Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/15/16
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
202 PM PST WED JAN 13 2016
.SYNOPSIS...
FAIR WEATHER THROUGH THIS EVENING WITH A FEW PASSING HIGH CLOUDS AND
TEMPERATURES SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. A WEAK
WEATHER SYSTEM WILL BRING INCREASING LOW CLOUDS WEST OF THE
MOUNTAINS TONIGHT WITH A SLIGHT CHANCE OF SPRINKLES. AS HIGH
PRESSURE RIDGE BUILDS OVER SOUTHERN CALIFORNIA...MILD AND DRY
WEATHER WILL LIKELY PREVAIL FROM THURSDAY THROUGH MONDAY OF NEXT
WEEK. A WEATHER DISTURBANCE WILL BRING A SLIGHT CHANCE OF COASTAL
AND VALLEY RAIN SHOWERS AND MOUNTAIN SNOW ON TUESDAY.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AT 1 PM PST...ON VISIBLE SATELLITE IMAGERY...SCATTERED HIGH CIRRUS
CLOUDS ABOVE 20000 FEET COULD BE OBSERVED STREAMING ACROSS SOUTHERN
CALIFORNIA WITH SCATTERED TO BROKEN LOW CLOUDS CLOUDS PUSHING INTO
OUR OUTER WATERS ZONE. THE METAR AT SAN CLIMENTE REPORTED A CEILING
OF 1100 FEET MSL. SURFACE PRESSURE GRADIENTS CONTINUE TO STRENGTHEN
WITH SAN-IPL GRADIENT NOW AT +2.2 MB.
MILD WEATHER WILL PREVAIL THIS EVENING WITH TEMPERATURES REGION WIDE
NEAR OR SLIGHTLY BELOW NORMAL. AFTER SUN DOWN...SURFACE PRESSURE
GRADIENTS WILL TREND STRONGER ONSHORE AND SCATTERED LOW CLOUDS WILL
PUSH INTO THE COASTAL AND VALLEY REGIONS. BY TONIGHT...MODELS PROG A
WEAK COLD FRONT TO SLIDE SOUTH AND EASTWARD TOWARDS SOUTHERN
CALIFORNIA. THIS FRONT WILL AID IN DEEPENING THE MARINE LAYER AND
BRINING A SLIGHT CHANCE OF SPRINKLES TO THE AREA. WITH THE LOCAL
WRF...NAM4...AND HRRR ARE ALL BACKING OFF ON THE PRECIP...WE WILL BE
LUCKY TO PICK UP MORE THAN 0.02 INCHES OF RAIN AT ANY GIVEN LOCATION.
HOWEVER...THIS PASSING FEATURE WILL STILL WARRANT A SLIGHT CHANCE OF
SPRINKLES WEST OF THE MOUNTAINS FROM THIS EVENING TO EARLY THURSDAY
MORNING.
FROM THURSDAY THROUGH SATURDAY...WEAK RIDGING WILL MOVE OVER THE
DESERT SOUTHWEST...CONTINUING THE NEAR AVERAGE TEMPERATURES AND A
FEW PASSING MID AND HIGH LEVEL CLOUDS. ONSHORE FLOW WILL BRIEFLY
STRENGTHEN ON FRIDAY GENERATING GUSTY WEST WINDS ON THE MOUNTAIN
RIDGETOPS AND DESERT SLOPES.
SUNDAY THROUGH MID NEXT WEEK...LONG RANGE MODELS SHOW A LOW
PRESSURE SYSTEM MOVING THROUGH NORTHERN CALIFORNIA AND THE
PACIFIC NORTHWEST. SOUTHERN CALIFORNIA WILL BE ON THE SOUTHERN
FRINGES OF THIS SYSTEM...LEAVING SO CAL WITH MILD
WEATHER...INCREASED ONSHORE FLOW....AND INTERMITTENT CLOUDINESS.
THE 12Z GFS AND 12Z ECMWF BOTH PLACE LIGHT TO MODERATE PRECIP OVER
PORTIONS OF SOUTHWEST CALIFORNIA ON TUESDAY. HAVE ADDED A SLIGHT
CHANCE OF PRECIPITATION OVER AND WEST OF THE MOUNTAINS FROM
TUESDAY MORNING THROUGH EARLY TUESDAY NIGHT. ANOTHER RIDGE WILL
BUILD IN BEHIND THIS QUICK MOVING TROUGH.
&&
.AVIATION...
132100Z...SCT-BKN CLOUDS AOA 10000 FT MSL THROUGH THIS AFTERNOON.
LOWER CLOUDS AROUND 2000-3000 FEET MSL WILL DEVELOP OVER THE COASTAL
BASIN THIS EVENING AFTER 01Z. COVERAGE COULD BE PATCHY
THOUGH...GIVEN THE EXISTING HIGH CLOUDS. A FEW SPRINKLES ARE
POSSIBLE WEST OF THE MOUNTAINS BETWEEN AROUND 14/04-12Z. PARTLY
CLOUDY WITH HIGH CLOUDS THROUGH THURSDAY AFTERNOON.
&&
.MARINE...
100 PM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SATURDAY.
RAPIDLY BUILDING WEST NORTHWEST SWELL ON SUNDAY MAY CREATE HAZARDOUS
SEAS IN THE OUTER WATERS.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...JT
AVIATION/MARINE...TS
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
130 PM PST WED JAN 13 2016
.SYNOPSIS...
COOLER THAN NORMAL TEMPERATURES TO CONTINUE THROUGH THE WEEKEND AS
A SERIES OF WEAK WEATHER SYSTEMS MOVES THROUGH. RAIN CHANCES WILL
BE CONFINED MOSTLY TO SANTA BARBARA AND NORTH. A BETTER CHANCE FOR
RAIN IN ALL AREAS NEXT TUESDAY.
&&
.SHORT TERM (TODAY-SAT)...OUR WEAK FRONT FOR TODAY WASHED OUT EVEN
FASTER THAN EXPECTED AND IS STRUGGLING TO EVEN GENERATE CLOUDS
ACROSS THE SRN PORTION OF THE FORECAST AREA THIS AFTERNOON. HAVE
REMOVED POPS FROM THE FORECAST AND DECREASED CLOUDS QUITE A BIT
OVERNIGHT. THE ONLY EXCEPTION TO THAT IS THE INTERIOR PORTION OF
SLO COUNTY WHICH WILL LIKELY SEE LOW LVL MOISTURE ADVECTING IN
FROM THE SAN JOAQUIN VALLEY LATER TONIGHT CREATING AREAS OF LOW
CLOUDS AND FOG. OTHERWISE JUST PARTLY CLOUDY SKIES.
POST-FRONTAL NORTHWEST WINDS WILL DEVELOP THIS EVENING BUT TODAY`S
MODELS CONTINUED THE DECREASING TREND FROM EARLIER RUNS AND HAVE
OPTED TO KEEP WINDS BELOW ADVISORY LEVELS. STRONGEST WINDS WILL BE
UP IN THE GRAPEVINE, ANTELOPE VALLEY, AND SRN SBA COUNTY.
QUIET WEATHER THU WITH JUST SOME PASSING HIGH CLOUDS. HIGHS ABOUT 5
DEGREES COOLER THAN NORMAL.
ANOTHER WEAK FRONTAL BOUNDARY WILL INCREASE CLOUDS AND RAIN
CHANCES NORTH OF PT CONCEPTION THURSDAY NIGHT INTO FRIDAY MORNING,
THOUGH THE ECMWF IS EVEN WEAKER THAN THE GFS AND BOTH KEEP MOST OF
THE ENERGY WELL TO THE NORTH. SO AT BEST JUST SOME LIGHT PRECIP
NORTHERN AREAS AND SOME CLOUDS IN THE SOUTH.
A RIDGE WILL POP UP ALONG THE WEST COAST FRIDAY AFTERNOON THROUGH
EARLY SATURDAY WHILE A COLD FRONT APPROACHES FROM THE WEST. ALL
THE MODELS SHOW SOME LOW LVL MOISTURE MOVING INTO THE CENTRAL
COAST SATURDAY MORNING WELL AHEAD OF THE COLD FRONT, THOUGH ONLY
THE GFS SPITS OUT ANY PRECIP ALONG THE CENTRAL COAST AS LIFT IS
MINIMAL UNDER THE RIDGE AXIS. WORTHY OF A CHANCE OF RAIN NORTHERN
AREAS BUT NOT MUCH MORE THAN THAT.
THE RIDGE WILL SHIFT EAST SATURDAY BUT NOT BEFORE TAKING A SIZABLE
BITE OUT OF THE APPROACHING COLD FRONT AND THE MODELS PRETTY MUCH
ALL AGREE THERE WON`T BE ENOUGH LEFT TO GENERATE ANYTHING
MEASURABLE SATURDAY NIGHT, BUT MAYBE A FEW SPRINKLES UP NORTH.
.LONG TERM (SUN-WED)...THE RIDGE RETURNS SUNDAY BUT IT WILL BE
ACCOMPANIED BY A FAIR AMOUNT OF HIGH CLOUDS SO PARTLY CLOUDY MOST
AREAS. ON MONDAY A WEAKENING FRONTAL BOUNDARY WILL AGAIN WASH OUT
OVER THE CENTRAL COAST BUT IT MAY HOLD TOGETHER JUST LONG ENOUGH
TO BRING A FEW SPRINKLES OR LIGHT SHOWERS NORTH OF PT CONCEPTION.
PARTLY CLOUDY AND DRY IN THE SOUTH.
MONDAY NIGHT AND TUESDAY A SLIGHTLY DEEPER TROF WILL MOVE THROUGH
NRN CALIFORNIA AND STANDS A BETTER CHANCE OF BRING AT LEAST SOME
LIGHT RAIN TO THE AREA, THOUGH HERE AGAIN THERE ARE SIGNIFICANT
MODEL DIFFERENCES. THE GFS IS PRETTY WET, THOUGH WHY IS VERY
UNCLEAR AS ALMOST ALL THE DYNAMICS ARE NORTH OF THE BAY AREA AND
THERE IS NO PARTICULARLY GOOD REASON WHY THE FRONT SHOULD GENERATE
SUCH PROLIFIC OROGRAPHIC ENHANCEMENT. VASTLY PREFER THE MORE
REASONABLE ECMWF SOLUTION DURING THIS TIME PERIOD WHICH STILL
BRINGS AT LEAST LIGHT RAIN INTO LA COUNTY TUESDAY BUT ABOUT 90%
LESS PRECIP THAN THE GFS.
ALL MODELS SHOW A SHARP RIDGE RETURNING TUESDAY NIGHT INTO
WEDNESDAY FOR DRY WEATHER BUT STILL BELOW NORMAL TEMPS.
&&
.AVIATION...13/1800Z
MID/UPPER LEVEL TROUGH OF LOW PRESSURE OVER THE AREA WILL SHIFT
EAST AND A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE AREA. UPPER LEVEL
MODERATE WEST WINDS WILL BECOME MODERATE NORTHWEST 14/06Z WHILE MID LEVEL
LIGHT TO MODERATE NORTHWEST WINDS PREVAIL OVER THE AREA.
A COLD FRONT WILL DISSIPATE OVER THE SLO/SB COUNTIES THROUGH 13/20Z.
FREEZING LEVEL THIS MORNING WAS 10KFT AND LITTLE CHANGE IS EXPECTED
THURSDAY.
MARINE LAYER AT LAX AT 1700Z IS NONE.
KLAX...CHANCE CIGS 050 AND CIGS 015 AT TIMES BETWEEN 14/00-14/04Z.
CHANCE CIGS 020 BETWEEN 14/11-14/18Z.
KBUR...CHANCE CIGS 028 AT TIMES BETWEEN 14/11-14/15Z.
VIRTUALLY CERTAIN - 95-100%
VERY LIKELY - 80-95%
LIKELY - 60-80%
CHANCE - 30-60%
VERY UNLIKELY - 20% OR LESS
&&
.MARINE...13/200 PM.
NORTHWEST WINDS WILL LIKELY DEVELOP AND INCREASE THIS EVENING AND
SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED FROM POINT SAL TO
SOUTH OF SAN NICOLAS ISLAND TONIGHT THROUGH THURSDAY MORNING.
OTHERWISE SMALL CRAFT ADVISORY CONDITIONS FOR HAZARDOUS SEAS WILL
CONTINUE FROM PIEDRAS BLANCAS TO SAN CLEMENTE ISLAND THROUGH
TONIGHT. THE SEAS ARE EXPECTED TO SUBSIDE BELOW 10 FEET BRIEFLY
THURSDAY NIGHT AND THEN REBUILD FRIDAY. A 947 MB LOW WITH A GALE
AND STORM FORCE WIND FETCH ORIENTED BETWEEN 280-290 DEGREES
RELATIVE TO VENTURA COUNTY WILL DEVELOP NORTH OF THE HAWAIIAN
ISLANDS TONIGHT THROUGH THURSDAY. THE SEAS ARE EXPECTED TO BUILD
TO 45 FEET SLIGHTLY LARGER THAN THE SEAS THAT WERE GENERATED LAST
WEEK SATURDAY AND THAT PEAKED NEAR SHORE TUESDAY. THE SWELLS WILL
BUILD SATURDAY NIGHT AND SMALL CRAFT ADVISORY FOR HAZARDOUS SEA
CONDITIONS ARE EXPECTED FROM PIEDRAS BLANCAS TO SAN CLEMENTE
ISLAND SUNDAY THROUGH NEXT WEEK MONDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
HIGH SURF ADVISORY (SEE LAXCFWLOX).
&&
$$
PUBLIC...MW
AVIATION/MARINE...30
WWW.WEATHER.GOV/LOSANGELES
Area Forecast Discussion
National Weather Service Sacramento CA
1040 AM PST WED JAN 13 2016
.SYNOPSIS...
Showers and thunderstorms today, some severe thunderstorms possible
with potential for isolated weak tornadoes, hail, and brief heavy
rain. Accumulating snow in the mountains will impact travel today.
Wet pattern continues for NorCal, potentially very wet early next
week.
&&
.DISCUSSION...
An upper level trough with a surface front is moving through
the area today. This is bringing snow showers to the mountains,
with 2-4 inches of snow so far measured over 6000 feet. Snow
levels are around 5500 feet and falling, reaching below 5000 feet
later today. Chain restrictions are in effect for mountain roads
such as I80 and Highway 50. A Winter Weather Advisory continues
through midnight tonight.
Main issue for today is the potential for strong thunderstorms
this afternoon in the wake of the frontal passage. Scattered
showers have been developing over the area this morning, and
instability has been enough for a few isolated thunderstorms
already. A couple of these passed through the Sacramento metro
area dropping small hail and a brief period of heavy rain. Radar
shows a line of storms moving onshore by Eureka, and this line is
shifting eastward.
Strong storms are possible this afternoon overthe forecast area
with significant low level shear for rotating storms and possible
even weak tornadoes. If there are sufficient breaks in the clouds,
solar heating will give an additional boost to instability. The
best chance for severe weather currently appears to be around
Butte, eastern Tehama and Glenn, and western Yuba counties. Cloud
cover over Shasta County may inhibit severe storm development,
though the HRRR model suggests lines of convection with heavy rain
developing. Burn areas in the Sierra and Lake County could see
brief periods of heavy rain, but quick storm motion should limit
the potential for debris slides.
Gusty winds continue this morning, but mainly peaked overnight and
the early morning hours. Have allowed the Wind Advisory to expire
as winds are expected to continue to decrease through the day. EK
&&
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
Sunday is expected to be a transitional period between systems
with relatively flat upper level ridging briefly builds, but some
precipitation chances remain northward of I-80. The next wet system
comes into NorCal Sunday night into Tuesday. Models diverge on the
pattern Wednesday next week with more ridging introduced. We
tailored back precipitation chances and coverage to mainly the
mountains, especially the northern mountains. JClapp
&&
.AVIATION...
Expect scattered showers to continue into the early evening. Isolated
thunderstorms will be possible this afternoon central to north
Sac Valley. Local areas of MVFR conditions could accompany
storms. South winds 10 to 20 kt local gusts to 30 kt will be
possible across the Valley north of Sacramento.
&&
.STO Watches/Warnings/Advisories...
Winter Weather Advisory until midnight PST tonight for West
Slope Northern Sierra Nevada-Western Plumas County/Lassen Park.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
931 AM PST WED JAN 13 2016
.SYNOPSIS...
FAIR SKIES TODAY WITH A FEW PASSING HIGH CLOUDS AND TEMPERATURES
SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR. A WEAK WEATHER SYSTEM
WILL BRING INCREASING LOW CLOUDS WEST OF THE MOUNTAINS TONIGHT WITH
A SLIGHT CHANCE OF SPRINKLES. AS A WEAK HIGH PRESSURE RIDGE BUILDS
OVER THE WEST...MILD AND DRY WEATHER WILL LIKELY PREVAIL FROM
THURSDAY THROUGH MID NEXT WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
AT 9 AM PST...THE 12Z KNKX SOUNDING SHOWED DRY AIR FROM THE SURFACE
UP THROUGH AROUND 25000 FEET MSL...AND NORTHWEST WINDS AT ALL
LEVELS. IR SATELLITE INDICATED A WELL DEFINED STORM SYSTEM CENTERED
OFF OF THE OREGON COAST WITH A COLD FRONT EXTENDING SOUTHWARD
TOWARDS POINT CONCEPTION. THIS FEATURE WILL BE THE MAIN THE FOCUS
OVER THE NEXT 24 HOURS.
MILD WEATHER WILL CONTINUE THROUGH THIS EVENING WITH TEMPERATURES
REGION WIDE NEAR OR SLIGHTLY BELOW NORMAL. BY TONIGHT...MODELS PROG
THE AFOREMENTIONED COLD FRONT TO WEAKEN CONSIDERABLY AND SLIDE SOUTH
AND EASTWARD TOWARDS SOUTHERN CALIFORNIA. AFTER SUN DOWN SURFACE
PRESSURE GRADIENTS WILL TREND STRONGER ONSHORE AND SCATTERED LOW
CLOUDS WILL PUSH INTO THE COASTAL REGIONS. WITH THE LOCAL
WRF...NAM4...AND HRRR ARE ALL BACKING OFF ON THE PRECIP...WE WILL BE
LUCKY TO PICK UP MORE THAN 0.02 INCHES OF RAIN AT ANY GIVEN LOCATION.
HOWEVER...THIS PASSING FEATURE WILL STILL WARRANT A SLIGHT CHANCE OF
SPRINKLES WEST OF THE MOUNTAINS FROM THIS EVENING TO EARLY THURSDAY
MORNING.
FROM THURSDAY THROUGH THE WEEKEND...WEAK RIDGING WILL MOVE OVER THE
DESERT SOUTHWEST...CONTINUING THE NEAR AVERAGE TEMPERATURES AND A
FEW PASSING MID AND HIGH LEVEL CLOUDS. ONSHORE FLOW WILL BRIEFLY
STRENGTHEN ON FRIDAY GENERATING GUSTY WEST WINDS ON THE MOUNTAIN
RIDGETOPS AND DESERT SLOPES.
EARLY/MID NEXT WEEK...ANOTHER ROUND OF WEAK RIDGES AND TROUGHS WILL
PASS OVER CALIFORNIA. BOTH THE 12Z GFS AND 00Z ECMWF SHOW A RATHER
STRONG AND STAGNANT LONG WAVE TROUGH CENTERED OVER THE GULF OF
ALASKA. HOWEVER...THE MAIN ENERGY FROM THE DISTURBANCES ROUNDING THE
TROUGH WILL PUSH INTO NORTHERN CALIFORNIA...LEAVING SOUTHERN
CALIFORNIA WITH MILD WEATHER...INCREASED ONSHORE FLOW....AND
INTERMITTENT CLOUDINESS. MODELS GENERATE SMALL AMOUNTS OF PRECIP
OVER AND WEST OF OUR LOCAL MOUNTAINS ON TUESDAY...FROM THE TAIL END
OF A COLD FRONT...BUT WILL CONTINUE MONITOR FOR BETTER MODEL RUN TO
RUN CONSISTENCY.
&&
.AVIATION...
131800Z...INCREASING CLOUDS AOA 8000 FEET MSL DURING THE DAY.
LOWER CLOUDS AT 2000-3000 FEET MSL WILL FILL THE COASTAL BASIN
THIS EVENING AFTER 01Z WITH ISOLATED -SHRA AFTER 04Z.
&&
.MARINE...
800 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH
SATURDAY. RAPIDLY BUILDING WEST NORTHWEST SWELL ON SUNDAY MAY
CREATE HAZARDOUS SEAS IN THE OUTER WATERS.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...JT
AVIATION/MARINE...TS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1025 PM EST THU JAN 14 2016
.DISCUSSION...
...RISK OF ISOLATED SEVERE STORMS ACROSS EAST CENTRAL FL ON
FRIDAY...
LATEST RAP ANALYSIS SHOWS THE CENTER OF THE H100-H70 HI PRES RIDGE
WELL E OF THE BAHAMA BANK...SFC LOW TRAILING JUST S OF THE LA COAST.
BTWN THE TWO...A TIGHT PGRAD OVER THE ERN GOMEX POISED TO WORK ITS
WAY ACRS THE FL PENINSULA OVERNIGHT UNDER THE INFLUENCE OF A 115KT
H30-H20 JET. EVNG RAOBS SHOW THE DRY H100-H70 LYR THAT WAS EVIDENT
ON THE MRNG RAOBS HAS LARGELY ERODED THOUGH PWAT VALUES STILL
HOVERING ARND 1.0". E/SE WINDS THRU THE H100-H85 LYR VEERING TO S/SW
THRU THE H85-H70 LYR...RESULTING IN 0-3KM HELICITY VALUES BTWN
200-300M2/S2.
WINDS WILL CONTINUE TO INCREASE OUT OF THE SE OVERNIGHT AS THE SFC
LOW MOVES ENE ACROSS THE NE GOMEX TWD THE FL PANHANDLE/BIG BEND. SFC
DEWPOINTS STILL HOLDING IN THE L/M50S N OF I-4...U50S/L60S TO THE S.
THESE WILL INCREASE THRU DAYBREAK AS THE ONSHORE FLOW TAPS A NEARLY
SATURATED H100-H85 AIRMASS OVER THE NRN BAHAMAS. HELICITY VALUES
ALSO EXPECTED TO JUMP H85-H70 WINDS FRESHEN TO 30-40KTS.
THE NOCTURNAL HEATING MIN WILL LIMIT DEEP CONVECTION POTENTIAL THRU
DAYBREAK...H85-H70 LAPSE RATES BTWN 4.0-5.0C/KM AND LOW CAPE FIELDS
WILL NOT HELP EITHER. HOWEVER...GIVEN THE INCREASING LOW LVL
WINDS...STRONG DIVERGENCE ALOFT...AND NMRS VORT LOBES OVER THE ERN
GOMEX...ANY SHRAS THAT DO DVLP OVERNIGHT WILL HAVE THE POTENTIAL TO
GENERATE STRONG WIND GUSTS THRU DAYBREAK. LOWS WILL RANGE FROM THE
UPPER 50S LEESBURG TO DELAND TO THE MID 60S FOR THE TREASURE COAST.
(PREV DISC)
FRIDAY...STRONG 500 MB IMPULSE WILL MOVE EAST ACROSS N FL WITH 130+
UPPER LEVEL JET ACROSS THE NE GULF AS SFC LOW PRESSURE MOVES ENE
FROM N FL TO OFF THE SC COAST THROUGH THE DAY. ALL MODEL SCENARIOS
INDICATE A WINDOW FROM 12Z-15Z IN THE MORNING HOURS WITH FAVORABLE
DEEP LAYER SHEAR AND IMPRESSIVE 0-1KM AND 0-3KM HELICITY VALUES AS
LOW LVL SOUTHERLY JET STRENGTHENS FROM H9-H8 TO 40-50 KNOTS FROM 12Z-
15Z. EXPECT STRONG TO SEVERE CONVECTION FROM 7AM TO 1 PM ACROSS NRN
SECTIONS WITH THE MAIN TRAILING COLD FRONT LIKELY BRINGING STRONGER
CONVECTION TO SRN SECTIONS IN THE AFTERNOON. SPC CONTINUES A
MARGINAL RISK FOR SEVERE WEATHER WITH ISOLATED TORNADO RISK INTO
LATE MORNING TRANSITIONING TO A STRAIGHT LINE DAMAGING WIND RISK
INTO EARLY TO MID AFTERNOON AS PROFILES BECOME SOMEWHAT MORE
UNIDIRECTIONAL AS LOWEST LAYER FLOW SWINGS AROUND TO THE SSW/SW IN
THE AFTERNOON. RAIN CHANCES WILL BE IN THE 80-90 PCT RANGE WITH
SHOWERS AND STORMS MOVING THROUGH THE AREA IN THE MORNING THRU AT
LEAST MID AFTERNOON. GRADIENT WINDS OUTSIDE CONVECTION WILL ALSO BE
ON THE INCREASE WITH BREEZY TO WINDY CONDITIONS DEVELOPING. MODEL
BLEND USED FOR HIGH TEMP GUIDANCE WITH MOST HIGHS IN THE MID TO
UPPER 70S.
&&
.AVIATION...THRU 16/00Z
SFC WINDS: THRU 15/12Z...E/NE 5-9KTS BCMG SE 8-12KTS. BTWN 15/12Z-
15/15Z...BCMG S 16-20KTS WITH SFC G22-28KTS ALL SITES...CHC OF VRBL
SFC G35KTS IN +TSRA. BTWN 15/15Z-15/18Z...BCMG SW 17-21KTS WITH SFC
G25-30KTS...CHC OF VRBL SFC G35KTS IN +TSRA. BTWN 15/18Z-15/21Z...
BCMG W/SW 12-15KTS WITH SFC 18-22KTS...S OF KISM-KDAB CHC OF VRBL
SFC G35KTS IN +TSRA. AFT 15/21Z...BCMG W 7-11KTS.
VSBY/WX/CIGS: THRU 15/06Z...N OF KISM-KTIX CIGS BTWN FL040-060 BCMG
FL030-050...S OF KISM-KTIX CIGS BTWN FL080-100 WITH AREAS BTWN FL040-
060 IN -SHRA. BTWN 15/06Z-15/12Z...N OF KISM-KTIX CIGS BTWN FL020-
030 WITH LCL CIGS BLO FL010...S OF KISM-KTIX CIGS BTWN FL040-060
WITH AREAS BTWN FL020-030 IN SCT MVFR SHRAS. BTWN 15/12Z-15/15Z...
CIGS BTWN FL020-030 WITH AREAS BLO FL010 N OF KISM-KDAB...MVFR SHRAS
BCMG WDSPRD WITH CHC OF +TSRAS. BTWN 15/15Z-15/21Z...CIGS BTWN FL020-
030 WITH AREA BTWN FL010-020...WDSPRD MVFR SHRAS/SCT IFR TSRAS/CHC
LIFR +TSRAS. AFT 15/21Z...S OF KISM-KTIX CIGS BTWN FL020-030 WITH
MVFR SHRAS/SLGT CHC IFR TSRAS...N OF KISM-KTIX CIGS BCMG FL100-120.
&&
.MARINE...
LATEST BUOY/C-MAN OBS INDICATE INCREASING WINDS TO THE SE WITH
SETTLEMENT POINT AND LAKE WORTH UP TO 15KTS. BUOY009 UP TO 20KTS
BTWN 01Z-02Z...BUT THIS MAY BE ENHANCED BY LIGHT SHRAS BRUSHING THE
BREVARD COUNTY COAST...BUOY010 WAS BLO 10KTS DURING THE SAME TIME
FRAME. WINDS FRESHENING OVERNIGHT AS A TIGHT PGRAD OVER THE ERN
GOMEX WORKS ITS WAY ACRS THE FL PENINSULA AND INTO THE W ATLC...
ANTICIPATE A FRESH TO STRONG S/SE BREEZE TO DVLP IN THE PREDAWN HRS.
SEAS NOT EXPECTED TO BCM FULLY DVLPD UNTIL ARND MIDDAY FRI...BUT
STILL EXPECT THEM TO BUILD TO 4-5FT NEARSHORE AND 5-6FT OFFSHORE BY
DAYBREAK.
WINDS ALOFT BCMG QUITE STRONG OVERNIGHT...SCT SHRAS AND ISOLD TSRAS
MOVG N UP THE GULF STREAM WILL HAVE THE POTENTIAL TO MIX THESE WINDS
DOWN TO THE SFC WITH G35KTS PSBL OVER THE LCL ATLC...ESP OVER THE
TREASURE COAST WATERS.
SCA SET TO GO IN EFFECT AT 09Z FRI MRNG.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO 4 AM EST SATURDAY FOR
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 0-20 NM-
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-
SEBASTIAN INLET TO JUPITER INLET 0-20 NM-SEBASTIAN INLET TO
JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
849 PM EST THU JAN 14 2016
...DANGEROUS MARINE CONDITIONS WITH ADVISORY TO GALE FORCE
WINDS...AND HIGH WAVES EXPECTED OVER THE WATERS LATE TONIGHT
THROUGH FRIDAY...
...ISOLATED STRONG/SEVERE STORMS EXPECTED EARLY FRIDAY MORNING
THROUGH FRIDAY AFTERNOON...
...MINOR COASTAL FLOODING LIKELY ALONG PORTIONS OF THE NATURE
COAST LATE TONIGHT INTO FRIDAY...
.UPDATE (REST OF TONIGHT)...
01Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE WEATHER SYSTEM
EXPECTED TO IMPACT THE FLORIDA PENINSULA DURING FRIDAY BEGINNING
TO TAKE SHAPE OVER THE WESTERN/NORTH-CENTRAL GULF OF MEXICO. A
SERIES OF MID-LEVEL IMPULSES ARE NOW STREAMING OFF THE UPPER TEXAS
COAST...WITH THE MOST ORGANIZED ENERGY LOCATED AROUND THE H4
HEIGHT. UNDER/AHEAD OF THIS ENERGY...THE FIRST SIGNS OF A SURFACE
REFLECTION LOW CAN BE ANALYZED SOUTH OF THE LOUISIANA COAST.
CLOSER TO HOME...THE RIDGE OF SURFACE HIGH PRESSURE THAT HAS
PROVIDED GENERALLY FAIR WEATHER TO THE FORECAST AREA THE PAST
COUPLE OF DAYS IS NOW STEADILY SHIFTING EASTWARD AND GIVING UP
INFLUENCE ON OUR WEATHER. THE OVERNIGHT PERIOD WILL BE THE
TRANSITION ACROSS THE PENINSULA FROM THIS RIDGE...TO THE APPROACH
OF THE ORGANIZING LOW OVER THE NORTHERN GULF. DURING THE PRE-DAWN
HOURS...CONVECTION IS PROGGED TO ORGANIZE AHEAD OF A COLD FRONT
SURGING ACROSS THE GULF OF MEXICO TO THE SOUTH OF THE LOW TRACK.
IT IS LIKELY THAT THIS CONVECTION WILL BE THREATENING OUR MARINE
ZONES BY THE TIME THE SUN RISES. SOME OF THE STORMS AHEAD OF THIS
FRONT ARE LIKELY TO BE STRONG OVER THE EASTERN GULF...ADDING TO
THE ALREADY HAZARDOUS CONDITIONS PRESENT FROM THE GRADIENT WINDS.
LOOKING AT THE LATEST HIRES CONVECTION ALLOWING GUIDANCE...IT IS
LIKELY THAT ANY SIGNIFICANT THUNDERSTORM ACTIVITY WILL HOLD OFF
OVER THE LAND ZONES UNTIL AT LEAST SUNRISE. HOWEVER...SCT SHOWERS
MOVING INLAND OFF THE GULF WILL BECOME MORE AND MORE LIKELY THE
FURTHER INTO THE OVERNIGHT WE GET.
THE CLOUD COVER AND INCREASING LOW LEVEL MOISTURE AHEAD OF THE
DEVELOPING STORM SYSTEM WILL KEEP TEMPERATURES MUCH WARMER THAN
PREVIOUS NIGHTS. LOW TEMPERATURES IN THE PRE-DAWN HOURS SHOULD
RANGE FROM THE MID/UPPER 50S TO THE NORTH OF BROOKSVILLE...TO THE
LOWER 60S ALONG THE I-4 CORRIDOR...AND LOWER TO MIDDLE 60S OVER
THE FAR SOUTHERN ZONES DOWN AROUND FORT MYERS. WINDS WILL BE
SLOWLY RAMPING UP AFTER MIDNIGHT AS WELL...ESPECIALLY ALONG THE
IMMEDIATE COAST. CONDITIONS SHOULD BE NOTICEABLY MORE BREEZY NEAR
THE COAST BY THE TIME THE SUN RISES THAN THEY ARE LATE THIS
EVENING.
FOR DETAILED INFORMATION ON THE THREAT OF ISOLATED SEVERE STORMS
ALONG AND SOUTH OF THE I-4 CORRIDOR DURING FRIDAY...AND OTHER
ASPECTS OF THE PASSING STORM...PLEASE SEE THE PREVIOUS DISCUSSION
FROM THE AFD WRITTEN THIS PAST AFTERNOON.
&&
.PREVIOUS DISCUSSION (FRIDAY)...
AS HEIGHT FALLS OVERSPREAD THE MOIST AND UNSEASONABLY WARM GULF
WATERS...EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO INCREASE
MARKEDLY OVER THE GULF WATERS IN THE WEE MORNING HOURS FRIDAY.
WITH A STRONG UPPER JET IN PLACE...WIND PROFILES WILL FAVOR
ROTATING THUNDERSTORMS...AND EXPECT SUPERCELLULAR DEVELOPMENT OVER
THE WATERS...WHERE SUFFICIENT INSTABILITY WILL EXIST. AS THESE
STORMS GRADUALLY SHIFT EASTWARD THROUGH SUNRISE...THEY WILL BEGIN
TO APPROACH THE COOLER SHELF WATERS OF THE GULF...WHERE STABILITY
WILL BE VERY LIMITED. THIS SHOULD GENERALLY RESULT IN A WEAKENING
OF STRONGER THUNDERSTORMS...AND A DECREASED SEVERE RISK.
INITIALLY...THE MAIN CONCERN WILL BE STRONG SOUTH/SOUTHEAST WINDS
AND HIGH WAVES OVER THE MARINE ZONES...REQUIRING UPGRADE TO GALE
WARNING AND SMALL CRAFT ADVISORY. IN ADDITION...THE ONSHORE WINDS
IN CONJUNCTION WITH TIDAL FLUCTUATIONS WILL ALLOW FOR MINOR
COASTAL FLOODING OVER COASTAL PORTIONS OF LEVY AND CITRUS
COUNTIES.
FROM SUNRISE THROUGH EARLY AFTERNOON...THE SYSTEM IS EXPECTED TO
ACCELERATE NORTHEASTWARD...DRIVING A COLD FRONT ACROSS THE FLORIDA
PENINSULA. THIS WILL BRING SHOWERS AND STORMS FROM THE EASTERN
GULF INLAND. WHILE INSTABILITY WILL GENERALLY REMAIN FAIRLY
WEAK...SUFFICIENT DESTABILIZATION MIGHT HAVE OCCURRED FOR THE
OCCURRENCE OF STRONG/DAMAGING WIND GUSTS...AND A TORNADO OR TWO
WITH THE FEW STORMS THAT CAN MANAGE OVER THE COOLER NEARSHORE
WATERS. SHOULD DAMAGING WINDS OR A TORNADO OCCUR...THE MOST
LIKELY TIMING APPEARS TO BE FROM AROUND 7 AM THROUGH 1 PM...AND
PRIMARILY FOR AREAS ALONG AND SOUTH OF I-4. IN ADDITION...HEAVY
RAINFALL MAY OCCUR ALONG PORTIONS OF THE NATURE COAST AND NORTHERN
FLORIDA...NEARER THE WARM FRONT AND STRONGER UPPER LEVEL ENERGY.
BY FRIDAY AFTERNOON...THE STORM SYSTEM WILL SHIFT EAST INTO THE
ATLANTIC. THIS WILL BRING A FAST MOVING FRONT THROUGH THE
STATE...WITH BREEZY AND DRY CONDITIONS BY EARLY FRIDAY EVENING.
&&
.AVIATION...
GENERAL VFR CONDITIONS WILL PERSIST INTO THE PRE-DAWN
HOURS...ALTHOUGH EXPECT SCT LIGHT SHOWERS TO BEGIN IMPACTING
THE TERMINALS AFTER MIDNIGHT. FROM DAWN THROUGH THE EARLY
AFTERNOON FRIDAY WILL BE WHEN THE POTENTIAL FOR MORE ORGANIZED
SHOWER/THUNDERSTORM WILL BE CROSSING THE AREA. ISOLATED STORMS MAY
BE STRONG TO SEVERE. EXPECT A MIX OF MVFR/VFR CONDITIONS WITH
BRIEF IFR POSSIBLE ASSOCIATED WITH HEAVY THUNDERSTORM RAINFALL.
RAINFALL TAPERS OFF FROM WEST TO EAST IN THE AFTERNOON. EXPECT
WINDY CONDITIONS FROM THE SOUTH FRIDAY...SHIFTING WEST IN PM.
&&
.MARINE...
DANGEROUS MARINE CONDITIONS ARE EXPECTED BEGINNING LATE TONIGHT
AND CONTINUING INTO FRIDAY AFTERNOON AS LOW PRESSURE AND ITS
ASSOCIATED COLD FRONT TRACK ACROSS THE CENTRAL AND EASTERN GULF OF
MEXICO. ADVISORY LEVEL WINDS WILL QUICKLY RAMP UP AROUND
MIDNIGHT...WITH GALE FORCED WINDS...ESPECIALLY IN GUSTS...
OVERSPREADING THE NORTHERN WATERS LATE TONIGHT INTO FRIDAY
MORNING. IN ADVANCE OF THE COLD FRONT...WIDESPREAD SHOWERS AND
STORMS ARE EXPECTED BY LATER TONIGHT INTO FRIDAY MORNING. SOME OF
THE STORMS WILL BE STRONG TO SEVERE IN THE MORNING HOURS. WINDS
WILL SHIFT TO THE WEST FRIDAY AFTERNOON AS THE FRONT SHIFTS EAST
OF THE FORECAST WATERS. THE GRADIENT WILL WEAKEN...ALLOWING WINDS
TO GRADUALLY DIMINISH BY LATE FRIDAY AFTERNOON/EVENING...HOWEVER
RESIDUAL WAVES MAY TAKE LONGER TO SUBSIDE. WINDS LOOK TO REMAIN
BELOW HEADLINE CRITERIA SATURDAY...BUT INCREASE AGAIN LATE
SATURDAY NIGHT INTO SUNDAY AS ANOTHER QUICK MOVING STORM SYSTEM
MOVES ACROSS THE GULF OF MEXICO. STRONG HIGH PRESSURE LOOKS TO
BUILD INTO THE REGION EARLY NEXT WEEK...WITH PERSISTING
NORTH/NORTHEAST WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 63 73 61 74 / 60 100 10 10
FMY 64 77 62 79 / 60 100 10 10
GIF 61 76 58 77 / 50 100 10 10
SRQ 63 74 62 75 / 60 100 10 10
BKV 59 75 53 76 / 50 100 10 10
SPG 63 74 63 75 / 60 100 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM EST
FRIDAY FOR COASTAL CITRUS-COASTAL LEVY.
GULF WATERS...SMALL CRAFT ADVISORY FROM 1 PM TO 7 PM EST FRIDAY FOR
COASTAL WATERS FROM TARPON SPRINGS TO SUWANNEE RIVER
FL OUT 20 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.
GALE WARNING FROM MIDNIGHT TONIGHT TO 1 PM EST FRIDAY FOR
COASTAL WATERS FROM TARPON SPRINGS TO SUWANNEE RIVER
FL OUT 20 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 FROM MIDNIGHT TONIGHT TO 7 PM EST
FRIDAY FOR COASTAL WATERS FROM BONITA BEACH TO
ENGLEWOOD FL OUT 20 NM-COASTAL WATERS FROM ENGLEWOOD
TO TARPON SPRINGS FL OUT 20 NM-WATERS FROM BONITA
BEACH TO ENGLEWOOD FL OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST
FRIDAY FOR CHARLOTTE HARBOR AND PINE ISLAND SOUND-
TAMPA BAY WATERS.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
PREVIOUS DISCUSSION...AUSTIN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
923 PM CST THU JAN 14 2016
.UPDATE...
828 PM CST
AFTER COLLABORATION WITH NEIGHBORING OFFICES... WE ARE BACKING
OFF ON CHANCES FOR PRECIPITATION DURING THE OVERNIGHT HOURS. 0Z
RAOBS AND OBSERVATIONS STILL DEPICTING FAIRLY DRY CONDITIONS
ACROSS THE WARM SECTOR OF THE LOW THIS EVENING...WHICH COVERS MOST
OF THE FORECAST AREA. DEWPOINT DEPRESSIONS CONTINUE TO LOWER AS
MOISTURE ADVECTION/TRANSPORT INCREASES FROM THE SOUTHWEST WHERE
UPSTREAM DEWPOINTS ARE IN THE UPPER 30S TO LOW 40S. BECAUSE THIS
...HI-RES GUIDANCE DEPICTING A DELAY IN LOWER LEVEL SATURATION
UNTIL LATE TONIGHT OR EARLY FRIDAY. WITH THIS CONTINUED MOISTURE
ADVECTION GUIDANCE IS STILL SUGGESTING A LOWER STRATUS WILL FORM
AS THESE HIGHER DEWPOINTS ENCOUNTER A RELATIVELY COLD
AIRMASS....BUT NOT FOR A WHILE. WITH SOME OMEGA IN THIS LOW LEVEL
FIELD...THERE STILL EXISTS A CHANCE FOR SOME DRIZZLE TOMORROW
MORNING IN NE ILLINOIS...WITH A BETTER CHANCE FOR ACTUAL RAINFALL
CONFINED ALONG AND EAST OF I-55/I-57. WORKING ON NEW GRIDS AND
SHOULD HAVE THEM AVAILABLE SHORTLY.
MEANWHILE...ALOLNG THE WISCONSIN BORDER WHERE LESS SNOWMELT
OCCURRED AND CLEAR SKIES AND LIGHTER WINDS ARE OCCURING...SOME FOG
HAS FORMED...NAMELY NEAR WAUKEGAN. IT IS POSSIBLE IN AREAS THAT
THIS COULD EXPAND SOME ...BUT WINDS SHOULD REMAIN UP IN MANY
PLACES AS THE CORE OF THE LOW PASSES TO OUR NORTH.
KMD
&&
.SHORT TERM...
225 PM CST
THROUGH FRIDAY...
STARK CONTRAST THIS AFTERNOON FROM THE PAST FEW DAYS...AS THE REGION
SEES A BRIEF LULL IN THE DEEP FREEZE WITH A MID-JANUARY THAW. THE
THERMAL TROUGH HAS RETREATED NORTH ALLOWING MUCH WARMER AIR TO
ADVECT IN ON THE NOSE OF A STRENGTHENING LOW LEVEL JET AT 850MB. THE
RISE IN HEIGHTS ALOFT HAS ALLOWED AN EROSION OF THE LOW/MID LEVEL
CLOUDS...WHICH COUPLED WITH THE WARM AIR ADVECTION HAS ALLOWED SFC
TEMPS TO PUSH INTO THE LOW/MID 40S IN MANY AREAS AND QUICKLY MELTING
THE SNOWPACK. VISIBLE SATELLITE IMAGERY THIS AFTERNOON SHOWS THE
RECEEDING SNOWPACK QUITE WELL. ALONG THE SOUTHERN TIER OF
COUNTIES...MAINLY SOUTH OF I-80...THE SNOWPACK WAS LESS TO BEGIN
WITH...WHICH HAS ALLOWED SFC TEMPS TO RISE NEAR 50 DEGREES.
LATER TONIGHT THE LOW LEVEL JET IS PROGGED TO CONTINUE TO INCREASE
AS IT LIFTS NORTH ACROSS CENTRAL IL TOWARDS NORTHERN IL...WITH
GUIDANCE INDICATING SPEEDS AT 2-3KFT AGL HOVERING AROUND 40-50KT
OVERNIGHT. UPSTREAM ACROSS SOUTHERN IOWA/NORTHERN MISSOURI IS A WEAK
MID-LVL FEATURE THAT HAS SOME MID/HIGH DECK CLOUDS SLIDING
EAST...AND IS PROGGED TO ARRIVE LATER TONIGHT ACROSS THE FORECAST
AREA. LOW LEVEL MOISTURE TONIGHT WILL MAKE THE OVERNIGHT FORECAST
TRICKY...WITH THE POTENTIAL FOR PATCHY FOG TO DEVELOP AND LOW
CLOUDS. SEVERAL GUIDANCE MEMBERS ARE TRYING TO SLIDE A CHANNEL OF
INCREASED MOISTURE NORTHEAST ACROSS THE MID-MISSOURI VALLEY TOWARDS
NORTHERN IL...THIS IS MATCHED UP WITH THE STRENGTHENING MID-LVL
TROUGH AXIS THAT WILL BE PIVOTING INTO THE SOUTHERN PLAINS AROUND 9Z
FRI. HAVE HELD ONTO THE MENTION OF PATCHY FOG...HOWEVER CONFIDENCE
IN THIS DEVELOPING WILL REMAIN LOW AS IT APPEARS ENOUGH OF A T/TD
SPREAD WILL REMAIN. GUIDANCE HAS PUSHED BACK THE TIMING OF PRECIP
UNTIL CLOSER TO 9Z...BUT HAVE A STEADY INCREASE IN POPS BY DAYBREAK
FRI. TEMPS OVERNIGHT WILL REMAIN MILD...AND MAY NOT DIP MUCH AT ALL
WITH LOWS GENERALLY IN THE MID/UPR 30S TO AROUND 40 IN THE FAR
SOUTHERN CWFA.
FRIDAY... THE MID-LVL TROUGH WILL BE STEADILY DEEPENING AND
PUSHING EAST ACROSS IOWA/MISSOURI...ALLOWING THE LLVL MOISTURE
CHANNEL TO LIFT OVER NORTHERN IL/NORTHWEST IN. GUIDANCE HAS BEEN
STRUGGLING WITH HOW WIDESPREAD AND INTENSE PRECIP WILL END UP
BEING THROUGH MIDDAY...BUT THERE IS SOME CONSISTENCY WITH A BETTER
CHANCE FOR POPS IN THE EASTERN CWFA BY THE AFTERNOON HOURS AS
THE FRONTAL BOUNDARY STEADILY PUSHES EAST. THERE HAS BEEN SOME
SLOWING IN THE WARM LAYER DEPARTING TO THE EAST DURING THE
DAY...SO HAVE HELD ONTO THE WARMER TEMPS A LITTLE LONGER WHICH
WILL SLOW THE TRANSITION OVER FROM RAIN TO SNOW UNTIL MID/LATE
AFTN. THE PRESSURE GRADIENT WILL STEADILY TIGHTEN...WITH BREEZY
COLDER AIR STEADILY ADVECTING IN FROM THE WEST/NORTHWEST. EXPECT
STEADILY FALLING TEMPS BY MID/LATE FRI AFTN INTO THE LOW/MID
30S...WITH PRECIP QUICKLY TRANSITIONING BACK TO LIGHT SNOW. AT
THIS TIME IT DOES NOT APPEAR ANY ACCUMS WILL OCCUR.
BEACHLER
&&
.LONG TERM...
245 PM CST
FRIDAY NIGHT THROUGH THURSDAY...
THE CONCERN FOR THE EXTENDED FORECAST PERIOD WILL BE AN INTRUSION OF
ARCTIC AIR INTO THE REGION.
BY FRIDAY EVENING...THE SYSTEM RESPONSIBLE FOR FRIDAY`S PCPN WILL BE
LIFTING NEWD THROUGH THE ERN GREAT LAKES WHILE ARCTIC HIGH PRESSURE
BEGINS TO NOSE INTO THE NRN PLAINS. THE COMBINATION OF THE OLD NRN
STREAM LOW AND A SRN STREAM LOW OFF THE MID ATLANTIC COAST WITH
ANOTHER WEAK LOW DEVELOPING OVER WEST TEXAS WILL HELP FOCUS THE
ARCTIC HIGH TO PUSH SOUTH THROUGH THE CENTRAL PLAINS. COLD
ADVECTION SHOULD BEGIN THROUGH THE DAY ON SATURDAY SO THERE SHOULD
BBE LITTLE DIURNAL VARIATION IN TEMPERATURES FROM THE RELATIVELY
MILD CONDITIONS FRIDAY NIGHT UNTIL AROUND MIDDAY SATURDAY. THE MUCH
COLDER AIR SHOULD BEGIN TO PUSH INTO THE REGION SATURDAY
AFTERNOON...WITH TEMPERATURES DROPPING INTO THE SINGLE DIGITS AROUND
THE ROCKFORD AREA BY LATE AFTERNOON OR EARLY EVENING. THE POSITION
OF THE SFC HIGH OVER THE PLAINS AND RELATIVELY LOW PRESSURE OVER THE
EAST COAST WILL VARY LITTLE THROUGH THE REMAINDER OF THE WEEKEND AND
INTO EARLY NEXT WEEK...SO THE FETCH OF ARCTIC AIR WILL GO UNABATED.
WHILE A WEAK NRN STREAM SHORTWAVE SKIRTING ON THE SRN EDGE OF THE
ARCTIC HIGH MAY BRING A BRIEF PERIOD OF DENSE CLOUD COVER AND SOME
LIGHT SNOW...THERE SHOULD BE LITTLE IMPACT ON THE EXPECTED
TEMPERATURE TREND. TEMPERATURES SHOULD DROP BELOW 0F EARLY SUNDAY
MORNING OVER PORTIONS OF THE AREA NORTH OF I80 AND WEST OF THE FOX
VALLEY. SUB-ZERO MIN TEMPS ARE LIKELY FOR THE ENTIRE CWA BY MONDAY
MORNING...WITH THE EXCEPTION OF THE IMMEDIATE LAKEFRONT AND DOWNTOWN
CHICAGO. THE CORRIDOR FROM MCHENRY THROUGH DEKALB TO ROCHELLE
SEEING THE LOWEST TEMPERATURES OF THE PERIOD...WITH MINS OF
-8F TO -10F. WIND CHILLS WILL BE DANGEROUSLY LOW THROUGH THIS
PERIOD AS WELL WITH A PERSISTENT MODERATE NWLY PRESSURE GRADIENT
KEEPING 5 TO 10 MPH WINDS OVER THE AREA. WIND CHILL READINGS WILL
DROP BELOW -20F FOR MUCH OR ALL OF THE CWA SUNDAY AND MONDAY MORNING
AND WIND CHILL ADVISORIES WILL LIKELY BE ISSUED. HIGHS ON SUNDAY
AND MONDAY SHOULD REMAIN IN THE SINGLE DIGITS ABOVE ZERO FOR ALL BUT
THE FAR SERN PORTIONS OF THE CWA...WHICH SHOULD TOP OUT AT 11-12F.
BY TUESDAY MORNING...TEMPERATURES WILL STILL STILL RANGE FROM
THESINGLE DIGITS BELOW ZERO TO THE SINGLE DIGITS ABOVE ZERO...BUT
WIND CHILL READINGS SHOULD NOT BE QUITE AS LOW AS THE HIGH PRESSURE
SPREADS OVER THE LOCAL AREA AND INTO THE UPPER OHIO VALLEY...
ALLOWING WINDS TO DIMINISH. HIGH PRESSURE WILL LINGER OVER THE
REGION INTO MIDWEEK...THOUGH AMPLE SUNSHINE AND A SHUTTING DOWN OF
THE COLD ADVECTION SHOULD ALLOW TEMPERATURES TO MODERATE BY MIDWEEK
WITH TEMPERATURES REBOUNDING TO NEAR SEASONAL NORMAL LEVELS.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LOWERING CIG/VSBY TRENDS OVERNIGHT AND FRIDAY MORNING.
* PRECIP CHANCES AND TIMING OVERNIGHT AND FRIDAY MORNING.
* LLWS LIKELY OVERNIGHT INTO MORNING.
LENNING
//DISCUSSION...UPDATED 00Z...
DESPITE WIDE DISAGREEMENT AMOUNG VARIOUS FORECAST MODELS...AND
LITTLE IN THE WAY OF EXISTING MVFR OR IFR OBSERVATIONS UPSTREAM
FROM THE AREA...A TREND TOWARD LOWER CONDITIONS AND LIGHT PRECIP
DOES APPEAR LIKELY BY MORNING. AM JUST NOT SURE HOW LOW. EVEN
SO...THE 00Z TAFS START THE LOWER CONDITIONS A BIT LATER THAN
PREVIOUS FORECASTS...BUT THE TIMING OF THE LOWEST CONDITIONS
TOMORROW MORNING STILL APPEARS TO BE ON TARGET.
MOTIVATION FOR THE SLOWER START COMES FROM A SOMEWHAT WARMER AND
DRIER BOUNDARY LAYER THAN WHAT SOME MODELS ARE SHOWING...AS
SUPPORTED BY THE LATEST AMDAR SOUNDINGS LOCALLY AND THE COMPLETE
LACK OF LOWER CEILINGS ANYWHERE IMMEDIATELY UPSTREAM ACROSS
IOWA...ILLINOIS...AND MISSOURI.
GIVEN THE APPROACH OF A LOW PRESSURE CENTER TO OUR NORTHWEST AND
A COLD FRONT TO OUR WEST...THE SOURCE REGION FOR OUR LOW LEVEL
AIRMASS OVERNIGHT AND IN THE MORNING APPEARS TO BE EASTERN OK AND
WESTERN AR WHERE A FEW SITES ARE REPORTING SCT-BKN 040-055. THE
NAM AND RAP SUGGEST THE RELATIVELY MOIST AIRMASS FROM THIS REGION
MIGHT MIX INTO THE THE LOCALLY COLDER AIR SOMEWHERE IN THE 08Z
TIMEFRAME...AFTER WHICH LOWER LEVEL SATURATION AND SOME LIGHT RAIN
OR DRIZZLE WOULD BE EXPECTED TO DEVELOP FAIRLY QUICKLY.
AS THE FRONT MOVES THROUGH THE AREA DURING THE LATE MORNING AND
WINDS TURN WESTERLY...LOW CLOUDS MAY HANG AROUND THROUGH THE REST
OF THE DAY BUT THE RA/DZ SHOULD COME TO AN END.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* LOW TO MEDIUM FOR CIGS/VSBYS OVERNIGHT AND FRIDAY MORNING.
* MEDIUM FOR CIGS AND MEDIUM HIGH FOR VSBYS FRIDAY AFTERNOON.
* MEDIUM FOR WINDS...AND MEDIUM TO HIGH FOR LLWS TONIGHT.
LENNING
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY AND SUNDAY...DRY. MVFR POSSIBLE. GUSTY NORTHWEST WINDS.
VERY COLD SUNDAY.
* MONDAY AND TUESDAY...DRY/VFR. WESTERLY WINDS. VERY COLD MONDAY.
* WEDNESDAY...CHANCE OF SNOW SHOWERS. MVFR POSSIBLE. WEST WINDS.
LENNING
&&
.MARINE...
323 PM CST
A VERY ACTIVE PATTERN IS SETTING UP FOR LAKE MICHIGAN FOR THE NEXT
SEVERAL DAYS.
A WARM FRONT EXTENDS FROM LOW PRESSURE OVER SRN MINNESOTA EAST
ACROSS CENTRAL LAKE MICHIGAN. GUSTY SOUTH WINDS TO ARND 25KT WILL
PERSIST INTO THE EVENING OVER THE SOUTHERN END OF THE LAKE WHILE
WINDS WILL START OUT SELY OVER THE NORTHERN PORTIONS OF THE LAKE.
THE LOW IS EXPECTED TO TRACK ACROSS THE CENTER OF THE LAKE
FRIDAY...WITH THE SLY WINDS OVER THE SRN HALF OF THE LAKE INCREASING
TO ARND 30KT...WHILE WINDS OVER THE NORTH END OF THE LAKE STRENGTHEN
TO ARND 30KT AND BECOME ELY. AS THE LOW PASSES OFF TO THE EAST
FRIDAY NIGHT...STRONG ARCTIC HIGH PRESSURE WILL BUILD INTO THE
CENTRAL PLAINS...SETTING UP AN EXTENDED PERIOD OF STRONG NWLY WINDS
BRINGING MUCH COLDER AIR ACROSS THE LAKE. THE VERY COLD AIR WILL
BEGIN TO OVERSPREAD THE LAKE SATURDAY NIGHT WITH THE COLD AIR
EXPECTED TO PERSIST INTO EARLY NEXT WEEK. A BRIEF PERIOD OF NWLY
GALES ARE POSSIBLE FOR FRIDAY NIGHT WITH A STRONG NWLY GRADIENT
DEVELOPING BETWEEN THE EXITING LOW AND THE HIGH BUILDING INTO THE
CENTRAL PLAINS. THE WINDOW OF OPPORTUNITY FOR GALES FRIDAY NIGHT
SHOULD BE RELATIVELY SHORT AS THE LOW QUICKLY LIFTS INTO QUEBEC AND
THE GRADIENT OVER THE LAKE RELAXES. THE NWLY GRADIENT SHOULD
STRENGTHEN AGAIN LATE SATURDAY NIGHT AND SUNDAY AS A MID LEVEL
IMPULSE TRACKS THROUGH THE UPPER GREAT LAKES AND THE SURGE OF VERY
COLD AIR OVERSPREADS THE LAKE. THE COMBINATION OF STRONG
WINDS...POSSIBLY REACHING GALE FORCE SUNDAY AFTERNOON AND
EVENING...AND VERY COLD AIR WILL COMBINE TO BRING A PERIOD OF
MODERATE FREEZING SPRAY TO THE ENTIRE LAKE...FROM SATURDAY NIGHT
THROUGH MONDAY. BY MONDAY NIGHT...THE ARCTIC HIGH WILL BEGIN TO
OVERSPREAD THE LAKE ALLOWING WINDS TO DIMINISH AND END THE THREAT OF
FREEZING SPRAY. RELATIVELY LIGHT WLY WINDS ARE EXPECTED BY
WEDNESDAY AS THE CENTER OF THE HIGH PRESSURE SLIDES SOUTH OF THE
LAKE WHILE WEAK LOW PRESSURE BEGINS TO DEVELOP OVER THE WESTERN
PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...3 PM FRIDAY TO 3
PM SATURDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 PM FRIDAY TO 9
PM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
906 PM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 900 PM CST THU JAN 14 2016
The 00z KILX sounding indicated very dry air in place across
central Illinois this evening. Even an upstream 00z sounding at
KSGF, Springfield Missouri, showed similarly dry conditions. The
HRRR and RAP models have been progressively slowing down the onset
of any precipitation across central Illinois, as have the NAM12
and namdng but to a lesser extent. Satellite loops are showing the
upstream shortwave in eastern Texas and Arkansas may take a track
that would focus our forcing for precip later tonight and Friday
to areas east of I-55. The passage of the cold front in
conjunction with the arrival of upper level energy will put the
better chances of rain mainly from mid morning into early
afternoon, before the front departs into Indiana.
