPER 30S WESTWARD. LIGHT
WAA SHOWERS WERE NOTED ON RADAR THIS MORNING...PREDOMINANTLY WEST
OF THE MISSISSIPPI RIVER. LATEST WATER VAPOR IMAGERY SHOWS TWO
DISTINCT SHORTWAVES...WITH ONE LOCATED OVER EAST TEXAS AND THE
OVER SOUTHERN CALIFORNIA. BOTH WAVES ARE PRODUCING CONVECTION AT
THIS HOUR...WITH MODERATE LIGHTNING BEING DETECTED.
SHORT TERM...TODAY THROUGH EARLY SUNDAY MORNING...
AN ACTIVE SOUTHERN BRANCH JET STREAM WILL HEAVILY INFLUENCE OUR
WEATHER THROUGH THIS PERIOD...BRINGING US PERIODS OF RAIN AND SOME
THUNDERSTORMS THROUGH EARLY SUNDAY. A SHORTWAVE LOCATED TO OUR
SOUTHWEST THIS MORNING...WILL LIFT NORTHEAST ACROSS THE
MISSISSIPPI VALLEY THROUGH EARLY FRIDAY MORNING. AS IT DOES...RAIN
WILL OVERSPREAD THE MID-SOUTH. SOME ELEVATED INSTABILITY OVER
NORTH MISSISSIPPI MAY RESULT IN A FEW RUMBLES OF THUNDER THIS
AFTERNOON. TEMPERATURES WILL WARM INTO THE UPPER 40S IN THE
NORTH...WITH MIDDLE 50S TO THE SOUTH. THE AFOREMENTIONED WAVE
WILL LIFT NORTH OF OUR AREA BY FRIDAY AFTERNOON...BRINGING AN END
TO ANY WIDESPREAD RAIN. TEMPERATURES WILL WARM INTO THE 60S
AREAWIDE ON FRIDAY AND WE MAY EVEN SEE A FEW PEEKS OF SUNSHINE
BETWEEN PASSING CLOUDS.
BY FRIDAY NIGHT...A DEEPER AND MORE ROBUST SHORTWAVE WILL DIG
ACROSS THE SOUTHERN PLAINS. AS IT DOES...WEAK CYCLOGENESIS IS
EXPECTED TO OCCUR NEAR THE ARKLAMISS AREA. THE LOW PRESSURE SYSTEM
IS EXPECTED TO TRACK NORTHEAST ACROSS THE MID-SOUTH BY EARLY
SATURDAY AFTERNOON...SPREADING SHOWERS AND THUNDERSTORMS ACROSS
THE AREA. DEWPOINTS AHEAD OF THE SYSTEM LOOK MEAGER AT BEST WITH
VALUES BARELY REACHING INTO THE LOWER 50S IN THE WARM SECTOR OVER
NORTH MISSISSIPPI. HOWEVER...ALL MODELS CONTINUE TO GENERATE
MODEST AMOUNTS OF INSTABILITY OVER THE REGION...WITH ANYWHERE FROM
300 TO 1200 J/KG OF SBCAPE. THE LARGE RANGE SUGGESTS THAT ALL
MODELS ARE HAVING A HARD TIME ESTABLISHING A CLEAR WARM SECTOR
OVER THE REGION BEFORE THE COLD FRONT MOVES THROUGH. NONETHELESS...A
FEW ELEVATED STRONG THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE REGION AS LIFT BECOMES ENHANCED OVER THE REGION DUE TO A
120 MID LEVEL JET ROTATING THROUGH. WILL CONTINUE TO ADVERTISE A
FEW STRONG STORMS POSSIBLE IN THE HWO.
THE STRONG ARCTIC COLD FRONT WILL SWING THROUGH QUICKLY BY
SATURDAY NIGHT...AND ANY LINGERING MOISTURE OVER NORTHERN PARTS OF
WEST TENNESSEE COULD CHANGE OVER TO SNOW OR FLURRIES FOR A BRIEF
HOUR OR SO WITH NO ACCUMULATION EXPECTED. BEHIND THE FRONT...THE
COLDEST AIR OF THIS WINTER THUS FAR WILL ARRIVE AS ARCTIC HIGH
PRESSURE BUILDS IN AT THE SURFACE.