Have updated the PoP and weather grids to slow down the onset of
rain overnight, with only slight chances of precip before 12z.
Also reduced the areal coverage of likely PoPs Friday morning
closer to the I-57 corridor and areas east of there.
The arrival of colder air will be late enough in the event to
limit the potential of accumulating snowfall, and mainly north of
I-74.
Temperatures overnight will likely remain much above normal under
the continued mild southwest flow. A few strong wind gusts could
continue to show up as well, with a 50kt LLJ just above the
ground, and marginal decoupling of the boundary layer this
evening.
Updated forecast info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 322 PM CST THU JAN 14 2016
20z/2pm surface analysis shows 1022mb high anchored over Georgia,
while a 997mb low organizes over eastern South Dakota. The pressure
gradient between these two features will continue to provide a
warm/southerly flow across central Illinois tonight, which will keep
temperatures several degrees warmer than in previous nights. Thanks
to southerly winds of 10 to 15mph through the night and increasing
clouds, overnight low temperatures will remain in the upper 30s and
lower 40s. As the South Dakota low tracks eastward into Wisconsin,
it will pull a cold front toward the region later tonight.
Increasing low-level moisture along/ahead of the boundary will
eventually yield a few light rain showers after midnight. HRRR
suggests the precip will develop along/west of a Champaign to
Taylorville line between 06z and 09z...then will spread further
eastward across the remainder of the area toward dawn. Since
forecast soundings do not fully saturate through a deep layer...will
maintain just chance PoPs overnight until deeper moisture arrives
Friday morning.
.LONG TERM...(Friday through Thursday)
ISSUED AT 322 PM CST THU JAN 14 2016
Models in good agreement with the system that will be moving through
the CWA Friday, as the low pressure area moves across the Great
Lakes with the trailing cold front sliding across the state during
the morning. Once this occurs, much colder air will pour into the
area with temperatures falling during the afternoon hours. During
the day, all the pcpn will be liquid, but when the temps begin to
fall the pcpn will become mixed with snow as it is ending. Do not
see any accumulation of snowfall with this system. Then, after a
brief period of dry weather thru Saturday evening, a clipper system
will move toward the area and bring snow to the area beginning late
Sat night and continuing through Sunday morning. By Sun afternoon,
the snow will have ended and moved east of the area.
Temps will be warm one more day, tomorrow, but then fall beginning
in the afternoon. So, look for morning or late morning highs. Temps
will continue to fall during the night, and then go back up on Sat,
but remain below normal. Then much colder air will pour into the
area for the weekend, with temps below zero in the north Sat night.
Below zero temps are expected again Sun night, but over most of the
area...with only southeast IL seeing above zero temps...though in
the single digits.
Next chance of pcpn will be another clipper system coming toward the
area, but tracking mostly south of the CWA for Tue into Tue night.
Will have a chance of snow in the southwest third of the area for
Tue and then a slight chance of snow over the whole area for Tue
night. Then toward the later half of the week, another weather
system will move toward the area. Models show much disagreement with
this system at this point, so will just go with the blend for now
and have a slight chance of pcpn for Wed night and then a chance
across the southern half of the CWA for Thur. P-type will be mainly
snow in the north, but a mix of rain and snow in the south.
Temps will start cold, but gradually warm back toward normal for Wed
and Thur.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 600 PM CST THU JAN 14 2016
VFR conditions will prevail through the evening before low-level
moisture increases ahead of an approaching cold front later
tonight. NAM12, HRRR, and namdng consensus still pointing toward
MVFR clouds and spotty showers developing over central IL between
08z and 12z, including our TAF sites. Profiles never become
saturated through a deep layer, so will only mention VCSH with the
front. The HRRR and NAM/GFS forecast soundings support IFR clouds
just behind the front for a couple hours. Therefore, have
introduced IFR cloud heights at all terminal sites for the mid
morning time frame. Once the boundary pushes east, gusty
southerly winds will veer to the west Friday morning. FROPA
timing appears to be about 16z at KPIA and closer to 18z at KCMI.
While sustained surface winds will remain quite brisk at around
14-15kt tonight, radar VWP plots and the NAM are showing a strong
45-50kt 925mb jet developing. Have therefore continued to include low-
level wind shear at the TAF sites tonight.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
845 PM CST THU JAN 14 2016
.UPDATE...
828 PM CST
AFTER COLLABORATION WITH NEIGHBORING OFFICES... WE ARE BACKING
OFF ON CHANCES FOR PRECIPITATION DURING THE OVERNIGHT HOURS. 0Z
RAOBS AND OBSERVATIONS STILL DEPICTING FAIRLY DRY CONDITIONS
ACROSS THE WARM SECTOR OF THE LOW THIS EVENING...WHICH COVERS MOST
OF THE FORECAST AREA. DEWPOINT DEPRESSIONS CONTINUE TO LOWER AS
MOISTURE ADVECTION/TRANSPORT INCREASES FROM THE SOUTHWEST WHERE
UPSTREAM DEWPOINTS ARE IN THE UPPER 30S TO LOW 40S. BECAUSE THIS
...HI-RES GUIDANCE DEPICTING A DELAY IN LOWER LEVEL SATURATION
UNTIL LATE TONIGHT OR EARLY FRIDAY. WITH THIS CONTINUED MOISTURE
ADVECTION GUIDANCE IS STILL SUGGESTING A LOWER STRATUS WILL FORM
AS THESE HIGHER DEWPOINTS ENCOUNTER A RELATIVELY COLD
AIRMASS....BUT NOT FOR A WHILE. WITH SOME OMEGA IN THIS LOW LEVEL
FIELD...THERE STILL EXISTS A CHANCE FOR SOME DRIZZLE TOMORROW
MORNING IN NE ILLINOIS...WITH A BETTER CHANCE FOR ACTUAL RAINFALL
CONFINED ALONG AND EAST OF I-55/I-57. WORKING ON NEW GRIDS AND
SHOULD HAVE THEM AVAILABLE SHORTLY.
MEANWHILE...ALOLNG THE WISCONSIN BORDER WHERE LESS SNOWMELT
OCCURRED AND CLEAR SKIES AND LIGHTER WINDS ARE OCCURING...SOME FOG
HAS FORMED...NAMELY NEAR WAUKEGAN. IT IS POSSIBLE IN AREAS THAT
THIS COULD EXPAND SOME ...BUT WINDS SHOULD REMAIN UP IN MANY
PLACES AS THE CORE OF THE LOW PASSES TO OUR NORTH.
KMD
&&
.SHORT TERM...
225 PM CST
THROUGH FRIDAY...
STARK CONTRAST THIS AFTERNOON FROM THE PAST FEW DAYS...AS THE REGION
SEES A BRIEF LULL IN THE DEEP FREEZE WITH A MID-JANUARY THAW. THE
THERMAL TROUGH HAS RETREATED NORTH ALLOWING MUCH WARMER AIR TO
ADVECT IN ON THE NOSE OF A STRENGTHENING LOW LEVEL JET AT 850MB. THE
RISE IN HEIGHTS ALOFT HAS ALLOWED AN EROSION OF THE LOW/MID LEVEL
CLOUDS...WHICH COUPLED WITH THE WARM AIR ADVECTION HAS ALLOWED SFC
TEMPS TO PUSH INTO THE LOW/MID 40S IN MANY AREAS AND QUICKLY MELTING
THE SNOWPACK. VISIBLE SATELLITE IMAGERY THIS AFTERNOON SHOWS THE
RECEEDING SNOWPACK QUITE WELL. ALONG THE SOUTHERN TIER OF
COUNTIES...MAINLY SOUTH OF I-80...THE SNOWPACK WAS LESS TO BEGIN
WITH...WHICH HAS ALLOWED SFC TEMPS TO RISE NEAR 50 DEGREES.
LATER TONIGHT THE LOW LEVEL JET IS PROGGED TO CONTINUE TO INCREASE
AS IT LIFTS NORTH ACROSS CENTRAL IL TOWARDS NORTHERN IL...WITH
GUIDANCE INDICATING SPEEDS AT 2-3KFT AGL HOVERING AROUND 40-50KT
OVERNIGHT. UPSTREAM ACROSS SOUTHERN IOWA/NORTHERN MISSOURI IS A WEAK
MID-LVL FEATURE THAT HAS SOME MID/HIGH DECK CLOUDS SLIDING
EAST...AND IS PROGGED TO ARRIVE LATER TONIGHT ACROSS THE FORECAST
AREA. LOW LEVEL MOISTURE TONIGHT WILL MAKE THE OVERNIGHT FORECAST
TRICKY...WITH THE POTENTIAL FOR PATCHY FOG TO DEVELOP AND LOW
CLOUDS. SEVERAL GUIDANCE MEMBERS ARE TRYING TO SLIDE A CHANNEL OF
INCREASED MOISTURE NORTHEAST ACROSS THE MID-MISSOURI VALLEY TOWARDS
NORTHERN IL...THIS IS MATCHED UP WITH THE STRENGTHENING MID-LVL
TROUGH AXIS THAT WILL BE PIVOTING INTO THE SOUTHERN PLAINS AROUND 9Z
FRI. HAVE HELD ONTO THE MENTION OF PATCHY FOG...HOWEVER CONFIDENCE
IN THIS DEVELOPING WILL REMAIN LOW AS IT APPEARS ENOUGH OF A T/TD
SPREAD WILL REMAIN. GUIDANCE HAS PUSHED BACK THE TIMING OF PRECIP
UNTIL CLOSER TO 9Z...BUT HAVE A STEADY INCREASE IN POPS BY DAYBREAK
FRI. TEMPS OVERNIGHT WILL REMAIN MILD...AND MAY NOT DIP MUCH AT ALL
WITH LOWS GENERALLY IN THE MID/UPR 30S TO AROUND 40 IN THE FAR
SOUTHERN CWFA.
FRIDAY... THE MID-LVL TROUGH WILL BE STEADILY DEEPENING AND
PUSHING EAST ACROSS IOWA/MISSOURI...ALLOWING THE LLVL MOISTURE
CHANNEL TO LIFT OVER NORTHERN IL/NORTHWEST IN. GUIDANCE HAS BEEN
STRUGGLING WITH HOW WIDESPREAD AND INTENSE PRECIP WILL END UP
BEING THROUGH MIDDAY...BUT THERE IS SOME CONSISTENCY WITH A BETTER
CHANCE FOR POPS IN THE EASTERN CWFA BY THE AFTERNOON HOURS AS
THE FRONTAL BOUNDARY STEADILY PUSHES EAST. THERE HAS BEEN SOME
SLOWING IN THE WARM LAYER DEPARTING TO THE EAST DURING THE
DAY...SO HAVE HELD ONTO THE WARMER TEMPS A LITTLE LONGER WHICH
WILL SLOW THE TRANSITION OVER FROM RAIN TO SNOW UNTIL MID/LATE
AFTN. THE PRESSURE GRADIENT WILL STEADILY TIGHTEN...WITH BREEZY
COLDER AIR STEADILY ADVECTING IN FROM THE WEST/NORTHWEST. EXPECT
STEADILY FALLING TEMPS BY MID/LATE FRI AFTN INTO THE LOW/MID
30S...WITH PRECIP QUICKLY TRANSITIONING BACK TO LIGHT SNOW. AT
THIS TIME IT DOES NOT APPEAR ANY ACCUMS WILL OCCUR.
BEACHLER
&&
.LONG TERM...
245 PM CST
FRIDAY NIGHT THROUGH THURSDAY...
THE CONCERN FOR THE EXTENDED FORECAST PERIOD WILL BE AN INTRUSION OF
ARCTIC AIR INTO THE REGION.
BY FRIDAY EVENING...THE SYSTEM RESPONSIBLE FOR FRIDAY`S PCPN WILL BE
LIFTING NEWD THROUGH THE ERN GREAT LAKES WHILE ARCTIC HIGH PRESSURE
BEGINS TO NOSE INTO THE NRN PLAINS. THE COMBINATION OF THE OLD NRN
STREAM LOW AND A SRN STREAM LOW OFF THE MID ATLANTIC COAST WITH
ANOTHER WEAK LOW DEVELOPING OVER WEST TEXAS WILL HELP FOCUS THE
ARCTIC HIGH TO PUSH SOUTH THROUGH THE CENTRAL PLAINS. COLD
ADVECTION SHOULD BEGIN THROUGH THE DAY ON SATURDAY SO THERE SHOULD
BBE LITTLE DIURNAL VARIATION IN TEMPERATURES FROM THE RELATIVELY
MILD CONDITIONS FRIDAY NIGHT UNTIL AROUND MIDDAY SATURDAY. THE MUCH
COLDER AIR SHOULD BEGIN TO PUSH INTO THE REGION SATURDAY
AFTERNOON...WITH TEMPERATURES DROPPING INTO THE SINGLE DIGITS AROUND
THE ROCKFORD AREA BY LATE AFTERNOON OR EARLY EVENING. THE POSITION
OF THE SFC HIGH OVER THE PLAINS AND RELATIVELY LOW PRESSURE OVER THE
EAST COAST WILL VARY LITTLE THROUGH THE REMAINDER OF THE WEEKEND AND
INTO EARLY NEXT WEEK...SO THE FETCH OF ARCTIC AIR WILL GO UNABATED.
WHILE A WEAK NRN STREAM SHORTWAVE SKIRTING ON THE SRN EDGE OF THE
ARCTIC HIGH MAY BRING A BRIEF PERIOD OF DENSE CLOUD COVER AND SOME
LIGHT SNOW...THERE SHOULD BE LITTLE IMPACT ON THE EXPECTED
TEMPERATURE TREND. TEMPERATURES SHOULD DROP BELOW 0F EARLY SUNDAY
MORNING OVER PORTIONS OF THE AREA NORTH OF I80 AND WEST OF THE FOX
VALLEY. SUB-ZERO MIN TEMPS ARE LIKELY FOR THE ENTIRE CWA BY MONDAY
MORNING...WITH THE EXCEPTION OF THE IMMEDIATE LAKEFRONT AND DOWNTOWN
CHICAGO. THE CORRIDOR FROM MCHENRY THROUGH DEKALB TO ROCHELLE
SEEING THE LOWEST TEMPERATURES OF THE PERIOD...WITH MINS OF
-8F TO -10F. WIND CHILLS WILL BE DANGEROUSLY LOW THROUGH THIS
PERIOD AS WELL WITH A PERSISTENT MODERATE NWLY PRESSURE GRADIENT
KEEPING 5 TO 10 MPH WINDS OVER THE AREA. WIND CHILL READINGS WILL
DROP BELOW -20F FOR MUCH OR ALL OF THE CWA SUNDAY AND MONDAY MORNING
AND WIND CHILL ADVISORIES WILL LIKELY BE ISSUED. HIGHS ON SUNDAY
AND MONDAY SHOULD REMAIN IN THE SINGLE DIGITS ABOVE ZERO FOR ALL BUT
THE FAR SERN PORTIONS OF THE CWA...WHICH SHOULD TOP OUT AT 11-12F.
BY TUESDAY MORNING...TEMPERATURES WILL STILL STILL RANGE FROM
THESINGLE DIGITS BELOW ZERO TO THE SINGLE DIGITS ABOVE ZERO...BUT
WIND CHILL READINGS SHOULD NOT BE QUITE AS LOW AS THE HIGH PRESSURE
SPREADS OVER THE LOCAL AREA AND INTO THE UPPER OHIO VALLEY...
ALLOWING WINDS TO DIMINISH. HIGH PRESSURE WILL LINGER OVER THE
REGION INTO MIDWEEK...THOUGH AMPLE SUNSHINE AND A SHUTTING DOWN OF
THE COLD ADVECTION SHOULD ALLOW TEMPERATURES TO MODERATE BY MIDWEEK
WITH TEMPERATURES REBOUNDING TO NEAR SEASONAL NORMAL LEVELS.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* LOWERING CIG/VSBY TRENDS OVERNIGHT AND FRIDAY MORNING.
* PRECIP CHANCES AND TIMING OVERNIGHT AND FRIDAY MORNING.
* LLWS LIKELY OVERNIGHT INTO MORNING.
LENNING
//DISCUSSION...UPDATED 00Z...
DESPITE WIDE DISAGREEMENT AMOUNG VARIOUS FORECAST MODELS...AND
LITTLE IN THE WAY OF EXISTING MVFR OR IFR OBSERVATIONS UPSTREAM
FROM THE AREA...A TREND TOWARD LOWER CONDITIONS AND LIGHT PRECIP
DOES APPEAR LIKELY BY MORNING. AM JUST NOT SURE HOW LOW. EVEN
SO...THE 00Z TAFS START THE LOWER CONDITIONS A BIT LATER THAN
PREVIOUS FORECASTS...BUT THE TIMING OF THE LOWEST CONDITIONS
TOMORROW MORNING STILL APPEARS TO BE ON TARGET.
MOTIVATION FOR THE SLOWER START COMES FROM A SOMEWHAT WARMER AND
DRIER BOUNDARY LAYER THAN WHAT SOME MODELS ARE SHOWING...AS
SUPPORTED BY THE LATEST AMDAR SOUNDINGS LOCALLY AND THE COMPLETE
LACK OF LOWER CEILINGS ANYWHERE IMMEDIATELY UPSTREAM ACROSS
IOWA...ILLINOIS...AND MISSOURI.
GIVEN THE APPROACH OF A LOW PRESSURE CENTER TO OUR NORTHWEST AND
A COLD FRONT TO OUR WEST...THE SOURCE REGION FOR OUR LOW LEVEL
AIRMASS OVERNIGHT AND IN THE MORNING APPEARS TO BE EASTERN OK AND
WESTERN AR WHERE A FEW SITES ARE REPORTING SCT-BKN 040-055. THE
NAM AND RAP SUGGEST THE RELATIVELY MOIST AIRMASS FROM THIS REGION
MIGHT MIX INTO THE THE LOCALLY COLDER AIR SOMEWHERE IN THE 08Z
TIMEFRAME...AFTER WHICH LOWER LEVEL SATURATION AND SOME LIGHT RAIN
OR DRIZZLE WOULD BE EXPECTED TO DEVELOP FAIRLY QUICKLY.
AS THE FRONT MOVES THROUGH THE AREA DURING THE LATE MORNING AND
WINDS TURN WESTERLY...LOW CLOUDS MAY HANG AROUND THROUGH THE REST
OF THE DAY BUT THE RA/DZ SHOULD COME TO AN END.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW TO MEDIUM FOR CIGS/VSBYS OVERNIGHT AND FRIDAY MORNING.
* MEDIUM FOR CIGS AND MEDIUM HIGH FOR VSBYS FRIDAY AFTERNOON.
* MEDIUM FOR WINDS...AND MEDIUM TO HIGH FOR LLWS TONIGHT. LLWS MAY
NOT PERSIST AS LONG IN THE MORNING AS SHOWN IN THE TAFS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY AND SUNDAY...DRY. MVFR POSSIBLE. GUSTY NORTHWEST WINDS.
VERY COLD SUNDAY.
* MONDAY AND TUESDAY...DRY/VFR. WESTERLY WINDS. VERY COLD MONDAY.
* WEDNESDAY...CHANCE OF SNOW SHOWERS. MVFR POSSIBLE. WEST WINDS.
LENNING
&&
.MARINE...
323 PM CST
A VERY ACTIVE PATTERN IS SETTING UP FOR LAKE MICHIGAN FOR THE NEXT
SEVERAL DAYS.
A WARM FRONT EXTENDS FROM LOW PRESSURE OVER SRN MINNESOTA EAST
ACROSS CENTRAL LAKE MICHIGAN. GUSTY SOUTH WINDS TO ARND 25KT WILL
PERSIST INTO THE EVENING OVER THE SOUTHERN END OF THE LAKE WHILE
WINDS WILL START OUT SELY OVER THE NORTHERN PORTIONS OF THE LAKE.
THE LOW IS EXPECTED TO TRACK ACROSS THE CENTER OF THE LAKE
FRIDAY...WITH THE SLY WINDS OVER THE SRN HALF OF THE LAKE INCREASING
TO ARND 30KT...WHILE WINDS OVER THE NORTH END OF THE LAKE STRENGTHEN
TO ARND 30KT AND BECOME ELY. AS THE LOW PASSES OFF TO THE EAST
FRIDAY NIGHT...STRONG ARCTIC HIGH PRESSURE WILL BUILD INTO THE
CENTRAL PLAINS...SETTING UP AN EXTENDED PERIOD OF STRONG NWLY WINDS
BRINGING MUCH COLDER AIR ACROSS THE LAKE. THE VERY COLD AIR WILL
BEGIN TO OVERSPREAD THE LAKE SATURDAY NIGHT WITH THE COLD AIR
EXPECTED TO PERSIST INTO EARLY NEXT WEEK. A BRIEF PERIOD OF NWLY
GALES ARE POSSIBLE FOR FRIDAY NIGHT WITH A STRONG NWLY GRADIENT
DEVELOPING BETWEEN THE EXITING LOW AND THE HIGH BUILDING INTO THE
CENTRAL PLAINS. THE WINDOW OF OPPORTUNITY FOR GALES FRIDAY NIGHT
SHOULD BE RELATIVELY SHORT AS THE LOW QUICKLY LIFTS INTO QUEBEC AND
THE GRADIENT OVER THE LAKE RELAXES. THE NWLY GRADIENT SHOULD
STRENGTHEN AGAIN LATE SATURDAY NIGHT AND SUNDAY AS A MID LEVEL
IMPULSE TRACKS THROUGH THE UPPER GREAT LAKES AND THE SURGE OF VERY
COLD AIR OVERSPREADS THE LAKE. THE COMBINATION OF STRONG
WINDS...POSSIBLY REACHING GALE FORCE SUNDAY AFTERNOON AND
EVENING...AND VERY COLD AIR WILL COMBINE TO BRING A PERIOD OF
MODERATE FREEZING SPRAY TO THE ENTIRE LAKE...FROM SATURDAY NIGHT
THROUGH MONDAY. BY MONDAY NIGHT...THE ARCTIC HIGH WILL BEGIN TO
OVERSPREAD THE LAKE ALLOWING WINDS TO DIMINISH AND END THE THREAT OF
FREEZING SPRAY. RELATIVELY LIGHT WLY WINDS ARE EXPECTED BY
WEDNESDAY AS THE CENTER OF THE HIGH PRESSURE SLIDES SOUTH OF THE
LAKE WHILE WEAK LOW PRESSURE BEGINS TO DEVELOP OVER THE WESTERN
PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...3 PM FRIDAY TO 3
PM SATURDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 PM FRIDAY TO 9
PM SATURDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
611 PM CST THU JAN 14 2016
.SHORT TERM...
225 PM CST
THROUGH FRIDAY...
STARK CONTRAST THIS AFTERNOON FROM THE PAST FEW DAYS...AS THE REGION
SEES A BRIEF LULL IN THE DEEP FREEZE WITH A MID-JANUARY THAW. THE
THERMAL TROUGH HAS RETREATED NORTH ALLOWING MUCH WARMER AIR TO
ADVECT IN ON THE NOSE OF A STRENGTHENING LOW LEVEL JET AT 850MB. THE
RISE IN HEIGHTS ALOFT HAS ALLOWED AN EROSION OF THE LOW/MID LEVEL
CLOUDS...WHICH COUPLED WITH THE WARM AIR ADVECTION HAS ALLOWED SFC
TEMPS TO PUSH INTO THE LOW/MID 40S IN MANY AREAS AND QUICKLY MELTING
THE SNOWPACK. VISIBLE SATELLITE IMAGERY THIS AFTERNOON SHOWS THE
RECEEDING SNOWPACK QUITE WELL. ALONG THE SOUTHERN TIER OF
COUNTIES...MAINLY SOUTH OF I-80...THE SNOWPACK WAS LESS TO BEGIN
WITH...WHICH HAS ALLOWED SFC TEMPS TO RISE NEAR 50 DEGREES.
LATER TONIGHT THE LOW LEVEL JET IS PROGGED TO CONTINUE TO INCREASE
AS IT LIFTS NORTH ACROSS CENTRAL IL TOWARDS NORTHERN IL...WITH
GUIDANCE INDICATING SPEEDS AT 2-3KFT AGL HOVERING AROUND 40-50KT
OVERNIGHT. UPSTREAM ACROSS SOUTHERN IOWA/NORTHERN MISSOURI IS A WEAK
MID-LVL FEATURE THAT HAS SOME MID/HIGH DECK CLOUDS SLIDING
EAST...AND IS PROGGED TO ARRIVE LATER TONIGHT ACROSS THE FORECAST
AREA. LOW LEVEL MOISTURE TONIGHT WILL MAKE THE OVERNIGHT FORECAST
TRICKY...WITH THE POTENTIAL FOR PATCHY FOG TO DEVELOP AND LOW
CLOUDS. SEVERAL GUIDANCE MEMBERS ARE TRYING TO SLIDE A CHANNEL OF
INCREASED MOISTURE NORTHEAST ACROSS THE MID-MISSOURI VALLEY TOWARDS
NORTHERN IL...THIS IS MATCHED UP WITH THE STRENGTHENING MID-LVL
TROUGH AXIS THAT WILL BE PIVOTING INTO THE SOUTHERN PLAINS AROUND 9Z
FRI. HAVE HELD ONTO THE MENTION OF PATCHY FOG...HOWEVER CONFIDENCE
IN THIS DEVELOPING WILL REMAIN LOW AS IT APPEARS ENOUGH OF A T/TD
SPREAD WILL REMAIN. GUIDANCE HAS PUSHED BACK THE TIMING OF PRECIP
UNTIL CLOSER TO 9Z...BUT HAVE A STEADY INCREASE IN POPS BY DAYBREAK
FRI. TEMPS OVERNIGHT WILL REMAIN MILD...AND MAY NOT DIP MUCH AT ALL
WITH LOWS GENERALLY IN THE MID/UPR 30S TO AROUND 40 IN THE FAR
SOUTHERN CWFA.
FRIDAY... THE MID-LVL TROUGH WILL BE STEADILY DEEPENING AND
PUSHING EAST ACROSS IOWA/MISSOURI...ALLOWING THE LLVL MOISTURE
CHANNEL TO LIFT OVER NORTHERN IL/NORTHWEST IN. GUIDANCE HAS BEEN
STRUGGLING WITH HOW WIDESPREAD AND INTENSE PRECIP WILL END UP
BEING THROUGH MIDDAY...BUT THERE IS SOME CONSISTENCY WITH A BETTER
CHANCE FOR POPS IN THE EASTERN CWFA BY THE AFTERNOON HOURS AS
THE FRONTAL BOUNDARY STEADILY PUSHES EAST. THERE HAS BEEN SOME
SLOWING IN THE WARM LAYER DEPARTING TO THE EAST DURING THE
DAY...SO HAVE HELD ONTO THE WARMER TEMPS A LITTLE LONGER WHICH
WILL SLOW THE TRANSITION OVER FROM RAIN TO SNOW UNTIL MID/LATE
AFTN. THE PRESSURE GRADIENT WILL STEADILY TIGHTEN...WITH BREEZY
COLDER AIR STEADILY ADVECTING IN FROM THE WEST/NORTHWEST. EXPECT
STEADILY FALLING TEMPS BY MID/LATE FRI AFTN INTO THE LOW/MID
30S...WITH PRECIP QUICKLY TRANSITIONING BACK TO LIGHT SNOW. AT
THIS TIME IT DOES NOT APPEAR ANY ACCUMS WILL OCCUR.
BEACHLER
&&
.LONG TERM...
245 PM CST
FRIDAY NIGHT THROUGH THURSDAY...
THE CONCERN FOR THE EXTENDED FORECAST PERIOD WILL BE AN INTRUSION OF
ARCTIC AIR INTO THE REGION.
BY FRIDAY EVENING...THE SYSTEM RESPONSIBLE FOR FRIDAY`S PCPN WILL BE
LIFTING NEWD THROUGH THE ERN GREAT LAKES WHILE ARCTIC HIGH PRESSURE
BEGINS TO NOSE INTO THE NRN PLAINS. THE COMBINATION OF THE OLD NRN
STREAM LOW AND A SRN STREAM LOW OFF THE MID ATLANTIC COAST WITH
ANOTHER WEAK LOW DEVELOPING OVER WEST TEXAS WILL HELP FOCUS THE
ARCTIC HIGH TO PUSH SOUTH THROUGH THE CENTRAL PLAINS. COLD
ADVECTION SHOULD BEGIN THROUGH THE DAY ON SATURDAY SO THERE SHOULD
BBE LITTLE DIURNAL VARIATION IN TEMPERATURES FROM THE RELATIVELY
MILD CONDITIONS FRIDAY NIGHT UNTIL AROUND MIDDAY SATURDAY. THE MUCH
COLDER AIR SHOULD BEGIN TO PUSH INTO THE REGION SATURDAY
AFTERNOON...WITH TEMPERATURES DROPPING INTO THE SINGLE DIGITS AROUND
THE ROCKFORD AREA BY LATE AFTERNOON OR EARLY EVENING. THE POSITION
OF THE SFC HIGH OVER THE PLAINS AND RELATIVELY LOW PRESSURE OVER THE
EAST COAST WILL VARY LITTLE THROUGH THE REMAINDER OF THE WEEKEND AND
INTO EARLY NEXT WEEK...SO THE FETCH OF ARCTIC AIR WILL GO UNABATED.
WHILE A WEAK NRN STREAM SHORTWAVE SKIRTING ON THE SRN EDGE OF THE
ARCTIC HIGH MAY BRING A BRIEF PERIOD OF DENSE CLOUD COVER AND SOME
LIGHT SNOW...THERE SHOULD BE LITTLE IMPACT ON THE EXPECTED
TEMPERATURE TREND. TEMPERATURES SHOULD DROP BELOW 0F EARLY SUNDAY
MORNING OVER PORTIONS OF THE AREA NORTH OF I80 AND WEST OF THE FOX
VALLEY. SUB-ZERO MIN TEMPS ARE LIKELY FOR THE ENTIRE CWA BY MONDAY
MORNING...WITH THE EXCEPTION OF THE IMMEDIATE LAKEFRONT AND DOWNTOWN
CHICAGO. THE CORRIDOR FROM MCHENRY THROUGH DEKALB TO ROCHELLE
SEEING THE LOWEST TEMPERATURES OF THE PERIOD...WITH MINS OF
-8F TO -10F. WIND CHILLS WILL BE DANGEROUSLY LOW THROUGH THIS
PERIOD AS WELL WITH A PERSISTENT MODERATE NWLY PRESSURE GRADIENT
KEEPING 5 TO 10 MPH WINDS OVER THE AREA. WIND CHILL READINGS WILL
DROP BELOW -20F FOR MUCH OR ALL OF THE CWA SUNDAY AND MONDAY MORNING
AND WIND CHILL ADVISORIES WILL LIKELY BE ISSUED. HIGHS ON SUNDAY
AND MONDAY SHOULD REMAIN IN THE SINGLE DIGITS ABOVE ZERO FOR ALL BUT
THE FAR SERN PORTIONS OF THE CWA...WHICH SHOULD TOP OUT AT 11-12F.
BY TUESDAY MORNING...TEMPERATURES WILL STILL STILL RANGE FROM
THESINGLE DIGITS BELOW ZERO TO THE SINGLE DIGITS ABOVE ZERO...BUT
WIND CHILL READINGS SHOULD NOT BE QUITE AS LOW AS THE HIGH PRESSURE
SPREADS OVER THE LOCAL AREA AND INTO THE UPPER OHIO VALLEY...
ALLOWING WINDS TO DIMINISH. HIGH PRESSURE WILL LINGER OVER THE
REGION INTO MIDWEEK...THOUGH AMPLE SUNSHINE AND A SHUTTING DOWN OF
THE COLD ADVECTION SHOULD ALLOW TEMPERATURES TO MODERATE BY MIDWEEK
WITH TEMPERATURES REBOUNDING TO NEAR SEASONAL NORMAL LEVELS.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* LOWERING CIG/VSBY TRENDS OVERNIGHT AND FRIDAY MORNING.
* PRECIP CHANCES AND TIMING OVERNIGHT AND FRIDAY MORNING.
* LLWS LIKELY OVERNIGHT INTO MORNING.
LENNING
//DISCUSSION...UPDATED 00Z...
DESPITE WIDE DISAGREEMENT AMOUNG VARIOUS FORECAST MODELS...AND
LITTLE IN THE WAY OF EXISTING MVFR OR IFR OBSERVATIONS UPSTREAM
FROM THE AREA...A TREND TOWARD LOWER CONDITIONS AND LIGHT PRECIP
DOES APPEAR LIKELY BY MORNING. AM JUST NOT SURE HOW LOW. EVEN
SO...THE 00Z TAFS START THE LOWER CONDITIONS A BIT LATER THAN
PREVIOUS FORECASTS...BUT THE TIMING OF THE LOWEST CONDITIONS
TOMORROW MORNING STILL APPEARS TO BE ON TARGET.
MOTIVATION FOR THE SLOWER START COMES FROM A SOMEWHAT WARMER AND
DRIER BOUNDARY LAYER THAN WHAT SOME MODELS ARE SHOWING...AS
SUPPORTED BY THE LATEST AMDAR SOUNDINGS LOCALLY AND THE COMPLETE
LACK OF LOWER CEILINGS ANYWHERE IMMEDIATELY UPSTREAM ACROSS
IOWA...ILLINOIS...AND MISSOURI.
GIVEN THE APPROACH OF A LOW PRESSURE CENTER TO OUR NORTHWEST AND
A COLD FRONT TO OUR WEST...THE SOURCE REGION FOR OUR LOW LEVEL
AIRMASS OVERNIGHT AND IN THE MORNING APPEARS TO BE EASTERN OK AND
WESTERN AR WHERE A FEW SITES ARE REPORTING SCT-BKN 040-055. THE
NAM AND RAP SUGGEST THE RELATIVELY MOIST AIRMASS FROM THIS REGION
MIGHT MIX INTO THE THE LOCALLY COLDER AIR SOMEWHERE IN THE 08Z
TIMEFRAME...AFTER WHICH LOWER LEVEL SATURATION AND SOME LIGHT RAIN
OR DRIZZLE WOULD BE EXPECTED TO DEVELOP FAIRLY QUICKLY.
AS THE FRONT MOVES THROUGH THE AREA DURING THE LATE MORNING AND
WINDS TURN WESTERLY...LOW CLOUDS MAY HANG AROUND THROUGH THE REST
OF THE DAY BUT THE RA/DZ SHOULD COME TO AN END.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW TO MEDIUM FOR CIGS/VSBYS OVERNIGHT AND FRIDAY MORNING.
* MEDIUM FOR CIGS AND MEDIUM HIGH FOR VSBYS FRIDAY AFTERNOON.
* MEDIUM FOR WINDS...AND MEDIUM TO HIGH FOR LLWS TONIGHT. LLWS MAY
NOT PERSIST AS LONG IN THE MORNING AS SHOWN IN THE TAFS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
* SATURDAY AND SUNDAY...DRY. MVFR POSSIBLE. GUSTY NORTHWEST WINDS.
VERY COLD SUNDAY.
* MONDAY AND TUESDAY...DRY/VFR. WESTERLY WINDS. VERY COLD MONDAY.
* WEDNESDAY...CHANCE OF SNOW SHOWERS. MVFR POSSIBLE. WEST WINDS.
LENNING
&&
.MARINE...
323 PM CST
A VERY ACTIVE PATTERN IS SETTING UP FOR LAKE MICHIGAN FOR THE NEXT
SEVERAL DAYS.
A WARM FRONT EXTENDS FROM LOW PRESSURE OVER SRN MINNESOTA EAST
ACROSS CENTRAL LAKE MICHIGAN. GUSTY SOUTH WINDS TO ARND 25KT WILL
PERSIST INTO THE EVENING OVER THE SOUTHERN END OF THE LAKE WHILE
WINDS WILL START OUT SELY OVER THE NORTHERN PORTIONS OF THE LAKE.
THE LOW IS EXPECTED TO TRACK ACROSS THE CENTER OF THE LAKE
FRIDAY...WITH THE SLY WINDS OVER THE SRN HALF OF THE LAKE INCREASING
TO ARND 30KT...WHILE WINDS OVER THE NORTH END OF THE LAKE STRENGTHEN
TO ARND 30KT AND BECOME ELY. AS THE LOW PASSES OFF TO THE EAST
FRIDAY NIGHT...STRONG ARCTIC HIGH PRESSURE WILL BUILD INTO THE
CENTRAL PLAINS...SETTING UP AN EXTENDED PERIOD OF STRONG NWLY WINDS
BRINGING MUCH COLDER AIR ACROSS THE LAKE. THE VERY COLD AIR WILL
BEGIN TO OVERSPREAD THE LAKE SATURDAY NIGHT WITH THE COLD AIR
EXPECTED TO PERSIST INTO EARLY NEXT WEEK. A BRIEF PERIOD OF NWLY
GALES ARE POSSIBLE FOR FRIDAY NIGHT WITH A STRONG NWLY GRADIENT
DEVELOPING BETWEEN THE EXITING LOW AND THE HIGH BUILDING INTO THE
CENTRAL PLAINS. THE WINDOW OF OPPORTUNITY FOR GALES FRIDAY NIGHT
SHOULD BE RELATIVELY SHORT AS THE LOW QUICKLY LIFTS INTO QUEBEC AND
THE GRADIENT OVER THE LAKE RELAXES. THE NWLY GRADIENT SHOULD
STRENGTHEN AGAIN LATE SATURDAY NIGHT AND SUNDAY AS A MID LEVEL
IMPULSE TRACKS THROUGH THE UPPER GREAT LAKES AND THE SURGE OF VERY
COLD AIR OVERSPREADS THE LAKE. THE COMBINATION OF STRONG
WINDS...POSSIBLY REACHING GALE FORCE SUNDAY AFTERNOON AND
EVENING...AND VERY COLD AIR WILL COMBINE TO BRING A PERIOD OF
MODERATE FREEZING SPRAY TO THE ENTIRE LAKE...FROM SATURDAY NIGHT
THROUGH MONDAY. BY MONDAY NIGHT...THE ARCTIC HIGH WILL BEGIN TO
OVERSPREAD THE LAKE ALLOWING WINDS TO DIMINISH AND END THE THREAT OF
FREEZING SPRAY. RELATIVELY LIGHT WLY WINDS ARE EXPECTED BY
WEDNESDAY AS THE CENTER OF THE HIGH PRESSURE SLIDES SOUTH OF THE
LAKE WHILE WEAK LOW PRESSURE BEGINS TO DEVELOP OVER THE WESTERN
PLAINS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...3 PM FRIDAY TO 3
PM SATURDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...3 PM FRIDAY TO 9
PM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
601 PM CST THU JAN 14 2016
.SHORT TERM...(Tonight)
ISSUED AT 322 PM CST THU JAN 14 2016
20z/2pm surface analysis shows 1022mb high anchored over Georgia,
while a 997mb low organizes over eastern South Dakota. The pressure
gradient between these two features will continue to provide a
warm/southerly flow across central Illinois tonight, which will keep
temperatures several degrees warmer than in previous nights. Thanks
to southerly winds of 10 to 15mph through the night and increasing
clouds, overnight low temperatures will remain in the upper 30s and
lower 40s. As the South Dakota low tracks eastward into Wisconsin,
it will pull a cold front toward the region later tonight.
Increasing low-level moisture along/ahead of the boundary will
eventually yield a few light rain showers after midnight. HRRR
suggests the precip will develop along/west of a Champaign to
Taylorville line between 06z and 09z...then will spread further
eastward across the remainder of the area toward dawn. Since
forecast soundings do not fully saturate through a deep layer...will
maintain just chance PoPs overnight until deeper moisture arrives
Friday morning.
.LONG TERM...(Friday through Thursday)
ISSUED AT 322 PM CST THU JAN 14 2016
Models in good agreement with the system that will be moving through
the CWA Friday, as the low pressure area moves across the Great
Lakes with the trailing cold front sliding across the state during
the morning. Once this occurs, much colder air will pour into the
area with temperatures falling during the afternoon hours. During
the day, all the pcpn will be liquid, but when the temps begin to
fall the pcpn will become mixed with snow as it is ending. Do not
see any accumulation of snowfall with this system. Then, after a
brief period of dry weather thru Saturday evening, a clipper system
will move toward the area and bring snow to the area beginning late
Sat night and continuing through Sunday morning. By Sun afternoon,
the snow will have ended and moved east of the area.
Temps will be warm one more day, tomorrow, but then fall beginning
in the afternoon. So, look for morning or late morning highs. Temps
will continue to fall during the night, and then go back up on Sat,
but remain below normal. Then much colder air will pour into the
area for the weekend, with temps below zero in the north Sat night.
Below zero temps are expected again Sun night, but over most of the
area...with only southeast IL seeing above zero temps...though in
the single digits.
Next chance of pcpn will be another clipper system coming toward the
area, but tracking mostly south of the CWA for Tue into Tue night.
Will have a chance of snow in the southwest third of the area for
Tue and then a slight chance of snow over the whole area for Tue
night. Then toward the later half of the week, another weather
system will move toward the area. Models show much disagreement with
this system at this point, so will just go with the blend for now
and have a slight chance of pcpn for Wed night and then a chance
across the southern half of the CWA for Thur. P-type will be mainly
snow in the north, but a mix of rain and snow in the south.
Temps will start cold, but gradually warm back toward normal for Wed
and Thur.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 600 PM CST THU JAN 14 2016
VFR conditions will prevail through the evening before low-level
moisture increases ahead of an approaching cold front later
tonight. NAM12, HRRR, and namdng consensus still pointing toward
MVFR clouds and spotty showers developing over central IL between
08z and 12z, including our TAF sites. Profiles never become
saturated through a deep layer, so will only mention VCSH with the
front. The HRRR and NAM/GFS forecast soundings support IFR clouds
just behind the front for a couple hours. Therefore, have
introduced IFR cloud heights at all terminal sites for the mid
morning time frame. Once the boundary pushes east, gusty
southerly winds will veer to the west Friday morning. FROPA
timing appears to be about 16z at KPIA and closer to 18z at KCMI.
While sustained surface winds will remain quite brisk at around
14-15kt tonight, radar VWP plots and the NAM are showing a strong
45-50kt 925mb jet developing. Have therefore continued to include low-
level wind shear at the TAF sites tonight.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1140 AM CST WED JAN 13 2016
.UPDATE...
1015 AM CST
THE GOING FORECAST AND MESSAGE FOR TODAY REMAIN IN GOOD SHAPE
WITH A PERIOD OF LIGHT SNOW FOR A GOOD PORTION OF THE FORECAST
AREA THROUGH MAINLY 3-4 PM. HAVE ONLY MADE SUBTLE ADJUSTMENTS TO
SPECIFIC HOURLY TIMING. FOR IMPACTS...THIS CONTINUES TO LOOK LIKE
MOST OF THE SNOW OUTSIDE OF SOME SPOTTY SNOW SHOWERS TO BE MAINLY
DONE BY 4 PM AND THUS SANDWICHED BETWEEN THE PRIMARY COMMUTES FOR
MANY. OBVIOUSLY LINGERING IMPACTS OF LIGHTLY SNOW COVERED ROADS
MAY RESULT.
LIGHT SNOW WITH 6-9SM VISIBILITY IS BEING OBSERVED ACROSS MOST OF
THE NORTHERN ILLINOIS CWA AS OF 1000 AM WITHIN BROAD WARM
ADVECTION...WITH EVEN LOCAL VISIBILITY AROUND 3SM OUT OUR WINDOW
HERE IN ROMEOVILLE. THE WARM ADVECTION FLOW HAS GRADUALLY BEEN
STRENGTHENING PER THE DVN AND LOT VAD WIND PROFILERS AND THUS THE
ISENTROPIC ASCENT HAS AS WELL. THIS SHOULD FURTHER INCREASE AS THE
PRIMARY SHORT WAVE DISTURBANCE LOCATED OVER SOUTHERN MN PROGRESSES
QUICKLY TOWARD THE AREA. THE RAP ISENTROPIC ANALYSIS CAPTURES WHAT
IS OCCURRING WELL WITH A COMPACT AREA OF ASCENT LINING UP WELL
WITH RADAR...AND ITS THERMAL PROFILES ARE ALSO PRETTY CLOSE TO
RECENT AMDAR DATA. SO CONFIDENCE IN THE RAP AND HRRR SOLUTIONS
REMAIN FAIRLY HIGH AND THUS ONLY MINOR MASSAGING TO THE CURRENT
FORECAST WITH THIS DATA.
THE THERMAL PROFILE ON RECENT AMDAR DATA FROM NEAR MDW INDICATES
THE LOWEST 10,000 FT OF THE SOUNDING LOCATED BETWEEN -10C AND
-15C...CLASSIC OF A COLD AIR MASS. WITH ROOM FOR A LITTLE BIT OF
WET BULB COOLING TO OFFSET THE WARM ADVECTION...THE THERMAL
PROFILE SHOULD LIKELY REMAIN AS SUCH THROUGH THE NEXT SEVERAL HOUR
SNOWFALL...AND THUS ASSIST IN SOME LARGE SNOWFLAKE SIZE AT LEAST
IN THE CLOUD LAYER. SO STILL THINKING A COUPLE TENTHS TO ONE HALF
INCH WITH LOCALIZED ONE INCH AMOUNTS OF FLUFFY SNOW POSSIBLE.
MTF
&&
.SHORT TERM...
353 AM CST
TODAY AND TONIGHT...
FOCUS FOR TODAY IS ON ANOTHER LIGHT(ER) SNOW EVENT DEVELOPING
FROM MID-MORNING THROUGH THIS AFTERNOON.
REGIONAL RADAR MOSAIC DEPICTING SOME WEAK RETURNS ACROSS PORTIONS
OF CENTRAL IOWA AT 09Z...ASSOCIATED WITH ISENTROPIC WARM ADVECTION
ASCENT WITH A MINOR AMPLITUDE SHORT WAVE TROUGH PROPAGATING
SOUTHEAST ACROSS EASTERN NEBRASKA/WESTERN IOWA PER GOES WATER
VAPOR IMAGERY. SUITE OF GUIDANCE INDICATE THIS AREA OF LIGHT SNOW
WILL EXPAND EASTWARD INTO SOUTHERN WI/NORTHERN IL AND NORTHWEST
INDIANA THROUGH MID-DAY...AS ANOTHER FASTER MOVING DISTURBANCE
RIPPLES QUICKLY FROM THE CANADIAN PRAIRIES/NORTHERN PLAINS TO THE
FORECAST AREA THIS AFTERNOON. LATEST WRF-NAM/RAP GUIDANCE
INDICATES MODEST LIFT INTERSECTING ABOUT A 75 MB DEEP DENDRITIC
GROWTH ZONE BETWEEN ROUGHLY 600-700 MB...THOUGH HIGHER RELATIVE
HUMIDITY IS LOCATED BENEATH THIS ZONE AND FORCING IS
WEAKER/SHORTER LIVED THAN WITH THE MUCH STRONGER SYSTEM OF THIS
PAST MONDAY. VARIOUS MODEL QPF/S ARE ONLY A COUPLE OF HUNDREDTHS
OF AN INCH...WITH EXPECTED SNOW/LIQUID RATIOS PERHAPS 16-19:1
YIELDING GENERALLY AN INCH OR LESS. SURFACE TEMPS WILL RISE INTO
THE TEENS/LOW 20S THROUGH THIS AFTERNOON SO SNOW SHOULD HAVE NO
TROUBLE STICKING. THE SECOND QUICK-MOVING MID-LEVEL SHORT WAVE IS
PROGGED TO MOVE EAST OF THE CWA BY THIS EVENING...BRINGING
PRECIPITATION TO AN END. WITH WEAK SURFACE REFLECTION/WARM FRONT
MOVING TO THE EAST-NORTHEAST OF THE AREA TONIGHT...TEMPERATURES
LOOK TO REMAIN NEARLY STEADY FROM LATE DAY HIGHS. READINGS IN THE
20S/HIGH TEENS OVERNIGHT SHOULD BE A WELCOME RESPITE FROM THE
SINGLE DIGITS AND LOCAL SUB-ZERO NUMBERS OF EARLY THIS MORNING.
RATZER
&&
.LONG TERM...
353 AM CST
THURSDAY THROUGH TUESDAY...
MILDER WEATHER...A BRIEF JANUARY THAW...WILL START THE EXTENDED
PERIOD THURSDAY INTO FRIDAY AS UPPER FLOW FLATTENS AHEAD OF AN
UPPER TROUGH WHICH IS CURRENTLY APPROACHING THE PACIFIC COAST.
MODELS HAVE TRENDED FARTHER SOUTH WITH SOUTHERN STREAM ENERGY NOW
TRACKING INTO NORTHERN MEXICO...WITH DOMINANT NORTHERN STREAM
SURFACE LOW PROGGED TO MOVE JUST NORTH OF THE CWA THURSDAY NIGHT.
WITH SOUTH WINDS AND AIR TEMPS HOLDING ABOVE
FREEZING...DRIZZLE/LIGHT RAIN EXPECTED TO DEVELOP LATE THURSDAY
NIGHT AND CONTINUE INTO FRIDAY AS MID-LEVEL WAVE AND SURFACE LOW
PASS. SOME CONCERNS EXIST THAT SNOW COVER AND COLD GROUND MAY KEEP
SURFACE TEMPS NEAR FREEZING THURSDAY NIGHT WHICH COULD RESULT IN
PATCHY FREEZING DRIZZLE...AND THE POTENTIAL FOR FOG INCREASES AS
WELL WITH MOIST ADVECTION FROM THE SOUTH AND DEW POINT TEMPS
CLIMBING ABOVE FREEZING THURSDAY NIGHT/FRIDAY MORNING. THE COLUMN
DOES COOL ENOUGH TO CHANGE PRECIPITATION OVER TO SNOW POST-
FRONTALLY FRIDAY AFTERNOON/NIGHT... THOUGH LITTLE ACCUMULATION
EXPECTED WITH ONLY LIGHT QPF DEPICTED IN THE COLDER AIR.
MEDIUM/LONG RANGE SOLUTIONS CONTINUE TO PULL ARCTIC AIR BACK INTO
THE REGION SATURDAY NIGHT INTO EARLY NEXT WEEK...WITH ANOTHER PUSH
OF -20 DEG 850 MB AIR INDICATED BY BOTH ECMWF/GFS SUNDAY/SUNDAY
NIGHT. SINGLE DIGIT TEMPS ARRIVE SATURDAY NIGHT AND
SUNDAY...LIKELY DIPPING BELOW ZERO IN MANY SPOTS BY MONDAY
MORNING. SURFACE HIGH PRESSURE RIDGE MOVES ACROSS THE REGION
MONDAY/MONDAY NIGHT...THEN FLOW FLATTENS WITH ANOTHER MODERATING
TREND APPEARING TUESDAY INTO MID-NEXT WEEK.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SNOW THROUGH MID AFTERNOON REDUCING VSBY TO MVFR AND POSSIBLY
IFR AT TIMES. LIGHT ACCUMULATION LESS THAN AN INCH POSSIBLE.
* POTENTIAL FOR MVFR/IFR CIGS OVERNIGHT.
BMD
//DISCUSSION...UPDATED 18Z...
LIGHT SNOW IS IN PLACE ACROSS NORTHERN ILLINOIS EARLY THIS
AFTERNOON AND IS EXPECTED TO PERSIST FOR A FEW MORE HOURS WITH
CONDITIONS IMPROVING AROUND 21Z. SO FAR VSBY HAS BEEN HIGHER THAN
ANTICIPATED...HOWEVER FORECAST SOUNDINGS SUGGEST THERE COULD BE
SOME ENHANCEMENT OVER THE NEXT FEW HOURS...AND THIS IS BEING SEEN
ACROSS FAR SOUTH/SOUTHEAST WISCONSIN WHERE A FEW SITES ARE
REPORTING 2-3SM. LIGHT ACCUMULATIONS UNDER AND INCH STILL APPEAR
POSSIBLE. UPPER LEVEL WAVE IS PROGGED TO PASS OVERHEAD MID
AFTERNOON WITH DRIER MID LEVEL MOVING IN BEHIND. THIS SHOULD ALLOW
PRECIP TO END.
ATTENTION WILL TURN TO CIGS BEHIND THE WAVE WITH SEVERAL MODELS
SUGGESTING THE POSSIBILITY FOR IFR OR LOW END MVFR CIGS DEVELOPING
LATE THIS EVENING AND OVERNIGHT. IT APPEARS THE TERMINALS WILL
BE NEAR THE EDGE OF THE LOWER STRATUS WHICH WILL BE MORE
WIDESPREAD OVER WISCONSIN...AND GIVEN TYPICAL MOIST BIAS OF THE
NAM/MET CONFIDENCE IS TOO LOW IN THE MEANTIME TO MENTION IN THE
TAF.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH CONFIDENCE IN SNOW TIMING/DURATION. LOW-MEDIUM ON
VSBY.
* LOW CONFIDENCE IN CIG TRENDS LATE THIS EVENING AND TONIGHT.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...CHANCE OF RAIN/DRIZZLE. IFR/LIFR LIKELY. SOUTH
WINDS.
* FRIDAY...RAIN CHANGING TO SNOW. IFR LIKELY. SOUTHWEST WINDS
SHIFTING NORTHWEST.
* SATURDAY AND SUNDAY...DRY. MVFR POSSIBLE. GUSTY NORTHWEST WINDS.
* MONDAY...DRY/VFR. NORTHWEST WINDS.
* TUESDAY...DRY. MVFR POSSIBLE. WESTERLY WINDS.
&&
.MARINE...
312 AM...HIGH PRESSURE OVER THE OHIO VALLEY WILL MOVE SOUTHEAST
TODAY AS LOW PRESSURE DEVELOPS OVER LAKE SUPERIOR. THIS WILL
MAINTAIN A WEST/SOUTHWEST WIND IN THE 15-25KT RANGE THROUGH THIS
EVENING. WINDS WILL SLOWLY DIMINISH TONIGHT WITH LIGHT WINDS
EXPECTED OVER NORTHERN PORTIONS OF THE LAKE THURSDAY. SOUTHERLY
WINDS WILL CONTINUE OVER THE SOUTHERN PART OF THE LAKE AS ANOTHER
LOW MOVES ACROSS THE NORTHERN PLAINS THURSDAY AND ACROSS THE
WESTERN LAKES REGION FRIDAY. DUE TO THE TRACK OF THE LOW ACROSS
THE LAKE...CHANGES TO WIND DIRECTIONS CAN BE EXPECTED WITH LATER
FORECASTS. BUT EASTERLY WINDS OVER THE NORTHERN PART OF THE LAKE
AND SOUTHERLY WINDS OVER THE SOUTHERN PART OF THE LAKE ARE
EXPECTED AS THE LOW APPROACHES. ONCE IT PASSES...WINDS WILL SHIFT
TO THE NORTHWEST WITH A PERIOD OF 30KTS EXPECTED FRIDAY NIGHT WITH
LOW END GALES POSSIBLE. WINDS MAY DIMINISH A BIT SATURDAY BUT AS
MUCH COLDER AIR SPREADS BACK ACROSS THE REGION SATURDAY NIGHT AND
SUNDAY...WINDS WILL LIKELY INCREASE BACK TO 30 KT OR POSSIBLY LOW
END GALES. FREEZING SPRAY WILL ALSO BE POSSIBLE...SATURDAY NIGHT
THROUGH MONDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1016 AM CST WED JAN 13 2016
.UPDATE...
1015 AM CST
THE GOING FORECAST AND MESSAGE FOR TODAY REMAIN IN GOOD SHAPE
WITH A PERIOD OF LIGHT SNOW FOR A GOOD PORTION OF THE FORECAST
AREA THROUGH MAINLY 3-4 PM. HAVE ONLY MADE SUBTLE ADJUSTMENTS TO
SPECIFIC HOURLY TIMING. FOR IMPACTS...THIS CONTINUES TO LOOK LIKE
MOST OF THE SNOW OUTSIDE OF SOME SPOTTY SNOW SHOWERS TO BE MAINLY
DONE BY 4 PM AND THUS SANDWICHED BETWEEN THE PRIMARY COMMUTES FOR
MANY. OBVIOUSLY LINGERING IMPACTS OF LIGHTLY SNOW COVERED ROADS
MAY RESULT.
LIGHT SNOW WITH 6-9SM VISIBILITY IS BEING OBSERVED ACROSS MOST OF
THE NORTHERN ILLINOIS CWA AS OF 1000 AM WITHIN BROAD WARM
ADVECTION...WITH EVEN LOCAL VISIBILITY AROUND 3SM OUT OUR WINDOW
HERE IN ROMEOVILLE. THE WARM ADVECTION FLOW HAS GRADUALLY BEEN
STRENGTHENING PER THE DVN AND LOT VAD WIND PROFILERS AND THUS THE
ISENTROPIC ASCENT HAS AS WELL. THIS SHOULD FURTHER INCREASE AS THE
PRIMARY SHORT WAVE DISTURBANCE LOCATED OVER SOUTHERN MN PROGRESSES
QUICKLY TOWARD THE AREA. THE RAP ISENTROPIC ANALYSIS CAPTURES WHAT
IS OCCURRING WELL WITH A COMPACT AREA OF ASCENT LINING UP WELL
WITH RADAR...AND ITS THERMAL PROFILES ARE ALSO PRETTY CLOSE TO
RECENT AMDAR DATA. SO CONFIDENCE IN THE RAP AND HRRR SOLUTIONS
REMAIN FAIRLY HIGH AND THUS ONLY MINOR MASSAGING TO THE CURRENT
FORECAST WITH THIS DATA.
THE THERMAL PROFILE ON RECENT AMDAR DATA FROM NEAR MDW INDICATES
THE LOWEST 10,000 FT OF THE SOUNDING LOCATED BETWEEN -10C AND
-15C...CLASSIC OF A COLD AIR MASS. WITH ROOM FOR A LITTLE BIT OF
WET BULB COOLING TO OFFSET THE WARM ADVECTION...THE THERMAL
PROFILE SHOULD LIKELY REMAIN AS SUCH THROUGH THE NEXT SEVERAL HOUR
SNOWFALL...AND THUS ASSIST IN SOME LARGE SNOWFLAKE SIZE AT LEAST
IN THE CLOUD LAYER. SO STILL THINKING A COUPLE TENTHS TO ONE HALF
INCH WITH LOCALIZED ONE INCH AMOUNTS OF FLUFFY SNOW POSSIBLE.
MTF
&&
.SHORT TERM...
353 AM CST
TODAY AND TONIGHT...
FOCUS FOR TODAY IS ON ANOTHER LIGHT(ER) SNOW EVENT DEVELOPING
FROM MID-MORNING THROUGH THIS AFTERNOON.
REGIONAL RADAR MOSAIC DEPICTING SOME WEAK RETURNS ACROSS PORTIONS
OF CENTRAL IOWA AT 09Z...ASSOCIATED WITH ISENTROPIC WARM ADVECTION
ASCENT WITH A MINOR AMPLITUDE SHORT WAVE TROUGH PROPAGATING
SOUTHEAST ACROSS EASTERN NEBRASKA/WESTERN IOWA PER GOES WATER
VAPOR IMAGERY. SUITE OF GUIDANCE INDICATE THIS AREA OF LIGHT SNOW
WILL EXPAND EASTWARD INTO SOUTHERN WI/NORTHERN IL AND NORTHWEST
INDIANA THROUGH MID-DAY...AS ANOTHER FASTER MOVING DISTURBANCE
RIPPLES QUICKLY FROM THE CANADIAN PRAIRIES/NORTHERN PLAINS TO THE
FORECAST AREA THIS AFTERNOON. LATEST WRF-NAM/RAP GUIDANCE
INDICATES MODEST LIFT INTERSECTING ABOUT A 75 MB DEEP DENDRITIC
GROWTH ZONE BETWEEN ROUGHLY 600-700 MB...THOUGH HIGHER RELATIVE
HUMIDITY IS LOCATED BENEATH THIS ZONE AND FORCING IS
WEAKER/SHORTER LIVED THAN WITH THE MUCH STRONGER SYSTEM OF THIS
PAST MONDAY. VARIOUS MODEL QPF/S ARE ONLY A COUPLE OF HUNDREDTHS
OF AN INCH...WITH EXPECTED SNOW/LIQUID RATIOS PERHAPS 16-19:1
YIELDING GENERALLY AN INCH OR LESS. SURFACE TEMPS WILL RISE INTO
THE TEENS/LOW 20S THROUGH THIS AFTERNOON SO SNOW SHOULD HAVE NO
TROUBLE STICKING. THE SECOND QUICK-MOVING MID-LEVEL SHORT WAVE IS
PROGGED TO MOVE EAST OF THE CWA BY THIS EVENING...BRINGING
PRECIPITATION TO AN END. WITH WEAK SURFACE REFLECTION/WARM FRONT
MOVING TO THE EAST-NORTHEAST OF THE AREA TONIGHT...TEMPERATURES
LOOK TO REMAIN NEARLY STEADY FROM LATE DAY HIGHS. READINGS IN THE
20S/HIGH TEENS OVERNIGHT SHOULD BE A WELCOME RESPITE FROM THE
SINGLE DIGITS AND LOCAL SUB-ZERO NUMBERS OF EARLY THIS MORNING.
RATZER
&&
.LONG TERM...
353 AM CST
THURSDAY THROUGH TUESDAY...
MILDER WEATHER...A BRIEF JANUARY THAW...WILL START THE EXTENDED
PERIOD THURSDAY INTO FRIDAY AS UPPER FLOW FLATTENS AHEAD OF AN
UPPER TROUGH WHICH IS CURRENTLY APPROACHING THE PACIFIC COAST.
MODELS HAVE TRENDED FARTHER SOUTH WITH SOUTHERN STREAM ENERGY NOW
TRACKING INTO NORTHERN MEXICO...WITH DOMINANT NORTHERN STREAM
SURFACE LOW PROGGED TO MOVE JUST NORTH OF THE CWA THURSDAY NIGHT.
WITH SOUTH WINDS AND AIR TEMPS HOLDING ABOVE
FREEZING...DRIZZLE/LIGHT RAIN EXPECTED TO DEVELOP LATE THURSDAY
NIGHT AND CONTINUE INTO FRIDAY AS MID-LEVEL WAVE AND SURFACE LOW
PASS. SOME CONCERNS EXIST THAT SNOW COVER AND COLD GROUND MAY KEEP
SURFACE TEMPS NEAR FREEZING THURSDAY NIGHT WHICH COULD RESULT IN
PATCHY FREEZING DRIZZLE...AND THE POTENTIAL FOR FOG INCREASES AS
WELL WITH MOIST ADVECTION FROM THE SOUTH AND DEW POINT TEMPS
CLIMBING ABOVE FREEZING THURSDAY NIGHT/FRIDAY MORNING. THE COLUMN
DOES COOL ENOUGH TO CHANGE PRECIPITATION OVER TO SNOW POST-
FRONTALLY FRIDAY AFTERNOON/NIGHT... THOUGH LITTLE ACCUMULATION
EXPECTED WITH ONLY LIGHT QPF DEPICTED IN THE COLDER AIR.
MEDIUM/LONG RANGE SOLUTIONS CONTINUE TO PULL ARCTIC AIR BACK INTO
THE REGION SATURDAY NIGHT INTO EARLY NEXT WEEK...WITH ANOTHER PUSH
OF -20 DEG 850 MB AIR INDICATED BY BOTH ECMWF/GFS SUNDAY/SUNDAY
NIGHT. SINGLE DIGIT TEMPS ARRIVE SATURDAY NIGHT AND
SUNDAY...LIKELY DIPPING BELOW ZERO IN MANY SPOTS BY MONDAY
MORNING. SURFACE HIGH PRESSURE RIDGE MOVES ACROSS THE REGION
MONDAY/MONDAY NIGHT...THEN FLOW FLATTENS WITH ANOTHER MODERATING
TREND APPEARING TUESDAY INTO MID-NEXT WEEK.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LIGHT SNOW CONTINUING THRU MID AFTERNOON...WITH IFR VIS AND
MVFR CIGS.
* POSSIBLE MVFR OR IFR CIGS OVERNIGHT INTO THURSDAY MORNING.
CMS/BMD
//DISCUSSION...UPDATED 12Z...
AN UPPER WAVE WILL MOVE ACROSS THE AREA LATER THIS MORNING INTO
THIS AFTERNOON WITH A BAND OF LIGHT SNOW THAT WILL LIKELY DEVELOP
RIGHT OVER THE TERMINALS. ONLY CHANGE TO PREVIOUS FORECAST WAS TO
DELAY IFR VIS UNTIL 17Z FOR CHICAGO TERMINALS...BUT TWEAKS TO
TIMING CAN BE EXPECTED AS TRENDS EMERGE LATER THIS MORNING. LIGHT
SNOW WILL LIKELY CONTINUE FOR A 3-5 HOUR PERIOD AND THEN TAPER OFF
TO FLURRIES BY MID/LATE AFTERNOON.
SOUTHWEST WINDS UNDER 10KTS THIS MORNING WILL INCREASE INTO THE
10-15KT RANGE AND GUIDANCE IS NOW SHOWING WINDS MAY BE A BIT
STRONGER ALONG WITH SOME GUSTS INTO THE MID/UPPER TEEN RANGE.
WHILE NOT TOO STRONG...THIS COULD CAUSE SOME BLOWING OR LOW
DRIFTING SNOW.
CIGS WILL LIKELY BECOME VFR BY THIS EVENING BUT WARM AIR ADVECTION
BEGINS OVERNIGHT...OVER THE FRESH SNOW PACK AND ITS POSSIBLE THAT
MVFR OR PERHAPS IFR CIGS MAY DEVELOP BY DAYBREAK THURSDAY. GIVEN
THE UNCERTAINTY ONLY HAVE SCATTERED MENTIONED WITH THIS FORECAST.
CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH FOR SNOW TIMING/DURATION BUT LOW-MEDIUM FOR
VIS/CIGS.
* HIGH FOR WINDS THRU THE PERIOD.
* LOW FOR CIGS OVERNIGHT INTO THURSDAY MORNING. CMS/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT...CHANCE OF RAIN/DRIZZLE. IFR/LIFR LIKELY. SOUTH
WINDS.
* FRIDAY...RAIN CHANGING TO SNOW. IFR LIKELY. SOUTHWEST WINDS
SHIFTING NORTHWEST.
* SATURDAY AND SUNDAY...DRY. MVFR POSSIBLE. GUSTY NORTHWEST WINDS.
* MONDAY...DRY/VFR. NORTHWEST WINDS.
* TUESDAY...DRY. MVFR POSSIBLE. WESTERLY WINDS.
&&
.MARINE...
312 AM...HIGH PRESSURE OVER THE OHIO VALLEY WILL MOVE SOUTHEAST
TODAY AS LOW PRESSURE DEVELOPS OVER LAKE SUPERIOR. THIS WILL
MAINTAIN A WEST/SOUTHWEST WIND IN THE 15-25KT RANGE THROUGH THIS
EVENING. WINDS WILL SLOWLY DIMINISH TONIGHT WITH LIGHT WINDS
EXPECTED OVER NORTHERN PORTIONS OF THE LAKE THURSDAY. SOUTHERLY
WINDS WILL CONTINUE OVER THE SOUTHERN PART OF THE LAKE AS ANOTHER
LOW MOVES ACROSS THE NORTHERN PLAINS THURSDAY AND ACROSS THE
WESTERN LAKES REGION FRIDAY. DUE TO THE TRACK OF THE LOW ACROSS
THE LAKE...CHANGES TO WIND DIRECTIONS CAN BE EXPECTED WITH LATER
FORECASTS. BUT EASTERLY WINDS OVER THE NORTHERN PART OF THE LAKE
AND SOUTHERLY WINDS OVER THE SOUTHERN PART OF THE LAKE ARE
EXPECTED AS THE LOW APPROACHES. ONCE IT PASSES...WINDS WILL SHIFT
TO THE NORTHWEST WITH A PERIOD OF 30KTS EXPECTED FRIDAY NIGHT WITH
LOW END GALES POSSIBLE. WINDS MAY DIMINISH A BIT SATURDAY BUT AS
MUCH COLDER AIR SPREADS BACK ACROSS THE REGION SATURDAY NIGHT AND
SUNDAY...WINDS WILL LIKELY INCREASE BACK TO 30 KT OR POSSIBLY LOW
END GALES. FREEZING SPRAY WILL ALSO BE POSSIBLE...SATURDAY NIGHT
THROUGH MONDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
954 PM EST THU JAN 14 2016
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 245 PM EST THU JAN 14 2016
A COLD FRONT WILL BRING RAIN TO CENTRAL INDIANA FRIDAY...THEN AN
ARCTIC COLD FRONT WILL BRING SOME SNOW ON SUNDAY ALONG WITH MUCH
COLDER AIR. THE FRIGID AIR WILL LAST UNTIL MID WEEK BEFORE
TEMPERATURES MODERATE SOME. SOME LIGHT SNOW IS POSSIBLE TUESDAY
NIGHT AND AGAIN THURSDAY.
&&
.NEAR TERM /OVERNIGHT|/...
ISSUED AT 933 PM EST THU JAN 14 2016
LOW PRESSURE CENTERED OVER IOWA WAS HELPING TO PROVIDE A WARM AND
SOUTHERLY FLOW OF AIR TO CENTRAL INDIANA AS DEW POINTS HAVE SOARED
INTO THE 30S AND TEMPS WERE HOLDING IN THE 40S. SATELLITE SHOWS
SOME MID AND HIGH CLOUD ACROSS TENNESSEE AND KENTUCKY STREAMING
NORTH TOWARD INDIANA.
GFS 290K SURFACE REVEALS GOOD ISENTROPIC LIFT EXPECTED BY 12Z AS A
SURGE OF MOISTURE ARRIVES WITH SPECIFIC HUMIDITIES OVER 5 G/KG.
TIME HEIGHTS AND FORECAST SOUNDINGS ALSO SHOWING GOOD LOWER LEVEL
SATURATION BY 12Z. HRRR SHOWS PRECIP BREAKING OUT TOWARD 12Z
WITHIN THE ISENTROPIC LIFT. BETTER FORCING WILL ARRIVE AFTER 12Z
AS THE SHORT WAVE OVER THE WESTERN PLAINS ARRIVES IN CENTRAL
INDIANA. THUS WILL CONTINUE THE ONGOING FORECAST OVERNIGHT...WITH
INCREASING CLOUDS AND MAINLY A DRY NIGHT...BUT INCHING POPS UPWARD
AFTER 09Z.
AS FOR TEMPS...HAVE RAISED TEMPS ABOUT 2-3 DEGREES DUE TO EXPECTED
INCREASING CLOUDS ALONG WITH ONGOING WARM AIR ADVECTION.
&&
.SHORT TERM.../FRIDAY THROUGH SUNDAY/
ISSUED AT 245 PM EST THU JAN 14 2016
FOCUS IS ON PRECIPITATION CHANCES EARLY AND LATE IN THE PERIOD.
OVERALL...MODELS ARE SIMILAR WITH THE BIG PICTURE. THERE ARE SOME
TIMING DIFFERENCES WITH THE ARCTIC FRONT SATURDAY NIGHT/SUNDAY
MORNING. THAT FAR OUT...DECIDED A BLEND WOULD STILL WORK OUT BEST
GIVEN THE UNCERTAINTY INVOLVED.
ON FRIDAY AN UPPER TROUGH AND COLD FRONT WILL MOVE INTO THE AREA.
850MB WINDS NEAR 50KT...ISENTROPIC LIFT...AND LARGER SCALE DYNAMICS
FROM THE TROUGH WILL WORK TOGETHER TO PRODUCE RAIN ACROSS THE AREA.
WENT LIKELY OR CATEGORICAL POPS ALL AREAS.
RAIN WILL DIMINISH ACROSS THE WEST DURING THE AFTERNOON BEHIND THE
FRONT...AND TEMPERATURES MAY COOL ENOUGH THERE FOR SOME SNOW TO MIX
IN WITH ANY LINGERING RAIN BY LATE FRIDAY AFTERNOON.
UPPER TROUGH AXIS WILL STILL BE CROSSING THE AREA FRIDAY EVENING AND
CYCLONIC FLOW WILL CONTINUE THROUGH THE NIGHT. THIS SHOULD BE ENOUGH
FOR MAINLY SOME SLIGHT CHANCE POPS THROUGH THE PERIOD. TEMPERATURES
WILL BE COLD ENOUGH FOR SNOW AS THE PRECIPITATION TYPE.
ON SATURDAY THE BULK OF THE MOISTURE WILL MOVE OUT OF THE
AREA...REDUCING THE CHANCES FOR SNOW. CANNOT RULE OUT SOME FLURRIES
/OR PERHAPS FREEZING DRIZZLE IF ENOUGH MOISTURE EXITS ALOFT/. WILL
PUT SOME FLURRIES IN FOR NOW.
ARCTIC FRONT APPROACHES SATURDAY NIGHT AND MOVES THROUGH ON SUNDAY.
WENT WITH SOME SLIGHT CHANCE POPS FAR NORTHWEST LATE IN THE NIGHT TO
ACCOUNT FOR THE POTENTIAL OF THE FRONT REACHING THERE BY 12Z.
EXPECT TYPICAL CONDITIONS TO OCCUR ON SUNDAY WHEN AN ARCTIC FRONT
MOVES THROUGH...SO WENT SCATTERED SNOW SHOWERS ALL AREAS. NAM
INDICATES SNOW SQUALL POTENTIAL IN SOME AREAS...AND MODEL TIME
SECTIONS SHOW PERHAPS SOME WEAK INSTABILITY. THUS SOME OF THE SNOW
SHOWERS COULD BE BRIEFLY HEAVY. HOWEVER OVERALL ACCUMULATION LOOKS
TO BE LESS THAN AN INCH.
GENERALLY STAYED WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE
SHORT TERM.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 235 PM EST THU JAN 14 2016
VERY COLD START TO THE LONG TERM PERIOD EXPECTED...WITH LOWS IN THE
SINGLE DIGITS OR COLDER EARLY IN THE WEEK AND HIGHS ONLY IN THE LOW
TO MID TEENS MONDAY. TEMPERATURES SHOULD MODERATE THROUGH THE
REMAINDER OF THE WEEK WITH THE FREEZING MARK POTENTIALLY MAKING IT
BACK TO INDY BY THURSDAY.
REMOVED SOME SLIGHT CHANCE POPS IN PERIODS WHEN NEITHER THE GFS OR
EURO PRODUCED ANY QPF AND UPPER LEVEL SUPPORT WAS MINIMAL OR
NONEXISTENT. BLENDED INITIALIZATION TENDS TO OVERDO LOW POPS SO THIS
IS NOT SURPRISING.
MAY SEE A FEW FLAKES TUESDAY NIGHT AND PERHAPS THURSDAY AS ANOTHER
SYSTEM APPROACHES THE AREA. TEMPERATURES WILL BE MORE BORDERLINE
LATE IN THE WEEK AND SOME MIXED PRECIPITATION CANNOT BE RULED OUT.
&&
.AVIATION /DISCUSSION FOR THE 150300Z KIND TAF UPDATE/...
ISSUED AT 926 PM EST THU JAN 14 2016
NO CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.
STRENGTHENING LOW LEVEL SOUTH SOUTHWESTERLY FLOW TONIGHT SHOULD ALLOW FOR
CEILINGS 040-050 CURRENTLY OVER THE LOWER MISSISSIPPI VALLEY TO ADVECT
OVER THE TERMINALS AFTER 150700Z-150900Z. THE SUSTAINED WARM/MOIST
ADVECTION PATTERN MAY ALLOW FOR CEILINGS TO FALL INTO THE MVFR CATEGORY
TOWARDS DAYBREAK FRIDAY IN THE KHUF/KBMG AREAS.
CONCERN FOR LOW LEVEL WIND SHEAR AFTER 150600Z AROUND 015 AS MODELS
SUGGEST A 40-45KT LOW LEVEL JET WILL MOVE INTO THE AREA...ALONG WITH A
DEVELOPING LOW LEVEL INVERSION. AT THIS TIME...WOULD LIKE TO SEE THE
LOW LEVEL JET A LITTLE STRONGER FOR AN INCLUSION IN THE FORECAST. WILL
LEAVE OUT FOR NOW AND MONITOR THE STRENGTH OF THE LOW LEVEL JET DURING
THE COURSE OF THE EVENING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM...NIELD
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
542 PM EST WED JAN 13 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 231 PM EST WED JAN 13 2016
A LOW PRESSURE SYSTEM WILL BRING RAIN TO THE AREA THURSDAY NIGHT
INTO FRIDAY...ALONG WITH SOME SNOW CHANCES FRIDAY NIGHT. MUCH COLDER
AIR WILL MOVE IN STARTING SATURDAY...AND SOME LIGHT SNOW IS POSSIBLE
INTO SUNDAY AS THE COLD AIR MOVES IN. SOME LIGHT PRECIPITATION IS
POSSIBLE NEXT WEDNESDAY WITH ANOTHER SYSTEM. THE COLDER AIR WILL
MODERATE SOME MID WEEK NEXT WEEK.
&&
.NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/
ISSUED AT 231 PM EST WED JAN 13 2016
AN UPPER WAVE IS GENERATING SOME LIGHT SNOW ACROSS MAINLY THE
NORTHERN THIRD OF THE AREA THIS AFTERNOON...WITH SCATTERED LIGHT
SNOW SHOWERS ACROSS THE REMAINDER OF THE NORTHERN HALF.
THE SNOW WILL MOVE QUICKLY EAST THIS AFTERNOON. HRRR MODEL SHOWING
PERHAPS SOME LINGERING SNOW SHOWERS ACROSS THE FAR NORTHEAST AT
00Z...SO KEPT TOKEN 20 POPS THERE FOR AN HOUR OR TWO. OTHERWISE THE
NIGHT WILL BE DRY WITH A LACK OF FORCING.
HOWEVER...WARM ADVECTION BEGINS...SO TEMPERATURES WILL GRADUALLY
WARM OVERNIGHT. LOW TEMPERATURES WILL THUS LIKELY OCCUR NEAR 00Z.
WITH THE WARM ADVECTION ALOFT EXPECT SOME MID AND HIGH CLOUDS AT
TIMES DURING THE NIGHT. SOME CONCERN ABOUT LOW CLOUDS DEVELOPING
LATER TONIGHT AS DEWPOINTS RISE...BUT AM NOT CONFIDENT ENOUGH TO
INCLUDE AT THIS TIME.
&&
.SHORT TERM.../THURSDAY THROUGH SATURDAY/
ISSUED AT 231 PM EST WED JAN 13 2016
FOCUS IS ON CHANCES FOR PRECIPITATION. OVERALL MODELS ARE CLOSE
ENOUGH THAT A BLEND WAS USED.
WARM ADVECTION CONTINUES ON THURSDAY...BUT NOT ENOUGH FORCING OR
MOISTURE AROUND FOR ANY PRECIPITATION. WENT A LITTLE COOLER THAN MOS
FOR HIGH TEMPERATURES GIVEN THE SNOW COVER AND COLD GROUND.
ISENTROPIC LIFT INCREASES THURSDAY NIGHT AHEAD OF AN APPROACHING
SYSTEM...BUT FORCING/MOISTURE REMAIN RELATIVELY LIMITED. WILL ONLY
GO SLIGHT CHANCE POPS...WITH MOST COVERAGE DURING THE LATE NIGHT.
ON FRIDAY...LOW PRESSURE FROM A NORTHERN STREAM SYSTEM WILL MOVE
INTO THE GREAT LAKES AND BRING A COLD FRONT INTO OUR AREA. A
SOUTHERN STREAM SYSTEM WILL REMAIN WELL TO THE SOUTHEAST OF THE
AREA.
SOME OF THE MOISTURE FROM THE SOUTHERN STREAM MAY MAKE IT INTO THE
AREA...BUT THE BULK OF IT WILL REMAIN SOUTHEAST. HOWEVER THE
NORTHERN SYSTEM WILL STILL HAVE ENOUGH MOISTURE TO WORK WITH TO GO
LIKELY POPS ALL AREAS.
THE FRONT WILL MOVE THROUGH THE AREA DURING THE DAY...TAKING THE
MOISTURE WITH IT. THUS ONLY EXPECT CHANCE POPS FRIDAY NIGHT. COLDER
AIR WILL HAVE MOVED IN...SO WENT MAINLY SNOW MOST AREAS FRIDAY
NIGHT. WITH LIMITED MOISTURE AVAILABLE...DO NOT EXPECT MUCH IF ANY
SNOW ACCUMULATION.
ON SATURDAY COLD ADVECTION WILL CONTINUE...AND THERE COULD BE A WEAK
SURFACE TROUGH IN THE AREA AS WELL. THUS FEEL THAT SLIGHT CHANCE
POPS FOR SNOW SHOWERS STILL LOOK GOOD FOR MOST OF THE AREA.
GENERALLY STAYED WITH A MODEL BLEND FOR TEMPERATURES THURSDAY NIGHT
INTO SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 151 PM EST WED JAN 13 2016
FOCUS LATE THIS WEEKEND AND EARLY NEXT WEEK WILL BE ON TEMPERATURES
AS AN ARCTIC AIRMASS IS EXPECTED TO INVADE THE LOWER GREAT LAKES AND
OHIO VALLEY FROM WESTERN CANADA. MEANWHILE...TEMPERATURE RECOVERY
AND PRECIPITATION CHANCES WILL BE THE TALKING POINTS BY WEDNESDAY
AS LOW LEVEL FLOW BECOMES SOUTHERLY AND UPPER FLOW MORE ZONAL.
THE OPERATIONAL MODELS HAVE BEEN INCONSISTENT WITH SYNOPTIC FEATURES
MODEL TO MODEL AND RUN TO RUN. SO...ENSEMBLE MEAN BLEND APPROACH PER
THE REGIONAL BLEND LOOKS GOOD. BLEND WILL START OFF WITH A COLD
UPPER LOW NEAR WESTERN LAKE SUPERIOR AND AN UPPER TROUGH NEAR
EASTERN TEXAS. AT THE SURFACE...ARCTIC AIR WILL BE FILTERING IN FROM
WESTERN CANADA. DECENT FORCING FROM GREAT LAKES UPPER LOW BUT
MARGINAL MOISTURE SUPPORTS SMALL SNOW CHANCES PER THE REGIONAL BLEND
THROUGH SUNDAY. THEN...AS THE UPPER LOW MOVES INTO QUEBEC AND THE
ARCTIC AIR BUILDS IN...DRY WEATHER IS EXPECTED THROUGH TUESDAY
NIGHT. UPPER FLOW WILL BE MORE ZONAL TOWARD WEDNESDAY WHICH COULD
BRING A SURFACE FRONT CLOSE ENOUGH FOR SOME SHOWERS BY WEDNESDAY.
BIG DIFFERENCES IN OPERATIONAL GFS AND ECMWF 850 MILLIBAR AND
SURFACE TEMPERATURES. THE ECWMF IS SOME 5 DEGREES OR SO COLDER AT
12Z SUNDAY WITH 15 DEGREES BELOW ZERO CELSIUS ACROSS OUR SOUTHEAST
AND 21 DEGREES CELSIUS BELOW ACROSS OUR NORTHWEST. MEANWHILE...THE
COLDEST AIR OF THE WEEKEND WILL BE OVER THE AREA SUNDAY AFTERNOON
WITH 850 MILLIBAR TEMPERATURES AS COLD AS 28 DEGREES BELOW. WITH
SOME CLEARING POSSIBLE SUNDAY NIGHT...BELOW ZERO OVERNIGHT LOWS
CERTAINLY LOOK POSSIBLE...ESPECIALLY IF THERE IS ANY SNOW ON THE
GROUND. AFTER SUNDAY NIGHT...TEMPERATURES WILL START REBOUNDING. THE
ECMWF IS QUICKER TO BRING THE MORE MILD AIR IN FROM THE GULF AS THE
ARCTIC HIGH SHIFTS TO THE EAST NEXT MONDAY NIGHT INTO TUESDAY. WITH
CONFIDENCE LOW ON TEMPERATURES...BEING DAYS 6 AND 7 AND WITH MODEL
INCONSISTENCIES...WILL ACCEPT THE REGIONAL BLEND WHICH SUGGESTS NEAR
AND ABOVE FREEZING TEMPERATURES ARE POSSIBLE BY WEDNESDAY. THIS ALSO
HINTS SOUTHERN AREAS OF THE FORECAST AREA COULD SEE A MIX AT THAT
TIME WITH MOSTLY SNOW NORTH.
&&
.AVIATION /DISCUSSION FOR THE 140000Z TAFS/...
ISSUED AT 542 PM EST WED JAN 13 2016
AREA OF SCT-BKN CLOUDS NEAR 040 CURRENTLY OVER NORTHERN ILLINOIS EXPECTED
TO PUSH OVER THE TERMINALS FOR A PERIOD THIS EVENING. BEST CHANCE FOR
A CEILING NEAR THIS LEVEL WILL BE AT KLAF. SHORT TERM MODELS INDICATE DRYING
NEAR THIS LEVEL LATER TONIGHT...SO THESE CLOUDS SHOULD DISSIPATE PRIOR TO
140600Z.
LINGERING SURFACE WIND GUSTS EXPECTED TO DIMINISH WITH SUNSET. AFTER
SUNSET SURFACE WINDS 200-230 DEGREES AT 5-10 KTS.
NO VISIBILITY RESTRICTIONS EXPECTED TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
344 PM EST WED JAN 13 2016
.UPDATE...
AVIATION SECTION UPDATED
&&
.SYNOPSIS...
ISSUED AT 231 PM EST WED JAN 13 2016
A LOW PRESSURE SYSTEM WILL BRING RAIN TO THE AREA THURSDAY NIGHT
INTO FRIDAY...ALONG WITH SOME SNOW CHANCES FRIDAY NIGHT. MUCH COLDER
AIR WILL MOVE IN STARTING SATURDAY...AND SOME LIGHT SNOW IS POSSIBLE
INTO SUNDAY AS THE COLD AIR MOVES IN. SOME LIGHT PRECIPITATION IS
POSSIBLE NEXT WEDNESDAY WITH ANOTHER SYSTEM. THE COLDER AIR WILL
MODERATE SOME MID WEEK NEXT WEEK.
&&
.NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/
ISSUED AT 231 PM EST WED JAN 13 2016
AN UPPER WAVE IS GENERATING SOME LIGHT SNOW ACROSS MAINLY THE
NORTHERN THIRD OF THE AREA THIS AFTERNOON...WITH SCATTERED LIGHT
SNOW SHOWERS ACROSS THE REMAINDER OF THE NORTHERN HALF.
THE SNOW WILL MOVE QUICKLY EAST THIS AFTERNOON. HRRR MODEL SHOWING
PERHAPS SOME LINGERING SNOW SHOWERS ACROSS THE FAR NORTHEAST AT
00Z...SO KEPT TOKEN 20 POPS THERE FOR AN HOUR OR TWO. OTHERWISE THE
NIGHT WILL BE DRY WITH A LACK OF FORCING.
HOWEVER...WARM ADVECTION BEGINS...SO TEMPERATURES WILL GRADUALLY
WARM OVERNIGHT. LOW TEMPERATURES WILL THUS LIKELY OCCUR NEAR 00Z.
WITH THE WARM ADVECTION ALOFT EXPECT SOME MID AND HIGH CLOUDS AT
TIMES DURING THE NIGHT. SOME CONCERN ABOUT LOW CLOUDS DEVELOPING
LATER TONIGHT AS DEWPOINTS RISE...BUT AM NOT CONFIDENT ENOUGH TO
INCLUDE AT THIS TIME.
&&
.SHORT TERM.../THURSDAY THROUGH SATURDAY/
ISSUED AT 231 PM EST WED JAN 13 2016
FOCUS IS ON CHANCES FOR PRECIPITATION. OVERALL MODELS ARE CLOSE
ENOUGH THAT A BLEND WAS USED.
WARM ADVECTION CONTINUES ON THURSDAY...BUT NOT ENOUGH FORCING OR
MOISTURE AROUND FOR ANY PRECIPITATION. WENT A LITTLE COOLER THAN MOS
FOR HIGH TEMPERATURES GIVEN THE SNOW COVER AND COLD GROUND.
ISENTROPIC LIFT INCREASES THURSDAY NIGHT AHEAD OF AN APPROACHING
SYSTEM...BUT FORCING/MOISTURE REMAIN RELATIVELY LIMITED. WILL ONLY
GO SLIGHT CHANCE POPS...WITH MOST COVERAGE DURING THE LATE NIGHT.
ON FRIDAY...LOW PRESSURE FROM A NORTHERN STREAM SYSTEM WILL MOVE
INTO THE GREAT LAKES AND BRING A COLD FRONT INTO OUR AREA. A
SOUTHERN STREAM SYSTEM WILL REMAIN WELL TO THE SOUTHEAST OF THE
AREA.
SOME OF THE MOISTURE FROM THE SOUTHERN STREAM MAY MAKE IT INTO THE
AREA...BUT THE BULK OF IT WILL REMAIN SOUTHEAST. HOWEVER THE
NORTHERN SYSTEM WILL STILL HAVE ENOUGH MOISTURE TO WORK WITH TO GO
LIKELY POPS ALL AREAS.
THE FRONT WILL MOVE THROUGH THE AREA DURING THE DAY...TAKING THE
MOISTURE WITH IT. THUS ONLY EXPECT CHANCE POPS FRIDAY NIGHT. COLDER
AIR WILL HAVE MOVED IN...SO WENT MAINLY SNOW MOST AREAS FRIDAY
NIGHT. WITH LIMITED MOISTURE AVAILABLE...DO NOT EXPECT MUCH IF ANY
SNOW ACCUMULATION.
ON SATURDAY COLD ADVECTION WILL CONTINUE...AND THERE COULD BE A WEAK
SURFACE TROUGH IN THE AREA AS WELL. THUS FEEL THAT SLIGHT CHANCE
POPS FOR SNOW SHOWERS STILL LOOK GOOD FOR MOST OF THE AREA.
GENERALLY STAYED WITH A MODEL BLEND FOR TEMPERATURES THURSDAY NIGHT
INTO SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 151 PM EST WED JAN 13 2016
FOCUS LATE THIS WEEKEND AND EARLY NEXT WEEK WILL BE ON TEMPERATURES
AS AN ARCTIC AIRMASS IS EXPECTED TO INVADE THE LOWER GREAT LAKES AND
OHIO VALLEY FROM WESTERN CANADA. MEANWHILE...TEMPERATURE RECOVERY
AND PRECIPITATION CHANCES WILL BE THE TALKING POINTS BY WEDNESDAY
AS LOW LEVEL FLOW BECOMES SOUTHERLY AND UPPER FLOW MORE ZONAL.
THE OPERATIONAL MODELS HAVE BEEN INCONSISTENT WITH SYNOPTIC FEATURES
MODEL TO MODEL AND RUN TO RUN. SO...ENSEMBLE MEAN BLEND APPROACH PER
THE REGIONAL BLEND LOOKS GOOD. BLEND WILL START OFF WITH A COLD
UPPER LOW NEAR WESTERN LAKE SUPERIOR AND AN UPPER TROUGH NEAR
EASTERN TEXAS. AT THE SURFACE...ARCTIC AIR WILL BE FILTERING IN FROM
WESTERN CANADA. DECENT FORCING FROM GREAT LAKES UPPER LOW BUT
MARGINAL MOISTURE SUPPORTS SMALL SNOW CHANCES PER THE REGIONAL BLEND
THROUGH SUNDAY. THEN...AS THE UPPER LOW MOVES INTO QUEBEC AND THE
ARCTIC AIR BUILDS IN...DRY WEATHER IS EXPECTED THROUGH TUESDAY
NIGHT. UPPER FLOW WILL BE MORE ZONAL TOWARD WEDNESDAY WHICH COULD
BRING A SURFACE FRONT CLOSE ENOUGH FOR SOME SHOWERS BY WEDNESDAY.
BIG DIFFERENCES IN OPERATIONAL GFS AND ECMWF 850 MILLIBAR AND
SURFACE TEMPERATURES. THE ECWMF IS SOME 5 DEGREES OR SO COLDER AT
12Z SUNDAY WITH 15 DEGREES BELOW ZERO CELSIUS ACROSS OUR SOUTHEAST
AND 21 DEGREES CELSIUS BELOW ACROSS OUR NORTHWEST. MEANWHILE...THE
COLDEST AIR OF THE WEEKEND WILL BE OVER THE AREA SUNDAY AFTERNOON
WITH 850 MILLIBAR TEMPERATURES AS COLD AS 28 DEGREES BELOW. WITH
SOME CLEARING POSSIBLE SUNDAY NIGHT...BELOW ZERO OVERNIGHT LOWS
CERTAINLY LOOK POSSIBLE...ESPECIALLY IF THERE IS ANY SNOW ON THE
GROUND. AFTER SUNDAY NIGHT...TEMPERATURES WILL START REBOUNDING. THE
ECMWF IS QUICKER TO BRING THE MORE MILD AIR IN FROM THE GULF AS THE
ARCTIC HIGH SHIFTS TO THE EAST NEXT MONDAY NIGHT INTO TUESDAY. WITH
CONFIDENCE LOW ON TEMPERATURES...BEING DAYS 6 AND 7 AND WITH MODEL
INCONSISTENCIES...WILL ACCEPT THE REGIONAL BLEND WHICH SUGGESTS NEAR
AND ABOVE FREEZING TEMPERATURES ARE POSSIBLE BY WEDNESDAY. THIS ALSO
HINTS SOUTHERN AREAS OF THE FORECAST AREA COULD SEE A MIX AT THAT
TIME WITH MOSTLY SNOW NORTH.
&&
.AVIATION /DISCUSSION FOR THE 132100Z IND TAF UPDATE/...
RADAR TRENDS SHOW SHORT WAVE OVER NRN INDIANA AND LOWER MICHIGAN
EXITING THE AREA...AND REMAINING TO THE NORTH OF CENTRAL INDIANA.
FURTHERMORE SATELLITE SHOWS A FEW BREAKS IN THE OVERCAST UPSTREAM
ACROSS WESTERN INDIANA AND EASTERN ILLINOIS. THUS WILL CONTINUE
THE VFR CONDITIONS...REMOVING THE SNOW SHOWER MENTION AND TREND
TOWARD HIGHER CIGS BY 00Z.
PREVIOUS DISCUSSION BELOW
/DISCUSSION FOR 131800Z TAF ISSUANCE/...
ISSUED AT 1124 AM EST WED JAN 13 2016
MOSTLY VFR CONDITIONS THROUGH THE TAF PERIOD. HOWEVER...SNOW SHOWERS
COULD REDUCE CONDITIONS TO MVFR OR POSSIBLY BRIEF IFR...AT LAF
THROUGH 23Z.
AFTER 00Z TONIGHT THROUGH 18Z THURSDAY...EXPECT JUST SOME HIGH
CLOUDS AHEAD OF AN APPROACHING UPPER HIGH PLAINS RIDGE.
SOUTHWEST WINDS 8 TO 12 KNOTS THIS AFTERNOON WILL DROP OFF JUST A
LITTLE BIT OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...MK/JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
231 PM EST WED JAN 13 2016
.UPDATE...
THE SYNOPSIS...NEAR TERM...AND SHORT TERM SECTIONS HAVE BEEN
UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 231 PM EST WED JAN 13 2016
A LOW PRESSURE SYSTEM WILL BRING RAIN TO THE AREA THURSDAY NIGHT
INTO FRIDAY...ALONG WITH SOME SNOW CHANCES FRIDAY NIGHT. MUCH COLDER
AIR WILL MOVE IN STARTING SATURDAY...AND SOME LIGHT SNOW IS POSSIBLE
INTO SUNDAY AS THE COLD AIR MOVES IN. SOME LIGHT PRECIPITATION IS
POSSIBLE NEXT WEDNESDAY WITH ANOTHER SYSTEM. THE COLDER AIR WILL
MODERATE SOME MID WEEK NEXT WEEK.
&&
.NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/
ISSUED AT 231 PM EST WED JAN 13 2016
AN UPPER WAVE IS GENERATING SOME LIGHT SNOW ACROSS MAINLY THE
NORTHERN THIRD OF THE AREA THIS AFTERNOON...WITH SCATTERED LIGHT
SNOW SHOWERS ACROSS THE REMAINDER OF THE NORTHERN HALF.
THE SNOW WILL MOVE QUICKLY EAST THIS AFTERNOON. HRRR MODEL SHOWING
PERHAPS SOME LINGERING SNOW SHOWERS ACROSS THE FAR NORTHEAST AT
00Z...SO KEPT TOKEN 20 POPS THERE FOR AN HOUR OR TWO. OTHERWISE THE
NIGHT WILL BE DRY WITH A LACK OF FORCING.
HOWEVER...WARM ADVECTION BEGINS...SO TEMPERATURES WILL GRADUALLY
WARM OVERNIGHT. LOW TEMPERATURES WILL THUS LIKELY OCCUR NEAR 00Z.
WITH THE WARM ADVECTION ALOFT EXPECT SOME MID AND HIGH CLOUDS AT
TIMES DURING THE NIGHT. SOME CONCERN ABOUT LOW CLOUDS DEVELOPING
LATER TONIGHT AS DEWPOINTS RISE...BUT AM NOT CONFIDENT ENOUGH TO
INCLUDE AT THIS TIME.
&&
.SHORT TERM.../THURSDAY THROUGH SATURDAY/
ISSUED AT 231 PM EST WED JAN 13 2016
FOCUS IS ON CHANCES FOR PRECIPITATION. OVERALL MODELS ARE CLOSE
ENOUGH THAT A BLEND WAS USED.
WARM ADVECTION CONTINUES ON THURSDAY...BUT NOT ENOUGH FORCING OR
MOISTURE AROUND FOR ANY PRECIPITATION. WENT A LITTLE COOLER THAN MOS
FOR HIGH TEMPERATURES GIVEN THE SNOW COVER AND COLD GROUND.
ISENTROPIC LIFT INCREASES THURSDAY NIGHT AHEAD OF AN APPROACHING
SYSTEM...BUT FORCING/MOISTURE REMAIN RELATIVELY LIMITED. WILL ONLY
GO SLIGHT CHANCE POPS...WITH MOST COVERAGE DURING THE LATE NIGHT.
ON FRIDAY...LOW PRESSURE FROM A NORTHERN STREAM SYSTEM WILL MOVE
INTO THE GREAT LAKES AND BRING A COLD FRONT INTO OUR AREA. A
SOUTHERN STREAM SYSTEM WILL REMAIN WELL TO THE SOUTHEAST OF THE
AREA.
SOME OF THE MOISTURE FROM THE SOUTHERN STREAM MAY MAKE IT INTO THE
AREA...BUT THE BULK OF IT WILL REMAIN SOUTHEAST. HOWEVER THE
NORTHERN SYSTEM WILL STILL HAVE ENOUGH MOISTURE TO WORK WITH TO GO
LIKELY POPS ALL AREAS.
THE FRONT WILL MOVE THROUGH THE AREA DURING THE DAY...TAKING THE
MOISTURE WITH IT. THUS ONLY EXPECT CHANCE POPS FRIDAY NIGHT. COLDER
AIR WILL HAVE MOVED IN...SO WENT MAINLY SNOW MOST AREAS FRIDAY
NIGHT. WITH LIMITED MOISTURE AVAILABLE...DO NOT EXPECT MUCH IF ANY
SNOW ACCUMULATION.
ON SATURDAY COLD ADVECTION WILL CONTINUE...AND THERE COULD BE A WEAK
SURFACE TROUGH IN THE AREA AS WELL. THUS FEEL THAT SLIGHT CHANCE
POPS FOR SNOW SHOWERS STILL LOOK GOOD FOR MOST OF THE AREA.
GENERALLY STAYED WITH A MODEL BLEND FOR TEMPERATURES THURSDAY NIGHT
INTO SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 151 PM EST WED JAN 13 2016
FOCUS LATE THIS WEEKEND AND EARLY NEXT WEEK WILL BE ON TEMPERATURES
AS AN ARCTIC AIRMASS IS EXPECTED TO INVADE THE LOWER GREAT LAKES AND
OHIO VALLEY FROM WESTERN CANADA. MEANWHILE...TEMPERATURE RECOVERY
AND PRECIPITATION CHANCES WILL BE THE TALKING POINTS BY WEDNESDAY
AS LOW LEVEL FLOW BECOMES SOUTHERLY AND UPPER FLOW MORE ZONAL.
THE OPERATIONAL MODELS HAVE BEEN INCONSISTENT WITH SYNOPTIC FEATURES
MODEL TO MODEL AND RUN TO RUN. SO...ENSEMBLE MEAN BLEND APPROACH PER
THE REGIONAL BLEND LOOKS GOOD. BLEND WILL START OFF WITH A COLD
UPPER LOW NEAR WESTERN LAKE SUPERIOR AND AN UPPER TROUGH NEAR
EASTERN TEXAS. AT THE SURFACE...ARCTIC AIR WILL BE FILTERING IN FROM
WESTERN CANADA. DECENT FORCING FROM GREAT LAKES UPPER LOW BUT
MARGINAL MOISTURE SUPPORTS SMALL SNOW CHANCES PER THE REGIONAL BLEND
THROUGH SUNDAY. THEN...AS THE UPPER LOW MOVES INTO QUEBEC AND THE
ARCTIC AIR BUILDS IN...DRY WEATHER IS EXPECTED THROUGH TUESDAY
NIGHT. UPPER FLOW WILL BE MORE ZONAL TOWARD WEDNESDAY WHICH COULD
BRING A SURFACE FRONT CLOSE ENOUGH FOR SOME SHOWERS BY WEDNESDAY.
BIG DIFFERENCES IN OPERATIONAL GFS AND ECMWF 850 MILLIBAR AND
SURFACE TEMPERATURES. THE ECWMF IS SOME 5 DEGREES OR SO COLDER AT
12Z SUNDAY WITH 15 DEGREES BELOW ZERO CELSIUS ACROSS OUR SOUTHEAST
AND 21 DEGREES CELSIUS BELOW ACROSS OUR NORTHWEST. MEANWHILE...THE
COLDEST AIR OF THE WEEKEND WILL BE OVER THE AREA SUNDAY AFTERNOON
WITH 850 MILLIBAR TEMPERATURES AS COLD AS 28 DEGREES BELOW. WITH
SOME CLEARING POSSIBLE SUNDAY NIGHT...BELOW ZERO OVERNIGHT LOWS
CERTAINLY LOOK POSSIBLE...ESPECIALLY IF THERE IS ANY SNOW ON THE
GROUND. AFTER SUNDAY NIGHT...TEMPERATURES WILL START REBOUNDING. THE
ECMWF IS QUICKER TO BRING THE MORE MILD AIR IN FROM THE GULF AS THE
ARCTIC HIGH SHIFTS TO THE EAST NEXT MONDAY NIGHT INTO TUESDAY. WITH
CONFIDENCE LOW ON TEMPERATURES...BEING DAYS 6 AND 7 AND WITH MODEL
INCONSISTENCIES...WILL ACCEPT THE REGIONAL BLEND WHICH SUGGESTS NEAR
AND ABOVE FREEZING TEMPERATURES ARE POSSIBLE BY WEDNESDAY. THIS ALSO
HINTS SOUTHERN AREAS OF THE FORECAST AREA COULD SEE A MIX AT THAT
TIME WITH MOSTLY SNOW NORTH.
&&
.AVIATION /DISCUSSION FOR 131800Z TAF ISSUANCE/...
ISSUED AT 1124 AM EST WED JAN 13 2016
MOSTLY VFR CONDITIONS THROUGH THE TAF PERIOD. HOWEVER...SNOW SHOWERS
COULD REDUCE CONDITIONS TO MVFR OR POSSIBLY BRIEF IFR...AT LAF
THROUGH 23Z.
AFTER 00Z TONIGHT THROUGH 18Z THURSDAY...EXPECT JUST SOME HIGH
CLOUDS AHEAD OF AN APPROACHING UPPER HIGH PLAINS RIDGE.
SOUTHWEST WINDS 8 TO 12 KNOTS THIS AFTERNOON WILL DROP OFF JUST A
LITTLE BIT OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....MK
AVIATION...MK
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
523 PM CST THU JAN 14 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Friday)
Issued at 219 PM CST THU JAN 14 2016
At 2 PM, A cold front extended from near Salina to just west of
Marysville. This afternoon, this front was really just an
organized wind shift as temperatures in its wake remained quite
warm in the mid to upper 50s. This was mainly due to deeper post-
frontal boundary layer mixing and a bit of a lag to the cold
advection behind the surface front. Low level moisture along the
front is currently lacking, but as the frontal forcing moves into
areas southeast of Burlington and Ottawa, it will begin to
interact with better moisture and shallow instability up to 100
J/kg. This will likely be sufficient to produce bands of shallow
convective showers. These will develop in the far southeast corner
of the forecast area...or perhaps even just southeast of Anderson
county, most likely between 8-10 PM, and will be light.
The cold air will eventually advect into the area overnight into
Friday with more seasonable temperatures by Friday as highs will
range from the low 30s in far northeast KS to the upper 30s from
Minneapolis to Emporia. There will not be much of a diurnal swing
on Friday given a warm start and continued cold advection...not to
mention an influx of low stratus across a good portion of the area
that may not erode until mid/late afternoon. These clouds pose a
chance for the forecast to err on the warm side as it currently
stands.
.LONG TERM...(Friday Night through Thursday)
Issued at 219 PM CST THU JAN 14 2016
The period through at least next Tuesday will be dominated by the
continuation of northwesterly flow aloft. This will feature
frequent fast moving disturbances of Pacific Northwest and Alberta
Canada origin. Generally speaking, these disturbances will be
moisture starved and not particularly strong...at least the
systems that move over the local forecast area. All of that said,
there are small chances for precipitation as well as a very cold
period.
The big cold push will come Saturday night into Sunday as an
extremely cold airmass from a source region of north central
Canada is pulled through the Dakotas and then into the Ohio
Valley. The local area will not receive the full effect of this
airmass, but the combination of wind and cold will likely bring
wind chills into the -10 to -20 range for parts of the area, and
on Sunday the wind chill may struggle to top the freezing mark.
The upside of the glancing blow of the airmass is that the
recovery should be fairly quick with temperatures in the upper 20s
by Monday and mid 30s by Tuesday.
This system will also bring one of the chances for light snow to
the region, with the best chance being across northeastern
portions of the state. A combination of frontogenesis across a
nice low/mid level temperature gradient, good low/mid level
saturation, and CSI/CI suggests a band of snow will develop and
move across the region. The presence of the CSI/CI along
especially along the southwest flank of this area of lift and
strong surface winds suggests a bit of a snow squall potential
although precipitation/snow amounts should be generally light.
A similar system looks on track to impact the region Monday night
into Tuesday. There is some uncertainty in the timing and
location, but general consensus on the existing of the fast-moving
system with another band of snow. The GFS is quite aggressive with
QPF in this system compared to other model guidance and also has
precip across the entire forecast area while others remain more
focused in northeast KS with a sharper defined band. Have
increased PoPs a bit and at least included a slight chance across
the entire forecast area, with at least some potential for minor
snow accumulation.
By the second half of next week, a potentially stronger system
will cross the Plains. Model guidance has a huge spread in the
possible solutions with this system, and the spread is likely
attributable to multiple vorticity maxima attempting to come on
the west coast in a similar time frame and interact with each
other. For now, a wide range of possibilities is out there
regarding this period of the forecast but there at least appears
to be a good chance for precipitation by Thursday. Have kept the
forecast with rain or snow wording as both are currently possible
depending on the evolution of the storm system.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 523 PM CST THU JAN 14 2016
A cold front will move through the terminals this evening,
shifting the winds to the northwest around 10 kts, timing around
02Z at MHK and between 04Z and 05Z at TOP and FOE. Timing of mvfr
cigs around 11Z-12Z per RUC soundings, then becoming VFR in the
17Z-19Z time period. Winds increase from the northwest around
14kts with gusts to 23kts around 12Z then decrease near the end
of the period.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barjenbruch
LONG TERM...Barjenbruch
AVIATION...53
AREA FORECAST DISCUSSION
NWS JACKSON KY
1006 AM EST WED JAN 13 2016
.UPDATE...
ISSUED AT 1006 AM EST WED JAN 13 2016
BLENDED MORNING OBS INTO THE FORECAST GRIDS AND UPDATED SKY
CONDITIONS THROUGH THIS EVENING BASED ON LATEST MODEL DATA.
HOWEVER...THERE ARE NO SUBSTANTIAL CHANGES TO THE FORECAST.
UPDATE ISSUED AT 750 AM EST WED JAN 13 2016
DID A QUICK UPDATE MAINLY TO FINE TUNE THE TD AND T GRIDS PER THE
LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EST WED JAN 13 2016
07Z SFC ANALYSIS SHOWS COLD HIGH PRESSURE BUILDING INTO KENTUCKY.
THIS IS HELPING TO SETTLE THE WINDS AND HAS CLEARED THE SKY. AS A
RESULT...TEMPERATURES ARE DROPPING TOWARD 10 DEGREES IN THE
EASTERN VALLEYS AND NORTHWEST PARTS OF THE AREA WHILE MID AND
UPPER TEENS ARE FOUND ON THE RIDGES AND THROUGH THE CUMBERLAND
VALLEY. DEW POINTS...MEANWHILE ARE IN THE SINGLE DIGITS MOST
PLACES. THE SNOW SQUALLS OF TUESDAY AFTERNOON SPARED MOST
LOCATIONS GENERALLY SOUTH OF THE MOUNTAIN PARKWAY BUT DID MANAGE
TO LAY DOWN A LAYER OF SNOW OF VARYING THICKNESS NORTH OF THE
HIGHWAY...AND PARTICULARLY FOR POINTS ALONG AND NORTH OF
INTERSTATE 64. THESE PLACES WILL RADIATE EXTRA WELL FOR THE REST
OF THE NIGHT WITH SOME SINGLE DIGITS CERTAINLY POSSIBLE BY DAWN.
WILL LIKELY DO SOME FINAL ADJUSTMENTS TEMPS IN THESE PLACES
BEFORE GRID ISSUANCE.
THE MODELS ARE IN EXCELLENT AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST. THEY ALL DEPICT A CLUSTER OF WEAK
MID LEVEL WAVES PASSING THROUGH THE OHIO VALLEY TODAY AND TONIGHT
IN NORTHWEST FLOW...EVEN AS THE HEIGHTS CONTINUE TO REBOUND.
EASTERN KENTUCKY WILL GET INTO SOME SLIGHT RIDGING ON THURSDAY
AHEAD OF A STILL UNCONSOLIDATED TROUGH MOVING INTO THE CENTRAL
PLAINS AND ANOTHER WEAK ONE LIFTING NORTHEAST FROM NORTHERN
MEXICO IN THE SOUTHERN STREAM. LOOK FOR THESE TO START TO INTERACT
AND BRING A CHANCE OF RAIN TO THE AREA EARLY IN THE EXTENDED. IN
THE MEANTIME...THOUGH...A QUIET MID LEVELS AND DRY AIR IN PLACE
WILL KEEP THE WEATHER RATHER BENIGN THROUGH THURSDAY. HAVE FAVORED
THE HIGHER RESOLUTION GUIDANCE FROM THE HRRR AND NAM12 FOR
FORECAST DETAILS.
SENSIBLE WEATHER WILL FEATURE A CHILLY START WITH TEMPERATURES IN
THE TEENS AND SINGLE DIGITS THIS MORNING ALONG WITH WIND CHILLS
NEAR ZERO AT TIMES. HOWEVER...PLENTY OF SUNSHINE IN THE MORNING
WILL HELP THE MERCURY REBOUND TO ABOVE FREEZING AND INTO THE MID
30S DURING THE AFTERNOON...FOR MOST PLACES WITHOUT A SNOW PACK.
LOCATIONS ALONG AND NORTH OF INTERSTATE 64 WILL STRUGGLE TO SEE
FREEZING TEMPS...THOUGH. A PASSING AREA OF LOW PRESSURE TO THE
NORTH WILL BRING SOME MID LEVEL CLOUDS TO THE NORTHERN PARTS OF
THE CWA THIS AFTERNOON AND EVENING BUT NO PCPN OR FLURRIES ARE
EXPECTED FROM THESE. MILDER TEMPERATURES ARE ON TAP FOR TONIGHT AS
WARMER AIR STARTS TO MOVE IN AND THE HIGH RETREATS TO THE EAST.
THE WARM-UP WILL BE MOST PRONOUNCED ON THURSDAY WHEN SOUTHWEST
WINDS KICK IN SUPPORTING TEMPERATURES TOPPING OUT IN THE UPPER 40S
AND LOWER 50S.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR TEMPS AND
DEW POINTS THROUGH THE EVENING FOLLOWED BY THE SUPERBLEND. DID
MAKE SOME ADJUSTMENTS TONIGHT TO HIGHLIGHT A DECENT RIDGE TO
VALLEY TEMPERATURE SPLIT. AS FOR POPS...THEY ARE BASICALLY LOW
SINGLE DIGITS OR NEAR ZERO THROUGH THE SHORT TERM...IN LINE WITH
MOS GUIDANCE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 335 AM EST WED JAN 13 2016
BIG STORY TO BEGIN THIS PERIOD WILL BE THE CONTINUED ABOVE AVERAGE
TEMPERATURES. WE BEGIN THE PERIOD WITH SURFACE HIGH PARKED TO OUR
SOUTHEAST AND IN THE WARM SECTOR. THIS WILL BE AHEAD OF DEEPENING
UPPER LEVEL TROUGH ACROSS THE NORTHERN CENTRAL PLAINS. THAT SAID
THIS WILL BE THE NEXT WEATHER MAKER TO END THE WORK WEEK AND START
OF THE WEEKEND. THIS UPPER LEVEL TROUGH WILL CONTINUE TO DIG AS
IT MOVES EAST AND PIVOTS INTO THE MID ATLANTIC...ALL WHILE
BECOMING NEGATIVELY TILTED. THERE ARE SOME ISSUES THAT WILL HAVE
TO BE LOOKED AT WITH THIS SYSTEM MORE AS WE GET CLOSER. THE FIRST
IS AS THE TROUGH NEGATIVELY TILTS ALONG THE MID ATLANTIC AND A
300MB JET STREAK PUNCHES IN FROM THE GULF OF MEXICO...A SURFACE
LOW WILL CONTINUE TO DEEPEN ACROSS THE SE. THIS COULD PLAY A ROLE
IN CUTTING OFF SOME OF THE MOISTURE WITH THIS SYSTEM AND WILL
HAVE TO BE RESOLVED FURTHER...THE NAM AND GFS HAVE THE MOST
CONSISTENCY WITH BETTER QPF NW ACROSS NORTH CENTRAL KY. EVEN SO
KEPT CLOSE TO PREVIOUS FORECAST IN TERMS OF POPS GIVEN THE FACT
THAT WE WILL PROBABLY SEE SOMETHING MEASURABLE. NOW THE BEST LIFT
WILL BE IN THE EVENING HOURS ON FRIDAY AND LIFT TRAILS OFF FROM
THERE.