LONG TERM...SUNDAY THROUGH EARLY NEXT...
COLD AND QUIET WEATHER WILL BE THE STORY THROUGH THIS PERIOD.
HIGHS WILL ONLY REACH INTO THE UPPER 30S FOR SUNDAY AND
MONDAY...WITH A GRADUAL MODERATION OF TEMPERATURES THROUGH
MIDWEEK. A SHOT OF REINFORCING COLD AIR WILL OCCUR TUESDAY NIGHT
AS A DRY COLD FRONT MOVES THROUGH.
AC3
&&
.AVIATION...
18Z TAF CYCLE
LOW CLOUDS HAVE MOVED INTO SOUTHERN SECTIONS OF THE FORECAST AREA
AND THESE CLOUDS WILL CONTINUE TO SLOWLY MOVE ACROSS THE REMAINDER
OF THE REGION THIS AFTERNOON AND TONIGHT. LIGHT RAIN IS SLOWLY
MOVING INTO FAR WESTERN SECTIONS AND WILL CONTINUE TO MOVE SLOWLY
EAST THIS AFTERNOON AND TONIGHT. WINDS WILL BE MAINLY FROM THE
SOUTHEAST AT 5 T0 10 KNOTS THIS AFTERNOON AND THEN SHIFT TO THE
SOUTH TONIGHT AT AROUND 10 KNOTS TONIGHT AND WILL CONTINUE THROUGH
FRIDAY MORNING.
ARS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1105 AM CST THU JAN 7 2016
.UPDATE...
A SHORTWAVE WILL CONTINUE TO MOVE EAST ACROSS THE MIDSOUTH THIS
AFTERNOON. A LINE OF SHOWERS ASSOCIATED WITH THE SHORTWAVE
CURRENTLY STRETCHES FROM CLARKSDALE MISSISSIPPI TO WEST PLAINS
MISSOURI. THE LATEST HRRR SHOWS THIS LINE BREAKING UP AS IT PUSHES
EAST. THIS IS LIKELY DUE TO THE DRY AIR THAT REMAINS IN PLACE OVER
THE AREA. THUS WILL UPDATE TO LOWER POPS.
KRM
&&
.DISCUSSION... /ISSUED 404 AM CST THU JAN 7 2016/
SYNOPSIS... MULTIPLE SUCCESSIVE SHORTWAVES WILL TRAVERSE THE MID-
SOUTH OVER THE NEXT SEVERAL DAYS. CLOUDY CONDITIONS AND PERIODS OF
RAIN WILL BE POSSIBLE ALONG WITH SOME THUNDERSTORMS. TEMPERATURES
WILL REMAIN ABOVE NORMAL THROUGH THIS PERIOD BEFORE A MAJOR
COOLDOWN BEGINS SUNDAY AND CONTINUES INTO EARLY NEXT WEEK.
CURRENTLY...AS OF 3AM...
TEMPERATURES ACROSS THE MID-SOUTH RANGE FROM THE MID TO UPPER 20S
ALONG THE TENNESSEE RIVER VALLEY TO THE UPPER 30S WESTWARD. LIGHT
WAA SHOWERS WERE NOTED ON RADAR THIS MORNING...PREDOMINANTLY WEST
OF THE MISSISSIPPI RIVER. LATEST WATER VAPOR IMAGERY SHOWS TWO
DISTINCT SHORTWAVES...WITH ONE LOCATED OVER EAST TEXAS AND THE
OVER SOUTHERN CALIFORNIA. BOTH WAVES ARE PRODUCING CONVECTION AT
THIS HOUR...WITH MODERATE LIGHTNING BEING DETECTED.
SHORT TERM...TODAY THROUGH EARLY SUNDAY MORNING...
AN ACTIVE SOUTHERN BRANCH JET STREAM WILL HEAVILY INFLUENCE OUR
WEATHER THROUGH THIS PERIOD...BRINGING US PERIODS OF RAIN AND SOME
THUNDERSTORMS THROUGH EARLY SUNDAY. A SHORTWAVE LOCATED TO OUR
SOUTHWEST THIS MORNING...WILL LIFT NORTHEAST ACROSS THE
MISSISSIPPI VALLEY THROUGH EARLY FRIDAY MORNING. AS IT DOES...RAIN
WILL OVERSPREAD THE MID-SOUTH. SOME ELEVATED INSTABILITY OVER
NORTH MISSISSIPPI MAY RESULT IN A FEW RUMBLES OF THUNDER THIS
AFTERNOON. TEMPERATURES WILL WARM INTO THE UPPER 40S IN THE
NORTH...WITH MIDDLE 50S TO THE SOUTH. THE AFOREMENTIONED WAVE
WILL LIFT NORTH OF OUR AREA BY FRIDAY AFTERNOON...BRINGING AN END
TO ANY WIDESPREAD RAIN. TEMPERATURES WILL WARM INTO THE 60S
AREAWIDE ON FRIDAY AND WE MAY EVEN SEE A FEW PEEKS OF SUNSHINE
BETWEEN PASSING CLOUDS.
BY FRIDAY NIGHT...A DEEPER AND MORE ROBUST SHORTWAVE WILL DIG
ACROSS THE SOUTHERN PLAINS. AS IT DOES...WEAK CYCLOGENESIS IS
EXPECTED TO OCCUR NEAR THE ARKLAMISS AREA. THE LOW PRESSURE SYSTEM
IS EXPECTED TO TRACK NORTHEAST ACROSS THE MID-SOUTH BY EARLY
SATURDAY AFTERNOON...SPREADING SHOWERS AND THUNDERSTORMS ACROSS
THE AREA. DEWPOINTS AHEAD OF THE SYSTEM LOOK MEAGER AT BEST WITH
VALUES BARELY REACHING INTO THE LOWER 50S IN THE WARM SECTOR OVER
NORTH MISSISSIPPI. HOWEVER...ALL MODELS CONTINUE TO GENERATE
MODEST AMOUNTS OF INSTABILITY OVER THE REGION...WITH ANYWHERE FROM
300 TO 1200 J/KG OF SBCAPE. THE LARGE RANGE SUGGESTS THAT ALL
MODELS ARE HAVING A HARD TIME ESTABLISHING A CLEAR WARM SECTOR
OVER THE REGION BEFORE THE COLD FRONT MOVES THROUGH. NONETHELESS...A
FEW ELEVATED STRONG THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
ENTIRE REGION AS LIFT BECOMES ENHANCED OVER THE REGION DUE TO A
120 MID LEVEL JET ROTATING THROUGH. WILL CONTINUE TO ADVERTISE A
FEW STRONG STORMS POSSIBLE IN THE HWO.
THE STRONG ARCTIC COLD FRONT WILL SWING THROUGH QUICKLY BY
SATURDAY NIGHT...AND ANY LINGERING MOISTURE OVER NORTHERN PARTS OF
WEST TENNESSEE COULD CHANGE OVER TO SNOW OR FLURRIES FOR A BRIEF
HOUR OR SO WITH NO ACCUMULATION EXPECTED. BEHIND THE FRONT...THE
COLDEST AIR OF THIS WINTER THUS FAR WILL ARRIVE AS ARCTIC HIGH
PRESSURE BUILDS IN AT THE SURFACE.
LONG TERM...SUNDAY THROUGH EARLY NEXT...
COLD AND QUIET WEATHER WILL BE THE STORY THROUGH THIS PERIOD.
HIGHS WILL ONLY REACH INTO THE UPPER 30S FOR SUNDAY AND
MONDAY...WITH A GRADUAL MODERATION OF TEMPERATURES THROUGH
MIDWEEK. A SHOT OF REINFORCING COLD AIR WILL OCCUR TUESDAY NIGHT
AS A DRY COLD FRONT MOVES THROUGH.