THE NEXT ISSUE WILL BE TRANSITION FROM RAIN TO SNOW
OVERNIGHT...RIGHT NOW TRANSITION IN THE FAR WEST NEAR DAWN AND
MOVE THAT TRANSITION THROUGH THE MORNING. IT DOES LOOK LIKE MUCH
OF THIS SHOULD REMAIN SNOW SHOWER ON SATURDAY. OVERALL NOT LOOKING
AT MUCH IN TERMS OF ACCUMULATION GIVEN THE WARM TEMPS PRIOR. AFTER
THIS WE ARE POISED TO MOVE BACK TO THE MUCH COLDER AIR AFTER THE
QUICK WARM UP. RIGHT NOW MODELS ARE HAVING TROUBLE RESOLVING WHAT
WILL HAPPEN HERE SUNDAY...BUT SEEMS LIKE THEY ARE CATCHING ON TO
THE FACT THAT ANOTHER ARCTIC FRONT WILL PASS ACROSS THE REGION.
THAT SAID DID LEAN TOWARD THE BLEND FOR THIS WHICH BRINGS SOME
SLIGHT TO CHANCE POPS INTO THE PICTURE...ANY SNOW ACCUM IS
EXPECTED TO REMAIN LIGHT. THAT SAID SOME MUCH COLD AIR ARRIVES
INTO THE REGION BEHIND THIS FRONT...WITH 850MB TEMPS IN THE MINUS
20 RANGE NOT OUT OF THE QUESTION. MONDAY COULD BE THE FIRST TIME
THIS WINTER SEASON THAT WE ONLY MAKE IT INTO THE MID TO UPPER 20S
FOR MOST. OVERNIGHT LOWS FOR BOTH SUNDAY AND MONDAY NIGHT WILL
LIKELY BE IN THE TEENS WITH SINGLE DIGITS CERTAINLY NOT OUT OF THE
REALM OF POSSIBILITY PARTICULARLY MONDAY NIGHT. ALL THIS SAID
WITH SURFACE HIGH BUILDING THE FIRST PART OF YOUR WORK WEEK LOOKS
WELL BELOW AVERAGE TEMP WISE...BUT WILL REMAIN DRY.
OVERALL STUCK WITH MODEL BLEND THROUGH THE PERIOD...DID GO HIGHER
THAN BLEND IN LINE WITH PREVIOUS FORECAST FOR THE WEEKEND SYSTEM.
ALSO TEMP WISE ON FRIDAY DID BUMP THAT UP JUST GIVEN THE STRONG
LLJ THAT KICKS INTO GEAR IN THE AFTERNOON. ALSO KEPT THE FORECAST
DRY FOR MONDAY WITH MOST OF THE MODELS NOW DEPICTING THAT THOUGHT.
DID ADD SOME RIDGE/VALLEY SPLITS AT THE END OF THE PERIOD
PARTICULARLY AS HIGH CRESTS ACROSS THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 725 AM EST WED JAN 13 2016
CONDITIONS WILL BE VFR THROUGH THE PERIOD AS AN AREA OF HIGH
PRESSURE MOVES IN. THIS WILL CONTINUE THE LIGHT WINDS...AT LESS
THAN 10 KNOTS...GENERALLY FROM THE WEST TO SOUTHWEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
750 AM EST WED JAN 13 2016
.UPDATE...
ISSUED AT 750 AM EST WED JAN 13 2016
DID A QUICK UPDATE MAINLY TO FINE TUNE THE TD AND T GRIDS PER THE
LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EST WED JAN 13 2016
07Z SFC ANALYSIS SHOWS COLD HIGH PRESSURE BUILDING INTO KENTUCKY.
THIS IS HELPING TO SETTLE THE WINDS AND HAS CLEARED THE SKY. AS A
RESULT...TEMPERATURES ARE DROPPING TOWARD 10 DEGREES IN THE
EASTERN VALLEYS AND NORTHWEST PARTS OF THE AREA WHILE MID AND
UPPER TEENS ARE FOUND ON THE RIDGES AND THROUGH THE CUMBERLAND
VALLEY. DEWPOINTS...MEANWHILE ARE IN THE SINGLE DIGITS MOST
PLACES. THE SNOW SQUALLS OF TUESDAY AFTERNOON SPARED MOST
LOCATIONS GENERALLY SOUTH OF THE MOUNTAIN PARKWAY BUT DID MANAGE
TO LAY DOWN A LAYER OF SNOW OF VARYING THICKNESS NORTH OF THE
HIGHWAY...AND PARTICULARLY FOR POINTS ALONG AND NORTH OF
INTERSTATE 64. THESE PLACES WILL RADIATE EXTRA WELL FOR THE REST
OF THE NIGHT WITH SOME SINGLE DIGITS CERTAINLY POSSIBLE BY DAWN.
WILL LIKELY DO SOME FINAL ADJUSTMENTS TEMPS IN THESE PLACES
BEFORE GRID ISSUANCE.
THE MODELS ARE IN EXCELLENT AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST. THEY ALL DEPICT A CLUSTER OF WEAK
MID LEVEL WAVES PASSING THROUGH THE OHIO VALLEY TODAY AND TONIGHT
IN NORTHWEST FLOW...EVEN AS THE HEIGHTS CONTINUE TO REBOUND.
EASTERN KENTUCKY WILL GET INTO SOME SLIGHT RIDGING ON THURSDAY
AHEAD OF A STILL UNCONSOLIDATED TROUGH MOVING INTO THE CENTRAL
PLAINS AND ANOTHER WEAK ONE LIFTING NORTHEAST FROM NORTHERN
MEXICO IN THE SOUTHERN STREAM. LOOK FOR THESE TO START TO INTERACT
AND BRING A CHANCE OF RAIN TO THE AREA EARLY IN THE EXTENDED. IN
THE MEANTIME...THOUGH...A QUIET MID LEVELS AND DRY AIR IN PLACE
WILL KEEP THE WEATHER RATHER BENIGN THROUGH THURSDAY. HAVE FAVORED
THE HIGHER RESOLUTION GUIDANCE FROM THE HRRR AND NAM12 FOR
FORECAST DETAILS.
SENSIBLE WEATHER WILL FEATURE A CHILLY START WITH TEMPERATURES IN
THE TEENS AND SINGLE DIGITS THIS MORNING ALONG WITH WIND CHILLS
NEAR ZERO AT TIMES. HOWEVER...PLENTY OF SUNSHINE IN THE MORNING
WILL HELP THE MERCURY REBOUND TO ABOVE FREEZING AND INTO THE MID
30S DURING THE AFTERNOON...FOR MOST PLACES WITHOUT A SNOW PACK.
LOCATIONS ALONG AND NORTH OF INTERSTATE 64 WILL STRUGGLE TO SEE
FREEZING TEMPS...THOUGH. A PASSING AREA OF LOW PRESSURE TO THE
NORTH WILL BRING SOME MID LEVEL CLOUDS TO THE NORTHERN PARTS OF
THE CWA THIS AFTERNOON AND EVENING BUT NO PCPN OR FLURRIES ARE
EXPECTED FROM THESE. MILDER TEMPERATURES ARE ON TAP FOR TONIGHT AS
WARMER AIR STARTS TO MOVE IN AND THE HIGH RETREATS TO THE EAST.
THE WARMUP WILL BE MOST PRONOUNCED ON THURSDAY WHEN SOUTHWEST
WINDS KICK IN SUPPORTING TEMPERATURES TOPPING OUT IN THE UPPER 40S
AND LOWER 50S.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR TEMPS AND
DEWPOINTS THROUGH THE EVENING FOLLOWED BY THE SUPERBLEND. DID MAKE
SOME ADJUSTMENTS TONIGHT TO HIGHLIGHT A DECENT RIDGE TO VALLEY
TEMPERATURE SPLIT. AS FOR POPS...THEY ARE BASICALLY LOW SINGLE
DIGITS OR NEAR ZERO THROUGH THE SHORT TERM...IN LINE WITH MOS
GUIDANCE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 335 AM EST WED JAN 13 2016
BIG STORY TO BEGIN THIS PERIOD WILL BE THE CONTINUED ABOVE AVERAGE
TEMPERATURES. WE BEGIN THE PERIOD WITH SURFACE HIGH PARKED TO OUR
SOUTHEAST AND IN THE WARM SECTOR. THIS WILL BE AHEAD OF DEEPENING
UPPER LEVEL TROUGH ACROSS THE NORTHERN CENTRAL PLAINS. THAT SAID
THIS WILL BE THE NEXT WEATHER MAKER TO END THE WORK WEEK AND START
OF THE WEEKEND. THIS UPPER LEVEL TROUGH WILL CONTINUE TO DIG AS
IT MOVES EAST AND PIVOTS INTO THE MID ATLANTIC...ALL WHILE
BECOMING NEGATIVELY TILTED. THERE ARE SOME ISSUES THAT WILL HAVE
TO BE LOOKED AT WITH THIS SYSTEM MORE AS WE GET CLOSER. THE FIRST
IS AS THE TROUGH NEGATIVELY TILTS ALONG THE MID ATLANTIC AND A
300MB JET STREAK PUNCHES IN FROM THE GULF OF MEXICO...A SURFACE
LOW WILL CONTINUE TO DEEPEN ACROSS THE SE. THIS COULD PLAY A ROLE
IN CUTTING OFF SOME OF THE MOISTURE WITH THIS SYSTEM AND WILL
HAVE TO BE RESOLVED FURTHER...THE NAM AND GFS HAVE THE MOST
CONSISTENCY WITH BETTER QPF NW ACROSS NORTH CENTRAL KY. EVEN SO
KEPT CLOSE TO PREVIOUS FORECAST IN TERMS OF POPS GIVEN THE FACT
THAT WE WILL PROBABLY SEE SOMETHING MEASURABLE. NOW THE BEST LIFT
WILL BE IN THE EVENING HOURS ON FRIDAY AND LIFT TRAILS OFF FROM
THERE.
THE NEXT ISSUE WILL BE TRANSITION FROM RAIN TO SNOW
OVERNIGHT...RIGHT NOW TRANSITION IN THE FAR WEST NEAR DAWN AND
MOVE THAT TRANSITION THROUGH THE MORNING. IT DOES LOOK LIKE MUCH
OF THIS SHOULD REMAIN SNOW SHOWER ON SATURDAY. OVERALL NOT LOOKING
AT MUCH IN TERMS OF ACCUMULATION GIVEN THE WARM TEMPS PRIOR. AFTER
THIS WE ARE POISED TO MOVE BACK TO THE MUCH COLDER AIR AFTER THE
QUICK WARM UP. RIGHT NOW MODELS ARE HAVING TROUBLE RESOLVING WHAT
WILL HAPPEN HERE SUNDAY...BUT SEEMS LIKE THEY ARE CATCHING ON TO
THE FACT THAT ANOTHER ARCTIC FRONT WILL PASS ACROSS THE REGION.
THAT SAID DID LEAN TOWARD THE BLEND FOR THIS WHICH BRINGS SOME
SLIGHT TO CHANCE POPS INTO THE PICTURE...ANY SNOW ACCUM IS
EXPECTED TO REMAIN LIGHT. THAT SAID SOME MUCH COLD AIR ARRIVES
INTO THE REGION BEHIND THIS FRONT...WITH 850MB TEMPS IN THE MINUS
20 RANGE NOT OUT OF THE QUESTION. MONDAY COULD BE THE FIRST TIME
THIS WINTER SEASON THAT WE ONLY MAKE IT INTO THE MID TO UPPER 20S
FOR MOST. OVERNIGHT LOWS FOR BOTH SUNDAY AND MONDAY NIGHT WILL
LIKELY BE IN THE TEENS WITH SINGLE DIGITS CERTAINLY NOT OUT OF THE
REALM OF POSSIBILITY PARTICULARLY MONDAY NIGHT. ALL THIS SAID
WITH SURFACE HIGH BUILDING THE FIRST PART OF YOUR WORK WEEK LOOKS
WELL BELOW AVERAGE TEMP WISE...BUT WILL REMAIN DRY.
OVERALL STUCK WITH MODEL BLEND THROUGH THE PERIOD...DID GO HIGHER
THAN BLEND INLINE WITH PREVIOUS FORECAST FOR THE WEEKEND SYSTEM.
ALSO TEMP WISE ON FRIDAY DID BUMP THAT UP JUST GIVEN THE STRONG
LLJ THAT KICKS INTO GEAR IN THE AFTERNOON. ALSO KEPT THE FORECAST
DRY FOR MONDAY WITH MOST OF THE MODELS NOW DEPICTING THAT THOUGHT.
DID ADD SOME RIDGE/VALLEY SPLITS AT THE END OF THE PERIOD
PARTICULARLY AS HIGH CRESTS ACROSS THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 725 AM EST WED JAN 13 2016
CONDITIONS WILL BE VFR THROUGH THE PERIOD AS AN AREA OF HIGH
PRESSURE MOVES IN. THIS WILL CONTINUE THE LIGHT WINDS...AT LESS
THAN 10 KNOTS...GENERALLY FROM THE WEST TO SOUTHWEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
335 AM EST WED JAN 13 2016
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 335 AM EST WED JAN 13 2016
07Z SFC ANALYSIS SHOWS COLD HIGH PRESSURE BUILDING INTO KENTUCKY.
THIS IS HELPING TO SETTLE THE WINDS AND HAS CLEARED THE SKY. AS A
RESULT...TEMPERATURES ARE DROPPING TOWARD 10 DEGREES IN THE
EASTERN VALLEYS AND NORTHWEST PARTS OF THE AREA WHILE MID AND
UPPER TEENS ARE FOUND ON THE RIDGES AND THROUGH THE CUMBERLAND
VALLEY. DEWPOINTS...MEANWHILE ARE IN THE SINGLE DIGITS MOST
PLACES. THE SNOW SQUALLS OF TUESDAY AFTERNOON SPARED MOST
LOCATIONS GENERALLY SOUTH OF THE MOUNTAIN PARKWAY BUT DID MANAGE
TO LAY DOWN A LAYER OF SNOW OF VARYING THICKNESS NORTH OF THE
HIGHWAY...AND PARTICULARLY FOR POINTS ALONG AND NORTH OF
INTERSTATE 64. THESE PLACES WILL RADIATE EXTRA WELL FOR THE REST
OF THE NIGHT WITH SOME SINGLE DIGITS CERTAINLY POSSIBLE BY DAWN.
WILL LIKELY DO SOME FINAL ADJUSTMENTS TEMPS IN THESE PLACES
BEFORE GRID ISSUANCE.
THE MODELS ARE IN EXCELLENT AGREEMENT ALOFT THROUGH THE SHORT
TERM PORTION OF THE FORECAST. THEY ALL DEPICT A CLUSTER OF WEAK
MID LEVEL WAVES PASSING THROUGH THE OHIO VALLEY TODAY AND TONIGHT
IN NORTHWEST FLOW...EVEN AS THE HEIGHTS CONTINUE TO REBOUND.
EASTERN KENTUCKY WILL GET INTO SOME SLIGHT RIDGING ON THURSDAY
AHEAD OF A STILL UNCONSOLIDATED TROUGH MOVING INTO THE CENTRAL
PLAINS AND ANOTHER WEAK ONE LIFTING NORTHEAST FROM NORTHERN
MEXICO IN THE SOUTHERN STREAM. LOOK FOR THESE TO START TO INTERACT
AND BRING A CHANCE OF RAIN TO THE AREA EARLY IN THE EXTENDED. IN
THE MEANTIME...THOUGH...A QUIET MID LEVELS AND DRY AIR IN PLACE
WILL KEEP THE WEATHER RATHER BENIGN THROUGH THURSDAY. HAVE FAVORED
THE HIGHER RESOLUTION GUIDANCE FROM THE HRRR AND NAM12 FOR
FORECAST DETAILS.
SENSIBLE WEATHER WILL FEATURE A CHILLY START WITH TEMPERATURES IN
THE TEENS AND SINGLE DIGITS THIS MORNING ALONG WITH WIND CHILLS
NEAR ZERO AT TIMES. HOWEVER...PLENTY OF SUNSHINE IN THE MORNING
WILL HELP THE MERCURY REBOUND TO ABOVE FREEZING AND INTO THE MID
30S DURING THE AFTERNOON...FOR MOST PLACES WITHOUT A SNOW PACK.
LOCATIONS ALONG AND NORTH OF INTERSTATE 64 WILL STRUGGLE TO SEE
FREEZING TEMPS...THOUGH. A PASSING AREA OF LOW PRESSURE TO THE
NORTH WILL BRING SOME MID LEVEL CLOUDS TO THE NORTHERN PARTS OF
THE CWA THIS AFTERNOON AND EVENING BUT NO PCPN OR FLURRIES ARE
EXPECTED FROM THESE. MILDER TEMPERATURES ARE ON TAP FOR TONIGHT AS
WARMER AIR STARTS TO MOVE IN AND THE HIGH RETREATS TO THE EAST.
THE WARMUP WILL BE MOST PRONOUNCED ON THURSDAY WHEN SOUTHWEST
WINDS KICK IN SUPPORTING TEMPERATURES TOPPING OUT IN THE UPPER 40S
AND LOWER 50S.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR TEMPS AND
DEWPOINTS THROUGH THE EVENING FOLLOWED BY THE SUPERBLEND. DID MAKE
SOME ADJUSTMENTS TONIGHT TO HIGHLIGHT A DECENT RIDGE TO VALLEY
TEMPERATURE SPLIT. AS FOR POPS...THEY ARE BASICALLY LOW SINGLE
DIGITS OR NEAR ZERO THROUGH THE SHORT TERM...IN LINE WITH MOS
GUIDANCE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 335 AM EST WED JAN 13 2016
BIG STORY TO BEGIN THIS PERIOD WILL BE THE CONTINUED ABOVE AVERAGE
TEMPERATURES. WE BEGIN THE PERIOD WITH SURFACE HIGH PARKED TO OUR
SOUTHEAST AND IN THE WARM SECTOR. THIS WILL BE AHEAD OF DEEPENING
UPPER LEVEL TROUGH ACROSS THE NORTHERN CENTRAL PLAINS. THAT SAID
THIS WILL BE THE NEXT WEATHER MAKER TO END THE WORK WEEK AND START
OF THE WEEKEND. THIS UPPER LEVEL TROUGH WILL CONTINUE TO DIG AS
IT MOVES EAST AND PIVOTS INTO THE MID ATLANTIC...ALL WHILE
BECOMING NEGATIVELY TILTED. THERE ARE SOME ISSUES THAT WILL HAVE
TO BE LOOKED AT WITH THIS SYSTEM MORE AS WE GET CLOSER. THE FIRST
IS AS THE TROUGH NEGATIVELY TILTS ALONG THE MID ATLANTIC AND A
300MB JET STREAK PUNCHES IN FROM THE GULF OF MEXICO...A SURFACE
LOW WILL CONTINUE TO DEEPEN ACROSS THE SE. THIS COULD PLAY A ROLE
IN CUTTING OFF SOME OF THE MOISTURE WITH THIS SYSTEM AND WILL
HAVE TO BE RESOLVED FURTHER...THE NAM AND GFS HAVE THE MOST
CONSISTENCY WITH BETTER QPF NW ACROSS NORTH CENTRAL KY. EVEN SO
KEPT CLOSE TO PREVIOUS FORECAST IN TERMS OF POPS GIVEN THE FACT
THAT WE WILL PROBABLY SEE SOMETHING MEASURABLE. NOW THE BEST LIFT
WILL BE IN THE EVENING HOURS ON FRIDAY AND LIFT TRAILS OFF FROM
THERE.
THE NEXT ISSUE WILL BE TRANSITION FROM RAIN TO SNOW
OVERNIGHT...RIGHT NOW TRANSITION IN THE FAR WEST NEAR DAWN AND
MOVE THAT TRANSITION THROUGH THE MORNING. IT DOES LOOK LIKE MUCH
OF THIS SHOULD REMAIN SNOW SHOWER ON SATURDAY. OVERALL NOT LOOKING
AT MUCH IN TERMS OF ACCUMULATION GIVEN THE WARM TEMPS PRIOR. AFTER
THIS WE ARE POISED TO MOVE BACK TO THE MUCH COLDER AIR AFTER THE
QUICK WARM UP. RIGHT NOW MODELS ARE HAVING TROUBLE RESOLVING WHAT
WILL HAPPEN HERE SUNDAY...BUT SEEMS LIKE THEY ARE CATCHING ON TO
THE FACT THAT ANOTHER ARCTIC FRONT WILL PASS ACROSS THE REGION.
THAT SAID DID LEAN TOWARD THE BLEND FOR THIS WHICH BRINGS SOME
SLIGHT TO CHANCE POPS INTO THE PICTURE...ANY SNOW ACCUM IS
EXPECTED TO REMAIN LIGHT. THAT SAID SOME MUCH COLD AIR ARRIVES
INTO THE REGION BEHIND THIS FRONT...WITH 850MB TEMPS IN THE MINUS
20 RANGE NOT OUT OF THE QUESTION. MONDAY COULD BE THE FIRST TIME
THIS WINTER SEASON THAT WE ONLY MAKE IT INTO THE MID TO UPPER 20S
FOR MOST. OVERNIGHT LOWS FOR BOTH SUNDAY AND MONDAY NIGHT WILL
LIKELY BE IN THE TEENS WITH SINGLE DIGITS CERTAINLY NOT OUT OF THE
REALM OF POSSIBILITY PARTICULARLY MONDAY NIGHT. ALL THIS SAID
WITH SURFACE HIGH BUILDING THE FIRST PART OF YOUR WORK WEEK LOOKS
WELL BELOW AVERAGE TEMP WISE...BUT WILL REMAIN DRY.
OVERALL STUCK WITH MODEL BLEND THROUGH THE PERIOD...DID GO HIGHER
THAN BLEND INLINE WITH PREVIOUS FORECAST FOR THE WEEKEND SYSTEM.
ALSO TEMP WISE ON FRIDAY DID BUMP THAT UP JUST GIVEN THE STRONG
LLJ THAT KICKS INTO GEAR IN THE AFTERNOON. ALSO KEPT THE FORECAST
DRY FOR MONDAY WITH MOST OF THE MODELS NOW DEPICTING THAT THOUGHT.
DID ADD SOME RIDGE/VALLEY SPLITS AT THE END OF THE PERIOD
PARTICULARLY AS HIGH CRESTS ACROSS THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 120 AM EST WED JAN 13 2016
CONDITIONS WILL BE VFR FOR THE REMAINDER OF THE NIGHT AND INTO
THE DAY WEDNESDAY AS AN AREA OF HIGH PRESSURE MOVES IN OVERHEAD.
THIS WILL CONTINUE TO SETTLE THE WINDS...DROPPING THEM TO LESS
THAN 10 KNOTS FOR THE REMAINDER OF THE PERIOD...GENERALLY FROM THE
WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS GRAY ME
1110 PM EST TUE JAN 12 2016
.SYNOPSIS...
LOW PRESSURE MOVING ACROSS THE GULF OF MAINE TONIGHT WILL
INTENSIFY AS IT MOVES NORTHEAST INTO THE MARITIMES ON WEDNESDAY.
THIS WILL PRODUCE A ROUND OF SNOW TONIGHT...HEAVY AT TIMES ACROSS
CENTRAL AND MIDCOAST MAINE. AS THE STORM EXITS IT WILL ALSO
PRODUCE WINDY BUT FAIR CONDITIONS ON WEDNESDAY. HIGH PRESSURE
BUILDS IN THURSDAY AND FRIDAY. ANOTHER ROUND OF SNOW...POSSIBLY
RAIN NEAR THE COAST IS EXPECTED ON SATURDAY...WITH COLDER AIR
MOVING IN SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
1110 PM UPDATE...HAVE ISSUED A SPECIAL WEATHER STATEMENT FOR THE
HEAVY SNOW BAND THAT IS MOVING ACROSS SOUTHERN AND CENTRAL MAINE.
HOURLY RATES OF UP TO 3 INCHES ARE LIKELY...ALONG WITH ISOLATED
THUNDER. HAVE EXPANDED THE WINTER STORM WARNING TO ANDROSCOGGIN
COUNTY FOR THE NEXT FEW HOURS AS MORE THAN 6 INCHES IS NOW
EXPECTED BASED ON UPSTREAM REPORTS OVER INTERIOR CUMBERLAND
COUNTY.
1020 PM UPDATE...HAVE UPDATED THE FORECAST BASED ON LATEST TRENDS
IN RADAR AND OTHER OBSERVATIONAL DATA. THE BACK EDGE OF THE HEAVY
SNOW SHIELD IS MOVING QUICKLY TO THE NORTHEAST ACROSS SOUTHERNMOST
ME AND THIS TREND WILL CONTINUE. RAIN HUGGING THE MAINE COAST WILL
GRADUALLY GO BACK OVER TO SNOW OVER THE NEXT FEW HOURS FROM SOUTH
TO NORTH. HAVE CANCELLED THE ADVISORIES FOR SOUTHERN NH AS THE
SNOW HAS ENDED THERE. A FEW SQUALLS MAY AFFECT WESTERN ZONES
OVERNIGHT HOWEVER.
PREVIOUSLY...
A POTENT S/WV TROF IS CROSSING THE ERN GREAT LAKES AT THIS
HOUR...AND WILL BRING SOME SIGNIFICANT IMPACTS TO THE AREA THIS
EVENING AND TONIGHT.
THE STRENGTH OF THIS S/WV IS EVIDENT IN THE WILD WX THIS
AFTERNOON ACROSS UPSTATE NY. THUNDER HAS BEEN REPORTED AROUND BUF
IN HEAVY SNWFL...WITH WIND GUSTS IN EXCESS OF 60 MPH. THESE
SQUALLS MARK THE LEADING EDGE OF THE S/WV TROF. AHEAD OF
IT...INCREASING SLY FLOW AND WAA IS ALLOWING LIGHT SNWFL TO BREAK
OUT. THIS WILL INCREASE IN COVERAGE AND INTENSITY AS THE S/WV
APPROACHES. THIS WILL LEAD TO MINOR ACCUMULATIONS THRU THE EVENING
COMMUTE...BUT COULD LEAD TO SLIPPERY ROADS WITH TEMPS NEAR
FREEZING.
ATTENTION THEN TURNS TO THAT LEADING EDGE OF THE S/WV AND
ATTENDANT SQUALLS. HI-RES MODEL GUIDANCE SUGGESTS IT BECOMES
DIFFICULT TO DISTINGUISH BETWEEN THE LINE OF SN SHOWERS AND THE
DEVELOPING STRONG INFLOW JET FORECAST TO FORM NEAR SERN NH. 12Z
MODEL GUIDANCE SHIFTED THIS AREA OF FORMATION SLIGHTLY SW FROM 00Z
MODEL SUITE. THIS BRINGS AREAS LIKE MHT AND ASH A LITTLE CLOSER TO
THE BRIEF HEAVY SNWFL THREAT. HRRR GUIDANCE...ALONG WITH
ARW...NMM...AND REGIONAL CMC ALL SHOW THE POTENTIAL FOR QPF...AND
THUS SNWFL...TO BRIEFLY BE HEAVY AS THIS INFLOW JET SWEEPS NEWD
THRU THE FORECAST AREA. SNWFL RATES MAY EXCEED 1 TO 3 INCHES PER
HOUR IN THE HEAVIEST SNWFL...THOUGH MAY ONLY LAST FOR AN HOUR OR
SO. MIXING ANY OF THAT WIND ALOFT DOWN IN HEAVY SHOWERS COULD ALSO
BRING 30 TO 35 MPH GUSTS...WHICH WOULD LEAD TO NEAR ZERO
VISIBILITY AT TIMES. I HAVE AN SPS IN EFFECT TO HIGHLIGHT THIS
SHORT DURATION...HEAVY SNWFL ASPECT OF THE SYSTEM. IN
ADDITION...LAPSE RATES ALOFT EXCEED 7 C/KM...SUFFICIENT FOR STRONG
WARM SEASON CONVECTION LET ALONE WINTER. WILL KEEP THUNDER IN THE
FORECAST FOR AREAS NEAR THE COAST WHERE THIS UNSTABLE AIR MASS IS
ABLE TO MOVE IN OFF THE WATER. ANY CONVECTION WILL FURTHER ENHANCE
THOSE SNWFL RATES.
S/WV TROF CONTINUES NEGATIVE TILT THRU THE AREA...AND BAND OF
SNWFL SHOULD BEGIN TO SLOW AND PIVOT AS IT APPROACHES CENTRAL ME.
HEAVIEST AMOUNTS WILL BE IN OUR ERN ZONES...GENERALLY FROM AUG
NEWD. AGAIN WILL HAVE TO MONITOR BOUNDARY LAYER TEMPS NEAR THE
COAST...AS MODELS CONTINUE TO SUGGEST WARMING MAKING IT WELL
INLAND. TEMPS ALOFT WOULD ARGUE THAT THIS STRUGGLES TO MAKE
PROGRESS MUCH PAST THE NECKS AND ISLANDS. CAPE ELIZABETH AND MAYBE
EVEN PWM MAY BE RA...WHILE THE TURNPIKE IS HEAVY SNWFL. HOWEVER
TOO MUCH UNCERTAINTY EXISTS TO CHANGE HEADLINES FROM WHERE WE HAVE
THEM CURRENTLY. SNWFL AMOUNTS LOOK VERY SIMILAR TO PREVIOUS
SHIFT...MAYBE SLIGHTLY HIGHER OVER SWRN ME. HOWEVER THESE STILL
FALL WITHIN ADVISORY RANGE. STILL A LOW CHANCE THAT SOME OF THE
ADVISORY MAY NEED TO BE CONVERTED TO WARNINGS AS THE BANDING SETS
UP.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
LOW PRES DEEPENS INTO THE 970S OVER THE CANADIAN MARITIMES
WED...SETTING UP A STRONG PRES GRADIENT ACROSS THE AREA. FLOW IN
CAA WILL BECOME GUSTY EARLY WED...INCREASING IN THE AFTERNOON AS
THE CORE OF WLY JET AROUND 5000 FEET MOVES OVERHEAD. BUFKIT
SOUNDINGS SHOW SOME POTENTIAL TO MIX DOWN SOME OF THIS JET...WITH
A FEW MODELS SHOWING GUSTS IN THE 40 TO 45 KT RANGE. GIVEN THAT A
WIND HEADLINE WOULD COMPLICATE AN ALREADY COMPLICATED FORECAST
EVEN FURTHER...WILL HOLD OFF FOR NOW AND ALLOW THE MIDNIGHT SHIFT
TO REASSESS.
UPSLOPE SN SHOWERS WILL LINGER OVER THE NRN ZONES IN WLY FLOW WED.
AN ADDITIONAL COUPLE OF INCHES IS POSSIBLE IN THE FAVORED AREAS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGH IMPACT WX: LOW CONFIDENCE FOR SIGNIFICANT SNOW CENTERED
AROUND SATURDAY.
THE 500 MB PATTERN CONTINUES TO BUILD WEAK TO MODERATE RIDGING
ACROSS THE WRN CONUS AND ERN PACIFIC...WITH A MEAN...BUT
FLUCTUATING TROUGH OVER THE ERN CONUS. ALL IN ALL THOUGH...SO
CALLED PINEAPPLE EXPRESS ACROSS THE PACIFIC WILL PROVIDE ENOUGH
WAVES TO CONTINUALLY KNOCK DOWN THE RIDGE IN THE WEST...AND LACK
OF COLD AIR OVER NOAM WILL LIMIT THERMAL ADVECTION ENOUGH IN THE
ARCTIC TO MINIMIZE WAVE PRODUCTION TO MAINTAIN SOLID TROUGH OVER
ERN CONUS. THIS...WILL SEE SOME CHANGEABLE CONDS THRU THE EXTENDED
WITH TEMPS FLUCTUATING SEVERAL DEGREES EITHER SIDE OF NORMAL.
SENSIBLE WX WILL SEE SFC RIDGE SLOWLY PASSING TO OUR S THU AND
FRI...WITH SFC LOW MOVING NE INTO THE GREAT LAKES FRI NIGHT. 500MB
WEAVE ROTATING AROUND THE BASE OF THE TROUGH WILL DEVELOP COASTAL
BY SAT MORNING WHICH TRACKS OFF NEW ENGLAND COAST SAT. THIS WILL
BE OUT NEXT PRECIP MAKER. MED RANGE MODELS IN BETTER AGREEMENT ON
TIMING...WITH PRECIP STARTING SOMETIME FRI NIGHT AND ENDING SAT
NIGHT. TRACK AND INTENSITY FORECASTS VARY QUITE A
BIT...PARTICULARLY WHERE P-TYPE AND INTENSITY ARE CONCERNED WITH
THE GFS MOVING THE LOW FURTHEREST OFFSHORE...WHILE THE GGEM IS THE
CLOSEST...WITH THE EURO IN THE MIDDLE. SO WHILE SOME PRECIP CAN BE
EXPECTED...AND IT WILL LIKELY BE SNOW INLAND...EVERYTHING ELSE
STILL REMAINS LOW CONFIDENCE. UPPER LVL LOW CROSSES THE REGION
SUNDAY WITH SHSN POSSIBLE...AND COLDER HIGH PRESSURE EXPECTED
EARLY NEXT WEEK.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM...CONDITIONS WILL IMPROVE RAPIDLY FROM SW TO NE LATE
THIS EVENING AND OVERNIGHT AS THE SNOW SHIELD MOVES NORTHEASTWARD.
GUSTY WEST WINDS AND VFR CONDITIONS WILL FOLLOW LATER TONIGHT AND
WEDNESDAY.
LONG TERM...VFR WED NIGHT THROUGH FRI. FLIGHT RESTRICTIONS
EXPECTED LATE FRI NIGHT INTO SAT EVE IN SN...OR POSSIBLE RA NEAR
THE COAST. SOME IMPROVEMENT IS POSSIBLE ON SUN.
&&
.MARINE...
SHORT TERM...GALE WARNINGS REMAIN IN EFFECT FOR ALL WATERS THRU
WED. WINDS MAY GUST TO NEAR STORM FORCE FOR A TIME IN STRONG CAA
WED.
LONG TERM...WINDS GRADUALLY DIMINISH FROM GALES WED EVE...TO SCA
FOR THU....AND BELOW SCA THU NIGHT THRU FRI NIGHT. SCA OR GALES
POSSIBLE AGAIN SAT AND SAT NIGHT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 10 AM EST WEDNESDAY FOR MEZ008-009-
013-014-021-022-028.
WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR MEZ007-
012-019.
WINTER WEATHER ADVISORY UNTIL 10 AM EST WEDNESDAY FOR
MEZ025>027.
WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR MEZ024.
WINTER STORM WARNING UNTIL 3 AM EST WEDNESDAY FOR MEZ020.
NH...WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR NHZ001-
002.
MARINE...GALE WARNING UNTIL 11 PM EST WEDNESDAY FOR ANZ150>154.
&&
$$
NEAR TERM...EKSTER
SHORT TERM...LEGRO
LONG TERM...CEMPA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
710 PM EST THU JAN 14 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 258 PM EST THU JAN 14 2016
ONE LOW PRESSURE SYSTEM IN IOWA WILL TRACK EAST TONIGHT AND
THROUGH MICHIGAN ON FRIDAY. THIS SYSTEM COULD PRODUCE SOME LIGHT
RAIN. A COLDER AIRMASS RETURNS TO THE REGION FRIDAY NIGHT INTO
SATURDAY WITH LAKE EFFECT SNOW SHOWERS POSSIBLE NEAR THE
LAKESHORE. A REINFORCING SHOT OF ARCTIC AIR ARRIVES SUNDAY WITH
ACCUMULATING LAKE EFFECT SNOW LIKELY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 258 PM EST THU JAN 14 2016
GIVEN THE CLEARING SKIES AND WARM AIR ADVECTION I DOWNPLAYED THE
POTENTIAL FOR SLEET AND FREEZING RAIN TONIGHT. STILL THE NORTHEAST
COUNTIES WILL BE CLOSE TO THE WARM FRONT AND A SMALL RISK EXISTS
UP THERE. TOO LOW FOR ANY HEADLINE AT THIS POINT. THE HRRR RUC WAS
SHOWING FOG TRYING TO DEVELOP LATER TONIGHT. I ADDED THIS TO THE
FORECAST.
A BETTER RISK FOR MEASURABLE RAIN EXISTS FOR FRIDAY. THE WAVE OF
LOW PRESSURE TRACKS EASTWARD THROUGH THE CWA. ENOUGH FORCING AND
MOISTURE AROUND FOR LIGHT RAIN. AT THIS POINT IT APPEARS THAT MOST
LOCATIONS WILL SEE LESS THAN A QUARTER INCH.
COLDER AIR RETURNS QUICKLY BEHIND THE DEPARTING LOW. THUS FRIDAY
NIGHT LOOKS LIKE MAINLY SNOW...IF ANY PRECIPITATION AT ALL. I AM
NOT CONFIDENT THAT WE WILL SEE MUCH PRECIPITATION AS THIS INITIAL
COLDER AIRMASS BEHIND THE LOW IS NOT THAT COLD...850 MB TEMPS DOWN
TO -8 DEG C OR SO. A BETTER SURGE OF ARCTIC AIR MOVES IN FOR LATER
SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 258 PM EST THU JAN 14 2016
WE STILL EXPECT A FEW INCHES OF LAKE EFFECT SNOW ON SUNDAY AND INTO
MONDAY. THE BULK OF THIS WILL FALL ON SUNDAY WITH A GENERAL 3 TO 5
INCHES ACROSS THE WESTERN ZONES. SNOW SHOWERS SHOULD REACH FAR
INLAND AS THE FLOW WILL BE FROM ABOUT 280 DEGREES WITH SOME ENHANCED
LOW LEVEL CONVERGENCE POSSIBLE ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA.
SUNDAY ALSO LOOKS MIGHTY COLD WITH 850 MB TEMPS BLO MINUS 20C AND
STRONG CAA ALL DAY. CORE OF THE COLDEST AIR COMES THROUGH DURING THE
AFTERNOON AND EVENING SO MAX TEMPS MIGHT OCCUR SUNDAY MORNING WITH
STEADY FOR FALLING TEMPERATURES DURING THE DAY AND WIND CHILLS
POSSIBLY GETTING DOWN TO 10 BELOW DURING THE EVENING.
MONDAY WILL SEE LAKE EFFECT SNOW SHOWERS CONTINUE WITH CYCLONIC FLOW
BUT ACCUMS ARE LIMITED BY INVERSION HEIGHTS AOB 5 KFT AND THE DGZ
NEAR THE SFC...SO ONLY ANOTHER INCH OR TWO EXPECTED.
THERE WILL BE A SLOW MODERATION IN TEMPERATURES FROM TUESDAY THROUGH
THURSDAY. IT REMAINS COLD ENOUGH FOR OCCASIONAL LAKE EFFECT SNOW
SHOWERS...ALTHOUGH AMOUNTS ARE EXPECTED TO BE LIGHT AS INVERSION
HEIGHTS REMAIN AOB 5 KFT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 710 PM EST THU JAN 14 2016
VFR CONDITIONS WILL PREVAIL THIS EVENING... AND CONFIDENCE IS
CURRENTLY LOW REGARDING THE AMOUNT OF FOG/STRATUS THAT MAY
DEVELOP OVERNIGHT... SO VFR MAY EVEN CONTINUE THROUGH 12Z FRIDAY.
THE ARRIVAL OF SFC DEW POINTS IN THE MID TO UPPER 30S TONIGHT
ACROSS THE SNOWPACK SUGGESTS A GOOD CHANCE OF FOG/STRATUS... BUT
SFC WIND SPEEDS OF 10-15 KTS... AND MUCH HIGHER SPEEDS JUST OFF
THE SFC... IMPLY THAT ENOUGH MIXING WILL BE PRESENT TO
PREVENT/LIMIT FOG/STRATUS FORMATION. WINDS AT 2000 FT WILL BE
35-40 KTS MUCH OF THE NIGHT SO HAVE INCLUDED LLWS IN MOST OF THE
TAFS.
A MUCH BETTER CHANCE OF IFR TO PERHAPS EVEN LIFR CIGS EXISTS ON
FRIDAY... ESPECIALLY IN THE AFTERNOON... AS THE SFC LOW AND BAGGY
SFC PRESSURE GRADIENT MOVES OVERHEAD LEADING TO LIGHTER WINDS.
RAIN/DRIZZLE PROBABILITIES WILL ALSO INCREASE ON FRIDAY WHICH
SHOULD LOWER THE VSBYS BELOW 3 MILES AS WELL.
&&
.MARINE...
ISSUED AT 258 PM EST THU JAN 14 2016
SOUTH TO SOUTHEAST WINDS WILL INCREASE TONIGHT. THIS WILL CAUSE
WAVES TO BUILD CLOSE TO SMALL CRAFT ADVISORY CRITERIA. THE WINDS
WILL VEER TO THE NORTHWEST BY FRIDAY NIGHT. AS COLDER AIR WORKS IT
WAY IN THE WAVES WILL BUILD TO OVER 4 FEET. HAZARDOUS CONDITIONS
FOR SMALL CRAFT WILL PERSIST THROUGH THE WEEKEND.
&&
.HYDROLOGY...
ISSUED AT 108 PM EST THU JAN 14 2016
ICE JAMMING IS LIKELY AFFECTING THE GRAND RIVER AT ROBINSON
TOWNSHIP. WARMER TEMPERATURES ALONG WITH SOME RAINFALL FRIDAY MAY
HELP LOOSEN THE JAM AND SOFTEN THE ICE FURTHER. THE FLOATING ICE
ON THE RIVER DOES NOT LOOK PARTICULARLY THICK SO IT MAY NOT TAKE
MUCH TO FREE THE JAM UP WITH MORE FAVORABLE WEATHER CONDITIONS
THROUGH FRIDAY. ELSEWHERE THERE IS LIKELY SOME ICE BUILDING
UPSTREAM OF DIMONDALE ON THE GRAND RIVER. HOWEVER...THE RIVER
STAGE AT DIMONDALE IS WELL BELOW BANKFULL PRESENTLY. WE WILL
CONTINUE TO MONITOR AREA RIVERS. A DEEP FREEZE LATER THIS WEEKEND
INTO NEXT WEEK WILL PUT A STOP TO ICE MOVEMENT AND WILL ALLOW FOR
ICE TO REDEVELOP. IF THE ROBINSON TWP JAM DOES NOT RELEASE BY THE
TIME THE ARCTIC AIR ARRIVES THEN MORE SIGNIFICANT ISSUES MAY
DEVELOP POTENTIALLY...WITH FURTHER ICE FORMATION OCCURRING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...OSTUNO
AVIATION...MEADE
HYDROLOGY...HOVING
MARINE...MJS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
643 PM EST THU JAN 14 2016
.AVIATION...
RATHER PLEASANT WEATHER CONDITIONS DEVELOPED OVER SOUTHEASTERN
MICHIGAN THIS AFTERNOON WITH STEADY MIDLEVEL HEIGHTS RISING INTO THE
CENTRAL GREAT LAKES. RATHER DRY CONDITIONS HAVE BEEN ABLE TO WORK ON
NORTHWARD FROM JUDGING OBSERVATION TRENDS. THIS JUST DEPICTS HOW OUT
ON AN ISLAND THIS SATURATED NAM SOLUTION HAS BECOME. RAP IS NOT
NEARLY AS SATURATED IN THE LOW LEVELS TONIGHT...WORKED WITH THAT AND
MUCH OF THE INHERITED TAF FORECAST. DID KEEP THE MVFR DEVELOPMENT
OVERNIGHT...BUT HAVE SOME SERIOUS RESERVATIONS NOW ON THAT. A
SECONDARY LOW LEVEL THETA E GRADIENT OR PLUME IS SHOWN TO COAST ON
IN VERY LATE TONIGHT LIKELY AFTER 09Z. THERE MAY BE SOME POTENTIAL
FOR DRIZZLE FORMATION AS THE MOISTURE SURGE INTERACTS WITH THE WARM
FRONTAL BOUNDARY ACROSS THE NORTHERN CWA. ATTM...CONFIDENCE IS VERY
LOW IN THIS OCCURRING...BUT WILL BE THE FEATURE THAT BRING MVFR
STRATUS BACK IN. STREAMING LEAD WAVE ENERGY COULD BRING SOME
POTENTIAL FOR LIGHT SHOWERS EARLIER DURING THE DAY ON FRIDAY.
ATTM...WILL HOLD OFF UNTIL THE LATE AFTERNOON WHEN BEST OF SYNOPTIC
FORCING/STRONG CVA COLLAPSES UPON THE CWA. THE GENERAL FEELING IS TO
LET TRENDS PRESENT THEMSELF BEFORE GOING ALL IN.
FOR DTW...PLEASANT CONDITIONS DEVELOPED OVER THE TERMINAL THIS
EVENING WITH SOME UPPER LEVEL RIDGING SETTING IN. ALL THINGS
CONSIDERED...IT APPEARS A RATHER DRY AMBIENT ENVIRONMENT HAS SET UP.
THEREFORE...THERE IS LOW CONFIDENCE IN TIMING AND OCCURRENCE OF MVFR
TONIGHT AND WILL NOT CARRY ANY WARM DRIZZLE (ABOVE FREEZING SURFACE
TEMPERATURES). WILL FOLLOW THE THEME AND HOLD OFF ANY LIGHT RAIN
CHANCES UNTIL FRIDAY AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR CIGS AOB 5KFT TONIGHT. HIGH PROBABILITY AFTER 15Z FRIDAY.
* LOW FOR DRIZZLE OCCURENCE AFETR 06Z...HIGH PROBABILITY FOR SURFACE
TEMPERATURES ABOVE FREEZING.
&&
.PREV DISCUSSION...ISSUED 326 PM EST THU JAN 14 2016
DISCUSSION...
19Z WATER VAPOR IMAGERY REVEALS THINNING UPPER-LEVEL MOISTURE ACROSS
THE UPPER MIDWEST WITH A DIGGING TROUGH EMERGING FROM THE ROCKIES
ONTO THE HIGH PLAINS. AT THE SURFACE...LOW PRESSURE IS DEVELOPING IN
THE VICINITY OF SIOUX FALLS SD WITH A WARM FRONT EXTENDING EASTWARD
ROUGHLY ALONG THE M-59 CORRIDOR. LOW CLOUDS REMAIN PREVALENT NORTH
OF THIS FRONT THAT IS ONLY SLOWLY WORKING NORTHWARD. ISENTROPIC LIFT
IS RESULTING IN MAINLY VIRGA ALONG THE ELEVATED PORTION OF THE FRONT
WITH SOME ECHOES WORKING INTO THE TRI-CITIES AND NORTHERN THUMB. A
FEW LIGHT SNOW SHOWERS REMAIN POSSIBLE INTO THIS EVENING IN THESE
LOCALES AS THE COLUMN SLOWLY TRIES TO ACHIEVE SATURATION.
MAIN CHALLENGE TONIGHT IS ASSESSING LOW CLOUD/DRIZZLE POTENTIAL. NAM
IS ITS TYPICAL BULLISH SELF IN SATURATING THE LOW LEVELS AS MOISTER
AIR IS DRAWN NORTHWARD. IT IS PROJECTING LOW CLOUDS AT 18Z WHERE
DEWPOINT DEPRESSIONS WERE AROUND 10F OVER SOUTHERN IL/IN AND IT IS
ABOUT 10F TOO COLD IN THE RAW OUTPUT. AS A RESULT HAVE REMOVED
DRIZZLE MENTION SOUTH OF I-69. STILL FEEL THERE IS DRIZZLE AND
PERHAPS FOG POTENTIAL ALONG AND NORTH OF THE WARM FRONT /I-69/ WHERE
TEMPERATURES HAVE STRUGGLED AND VISIBILITIES HAVE BEEN DIMINISHED ALL
DAY. SOME FREEZING DRIZZLE IS POSSIBLE ESPECIALLY OVER NORTHERN
REACHES OF THE SAGINAW VALLEY AND THUMB WHERE TEMPERATURES WILL WARM
ABOVE FREEZING LAST...BUT IT IS NOT LIKELY TO BE TOO IMPACTFUL GIVEN
RESIDUAL MOISTURE AND SALT ON THE ROADS.
FRIDAY...UPPER WAVE TAKES ON A NEGATIVE TILT AS IT LIFTS FROM AR TO
OH. SURFACE LOW TO TRACK FROM SOUTHERN WI TO NORTHERN LOWER MI.
THIS WILL PUT SOUTHEAST MICHIGAN SOLIDLY IN THE WARM SECTOR WITH
TEMPS AREAWIDE ABOVE FREEZING BY AROUND 09Z. BEST AXIS OF
MOISTURE/BEST ISENTROPIC LIFT SKIRTS BY TO THE SOUTH AND EAST. AS A
RESULT...MUCH OF THE AREA MAY ACTUALLY STAY MAINLY DRY DURING THE
MORNING HOURS BEFORE LIFT AHEAD OF THE UPPER WAVE/SURFACE FRONT
BOOSTS US TO HIGH-LIKELY POPS BY AFTERNOON. PRECIP MAY END AS SNOW
FRIDAY NIGHT AS COLDER AIR FILTERS IN...BUT AT THAT POINT THE BETTER
MOISTURE/FORCING IS OFF TO THE NORTH AND EAST SO NOT EXPECTING
ANY MEANINGFUL ACCUMULATION. DUE TO PROGRESSIVE NATURE OF
SYSTEM...LOOKING AT 0.10 TO 0.25 INCHES OF RAIN.
SATURDAY...COLDER AIR CONTINUES TO FILTER IN AS CLOSED UPPER LOW
APPROACHES. TEMPERATURES WILL REMAIN STEADY OR DROP A BIT DURING THE
DAY AS 850 MB TEMPS FALL ABOUT 5C. SOME LAKE EFFECT SNOW SHOWER
ACTIVITY MAY BE AROUND BUT LOW INVERSION HEIGHTS LOOK TO LIMIT THE
COVERAGE. CHILLY LOWS IN THE TEENS SATURDAY NIGHT AS CAA CONTINUES.
AS REMNANTS OF THE WEEKEND LOW EXITS SUNDAY...SOME LAKE EFFECT SNOW
LINGERS MAINLY OVER THE THUMB ON MONDAY...OTHERWISE GENERALLY DRY
THROUGH MIDWEEK. FRIGID COLD AIR SETTLES IN ON THE BACKSIDE OF
SUNDAY`S LOW. OVERNIGHT LOWS DROP INTO THE SINGLE DIGITS FOR MONDAY
MORNING ACROSS SOUTHEAST MICHIGAN....WITH AFTERNOON HIGHS ONLY IN
THE TEENS TO LOW TWENTIES. THE FRIGID AIR HANGS OVER THE AREA
THROUGH WEDNESDAY MORNING WITH TEMPS WARMING SLIGHTLY THROUGH THE
REMAINDER OF THE PERIOD. AN UPPER LEVEL LOW BEGINS TO MIGRATE INTO
THE REGION BY WEDNESDAY AFTERNOON AND IS EXPECTED TO BRING IN THE
NEXT POTENTIAL FOR SNOW.
MARINE...
STRONG EASTERLY FLOW NORTH OF A WARM FRONT WILL BRING GUSTS TO NEAR-
GALES FOR SEVERAL HOURS LATE TONIGHT INTO EARLY FRIDAY MORNING
OVERFAR NORTHERN LAKE HURON. AT THIS TIME...INSTABILITY APPEARS
MARGINAL FOR SUSTAINED GALES ALTHOUGH OCCASIONAL GUSTS TO GALES
CANNOT BE RULED OUT. WINDS WILL THEN VEER TO THE SOUTH BEHIND THE
WARM FRONT FOR FRIDAY INTO FRIDAY NIGHT BEFORE A COLD FRONT
TRAVERSES THE WATERS AND NORTHWEST GUSTS TO GALES BECOME ESTABLISHED
OVER MOST OF LAKE HURON FRIDAY NIGHT AND SATURDAY. THE GALE WATCH
REMAINS IN EFFECT FOR THIS PERIOD.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR
LHZ361>363-441-462-463.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
DISCUSSION...DT/DE
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
602 PM EST WED JAN 13 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 450 PM EST WED JAN 13 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW TROF OVER SE CANADA AND
THE ERN CONUS...ANCHORED BY MID/UPPER LEVEL LOW CENTERED IN THE
VCNTY OF JAMES BAY. IN THE NW FLOW...SHORTWAVE DROPPING SE THRU NW
WI HAS GENERATED SOME -SN THAT IS MOVING ACROSS FAR WRN LAKE
SUPERIOR/NW WI AND PORTIONS OF W AND CNTRL UPPER MI. MEANWHILE...
WITH LATEST RAP ANALYSIS SHOWING 850MB TEMPS AROUND -20C OVER LAKE
SUPERIOR...LES CONTINUES AS WELL. BOUNDARY LAYER WINDS BACKED MORE
THAN EXPECTED LAST NIGHT...RESULTING IN THE CONVERGENCE ZONE AND
ASSOCIATED MDT/HVY SNOW BAND OVER WRN LAKE SUPERIOR INTO NW UPPER MI
LIFTING FARTHER N THAN PLANNED. THAT CONVERGENCE ZONE AND HVY SNOW
BAND IS STILL OVER THE LAKE AND KEWEENAW...CURRENTLY BTWN HOUGHTON
AND CALUMET AS OF 21Z.
WITH THE PASSING OF THE AFOREMENTIONED SHORTWAVE...THE CONVERGENCE
ZONE ACROSS THE KEWEENAW HAS BEEN DRIFTING S THIS AFTN. THE
SOUTHWARD DRIFT WILL CONTINUE...BUT THE CONVERGENCE WILL GRADUALLY
WEAKEN AS LOW-LEVEL WIND FIELD DIMINISHES UNDER WEAKENING PRES
GRADIENT ACROSS THE AREA. AS A RESULT...ONGOING HVY SNOW BAND WILL
DRIFT S OVER THE NEXT SEVERAL HRS...BUT OVERALL INTENSITY OF SNOW
WILL DIMINISH WITH TIME. OPTED TO KEEP LES ADVY FOR NRN HOUGHTON
COUNTY GOING UNTIL SCHEDULED EXPIRATION AT 00Z DUE TO HIGH SNOWFALL
RATES LIKELY ON THE ORDER OF 1-2IN/HR. SNOWFALL SHOULD BE LIGHTER BY
THE TIME IT REACHES ONTONAGON COUNTY IN A FEW HRS. MAY SEE A COUPLE
OF INCHES OF SNOW THERE THIS EVENING. TO THE E...SHORTWAVE COMBINED
WITH REFOCUSING OF CONVERGENCE HAS LED TO LES INCREASING IN
ORGANIZATION/INTENSITY OVER ERN LAKE SUPERIOR OVER THE LAST HR OR
SO. LOOKS LIKE THERE WILL BE ENOUGH NORTHERLY WIND PUSH ACROSS THE
LAKE TO SHIFT THE LES BACK INTO THE NE FCST AREA THIS EVENING. HAVE
PAINTED 2-3 INCHES OF SNOW ACCUMULATION NEAR THE SHORE FROM JUST E
OF MUNISING EASTWARD. ELSEWHERE...-SN/FLURRIES WILL END IN THE NEXT
FEW HRS...AND MAY SEE SOME CLEARING AWAY FROM DIMINISHING LES.
INTERIOR CNTRL HAS BEST CHC OF SEEING AT LEAST SOME PARTIAL CLEARING
FOR A WHILE. LOWERED TEMPS TOWARD THE LOWER END OF AVBL GUIDANCE
(BIAS CORRECTED CANADIAN MODELS)...RESULTING IN MINS A FEW DEGREES
BLO 0F. WITH LIGHT/CALM WINDS...WOULDN`T TAKE MUCH CLEARING OR A
VERY LONG DURATION OF MOSTLY CLEAR TO SEE TEMPS PLUNGE TO -10 TO
-15F OR LWR IN TRADITIONAL COLD SPOTS.
ON THU...ATTENTION TURNS TO SHORTWAVE TROF MOVING OUT OVER THE
NRN/CNTRL PLAINS. IN RESPONSE...WAA/ISENTROPIC ASCENT REGIME
DEVELOPS DOWNSTREAM INTO THE UPPER GREAT LAKES AS SHOWN BEST ON 285K
AND ESPECIALLY 290K SFC. WITH ADDITION TO SOME UPPER DIVERGENCE
PROVIDED BY THE RIGHT ENTRANCE OF UPPER JET AS WELL AS LOW/MID LEVEL
FGEN...EXPECT A BAND OF -SN TO STREAK OUT ACROSS THE NRN PLAINS INTO
THE UPPER GREAT LAKES...AFFECTING UPPER MI MAINLY IN THE AFTN HRS.
12Z CANADIAN MODELS/GFS AND ECMWF WERE IN VERY GOOD AGREEMENT ON
THIS SCENARIO. 12Z NAM WAS MUCH SLOWER IN NE PROGRESS OF PCPN...AND
THE NCEP HIGH RES WRF-NMM WAS A COMPLETE OUTLIER IN ONLY BRUSHING
THE FAR SCNTRL FCST AREA WITH PCPN THU NIGHT. 18Z NAM CAME IN LINE
WITH THE GFS/ECMWF/CANADIAN MODELS WHICH WERE USED AS THE BASIS FOR
FCST. RAISED POPS INTO THE LIKELY RANGE FOR AT LEAST A TIME FOR
NEARLY ALL OF THE FCST AREA THU AFTN. ALTHOUGH 290K SFC SHOWS MIXING
RATIOS OF UP TO 3G/KG AVBL...ASCENT IS NOT ESPECIALLY STRONG AND
SNOW TO WATER RATIOS WILL BE ON THE ORDER OF 15-1. FOR NOW...EXPECT
SNOW ACCUMULATIONS TO BE AROUND 1 INCH W AND ONE-HALF INCH E THU
AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM EST WED JAN 13 2016
...WIDESPREAD SNOW THU NIGHT INTO FRI WITH N/NW FLOW LAKE EFFECT
INTO THE WEEKEND...
TROUGHING ALOFT OVER EAST HALF OF CANADA WITH ADDITIONAL TROUGHING
EXPANDING FM CENTRAL CONUS TO EASTERN CONUS THIS WEEKEND. COLDER
CONDITIONS SHOULD MODERATE EARLY NEXT WEEK AS TROUGH AXIS MOVES TO
EASTERN CANADA AND HEIGHTS BEGIN RISING FM WESTERN CONUS TO GREAT
LAKES.