AC3
&&
.AVIATION...
12Z TAFS
CHANGES EXPECTED THIS TAF CYCLE AS DISTURBANCE LIFTS THROUGH. VFR
CIGS WILL PERSIST THROUGH THE MORNING...WITH A THREAT FOR MVFR AT
TUP BEFORE NOON. THIS AFTERNOON/EVENING AS RAIN BAND LIFTS NORTH
CIGS WILL LOWER TO MVFR AND IFR THROUGH THE REMAINING TAF PERIOD.
EAST TO SOUTHEAST WINDS AT 3-7 KTS WILL INCREASE TO 7-9 KTS.
JAB
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
COMPLEX SCENARIO UNFOLDING WITH PRECIPITATION TYPES...ACCUMULATIONS
AND IMPACT. WATCHING THIS MORNING CLOSELY FOR ANY HINT OF IMPACT
FOR AN UPGRADE TO AN ADVISORY FOR FREEZING DRIZZLE...BECAUSE IT
IS OUT THERE OVER IOWA.
WATCHING SNOW MOVE THROUGH THE AREA AND BACK EDGE IS NEARING A
MSP-LSE-RFD LINE AT 09Z. BEHIND IT...REPORTS THROUGH CENTRAL IA
ARE DRIZZLE IS OCCURRING AND DEPENDING ON SURFACE
TEMPERATURES...ICING. WFO DES MOINES HAS HAD DRIZZLE FOR MANY
HOURS WITH ICING TO THE TREES BUT NOT THE GROUND LEVEL SURFACES.
THEY ALSO REPORT VSBY RESTRICTION IN IA MAINLY DUE TO DZ. ELEVATED
ICING SENSOR AT KDSM IS SHOWING SOME ICE ACCUMULATION. THIS
DRIZZLE AREA HAS A WELL FORECAST LEADING EDGE COINCIDENT WITH THE
IR CLOUD TOP WARMING REGION BEHIND THE SNOW ECHOES. KDSM HAS SEEN
-8C TO -10C CLOUD TOP TEMPS ALL NIGHT SUGGESTIVE OF AN ALL LIQUID
SURFACE-BASED SUPERCOOLED LAYER. THIS IS ALL SHIFTING INTO WI
WITH NO AIR MASS CHANGE THROUGH THE MORNING...AND LIGHT VERTICAL
MOTION IN THE 2KM DEEP SATURATED AND SUPERCOOLED LIQUID LAYER.
CALLS TO NERN IA SHERIFFS DO STATE THAT DRIZZLE IS HIT AND MISS
OUT THERE WITH SNOW COVERED ROADS. THE PROBLEM IS THEY ALSO SAID
THAT ICING IS OCCURRING ON ROAD SURFACES. HRRR AND RAP ARE
SUGGESTIVE WE WILL CONTINUE VERTICAL MOTION IN THE
LAYER...POSSIBLY TO -5 UB/S THROUGH THE MORNING...WITH A
DIMINISHING TREND AT LEAST FOR THE NORTH LATER THIS MORNING.
BELIEVE DRIZZLE AND FZDZ WILL BE AROUND THIS MORNING WITH VERY
LIGHT ACCUMULATIONS. WILL NEED TO UPGRADE SPS TO AN ADVISORY FOR
AT LEAST NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THE MORNING.
CANNOT BE SURE THIS DRIZZLE WILL BE ENDING THIS
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN FORECAST AREA AND THUS
LINGERED HIGHER PRECIPITATION CHANCES THERE ALL AFTERNOON...WITH A
SLIGHT BREAK TO THE NORTH.