SHORTWAVE TROUGH CROSSING THE CENTRAL PLAINS ON THU NIGHT ALONG WITH
WEAKER LOW PRESSURE SYSTEM AROUND 1000MB WILL SPREAD LIGHT SNOW FM
NORTHERN MN INTO NORTHERN WI/UPPER MICHIGAN DUE TO ISENTROPIC ASCENT
AND WARM AIR ADVECTION WELL TO NORTH OF SFC WARM FRONT FM UPPER
MISSISSIPPI RIVER VALLEY TO LOWER GREAT LAKES. SNOW MAY BE ENHANCED
BY RIGHT ENTRANCE FORCING FM JET STREAK FM NW ONTARIO TO NEW ENGLAND.
MOST PERSISTENT SNOW FM THE SYSTEM ON THU NIGHT WILL BE OVER
KEWEENAW AND LAKE SUPERIOR. EASTERLY WINDS AHEAD OF APPROACHING SFC
LOW AND H85 TEMPS DOWN NEAR -10C WILL RESULT IN LAKE ENAHANCEMENT.
DGZ IS NARROW AND QUITE ELEVATED ABOVE H7 SO SLR/S AT LEAST FOR THU
NIGHT SHOULD HOLD IN THE 10-15:1 RANGE INSTEAD IN THE FLUFFIER 20:1
RANGE THAT WILL MOVE IN FOR FRI AND BEYOND.
BY FRI MORNING TROUGH ALOFT WILL BE ENTERING WESTERN GREAT LAKES
WHILE SFC LOW DEEPENS TO AROUND 997MB OVER NORTHERN LK MICHIGAN. LOW
CONTINUES TO DEEPEN TO 992MB BY FRI EVENING OVER NORTHERN LK
HURON/GEORGIAN BAY. THOUGH LARGER SCALE FORCING FM THE SHORTWAVE IN
TERMS OF DEEP LAYER Q-VECTOR CONVERGENCE DIMINISHES FROM WEST TO
EAST ON FRI...THE SHORTWAVE TROUGH/LOWER HEIGHTS IN THE VCNTY AND
WELL DEVELOPED COLD CONVEYOR BELT OF DEEPER MOISTURE THROUGH H7/H85-
H7 FRONTOGENESIS ACROSS MUCH OF NORTH HALF OF UPPER MICHIGAN SHOULD
KEEP LIGHT SNOW GOING OVER MOST OF CWA. SNOW WILL FALL MODERATE TO
POSSIBLY HEAVY NEAR LK SUPERIOR DUE TO LAKE ENHANCEMENT AND UPSLOPE
LIFT AS CYCLONIC NORTH/NORTHEAST WINDS ON BACK SIDE OF DEEPENING LOW
DRAW COLDER AIR INTO REGION WITH H85 TEMPS DROPPING BLO -10C.
PRELIMINARY INDICATIONS SUGGEST ADVISORIES WOULD BE NEEDED THU
NIGHT...ESPECIALLY OVER THE KEWEENAW WHERE MORE PERSISTENT SYNOPTIC
SNOW AND LAKE ENHANCEMENT OCCURS...THEN ON FRI/FRI NIGHT FOR WESTERN
AND NORTH CENTRAL UPPER MICHIGAN FOR THE LAKE ENHANCED SNOW.
SNOWFALL FOR ALL OF THESE AREAS MAY REACH THE 6 TO 8 INCH RANGE FOR
24 HOURS THU NIGHT THROUGH FRI. GUSTY WINDS WILL ALSO RESULT IN
BLSN...ESPECIALLY NEAR LK SUPERIOR ON FRI. WILL CONTINUE TO MENTION
IN THE HAZARDOUS WEATHER OUTLOOK.
INTO THE WEEKEND...PERSISTENCE WILL BE THE STORY. COLD AIR CONTINUES
TO FILTER FM CENTRAL CANADA ACROSS WESTERN GREAT LAKES. H85 TEMPS
SHOULD FALL BLO -20C ON SAT AND MAYBE AS LOW AS -24C ON SUN. AT THE
SFC...SHOULD SEE TEMPS IN THE 20S ON FRI FALL OFF INTO THE TEENS FRI
NIGHT INTO SAT THEN TUMBLE BACK DOWN INTO THE SINGLE DIGITS ABOVE
ZERO BY LATE SAT AFTN AND DOWN BLO ZERO SAT NIGHT...AT LEAST FOR THE
WEST INTERIOR. READINGS WILL STRUGGLE TO RISE ABOVE ZERO OVER FAR
WEST ON SUN. OVERALL THE AIRMASS OVER THE AREA WILL BE MODIFIED BY
LAKE SUPERIOR SINCE SFC RIDGE STAYS WELL TO THE WEST FM NORTHERN
CANADA TO THE NORTHERN PLAINS WHILE STRONG SFC LOW AFFECTS EAST
COAST. LAKE INDUCED TROUGH IS EXPECTED TO LINGER ACROSS MUCH OF THE
GREAT LAKES...REINFORCED BY STRONGER UPPER LOW DIVING ACROSS THE
GREAT LAKES WHICH WILL INTENSIFY THE BROAD TROUGHING ACROSS THE
GREAT LAKES. PREVIOUS SHIFT HAD LIKELY POPS FOR THE LAKE EFFECT
THROUGH THE WEEKEND FOR AREAS FAVORED BY NW WINDS. BASED ON LATEST
MODELS SAW NO REASON TO STRAY FM THOSE HIGHER POPS COMPARED TO LOWER
POPS THAT CONSENSUS OF THE MODELS GAVE. PURE LAKE EFFECT SETUP IS
TYPICALLY A TIME WHERE CONSENSUS POPS FM THE COARSER MODELS WILL
FALL SHORT.
COLD PATTERN WITH NW FLOW LAKE EFFECT BEGINS TO BREAK DOWN EARLY
NEXT WEEK. KEPT HIGHER POPS FOR AREAS FAVORED BY NW WINDS THROUGH
MON AND MON NIGHT THEN SHIFTED BACK TO CONSENSUS POPS AS TROUGHING
BEGINS TO RELAX. OVERALL LOOKS LIKE WARMING TREND WILL START UP OR
AT LEAST TEMPS WILL PUSH UP TO NEAR NORMAL. THOUGH LAKE EFFECT WILL
BE ON THE DECLINE...MAY BE WEAK WAVE IN FLATTENING FLOW ALOFT THAT
WOULD BRING SWATH OF LGT SNOW TO UPPER GREAT LAKES BY NEXT WED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 602 PM EST WED JAN 13 2016
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO AFFECT KCMX UNTIL WINDS
BECOME LIGHT/VRBL LATE TONIGHT...BRINGING AN END TO THE SNOW
SHOWERS. IN GENERAL...IFR CONDITIONS WILL PREVAIL AT KCMX UNTIL LATE
TONIGHT. HOWEVER...TYPICAL FOR LAKE EFFECT...CONDITIONS WILL BE
VARIABLE. EXPECT SOME PERIODS OF MVFR AND LIFR AS WELL. AFTER THE
SNOW SHOWERS END...MVFR CIGS WILL LIKELY PERSIST AT KCMX INTO THU
AFTERNOON. AT KIWD...MVFR CONDITIONS SHOULD GENERALLY PREVAIL THRU
THE FCST PERIOD. AT KSAW...VFR CONDITIONS SHOULD PREVAIL THRU MOST
OF THE FCST PERIOD. BY LATE THU AFTERNOON...LIGHT SNOW MOVES IN WITH
THE NEXT SYSTEM AND CONDITIONS WILL DETERIORATE TO IFR AT ALL SITES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST WED JAN 13 2016
NO GALES ARE EXPECTED THRU THIS WEEKEND. MUCH OF THE TIME...WINDS
WILL BE IN THE 15-25KT OR 20-30KT RANGE. WINDS WILL BE LIGHTEST LATE
TONIGHT/THU MORNING...MOSTLY UNDER 15KT. A SURGE OF ARCTIC AIR THIS
WEEKEND WILL BRING A RETURN OF MORE SIGNIFICANT FREEZING SPRAY AS
WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
450 PM EST WED JAN 13 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 450 PM EST WED JAN 13 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW TROF OVER SE CANADA AND
THE ERN CONUS...ANCHORED BY MID/UPPER LEVEL LOW CENTERED IN THE
VCNTY OF JAMES BAY. IN THE NW FLOW...SHORTWAVE DROPPING SE THRU NW
WI HAS GENERATED SOME -SN THAT IS MOVING ACROSS FAR WRN LAKE
SUPERIOR/NW WI AND PORTIONS OF W AND CNTRL UPPER MI. MEANWHILE...
WITH LATEST RAP ANALYSIS SHOWING 850MB TEMPS AROUND -20C OVER LAKE
SUPERIOR...LES CONTINUES AS WELL. BOUNDARY LAYER WINDS BACKED MORE
THAN EXPECTED LAST NIGHT...RESULTING IN THE CONVERGENCE ZONE AND
ASSOCIATED MDT/HVY SNOW BAND OVER WRN LAKE SUPERIOR INTO NW UPPER MI
LIFTING FARTHER N THAN PLANNED. THAT CONVERGENCE ZONE AND HVY SNOW
BAND IS STILL OVER THE LAKE AND KEWEENAW...CURRENTLY BTWN HOUGHTON
AND CALUMET AS OF 21Z.
WITH THE PASSING OF THE AFOREMENTIONED SHORTWAVE...THE CONVERGENCE
ZONE ACROSS THE KEWEENAW HAS BEEN DRIFTING S THIS AFTN. THE
SOUTHWARD DRIFT WILL CONTINUE...BUT THE CONVERGENCE WILL GRADUALLY
WEAKEN AS LOW-LEVEL WIND FIELD DIMINISHES UNDER WEAKENING PRES
GRADIENT ACROSS THE AREA. AS A RESULT...ONGOING HVY SNOW BAND WILL
DRIFT S OVER THE NEXT SEVERAL HRS...BUT OVERALL INTENSITY OF SNOW
WILL DIMINISH WITH TIME. OPTED TO KEEP LES ADVY FOR NRN HOUGHTON
COUNTY GOING UNTIL SCHEDULED EXPIRATION AT 00Z DUE TO HIGH SNOWFALL
RATES LIKELY ON THE ORDER OF 1-2IN/HR. SNOWFALL SHOULD BE LIGHTER BY
THE TIME IT REACHES ONTONAGON COUNTY IN A FEW HRS. MAY SEE A COUPLE
OF INCHES OF SNOW THERE THIS EVENING. TO THE E...SHORTWAVE COMBINED
WITH REFOCUSING OF CONVERGENCE HAS LED TO LES INCREASING IN
ORGANIZATION/INTENSITY OVER ERN LAKE SUPERIOR OVER THE LAST HR OR
SO. LOOKS LIKE THERE WILL BE ENOUGH NORTHERLY WIND PUSH ACROSS THE
LAKE TO SHIFT THE LES BACK INTO THE NE FCST AREA THIS EVENING. HAVE
PAINTED 2-3 INCHES OF SNOW ACCUMULATION NEAR THE SHORE FROM JUST E
OF MUNISING EASTWARD. ELSEWHERE...-SN/FLURRIES WILL END IN THE NEXT
FEW HRS...AND MAY SEE SOME CLEARING AWAY FROM DIMINISHING LES.
INTERIOR CNTRL HAS BEST CHC OF SEEING AT LEAST SOME PARTIAL CLEARING
FOR A WHILE. LOWERED TEMPS TOWARD THE LOWER END OF AVBL GUIDANCE
(BIAS CORRECTED CANADIAN MODELS)...RESULTING IN MINS A FEW DEGREES
BLO 0F. WITH LIGHT/CALM WINDS...WOULDN`T TAKE MUCH CLEARING OR A
VERY LONG DURATION OF MOSTLY CLEAR TO SEE TEMPS PLUNGE TO -10 TO
-15F OR LWR IN TRADITIONAL COLD SPOTS.
ON THU...ATTENTION TURNS TO SHORTWAVE TROF MOVING OUT OVER THE
NRN/CNTRL PLAINS. IN RESPONSE...WAA/ISENTROPIC ASCENT REGIME
DEVELOPS DOWNSTREAM INTO THE UPPER GREAT LAKES AS SHOWN BEST ON 285K
AND ESPECIALLY 290K SFC. WITH ADDITION TO SOME UPPER DIVERGENCE
PROVIDED BY THE RIGHT ENTRANCE OF UPPER JET AS WELL AS LOW/MID LEVEL
FGEN...EXPECT A BAND OF -SN TO STREAK OUT ACROSS THE NRN PLAINS INTO
THE UPPER GREAT LAKES...AFFECTING UPPER MI MAINLY IN THE AFTN HRS.
12Z CANADIAN MODELS/GFS AND ECMWF WERE IN VERY GOOD AGREEMENT ON
THIS SCENARIO. 12Z NAM WAS MUCH SLOWER IN NE PROGRESS OF PCPN...AND
THE NCEP HIGH RES WRF-NMM WAS A COMPLETE OUTLIER IN ONLY BRUSHING
THE FAR SCNTRL FCST AREA WITH PCPN THU NIGHT. 18Z NAM CAME IN LINE
WITH THE GFS/ECMWF/CANADIAN MODELS WHICH WERE USED AS THE BASIS FOR
FCST. RAISED POPS INTO THE LIKELY RANGE FOR AT LEAST A TIME FOR
NEARLY ALL OF THE FCST AREA THU AFTN. ALTHOUGH 290K SFC SHOWS MIXING
RATIOS OF UP TO 3G/KG AVBL...ASCENT IS NOT ESPECIALLY STRONG AND
SNOW TO WATER RATIOS WILL BE ON THE ORDER OF 15-1. FOR NOW...EXPECT
SNOW ACCUMULATIONS TO BE AROUND 1 INCH W AND ONE-HALF INCH E THU
AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM EST WED JAN 13 2016
...WIDESPREAD SNOW THU NIGHT INTO FRI WITH N/NW FLOW LAKE EFFECT
INTO THE WEEKEND...
TROUGHING ALOFT OVER EAST HALF OF CANADA WITH ADDITIONAL TROUGHING
EXPANDING FM CENTRAL CONUS TO EASTERN CONUS THIS WEEKEND. COLDER
CONDITIONS SHOULD MODERATE EARLY NEXT WEEK AS TROUGH AXIS MOVES TO
EASTERN CANADA AND HEIGHTS BEGIN RISING FM WESTERN CONUS TO GREAT
LAKES.
SHORTWAVE TROUGH CROSSING THE CENTRAL PLAINS ON THU NIGHT ALONG WITH
WEAKER LOW PRESSURE SYSTEM AROUND 1000MB WILL SPREAD LIGHT SNOW FM
NORTHERN MN INTO NORTHERN WI/UPPER MICHIGAN DUE TO ISENTROPIC ASCENT
AND WARM AIR ADVECTION WELL TO NORTH OF SFC WARM FRONT FM UPPER
MISSISSIPPI RIVER VALLEY TO LOWER GREAT LAKES. SNOW MAY BE ENHANCED
BY RIGHT ENTRANCE FORCING FM JET STREAK FM NW ONTARIO TO NEW ENGLAND.
MOST PERSISTENT SNOW FM THE SYSTEM ON THU NIGHT WILL BE OVER
KEWEENAW AND LAKE SUPERIOR. EASTERLY WINDS AHEAD OF APPROACHING SFC
LOW AND H85 TEMPS DOWN NEAR -10C WILL RESULT IN LAKE ENAHANCEMENT.
DGZ IS NARROW AND QUITE ELEVATED ABOVE H7 SO SLR/S AT LEAST FOR THU
NIGHT SHOULD HOLD IN THE 10-15:1 RANGE INSTEAD IN THE FLUFFIER 20:1
RANGE THAT WILL MOVE IN FOR FRI AND BEYOND.
BY FRI MORNING TROUGH ALOFT WILL BE ENTERING WESTERN GREAT LAKES
WHILE SFC LOW DEEPENS TO AROUND 997MB OVER NORTHERN LK MICHIGAN. LOW
CONTINUES TO DEEPEN TO 992MB BY FRI EVENING OVER NORTHERN LK
HURON/GEORGIAN BAY. THOUGH LARGER SCALE FORCING FM THE SHORTWAVE IN
TERMS OF DEEP LAYER Q-VECTOR CONVERGENCE DIMINISHES FROM WEST TO
EAST ON FRI...THE SHORTWAVE TROUGH/LOWER HEIGHTS IN THE VCNTY AND
WELL DEVELOPED COLD CONVEYOR BELT OF DEEPER MOISTURE THROUGH H7/H85-
H7 FRONTOGENESIS ACROSS MUCH OF NORTH HALF OF UPPER MICHIGAN SHOULD
KEEP LIGHT SNOW GOING OVER MOST OF CWA. SNOW WILL FALL MODERATE TO
POSSIBLY HEAVY NEAR LK SUPERIOR DUE TO LAKE ENHANCEMENT AND UPSLOPE
LIFT AS CYCLONIC NORTH/NORTHEAST WINDS ON BACK SIDE OF DEEPENING LOW
DRAW COLDER AIR INTO REGION WITH H85 TEMPS DROPPING BLO -10C.
PRELIMINARY INDICATIONS SUGGEST ADVISORIES WOULD BE NEEDED THU
NIGHT...ESPECIALLY OVER THE KEWEENAW WHERE MORE PERSISTENT SYNOPTIC
SNOW AND LAKE ENHANCEMENT OCCURS...THEN ON FRI/FRI NIGHT FOR WESTERN
AND NORTH CENTRAL UPPER MICHIGAN FOR THE LAKE ENHANCED SNOW.
SNOWFALL FOR ALL OF THESE AREAS MAY REACH THE 6 TO 8 INCH RANGE FOR
24 HOURS THU NIGHT THROUGH FRI. GUSTY WINDS WILL ALSO RESULT IN
BLSN...ESPECIALLY NEAR LK SUPERIOR ON FRI. WILL CONTINUE TO MENTION
IN THE HAZARDOUS WEATHER OUTLOOK.
INTO THE WEEKEND...PERSISTENCE WILL BE THE STORY. COLD AIR CONTINUES
TO FILTER FM CENTRAL CANADA ACROSS WESTERN GREAT LAKES. H85 TEMPS
SHOULD FALL BLO -20C ON SAT AND MAYBE AS LOW AS -24C ON SUN. AT THE
SFC...SHOULD SEE TEMPS IN THE 20S ON FRI FALL OFF INTO THE TEENS FRI
NIGHT INTO SAT THEN TUMBLE BACK DOWN INTO THE SINGLE DIGITS ABOVE
ZERO BY LATE SAT AFTN AND DOWN BLO ZERO SAT NIGHT...AT LEAST FOR THE
WEST INTERIOR. READINGS WILL STRUGGLE TO RISE ABOVE ZERO OVER FAR
WEST ON SUN. OVERALL THE AIRMASS OVER THE AREA WILL BE MODIFIED BY
LAKE SUPERIOR SINCE SFC RIDGE STAYS WELL TO THE WEST FM NORTHERN
CANADA TO THE NORTHERN PLAINS WHILE STRONG SFC LOW AFFECTS EAST
COAST. LAKE INDUCED TROUGH IS EXPECTED TO LINGER ACROSS MUCH OF THE
GREAT LAKES...REINFORCED BY STRONGER UPPER LOW DIVING ACROSS THE
GREAT LAKES WHICH WILL INTENSIFY THE BROAD TROUGHING ACROSS THE
GREAT LAKES. PREVIOUS SHIFT HAD LIKELY POPS FOR THE LAKE EFFECT
THROUGH THE WEEKEND FOR AREAS FAVORED BY NW WINDS. BASED ON LATEST
MODELS SAW NO REASON TO STRAY FM THOSE HIGHER POPS COMPARED TO LOWER
POPS THAT CONSENSUS OF THE MODELS GAVE. PURE LAKE EFFECT SETUP IS
TYPICALLY A TIME WHERE CONSENSUS POPS FM THE COARSER MODELS WILL
FALL SHORT.
COLD PATTERN WITH NW FLOW LAKE EFFECT BEGINS TO BREAK DOWN EARLY
NEXT WEEK. KEPT HIGHER POPS FOR AREAS FAVORED BY NW WINDS THROUGH
MON AND MON NIGHT THEN SHIFTED BACK TO CONSENSUS POPS AS TROUGHING
BEGINS TO RELAX. OVERALL LOOKS LIKE WARMING TREND WILL START UP OR
AT LEAST TEMPS WILL PUSH UP TO NEAR NORMAL. THOUGH LAKE EFFECT WILL
BE ON THE DECLINE...MAY BE WEAK WAVE IN FLATTENING FLOW ALOFT THAT
WOULD BRING SWATH OF LGT SNOW TO UPPER GREAT LAKES BY NEXT WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 102 PM EST WED JAN 13 2016
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TO AFFECT KCMX UNTIL WINDS
BECOME LIGHT/VRBL LATE TONIGHT...BRINGING AN END TO THE SNOW
SHOWERS. IN GENERAL...IFR CONDITIONS WILL PREVAIL AT KCMX UNTIL LATE
TONIGHT. HOWEVER...TYPICAL FOR LAKE EFFECT...CONDITIONS WILL BE
VARIABLE. EXPECT SOME PERIODS OF MVFR AND LIFR AS WELL. AFTER THE
SNOW SHOWERS END...MVFR CIGS WILL LIKELY PERSIST AT KCMX THRU THU
MORNING. AT KIWD...MVFR CONDITIONS SHOULD GENERALLY PREVAIL THRU THE
FCST PERIOD. DISTURBANCE PASSING THRU THE AREA THIS AFTN WILL BRING
SOME -SN THAT MAY REDUCE VIS TO IFR AT TIMES. AT KSAW...VFR
CONDITIONS SHOULD PREVAIL THRU THE FCST PERIOD. SOME FLURRIES/-SN
WILL OCCUR THIS AFTN...AND NOT OUT OF THE QUESTION THAT CONDITIONS
COULD BRIEFLY FALL TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST WED JAN 13 2016
NO GALES ARE EXPECTED THRU THIS WEEKEND. MUCH OF THE TIME...WINDS
WILL BE IN THE 15-25KT OR 20-30KT RANGE. WINDS WILL BE LIGHTEST LATE
TONIGHT/THU MORNING...MOSTLY UNDER 15KT. A SURGE OF ARCTIC AIR THIS
WEEKEND WILL BRING A RETURN OF MORE SIGNIFICANT FREEZING SPRAY AS
WELL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
342 PM EST WED JAN 13 2016
.DISCUSSION...
WIDESPREAD LIGHT SNOW IS ONGOING FROM MINNESOTA TO LOWER MICHIGAN AT
PRESS TIME IN ASSOCIATION WITH A COUPLE OF WEAK SHORTWAVES THAT ARE
BEING STEERED SOUTHEAST ACROSS THE GREAT LAKES AT PRESS TIME. THE
FIRST WAVE IN THE SEQUENCE HAS ELICITED A HEALTHY RESPONSE OF WARM
ADVECTION ALOFT AND A 40+KT LLJ THAT IS MODELED TO GRADUALLY
STRENGTHEN THROUGH THIS EVENING. THIS WILL PROVIDE A FOCUS FOR LIGHT
TO OCCASIONALLY MODERATE SNOWFALL MAINLY SOUTH OF THE M59 CORRIDOR
FOR THE NEXT FEW HOURS. THE SECOND WAVE IS EMBEDDED WITHIN THE LEFT
EXIT OF THE JET CENTERED OVER NORTHERN MINNESOTA AND WILL TRAIL THE
LEAD WAVE BY ONLY A FEW HOURS. WEAK DYNAMIC FORCING WILL CENTER
FURTHER NORTH POST-00Z AS MOIST ISENTROPIC ASCENT PROVIDES THE
PRIMARY FORCING THROUGH 03-04Z. THE CEILING ON AMOUNTS IS QUITE LOW
AS OVERALL PERIOD OF SNOW WILL BE SHORT LIVED...MAINLY AN INCH OR
LESS. HOWEVER, THERE IS SOME MINOR OVERACHIEVING POTENTIAL GIVEN A
FAVORABLE THERMODYNAMIC PROFILE FEATURING A SFC-650MB DGZ THAT
IS SHOWN BY THE RAP TO SUPERSATURATED UP TO 110%+ WRT ICE AT TIMES.
SECOND CONCERN WILL SHOW ITSELF IN THE NEXT HOUR OR TWO, AND THAT IS
THE POTENTIAL FOR LAKE EFFECT TO BECOME ESTABLISHED OVER MIDLAND/BAY
COUNTIES WITHIN FAVORABLY UNSTABLE LAKE MICHIGAN PLUME. MADE NO
CHANGES TO THE AFTERNOON UPDATE WHICH CARRIED AMOUNTS OF AROUND 2"
HERE. BACKING LOW-LEVEL FLOW IN THE 0-1KM LAYER WILL QUICKLY END ANY
LES POTENTIAL AFTER 00Z. WARMING OF THE COLUMN, INCLUDING SFC TEMPS
RISING INTO THE LOW/MID 20S, WILL LIFT THE EFFECTIVE DGZ INTO THE
DRY LAYER ALOFT AND END ANY LINGERING FLURRY POTENTIAL BY MORNING.
ATTENTION THEN TURNS TO THE LATE WEEK SYSTEM WHICH WILL TAKE PLACE
IN TWO PHASES. THE FIRST WILL BE ON THURSDAY WHEN THE DEPARTURE OF
TONIGHT`S TROUGH AXIS ALLOW THE AFOREMENTIONED JET CENTERED OVER
MINNESOTA TO ALIGN ZONALLY AS UPSTREAM RIDGING BUILDS IN ADVANCE OF
ENERGY EMERGING OVER THE FRONT RANGE OF THE ROCKIES. THIS WILL FORCE
A PERIOD OF PROLONGED WAA/ISENTROPIC ASCENT FUELED BY RIGHT ENTRANCE
DYNAMICS THURSDAY INTO THURSDAY NIGHT. MARGINALLY FAVORABLE
MICROPHYSICS AND GENERALLY WEAK ASCENT WILL FAVOR JUST LIGHT SNOW
ACCUMULATIONS (HALF INCH OR LESS) NORTH OF I-69 DURING THE DAYTIME
HOURS BEFORE MID-LEVEL RIDGING DRIES THE MID AND UPPER LEVELS.
SECOND PHASE OF THE SYSTEM WILL BE THE PASSAGE OF THE LOW OVER
NORTHERN LOWER MICHIGAN THURSDAY NIGHT THROUGH FRIDAY. WITH THE DEEP
SUBSIDENCE-INDUCED DRY LAYER IN PLACE TO BEGIN THURSDAY NIGHT,
DEVELOPING WARM ADVECTION IN THE LOW-LEVELS WILL LIKELY LEAD TO
WIDESPREAD DRIZZLE. UNTIL CONFIDENCE IS HIGHER, INCLUDED A
FLURRIES/DRIZZLE MENTION. HOWEVER, IF UPSTREAM OBSERVATIONS CONFIRM
MODEL SUGGESTIONS OF DRIZZLE POTENTIAL, THE FLURRIES EFFECTIVELY
BECOME THE PLACEHOLDER IN THE FORECAST FOR FREEZING DRIZZLE, WHICH
COULD LAST FOR SEVERAL HOURS NORTH OF M-59.
RAIN ASSOCIATED WITH COLD FROPA WILL SWEEP ACROSS THE CWA ON FRIDAY
AFTERNOON, ALTHOUGH ONGOING PHASING WITH A POTENT PIECE OF
SUBTROPICAL ENERGY OVER THE MID-ATLANTIC DOES YIELD INCREASED
UNCERTAINTY WITH REGARD TO MOISTURE AND TIMING EVEN FOR SOUTHEAST
MICHIGAN ON FRIDAY. TEMPERATURES WILL REMAIN SEASONABLE, RISING INTO
THE 30S AND THEN NEAR 40 ON THURSDAY AND FRIDAY.
A RETURN TO FRIGID TEMPERATURES AND LAKE EFFECT SNOW SHOWER ACTIVITY
IS LIKELY FOR THE WEEKEND. THIS WILL OCCUR AS A CLOSED UPPER LOW AND
ASSOCIATED POCKET OF COLD AIR /-20C AT 850 MB/ MIGRATES ACROSS THE
GREAT LAKES. THE BEST CHANCE FOR SNOW SHOWER ACTIVITY WILL BE
ACCOMPANIED BY LOBES OF VORTICITY ROTATING THROUGH TO ADD SYNOPTIC
SUPPORT TO LAKE EFFECT ACTIVITY...TIMING AT THIS POINT FAVORS
SATURDAY NIGHT AND SUNDAY...ALTHOUGH SNOW SHOWERS WILL LIKELY BE
AROUND IN SOME FASHION THE ENTIRE WEEKEND. NORTHWEST FLOW AND
SURFACE HIGH PRESSURE WILL RESULT IN LESS CLOUDS AND SNOW SHOWERS AS
WELL AS SLIGHTLY MILDER TEMPERATURES TUESDAY AND WEDNESDAY.
&&
.MARINE...
LOW PRESSURE WILL TRACK OVER THE NORTHERN GREAT LAKES
TONIGHT...BRINGING A CHANCE OF SNOW TO THE REGION. A BRIEF BREAK
WILL FOLLOW ON THURSDAY AS HIGH PRESSURE TRIES TO BUILD INTO THE
SOUTHERN GREAT LAKES. THE NEXT LOW PRESSURE SYSTEM ARRIVES FROM THE
WEST ON THURSDAY NIGHT AND FRIDAY. THIS LOW WILL CONTINUE TO DEEPEN
AS IT TRACKS OVER THE GREAT LAKES RESULTING IN INCREASING WINDS ON
FRIDAY NIGHT AND INTO SATURDAY. WIND GUSTS OVER LAKE HURON COULD
REACH GALE CRITERIA AND THEREFORE...A GALE WATCH HAS BEEN ISSUED FOR
THIS TIMEFRAME.
&&
.AVIATION...ISSUED 621 AM EST WED JAN 13 2016
SCATTERED LAKE EFFECT -SHSN WILL BREAK UP THIS MORNING WITHIN SSW
FLOW IN ADVANCE OF NEXT CLIPPER. HOWEVER...LIGHT SNOW WILL SPREAD
INTO TERMINALS WITH THIS NEXT SYSTEM BY 22Z-00Z WITH MVFR CIGS
COMMON AND IFR VSBYS QUITE POSSIBLE DURING A 4-6 HOUR PERIOD OF MOST
PERSISTENT SNOW THIS EVENING. GENERALLY MVFR CIGS WILL PERSIST INTO
TONIGHT EVEN AFTER MAIN LIGHT SNOW EXITS TO THE EAST AS -SHSN LINGER.
SW FLOW IN THE 10-12 KNOT RANGE WILL PERSIST THROUGHOUT THE FORECAST.
AT DTW...TERMINAL WILL REMAIN ON SOUTHERN EDGE OF LES -SHSN EARLY IN
THE FORECAST WITH LIGHT SNOW SPREADING BACK INTO AREA 23Z OR SO.
MVFR/LOWER VFR CIGS EARLY WILL EDGE BACK TO MVFR WITH CLIPPER THIS
EVENING WITH IFR VSBYS AT TIMES IN THE -SN.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CIGS AOB 5KFT THROUGHOUT THE FORECAST
* HIGH FOR PTYPE OF SNOW
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR
LHZ361>363-441-462-463.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
DISCUSSION...JVC/DT
MARINE.......RK
AVIATION.....DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1221 AM EST WED JAN 13 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 429 PM EST TUE JAN 12 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS CONTINUE A SHOW A TROF
EXTENDING FROM HUDSON BAY INTO THE GREAT LAKES REGION. IN THE WAKE
OF THE VIGOROUS SHORTWAVE THAT IS MOVING THRU THE LWR GREAT LAKES
ATTM...DRIER AIR...SUBSIDENCE AND FALLING INVERSION HEIGHTS (NOW
AROUND 5KFT W AND 7KFT E PER LATEST RAP) HAVE RESULTED IN SOME
DIMINISHING OF LES TODAY...THOUGH SOME MDT SNOW SHOWERS CONTINUE.
INVERSION HEIGHTS REMAIN RELATIVELY STEADY STATE TONIGHT...BUT THERE
ARE SOME AREAS OF CONCERN AS WINDS SLOW BACK. FIRST...OVER THE NE
FCST AREA...STRENGTHENING LAND BREEZES IN CONCERT WITH LARGER SCALE
BACKING WINDS OVER UPPER MI WILL LEAD TO INCREASING LOW-LEVEL
CONVERGENCE FROM ALGER COUNTY INTO NRN LUCE COUNTY. ALONG WITH THE
LONG FETCH...EXPECT 3-5 INCHES OF SNOW IN GENERAL FROM AROUND GRAND
MARAIS E ACROSS NRN LUCE COUNTY. SNOW WILL END IN WRN ALGER COUNTY
TONIGHT AS BANDS SHIFT E UNDER BACKING WINDS. MOST OF THE LES SHOULD
BE OFFSHORE BY SUNRISE...THOUGH SOME LES WILL BRUSH THE SHORELINE
FROM GRAND MARAIS EASTWARD IN THE MORNING. ALGER COUNTY LES ADVY HAS
BEEN EXTENDED TO 12Z WED WITH LUCE ADDED TO THAT.
TO THE W...A TYPICAL CONVERGENCE PATTERN WILL DEVELOP AS BACKING
WINDS AIDED BY LAND BREEZE RESULTS IN WSW WINDS DEVELOPING OVER THE
SRN PART OF WRN LAKE SUPERIOR. MEANWHILE...WINDS REMAIN MORE WNW
BTWN THE KEWEENAW AND ISLE ROYALE. END RESULT IS ENHANCED
CONVERGENCE SETTING UP ACROSS THE MID PORTION OF WRN LAKE
SUPERIOR...AIMED INTO THE FAR NRN PART OF ONTONAGON COUNTY AND INTO
CNTRL HOUGHTON COUNTY...ROUGHLY BTWN TWIN LAKES AND PAINESDALE. HIGH
RES MODEL GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO WITH ONLY
SUBTLE DIFFERENCES IN PLACEMENT OF HEAVIEST QPF. CONVERGENCE BAND
MAY SHIFT N SLIGHTLY DURING THE DAY WED AND AFFECT THE HOUGHTON
AREA. LES WILL BE LIGHT THIS EVENING AS FLOW ADJUSTS OVER WRN LAKE
SUPERIOR. LES SHOULD THEN INCREASE OVERNIGHT THRU WED IN THE
AFORMENTIONED AREA AS THE CONVERGENCE ZONE SETS UP. THERE IS SOME
INDICATION FOR A SLIGHT LIFTING OF THE INVERSION LATE TONIGHT/WED
AND LIFTING OF THE DGZ TO ENCOMPASS MORE OF THE CONVECTIVE
LAYER...ESPECIALLY WED. SO...GREATER SNOW ACCUMULATIONS WILL OCCUR
DURING THE DAY WED. EXPECT GENERALLY 2-4 INCHES OF SNOW
TONIGHT...THEN 3-7 INCHES OF SNOW WED. ADVY WILL ONLY BE CARRIED FOR
NRN HOUGHTON COUNTY WHERE BEST SNOWFALL IS EXPECTED. IF IT LATER
LOOKS LIKE MORE OF NRN ONTONAGON COUNTY MAY BE IMPACTED...ADVY WILL
NEED TO BE EXPANDED.
OTHER POTENTIAL CONCERN IS WIND CHILL HEADLINES IN THE COUNTIES
ALONG THE MI/WI BORDER. WITH MIN TEMPS CURRENTLY EXPECTED AROUND
-10F AND SUSTAINED WINDS LESS THAN 10 MPH...APPARENT TEMPS END UP
JUST SHY OF THE -25F THRESHOLD FOR WIND CHILL ADVY. WILL BE
SOMETHING TO MONITOR DURING THE EVENING IN THE EVENT TEMPS FALL MORE
THAN EXPECTED AND/OR WINDS ARE A BIT STRONGER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 429 PM EST TUE JAN 12 2016
WARMER AIR WILL BE MOVING IN STARTING WEDNESDAY NIGHT. NW FLOW AND
AN ELONGATED SHORTWAVE WILL CONTINUE ALOFT WITH A 300MB JET AROUND
120KTS. THE FOCUS FOR ANY LINGERING MODERATE SNOW SHOWERS WILL BE
OVER THE NW FAVORED WIND SNOW BELTS OF THE KEWEENAW PENINSULA.
ELSEWHERE...MORE OF AN OFFSHORE OR PARALLEL SHORE FLOW IS
ANTICIPATED OVER THE E. ANOTHER 1-2IN OF SNOW WILL BE POSSIBLE FROM
THE PORCUPINE MTNS THROUGH THE TIP OF THE KEWEENAW...AND THEN RIGHT
ALONG THE SHORELINE FROM GRAND MARAIS TO WHITEFISH POINT.
THE 500MB LOW SPINNING OVER W HUDSON BAY WILL BEGIN TO SINK
OVER N MANITOBA. AS A RESULT...LOOK FOR A MORE W FLOW TO TAKE HOLD
OVER THE UPPER GREAT LAKES ON THURSDAY AS A TROUGH EXTENDS S FROM
THE 500MB LOW ALL THE WAY THROUGH THE CENTRAL PLAINS AND DOWN TROUGH
THE GULF OF MEXICO. SYNOPTIC SNOW/SNOW SHOWERS SHOULD WILL RETURN
THURSDAY...AHEAD OF THE COMBINING N LOWS SINKING ACROSS THE N AND
CENTRAL PLAINS. THERE HAS BEEN SOME DIFFERENCES ON THE TRACK OF THIS
LOW OVER THE PAST 24 HOURS. YESTERDAY THEY SHOWED MORE OF A S
TREND...LIKE THE 12Z SREF /OVER E KS/OK AT 06Z FRIDAY/. SINCE THEN
THEY ARE A BIT MORE N INTO IA. EITHER WAY...A PERSISTANT NE-N SFC
FLOW LOOKS TO SET IN ACROSS LAKE SUPERIOR AND UPPER MI FRIDAY
AFTERNOON THROUGH SATURDAY EVENING AS THE SFC LOW EXITS ACROSS THE
LOWER GREAT LAKES. THIS FEATURE LOOKS TO JOIN FORCES WITH ANOTHER
LOW DEEPENING AS IT TRACKS UP THE E SEABOARD SATURDAY. THE RESULT
WILL BE A STEADY TROUGH OVER OUR AREA WITH N-NW FLOW THROUGH TUESDAY
AS A SFC HIGH OVER THE PLAINS SUNDAY NIGHT SLOWLY ATTEMPS TO BUILD
IN OVER THE FIRST HALF OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1220 AM EST WED JAN 13 2016
WINDS CONTINUING TO BACK THRU THE PERIOD SHOULD ALLOW KSAW TO
REMAIN VFR THROUGH MUCH OF PERIOD UNDER A DOWNSLOPE WSW WIND
COMPONENT. AT KIWD...BANDS SHOULD SHIFT N OF THE TERMINAL
OVERNIGHT ALLOWING FOR VFR CONDITIONS TO PREVAIL THIS
MORNING...ALTHOUGH MVFR CLOUDS WILL MOVE BACK IN WED AFTERNOON AS
ANOTHER DISTURBANCE/TROUGH MOVES THROUGH THE REGION. AT
KCMX...-SHSN WILL CONTINUE WITH A WIND TRAJECTORY OFF THE LAKE.
EXPECT IFR CONDITIONS TO MOSTLY PREVAIL...BUT AS IS TYPICAL FOR LAKE
EFFECT...CONDITIONS WILL BE VARIABLE WITH SOME MVFR AND LIFR AT
TIMES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 404 PM EST TUE JAN 12 2016
WINDS WILL RELAX TONIGHT...AND REMAIN UNDER 25KTS THROUGH THROUGH
THURSDAY NIGHT /DOWN TO LESS THAN 15KTS FOR MUCH OF LAKE SUPERIOR
LATE WEDNESDAY NIGHT THROUGH THURSDAY/. HOWEVER...THERE COULD STILL
BE SOME HEAVY FREEZING SPRAY OVER THE E HALF OF LAKE SUPERIOR EARLY
THIS EVENING. LOW PRESSURE ALONG THE S ONTARIO AND QUEBEC BORDER
WILL EXIT NE OF MAINE OVERNIGHT. A TROUGH WILL LINGER OVER LAKE
SUPERIOR AS A RIDGE ACROSS MINNESOTA THIS EVENING SLIDES ACROSS WI
OVERNIGHT...AND THEN TO THE SE STATES WEDNESDAY. EXPECT THE TROUGH
OVER LAKE SUPERIOR TO DEEPEN WEDNESDAY INTO THURSDAY.
TWO AREAS OF LOW PRESSURE OVER N MANITOBA AND THE DAKOTAS THURSDAY
MORNING ARE EXPECTED TO COMBINE AND SHIFT ACROSS THE CENTRAL PLAINS
THURSDAY NIGHT-FRIDAY. NE GUSTS OF 25-30KTS WILL RETURN FRIDAY
AFTERNOON...AND LINGER THROUGH MUCH OF THE PERIOD WHILE TURNING MORE
OUT OF THE N-NNW /ESPECIALLY OVER THE E HALF OF LAKE SUPERIOR/.
THE LOW WILL LIFT NE ACROSS LOWER MI FRIDAY NIGHT AND EXIT
ACROSS N NY SATURDAY NIGHT AS A STRONGER LOW RIDES UP THE E
SEABOARD. LOOK FOR THE LINGERING RIDGE TO WEAKEN ACROSS LAKE
SUPERIOR AS A HIGH PRESSURE SYSTEM MOVES FROM CANADA TO THE N AND
CENTRAL PLAINS SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ006-
007.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
604 PM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 604 PM CST THU JAN 14 2016
WE HAVE MADE A FEW SURGICAL REVISIONS TO THE ADVISORIES IN EFFECT
FOR TONIGHT BASED PRIMARILY ON CURRENT OBSERVATIONAL AND RADAR
TRENDS...WITH A BIT OF HELP FROM THE MASS FIELDS OF THE VERY SHORT
RANGE MODELS. RADAR/SATELLITE/OBJECTIVE ANALYSIS FIELDS FROM THE
SPC AND RAP ALL SUPPORT THAT LATEST GUIDANCE FROM THE
HRRR/DLHWRF/RAP AND NAM THAT THE AXIS OF MAX LARGE SCALE AND
MESOSCALE FGEN FORCING FOR ASCENT ARE CONSOLIDATING WITH ABOUT A
60 MILE WIDE BAND CENTERED FROM NEAR BEMIDJI...TO HIBBING TO
LUTSEN. THE LARGE SCALE FORCING FOR ASCENT IS NOT EXCEPTIONALLY
STRONG..BUT BANDING ON RADAR CLEARLY REVEALS A MESOSCALE FGEN
ENHANCEMENT TO THE LIFT THAT IS GOING ON..WHICH WILL ACT TO RAISE
SNOWFALL RATES A LITTLE BIT. THIS WILL BE ENHANCED FURTHER BY THE
COLD AIRMASS IN PLACE..RESULTING IN SNOW RATIOS OF 14-17 TO 1.
GIVEN THE LOCATION OF THE MAX ASCENT..WE HAVE EXPANDED THE
ADVISORY TO INCLUDE NORTHERN ITASCA COUNTY..AND WE MAY PUSH
ADVISORY THRESHOLDS ACROSS THE FAR SOUTHERN SECTIONS OF
KOOCHICHING/NORTHERN ST. LOUIS COUNTY. CONVERSELY..WE HAVE
CANCELLED THE ADVISORY FOR PINE COUNTY..AS THEY ARE JUST TOO FAR
SOUTH TO GET INTO THE MAIN AREA OF PRECIP UNTIL THE MAIN LOW
FORCES THE FRONTAL BAND OF PRECIP TO COLLAPSE SOUTH. HOWEVER..
THIS WILL NOT OCCUR UNTIL LATE TONIGHT AND WILL ACT TO GREATLY
LIMIT SNOWFALL FROM PINE TO PRICE COUNTIES. ITS NOT INCONCEIVABLE
THAT WE WILL FLIRT WITH WARNING THRESHOLDS OVER PARTS OF THE MN
ARROWHEAD IN THE 5-7 INCH RANGE IN A FEW LOCALES.
ALSO...UPDATED AVIATION DISCUSSION FOR 00Z TAF ISSUANCE BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 400 PM CST THU JAN 14 2016
HAVE RAISED THE ADVISORY FLAG. HAVE REPORTS OF 3 TO 5 INCHES FROM
EASTERN NORTH DAKOTA TO WEST CENTRAL MINNESOTA. THIS AREA OF SNOW
HAS BEEN GRADUALLY SPREADING INTO THE DLH WARNING AREA WHERE
REPORTED AMOUNTS HAVE BEEN AN INCH OR LESS...EXCEPT IN THE FAR
WEST IN THE HEAVIER SNOW AREAS WHERE THE CASS LAKE AREA HAD 3
INCHES. EXPECT THE SNOW TO REMAIN ACROSS THE REGION BUT MAINLY
AROUND THE U. S. HIGHWAY 2 CORRIDOR AND THE INTERSTATE 35
CORRIDOR AND UP ALONG THE NORTH SHORE. AN AREA OF STRONG WARM AIR
ADVECTION COUPLED WITH DEEP FGEN HAS BEEN PRODUCING SNOW IN A WEST
TO EAST BAND ACROSS NORTH CENTRAL MINNESOTA AND FAR NORTHERN
WISCONSIN. EXPECT THIS TREND TO CONTINUE THROUGH LATE AFTERNOON
AND EVENING. AS THE AFTERNOON PROGRESSED HAVE SEE THE SNOW INTO
MORE A DENDRITIC PHASE AS MORE ICE CRYSTALS HAVE BEEN
INCORPORATED INTO THE COLUMN. THIS WILL INCREASE SNOW TOTALS A BIT.
AS THE SURFACE LOW PRESSURE MOVES EAST ACROSS SRN MN AND WI
TONIGHT EAST TO NORTHEAST WINDS WILL INCREASE A BIT AND WITH 8H
TEMPS IN THE -8 TO -12C RANGE DELTA T`S WILL BE IN THE -15C RANGE.
THIS...COMBINED WITH OROGRAPHIC LIFT COULD GIVE A FEW INCHES
ACROSS THE NORTHSHORE. THE LATER TONIGHT WINDS WILL BECOME MORE
NORTHERLY GIVING NORTHERN WISCONSIN A SHOT OF MORE LAKE EFFECT AND
TERRAIN ENHANCED SNOW THAT COULD LAST MOST OF FRIDAY. BY LATE
FRIDAY AFTERNOON THE LOW WILL BE WELL EAST OF THE AREA OVER LOWER
MICHIGAN BUT THE UPPER LEVEL TROF WILL STILL HAVE THE NORTHLAND IN
CYCLONIC FLOW...KEEP CLOUDS OVER THE REGION...AND SNOW OVER NRN
WI.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 400 PM CST THU JAN 14 2016
PRIMARY FORECAST CHALLENGES DURING THE LONG TERM ARE LAKE EFFECT
SNOW POTENTIAL ALONG THE SOUTH SHORE AND ANOTHER ARCTIC OUTBREAK AND
RELATED WIND CHILLS THROUGH THE WEEKEND.
SURFACE LOW PRESSURE WILL BE LOCATED OVER UPPER MICHIGAN AT THE
START OF THE PERIOD...WITH ARCTIC HIGH PRESSURE BUILDING ACROSS THE
NORTHERN PLAINS. NORTHERLY TO WESTERLY WINDS OVER LAKE SUPERIOR AND
COLD TEMPERATURES ALOFT WILL SUPPORT A PROLONGED PERIOD OF LAKE
EFFECT SNOW OVER THE FAVORED AREAS OF NORTHERN BAYFIELD...ASHLAND...
IRON AND PRICE COUNTIES. SNOW TOTALS BETWEEN FRIDAY NIGHT AND MONDAY
MORNING OF 6 TO 8 INCHES ARE POSSIBLE.
THE OTHER CONCERN FOR THE UPCOMING WEEKEND WILL BE THE BITTERLY COLD
TEMPERATURES AND WIND CHILLS. A COLD CORE UPPER LOW WILL ROTATE
SOUTHWARD INTO THE UPPER MIDWEST BEGINNING FRIDAY EVENING AND
CONTINUING THROUGH THE WEEKEND. THE GLOBAL DETERMINISTIC MODELS...
ECMWF/GFS/GEM BRING A CORE OF -25 C TO -30 C 925 MB TEMPERATURES
INTO THE REGION SATURDAY NIGHT. THE COLD AIR ALOFT WILL SLOWLY
MODERATE THROUGH THE WEEKEND AS THE UPPER LOW LINGERS OVER THE AREA.
LOW TEMPERATURES FRIDAY NIGHT WILL RANGE FROM NEAR -20 F IN
NORTHERN MINNESOTA TO NEAR 0 IN NORTHWEST WISCONSIN...WHERE CLOUDS
AND LES WILL LIMIT COOLING. TEMPERATURES ON SATURDAY NIGHT AND SUNDAY
NIGHT WILL BOTTOM OUT IN THE -25 F TO -10 F RANGE. WIDESPREAD
NOCTURNAL WIND CHILLS OF -20 F TO -40 F ARE POSSIBLE THROUGH THE
WEEKEND. WIND CHILL ADVISORIES OR WARNINGS MAY BE NEEDED.
TEMPERATURES MODERATE AS A QUASI-ZONAL FLOW PATTERN DEVELOPS OVER
THE CENTRAL CONUS MONDAY THROUGH WEDNESDAY. A FEW SHORTWAVES WILL
PASS THROUGH THE FLOW AND MAY RESULT IN SCATTERED SNOW SHOWERS.
TIMING THESE FEATURES AND GENERAL POOR AGREEMENT BETWEEN MODELS...
ALONG WITH LOW MOISTURE AVAILABILITY DO NOT SUPPORT EVEN SLIGHT
CHANCE POPS AT THIS TIME. HOWEVER...LAKE EFFECT SNOW SHOWERS WILL BE
POSSIBLE WITH GENERALLY NORTHERLY SURFACE WINDS THROUGH MUCH OF THE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 604 PM CST THU JAN 14 2016
SURFACE LOW WILL MOVE EAST WHILE SLOWLY INTENSIFYING TONIGHT AND
FRIDAY...MOVING FROM THE IA/MN BORDER REGION TO NORTHERN LK
MICHIGAN TOWARD THE END OF THE PERIOD. BAND OF LIGHT TO MODERATE
SNOW WILL SLOWLY PIVOT ACROSS NRN MN TONIGHT AND THEN SHIFT
EASTWARD WITH THE LOW AND DEVELOPING DEFORMATION AXIS ON THE NW
SIDE OF AFOREMENTIONED LOW AFTER MIDNIGHT AND FRI MORNING. MOST
TAF SITES WILL SEE SUSTAINED MVFR CEILINGS AND FLIRT WITH IFR
VISIBILITIES IN SNOW - ESPECIALLY KDLH/KHIB. HOWEVER..SPECIFIC
TIMING CONFIDENCE ON SHORT PERIODS OF LOWERED VSBY AT KDLH IS LOW.
WINDS WILL SLOWLY SHIFT TO THE NORTH TONIGHT AND GRADUALLY
INCREASE DURING THE DAY FRIDAY AS LOW LEVEL COLD ADVECTION
STRENGTHENS
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 14 17 -9 -3 / 90 40 10 0
INL -2 7 -15 -8 / 40 10 10 10
BRD 8 12 -12 -4 / 70 20 0 0
HYR 18 25 -5 1 / 70 60 20 10
ASX 19 25 1 4 / 80 60 40 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL NOON CST FRIDAY FOR WIZ001>004.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ018-
025-026-033>036.
WINTER WEATHER ADVISORY UNTIL NOON CST FRIDAY FOR MNZ012-019>021-
037.
LS...SMALL CRAFT ADVISORY FROM 9 AM TO 10 PM CST FRIDAY FOR LSZ121-
144>148.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 10 PM CST FRIDAY
FOR LSZ140>143.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
859 PM CST THU JAN 14 2016
.UPDATE:
Issued at 847 PM CST Thu Jan 14 2016
Am in the process of updating the forecast for the rest of the
night and into Friday morning. RAP and HRRR have been backing off
precip for the overnight hours with each successive run. Seeing
some 5-7000 ft ceiling developing over eastern KS and western MO,
but no echos on radar yet. It looks like the RAP is hinting that
the warm advection showers ahead of the front will not be as wide
spread as the moisture convergence/warm advection does not appear
to be as strong as previously forecast. The bulk of the precip now
looks to be associated with the actual low level convergence ahead
of the front and energy aloft with the shortwave. Will be backing
off the areal coverage and moving timing later in the night for
the initial showers, and then bringing likely pops up the I-44
corridor from about 11Z to 15-16Z ahead of the front.
Carney
&&
.SHORT TERM: (Tonight through Friday)
Issued at 330 PM CST Thu Jan 14 2016
Still looking at a quick and light rain event for the area tonight
into Friday morning. Not much has changed except the models are a
tad slower with the trends and onset of precipitation with this
system. The short wave now moving into the Plains will amplify as
it moves into the MS Valley tonight and then exit rather quickly
into the OH Valley on Friday afternoon. Moisture is initially a
bit limited this evening, however low level WAA, large scale
forcing for ascent, and moisture will ramp up overnight and this
should lead to increasing coverage of showers with time, beginning
in southwest MO around mid-evening and spreading/developing into
the CWA after midnight. The precipitation should shut down by
early afternoon across the CWA as the short wave and associated
cold front move east. After the mild day today, it will feel
vastly different on Friday, especially in the afternoon with gusty
west-northwest winds contributing to strong CAA and falling
temperatures in the wake of the front.
Glass
.LONG TERM: (Friday Night through Next Thursday)
Issued at 330 PM CST Thu Jan 14 2016
Surface high pressure builds into the area Friday night into
Saturday and conditions are seasonably cold and relatively calm. A
strong upper vortex/trof will dig from east of Lake Winnipeg on
Saturday through the Great Lakes region Saturday and Saturday
night, carving out a long wave trof over the eastern 2/3rds of
the CONUS which will dominate Sunday-Monday. The height falls and
large scale ascent accompanying the upper system and frontogenesis
with a strong secondary cold surge will contribute to a region of
light snow. The best threat at this time will be centered along
and north of I-70 and a 1-2 inch event is possible. POPs are
probably too low but we con`t to increase them with sucessive
forecasts. Strong high pressure builds into the area Sunday
night into Monday as a very cold air mass, the coldest so far this
winter, settles in and brings a winter grip.
The flow aloft flattens after Monday in the wake of the departing
long wave trof in the east and considerable model variability
ensues in the deterministic and ensemble solutions. The ECMWF has
come around to the GFS with another light snow event centered on
Tuesday, however the system is much weaker. Another precipitation
event appears on tap on Thursday however there are large
differences in many details, especially the thermal structure.
Glass
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 546 PM CST Thu Jan 14 2016
An upper level disturbance and cold front will move through our
area late tonight and Friday morning. MVFR cigs will develop and
spread northeastward into the taf sites late tonigt, eventually
dropping into the IFR catagory towards morning. Light rain will
also spread into the area late tonight, mainly impacting the St
Louis metro area. A strong swly low level jet will contribute to
LLWS conditions tonight with swly winds at 1500-2000 feet in
height of 45-50 kts later this evening into the overnight hours.
The rain should shift east of the St Lous metro area by late
morning. Swly surface wind will veer around to a nwly direction
after fropa Friday morning.
Specifics for KSTL: Light rain along with MVFR cigs will spread
into STL late tonight. The ceiling will continue to drop into
the IFR catagory towards early Friday morning. The rain should end
by late Friday morning, with the ceiling lifting back up into the
MVFR catagory by early afternoon. S-swly surface wind will veer
around to a nwly direction Friday morning after fropa, and
strengthen becoming gusty in the afternoon.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1244 PM EST WED JAN 13 2016
.SYNOPSIS...
HEAVY LAKE EFFECT SNOW WILL CONTINUE TODAY IN PARTS OF CENTRAL NEW
YORK DOWNWIND OF LAKE ONTARIO...ESPECIALLY THE SYRACUSE METRO
AREA AND NORTHERN ONEIDA COUNTY. THE REST OF THE REGION WILL BE
COLD AND BRISK WITH SCATTERED SNOW SHOWERS OR FLURRIES FROM A LAKE
ERIE SNOW BAND. LIGHT SNOW IS POSSIBLE WITH ANOTHER CLIPPER SYSTEM
LATE TONIGHT INTO THURSDAY. A STRONGER SYSTEM IS EXPECTED FRIDAY
NIGHT THROUGH SATURDAY NIGHT WITH A MIX OF RAIN AND SNOW POSSIBLE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1110 AM UPDATE...
MADE SOME ADJUSTMENT TO THE FORECAST TO ACCOUNT FOR TRENDS ON
RADAR AND WIND FLOW FOR THE LAKE EFFECT BANDS FROM BOTH ERIE AND
ONTARIO. HEAVY SNOW WILL CONTINUE AS THE RADAR SHOWED
INTENSIFICATION WITH THE ONTARIO BAND THROUGH THE NEXT FEW HOURS
WITH A SLIGHT BUT STEADY NUDGE NORTH STARTING AROUND 1PM. LAKE
ERIE BAND DROPPING LIGHT SNOW WELL INTO CNY AND EVEN FAR NE PA
BEFORE DROPPING OFF NEAR I-81. HAVE ADJUSTED CLOUD COVER AND POPS
DOWN IN AREAS IN BETWEEN THE BANDS.
410 AM UPDATE...
HEAVY LAKE EFFECT SNOW IS ONGOING IN PARTS OF CENTRAL NEW YORK. AS
IS TYPICAL...THE BAND /OR AT TIMES BANDS/ IS FLUCTUATING IN
PLACEMENT BY THE HOUR. THIS IS OCCURRING WITH EACH PASSING RIPPLE
EMBEDDED WITHIN THE FLOW ON THE BACK SIDE OF THE UPPER TROUGH THAT
IS GRADUALLY LIFTING NORTHEAST. 1 TO 2 INCH PER HOUR SNOWFALL
RATES WILL CONTINUE WITHIN THE HEAVIEST BANDS EARLY THIS
MORNING...NOW SLAMMING THE SYRACUSE METRO AREA EAST TO ABOUT
VERONA...TO SOUTH OF UTICA. LOCAL CONDITIONS WILL VARY WIDELY WITH
ABRUPT NEAR WHITE-OUT CONDITIONS POSSIBLE AT TIMES. WEST WIND WILL
ALSO STILL GUST TO 30 MPH THROUGH THE MORNING WHICH WILL TEND TO
DRIFT THE DRY AND FLUFFY SNOW. THIS WILL MAKE IT A CHALLENGE TO
KEEP ROADS CLEAR...ESPECIALLY NORTH-SOUTH ORIENTED ROUTES.