LATER IN THE AFTERNOON AND TONIGHT WE SEE THE NEXT ROUND OF
PRECIPITATION MOVE IN FROM THE SOUTH ASSOCIATED WITH THE SHORTWAVE
TROUGH OVER TX AT 0930Z. THERE ARE NO REAL SURPRISES IN THIS
FORECAST AND VERY LITTLE CHANGE WAS MADE FROM LATER THURSDAY
THROUGH FRIDAY. A NICE RAIN/SNOW BAND IS EXPECTED AS MOISTURE
TRANSPORT CONVERGENCE ON THE NOSE OF THE LOW-LEVEL FLOW MOVES IN
LATE IN THE DAY WITH PRECIPITABLE WATER VALUES OVER 0.50 INCHES
WHICH IS ABOUT 200 PERCENT NORMAL. THIS FIRST BAND IS FAIRLY
TRANSIENT AND WITH THE OPEN WAVE ALOFT...DEFORMATION BANDING
DOESNT SEEN TO BE AN ISSUE...SO IT IS MULTIPLE SURGES OF WEAK-
MODERATE WARM ADVECTION WITHOUT UPPER LEVEL QVECTOR CONVERGENCE
SUPPORT...BUT IN THE MIDST OF ABUNDANT MOISTURE. SO...A
CLOUDY/RAINY/SNOWY/DRIZZLY PERIOD.
HAVENT MOVED THE RAIN/SNOW LINE MUCH IN THIS FORECAST AND THE 1 TO
3 INCH SNOW ACCUMULATIONS STILL LOOK GOOD AND HIGHLY DEPEND ON
THE LOCATION AND TEMPERATURES. VALLEY LOCATIONS NORTH AND WEST OF
LA CROSSE WILL SEE THE LOWER END OF THOSE VALUES...WHILE COOLER
ELEVATED LOCATIONS AND NORTH-CENTRAL WI NORTH OF HIGHWAY 29...WILL
GET THE HIGHER END. THIS SHOULD NOT BE MUCH OF AN IMPACT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
FRIDAY NIGHT AND SATURDAY...STILL SOME ACTIVE PRECIPITATION
CHANCES FRIDAY NIGHT AS THE ARCTIC FRONT COMES RIPPING IN. ALL
PRECIPITATION WILL CHANGE TO SNOW...AND COLD ADVECTION WILL BE
VERY NOTICEABLE FOR SATURDAY WITH FALLING TEMPERATURES AND WINDS
15 TO 25 MPH.
SUNDAY THROUGH WEDNESDAY...A COLD PERIOD WE HAVENT SEEN THIS
WINTER YET. IT IS STILL LOOKING LIKE WIND CHILL ADVISORIES WILL BE
NEEDED FOR SOME SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY NOON)
ISSUED AT 1135 AM CST THU JAN 7 2016
THIS TAF PERIOD WILL BE DOMINATED BY IFR/LIFR CIGS/VSBYS AS A WARM
AND MOIST AIRMASS IS PUSHED NORTHWARD OVER THE SNOW COVERED
LANDSCAPE. THE LIFR CIGS/VSBYS IN BR/FG WILL BE MORE COMMON OVER THE
HIGHER TERRAIN AREAS /KRST/...WHILE MS/WI RIVER VALLEYS /KLSE/ WILL
BE MORE IFR PERHAPS BRIEF PERIODS OF MVFR. THE NEXT SYSTEM LIFTING
TOWARD AND ACROSS THE AREA WILL SPREAD ANOTHER ROUND OF PRECIP
NORTHEAST ACROSS THE TAF SITES TONIGHT AND MUCH OF FRI. LOWER LEVEL
THEMAL PROFILES IN MODEL SOUNDINGS AND BOUNDARY LAYER TEMPS INDICATE
MOST OF THIS WOULD BE -RA AT KLSE...WITH A -RA/-SN MIX OR -SN AT
KRST. SLUSHY SNOW ACCUMULATIONS TONIGHT INTO FRI MORNING MAY IMPACT
AIRPORT OPS AT KRST...WHILE LITTLE IF ANY SNOWFALL IS EXPECTED AT
KLSE. BOUNDARY LAYER TEMPS TONIGHT/FRI MORNING ARE TRENDING WARM
ENOUGH THAT ANY POTENTIAL ICING THREAT IS QUITE SMALL. CIGS/VSBYS IN
THE BR/FG AND ANY PRECIP SHOULD START TO IMPROVE FRI AFTERNOON AS
THE SYSTEM PASSES AND WINDS SWING AROUND TO THE NORTH AND
NORTHWEST...BRINGING IN A DRYING LOWER LEVEL AIRMASS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1102 AM CST THU JAN 7 2016
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
COMPLEX SCENARIO UNFOLDING WITH PRECIPITATION TYPES...ACCUMULATIONS
AND IMPACT. WATCHING THIS MORNING CLOSELY FOR ANY HINT OF IMPACT
FOR AN UPGRADE TO AN ADVISORY FOR FREEZING DRIZZLE...BECAUSE IT
IS OUT THERE OVER IOWA.