AN INTERRUPTION IN INTENSITY MAY OCCUR AROUND MID MORNING...BEFORE
THE BAND REINVIGORATES EARLY AFTERNOON WHILE SHIFTING GRADUALLY
NORTH AND CATCHING A LONGER FETCH DOWN THE LENGTH OF LAKE ONTARIO.
THUS FAR...A TOO-FAR-SOUTHWARD BIAS HAS BEEN DEPICTED BY ARW NMM
HRRR AND RUC MODELS...WHICH HAS BEEN OBSERVED TO BE COMMON WITH
LAKE ONTARIO LAKE EFFECT EVENTS IN THE PAST. I HAVE CONTINUED TO
LEAN ON THE CANADIAN AND TO A LESSER DEGREE THE NAM FOR
EXPECTATIONS OF BAND PLACEMENT. THAT BEING SAID...THERE IS SOME
SORT OF SMALL MCV/VORTICITY FEATURE THAT WAS OBSERVED CROSSING
LAKE HURON TO THE ONTARIO PENINSULA...AND NOW GETTING INTO FAR
WESTERN LAKE ONTARIO. I SUSPECT THIS IS WHAT MAY CAUSE THE LAKE
EFFECT TO LOSE A LITTLE ORGANIZATION LATER THIS MORNING...WHICH
THE LATEST 06Z NAM ALSO SEEMS TO BE LATCHING ON.
EARLY THIS AFTERNOON LAKE EFFECT SHOULD BE AGAIN PRETTY STOUT
ALONG THE NY THRUWAY AT FIRST...BUT LIFTING NORTHWARD WITH TIME.
IT SHOULD BE NORTH OF SYRACUSE BY MID AFTERNOON...NORTH OF UTICA
BY MID-TO-LATE AFTERNOON...AND THEN EXIT NORTHERN ONEIDA COUNTY
EARLY EVENING.
FOR THE REST OF THE REGION...GENERALLY JUST A COLD BRISK DAY WITH
SCATTERED SNOW SHOWERS AND FLURRIES...MAINLY TWIN TIERS NORTHWARD.
TEMPERATURES WILL PRETTY MUCH HOLD IN THE UPPER TEENS-LOWER 20S.
LAKE ERIE BANDS WILL AT TIMES EXTEND ACROSS THE CENTRAL TWIN
TIERS TO PROVIDE LIGHT DUSTINGS OF SNOW...WHICH THE WIND WILL
EASILY PICK UP AND BLOW AROUND. THERE COULD BE AN INCH OR TWO
ACCUMULATION ESPECIALLY STEUBEN-YATES- SCHUYLER. T
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
LAKE ONTARIO BAND WILL SHIFT NORTH OF THE AREA THIS EVENING...BUT
ALREADY IN THIS BUSY PATTERN...THE WARM AIR ADVECTION SIDE OF
ANOTHER CLIPPER WILL MOVE IN LATE TONIGHT INTO THURSDAY MORNING.
THIS COULD PROVIDE FOR A QUICK DUSTING TO INCH OF VERY LIGHT SNOW
FOR A GOOD CHUNK OF THE AREA. THE SURFACE LOW OF THE CLIPPER WILL
PASS TO OUR NORTH...AND THE ASSOCIATED COLD FRONT WILL PRETTY MUCH
WASH OUT IN OUR VICINITY THURSDAY NIGHT WITH LITTLE IMPACT EXCEPT
PERHAPS SPOTTY FLURRIES.
ON FRIDAY...WHAT IS LEFT OF THE CLIPPER FRONTAL ZONE WILL
EFFECTIVELY TURN BACK INTO A WARM FRONT AND LIFT OUT OF THE
AREA...AS SOUTHWEST FLOW DEVELOPS WELL AHEAD OF A STRONGER LOW
THAT WILL MOVE INTO THE WESTERN GREAT LAKES. THE RESULTING WARM
AIR ADVECTION WILL BOOST TEMPERATURES INTO UPPER 30S-LOWER 40S
FRIDAY...WHICH APPEARS TO BE MAINLY DRY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
STRONG DUAL LOW SYSTEM MOVES INTO THE NORTHEAST WITH A WARM
SECTOR AHEAD OF THE LOW ALLOWING FOR THE POTENTIAL OF MIXED
PRECIPITATION FRIDAY NIGHT AND SATURDAY. THE SYSTEM LIFTS TO THE
E/NE LATE SATURDAY AND ANOTHER COLD ARCTIC AIR MASS DROPS IN FROM
THE NW AND CHANGES THE PRECIP OVER TO ALL SNOW. SOME ACCUMULATION
ON THE BACK SIDE OF THE SYSTEM IS POSSIBLE.
THE INFLUX OF ANOTHER ARCTIC AIR MASS AND A W/NWLY FLOW REGIME
WILL ALLOW FOR A PERIOD OF LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT
THROUGH TUESDAY. SIGNIFICANT SNOWFALL ACCUMULATIONS ARE POSSIBLE.
COOL TEMPERATURES ARE EXPECTED THURSDAY WITH HIGHS IN THE MID TO
UPPER 20S AND LOWS IN THE TEENS AND SINGLE DIGITS. A BRIEF PERIOD
OF MILD TEMPERATURES IS ANTICIPATED FRIDAY AND SATURDAY WITH HIGHS
IN THE MID TO UPPER 30S AND LOWS IN THE 20S. A COLD AIR MASS WILL
DROP IN LATE IN THE WEEKEND AND REMAIN IN PLACE INTO EARLY NEXT
WEEK WITH HIGHS IN THE 20S AND LOWS IN THE TEENS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
INTENSE LAKE EFFECT BAND STILL AFFECTING KSYR BUT WE EXPECT
CONDITIONS TO IMPROVE BY THE MID TO LATE AFTERNOON (BY AROUND 21Z)
AS BAND MOVES NORTH. BEFORE THIS TIME BELOW ALTERNATE MIN TO EVEN
BELOW AIRPORT MIN CONDITIONS WILL CONTINUE. FOR KRME, EXPECT
CIGS/VISBYS TO GO DOWN TO IFR AROUND MID AFTERNOON AS LAKE EFFECT
BAND SHIFTS NORTH INTO THE AREA. REMAINING SITES SHOULD BE MAINLY
VFR THIS AFTERNOON THOUGH IF A BAND FROM ERIE MOVES IN KELM COULD
SEE A BRIEF PERIOD OF RESTRICTIONS.
FOR TONIGHT, LAKE EFFECT WILL HAVE MOVED OUT OF THE AREA BY AROUND 0Z.
HOWEVER EXPECT A CLIPPER SYSTEM TO MOVE IN OVERNIGHT AND BRING
LIGHT SNOW WITH GENERALLY MVFR CIGS/VISBYS. WE DID, HOWEVER, ADD
IN A TEMPO IFR GROUP FOR KITH/KBGM NEAR DAWN WHEN SNOW MAY BE JUST
A BIT HEAVIER. CLIPPER MOVES OUT FOR THURSDAY WITH MAINLY JUST
SOME UNRESTRICTIVE FLURRIES AROUND BUT MVFR CIGS LINGERING.
WINDS WILL BE W/NW 10-20 GUSTING TO 25 KTS THIS AFTERNOON
DIMINISHING TONIGHT.
.OUTLOOK...
THURS NIGHT-FRI...MAINLY MVFR DUE TO LOW CIGS.
SAT...MVFR/IFR IN RAIN/SNOW.
SUN - MON...MVFR/IFR POSSIBLE SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
NYZ009-018-036-037.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ046.
&&
$$
SYNOPSIS...ABS
NEAR TERM...MDP
SHORT TERM...MDP
LONG TERM...BJT
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1113 AM EST WED JAN 13 2016
.SYNOPSIS...
HEAVY LAKE EFFECT SNOW WILL CONTINUE TODAY IN PARTS OF CENTRAL NEW
YORK DOWNWIND OF LAKE ONTARIO...ESPECIALLY THE SYRACUSE METRO
AREA AND NORTHERN ONEIDA COUNTY. THE REST OF THE REGION WILL BE
COLD AND BRISK WITH SCATTERED SNOW SHOWERS OR FLURRIES FROM A LAKE
ERIE SNOW BAND. LIGHT SNOW IS POSSIBLE WITH ANOTHER CLIPPER SYSTEM
LATE TONIGHT INTO THURSDAY. A STRONGER SYSTEM IS EXPECTED FRIDAY
NIGHT THROUGH SATURDAY NIGHT WITH A MIX OF RAIN AND SNOW POSSIBLE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1110 AM UPDATE...
MADE SOME ADJUSTEMENT TO THE FORECAST TO ACCOUNT FOR TRENDS ON
RADAR AND WIND FLOW FOR THE LAKE EFFECT BANDS FROM BOTH ERIE AND
ONTARIO. HEAVY SNOW WILL CONTINUE AS THE RADAR SHOWED
INTENSIFICATION WITH THE ONTARIO BAND THROUGH THE NEXT FEW HOURS
WITH A SLIGHT BUT STEADY NUDGE NORTH STARTING AROUND 1PM. LAKE
ERIE BAND DROPPING LIGHT SNOW WELL INTO CNY AND EVEN FAR NE PA
BEFORE DROPPING OFF NEAR I-81. HAVE ADJUSTED CLOUD COVER AND POPS
DOWN IN AREAS IN BETWEEN THE BANDS.
410 AM UPDATE...
HEAVY LAKE EFFECT SNOW IS ONGOING IN PARTS OF CENTRAL NEW YORK. AS
IS TYPICAL...THE BAND /OR AT TIMES BANDS/ IS FLUCTUATING IN
PLACEMENT BY THE HOUR. THIS IS OCCURRING WITH EACH PASSING RIPPLE
EMBEDDED WITHIN THE FLOW ON THE BACK SIDE OF THE UPPER TROUGH THAT
IS GRADUALLY LIFTING NORTHEAST. 1 TO 2 INCH PER HOUR SNOWFALL
RATES WILL CONTINUE WITHIN THE HEAVIEST BANDS EARLY THIS
MORNING...NOW SLAMMING THE SYRACUSE METRO AREA EAST TO ABOUT
VERONA...TO SOUTH OF UTICA. LOCAL CONDITIONS WILL VARY WIDELY WITH
ABRUPT NEAR WHITE-OUT CONDITIONS POSSIBLE AT TIMES. WEST WIND WILL
ALSO STILL GUST TO 30 MPH THROUGH THE MORNING WHICH WILL TEND TO
DRIFT THE DRY AND FLUFFY SNOW. THIS WILL MAKE IT A CHALLENGE TO
KEEP ROADS CLEAR...ESPECIALLY NORTH-SOUTH ORIENTED ROUTES.
AN INTERRUPTION IN INTENSITY MAY OCCUR AROUND MID MORNING...BEFORE
THE BAND REINVIGORATES EARLY AFTERNOON WHILE SHIFTING GRADUALLY
NORTH AND CATCHING A LONGER FETCH DOWN THE LENGTH OF LAKE ONTARIO.
THUS FAR...A TOO-FAR-SOUTHWARD BIAS HAS BEEN DEPICTED BY ARW NMM
HRRR AND RUC MODELS...WHICH HAS BEEN OBSERVED TO BE COMMON WITH
LAKE ONTARIO LAKE EFFECT EVENTS IN THE PAST. I HAVE CONTINUED TO
LEAN ON THE CANADIAN AND TO A LESSER DEGREE THE NAM FOR
EXPECTATIONS OF BAND PLACEMENT. THAT BEING SAID...THERE IS SOME
SORT OF SMALL MCV/VORTICITY FEATURE THAT WAS OBSERVED CROSSING
LAKE HURON TO THE ONTARIO PENINSULA...AND NOW GETTING INTO FAR
WESTERN LAKE ONTARIO. I SUSPECT THIS IS WHAT MAY CAUSE THE LAKE
EFFECT TO LOSE A LITTLE ORGANIZATION LATER THIS MORNING...WHICH
THE LATEST 06Z NAM ALSO SEEMS TO BE LATCHING ON.
EARLY THIS AFTERNOON LAKE EFFECT SHOULD BE AGAIN PRETTY STOUT
ALONG THE NY THRUWAY AT FIRST...BUT LIFTING NORTHWARD WITH TIME.
IT SHOULD BE NORTH OF SYRACUSE BY MID AFTERNOON...NORTH OF UTICA
BY MID-TO-LATE AFTERNOON...AND THEN EXIT NORTHERN ONEIDA COUNTY
EARLY EVENING.
FOR THE REST OF THE REGION...GENERALLY JUST A COLD BRISK DAY WITH
SCATTERED SNOW SHOWERS AND FLURRIES...MAINLY TWIN TIERS NORTHWARD.
TEMPERATURES WILL PRETTY MUCH HOLD IN THE UPPER TEENS-LOWER 20S.
LAKE ERIE BANDS WILL AT TIMES EXTEND ACROSS THE CENTRAL TWIN
TIERS TO PROVIDE LIGHT DUSTINGS OF SNOW...WHICH THE WIND WILL
EASILY PICK UP AND BLOW AROUND. THERE COULD BE AN INCH OR TWO
ACCUMULATION ESPECIALLY STEUBEN-YATES- SCHUYLER. T
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
LAKE ONTARIO BAND WILL SHIFT NORTH OF THE AREA THIS EVENING...BUT
ALREADY IN THIS BUSY PATTERN...THE WARM AIR ADVECTION SIDE OF
ANOTHER CLIPPER WILL MOVE IN LATE TONIGHT INTO THURSDAY MORNING.
THIS COULD PROVIDE FOR A QUICK DUSTING TO INCH OF VERY LIGHT SNOW
FOR A GOOD CHUNK OF THE AREA. THE SURFACE LOW OF THE CLIPPER WILL
PASS TO OUR NORTH...AND THE ASSOCIATED COLD FRONT WILL PRETTY MUCH
WASH OUT IN OUR VICINITY THURSDAY NIGHT WITH LITTLE IMPACT EXCEPT
PERHAPS SPOTTY FLURRIES.
ON FRIDAY...WHAT IS LEFT OF THE CLIPPER FRONTAL ZONE WILL
EFFECTIVELY TURN BACK INTO A WARM FRONT AND LIFT OUT OF THE
AREA...AS SOUTHWEST FLOW DEVELOPS WELL AHEAD OF A STRONGER LOW
THAT WILL MOVE INTO THE WESTERN GREAT LAKES. THE RESULTING WARM
AIR ADVECTION WILL BOOST TEMPERATURES INTO UPPER 30S-LOWER 40S
FRIDAY...WHICH APPEARS TO BE MAINLY DRY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
STRONG DUAL LOW SYSTEM MOVES INTO THE NORTHEAST WITH A WARM
SECTOR AHEAD OF THE LOW ALLOWING FOR THE POTENTIAL OF MIXED
PRECIPITATION FRIDAY NIGHT AND SATURDAY. THE SYSTEM LIFTS TO THE
E/NE LATE SATURDAY AND ANOTHER COLD ARCTIC AIR MASS DROPS IN FROM
THE NW AND CHANGES THE PRECIP OVER TO ALL SNOW. SOME ACCUMULATION
ON THE BACK SIDE OF THE SYSTEM IS POSSIBLE.
THE INFLUX OF ANOTHER ARCTIC AIR MASS AND A W/NWLY FLOW REGIME
WILL ALLOW FOR A PERIOD OF LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT
THROUGH TUESDAY. SIGNIFICANT SNOWFALL ACCUMULATIONS ARE POSSIBLE.
COOL TEMPERATURES ARE EXPECTED THURSDAY WITH HIGHS IN THE MID TO
UPPER 20S AND LOWS IN THE TEENS AND SINGLE DIGITS. A BRIEF PERIOD
OF MILD TEMPERATURES IS ANTICIPATED FRIDAY AND SATURDAY WITH HIGHS
IN THE MID TO UPPER 30S AND LOWS IN THE 20S. A COLD AIR MASS WILL
DROP IN LATE IN THE WEEKEND AND REMAIN IN PLACE INTO EARLY NEXT
WEEK WITH HIGHS IN THE 20S AND LOWS IN THE TEENS.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
HEAVY LAKE EFFECT SNOW WILL AFFECT KSYR-KRME WITH HIGHLY VARIABLE...AND
RESTRICTIVE FLIGHT CONDITIONS THIS MORNING. CONDITIONS ARE EXPECTED
TO IMPROVE TO VFR-MVFR THIS AFTERNOON AS SNOW SQUALLS LIFT NORTHEAST.
ELSEWHERE...GENERALLY BKN VFR CEILINGS WITH OCCASIONAL SNOW
SHOWERS BRINGING LESS THAN AN HOUR OF IFR VSBY/MVFR CIG TO THE
CENTRAL NEW YORK AIRPORTS AT ANY TIME. DID NOT COMPLICATE THE TAFS WITH
THESE INTERMITTENT RESTRICTIONS...ALTHOUGH PILOTS SHOULD BE AWARE
THAT IMC COULD QUICKLY DEVELOP WITHIN THE LOCAL PATTERN.
GOOD TO GO WITH VFR AT KAVP.
GUSTY WEST-NORTHWEST WINDS 15-30 KTS THIS MORNING EASES TO 5-15
KTS AND BACKS SOUTHWEST TONIGHT.
.OUTLOOK...
WED NGT...MVFR-IFR. PERIODS OF LIGHT SNOW.
THURS-FRI...MAINLY VFR.
SAT...MVFR/IFR IN RAIN/SNOW.
SUN...MVFR/IFR POSSIBLE SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
NYZ009-018-036-037.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ046.
&&
$$
SYNOPSIS...ABS
NEAR TERM...MDP/ABS
SHORT TERM...MDP
LONG TERM...BJT
AVIATION...JAB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
655 AM EST WED JAN 13 2016
.SYNOPSIS...
HEAVY LAKE EFFECT SNOW WILL CONTINUE TODAY IN PARTS OF CENTRAL NEW
YORK DOWNWIND OF LAKE ONTARIO...ESPECIALLY THE SYRACUSE METRO
AREA. THE REST OF THE REGION WILL BE COLD AND BRISK WITH SCATTERED
SNOW SHOWERS OR FLURRIES. LIGHT SNOW IS POSSIBLE WITH ANOTHER CLIPPER
SYSTEM LATE TONIGHT INTO THURSDAY. A STRONGER SYSTEM IS EXPECTED FRIDAY
NIGHT THROUGH SATURDAY NIGHT WITH A MIX OF RAIN AND SNOW POSSIBLE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
410 AM UPDATE...
HEAVY LAKE EFFECT SNOW IS ONGOING IN PARTS OF CENTRAL NEW YORK. AS
IS TYPICAL...THE BAND /OR AT TIMES BANDS/ IS FLUCTUATING IN
PLACEMENT BY THE HOUR. THIS IS OCCURRING WITH EACH PASSING RIPPLE
EMBEDDED WITHIN THE FLOW ON THE BACK SIDE OF THE UPPER TROUGH THAT
IS GRADUALLY LIFTING NORTHEAST. 1 TO 2 INCH PER HOUR SNOWFALL
RATES WILL CONTINUE WITHIN THE HEAVIEST BANDS EARLY THIS
MORNING...NOW SLAMMING THE SYRACUSE METRO AREA EAST TO ABOUT
VERONA...TO SOUTH OF UTICA. LOCAL CONDITIONS WILL VARY WIDELY WITH
ABRUPT NEAR WHITE-OUT CONDITIONS POSSIBLE AT TIMES. WEST WIND WILL
ALSO STILL GUST TO 30 MPH THROUGH THE MORNING WHICH WILL TEND TO
DRIFT THE DRY AND FLUFFY SNOW. THIS WILL MAKE IT A CHALLENGE TO
KEEP ROADS CLEAR...ESPECIALLY NORTH-SOUTH ORIENTED ROUTES.
AN INTERRUPTION IN INTENSITY MAY OCCUR AROUND MID MORNING...BEFORE
THE BAND REINVIGORATES EARLY AFTERNOON WHILE SHIFTING GRADUALLY
NORTH AND CATCHING A LONGER FETCH DOWN THE LENGTH OF LAKE ONTARIO.
THUS FAR...A TOO-FAR-SOUTHWARD BIAS HAS BEEN DEPICTED BY ARW NMM
HRRR AND RUC MODELS...WHICH HAS BEEN OBSERVED TO BE COMMON WITH
LAKE ONTARIO LAKE EFFECT EVENTS IN THE PAST. I HAVE CONTINUED TO
LEAN ON THE CANADIAN AND TO A LESSER DEGREE THE NAM FOR
EXPECTATIONS OF BAND PLACEMENT. THAT BEING SAID...THERE IS SOME
SORT OF SMALL MCV/VORTICITY FEATURE THAT WAS OBSERVED CROSSING
LAKE HURON TO THE ONTARIO PENINSULA...AND NOW GETTING INTO FAR
WESTERN LAKE ONTARIO. I SUSPECT THIS IS WHAT MAY CAUSE THE LAKE
EFFECT TO LOSE A LITTLE ORGANIZATION LATER THIS MORNING...WHICH
THE LATEST 06Z NAM ALSO SEEMS TO BE LATCHING ON.
EARLY THIS AFTERNOON LAKE EFFECT SHOULD BE AGAIN PRETTY STOUT
ALONG THE NY THRUWAY AT FIRST...BUT LIFTING NORTHWARD WITH TIME.
IT SHOULD BE NORTH OF SYRACUSE BY MID AFTERNOON...NORTH OF UTICA
BY MID-TO-LATE AFTERNOON...AND THEN EXIT NORTHERN ONEIDA COUNTY
EARLY EVENING.
FOR THE REST OF THE REGION...GENERALLY JUST A COLD BRISK DAY WITH
SCATTERED SNOW SHOWERS AND FLURRIES...MAINLY TWIN TIERS NORTHWARD.
TEMPERATURES WILL PRETTY MUCH HOLD IN THE UPPER TEENS-LOWER 20S.
LAKE ERIE BANDS WILL AT TIMES EXTEND ACROSS THE CENTRAL TWIN
TIERS TO PROVIDE LIGHT DUSTINGS OF SNOW...WHICH THE WIND WILL
EASILY PICK UP AND BLOW AROUND. THERE COULD BE AN INCH OR TWO
ACCUMULATION ESPECIALLY STEUBEN-YATES- SCHUYLER. T
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
LAKE ONTARIO BAND WILL SHIFT NORTH OF THE AREA THIS EVENING...BUT
ALREADY IN THIS BUSY PATTERN...THE WARM AIR ADVECTION SIDE OF
ANOTHER CLIPPER WILL MOVE IN LATE TONIGHT INTO THURSDAY MORNING.
THIS COULD PROVIDE FOR A QUICK DUSTING TO INCH OF VERY LIGHT SNOW
FOR A GOOD CHUNK OF THE AREA. THE SURFACE LOW OF THE CLIPPER WILL
PASS TO OUR NORTH...AND THE ASSOCIATED COLD FRONT WILL PRETTY MUCH
WASH OUT IN OUR VICINITY THURSDAY NIGHT WITH LITTLE IMPACT EXCEPT
PERHAPS SPOTTY FLURRIES.
ON FRIDAY...WHAT IS LEFT OF THE CLIPPER FRONTAL ZONE WILL
EFFECTIVELY TURN BACK INTO A WARM FRONT AND LIFT OUT OF THE
AREA...AS SOUTHWEST FLOW DEVELOPS WELL AHEAD OF A STRONGER LOW
THAT WILL MOVE INTO THE WESTERN GREAT LAKES. THE RESULTING WARM
AIR ADVECTION WILL BOOST TEMPERATURES INTO UPPER 30S-LOWER 40S
FRIDAY...WHICH APPEARS TO BE MAINLY DRY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
STRONG DUAL LOW SYSTEM MOVES INTO THE NORTHEAST WITH A WARM
SECTOR AHEAD OF THE LOW ALLOWING FOR THE POTENTIAL OF MIXED
PRECIPITATION FRIDAY NIGHT AND SATURDAY. THE SYSTEM LIFTS TO THE
E/NE LATE SATURDAY AND ANOTHER COLD ARCTIC AIR MASS DROPS IN FROM
THE NW AND CHANGES THE PRECIP OVER TO ALL SNOW. SOME ACCUMULATION
ON THE BACK SIDE OF THE SYSTEM IS POSSIBLE.
THE INFLUX OF ANOTHER ARCTIC AIR MASS AND A W/NWLY FLOW REGIME
WILL ALLOW FOR A PERIOD OF LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT
THROUGH TUESDAY. SIGNIFICANT SNOWFALL ACCUMULATIONS ARE POSSIBLE.
COOL TEMPERATURES ARE EXPECTED THURSDAY WITH HIGHS IN THE MID TO
UPPER 20S AND LOWS IN THE TEENS AND SINGLE DIGITS. A BRIEF PERIOD
OF MILD TEMPERATURES IS ANTICIPATED FRIDAY AND SATURDAY WITH HIGHS
IN THE MID TO UPPER 30S AND LOWS IN THE 20S. A COLD AIR MASS WILL
DROP IN LATE IN THE WEEKEND AND REMAIN IN PLACE INTO EARLY NEXT
WEEK WITH HIGHS IN THE 20S AND LOWS IN THE TEENS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
HEAVY LAKE EFFECT SNOW WILL AFFECT KSYR-KRME WITH HIGHLY VARIABLE...AND
RESTRICTIVE FLIGHT CONDITIONS THIS MORNING. CONDITIONS ARE EXPECTED
TO IMPROVE TO VFR-MVFR THIS AFTERNOON AS SNOW SQUALLS LIFT NORTHEAST.
ELSEWHERE...GENERALLY BKN VFR CEILINGS WITH OCCASIONAL SNOW
SHOWERS BRINGING LESS THAN AN HOUR OF IFR VSBY/MVFR CIG TO THE
CENTRAL NEW YORK AIRPORTS AT ANY TIME. DID NOT COMPLICATE THE TAFS WITH
THESE INTERMITTENT RESTRICTIONS...ALTHOUGH PILOTS SHOULD BE AWARE
THAT IMC COULD QUICKLY DEVELOP WITHIN THE LOCAL PATTERN.
GOOD TO GO WITH VFR AT KAVP.
GUSTY WEST-NORTHWEST WINDS 15-30 KTS THIS MORNING EASES TO 5-15
KTS AND BACKS SOUTHWEST TONIGHT.
.OUTLOOK...
WED NGT...MVFR-IFR. PERIODS OF LIGHT SNOW.
THURS-FRI...MAINLY VFR.
SAT...MVFR/IFR IN RAIN/SNOW.
SUN...MVFR/IFR POSSIBLE SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
NYZ009-018-036-037.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ046.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...MDP
LONG TERM...BJT
AVIATION...JAB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
444 AM EST WED JAN 13 2016
.SYNOPSIS...
HEAVY LAKE EFFECT SNOW WILL CONTINUE TODAY IN PARTS OF CENTRAL NEW
YORK DOWNWIND OF LAKE ONTARIO...ESPECIALLY THE SYRACUSE METRO
AREA. THE REST OF THE REGION WILL BE COLD AND BRISK WITH SCATTERED
SNOW SHOWERS OR FLURRIES. LIGHT SNOW IS POSSIBLE WITH ANOTHER CLIPPER
SYSTEM LATE TONIGHT INTO THURSDAY. A STRONGER SYSTEM IS EXPECTED FRIDAY
NIGHT THROUGH SATURDAY NIGHT WITH A MIX OF RAIN AND SNOW POSSIBLE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
410 AM UPDATE...
HEAVY LAKE EFFECT SNOW IS ONGOING IN PARTS OF CENTRAL NEW YORK. AS
IS TYPICAL...THE BAND /OR AT TIMES BANDS/ IS FLUCTUATING IN
PLACEMENT BY THE HOUR. THIS IS OCCURRING WITH EACH PASSING RIPPLE
EMBEDDED WITHIN THE FLOW ON THE BACK SIDE OF THE UPPER TROUGH THAT
IS GRADUALLY LIFTING NORTHEAST. 1 TO 2 INCH PER HOUR SNOWFALL
RATES WILL CONTINUE WITHIN THE HEAVIEST BANDS EARLY THIS
MORNING...NOW SLAMMING THE SYRACUSE METRO AREA EAST TO ABOUT
VERONA...TO SOUTH OF UTICA. LOCAL CONDITIONS WILL VARY WIDELY WITH
ABRUPT NEAR WHITE-OUT CONDITIONS POSSIBLE AT TIMES. WEST WIND WILL
ALSO STILL GUST TO 30 MPH THROUGH THE MORNING WHICH WILL TEND TO
DRIFT THE DRY AND FLUFFY SNOW. THIS WILL MAKE IT A CHALLENGE TO
KEEP ROADS CLEAR...ESPECIALLY NORTH-SOUTH ORIENTED ROUTES.
AN INTERRUPTION IN INTENSITY MAY OCCUR AROUND MID MORNING...BEFORE
THE BAND REINVIGORATES EARLY AFTERNOON WHILE SHIFTING GRADUALLY
NORTH AND CATCHING A LONGER FETCH DOWN THE LENGTH OF LAKE ONTARIO.
THUS FAR...A TOO-FAR-SOUTHWARD BIAS HAS BEEN DEPICTED BY ARW NMM
HRRR AND RUC MODELS...WHICH HAS BEEN OBSERVED TO BE COMMON WITH
LAKE ONTARIO LAKE EFFECT EVENTS IN THE PAST. I HAVE CONTINUED TO
LEAN ON THE CANADIAN AND TO A LESSER DEGREE THE NAM FOR
EXPECTATIONS OF BAND PLACEMENT. THAT BEING SAID...THERE IS SOME
SORT OF SMALL MCV/VORTICITY FEATURE THAT WAS OBSERVED CROSSING
LAKE HURON TO THE ONTARIO PENINSULA...AND NOW GETTING INTO FAR
WESTERN LAKE ONTARIO. I SUSPECT THIS IS WHAT MAY CAUSE THE LAKE
EFFECT TO LOSE A LITTLE ORGANIZATION LATER THIS MORNING...WHICH
THE LATEST 06Z NAM ALSO SEEMS TO BE LATCHING ON.
EARLY THIS AFTERNOON LAKE EFFECT SHOULD BE AGAIN PRETTY STOUT
ALONG THE NY THRUWAY AT FIRST...BUT LIFTING NORTHWARD WITH TIME.
IT SHOULD BE NORTH OF SYRACUSE BY MID AFTERNOON...NORTH OF UTICA
BY MID-TO-LATE AFTERNOON...AND THEN EXIT NORTHERN ONEIDA COUNTY
EARLY EVENING.
FOR THE REST OF THE REGION...GENERALLY JUST A COLD BRISK DAY WITH
SCATTERED SNOW SHOWERS AND FLURRIES...MAINLY TWIN TIERS NORTHWARD.
TEMPERATURES WILL PRETTY MUCH HOLD IN THE UPPER TEENS-LOWER 20S.
LAKE ERIE BANDS WILL AT TIMES EXTEND ACROSS THE CENTRAL TWIN
TIERS TO PROVIDE LIGHT DUSTINGS OF SNOW...WHICH THE WIND WILL
EASILY PICK UP AND BLOW AROUND. THERE COULD BE AN INCH OR TWO
ACCUMULATION ESPECIALLY STEUBEN-YATES- SCHUYLER. T
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
LAKE ONTARIO BAND WILL SHIFT NORTH OF THE AREA THIS EVENING...BUT
ALREADY IN THIS BUSY PATTERN...THE WARM AIR ADVECTION SIDE OF
ANOTHER CLIPPER WILL MOVE IN LATE TONIGHT INTO THURSDAY MORNING.
THIS COULD PROVIDE FOR A QUICK DUSTING TO INCH OF VERY LIGHT SNOW
FOR A GOOD CHUNK OF THE AREA. THE SURFACE LOW OF THE CLIPPER WILL
PASS TO OUR NORTH...AND THE ASSOCIATED COLD FRONT WILL PRETTY MUCH
WASH OUT IN OUR VICINITY THURSDAY NIGHT WITH LITTLE IMPACT EXCEPT
PERHAPS SPOTTY FLURRIES.
ON FRIDAY...WHAT IS LEFT OF THE CLIPPER FRONTAL ZONE WILL
EFFECTIVELY TURN BACK INTO A WARM FRONT AND LIFT OUT OF THE
AREA...AS SOUTHWEST FLOW DEVELOPS WELL AHEAD OF A STRONGER LOW
THAT WILL MOVE INTO THE WESTERN GREAT LAKES. THE RESULTING WARM
AIR ADVECTION WILL BOOST TEMPERATURES INTO UPPER 30S-LOWER 40S
FRIDAY...WHICH APPEARS TO BE MAINLY DRY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
STRONG DUAL LOW SYSTEM MOVES INTO THE NORTHEAST WITH A WARM
SECTOR AHEAD OF THE LOW ALLOWING FOR THE POTENTIAL OF MIXED
PRECIPITATION FRIDAY NIGHT AND SATURDAY. THE SYSTEM LIFTS TO THE
E/NE LATE SATURDAY AND ANOTHER COLD ARCTIC AIR MASS DROPS IN FROM
THE NW AND CHANGES THE PRECIP OVER TO ALL SNOW. SOME ACCUMULATION
ON THE BACK SIDE OF THE SYSTEM IS POSSIBLE.
THE INFLUX OF ANOTHER ARCTIC AIR MASS AND A W/NWLY FLOW REGIME
WILL ALLOW FOR A PERIOD OF LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT
THROUGH TUESDAY. SIGNIFICANT SNOWFALL ACCUMULATIONS ARE POSSIBLE.
COOL TEMPERATURES ARE EXPECTED THURSDAY WITH HIGHS IN THE MID TO
UPPER 20S AND LOWS IN THE TEENS AND SINGLE DIGITS. A BRIEF PERIOD
OF MILD TEMPERATURES IS ANTICIPATED FRIDAY AND SATURDAY WITH HIGHS
IN THE MID TO UPPER 30S AND LOWS IN THE 20S. A COLD AIR MASS WILL
DROP IN LATE IN THE WEEKEND AND REMAIN IN PLACE INTO EARLY NEXT
WEEK WITH HIGHS IN THE 20S AND LOWS IN THE TEENS.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
LAKE EFFECT SNOW BANDS AFFECT KSYR WITH ALTERNATE MINIMUM...AND
OCCASIONAL AIRPORT MINIMUM RESTRICTIONS TODAY THROUGH APPROXIMATELY
21Z. CONDITIONS THEN IMPROVE TO VFR. LAKE SNOW BANDS WILL
OSCILLATE IN AND OUT OF KRME TODAY WITH CONDITIONS VARYING FROM
MVFR TO AT LEAST ALTERNATE MIN RESTRICTIONS...IF NOT WORSE. TIMING
OF BANDS MOVING THROUGH THIS TERMINAL IS A LOW CONFIDENCE
FORECAST. USE TAF PERIODS BEYOND 6 HOURS FROM CURRENT TIME WITH
CAUTION.
ELSEWHERE...VFR-MVFR CIGS AND OCCASIONAL IFR SNOW SHOWERS AT KITH-
KELM-KBGM...ENDING AFTER 18Z-21Z. VFR FOR THE ENTIRE FORECAST PERIOD
AT KAVP...ALTHOUGH A VERY BRIEF MVFR SNOW SHOWER MAY SWEEP THROUGH
THE TERMINAL VICINITY THIS MORNING.
GUSTY WEST-NORTHWEST WINDS 15G35KT THIS MORNING DIMINISH TO 10-15
KTS THIS AFTERNOON...THEN SW 5-10 KTS TONIGHT.
.OUTLOOK...
THURS-FRI...MAINLY VFR.
SAT...MVFR/IFR IN RAIN/SNOW.
SUN...MVFR/IFR POSSIBLE SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
NYZ009-018-036-037.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ046.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...MDP
LONG TERM...BJT
AVIATION...JAB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
412 AM EST WED JAN 13 2016
.SYNOPSIS...
HEAVY LAKE EFFECT SNOW WILL CONTINUE TODAY IN PARTS OF CENTRAL NEW
YORK DOWNWIND OF LAKE ONTARIO...ESPECIALLY THE SYRACUSE METRO
AREA. THE REST OF THE REGION WILL BE COLD AND BRISK WITH SCATTERED
SNOW SHOWERS OR FLURRIES. LIGHT SNOW IS POSSIBLE WITH ANOTHER CLIPPER
SYSTEM LATE TONIGHT INTO THURSDAY. A STRONGER SYSTEM IS EXPECTED FRIDAY
NIGHT THROUGH SATURDAY NIGHT WITH A MIX OF RAIN AND SNOW POSSIBLE.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
410 AM UPDATE...
HEAVY LAKE EFFECT SNOW IS ONGOING IN PARTS OF CENTRAL NEW YORK. AS
IS TYPICAL...THE BAND /OR AT TIMES BANDS/ IS FLUCTUATING IN
PLACEMENT BY THE HOUR. THIS IS OCCURRING WITH EACH PASSING RIPPLE
EMBEDDED WITHIN THE FLOW ON THE BACK SIDE OF THE UPPER TROUGH THAT
IS GRADUALLY LIFTING NORTHEAST. 1 TO 2 INCH PER HOUR SNOWFALL
RATES WILL CONTINUE WITHIN THE HEAVIEST BANDS EARLY THIS
MORNING...NOW SLAMMING THE SYRACUSE METRO AREA EAST TO ABOUT
VERONA...TO SOUTH OF UTICA. LOCAL CONDITIONS WILL VARY WIDELY WITH
ABRUPT NEAR WHITE-OUT CONDITIONS POSSIBLE AT TIMES. WEST WIND WILL
ALSO STILL GUST TO 30 MPH THROUGH THE MORNING WHICH WILL TEND TO
DRIFT THE DRY AND FLUFFY SNOW. THIS WILL MAKE IT A CHALLENGE TO
KEEP ROADS CLEAR...ESPECIALLY NORTH-SOUTH ORIENTED ROUTES.
AN INTERRUPTION IN INTENSITY MAY OCCUR AROUND MID MORNING...BEFORE
THE BAND REINVIGORATES EARLY AFTERNOON WHILE SHIFTING GRADUALLY
NORTH AND CATCHING A LONGER FETCH DOWN THE LENGTH OF LAKE ONTARIO.
THUS FAR...A TOO-FAR-SOUTHWARD BIAS HAS BEEN DEPICTED BY ARW NMM
HRRR AND RUC MODELS...WHICH HAS BEEN OBSERVED TO BE COMMON WITH
LAKE ONTARIO LAKE EFFECT EVENTS IN THE PAST. I HAVE CONTINUED TO
LEAN ON THE CANADIAN AND TO A LESSER DEGREE THE NAM FOR
EXPECTATIONS OF BAND PLACEMENT. THAT BEING SAID...THERE IS SOME
SORT OF SMALL MCV/VORTICITY FEATURE THAT WAS OBSERVED CROSSING
LAKE HURON TO THE ONTARIO PENINSULA...AND NOW GETTING INTO FAR
WESTERN LAKE ONTARIO. I SUSPECT THIS IS WHAT MAY CAUSE THE LAKE
EFFECT TO LOSE A LITTLE ORGANIZATION LATER THIS MORNING...WHICH
THE LATEST 06Z NAM ALSO SEEMS TO BE LATCHING ON.
EARLY THIS AFTERNOON LAKE EFFECT SHOULD BE AGAIN PRETTY STOUT
ALONG THE NY THRUWAY AT FIRST...BUT LIFTING NORTHWARD WITH TIME.
IT SHOULD BE NORTH OF SYRACUSE BY MID AFTERNOON...NORTH OF UTICA
BY MID-TO-LATE AFTERNOON...AND THEN EXIT NORTHERN ONEIDA COUNTY
EARLY EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
THE LAKE EFFECT SNOW BANDS WILL SHIFT BACK TO THE NORTH LATE WED
AFTERNOON AND INTO THE EVENING AS THE WINDS BACK TO THE SW. WILL
ALSO SEE THE ARCTIC AIR GET SHUNTED TO THE NORTH AS WEAK RIDGING
OCCURS AHEAD OF A WEAK S/W EXPECTED LATER IN THE WORK WEEK.
LINGERING LIGHT SNOW OVER THE SOUTHERN TUG HILL PLATEAU WILL
CONTINUE INTO WED NIGHT...BUT ADDITIONAL AMOUNTS WILL BE LIGHT.
A WEAK S/W WILL MOVE ACROSS THE EASTERN GREAT LAKES ON THURSDAY
BUT MAINLY ACT TO INCREASE CLOUD COVER AND PRODUCE WIDESPREAD
LIGHT SNOW ACROSS THE FORECAST AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
WAVE WASHES OUT LATE THURSDAY AS A MUCH BROADER AREA OF HIGH
PRESSURE BUILDS IN OVER THE NORTHEAST AHEAD OF A STRONG DUAL LOW
SYSTEM MOVES INTO THE NORTHEAST WITH A WARM SECTOR AHEAD OF THE
LOW ALLOWING FOR THE POTENTIAL OF MIXED PRECIPITATION FRIDAY NIGHT
AND SATURDAY. THE SYSTEM LIFTS TO THE E/NE LATE SATURDAY AND
ANOTHER COLD ARCTIC AIR MASS DROPS IN FROM THE NW AND CHANGES THE
PRECIP OVER TO ALL SNOW. SOME ACCUMULATION ON THE BACK SIDE OF THE
SYSTEM IS POSSIBLE.
THE INFLUX OF ANOTHER ARCTIC AIR MASS AND A W/NWLY FLOW REGIME
WILL ALLOW FOR A PERIOD OF LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT
THROUGH TUESDAY. SIGNIFICANT SNOWFALL ACCUMULATIONS ARE POSSIBLE.
COOL TEMPERATURES ARE EXPECTED THURSDAY WITH HIGHS IN THE MID TO
UPPER 20S AND LOWS IN THE TEENS AND SINGLE DIGITS. A BRIEF PERIOD
OF MILD TEMPERATURES IS ANTICIPATED FRIDAY AND SATURDAY WITH HIGHS
IN THE MID TO UPPER 30S AND LOWS IN THE 20S. A COLD AIR MASS WILL
DROP IN LATE IN THE WEEKEND AND REMAIN IN PLACE INTO EARLY NEXT
WEEK WITH HIGHS IN THE 20S AND LOWS IN THE TEENS.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
LAKE EFFECT SNOW BANDS AFFECT KSYR WITH ALTERNATE MINIMUM...AND
OCCASIONAL AIRPORT MINIMUM RESTRICTIONS TODAY THROUGH APPROXIMATELY
21Z. CONDITIONS THEN IMPROVE TO VFR. LAKE SNOW BANDS WILL
OSCILLATE IN AND OUT OF KRME TODAY WITH CONDITIONS VARYING FROM
MVFR TO AT LEAST ALTERNATE MIN RESTRICTIONS...IF NOT WORSE. TIMING
OF BANDS MOVING THROUGH THIS TERMINAL IS A LOW CONFIDENCE
FORECAST. USE TAF PERIODS BEYOND 6 HOURS FROM CURRENT TIME WITH
CAUTION.
ELSEWHERE...VFR-MVFR CIGS AND OCCASIONAL IFR SNOW SHOWERS AT KITH-
KELM-KBGM...ENDING AFTER 18Z-21Z. VFR FOR THE ENTIRE FORECAST PERIOD
AT KAVP...ALTHOUGH A VERY BRIEF MVFR SNOW SHOWER MAY SWEEP THROUGH
THE TERMINAL VICINITY THIS MORNING.
GUSTY WEST-NORTHWEST WINDS 15G35KT THIS MORNING DIMINISH TO 10-15
KTS THIS AFTERNOON...THEN SW 5-10 KTS TONIGHT.
.OUTLOOK...
THURS-FRI...MAINLY VFR.
SAT...MVFR/IFR IN RAIN/SNOW.
SUN...MVFR/IFR POSSIBLE SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR
NYZ009-018-036-037.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ046.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...JAB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
926 PM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 926 PM CST THU JAN 14 2016
VIS HAS COME UP TO 4SM AT PKD AND OVER 2SM AT DTL...AND THERE
SEEMS TO BE A WEAKENING TREND...SO WENT AHEAD AND LET THE HEADLINE
EXPIRE AT 03Z. THE WINDS HAVE BEEN PICKING UP A BIT FROM THE NORTH
BEHIND THE BAND...WITH SOME DRIFTING SNOW AND EVEN VIS REDUCTIONS
TO 1SM AT KFAR. THINK IT WILL BE SHORT LIVED SO JUST INSERTED A
MENTION IN THE EXPIRATION STATEMENT BUT WILL MONITOR IN CASE THE
WINDS LAST A BIT LONGER THAN EXPECTED. SFC HIGH PRESSURE HAS BEEN
BUILDING INTO THE NORTHERN CWA AND THERE HAS BEEN QUITE A BIT OF
CLEARING ACROSS THE NORTH. ADJUSTED CLOUD COVER FOR THIS CLEARING
AREA MOVING SOUTH THROUGHOUT THE NIGHT. THINK THAT CLOUDS WILL
MOVE BACK INTO THE NORTH LATE BUT NOT BEFORE TEMPS BOTTOM OUT NEAR
-10 IN THAT AREA. CURRENT READINGS HAVE A GOOD START.
UPDATE ISSUED AT 709 PM CST THU JAN 14 2016
ADJUSTED THE HEADLINE A BIT...AS SNOW CONTINUES OVER THE
SOUTHEASTERN COUNTIES IN THE ADVISORY. RADAR RETURNS ARE GOING
DOWN BUT PARTLY BECAUSE OF THE BEAM HEIGHT ISSUES. VIS AT DETROIT
LAKES HAS BEEN AROUND 1 TO 1 1/2 MILES FOR THE LAST FEW
HOURS...AND THE RAP HAS THE FRONTOGENESIS HANGING AROUND THROUGH
EARLY EVENING OVER WEST CENTRAL MINNESOTA. WILL EXTEND PART OF THE
ADVISORY UNTIL 03Z...BUT LET CASS...NORMAN...EASTERN POLK AND
NORTHERN CLEARWATER GO AS THE SNOW HAS ALREADY OR NEARLY CLEARED
THOSE AREAS.
UPDATE ISSUED AT 608 PM CST THU JAN 14 2016
PUT OUT A QUICK UPDATE TO TRIM THE WESTERN AND NORTHERN ENDS OF
THE ADVISORY OUT. THE WHOLE THING EXPIRES AT 7...AND WILL MONITOR
OVER THE NEXT HOUR AND DECIDE IF WE NEED TO EXTEND ANY PART OF THE
REMAINING COUNTIES OR IF THE BAND WILL DIMINISH ENOUGH TO LET IT
GO COMPLETELY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 318 PM CST THU JAN 14 2016
AS THE CURRENT SNOW EVENT WINDS DOWN...THE FOCUS WILL SHIFT BACK
TO THE COLD AND WIND CHILLS AGAIN. AS OF NOW...SEEING THE LIGHT
SNOW ENDING ACROSS THE DEVILS LAKE REGION. THE SNOW SHOULD BE
DECREASING ACROSS THE GRAND FORKS TO JAMESTOWN CORRIDOR IN THE
NEXT HOUR OR SO. THE SNOW WILL TAKE THE LONGEST TO CLEAR FROM
WEST CENTRAL MN. RADAR SHOWS THAT AREAS ALONG THE ND/SD BORDER
INTO WEST CENTRAL MN WILL BEGIN TO RECEIVE A LITTLE SNOW TOO OVER
THE NEXT FEW HOURS. NO SHIFT TO THE MAIN CORRIDOR OF 3 TO 5
INCHES...FROM NEW ROCKFORD TO HILLSBORO TO PARK RAPIDS...WHICH
WILL END FROM WEST TO EAST OVER THE NEXT FEW HOURS. CURRENT
ADVISORY ENDS AT 7 PM...BUT SHOULD BE ABLE TO TRIM SOME COUNTIES
FROM WEST TO EAST PRIOR TO THAT TIME. AFTER ADVISORY ENDS WILL BE
DEALING MORE WITH TEMPS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 318 PM CST THU JAN 14 2016
STILL LOOKING QUITE FRIGID THIS WEEKEND AND WILL BE DEALING WITH
WIND CHILL PRODUCTS FOR MOST OF IT.
A FRIGID ARCTIC AIRMASS WILL BE IN PLACE EARLY IN THE LONG
TERM...WITH TEMPERATURES BEING SUB ZERO THROUGH TUESDAY WHEN
DAYTIME HIGHS WILL BE IN LOW SINGLE DIGITS ABOVE ZERO. THIS SUPER
DRY AIRMASS WILL BE HARD TO OVERCOME...HOWEVER MODELS DO INDICATE
AN UPPER WAVE IN THE NW FLOW ALOFT MOVING ACROSS THE REGION IN THE
TUESDAY TIMEFRAME. THIS COULD PROVIDE A LIGHT DUSTING OF SNOW BUT
NOT SUFFICIENT MOISTURE FOR ANYTHING SIGNIFICANT. THE REMAINDER OF
THE WORK WEEK WILL BE DRY WITH MUCH MILDER (WARMER) TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 608 PM CST THU JAN 14 2016
THE SNOW BAND CONTINUES OVER KFAR AND KBJI...BUT HAS CLEARED OUT
OF THE NORTHERN TAF SITES. SOME VIS VARIATION BETWEEN 1 AND 2SM
FOR THE NEXT FEW HOURS AT KFAR AND KBJI...WITH BRIEF FORAYS DOWN
BELOW 1SM. AFTER 02Z WE SHOULD SEE VIS AROUND 3-5SM BEFORE ENDING
COMPLETELY LATER THIS EVENING. SOME CLEARING HAS ENTERED THE
NORTHERN FORECAST AREA AND OTHER THAN SOME SPOTTY VFR CIGS OF
4000-12000 FT...EXTENDS UP INTO SOUTHERN CANADA. THINK WE WILL
HAVE A PERIOD OF VFR CONDITIONS FOR A WHILE TONIGHT...ALTHOUGH
STRATUS COULD HANG AROUND LONGER AT KBJI. SAT LOOP SHOWS OVER
NORTHERN MANITOBA AND SASKATCHEWAN A FAIRLY EXTENSIVE STRATUS
LAYER WITH THE COLDER AIR DUE TO COME IN TOMORROW. SO HAVE
CONDITIONS RETURNING BACK TO MVFR. WINDS WILL BE FROM THE NORTH IN
MOST AREAS WITH SOME BREEZINESS THIS EVENING BUT SHOULD BE BACK
BELOW 12 KTS LATER TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...GODON/SPEICHER
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
709 PM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 709 PM CST THU JAN 14 2016
ADJUSTED THE HEADLINE A BIT...AS SNOW CONTINUES OVER THE
SOUTHEASTERN COUNTIES IN THE ADVISORY. RADAR RETURNS ARE GOING
DOWN BUT PARTLY BECAUSE OF THE BEAM HEIGHT ISSUES. VIS AT DETROIT
LAKES HAS BEEN AROUND 1 TO 1 1/2 MILES FOR THE LAST FEW
HOURS...AND THE RAP HAS THE FRONTOGENESIS HANGING AROUND THROUGH
EARLY EVENING OVER WEST CENTRAL MINNESOTA. WILL EXTEND PART OF THE
ADVISORY UNTIL 03Z...BUT LET CASS...NORMAN...EASTERN POLK AND
NORTHERN CLEARWATER GO AS THE SNOW HAS ALREADY OR NEARLY CLEARED
THOSE AREAS.
UPDATE ISSUED AT 608 PM CST THU JAN 14 2016
PUT OUT A QUICK UPDATE TO TRIM THE WESTERN AND NORTHERN ENDS OF
THE ADVISORY OUT. THE WHOLE THING EXPIRES AT 7...AND WILL MONITOR
OVER THE NEXT HOUR AND DECIDE IF WE NEED TO EXTEND ANY PART OF THE
REMAINING COUNTIES OR IF THE BAND WILL DIMINISH ENOUGH TO LET IT
GO COMPLETELY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 318 PM CST THU JAN 14 2016
AS THE CURRENT SNOW EVENT WINDS DOWN...THE FOCUS WILL SHIFT BACK
TO THE COLD AND WIND CHILLS AGAIN. AS OF NOW...SEEING THE LIGHT
SNOW ENDING ACROSS THE DEVILS LAKE REGION. THE SNOW SHOULD BE
DECREASING ACROSS THE GRAND FORKS TO JAMESTOWN CORRIDOR IN THE
NEXT HOUR OR SO. THE SNOW WILL TAKE THE LONGEST TO CLEAR FROM
WEST CENTRAL MN. RADAR SHOWS THAT AREAS ALONG THE ND/SD BORDER
INTO WEST CENTRAL MN WILL BEGIN TO RECEIVE A LITTLE SNOW TOO OVER
THE NEXT FEW HOURS. NO SHIFT TO THE MAIN CORRIDOR OF 3 TO 5
INCHES...FROM NEW ROCKFORD TO HILLSBORO TO PARK RAPIDS...WHICH
WILL END FROM WEST TO EAST OVER THE NEXT FEW HOURS. CURRENT
ADVISORY ENDS AT 7 PM...BUT SHOULD BE ABLE TO TRIM SOME COUNTIES
FROM WEST TO EAST PRIOR TO THAT TIME. AFTER ADVISORY ENDS WILL BE
DEALING MORE WITH TEMPS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 318 PM CST THU JAN 14 2016
STILL LOOKING QUITE FRIGID THIS WEEKEND AND WILL BE DEALING WITH
WIND CHILL PRODUCTS FOR MOST OF IT.
A FRIGID ARCTIC AIRMASS WILL BE IN PLACE EARLY IN THE LONG
TERM...WITH TEMPERATURES BEING SUB ZERO THROUGH TUESDAY WHEN
DAYTIME HIGHS WILL BE IN LOW SINGLE DIGITS ABOVE ZERO. THIS SUPER
DRY AIRMASS WILL BE HARD TO OVERCOME...HOWEVER MODELS DO INDICATE
AN UPPER WAVE IN THE NW FLOW ALOFT MOVING ACROSS THE REGION IN THE
TUESDAY TIMEFRAME. THIS COULD PROVIDE A LIGHT DUSTING OF SNOW BUT
NOT SUFFICIENT MOISTURE FOR ANYTHING SIGNIFICANT. THE REMAINDER OF
THE WORK WEEK WILL BE DRY WITH MUCH MILDER (WARMER) TEMPERATURES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 608 PM CST THU JAN 14 2016
THE SNOW BAND CONTINUES OVER KFAR AND KBJI...BUT HAS CLEARED OUT
OF THE NORTHERN TAF SITES. SOME VIS VARIATION BETWEEN 1 AND 2SM
FOR THE NEXT FEW HOURS AT KFAR AND KBJI...WITH BRIEF FORAYS DOWN
BELOW 1SM. AFTER 02Z WE SHOULD SEE VIS AROUND 3-5SM BEFORE ENDING
COMPLETELY LATER THIS EVENING. SOME CLEARING HAS ENTERED THE
NORTHERN FORECAST AREA AND OTHER THAN SOME SPOTTY VFR CIGS OF
4000-12000 FT...EXTENDS UP INTO SOUTHERN CANADA. THINK WE WILL
HAVE A PERIOD OF VFR CONDITIONS FOR A WHILE TONIGHT...ALTHOUGH
STRATUS COULD HANG AROUND LONGER AT KBJI. SAT LOOP SHOWS OVER
NORTHERN MANITOBA AND SASKATCHEWAN A FAIRLY EXTENSIVE STRATUS
LAYER WITH THE COLDER AIR DUE TO COME IN TOMORROW. SO HAVE
CONDITIONS RETURNING BACK TO MVFR. WINDS WILL BE FROM THE NORTH IN
MOST AREAS WITH SOME BREEZINESS THIS EVENING BUT SHOULD BE BACK
BELOW 12 KTS LATER TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ003-
017-022>024-027-028.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...GODON/SPEICHER
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1254 PM CST WED JAN 13 2016
.UPDATE...
ISSUED AT 1254 PM CST WED JAN 13 2016
WE INCREASED HIGH TEMPERATURES OVER SOUTHWEST AND SOUTH CENTRAL ND
WITH THIS UPDATE AS THE EASTWARD ADVANCE OF A SURFACE WARM FRONT
HAS ALLOWED EVEN BISMARCK TO RISE INTO THE LOWER 30S F AS OF 1845
UTC. DEEPER INTO THE COOLER AIR MASS FURTHER EAST...FOG IS BEING
REPORTED BY THE ROLLA AND RUGBY AWOS SITES...SO WE ADDED A MENTION
OF PATCHY FOG TO THOSE AREAS THROUGH THIS EVENING.
UPDATE ISSUED AT 953 AM CST WED JAN 13 2016
NO REAL CHANGE WITH THIS UPDATE...THOUGH WE DID UTILIZE A TIME-
LAGGED ENSEMBLE OF SHORT-RANGE MODEL GUIDANCE TO SLIGHTLY ALTER
HOURLY POPS LATE THIS AFTERNOON INTO THE EVENING. A TIME-LAGGED
ENSEMBLE OF THE LAST 3 RAP RUNS ACTUALLY SUGGESTS THE MELTING
LAYER ALOFT MAY NOT BE QUITE WARM ENOUGH FOR LIGHT FREEZING RAIN
POTENTIAL IN NORTHWEST ND LIKE WE HAVE ADVERTISED...BUT WE WILL
CERTAINLY KEEP IT IN THE FORECAST AS PRECIPITATION-TYPE ALGORITHM
OUTPUT FROM THE RAP AND OTHER GUIDANCE STILL SUPPORTS THE CHANCE.