WATCHING SNOW MOVE THROUGH THE AREA AND BACK EDGE IS NEARING A
MSP-LSE-RFD LINE AT 09Z. BEHIND IT...REPORTS THROUGH CENTRAL IA
ARE DRIZZLE IS OCCURRING AND DEPENDING ON SURFACE
TEMPERATURES...ICING. WFO DES MOINES HAS HAD DRIZZLE FOR MANY
HOURS WITH ICING TO THE TREES BUT NOT THE GROUND LEVEL SURFACES.
THEY ALSO REPORT VSBY RESTRICTION IN IA MAINLY DUE TO DZ. ELEVATED
ICING SENSOR AT KDSM IS SHOWING SOME ICE ACCUMULATION. THIS
DRIZZLE AREA HAS A WELL FORECAST LEADING EDGE COINCIDENT WITH THE
IR CLOUD TOP WARMING REGION BEHIND THE SNOW ECHOES. KDSM HAS SEEN
-8C TO -10C CLOUD TOP TEMPS ALL NIGHT SUGGESTIVE OF AN ALL LIQUID
SURFACE-BASED SUPERCOOLED LAYER. THIS IS ALL SHIFTING INTO WI
WITH NO AIR MASS CHANGE THROUGH THE MORNING...AND LIGHT VERTICAL
MOTION IN THE 2KM DEEP SATURATED AND SUPERCOOLED LIQUID LAYER.
CALLS TO NERN IA SHERIFFS DO STATE THAT DRIZZLE IS HIT AND MISS
OUT THERE WITH SNOW COVERED ROADS. THE PROBLEM IS THEY ALSO SAID
THAT ICING IS OCCURRING ON ROAD SURFACES. HRRR AND RAP ARE
SUGGESTIVE WE WILL CONTINUE VERTICAL MOTION IN THE
LAYER...POSSIBLY TO -5 UB/S THROUGH THE MORNING...WITH A
DIMINISHING TREND AT LEAST FOR THE NORTH LATER THIS MORNING.
BELIEVE DRIZZLE AND FZDZ WILL BE AROUND THIS MORNING WITH VERY
LIGHT ACCUMULATIONS. WILL NEED TO UPGRADE SPS TO AN ADVISORY FOR
AT LEAST NORTHEAST IOWA AND SOUTHWEST WISCONSIN FOR THE MORNING.
CANNOT BE SURE THIS DRIZZLE WILL BE ENDING THIS
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN FORECAST AREA AND THUS
LINGERED HIGHER PRECIPITATION CHANCES THERE ALL AFTERNOON...WITH A
SLIGHT BREAK TO THE NORTH.
LATER IN THE AFTERNOON AND TONIGHT WE SEE THE NEXT ROUND OF
PRECIPITATION MOVE IN FROM THE SOUTH ASSOCIATED WITH THE SHORTWAVE
TROUGH OVER TX AT 0930Z. THERE ARE NO REAL SURPRISES IN THIS
FORECAST AND VERY LITTLE CHANGE WAS MADE FROM LATER THURSDAY
THROUGH FRIDAY. A NICE RAIN/SNOW BAND IS EXPECTED AS MOISTURE
TRANSPORT CONVERGENCE ON THE NOSE OF THE LOW-LEVEL FLOW MOVES IN
LATE IN THE DAY WITH PRECIPITABLE WATER VALUES OVER 0.50 INCHES
WHICH IS ABOUT 200 PERCENT NORMAL. THIS FIRST BAND IS FAIRLY
TRANSIENT AND WITH THE OPEN WAVE ALOFT...DEFORMATION BANDING
DOESNT SEEN TO BE AN ISSUE...SO IT IS MULTIPLE SURGES OF WEAK-
MODERATE WARM ADVECTION WITHOUT UPPER LEVEL QVECTOR CONVERGENCE
SUPPORT...BUT IN THE MIDST OF ABUNDANT MOISTURE. SO...A
CLOUDY/RAINYSNOWY/DRIZZLY PERIOD.
HAVENT MOVED THE RAIN/SNOW LINE MUCH IN THIS FORECAST AND THE 1 TO
3 INCH SNOW ACCUMULATIONS STILL LOOK GOOD AND HIGHLY DEPEND ON
THE LOCATION AND TEMPERATURES. VALLEY LOCATIONS NORTH AND WEST OF
LA CROSSE WILL SEE THE LOWER END OF THOSE VALUES...WHILE COOLER
ELEVATED LOCATIONS AND NORTHCENTRAL WI NORTH OF HIGHWAY 29...WILL
GET THE HIGHER END. THIS SHOULD NOT BE MUCH OF AN IMPACT.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM CST THU JAN 7 2016
FRIDAY NIGHT AND SATURDAY...STILL SOME ACTIVE PRECIPITATION
CHANCES FRIDAY NIGHT AS THE ARCTIC FRONT COMES RIPPING IN. ALL
PRECIPITATION WILL CHANGE TO SNOW...AND COLD ADVECTION WILL BE
VERY NOTICEABLE FOR SATURDAY WITH FALLING TEMPERATURES AND WINDS
15 TO 25 MPH.
SUNDAY THROUGH WEDNESDAY...A COLD PERIOD WE HAVENT SEEN THIS
WINTER YET. IT IS STILL LOOKING LIKE WIND CHILL ADVISORIES WILL BE
NEEDED FOR SOME SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 510 AM CST THU JAN 7 2016
AS THE FIRST SHORT WAVE TROUGH MOVES AWAY FROM THE REGION...ICE IN
THE CLOUDS IS BEING LOST WHICH IS ALLOWING FOR SOME LIGHT FREEZING
DRIZZLE TO OCCUR. WITH THE FLOW REMAINING SOUTHWEST...SOME
ISENTROPIC UP GLIDE WILL CONTINUE THROUGH THE DAY FROM THE WARM
AIR ADVECTION. THIS WILL CREATE ENOUGH LIFT THROUGH THE SATURATED
LAYER TO KEEP THE FREEZING DRIZZLE GOING UNTIL TEMPERATURES WARM
TO ABOVE 0C AND SWITCH THIS OVER TO DRIZZLE. THE NEXT SHORT WAVE
TROUGH WILL APPROACH THE AREA TONIGHT AND GENERATE SOME BETTER
LIFT THROUGH THE COLUMN. THIS WILL ALSO CREATE A DEEPER SATURATED
LAYER AND ALLOW ICE TO BE REINTRODUCED INTO THE CLOUDS. THIS WILL
CHANGE THE DRIZZLE BACK OVER TO RAIN OR SNOW EARLY THIS
EVENING...BASED ON WHAT THE LOW LEVEL TEMPERATURES ARE. IT
CURRENTLY LOOKS LIKE KRST SHOULD BE COLD ENOUGH FOR MAINLY SNOW
WHILE KLSE WILL BE JUST A TOUCH WARMER FOR RAIN OR A RAIN SNOW
MIX. WITH ALL THIS PRECIPITATION...IFR CEILINGS WILL DOMINATE THE
PERIOD. THE VISIBILITY WILL BE MVFR TO IFR UNTIL THE HEAVIER
PRECIPITATION MOVES IN THIS EVENING WHEN BOTH SITES SHOULD HAVE
IFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04