UPDATE ISSUED AT 621 AM CST WED JAN 13 2016
NO SIGNIFICANT UPDATES THIS MORNING OTHER THAN TEMPERATURES. A
PATCH OF CLEAR SKIES ACROSS CENTRAL NORTH DAKOTA HAS ALLOWED
TEMPERATURES TO FALL INTO THE SINGLE DIGITS WHILE CLOUDS
ASSOCIATED WITH A QUICK MOVING SHORTWAVE IN EASTERN PORTION OF
CENTRAL NORTH DAKOTA HAVE CAUSED TEMPERATURES TO RISE THERE FROM
EARLIER LOWS IN THE SINGLE DIGITS. FARTHER WEST...MORE MILD AIR
HAS MOVED INTO THE FAR WEST WITH TEMPERATURES GENERALLY IN THE
TEENS NORTHWEST TO 20S SOUTHWEST. LIGHT SNOW HAS ENDED OVER
EASTERN PORTIONS OF CENTRAL NORTH DAKOTA. WILL UPDATE CURRENT LOW
TEMPERATURES AND BLEND THROUGH MID MORNING. UPDATED TEXT PRODUCTS
WILL BE SENT SHORTLY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 242 AM CST WED JAN 13 2016
MAIN CONCERNS IN THE SHORT TERM IS PRECIPITATION TYPE...WHICH
COMES IN TWO DISTINCT AREAS...ONE AREA IN NORTHWEST THROUGH NORTH
CENTRAL/TURTLE MOUNTAINS LATER THIS AFTERNOON THROUGH TONIGHT...AND
THE SECOND AREA DEVELOPING AFTER MIDNIGHT INTO MID MORNING THURSDAY
ACROSS SOUTHWEST AND INTO SOUTH CENTRAL NORTH DAKOTA.
MODEL CONSENSUS ON TIMING AND COVERAGE OF PRECIPITATION STILL
SUSPECT...HOWEVER THE IDEA OF TWO PRECIPITATION AREAS WITH THE
POTENTIAL FOR BOTH LIGHT FREEZING RAIN AND SNOW IS WELL AGREED
UPON PER NAM/GFS/SREF BUFKIT SOUNDINGS. HENCE USED A BLEND OF
THESE SOUNDINGS FOR THE AREAS MENTIONED ABOVE TO ADJUST THE
GIVEN SUPERBLEND WEATHER GRIDS.
CURRENT SUITE OF SATELLITE IMAGERY SHOWS A BREAK IN THE OVERCAST
CONDITIONS FOR WESTERN AND MOST OF CENTRAL NORTH DAKOTA EARLY THIS
MORNING. THE EXCEPTION IS THE TURTLE MOUNTAINS AND INTO THE JAMES
RIVER VALLEY WHERE A FAST MOVING SHORTWAVE EXTENDING FROM SOUTHWEST
MANITOBA WAS GENERATING CLOUDS AND PERIODIC WAVES OF LIGHT SNOW
MOSTLY FROM ROLETTE COUNTY EASTWARD. THIS ACTIVITY WILL WANE
AFTER 12Z WEDS AS THE SHORTWAVE SHIFTS FARTHER EAST. HIGH CLOUDS
QUICKLY INCREASING ACROSS CENTRAL/EASTERN MONTANA INDICATIVE OF
THE NEXT SURGE OF WARM AIR ADVECTION. SHOULD SEE SOME SUNSHINE
EARLY TODAY THEN CLOUDING UP FROM NORTHWEST TO SOUTHEAST. A
BAROCLINIC ZONE WAS SITUATED FROM NORTHWEST INTO NORTH CENTRAL
NORTH DAKOTA/TURTLE MOUNTAINS...AND SOUTHEAST INTO THE NORTHERN
JAMES RIVER VALLEY THIS MORNING. EXPECT A DISTINCT HIGH TEMPERATURE
FORECAST TODAY WITH HIGHS IN THE LOWER 40S FAR SOUTHWEST TO MID-
TEENS IN THE TURTLE MOUNTAINS AS THE BAROCLINIC ZONE TIGHTENS UP
THIS AFTERNOON. A SURFACE LOW IN SOUTHEAST ALBERTA TODAY WILL
SHIFT INTO NORTHEAST MONTANA BY 06Z THURSDAY...THEN TO NEAR BEULAH
BY 12Z THURSDAY. FRONTOGENETICAL FORCING PER NAM INCREASES THIS
AFTERNOON ACROSS NORTHWEST NORTH DAKOTA. SUFFICIENT 850-300MB
OMEGA AND INCREASING SURFACE CONVERGENCE WILL LEAD TO A SLIGHT CHC
OF LIGHT FREEZING RAIN FAR NORTHWEST NORTH DAKOTA/CROSBY AREA BY
MID AFTERNOON INTO EARLY EVENING. PRECIPITATION WILL SPREAD EAST
ACROSS NORTH CENTRAL NORTH DAKOTA INTO THE TURTLE MOUNTAINS BEFORE
MIDNIGHT AND CONTINUE INTO EARLY THURSDAY MORNING. SNOWFALL
ACCUMULATIONS TONIGHT THROUGH 12Z THURSDAY WILL BE UP TO ONE INCH
FOR LOCATIONS NORTH AND EAST OF MINOT. THE THREAT OF LIGHT FREEZING
RAIN WILL EXTEND TO NEAR WILLISTON AND NEW TOWN WEDNESDAY EVENING
/00Z-03Z OR 6PM-9PM CST. THEREAFTER...THE LIGHT FREEZING RAIN THREAT
IN THE NORTH WILL END...AS THE MAIN PERCEPTION SHIELD SHIFTS EAST
INTO A MORE FAVORABLE REGIME FOR ALL SNOW. SOUNDINGS SUPPORT
PRECIPITATION AS ALL SNOW BY THE TIME THE PRECIPITATION REACHES
REACHES MINOT AND THE TURTLE MOUNTAINS.
AFTER MIDNIGHT...AS THE SURFACE LOW ENTERS WESTERN NORTH DAKOTA
AND BEGINS TO TRACK SOUTHEAST...THE BAROCLINIC ZONE WILL BEGIN TO
BE PULLED FROM NORTH TO SOUTH. AT THE SAME TIME ANOTHER SHORTWAVE
WILL SLIDE INTO SOUTHWESTERN NORTH DAKOTA FROM EASTERN MONTANA.
THE DICKINSON AND BISMARCK SOUNDINGS SUPPORT A POTENTIAL FOR A
LIGHT FREEZING RAIN MENTION FROM 09Z-15Z THURSDAY/3AM-9AM CST.
AT THIS TIME...NOT EXPECTING WIDESPREAD FREEZING RAIN NOR A HIGH
PROBABILITY/HIGH CONFIDENT FREEZING RAIN EVENT IN EITHER THE
NORTHWEST OR SOUTHWEST/SOUTH CENTRAL PRECIPITATION AREA. THUS
WILL CONTINUE TO MENTION THIS IN THE HAZARDOUS WEATHER OUTLOOK/HWO
AND LET THE DAYSHIFT HAVE ANOTHER LOOK AT THE DATA TO SEE IF THERE
ARE ANY SIGNIFICANT CHANGES FROM WHAT WAS MENTIONED ABOVE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 242 AM CST WED JAN 13 2016
THE MAIN FORECAST HIGHLIGHT IN THE LONG TERM PERIOD WILL BE
PRECIPITATION CHANCES EARLY IN THE PERIOD...THEN WIND CHILL
HIGHLIGHTS AS WE MOVE THROUGH THE WEEKEND AND EARLY NEXT WEEK.
A SHORTWAVE TROUGH MOVING ONTO THE NORTHWEST U.S. COAST THIS MORNING
WILL MOVE ACROSS THE NORTHERN ROCKIES TODAY INTO TONIGHT AND INDUCE
SURFACE LOW PRESSURE IN THE LEE OF THE NORTHERN AND CANADIAN
ROCKIES. THE SURFACE LOW IS PROGGED TO BE OVER WESTERN NORTH DAKOTA
BY 12 UTC THURSDAY. THE LOW IS FORECAST TO TRACK SOUTHEAST INTO
SOUTHERN MINNESOTA BY 00 UTC FRIDAY. MODELS ARE IN PRETTY GOOD
AGREEMENT IN SHOWING SOME INTENSIFICATION OF THE MID-LEVEL WAVE AS
IT TRACKS ACROSS NORTH DAKOTA DURING THE DAY THURSDAY. IN
ADDITION...COLDER AIR WILL BEGIN TO DROP SOUTH FROM CANADA. THE
INTERACTION OF THE COLD AIR AND STRENGTHENING WAVE WILL HELP TO
INTENSIFY THE BAROCLINIC ZONE WHICH WILL LIE ACROSS NORTHERN NORTH
DAKOTA THURSDAY MORNING. THIS IS EXPECTED TO BRING A SWATH OF 1
TO 3 INCHES OF SNOW ACROSS THE NORTHWEST AND NORTH CENTRAL AND
INTO THE NORTHERN JAMES RIVER VALLEY FROM LATE WEDNESDAY NIGHT
THROUGH THE DAY ON THURSDAY. ALWAYS CONCERNED WITH A STRENGTHENING
WAVE ALONG A TIGHT BAROCLINIC ZONE AND THE POSSIBILITY OF SOME
FRONTOGENETICALLY INDUCED BANDS OF HIGHER SNOW AMOUNTS. WILL HAVE
TO MONITOR FOR THIS POSSIBILITY AS THE MESOSCALE MODELS REACH INTO
THIS TIMEFRAME. THE 06 UTC NAM IS ALSO A BIT INTERESTING SHOWING
SOME MESOSCALE BANDING WITH HIGHER QPF AMOUNTS. FOR NOW WILL
STICK WITH A MENTION OF 1-3 INCHES OF SNOW FROM WEDNESDAY NIGHT
THROUGH THURSDAY GENERALLY ALONG AND NORTH OF A LINE FROM
WILLISTON TO MINOT AND TO RUGBY...HARVEY AND CARRINGTON. AND MAY
MENTION SOME POSSIBLY LOCAL HIGHER AMOUNTS. ANYWHERE SOUTH OF
THIS LINE COULD SEE UP TO AN INCH OF SNOW DURING THE DAY THURSDAY
AS THE BAROCLINIC ZONE DROPS SOUTH THROUGH SOUTHWEST AND SOUTH
CENTRAL NORTH DAKOTA. FOR THE MOST PART PRECIPITATION REMAINS
ALONG AND NORTH OF THE BAROCLINIC ZONE...BUT THERE IS SOME
INDICATION...MAINLY WITH THE NAM...OF SOME LIGHT PRECIPITATION
PUSHING INTO SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA FROM LATE
WEDNESDAY NIGHT INTO THURSDAY MORNING. NAM AND GFS BUFKIT SOUNDING
SHOW THAT IF ANY PRECIPITATION THURSDAY MORNING WOULD FALL OVER
THE SOUTHWEST AND SOUTH CENTRAL...THERE WOULD BE A POTENTIAL FOR
SOME LIGHT FREEZING RAIN. THIS POTENTIAL WOULD END BY MID MORNING
ACROSS MOST OF THE SOUTHWEST AND SOUTH CENTRAL...WITH THE
EXCEPTION OF THE FAR SOUTHERN TIER COUNTIES...WHERE WARMER
TEMPERATURES AT THE SURFACE AND ALOFT MAY RESULT IN A RAIN SNOW
MIX INTO THE EARLY AFTERNOON. AT THIS TIME...WE WILL KEEP A
MENTION OF MIXED PRECIPITATION SOUTHWEST AND SOUTH CENTRAL...BUT
THE MODEL QPF AMOUNTS HERE ARE QUITE LIGHT...BUT WILL CERTAINLY
NEED TO MONITOR.
LIGHT SNOW IS THEN EXPECTED TO TAPER OFF THURSDAY EVENING AS COLD
ARCTIC AIR CONTINUES TO FILTER INTO THE STATE. ANOTHER WEAK WAVE
TRACKS ALONG THE BAROCLINIC ZONE ON FRIDAY...WHICH BY THIS TIME IS
OVER WESTERN TO SOUTH CENTRAL NORTH DAKOTA. FOR NOW OUR MULTI-MODEL
BLEND IS GIVING A SPATTERING OF SLIGHT CHANCE POPS ACROSS THE CWA
WHICH SEEMS REASONABLE. IF ANYTHING WE MAY NEED TO BUMP UP POPS
ACROSS THE SOUTHWEST BUT ENOUGH TIME TO SEE HOW LATER RUNS MANIFEST
THIS.
MAIN FOCUS FRIDAY NIGHT AND THROUGH THE WEEKEND WILL BE WIND CHILL
HIGHLIGHTS...MAINLY ALONG...NORTH AND EAST OF LAKE SAKAKAWEA AND THE
MISSOURI RIVER FRIDAY NIGHT-SATURDAY MORNING...THEN ACROSS THE CWA
SATURDAY NIGHT-SUNDAY MORNING. DEPENDING ON RESULTING TEMPERATURES
WE MAY NEED A WIND CHILL WARNING ACROSS THE NORTHEASTERN PORTION OF
THE CWA DURING THIS PERIOD. COLD AIR BEGINS TO ABATE BY EARLY NEXT
WEEK BUT WILL LIKELY SEE A LARGE RANGE OF TEMPERATURES BETWEEN THE
WARMER SOUTHWEST AND COLD NORTHEAST PORTION OF THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1254 PM CST WED JAN 13 2016
LOCALIZED IFR TO LIFR CONDITIONS OVER PART OF NORTH CENTRAL ND TO
THE NORTHWEST OF KDVL WILL LIKELY CONTINUE THROUGH THE EVENING. A
BAND OF LIGHT SNOW WILL THEN DEVELOP OVER NORTH CENTRAL ND BY 00
UTC WITH LOWERING CEILINGS AND VISIBILITY. A LITTLE LIGHT FREEZING
RAIN IS POSSIBLE ON THE FRINGES OF THE SNOW...MAINLY IN NORTHWEST
ND. FLIGHT CONDITIONS WILL DETERIORATE FURTHER THURSDAY MORNING
WITH WIDESPREAD IFR TO LIFR CONDITIONS IN DEVELOPING LIGHT SNOW
ACROSS ALL OF WESTERN AND CENTRAL ND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...KS
LONG TERM...TWH
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
953 AM CST WED JAN 13 2016
.UPDATE...
ISSUED AT 953 AM CST WED JAN 13 2016
NO REAL CHANGE WITH THIS UPDATE...THOUGH WE DID UTILIZE A TIME-
LAGGED ENSEMBLE OF SHORT-RANGE MODEL GUIDANCE TO SLIGHTLY ALTER
HOURLY POPS LATE THIS AFTERNOON INTO THE EVENING. A TIME-LAGGED
ENSEMBLE OF THE LAST 3 RAP RUNS ACTUALLY SUGGESTS THE MELTING
LAYER ALOFT MAY NOT BE QUITE WARM ENOUGH FOR LIGHT FREEZING RAIN
POTENTIAL IN NORTHWEST ND LIKE WE HAVE ADVERTISED...BUT WE WILL
CERTAINLY KEEP IT IN THE FORECAST AS PRECIPITATION-TYPE ALGORITHM
OUTPUT FROM THE RAP AND OTHER GUIDANCE STILL SUPPORTS THE CHANCE.
UPDATE ISSUED AT 621 AM CST WED JAN 13 2016
NO SIGNIFICANT UPDATES THIS MORNING OTHER THAN TEMPERATURES. A
PATCH OF CLEAR SKIES ACROSS CENTRAL NORTH DAKOTA HAS ALLOWED
TEMPERATURES TO FALL INTO THE SINGLE DIGITS WHILE CLOUDS
ASSOCIATED WITH A QUICK MOVING SHORTWAVE IN EASTERN PORTION OF
CENTRAL NORTH DAKOTA HAVE CAUSED TEMPERATURES TO RISE THERE FROM
EARLIER LOWS IN THE SINGLE DIGITS. FARTHER WEST...MORE MILD AIR
HAS MOVED INTO THE FAR WEST WITH TEMPERATURES GENERALLY IN THE
TEENS NORTHWEST TO 20S SOUTHWEST. LIGHT SNOW HAS ENDED OVER
EASTERN PORTIONS OF CENTRAL NORTH DAKOTA. WILL UPDATE CURRENT LOW
TEMPERATURES AND BLEND THROUGH MID MORNING. UPDATED TEXT PRODUCTS
WILL BE SENT SHORTLY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 242 AM CST WED JAN 13 2016
MAIN CONCERNS IN THE SHORT TERM IS PRECIPITATION TYPE...WHICH
COMES IN TWO DISTINCT AREAS...ONE AREA IN NORTHWEST THROUGH NORTH
CENTRAL/TURTLE MOUNTAINS LATER THIS AFTERNOON THROUGH TONIGHT...AND
THE SECOND AREA DEVELOPING AFTER MIDNIGHT INTO MID MORNING THURSDAY
ACROSS SOUTHWEST AND INTO SOUTH CENTRAL NORTH DAKOTA.
MODEL CONSENSUS ON TIMING AND COVERAGE OF PRECIPITATION STILL
SUSPECT...HOWEVER THE IDEA OF TWO PRECIPITATION AREAS WITH THE
POTENTIAL FOR BOTH LIGHT FREEZING RAIN AND SNOW IS WELL AGREED
UPON PER NAM/GFS/SREF BUFKIT SOUNDINGS. HENCE USED A BLEND OF
THESE SOUNDINGS FOR THE AREAS MENTIONED ABOVE TO ADJUST THE
GIVEN SUPERBLEND WEATHER GRIDS.
CURRENT SUITE OF SATELLITE IMAGERY SHOWS A BREAK IN THE OVERCAST
CONDITIONS FOR WESTERN AND MOST OF CENTRAL NORTH DAKOTA EARLY THIS
MORNING. THE EXCEPTION IS THE TURTLE MOUNTAINS AND INTO THE JAMES
RIVER VALLEY WHERE A FAST MOVING SHORTWAVE EXTENDING FROM SOUTHWEST
MANITOBA WAS GENERATING CLOUDS AND PERIODIC WAVES OF LIGHT SNOW
MOSTLY FROM ROLETTE COUNTY EASTWARD. THIS ACTIVITY WILL WANE
AFTER 12Z WEDS AS THE SHORTWAVE SHIFTS FARTHER EAST. HIGH CLOUDS
QUICKLY INCREASING ACROSS CENTRAL/EASTERN MONTANA INDICATIVE OF
THE NEXT SURGE OF WARM AIR ADVECTION. SHOULD SEE SOME SUNSHINE
EARLY TODAY THEN CLOUDING UP FROM NORTHWEST TO SOUTHEAST. A
BAROCLINIC ZONE WAS SITUATED FROM NORTHWEST INTO NORTH CENTRAL
NORTH DAKOTA/TURTLE MOUNTAINS...AND SOUTHEAST INTO THE NORTHERN
JAMES RIVER VALLEY THIS MORNING. EXPECT A DISTINCT HIGH TEMPERATURE
FORECAST TODAY WITH HIGHS IN THE LOWER 40S FAR SOUTHWEST TO MID-
TEENS IN THE TURTLE MOUNTAINS AS THE BAROCLINIC ZONE TIGHTENS UP
THIS AFTERNOON. A SURFACE LOW IN SOUTHEAST ALBERTA TODAY WILL
SHIFT INTO NORTHEAST MONTANA BY 06Z THURSDAY...THEN TO NEAR BEULAH
BY 12Z THURSDAY. FRONTOGENETICAL FORCING PER NAM INCREASES THIS
AFTERNOON ACROSS NORTHWEST NORTH DAKOTA. SUFFICIENT 850-300MB
OMEGA AND INCREASING SURFACE CONVERGENCE WILL LEAD TO A SLIGHT CHC
OF LIGHT FREEZING RAIN FAR NORTHWEST NORTH DAKOTA/CROSBY AREA BY
MID AFTERNOON INTO EARLY EVENING. PRECIPITATION WILL SPREAD EAST
ACROSS NORTH CENTRAL NORTH DAKOTA INTO THE TURTLE MOUNTAINS BEFORE
MIDNIGHT AND CONTINUE INTO EARLY THURSDAY MORNING. SNOWFALL
ACCUMULATIONS TONIGHT THROUGH 12Z THURSDAY WILL BE UP TO ONE INCH
FOR LOCATIONS NORTH AND EAST OF MINOT. THE THREAT OF LIGHT FREEZING
RAIN WILL EXTEND TO NEAR WILLISTON AND NEW TOWN WEDNESDAY EVENING
/00Z-03Z OR 6PM-9PM CST. THEREAFTER...THE LIGHT FREEZING RAIN THREAT
IN THE NORTH WILL END...AS THE MAIN PERCEPTION SHIELD SHIFTS EAST
INTO A MORE FAVORABLE REGIME FOR ALL SNOW. SOUNDINGS SUPPORT
PRECIPITATION AS ALL SNOW BY THE TIME THE PRECIPITATION REACHES
REACHES MINOT AND THE TURTLE MOUNTAINS.
AFTER MIDNIGHT...AS THE SURFACE LOW ENTERS WESTERN NORTH DAKOTA
AND BEGINS TO TRACK SOUTHEAST...THE BAROCLINIC ZONE WILL BEGIN TO
BE PULLED FROM NORTH TO SOUTH. AT THE SAME TIME ANOTHER SHORTWAVE
WILL SLIDE INTO SOUTHWESTERN NORTH DAKOTA FROM EASTERN MONTANA.
THE DICKINSON AND BISMARCK SOUNDINGS SUPPORT A POTENTIAL FOR A
LIGHT FREEZING RAIN MENTION FROM 09Z-15Z THURSDAY/3AM-9AM CST.
AT THIS TIME...NOT EXPECTING WIDESPREAD FREEZING RAIN NOR A HIGH
PROBABILITY/HIGH CONFIDENT FREEZING RAIN EVENT IN EITHER THE
NORTHWEST OR SOUTHWEST/SOUTH CENTRAL PRECIPITATION AREA. THUS
WILL CONTINUE TO MENTION THIS IN THE HAZARDOUS WEATHER OUTLOOK/HWO
AND LET THE DAYSHIFT HAVE ANOTHER LOOK AT THE DATA TO SEE IF THERE
ARE ANY SIGNIFICANT CHANGES FROM WHAT WAS MENTIONED ABOVE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 242 AM CST WED JAN 13 2016
THE MAIN FORECAST HIGHLIGHT IN THE LONG TERM PERIOD WILL BE
PRECIPITATION CHANCES EARLY IN THE PERIOD...THEN WIND CHILL
HIGHLIGHTS AS WE MOVE THROUGH THE WEEKEND AND EARLY NEXT WEEK.
A SHORTWAVE TROUGH MOVING ONTO THE NORTHWEST U.S. COAST THIS MORNING
WILL MOVE ACROSS THE NORTHERN ROCKIES TODAY INTO TONIGHT AND INDUCE
SURFACE LOW PRESSURE IN THE LEE OF THE NORTHERN AND CANADIAN
ROCKIES. THE SURFACE LOW IS PROGGED TO BE OVER WESTERN NORTH DAKOTA
BY 12 UTC THURSDAY. THE LOW IS FORECAST TO TRACK SOUTHEAST INTO
SOUTHERN MINNESOTA BY 00 UTC FRIDAY. MODELS ARE IN PRETTY GOOD
AGREEMENT IN SHOWING SOME INTENSIFICATION OF THE MID-LEVEL WAVE AS
IT TRACKS ACROSS NORTH DAKOTA DURING THE DAY THURSDAY. IN
ADDITION...COLDER AIR WILL BEGIN TO DROP SOUTH FROM CANADA. THE
INTERACTION OF THE COLD AIR AND STRENGTHENING WAVE WILL HELP TO
INTENSIFY THE BAROCLINIC ZONE WHICH WILL LIE ACROSS NORTHERN NORTH
DAKOTA THURSDAY MORNING. THIS IS EXPECTED TO BRING A SWATH OF 1
TO 3 INCHES OF SNOW ACROSS THE NORTHWEST AND NORTH CENTRAL AND
INTO THE NORTHERN JAMES RIVER VALLEY FROM LATE WEDNESDAY NIGHT
THROUGH THE DAY ON THURSDAY. ALWAYS CONCERNED WITH A STRENGTHENING
WAVE ALONG A TIGHT BAROCLINIC ZONE AND THE POSSIBILITY OF SOME
FRONTOGENETICALLY INDUCED BANDS OF HIGHER SNOW AMOUNTS. WILL HAVE
TO MONITOR FOR THIS POSSIBILITY AS THE MESOSCALE MODELS REACH INTO
THIS TIMEFRAME. THE 06 UTC NAM IS ALSO A BIT INTERESTING SHOWING
SOME MESOSCALE BANDING WITH HIGHER QPF AMOUNTS. FOR NOW WILL
STICK WITH A MENTION OF 1-3 INCHES OF SNOW FROM WEDNESDAY NIGHT
THROUGH THURSDAY GENERALLY ALONG AND NORTH OF A LINE FROM
WILLISTON TO MINOT AND TO RUGBY...HARVEY AND CARRINGTON. AND MAY
MENTION SOME POSSIBLY LOCAL HIGHER AMOUNTS. ANYWHERE SOUTH OF
THIS LINE COULD SEE UP TO AN INCH OF SNOW DURING THE DAY THURSDAY
AS THE BAROCLINIC ZONE DROPS SOUTH THROUGH SOUTHWEST AND SOUTH
CENTRAL NORTH DAKOTA. FOR THE MOST PART PRECIPITATION REMAINS
ALONG AND NORTH OF THE BAROCLINIC ZONE...BUT THERE IS SOME
INDICATION...MAINLY WITH THE NAM...OF SOME LIGHT PRECIPITATION
PUSHING INTO SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA FROM LATE
WEDNESDAY NIGHT INTO THURSDAY MORNING. NAM AND GFS BUFKIT SOUNDING
SHOW THAT IF ANY PRECIPITATION THURSDAY MORNING WOULD FALL OVER
THE SOUTHWEST AND SOUTH CENTRAL...THERE WOULD BE A POTENTIAL FOR
SOME LIGHT FREEZING RAIN. THIS POTENTIAL WOULD END BY MID MORNING
ACROSS MOST OF THE SOUTHWEST AND SOUTH CENTRAL...WITH THE
EXCEPTION OF THE FAR SOUTHERN TIER COUNTIES...WHERE WARMER
TEMPERATURES AT THE SURFACE AND ALOFT MAY RESULT IN A RAIN SNOW
MIX INTO THE EARLY AFTERNOON. AT THIS TIME...WE WILL KEEP A
MENTION OF MIXED PRECIPITATION SOUTHWEST AND SOUTH CENTRAL...BUT
THE MODEL QPF AMOUNTS HERE ARE QUITE LIGHT...BUT WILL CERTAINLY
NEED TO MONITOR.
LIGHT SNOW IS THEN EXPECTED TO TAPER OFF THURSDAY EVENING AS COLD
ARCTIC AIR CONTINUES TO FILTER INTO THE STATE. ANOTHER WEAK WAVE
TRACKS ALONG THE BAROCLINIC ZONE ON FRIDAY...WHICH BY THIS TIME IS
OVER WESTERN TO SOUTH CENTRAL NORTH DAKOTA. FOR NOW OUR MULTI-MODEL
BLEND IS GIVING A SPATTERING OF SLIGHT CHANCE POPS ACROSS THE CWA
WHICH SEEMS REASONABLE. IF ANYTHING WE MAY NEED TO BUMP UP POPS
ACROSS THE SOUTHWEST BUT ENOUGH TIME TO SEE HOW LATER RUNS MANIFEST
THIS.
MAIN FOCUS FRIDAY NIGHT AND THROUGH THE WEEKEND WILL BE WIND CHILL
HIGHLIGHTS...MAINLY ALONG...NORTH AND EAST OF LAKE SAKAKAWEA AND THE
MISSOURI RIVER FRIDAY NIGHT-SATURDAY MORNING...THEN ACROSS THE CWA
SATURDAY NIGHT-SUNDAY MORNING. DEPENDING ON RESULTING TEMPERATURES
WE MAY NEED A WIND CHILL WARNING ACROSS THE NORTHEASTERN PORTION OF
THE CWA DURING THIS PERIOD. COLD AIR BEGINS TO ABATE BY EARLY NEXT
WEEK BUT WILL LIKELY SEE A LARGE RANGE OF TEMPERATURES BETWEEN THE
WARMER SOUTHWEST AND COLD NORTHEAST PORTION OF THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 621 AM CST WED JAN 13 2016
VFR CIGS/VSBYS EXPECTED AT ALL TERMINALS THROUGH 00Z THURSDAY.
THEREAFTER...CIGS WILL BEGIN TO DETERIORATE TO MVFR/IFR FROM NORTH
TO SOUTH. MVFR CIGS EXPECTED AT KMOT BY 01Z THURSDAY WITH LIGHT SNOW
DEVELOPING BY 05Z REDUCING VSBYS TO MVFR/IFR. THE REST OF THE
TERMINALS WILL TAKE A DOWNWARD TREND TO MVFR/IFR BETWEEN 09Z-12Z
THURSDAY. LIGHT FREEZING RAIN POSSIBLE AT KDIK/KBIS BETWEEN 09Z-15Z
THURSDAY BUT LOW CONFIDENCE THIS FAR OUT TO MENTION AS A PREDOMINATE
FORECAST ELEMENT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1136 PM CST TUE JAN 12 2016
.UPDATE...
ISSUED AT 1136 PM CST TUE JAN 12 2016
THE LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE DIVING SOUTHEAST
FROM SOUTHERN SASKATCHEWAN...FORECAST TO MOVE INTO THE TURTLE
MOUNTAINS AND EXTEND INTO THE NORTHERN JAMES RIVER VALLEY 12Z
WEDNESDAY. REGIONAL RADAR SHOWS WEAK REFLECTIVITY`S SLIDING
THROUGH ROLETTE COUNTY. SURFACE OBSERVATIONS AT ROLLA MUNICIPAL
AIRPORT NOT INDICATING PRECIPITATION REACHING THE GROUND AS OF
THIS WRITING...BUT WITH CEILINGS AT 5000FT IT IS JUST A MATTER OF
TIME. CURRENT GRIDS HAVE THIS HANDLED WELL. A MOSTLY CLEAR SKY WAS
TAKING SHAPE IN THE WEST WITH HIGH CLOUDS ADVANCING THROUGH
CENTRAL/EASTERN MONTANA. OVERCAST CONDITIONS CENTRAL NORTH DAKOTA
WILL GRADUALLY IMPROVE TO PARTLY CLOUDY REST OF TONIGHT EXCEPT
FROM THE TURTLE MOUNTAINS INTO THE JAMES RIVER VALLEY WITH THE
ASSOCIATED SHORTWAVE MENTIONED ABOVE. MINOR UPDATES TO SKY GRIDS
WITH THE OVERALL FORECAST IN GOOD STANDING.
UPDATE ISSUED AT 929 PM CST TUE JAN 12 2016
SOME LIGHT ECHOS ON RADAR ARE STARTING TO SHOW UP OVER FAR NORTH
CENTRAL NORTH DAKOTA. FOR LATE EVENING UPDATE HAVE ADDRESSED THIS
BY STARTING LOW CHANCES FOR SNOW NOW...WHICH IS A BIT EARLIER THAN
PREVIOUS FORECAST. OTHERWISE...BESIDES ADJUSTING CLOUD COVER
TOWARDS CURRENT SATELLITE TRENDS REMAINDER OF FORECAST WAS IN GOOD
SHAPE.
UPDATE ISSUED AT 604 PM CST TUE JAN 12 2016
FOR EARLY EVENING UPDATE HAVE ADDED LOW CHANCES FOR SNOW OVER THE
FAR SOUTHWEST AS WEAK WAVE MOVES THROUGH AND SOME WEAK ECHOS ARE
SHOWING UP ON THE BOWMAN NDARB RADAR. ONLY OTHER CHANGE WAS TO
INCREASE CLOUD COVER THROUGH THE EVENING AS SATELLITE HAS MOST OF
THE AREA UNDER OVERCAST SKIES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 245 PM CST TUE JAN 12 2016
LOW-END PRECIPITATION CHANCES AND A STARK TEMPERATURE CONTRAST
FROM NORTH CENTRAL TO SOUTHWEST ND HIGHLIGHT THE SHORT TERM.
LIGHT SNOW FROM NORTHWEST INTO SOUTH CENTRAL ND HAS BEEN ON A
STEADY WEAKENING TREND SINCE ABOUT 19 UTC...AND IS EXPECTED TO
DIMINISH FURTHER BY LATE AFTERNOON AS ASCENT DROPS OFF. WE ARE
THEN CARRYING ANOTHER SLIGHT CHANCE OF LIGHT SNOW LATE TONIGHT
FROM BOTTINEAU TOWARD RUGBY AND ROLLA OUT OF RESPECT TO A WEAK
SHORTWAVE TROUGH IN NORTHWEST FLOW ALOFT THAT WILL CLIP THAT
AREA AFTER 06 UTC.
INTERESTINGLY...BOTH THE OPERATIONAL AND EXPERIMENTAL /ESRL-RUN/
HRRR FLAVORS HAVE BEEN SIMULATING DENSE FOG DEVELOPMENT ACROSS
CENTRAL ND TONIGHT. THEY ARE ON THEIR OWN IN THIS EXPECTATION AS
NEITHER THE 12 UTC NAM-NEST OR POINT-BASED MOS GUIDANCE /MAV OR
MET OUTPUT/ SUGGEST THIS SCENARIO. CLOSER INSPECTION SHOWED THE
HRRR SIMULATIONS DEVELOP THIS FOG OVER LAKE SAKAKAWEA AND THEN
ADVECT IT DOWNSTREAM ON LIGHT WIND FIELDS. SKIN TEMPERATURES IN
THE HRRR SIMULATIONS ARE ABOVE 40 F OVER LAKE SAKAKAWEA...WHICH
MEANS THEY ARE ASSUMING MUCH MORE OPEN WATER EXISTS THAN DOES IN
REALITY. THUS...WE BELIEVE THAT THE HRRR GUIDANCE IS LIKELY
OVERZEALOUS WITH ITS EXPECTATION OF FOG AND LOW CLOUD FORMATION.
ON WEDNESDAY...STRONGER MID-LEVEL WARM AIR ADVECTION WILL OCCUR
AND PUSH 850-MB TEMPERATURES TO +2 TO +4 C SOUTH AND WEST OF THE
MISSOURI RIVER BY AFTERNOON. THE RESULT WILL BE HIGHS ABOVE 32 F
IN THOSE AREAS...CONTRASTED BY HIGHS ONLY IN THE TEENS F ACROSS
ROLETTE COUNTY. THE LOW- TO MID-LEVEL WARM FRONTAL BOUNDARY THAT
WILL SEPARATE THOSE AIR MASSES COULD SERVE AS A FOCUS FOR LIGHT
PRECIPITATION BY LATE DAY AS ANOTHER SHORTWAVE TROUGH APPROACHES
THE AREA. THE 12 UTC MULTI-MODEL CONSENSUS SUPPORTED POPS OF 20
TO 30 PERCENT OVER NORTHWEST ND BY LATE AFTERNOON...AND WE CHOSE
TO CONTINUE WITH A SLIGHT CHANCE OF LIGHT FREEZING IN THE WATFORD
CITY AND WILLISTON AREAS BASED ON EXPECTED TEMPERATURES ALOFT. WE
KEPT THE FORECAST DRY OVER SOUTH CENTRAL ND GIVEN A DRY BOUNDARY
LAYER...BUT THE 12 UTC NCEP WRF-ARW SIMULATED LIGHT PRECIPITATION
INTO THE BISMARCK AREA BY VERY LATE AFTERNOON...WHICH REPRESENTS
A VERY LOW-END...BUT NON-ZERO RISK OF LIGHT FREEZING RAIN. WE DID
NOT INCLUDE THAT IN THE OFFICIAL FORECAST AT THIS POINT FOR THAT
AREA THOUGH SINCE THE PROBABILITY OF OCCURRENCE IS VERY LOW.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 207 PM CST TUE JAN 12 2016
THE MAIN ISSUES IN THE LONG TERM ARE SNOW CHANCES FOR THE END OF
THE WEEK AND DANGEROUS COLD THIS WEEKEND.
A CLIPPER WILL APPROACH NORTH DAKOTA WEDNESDAY EVENING.
PRECIPITATION IS EXPECTED TO FORM ACROSS A PERSISTENT BAROCLINIC
ZONE BISECTING NORTH DAKOTA. THE 12 UTC MODELS ARE IN FAIRLY GOOD
AGREEMENT IN SPREADING 1 TO 2 INCHES OF SNOW ACROSS NORTHERN NORTH
DAKOTA...WITH THE HIGHEST AMOUNTS CONFINED TO THE TURTLE
MOUNTAINS. LIGHT SNOW IS EXPECTED TO BEGIN ACROSS FAR NORTHWEST
NORTH DAKOTA WEDNESDAY EVENING AND SPREAD SOUTHEAST THROUGH
WEDNESDAY NIGHT INTO THURSDAY MORNING. THE BAROCLINIC ZONE WILL
SHIFT FURTHER SOUTHWEST THURSDAY AND FRIDAY...AND THEREFORE SNOW
CHANCES WILL ALSO SHIFT FROM NORTHERN NORTH DAKOTA TO SOUTHWEST
NORTH DAKOTA. HOWEVER...WITH THESE QUICK MOVING WAVES ONLY LIGHT
QPF AMOUNTS ARE EXPECTED...SO LITTLE TO NO IMPACTS ARE
ANTICIPATED.
ANOTHER DEEP GREAT LAKES TROUGH IS EXPECTED TO FORM BY THIS
WEEKEND. THIS WILL ALLOW BITTERLY COLD ARCTIC AIR TO PUSH INTO
NORTH DAKOTA. THERE IS SOME UNCERTAINTY AS TO EXACTLY WHEN THE
SURFACE HIGH AND COLDEST AIR WILL SETTLE ACROSS NORTH DAKOTA.
HOWEVER...IT APPEARS TEMPERATURES WELL BELOW ZERO ARE
LIKELY...WITH WIND CHILLS POTENTIALLY REACHING THE 20S AND 30S
BELOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1136 PM CST TUE JAN 12 2016
VFR CIGS/VSBYS EXPECTED AT ALL TERMINALS THROUGH MOST OF THIS TAF
PERIOD. THE EXCEPTION WILL BE AT KISN/KMOT...BETWEEN 03Z AND 06Z
THURSDAY...AS MVFR CIGS WILL RETURN. AN AREA OF SNOW IS ALSO
POSSIBLE NEAR KISN/KMOT 06Z-12Z THURSDAY AND WILL ADDRESS THIS IN
THE NEXT TAF FORECAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...CJS
LONG TERM...AJ
AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
415 PM EST WED JAN 13 2016
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE MOVING ACROSS THE GREAT LAKES WILL RESULT
IN SOME LIGHT SNOW INTO THIS EVENING...MAINLY ALONG AND NORTH OF
INTERSTATE 70. SOUTHERLY FLOW WILL ALLOW FOR A GRADUAL WARM UP
THURSDAY INTO FRIDAY. ANOTHER UPPER LEVEL DISTURBANCE WILL BRING
RAIN TO THE AREA ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AN AREA OF LIGHT SNOW AND FLURRIES HAS SPREAD INTO NORTHERN
PORTIONS OF OUR FA THIS AFTERNOON IN ASSOCIATION WITH A WEAK
UPPER LEVEL DISTURBANCE. VSBYS HAVE BEEN OCCASIONALLY DROPPING
BELOW A COUPLE OF MILES...SO THINK SOME LIGHT ACCUMULATIONS WILL
BE POSSIBLE ACROSS OUR FAR NORTH...BUT SHOULD BE LESS THAN A HALF
INCH. EXPECT PCPN TO TAPER OF FROM WEST TO EAST THROUGH THIS
EVENING AS WE GET ON THE BACK SIDE OF THE DISTURBANCE. IN
DEVELOPING SOUTHERLY LOW LEVEL FLOW...EXPECT TEMPS TO SLOWLY RISE
UP INTO THE MID 20S OVERNIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
IN CONTINUED SOUTHERLY FLOW...LOW LEVEL MOISTURE WILL BE ON THE
INCREASE THROUGH THE MORNING HOURS ON THURSDAY. THE 12Z GFS IS
ACTUALLY THE MOST AGGRESSIVE WITH THIS...EVEN TRYING TO SQUEEZE
OUT SOME VERY LIGHT QPF THROUGH THE MORNING HOURS. THE 12Z NAM IS
ALSO TRYING TO SUGGEST THIS...BUT IS SHALLOWER WITH ITS NEAR
SURFACE SATURATED LAYER WHILE THE LATEST RAP IS EVEN LESS
IMPRESSIVE. AS A RESULT...THERE IS QUITE A BIT OF UNCERTAINTY IN
THE POSSIBILITY FOR SOME PATCHY FREEZING DRIZZLE/DRIZZLE THURSDAY
MORNING. SINCE IT IS TOUGH TO RULE IT OUT THOUGH AND IS ALREADY IN
THE FORECAST...WILL GO AHEAD AND HANG ON TO JUST A VERY LOW
CHANCE.
SOUTHERLY FLOW WILL CONTINUE TO INCREASE THURSDAY NIGHT INTO
FRIDAY AHEAD OF AN APPROACHING MID LEVEL SHORT WAVE. THIS WILL
ALLOW FOR DEEPER MOISTURE TO SPREAD NORTH INTO OUR AREA ON FRIDAY.
BETWEEN THIS AND SOME DEVELOPING ISENTROPIC LIFT...EXPECT TO SEE
SOME PCPN WORKING INTO OUR FAR SOUTHWEST POSSIBLY AS EARLY AS
LATE THURSDAY NIGHT AND THEN OVERSPREADING OUR AREA FRIDAY
MORNING AND CONTINUING INTO FRIDAY AFTERNOON. LOW LEVEL THERMAL
FIELDS OFF FORECAST SOUNDINGS SUGGEST THAT WE WILL BE WARM ENOUGH
FOR PRECIPITATION TO BE ALL LIQUID AT ONSET LATE THURSDAY
NIGHT/FRIDAY MORNING. SURFACE TEMPERATURES SHOULD ALSO BE ABOVE
FREEZING SO WILL KEEP PCPN ALL RAIN.
PCPN WILL BEGIN TO TAPER OFF FROM WEST TO EAST FRIDAY NIGHT AS
DRIER AIR FILTERS IN BEHIND A COLD FRONT MOVING THROUGH THE AREA.
AS THE COOLER AIR MOVES IN...SOME OF THE PCPN WILL MIX WITH AND
THEN CHANGE TO SNOW THROUGH THE NIGHT...BUT GIVEN THE DECREASING
MOISTURE...QPF AMOUNTS SHOULD BE FAIRLY LIGHT BY THEN.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE LONG TERM PERIOD STARTS OFF WITH LOW PRESSURE HEADING TOWARDS
THE NORTHEAST AND THE POTENTIAL FOR WRAP AROUND SNOW SATURDAY. A
STRONG UPPER LEVEL LOW WILL THEN BEGIN TO ROTATE SOUTHWARDS SATURDAY
EVENING INTO SUNDAY MORNING BRINGING AN ARCTIC COLD FRONT THROUGH
THE REGION. THERE ARE SOME SLIGHT DIFFERENCES BETWEEN THE EURO...
GFS... AND CMC WHICH ALL HAVE CORRESPONDING IMPACTS ON THE TIMING OF
THE ARCTIC FRONT AND IF THERE WILL BE ASSOCIATED PRECIPITATION.
DIFFERENCES START TO OCCUR EARLY SATURDAY MORNING AS A POTENT
SHORTWAVE DIPS DOWN INTO THE TEXAS PANHANDLE.
THE GFS STRENGTHENS THE SHORTWAVE AND STARTS TO SLOW IT DOWN AS IT
PUSHES EAST INTO LOUISIANA SATURDAY EVENING. THE EURO AND CANADIAN
KEEP THE SHORTWAVE MUCH WEAKER AND THE UPPER LEVEL LOW A TAD FURTHER
SOUTH. THE EURO/ CMC SOLUTION FAVORS THE ARCTIC COLD FRONT MOVING
THROUGH THE AREA SATURDAY EVENING. THE GFS SOLUTION HAS THE ARCTIC
FRONT MOVING THROUGH SUNDAY MORNING. GIVEN THE CMC AND EURO ARE A
RELATIVELY CLOSE MATCH HAVE LEANED TOWARDS THIS SOLUTION.
DURING THE DAY SUNDAY 850 MB TEMPERATURES BEGIN TO PLUMMET FROM -7
DEGREES C SATURDAY TO NEAR -20 DEGREES C SUNDAY. THIS WILL MAKE HIGH
TEMPERATURES IN THE TEENS POSSIBLE SUNDAY AS THICKNESSES QUICKLY
FALL. FOR NOW HAVE GONE AHEAD AND JUST TRENDED MAX TEMPS DOWN A BIT
TO FAVOR CMC/EURO. ALSO WITH THE FURTHER SOUTH UPPER LEVEL LOW TRACK
THERE LOOKS TO BE A CHANCE OF SNOW AS STRONG PVA MOVES ACROSS THE
AREA. HAVE BUMPED UP POPS TO CHANCE FOR SUNDAY. MONDAY MORNING
SURFACE HIGH PRESSURE WILL START TO MOVE INTO THE AREA AS THE BEST
AGEOSTROPHIC CONVERGENCE MOVES EAST TOWARDS THE REGION. HIGHS MONDAY
WILL BE WELL BELOW NORMAL AS THE MERCURY ONLY RISES TO THE MIDDLE
TEENS. THIS IS SUPPORTED BY 850 TEMPERATURES AGAIN FORECASTED TO BE
AROUND -20 DEGREES C.
TUESDAY INTO WEDNESDAY THE WARMING TREND WILL START TO COMMENCE AS
SURFACE HIGH PRESSURE SLOWLY SLIDES EAST OF OHIO ALLOWING SOUTHERLY
WINDS TO RETURN. LATE TUESDAY INTO EARLY WEDNESDAY A SHORTWAVE WILL
DIVE SOUTH INTO NORTHERN WISCONSIN AND JUST CLIP NORTHERN OHIO. FOR
NOW HAVE JUST ADDED SLIGHT CHANCE POPS ACROSS THE NORTH TO ACCOUNT
FOR THIS. DURING THE DAY WEDNESDAY MODELS ARE INDICATING A STRONG
SHORTWAVE TRYING TO WRAP UP OVER THE ROCKY MOUNTAINS. THIS LIKELY BE
THE NEXT STORM SYSTEM TO AFFECT THE AREA.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
SURFACE HIGH PRESSURE CENTERED OVER THE TN VLY WILL SLIDE EAST
WITH WAA DEVELOPING ON ITS BACK SIDE. MID LEVEL CLOUDS VISIBLE
ON LATEST SATL IMGRY IN THIS REGION OF ISENTROPIC LIFT SHIFTING
EAST ACRS IL AND INDIANA INTO WESTERN OHIO. BEST MOISTURE/LIFT TO
STAY NORTH OF THE TAF SITES BUT A BRIEF PERIOD OF LIGHT SNOW OR
FLURRIES WILL BE PSBL AT KDAY AND KCMH/KLCK TOWARD 00Z. EXPECT VFR
CONDITIONS THRU MOST OF THE NIGHT AS MID LEVEL CLOUDS GIVE WAY TO
PARTIAL CLEARING. IN SOUTHERLY FLOW...LOW LEVEL MOISTURE INCREASES
TOWARD SUNRISE. HAVE INTRODUCED MVFR CIGS AT ALL TAF SITES.
OUTLOOK...MVFR CEILINGS ARE LIKELY THURSDAY NIGHT AND MVFR CIGS
AND VISIBILITIES LIKELY FRIDAY INTO SATURDAY. MVFR CEILINGS MAY
LINGER INTO SATURDAY NIGHT AND SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...FRANKS
AVIATION...AR
AREA FORECAST DISCUSSION...CORRECTED
NWS PORTLAND OR
946 PM PST TUE JAN 12 2016
.SYNOPSIS...THE PACIFIC NORTHWEST IS MOVING BACK INTO A WET WEATHER
REGIME WHICH WILL LAST FOR THE NEXT SEVERAL DAYS...AS SEVERAL LOW
PRESSURE AND ASSOCIATED FRONTAL SYSTEMS ARE FORECAST TO MOVE THROUGH
THE REGION. THE LATEST LOW PRESSURE SYSTEM IS MOVING UP THE PAC NW
COAST THIS EVENING...WITH STEADY RAIN THIS EVENING EXPECTED TO TAPER
TO SHOWERS BY WEDNESDAY MORNING AS A COLD FRONT SLOWLY MOVES ONSHORE.
SNOW LEVELS WILL FALL BACK BELOW THE CASCADE PASSES BEHIND THE FRONT
WEDNESDAY. THE NEXT SYSTEM IMPACTS THE REGION THURSDAY AND THURSDAY
NIGHT AND HAS THE POTENTIAL TO BRING SEVERAL INCHES OF SNOW TO THE
CASCADES. ADDITIONAL FRONTS ARE EXPECTED OVER THE WEEKEND AND EARLY
NEXT WEEK...KEEPING WET WEATHER IN THE FORECAST.
&&
.EVENING UPDATE...STEADY LIGHT TO MODERATE RAIN HAS AFFECTED THE
MAJORITY OF THE FORECAST AREA FOR MUCH OF THE DAY...ADDING UP TO
ABOUT AN INCH FOR MOST OF THE LOWLANDS AND ABOUT 2 INCHES IN THE
HIGHER TERRAIN. THIS IS BEING CAUSED BY PERSISTENT ISENTROPIC LIFT AS
WARM...MOIST AIR OVERRUNS COOLER AIR ENTRENCHED NEAR THE SURFACE. LOW
PRESSURE OFFSHORE HAS BEEN DRIVING THE SOUTHERLY FLOW ALOFT WHICH IS
PARTIALLY RESPONSIBLE FOR THE ISENTROPIC LIFT. THE INTENSITY AND
LOCATION OF THIS LOW CENTER HAVE BEEN PRETTY HARD TO PIN DOWN
OVERNIGHT...BOTH FOR FORECASTERS AND FOR THE MODELS. IT APPEARS THAT
AS OF 9 PM THE LOW CENTER IS AROUND 997 MB...ABOUT 20 TO 30 MILES
OFFSHORE FROM ASTORIA. THIS LOW BROUGHT A QUICK BUT IMPRESSIVE SURGE
OF WIND TO BUOY 46050...WITH A GUST UP TO 52 KT OR 59 MPH. HOWEVER IT
APPEARS THE EASTERLY COMPONENT TO THE SURFACE GRADIENTS HAS KEPT THE
STRONGEST SFC WINDS OFFSHORE. THE STRONGEST COASTAL GUSTS HAVE BEEN
IN THE 40-50 MPH RANGE...DESPITE 60-70 KT WINDS SHOWING UP JUST
1000-2000 FT ABOVE THE SURFACE ACCORDING TO THE ESRL ASTORIA
PROFILER. BETTER MIXING IS POSSIBLE TONIGHT AS THE COAST BRIEFLY GETS
INTO THE WARM SECTOR...BUT THE STRONGEST SOUTH TO NORTH GRADIENTS
APPEAR TO BE RATHER COMPACT AND CLOSE TO THE LOW CENTER. A SECONDARY
LOW MOVING ONSHORE NEAR THE OR/CA BORDER APPEARS TO BE ROBBING THE
OVERALL GRADIENTS A BIT...AND THUS THE STRONGEST WIND THREAT. DECIDED
TO CANCEL THE HIGH WIND WARNING FOR OUR OREGON COAST ZONES...IT WILL
STILL BE WINDY WITH 40-50 MPH GUSTS BUT WINDS SHOULD REMAIN BELOW
WARNING CRITERIA.
MEANWHILE COLD AIR REMAINS ENTRENCHED EAST OF THE CASCADE CREST...
KEEPING SNOW LEVELS FAIRLY LOW NORTH AND EAST OF MOUNT HOOD. RECEIVED
A PUBLIC REPORT OF 7 INCHES OF SNOW AT TROUT LAKE A COUPLE HOURS
AGO...AND WEBCAMS IN THE AREA SEEM TO CONFIRM THIS. ENOUGH WARM AIR
HAS MOVED IN ALOFT TO SWITCH THE PRECIPITATION TO RAIN IN THE HOOD
RIVER VALLEY...BUT TEMPS REMAIN STUBBORNLY NEAR FREEZING IN UPPER
PORTIONS OF THE VALLEY SO THERE ARE LIKELY SOME POCKETS OF FREEZING
RAIN. SOUTH OF MOUNT HOOD...SNOW LEVELS HAVE SKYROCKETED TO 6000 TO
7000 FEET...SO THE CASCADE PASSES ARE JUST EXPERIENCING RAIN AT THE
MOMENT. WILL EXTEND THE WINTER WX ADVISORY FOR THE UPPER HOOD RIVER
VALLEY UNTIL 4 AM...WHICH IS WHEN THE LAST COUPLE RUNS OF THE HRRR
MODEL SUGGEST THE STEADY PRECIPITATION WILL WIND DOWN OVER THE HOOD
RIVER VALLEY. THERE WILL PROBABLY BE LESS OF A DISTINCT BREAK IN
PRECIP OVER THE S WA CASCADES...WITH MOST MODELS SUGGESTING A
RESURGENCE OF PRECIPITATION WITH A COLD FRONT WED MORNING. THEREFORE
WE EXTENDED THE ADVISORY FOR THE S WA CASCADES UNTIL 2 PM. COLD AIR
TRAPPED IN SOME SKAMANIA COUNTY VALLEYS MAY ALSO LEAD TO SOME POCKETS
OF FREEZING RAIN THROUGH WED MORNING.
DECIDED TO ADD A SLIGHT CHANCE OF THUNDER FOR THE COAST AND COASTAL
WATERS LATER TONIGHT THROUGH WED EVENING AS THE 00Z NAM SUGGESTS
ENOUGH COLD AIR ALOFT TO DESTABILIZE THE ATMOSPHERE FOR A
THUNDERSTORM OR TWO. 04Z HRRR AND THE PREVIOUS COUPLE RUNS HAVE BEEN
SUGGESTING A BIT OF A CONVECTIVE LINE MAY DEVELOP WITH THE COLD FRONT
AS IT MOVES ONSHORE WED MORNING...ESPECIALLY FOR OUR SOUTHERN ZONES.
WE KEPT THUNDER CHANCES LIMITED TO THE COAST...BUT IT IS NOT OUT OF
THE QUESTION THAT A STRAY LIGHTNING STRIKE OR TWO MAKE IT EAST OF THE
COAST RANGE LATER TONIGHT AND WED. MADE VERY FEW CHANGES BEYOND WED
AND PREVIOUS DISCUSSION BELOW HANDLES THE NEXT SYSTEM WELL. WEAGLE
/FROM PREV DISCUSSION ISSUED 227 PM TUE JAN 12 2016/
SNOW LEVELS HAVE ALREADY RISEN ABOVE THE CASCADE PASSES EARLY THIS
AFTERNOON. THE KTTD PROFILER INDICATES SNOW LEVELS NEAR 6000 FEET.
GOVERNMENT CAMP WAS AROUND 35 DEG AND SANTIAM JCT...NEAR 4000
FEET...WAS AT 39 DEG. SNOW LEVELS FALL AGAIN WEDNESDAY AS THE UPPER
TROUGH MOVES INLAND. THERE IS SOME POTENTIAL FOR LOW-END SNOW
ADVISORY AMOUNTS IN THE CASCADES WED. GFS SHOWS ONE FINAL SHORT-WAVE
TROUGH MOVING ACROSS THU EVENING. THERE WILL BE A SHORT BREAK OR
DECREASE IN THE ACTION THU NIGHT AS THE NEXT DEVELOPING LOW TAKES
SHAPE IN THE ERN PAC. OFFSHORE LOW-LEVEL RETURNS LATE THU AND AND THU
EVENING. THIS WILL LIKELY DRIVE SNOW LEVELS LOWER THAN MODELS
SUGGEST...ESPECIALLY FOR THE S WA CASCADES...UPPER HOOD RIVER VALLEY
AND CENTRAL COLUMBIA GORGE. THIS SYSTEM MOVES INLAND LATE THU AND THU
NIGHT...WITH THE BRUNT OF IT HEADING INTO SW OREGON. SNOW LEVELS TO
REMAIN BELOW THE CASCADE PASSES WITH THIS SYSTEM WITH ADVISORY
AMOUNTS HIGHLY LIKELY. BELIEVE THE SYSTEM MOVES THROUGH TOO QUICKLY
FOR WARNING AMOUNTS. MODELS MAINTAIN SOME LINGERING PRECIP OVER MUCH
OF THE FORECAST AREA FRI MORNING DESPITE DEVELOPING 500 MB RIDGING.
THERE MAY BE A 6-12 HR DRY OR NEARLY-DRY PERIOD FRI AFTERNOON THROUGH
FRI EVENING BEFORE OVER-RUNNING FROM THE NEXT SYSTEM ARRIVES.
WEISHAAR
.LONG TERM...THE WET AND PROGRESSIVE PATTERN CONTINUES THROUGH THE
LONG TERM. GFS AND ECMWF SHOW ANOTHER SYSTEM MOVING THROUGH THE AREA
SAT. SNOW LEVELS SHOULD REMAIN AT OR JUST BELOW THE CASCADE PASSES
FOR ADDITIONAL ACCUMULATIONS. THIS SYSTEM DOES NOT LOOK QUITE AS WET
AS ITS PREDECESSORS BUT COULD STILL PRODUCE SNOW ADVISORY AMOUNTS FOR
THE CASCADES. MODELS SHOW MORE VARIANCE SUN WITH THE GFS SHOWING
ANOTHER SYSTEM. IT STAYS FAIRLY CONSOLIDATED. THE ECMWF HAS STRONGER
500 MB RIDGING OVER THE AREA WITH WARM-FRONTAL OVER-RUNNING SPREADING
ACROSS THE NRN ZONES SUN. MODELS MAINTAIN A FAIRLY PROGRESSIVE NATURE
EARLY NEXT WEEK WITH 1000-500 MB THICKNESS VALUES HOVERING AROUND 540
DM...OR CLOSE TO THE CASCADE PASSES. WEISHAAR
&&
.AVIATION...AN OCCLUDED FRONT WILL MAINTAIN RAIN AND VARIABLE
CLOUDS THROUGH WED MORNING...WITH A MIX OF FLIGHT CONDITIONS.
CONDITIONS WILL MOSTLY BE A MIX OF VFR AND MVFR...BUT BRIEF
PERIODS OF IFR CONDITIONS ARE POSSIBLE JUST ABOUT ANYWHERE. THE
RAIN WILL TURN TO SHOWERS WED AFTERNOON...AND CIGS SHOULD RISE.
EAST WINDS WILL CONTINUE TO GUSTS TO 35 KT NEAR THE GORGE THIS
EVENING....GRADUALLY DECREASING AFTER MIDNIGHT.
KPDX AND APPROACHES...MOSTLY VFR TONIGHT. CIGS WILL LIKELY LOWER
TO MVFR BY 15Z. VFR CONDITIONS WITH SHOWERS WED. E WINDS 20-25KT
TONIGHT...BECOMING S 15KT AROUND 15Z. TJ
&&
.MARINE...A LOW MOVING SOUTH TO NORTH ALONG AN OCCLUDED FRONT
BROUGHT A BURST OF SOUTHERLY GALES TO THE WATERS...AND STORM FORCE
WINDS SOUTH OF CASCADE HEAD THIS EVENING. THE WINDS WILL
DRAMATICALLY WEAKEN AROUND MIDNIGHT AS THE LOW MAKES
LANDFALL...AND WINDS WILL VEER TO THE NW. RATHER BENIGN WINDS WED
AS HIGH PRESSURE BRIEFLY RETURNS. THE THURSDAY FRONT LOOKS VERY
SIMILAR TO THE CURRENT ONE...AND MAY SEE ANOTHER COASTAL JET WITH
A BURST OF STRONG WINDS IN THE AFTERNOON OR EVENING. FORECAST
CONFIDENCE IN THE WINDS ARE HIGH ENOUGH TO ISSUE ANY WATCHES. A
COUPLE OF FRONTS WILL BRING CHANCES FOR GALES...OR POSSIBLY STORM
THURSDAY...AND FRI NIGHT THROUGH SAT.
WIND WAVES FROM THE STRONGER WINDS THIS EVENING HAS RAISED SEAS TO
18 FT SOUTH OF CASCADE HEAD...AND WILL RAPIDLY SUBSIDE TONIGHT.
SEAS WILL GENERALLY FLUCTUATE BETWEEN 10 AND 13 FT WED THROUGH THU
MORNING. WIND WAVES WILL THEN RISE WITH THE FRONT THU AFTERNOON
WITH SEAS BACK IN THE MID TO UPPER TEENS. LOWS MOVING ACROSS THE
PACIFIC LATE IN THE WEEK WILL PRODUCE LARGER SEAS THIS
WEEKEND...POSSIBLY EXCEEDING 20 FT.TJ
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 4 AM PST WEDNESDAY FOR UPPER HOOD
RIVER VALLEY.
WA...WINTER WEATHER ADVISORY UNTIL 2 PM PST WEDNESDAY FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 1 AM PST WEDNESDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM PST
THURSDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 AM
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 SIOUX FALLS SD
355 PM CST WED JAN 13 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 355 PM CST WED JAN 13 2016
PRIMARY CONCERNS TONIGHT WILL DEAL WITH THE POTENTIAL FOR FOG INTO
THURSDAY MORNING...AS WELL AS DEGREE OF TEMPERATURE WARMING ON
THURSDAY.
THIS AFTERNOON...SOUTHWESTERLY WINDS HAVE PUSHED TEMPERATURES INTO
THE 30S IN MOST AREAS. AREAS OF THE FAR SOUTHERN CWA ADJACENT
TO THE SAND HILLS WILL CLIMB INTO THE LOWER 40S.
TONIGHT...HIGH RESOLUTION GUIDANCE CONTINUES TO SUGGEST WINDS SHOULD
WEAKEN AS THE EVENING PROGRESSES ON...WITH A STATIONARY BOUNDARY
FORMING ALONG A HON TO FSD TO STORM LAKE LINE. WEAK CONVERGENCE
ALONG THIS BOUNDARY COMBINED WITH CONTINUED WARM ADVECTION OVERTOP
THE COLD SNOWPACK WOULD FAVOR FOG DEVELOPMENT ESPECIALLY SOUTH OF
THE BUFFALO RIDGE AFTER MIDNIGHT. WE WILL NEED TO WAIT FOR A BROAD
MID-LVL CLOUD DECK TO SLIDE EASTWARD...WHICH WILL ALLOW TEMPERATURES
TO DROP QUICKLY. ONCE TEMPERATURES BEGIN TO DROP...FOG COULD QUICKLY
BECOME DENSE ESPECIALLY ACROSS THE EASTERN HALF OF THE TRI-STATE
AREA. SREF PROBABILITIES SUGGEST RATHER HIGH PROBABILITIES OF
VISIBILITY LESS THAN 1 MILE...BUT THE COVERAGE OF THOSE VISIBILITIES
IS IN DOUBT.
ANOTHER WARM DAY IS EXPECTED ON THURSDAY...BUT POTENTIAL DOES EXIST
THAT FOG MAY FORM INTO A STRATUS DECK OVER THE NERN HALF OF THE CWA.
TEMPERATURES WILL AGAIN CLIMB INTO THE 30S BY THE AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 PM CST WED JAN 13 2016
THE INITIAL ARTIC PUSH LOOKS TO WORK INTO THE FORECAST AREA THURSDAY
EVENING. NOT MUCH IN THE WAY OF SYNOPTIC LIFT...BUT AS THE COOLER
AIR WORKS INTO THE REGION...COLD AIR COULD PRODUCE ENOUGH LIFT TO
PRODUCE A SMALL AMOUNT OF PRECIPITATION. DEEPER SATURATION APPEARS
TO BE ACROSS THER NORTHERN HALF OF THE FORECAST AREA AND HAVE
CONCENTRATED THE HIGHEST POPS THERE.
ATMOSPHERE DRIES OUT ON FRIDAY WITH NORTHWEST FLOW PREVAILING ACROSS
THE AREA. THE NORTHWEST FLOW WILL KEEP 925 HPA TEMPS AROUND -10C
FRIDAY INTO SATURDAY...WHEN A SEOCND PUSH OF ARCITIC AIR WORKS
SOUTH. AS WITH PREVIOUS FORECASTER...RAISED WINDS OVER INITIAL
GUIDANCE DURING THE PUSHES OF ARCTIC AIR TO ACCOUNT FOR MIXING AND
COLD AIR ADVECTION.
COLD AIR LOOKS TO REMAIN IN PLACE TILL EARLY NEXT WEEK. ECMWF IS
MORE AGGRESSIVE IN MOVING THE ARCTIC AIR EAST SUNDAY NIGHT INTO
MONDAY...WHILE THE GFS KEEPS IT AROUND FOR AT LEAST THE FIRST HALF
OF THE WEEK. STARTED TO TREND TEMPS WARMER ON DAYS 5 THROUGH
7...BUT DIDN/T MAKE MAJOR CHANGES COMPARED TO GUIDANCE AS
CLIMATOLOGICAL BIAS. GFS KEEPS ZONAL FLOW THROUGH MUCH OF NEXT
WEEK...WHILE THE ECMWF SUGGEST THE POTENTIAL FOR A MAJOR SOUTHERN
STREAM WAVE WORKING INTO THE CENTER PORTION OF THE COUNTRY LATE NEXT
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 939 AM CST WED JAN 13 2016
VFR CONDITIONS ARE EXPECTED TO PERSIST INTO THE EVENING HOURS. WE
WILL SEE AN INCREASE IN HIGH AND MID LVL CLOUDS THIS EVENING AS
INITIAL BAND OF WARM ADVECTION AHEAD OF AN UPPER WAVE MOVES
THROUGH.
HOWEVER...MODELS SUGGEST THIS CLOUD COVER SLIDES JUST NORTHEAST OF
THE AREA AFTER MIDNIGHT. WITH A WEAK SFC TROUGH FORMING NEAR OR
OVER THE CWA AND PERSISTENT WARM ADVECTION OVER THE SNOW
PACK...WOULD NOT BE SURPRISED TO SEE FOG AND EVEN DENSE FOG FORM
ALONG A LINE FROM HON TO FSD TO SLB...BUT ESPECIALLY ACROSS SW
MINNESOTA.
SREF HINTING AT HIGH PROBABILITIES OF VISIBILITIES LESS THAN 1
MILE...AND THIS IS ALSO SUPPORTED BY THE RAP AND HRRR. WILL
INTRODUCE FOG THROUGH THURSDAY MORNING...BUT WITH UNCERTAINTY WILL
KEEP VISIBILITIES AT HIGHER LEVELS AND LET FOLLOWING SHIFTS ADJUST
LOWER AS NEEDED.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...DUX
LONG TERM...
AVIATION...DUX
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1047 AM CST WED JAN 13 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CST WED JAN 13 2016
TEMPERATURES WILL BE THE PRIMARY FOCUS FOR THE NEXT 24 HOURS...AS
RELATIVELY BRIEF WARM SURGE CONTINUES TO BUILD INTO THE FORECAST
AREA AHEAD OF LATE WEEK CLIPPER. EARLY MORNING TEMPERATURES ALREADY
5-10 DEGREES WARMER THAN READINGS 24 HOURS AGO...AND THAT 24-HOUR
CHANGE WILL ONLY GROW AS WE PROGRESS THROUGH THE DAY...AS READINGS
CLIMB TOWARD HIGHS IN THE UPPER 20S AND 30S. WIDE VARIANCE BETWEEN
VERY MILD NUMERICAL MOS GUIDANCE AND MUCH COOLER RAW MODEL VALUES...
MAKING IT A TOUGH CALL ON JUST HOW WARM WE WILL GET WITH WIDESPREAD
SNOW COVER. EXPECT A FAIR AMOUNT OF SUNSHINE...AND WITH SNOWPACK NOW
GETTING TO BE ON THE OLDER SIDE FOR MOST...SHOULD SEE ABILITY FOR
DECENT WARMING. FOR NOW HEDGED JUST A LITTLE WARMER THAN PREVIOUS
FORECAST GIVEN RELATIVELY MILD START TO THE DAY AND 30S ALREADY ON
OUR DOORSTEP IN GREGORY COUNTY AND POINTS WEST/SOUTH.
WINDS FAIRLY LIGHT TONIGHT AS THEY BECOME A LITTLE MORE SOUTHERLY...
BUT INCREASE IN CLOUDS THIS EVENING SHOULD TEMPER ANY POTENTIAL FOR
A RAPID FALL AS THE WINDS DIMINISH. THUS EXPECT A MILD NIGHT WITH
LOWS IN THE UPPER TEENS TO MID 20S. WITH SOME AREAS WARMING ABOVE
FREEZING TODAY...AND LIGHT WINDS TONIGHT...GAVE SOME THOUGHT TO
POTENTIAL FOR PATCHY/SHALLOW FOG. SOME OF THE COOLER MODELS DO SHOW
THIS...HOWEVER CONFIDENCE IN THOSE MODELS GENERALLY LOW AS THEY HAVE
TO TENDENCY TO OVERDO LOW CLOUDS/FOG DEVELOPMENT. SO WITHOUT BROADER
MODEL CONSENSUS WILL NOT INCLUDE AT THIS TIME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 300 AM CST WED JAN 13 2016
THURSDAY STILL LOOKS MILD AS LOW PRESSURE MOVES FROM SOUTH CENTRAL
ND TO SOUTH CENTRAL MN THROUGH THE DAY. 925MB TEMPERATURES RANGE
FROM ABOUT -2C NEAR MARSHALL MN...TO +2C IN OUR FAR SOUTHWEST CORNER
AT GREGORY COUNTY ON BOTH THE GFS AND ECMWF. THEREFORE HIGHS RANGING
FROM THE UPPER 20S IN SOUTHWEST MN TO LOWER 40S IN GREGORY COUNTY
STILL LOOK VERY REASONABLE. THEN THURSDAY NIGHT...THE BOTTOM BEGINS
TO DROP OUT OF OUR TEMPERATURES AS THE FIRST COLD FRONT MOVES
SOUTHWARD. RELIED HEAVILY ON A BLEND OF BIAS CORRECTED AND ECMWF
VALUES WHICH WERE A BIT COOLER THEN CONVENTIONAL BLENDED VALUES. THE
MOISTURE DEPTH IS FAIRLY DEEP THURSDAY NIGHT WHICH SHOULD GIVE AREAS
OF LIGHT SNOW OR FLURRIES. BUT WITH TEMPERATURES SUBSTANTIALLY
WARMER AT 850MB WHEN COMPARED TO 925MB...INSTABILITY IS LACKING
REALLY ALL THE WAY THROUGH 600MB...SO NOT EXPECTING MUCH IN THE WAY
OF ACCUMULATING SNOW. FOR TEMPERATURES...LOWS ARE TRICKY THURSDAY
NIGHT BECAUSE TEMPERATURES WILL LIKELY CONTINUE TO FALL THROUGH
FRIDAY MORNING. FOR NOW...HAVE CLOSE TO 10 DEGREES FOR A LOW NEAR
HURON AND BROOKINGS...SLOWLY WARMING TO AROUND 20 NEAR SIOUX CITY.
ON FRIDAY...MOISTURE DEPTH BEGINS TO SHALLOW OUT SO CONDITIONS
SHOULD BE DRY. AS ELUDED TO ABOVE...TEMPERATURES WILL NOT RECOVER
MUCH AT ALL...PERHAPS JUST A CATEGORY OR TWO IN THE EARLY AND MID
AFTERNOON WHEN COLD AIR ADVECTION TEMPORARILY SUBSIDES. SIMILAR TO
THURSDAY...USED ECMWF AND BIAS CORRECTED VALUES FOR HIGHS. THE NEXT
COLD FRONT AND ACCOMPANYING SHORT WAVE DROPS SOUTHWARD FRIDAY
NIGHT...THIS TIME WITH ARCTIC ORIGINS. SIMILAR TO THURSDAY
NIGHT...THE MOISTURE DEPTH INCREASES ONCE AGAIN AND THIS TIME THE
PROFILE IS PRETTY DENDRITIC FROM THE SURFACE TO 600MB. THEREFORE
FAIRLY CERTAIN THAT FLURRIES WILL OCCUR FOR MOST LOCATIONS AND
INCLUDED THEM IN THE FORECAST. WITH STRONG COLD AIR ADVECTION IN
PLACE...INCREASED WINDS ABOVE SUPERBLEND VALUES GIVING WIND CHILL
VALUES WHICH COULD REACH ADVISORY CRITERIA ROUGHLY ALONG AND EAST OF
A BROOKINGS TO SPENCER IA LINE BY LATE FRIDAY NIGHT OF -20F OR
COLDER.
TEMPERATURES WILL HAVE A VERY SMALL RISE ON SATURDAY AND COUPLED
WITH WIND...THE SAME LOCATIONS MENTIONED ABOVE COULD SEE WIND CHILL
ADVISORY CONDITIONS LINGERING THROUGH THE DAY. THOUGHT ABOUT KEEPING
FLURRIES IN...BUT THE DAY PERIOD ON SATURDAY CURRENTLY HAS THE
MOISTURE DEPTH GETTING SHALLOW AGAIN AND WITH TEMPERATURES GETTING
SUBSTANTIALLY COLDER THEN DENDRITIC. SO WOULD NOT RULE OUT FLURRIES
ON SATURDAY...BUT THEY SHOULD BE PRETTY INSIGNIFICANT. SKIES SHOULD
CLEAR SATURDAY NIGHT ALLOWING TEMPERATURES TO PLUMMET. WITH THE WIND
IN PLACE...THE ENTIRE FORECAST AREA WILL VERY LIKELY SEE WIND CHILL
ADVISORY CONDITIONS WITH POSSIBLY EVEN WIND CHILL WARNING OF -35F
ALONG AND EAST OF A HURON TO SPENCER IA LINE BY LATE SATURDAY NIGHT
AND EARLY SUNDAY MORNING. FRIGID CONDITIONS WILL CONTINUE SUNDAY AND
SUNDAY NIGHT WITH A SLIGHT MODERATION BY MONDAY. HIGHS SHOULD
MODERATE FURTHER ON TUESDAY WITH HIGHS IN THE UPPER TEENS AND 20S
AS SURFACE WINDS BECOME SOUTHERLY AND A ZONAL UPPER FLOW IN PLACE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 939 AM CST WED JAN 13 2016
VFR CONDITIONS ARE EXPECTED TO PERSIST INTO THE EVENING HOURS. WE
WILL SEE AN INCREASE IN HIGH AND MID LVL CLOUDS THIS EVENING AS
INITIAL BAND OF WARM ADVECTION AHEAD OF AN UPPER WAVE MOVES
THROUGH.
HOWEVER...MODELS SUGGEST THIS CLOUD COVER SLIDES JUST NORTHEAST OF
THE AREA AFTER MIDNIGHT. WITH A WEAK SFC TROUGH FORMING NEAR OR
OVER THE CWA AND PERSISTENT WARM ADVECTION OVER THE SNOW
PACK...WOULD NOT BE SURPRISED TO SEE FOG AND EVEN DENSE FOG FORM
ALONG A LINE FROM HON TO FSD TO SLB...BUT ESPECIALLY ACROSS SW
MINNESOTA.
SREF HINTING AT HIGH PROBABILITIES OF VISIBILITIES LESS THAN 1
MILE...AND THIS IS ALSO SUPPORTED BY THE RAP AND HRRR. WILL
INTRODUCE FOG THROUGH THURSDAY MORNING...BUT WITH UNCERTAINTY WILL
KEEP VISIBILITIES AT HIGHER LEVELS AND LET FOLLOWING SHIFTS ADJUST
LOWER AS NEEDED.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JH
LONG TERM...MJ
AVIATION...DUX
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
247 PM EST WED JAN 13 2016
.SHORT TERM (TONIGHT AND TOMORROW)...
CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES
RATHER ZONAL FLOW ACROSS THE AREA. AT THE SURFACE...HIGH PRESSURES
IS BEGINNING TO SLIDE TO THE SOUTHEAST. WITH THE MOVEMENT OF THE
SURFACE HIGH...LOW LEVELS WINDS WILL TAKE ON MORE OF A
SOUTHWESTERLY DIRECTION THIS AFTERNOON AND TONIGHT WITH WARM AIR
ADVECTION MOVING INTO THE AREA. THERE IS A WEAK SHORTWAVE TROUGH
MOVING THROUGH THE MID-MISSISSIPPI RIVER VALLEY BUT WITH PW VALUES
SO LOW...DO NOT EXPECT ANYTHING MORE THAN A SLIGHT INCREASE IN
CLOUD COVER LATER THIS EVENING. LOW TEMPERATURES SHOULD BE A GOOD 5
TO 10 DEGREES WARMER THAN LAST NIGHT WITH A LIGHT SOUTHWEST WIND
KEEPING THE BOUNDARY LAYER MIXED AND THE WARM AIR ADVECTION. FOR
TOMORROW...TEMPERATURES AND DEWPOINTS WILL CONTINUE TO INCREASE
WITH LOW LEVEL WARM AIR AND MOISTURE ADVECTON. THE AMPLE SUPPLY ON
SUNSHINE SHOULD ALSO HELP TEMPERATURES TOP OUT IN THE 50S ACROSS
MOST OF THE AREA.
.LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...
MODELS SHOW LIMITED PHASING OF THE NORTHERN AND SOUTHERN STREAM
WAVES FOR FRIDAY...BUT ENOUGH FRONTAL-GENETIC LIFT TO PRODUCE
LIKELY CHANCES OF SHOWERS. SOME LIGHT SNOW SHOWERS/FLURRIES ON THE
BACK SIDE.
BIG DIFFERENCES BETWEEN THE GFS AND ECMWF MODELS FOR THIS WEEKEND.
GFS SUGGEST A GOOD SNOWFALL AREA-WIDE WHILE THE ECMWF KEEPS SOUTHERN
STREAM WAVE IN THE GULF. A WEAK NORTHERN STREAM WAVE DOES EFFECT THE
AREA SUNDAY BRINGING RETURN OF COLD TEMPERATURES AND LIGHT SNOW
SHOWERS/FLURRIES...BUT LIMITED SNOW ACCUMULATIONS.
WILL TREND TOWARD THE ECMWF SINCE ENSEMBLES ARE ALSO TRENDING DRIER
AND COLDER WITH MORE OF A NORTHERN STREAM INFLUENCE.
COLD AND DRY WEATHER FOR THE REST OF THE EXTENDED WITH A GRADUAL
WARMING TREND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 31 57 38 52 / 0 0 20 70
KNOXVILLE MCGHEE TYSON AIRPORT, TN 29 55 34 50 / 0 0 10 60
OAK RIDGE, TN 29 55 35 50 / 0 0 10 60
TRI CITIES AIRPORT, TN 24 52 28 49 / 0 0 0 60
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
MA/DH
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1059 PM CST TUE JAN 12 2016
.AVIATION...
ALTHOUGH THERE WAS A DIFFERENCE IN THE MODEL DATA...THE AREA MOST
CONDUCIVE FOR FOG FORMATION TONIGHT LOOKS TO BE OVER KCXO AND
KLBX. HOWEVER...THERE IS A POTENTIAL OVER MOST SITES FROM KCXO TO
JUST INLAND OF THE COAST. THE TIME PERIOD STILL LOOKS TO BE
BETWEEN 10Z AND 15Z. OTHERWISE...VFR CONDITIONS ARE EXPECTED.
40
&&
.PREV DISCUSSION... /ISSUED 818 PM CST TUE JAN 12 2016/
DISCUSSION...
CLEAR SKIES AND LIGHT WINDS COUPLED WITH A SUBTLE INCREASE IN LOW
LEVEL MOISTURE SHOULD ALLOW FOR SOME FOG FORMATION OVERNIGHT. THE
HRRR AND RAP ARE BOTH VERY AGGRESSIVE WITH FOG DEVELOPMENT OVER
THE SW ZONES LATER TONIGHT. THE SREF ENSEMBLES CONSIDERABLY LESS
BULLISH WITH FOG THREAT. 00Z SOUNDINGS FROM CRP AND LCH DON`T LOOK
TERRIBLY FAVORABLE EITHER BUT WILL ADD PATCHY FOG TO THE GRIDS
AND MENTION LOCALLY DENSE TO THE SW ZONES FOR LATE TONIGHT. IF
THE HRRR/RAP ARE CORRECT...A DENSE FOG ADVISORY MAY BE REQUIRED
LATER TONIGHT FOR AREAS SW OF HOUSTON. BUMPED MIN TEMPS UP A
DEGREE OR TWO IN A FEW SPOTS AND LOWER ALONG THE IMMEDIATE COAST.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 40 63 48 64 49 / 0 10 10 30 10
HOUSTON (IAH) 41 63 49 66 50 / 0 10 10 40 20
GALVESTON (GLS) 47 62 55 62 54 / 0 10 20 50 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1055 PM CST TUE JAN 12 2016
.AVIATION.../06 TAF CYCLE/
VFR CONDITIONS PREVAIL AND ARE EXPECTED TO PERSIST THROUGH THE
OVERNIGHT AND INTO WEDNESDAY. THE PREVIOUSLY LEANING HIGH-END
MVFR VISIBILITIES HAVE BEEN REMOVED FOR THIS CYCLE AS BUFR
SOUNDINGS HAVE BACKED OFF FROM LOW-LEVEL SATURATION. IT STILL
APPEARS THAT SOME SHALLOW GROUND FOG COULD DEVELOP ACROSS THE
COASTAL PLAINS AND IN RIVER VALLEYS. THIS COVERAGE SHOULD BE TOO
LIMITED TO AFFECT TAF SITES AND HAVE LEFT THEM CLEAR OVERNIGHT.
WINDS ARE LIGHT AND VARIABLE CURRENTLY AND WILL REMAIN SO
OVERNIGHT. WEAK 5-10 KT WINDS WILL RESUME BY LATE MORNING
WEDNESDAY ACROSS THE REGION FROM THE SOUTH.
&&
.PREV DISCUSSION... /ISSUED 930 PM CST TUE JAN 12 2016/
UPDATE...
A CLUSTER OF UPPER LEVEL CLOUDS AHEAD OF THE NEXT UPPER LEVEL
SYSTEM FORECAST TO AFFECT THE AREA WILL KEEP OVERNIGHT LOWS A BIT
WARMER THAN PREVIOUS NIGHTS. THESE UPPER LEVEL CLOUDS WILL REMAIN
ACROSS THE AREA ON WEDNESDAY WHILE LOW LEVEL MOISTURE INCREASES
AHEAD OF A PACIFIC FRONT. WEDNESDAYS HIGH TEMPERATURES ARE
EXPECTED TO REACH THE MID 60S OVER MOST LOCATIONS. RAIN CHANCES
ARE IN STORE FOR AREAS MAINLY ALONG AND EAST OF INTERSTATE 35 ON
THURSDAY AS THE UPPER LEVEL LOW AND PACIFIC FRONT PUSHES OVER THE
AREA. DRY WEATHER CONDITIONS ARE EXPECTED ON FRIDAY WITH RAIN
CHANCES RETURNING ON SATURDAY ACROSS THE EAST AS ANOTHER PACIFIC
FRONT PUSHES OVER THE AREA.
PREV DISCUSSION... /ISSUED 550 PM CST TUE JAN 12 2016/
AVIATION.../00Z TAF CYCLE/
SKC VFR PREVAILS OVER THE REGION WITH ONLY SOME HIGH SCT250 CIRRUS
POISED TO FILTER OVER THE REGION OVERNIGHT FROM THE SOUTHWEST.
WINDS ARE LIGHT AND VARIABLE AT 5 KT OR LESS AND WILL REMAIN SO
THROUGH 12Z. ONE ASPECT THAT WILL NEED TO BE WATCHED WITH BE
SHALLOW GROUND FOG AND/OR ISOLATED PATCHY IFR CIGS NEAR 12-15Z.
HAVE PLACED 5SM BR FOR NOW TO HEDGE THIS DIRECTION BUT BUFR
SOUNDINGS AND TIME-HEIGHTS OF THE HRRR INDICATE VERY LOW-LVL
SATURATION THAT COULD RESULT IN BRIEF LOWER RESTRICTIONS. WILL
MONITOR THESE TRENDS INTO THE 06Z TAF CYCLE. OTHERWISE...VFR IS
EXPECTED TO PREVAIL WEDNESDAY.
PREV DISCUSSION... /ISSUED 306 PM CST TUE JAN 12 2016/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
A GRADUAL INCREASE IN MOISTURE IS EXPECTED TONIGHT AND WEDNESDAY
AS SOUTHERLY FLOW IN THE LOW-LEVELS DEVELOPS. THE SOUTHERLY FLOW
SHOULD ALLOW FOR A LITTLE MILDER OVERNIGHT LOWS TONIGHT.
HOWEVER...CAN/T RULE OUT A FEW SPOTS DROPPING TO NEAR FREEZING
ACROSS THE WESTERN HILL COUNTRY. RAIN CHANCES RETURN TO THE RIO
GRANDE PLAINS SOUTH OF EAGLE PASS AND MOST OF THE COASTAL PLAINS
WEDNESDAY NIGHT AS AN UPPER TROUGH APPROACHES FROM THE WEST. ONLY
LIGHT AMOUNTS ARE EXPECTED AND WE/LL KEEP RAIN CHANCES IN THE
SLIGHT CHANCE CATEGORY (20%) FOR NOW AS DEEP LAYER MOISTURE AND
LIFT WILL BE LACKING.
LONG TERM (THURSDAY THROUGH TUESDAY)...
RAIN CHANCES CONTINUE ON THURSDAY FOR AREAS ALONG AND EAST OF I-35
AS THE ABOVE MENTIONED UPPER LEVEL TROUGH MOVES ACROSS SOUTHERN
TEXAS. WE/LL ALSO CONTINUE TO MENTION THE CHANCE FOR ISOLATED
THUNDERSTORMS EAST OF A TAYLOR TO FLORESVILLE LINE WITH SOME
MEAGER ELEVATED INSTABILITY MOVING IN WITH THE UPPER TROUGH. THE
UPPER TROUGH AXIS MOVES TO OUR EAST THURSDAY NIGHT...BRINGING AN
END TO RAIN CHANCES. A PACIFIC COLD FRONT WILL ALSO BEGIN TO MOVE
THROUGH THE REGION THURSDAY NIGHT BRINGING MUCH DRIER AIR TO SOUTH
CENTRAL TEXAS. DRY WEATHER IS ANTICIPATED FOR ALL AREAS ON FRIDAY
BEFORE ANOTHER COLD FRONT MOVES THROUGH SATURDAY AFTERNOON. THE
COLD FRONT ON SATURDAY WILL ALSO BE ACCOMPANIED BY A FAIRLY
COMPACT AND FAST MOVING UPPER TROUGH. THIS WILL LIKELY LEAD TO
WINDY CONDITIONS ACROSS THE REGION ON SATURDAY. MOISTURE RETURN
AHEAD OF THIS FRONT WILL BE LACKING AND FOR NOW... WE/LL ONLY
MENTION A SLIGHT CHANCE FOR SHOWERS EAST OF A GEORGETOWN TO KARNES
CITY LINE. THE MEDIUM RANGE MODELS CONTINUE TO SHOW SOME
DISAGREEMENT WITH THE WEATHER PATTERN EARLY NEXT WEEK. IT DOES
APPEAR THAT WE/LL BE A LITTLE DRIER THAN PREVIOUS MODELS INDICATED
AS MOISTURE RETURN AHEAD OF THE NEXT COLD FRONT WILL BE LACKING.
WE/LL KEEP A LOW CHANCE FOR SHOWERS EAST OF I-35 AND GO WITH A DRY
FORECAST ELSEWHERE.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 41 64 47 65 47 / 0 0 10 20 10
AUSTIN BERGSTROM INTL AIRPORT 36 63 44 65 45 / 0 0 20 20 10
NEW BRAUNFELS MUNI AIRPORT 38 63 46 66 45 / 0 0 20 20 10
BURNET MUNI AIRPORT 38 63 43 64 44 / 0 0 - 10 -
DEL RIO INTL AIRPORT 40 63 44 67 43 / 0 0 - 0 0
GEORGETOWN MUNI AIRPORT 37 63 44 65 46 / 0 0 - 20 10
HONDO MUNI AIRPORT 38 63 45 66 43 / 0 0 10 10 0
SAN MARCOS MUNI AIRPORT 38 63 45 65 46 / 0 0 20 20 10
LA GRANGE - FAYETTE REGIONAL 40 64 48 66 50 / 0 0 20 40 10
SAN ANTONIO INTL AIRPORT 40 63 47 65 47 / 0 0 20 20 -
STINSON MUNI AIRPORT 41 63 48 65 46 / 0 0 20 20 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...ALLEN
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
230 AM CST FRI JAN 15 2016
.SHORT TERM...(Today)
ISSUED AT 229 AM CST FRI JAN 15 2016
Latest surface analysis had low pressure centered over southwest
Wisconsin, with the trailing cold front extending southwest into the
southern Plains. The low is forecast to reach eastern Michigan by
this evening, with the cold front expected to be east of the forecast
area by mid-afternoon. The front is strong temperature-wise, and
temperatures will be falling in its wake. This will result in high
temperatures being reached early this morning across west-central
Illinois, with temperatures likely falling for the rest of the day.
The biggest question with respect the front is if it will provide
precipitation across central and southeast Illinois. The airmass the
front is moving into is quite dry per 00Z ILX and forecast
soundings. This is also shown by the significant lack of cloud cover
showing up in local surface observations (clouds below 12K feet).
The only nearby rainfall at the moment is a thin line of showers
along the front in Missouri. Model guidance continues to suggest
that the rainfall will expand within the pre-frontal WAA/isentropic
lift. However, there is not much time for moistening to occur before
FROPA across at least the western portion of the forecast area.
Still expect at least a few hour period of rain across the eastern
portion of the forecast area, mainly before noon, but significant
rainfall is not anticipated. Forecast soundings suggest the
precipitation will cut off before temperatures are cold enough for
snow.
&&
.LONG TERM...(Tonight through Thursday)
ISSUED AT 229 AM CST FRI JAN 15 2016
Next lobe of Arctic air poised to start its southward push,
associated with a large upper low currently just north of Lake
Winnipeg. More recent model runs are a bit slower in getting the
core of the cold air mass this far south, with the strongest surge
taking place Sunday as 850 mb temps drop to around -21C. Thus, made
some adjustments with the temperatures for Saturday night and Sunday
by bringing them up a few degrees, which will lessen the risk of
needing a wind chill advisory as early as Saturday night. Sunday
night still looking to be the coldest, with wind chills of -15F as
far south as I-70 and many areas seeing lows below zero.
In regards to the weekend snow threat, with the upper low itself a
bit delayed in arriving, have backed off some with the snow chances
late Saturday night and mainly limited them northwest of the
Illinois River. Main threat will be Sunday morning, but the window
of opportunity appears to be shrinking as most of the models
diminish the amount of precip accumulation as the wave passes
through. Thus, left PoP`s generally in the 30% range for now, with
some slight chances lingering across the southeast half of the CWA
into afternoon.
Longer range remains a bit challenging as the Arctic air mass exits.
The latest ECMWF now suggests mainly a Tuesday night-Wednesday
morning event with the wave that will be dropping out of the
Dakotas, while the GFS a more pronounced and longer-lasting system
due to a more prominent upper trough extending south into Texas.
This results in that model featuring a broad trough and cooler air
persisting into mid week, while the ECMWF quickly warms ahead of the
late week system. Model performance this far out has not been
consistent as of late, leading to lower confidence for the forecast
details beyond Wednesday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1148 PM CST THU JAN 14 2016
Relatively dry air in place across central IL will slow down the
development of MVFR cloud conditions and light rain later tonight.
The low levels will see the increasing moisture primarily, with
deep layer moisture developing toward 15z and mainly east of I-55,
ahead of an approaching cold front. Still seeing an overall delay
in the start of rain, but spotty showers or drizzle could begin as
early as 10z-12z. Profiles never become saturated through a deep
layer, even in the east, so contemplated keeping only a mention
VCSH with the front. However, decided to go with the actual precip
type to outline the progression of when rain will change to snow,
if precip does occur.
The HRRR and NAM/GFS soundings still point toward a period of IFR
clouds during the FROPA hours. Will continue to include IFR cloud
heights at all terminal sites for the mid morning to late
afternoon time frame. Once the boundary pushes east, gusty
southerly winds will veer to the west Friday morning, then NW
and increasing to 15-20kt Fri afternoon and evening. FROPA timing
appears to be about 16z at KPIA and closer to 18z at KCMI. While
sustained surface winds will remain quite brisk at around 12-20kt
tonight, radar VWP plots and the NAM are showing a strong 45-50kt
925mb jet ongoing. Have therefore continued to include low-level
wind shear at the TAF sites the rest of tonight.
As for precip type, decided to introduce light snow in the
afternoon, transitioning first near PIA by 18z, then advancing
eastward to CMI and DEC by late afternoon. Snow accumulation
potential is low, due to limited moisture after the change over to
snow occurs.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...BAK
LONG TERM...Geelhart
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1148 PM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 900 PM CST THU JAN 14 2016
The 00z KILX sounding indicated very dry air in place across
central Illinois this evening. Even an upstream 00z sounding at
KSGF, Springfield Missouri, showed similarly dry conditions. The
HRRR and RAP models have been progressively slowing down the onset
of any precipitation across central Illinois, as have the NAM12
and namdng but to a lesser extent. Satellite loops are showing the
upstream shortwave in eastern Texas and Arkansas may take a track
that would focus our forcing for precip later tonight and Friday
to areas east of I-55. The passage of the cold front in
conjunction with the arrival of upper level energy will put the
better chances of rain mainly from mid morning into early
afternoon, before the front departs into Indiana.
Have updated the PoP and weather grids to slow down the onset of
rain overnight, with only slight chances of precip before 12z.
Also reduced the areal coverage of likely PoPs Friday morning
closer to the I-57 corridor and areas east of there.
The arrival of colder air will be late enough in the event to
limit the potential of accumulating snowfall, and mainly north of
I-74.
Temperatures overnight will likely remain much above normal under
the continued mild southwest flow. A few strong wind gusts could
continue to show up as well, with a 50kt LLJ just above the
ground, and marginal decoupling of the boundary layer this
evening.
Updated forecast info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 322 PM CST THU JAN 14 2016
20z/2pm surface analysis shows 1022mb high anchored over Georgia,
while a 997mb low organizes over eastern South Dakota. The pressure
gradient between these two features will continue to provide a
warm/southerly flow across central Illinois tonight, which will keep
temperatures several degrees warmer than in previous nights. Thanks
to southerly winds of 10 to 15mph through the night and increasing
clouds, overnight low temperatures will remain in the upper 30s and
lower 40s. As the South Dakota low tracks eastward into Wisconsin,
it will pull a cold front toward the region later tonight.
Increasing low-level moisture along/ahead of the boundary will
eventually yield a few light rain showers after midnight. HRRR
suggests the precip will develop along/west of a Champaign to
Taylorville line between 06z and 09z...then will spread further
eastward across the remainder of the area toward dawn. Since
forecast soundings do not fully saturate through a deep layer...will
maintain just chance PoPs overnight until deeper moisture arrives
Friday morning.
.LONG TERM...(Friday through Thursday)
ISSUED AT 322 PM CST THU JAN 14 2016
Models in good agreement with the system that will be moving through
the CWA Friday, as the low pressure area moves across the Great
Lakes with the trailing cold front sliding across the state during
the morning. Once this occurs, much colder air will pour into the
area with temperatures falling during the afternoon hours. During
the day, all the pcpn will be liquid, but when the temps begin to
fall the pcpn will become mixed with snow as it is ending. Do not
see any accumulation of snowfall with this system. Then, after a
brief period of dry weather thru Saturday evening, a clipper system
will move toward the area and bring snow to the area beginning late
Sat night and continuing through Sunday morning. By Sun afternoon,
the snow will have ended and moved east of the area.
Temps will be warm one more day, tomorrow, but then fall beginning
in the afternoon. So, look for morning or late morning highs. Temps
will continue to fall during the night, and then go back up on Sat,
but remain below normal. Then much colder air will pour into the
area for the weekend, with temps below zero in the north Sat night.
Below zero temps are expected again Sun night, but over most of the
area...with only southeast IL seeing above zero temps...though in
the single digits.
Next chance of pcpn will be another clipper system coming toward the
area, but tracking mostly south of the CWA for Tue into Tue night.
Will have a chance of snow in the southwest third of the area for
Tue and then a slight chance of snow over the whole area for Tue
night. Then toward the later half of the week, another weather
system will move toward the area. Models show much disagreement with
this system at this point, so will just go with the blend for now
and have a slight chance of pcpn for Wed night and then a chance
across the southern half of the CWA for Thur. P-type will be mainly
snow in the north, but a mix of rain and snow in the south.
Temps will start cold, but gradually warm back toward normal for Wed
and Thur.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1148 PM CST THU JAN 14 2016
Relatively dry air in place across central IL will slow down the
development of MVFR cloud conditions and light rain later tonight.
The low levels will see the increasing moisture primarily, with
deep layer moisture developing toward 15z and mainly east of I-55,
ahead of an approaching cold front. Still seeing an overall delay
in the start of rain, but spotty showers or drizzle could begin as
early as 10z-12z. Profiles never become saturated through a deep
layer, even in the east, so contemplated keeping only a mention
VCSH with the front. However, decided to go with the actual precip
type to outline the progression of when rain will change to snow,
if precip does occur.
The HRRR and NAM/GFS soundings still point toward a period of IFR
clouds during the FROPA hours. Will continue to include IFR cloud
heights at all terminal sites for the mid morning to late
afternoon time frame. Once the boundary pushes east, gusty
southerly winds will veer to the west Friday morning, then NW
and increasing to 15-20kt Fri afternoon and evening. FROPA timing
appears to be about 16z at KPIA and closer to 18z at KCMI. While
sustained surface winds will remain quite brisk at around 12-20kt
tonight, radar VWP plots and the NAM are showing a strong 45-50kt
925mb jet ongoing. Have therefore continued to include low-level
wind shear at the TAF sites the rest of tonight.
As for precip type, decided to introduce light snow in the
afternoon, transitioning first near PIA by 18z, then advancing
eastward to CMI and DEC by late afternoon. Snow accumulation
potential is low, due to limited moisture after the change over to
snow occurs.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
330 AM EST FRI JAN 15 2016
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 245 PM EST THU JAN 14 2016
A COLD FRONT WILL BRING RAIN TO CENTRAL INDIANA FRIDAY...THEN AN
ARCTIC COLD FRONT WILL BRING SOME SNOW ON SUNDAY ALONG WITH MUCH
COLDER AIR. THE FRIGID AIR WILL LAST UNTIL MID WEEK BEFORE
TEMPERATURES MODERATE SOME. SOME LIGHT SNOW IS POSSIBLE TUESDAY
NIGHT AND AGAIN THURSDAY.
&&
.NEAR TERM /OVERNIGHT|/...
ISSUED AT 933 PM EST THU JAN 14 2016
LOW PRESSURE CENTERED OVER IOWA WAS HELPING TO PROVIDE A WARM AND
SOUTHERLY FLOW OF AIR TO CENTRAL INDIANA AS DEW POINTS HAVE SOARED
INTO THE 30S AND TEMPS WERE HOLDING IN THE 40S. SATELLITE SHOWS
SOME MID AND HIGH CLOUD ACROSS TENNESSEE AND KENTUCKY STREAMING
NORTH TOWARD INDIANA.
GFS 290K SURFACE REVEALS GOOD ISENTROPIC LIFT EXPECTED BY 12Z AS A
SURGE OF MOISTURE ARRIVES WITH SPECIFIC HUMIDITIES OVER 5 G/KG.
TIME HEIGHTS AND FORECAST SOUNDINGS ALSO SHOWING GOOD LOWER LEVEL
SATURATION BY 12Z. HRRR SHOWS PRECIP BREAKING OUT TOWARD 12Z
WITHIN THE ISENTROPIC LIFT. BETTER FORCING WILL ARRIVE AFTER 12Z
AS THE SHORT WAVE OVER THE WESTERN PLAINS ARRIVES IN CENTRAL
INDIANA. THUS WILL CONTINUE THE ONGOING FORECAST OVERNIGHT...WITH
INCREASING CLOUDS AND MAINLY A DRY NIGHT...BUT INCHING POPS UPWARD
AFTER 09Z.
AS FOR TEMPS...HAVE RAISED TEMPS ABOUT 2-3 DEGREES DUE TO EXPECTED
INCREASING CLOUDS ALONG WITH ONGOING WARM AIR ADVECTION.
&&
.SHORT TERM.../FRIDAY THROUGH SUNDAY/
ISSUED AT 245 PM EST THU JAN 14 2016
FOCUS IS ON PRECIPITATION CHANCES EARLY AND LATE IN THE PERIOD.
OVERALL...MODELS ARE SIMILAR WITH THE BIG PICTURE. THERE ARE SOME
TIMING DIFFERENCES WITH THE ARCTIC FRONT SATURDAY NIGHT/SUNDAY
MORNING. THAT FAR OUT...DECIDED A BLEND WOULD STILL WORK OUT BEST
GIVEN THE UNCERTAINTY INVOLVED.
ON FRIDAY AN UPPER TROUGH AND COLD FRONT WILL MOVE INTO THE AREA.
850MB WINDS NEAR 50KT...ISENTROPIC LIFT...AND LARGER SCALE DYNAMICS
FROM THE TROUGH WILL WORK TOGETHER TO PRODUCE RAIN ACROSS THE AREA.
WENT LIKELY OR CATEGORICAL POPS ALL AREAS.
RAIN WILL DIMINISH ACROSS THE WEST DURING THE AFTERNOON BEHIND THE
FRONT...AND TEMPERATURES MAY COOL ENOUGH THERE FOR SOME SNOW TO MIX
IN WITH ANY LINGERING RAIN BY LATE FRIDAY AFTERNOON.
UPPER TROUGH AXIS WILL STILL BE CROSSING THE AREA FRIDAY EVENING AND
CYCLONIC FLOW WILL CONTINUE THROUGH THE NIGHT. THIS SHOULD BE ENOUGH
FOR MAINLY SOME SLIGHT CHANCE POPS THROUGH THE PERIOD. TEMPERATURES
WILL BE COLD ENOUGH FOR SNOW AS THE PRECIPITATION TYPE.
ON SATURDAY THE BULK OF THE MOISTURE WILL MOVE OUT OF THE
AREA...REDUCING THE CHANCES FOR SNOW. CANNOT RULE OUT SOME FLURRIES
/OR PERHAPS FREEZING DRIZZLE IF ENOUGH MOISTURE EXITS ALOFT/. WILL
PUT SOME FLURRIES IN FOR NOW.
ARCTIC FRONT APPROACHES SATURDAY NIGHT AND MOVES THROUGH ON SUNDAY.
WENT WITH SOME SLIGHT CHANCE POPS FAR NORTHWEST LATE IN THE NIGHT TO
ACCOUNT FOR THE POTENTIAL OF THE FRONT REACHING THERE BY 12Z.
EXPECT TYPICAL CONDITIONS TO OCCUR ON SUNDAY WHEN AN ARCTIC FRONT
MOVES THROUGH...SO WENT SCATTERED SNOW SHOWERS ALL AREAS. NAM
INDICATES SNOW SQUALL POTENTIAL IN SOME AREAS...AND MODEL TIME
SECTIONS SHOW PERHAPS SOME WEAK INSTABILITY. THUS SOME OF THE SNOW
SHOWERS COULD BE BRIEFLY HEAVY. HOWEVER OVERALL ACCUMULATION LOOKS
TO BE LESS THAN AN INCH.
GENERALLY STAYED WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE
SHORT TERM.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 255 AM EST FRI JAN 15 2016
A DRY AND BITTER COLD START WILL OCCUR DURING THE LONG TERM AS A COLD
UPPER LOW MOVES EAST ACROSS THE GREAT LAKES. MODELS INDICATE 850 MB
TEMPERATURES NEAR -20 CELSIUS AND SURFACE TEMPERATURES APPROACHING ZERO
ON MONDAY.
HIGH PRESSURE WILL MOVE EAST ACROSS OUR REGION TUESDAY. THE UPPER FLOW
WILL BECOME MORE ZONAL DURING THE 2ND HALF OF THE LONG TERM. HOWEVER A
COUPLE OF SYSTEMS IN THE SOUTHERN STREAM WILL BRING LOW CHANCES OF SNOW
LATE TUESDAY NIGHT INTO WEDNESDAY FOLLOWED BY ANOTHER SYSTEM BRINGING
CHANCE POPS AGAIN WEDNESDAY NIGHT AND THURSDAY. MODEL LOW LEVEL THICKNESS
INDICATE MIXED PRECIPITATION MAY OCCUR OVER SOUTHERN SECTIONS BY THURSDAY...
WHILE MOST OTHER AREAS REMAIN FROZEN.
MADE A FEW TWEAKS TO LOWER MIN TEMPERATURES SLIGHTLY TUESDAY MORNING AND RAISED
MINS SLIGHTLY WEDNESDAY MORNING AND THURSDAY. OTHERWISE...MODEL INITIALIZATION
TEMPERATURES SEEM REASONABLE.
&&
.AVIATION /DISCUSSION FOR THE 150900Z KIND TAF UPDATE/...
ISSUED AT 330 AM EST FRI JAN 15 2016
MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.
PREVIOUS AVIATION DISCUSSION FOLLOWS...
STRENGTHENING LOW LEVEL SOUTH SOUTHWESTERLY FLOW TONIGHT SHOULD ALLOW FOR
CEILINGS 040-050 CURRENTLY OVER THE LOWER MISSISSIPPI VALLEY TO ADVECT
OVER THE TERMINALS BY 150900Z. THE SUSTAINED WARM/MOIST ADVECTION PATTERN
MAY ALLOW FOR CEILINGS TO FALL INTO THE MVFR CATEGORY TOWARDS/AFTER SUNRISE
ON FRIDAY...AND EVENTUALLY INTO THE IFR CATEGORY BY 151800Z.
ORGANIZED LIFT FROM APPROACHING SYSTEM WILL BEGIN MOVING INTO THE AREA
BY THE LATE MORNING HOURS ON FRIDAY...SO SHOULD SEE AREAS OF RAIN STARTING
TO IMPACT THE TERMINALS FROM THE SOUTHWEST AFTER THAT TIME.
SOME CONCERN FOR LOW LEVEL WIND SHEAR OVERNIGHT AROUND 015 AS A
40-45KT LOW LEVEL JET MOVES THROUGH. AT THIS TIME...IT APPEARS WIND SHEAR
WILL REMAIN JUST BELOW CRITERIA. THREAT FOR LOW LEVEL WIND SHEAR SHOULD
DIMINISH AFTER SUNRISE AS LOW LEVEL JET SHIFTS EAST AND WEAKENS.
SURFACE WINDS GENERALLY 180-200 DEGREES AT 10-13 KTS THROUGH MIDDAY FRIDAY.
MAY BE SOME LOCALIZED SURFACE GUSTS 20-25 KTS OVERNIGHT AS THE LOW LEVEL
JET MAY TEMPORARILY BREAK THE INVERSION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM...JH
AVIATION...JAS/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
255 AM EST FRI JAN 15 2016
.UPDATE...
LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 245 PM EST THU JAN 14 2016
A COLD FRONT WILL BRING RAIN TO CENTRAL INDIANA FRIDAY...THEN AN
ARCTIC COLD FRONT WILL BRING SOME SNOW ON SUNDAY ALONG WITH MUCH
COLDER AIR. THE FRIGID AIR WILL LAST UNTIL MID WEEK BEFORE
TEMPERATURES MODERATE SOME. SOME LIGHT SNOW IS POSSIBLE TUESDAY
NIGHT AND AGAIN THURSDAY.
&&
.NEAR TERM /OVERNIGHT|/...
ISSUED AT 933 PM EST THU JAN 14 2016
LOW PRESSURE CENTERED OVER IOWA WAS HELPING TO PROVIDE A WARM AND
SOUTHERLY FLOW OF AIR TO CENTRAL INDIANA AS DEW POINTS HAVE SOARED
INTO THE 30S AND TEMPS WERE HOLDING IN THE 40S. SATELLITE SHOWS
SOME MID AND HIGH CLOUD ACROSS TENNESSEE AND KENTUCKY STREAMING
NORTH TOWARD INDIANA.
GFS 290K SURFACE REVEALS GOOD ISENTROPIC LIFT EXPECTED BY 12Z AS A
SURGE OF MOISTURE ARRIVES WITH SPECIFIC HUMIDITIES OVER 5 G/KG.
TIME HEIGHTS AND FORECAST SOUNDINGS ALSO SHOWING GOOD LOWER LEVEL
SATURATION BY 12Z. HRRR SHOWS PRECIP BREAKING OUT TOWARD 12Z
WITHIN THE ISENTROPIC LIFT. BETTER FORCING WILL ARRIVE AFTER 12Z
AS THE SHORT WAVE OVER THE WESTERN PLAINS ARRIVES IN CENTRAL
INDIANA. THUS WILL CONTINUE THE ONGOING FORECAST OVERNIGHT...WITH
INCREASING CLOUDS AND MAINLY A DRY NIGHT...BUT INCHING POPS UPWARD
AFTER 09Z.
AS FOR TEMPS...HAVE RAISED TEMPS ABOUT 2-3 DEGREES DUE TO EXPECTED
INCREASING CLOUDS ALONG WITH ONGOING WARM AIR ADVECTION.
&&
.SHORT TERM.../FRIDAY THROUGH SUNDAY/
ISSUED AT 245 PM EST THU JAN 14 2016
FOCUS IS ON PRECIPITATION CHANCES EARLY AND LATE IN THE PERIOD.
OVERALL...MODELS ARE SIMILAR WITH THE BIG PICTURE. THERE ARE SOME
TIMING DIFFERENCES WITH THE ARCTIC FRONT SATURDAY NIGHT/SUNDAY
MORNING. THAT FAR OUT...DECIDED A BLEND WOULD STILL WORK OUT BEST
GIVEN THE UNCERTAINTY INVOLVED.
ON FRIDAY AN UPPER TROUGH AND COLD FRONT WILL MOVE INTO THE AREA.
850MB WINDS NEAR 50KT...ISENTROPIC LIFT...AND LARGER SCALE DYNAMICS
FROM THE TROUGH WILL WORK TOGETHER TO PRODUCE RAIN ACROSS THE AREA.
WENT LIKELY OR CATEGORICAL POPS ALL AREAS.
RAIN WILL DIMINISH ACROSS THE WEST DURING THE AFTERNOON BEHIND THE
FRONT...AND TEMPERATURES MAY COOL ENOUGH THERE FOR SOME SNOW TO MIX
IN WITH ANY LINGERING RAIN BY LATE FRIDAY AFTERNOON.
UPPER TROUGH AXIS WILL STILL BE CROSSING THE AREA FRIDAY EVENING AND
CYCLONIC FLOW WILL CONTINUE THROUGH THE NIGHT. THIS SHOULD BE ENOUGH
FOR MAINLY SOME SLIGHT CHANCE POPS THROUGH THE PERIOD. TEMPERATURES
WILL BE COLD ENOUGH FOR SNOW AS THE PRECIPITATION TYPE.
ON SATURDAY THE BULK OF THE MOISTURE WILL MOVE OUT OF THE
AREA...REDUCING THE CHANCES FOR SNOW. CANNOT RULE OUT SOME FLURRIES
/OR PERHAPS FREEZING DRIZZLE IF ENOUGH MOISTURE EXITS ALOFT/. WILL
PUT SOME FLURRIES IN FOR NOW.
ARCTIC FRONT APPROACHES SATURDAY NIGHT AND MOVES THROUGH ON SUNDAY.
WENT WITH SOME SLIGHT CHANCE POPS FAR NORTHWEST LATE IN THE NIGHT TO
ACCOUNT FOR THE POTENTIAL OF THE FRONT REACHING THERE BY 12Z.
EXPECT TYPICAL CONDITIONS TO OCCUR ON SUNDAY WHEN AN ARCTIC FRONT
MOVES THROUGH...SO WENT SCATTERED SNOW SHOWERS ALL AREAS. NAM
INDICATES SNOW SQUALL POTENTIAL IN SOME AREAS...AND MODEL TIME
SECTIONS SHOW PERHAPS SOME WEAK INSTABILITY. THUS SOME OF THE SNOW
SHOWERS COULD BE BRIEFLY HEAVY. HOWEVER OVERALL ACCUMULATION LOOKS
TO BE LESS THAN AN INCH.
GENERALLY STAYED WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE
SHORT TERM.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 255 AM EST FRI JAN 15 2016
A DRY AND BITTER COLD START WILL OCCUR DURING THE LONG TERM AS A COLD
UPPER LOW MOVES EAST ACROSS THE GREAT LAKES. MODELS INDICATE 850 MB
TEMPERATURES NEAR -20 CELSIUS AND SURFACE TEMPERATURES APPROACHING ZERO
ON MONDAY.
HIGH PRESSURE WILL MOVE EAST ACROSS OUR REGION TUESDAY. THE UPPER FLOW
WILL BECOME MORE ZONAL DURING THE 2ND HALF OF THE LONG TERM. HOWEVER A
COUPLE OF SYSTEMS IN THE SOUTHERN STREAM WILL BRING LOW CHANCES OF SNOW
LATE TUESDAY NIGHT INTO WEDNESDAY FOLLOWED BY ANOTHER SYSTEM BRINGING
CHANCE POPS AGAIN WEDNESDAY NIGHT AND THURSDAY. MODEL LOW LEVEL THICKNESS
INDICATE MIXED PRECIPITATION MAY OCCUR OVER SOUTHERN SECTIONS BY THURSDAY...
WHILE MOST OTHER AREAS REMAIN FROZEN.
MADE A FEW TWEAKS TO LOWER MIN TEMPERATURES SLIGHTLY TUESDAY MORNING AND RAISED
MINS SLIGHTLY WEDNESDAY MORNING AND THURSDAY. OTHERWISE...MODEL INITIALIZATION
TEMPERATURES SEEM REASONABLE.
&&
.AVIATION /DISCUSSION FOR THE 150600Z TAFS/...
ISSUED AT 1136 PM EST THU JAN 14 2016
STRENGTHENING LOW LEVEL SOUTH SOUTHWESTERLY FLOW TONIGHT SHOULD ALLOW FOR
CEILINGS 040-050 CURRENTLY OVER THE LOWER MISSISSIPPI VALLEY TO ADVECT
OVER THE TERMINALS BY 150900Z. THE SUSTAINED WARM/MOIST ADVECTION PATTERN
MAY ALLOW FOR CEILINGS TO FALL INTO THE MVFR CATEGORY TOWARDS/AFTER SUNRISE
ON FRIDAY...AND EVENTUALLY INTO THE IFR CATEGORY BY 151800Z.
ORGANIZED LIFT FROM APPROACHING SYSTEM WILL BEGIN MOVING INTO THE AREA
BY THE LATE MORNING HOURS ON FRIDAY...SO SHOULD SEE AREAS OF RAIN STARTING
TO IMPACT THE TERMINALS FROM THE SOUTHWEST AFTER THAT TIME.
SOME CONCERN FOR LOW LEVEL WIND SHEAR OVERNIGHT AROUND 015 AS A
40-45KT LOW LEVEL JET MOVES THROUGH. AT THIS TIME...IT APPEARS WIND SHEAR
WILL REMAIN JUST BELOW CRITERIA. THREAT FOR LOW LEVEL WIND SHEAR SHOULD
DIMINISH AFTER SUNRISE AS LOW LEVEL JET SHIFTS EAST AND WEAKENS.
SURFACE WINDS GENERALLY 180-200 DEGREES AT 10-13 KTS THROUGH MIDDAY FRIDAY.
MAY BE SOME LOCALIZED SURFACE GUSTS 20-25 KTS OVERNIGHT AS THE LOW LEVEL
JET MAY TEMPORARILY BREAK THE INVERSION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM...JH
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1136 PM EST THU JAN 14 2016
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 245 PM EST THU JAN 14 2016
A COLD FRONT WILL BRING RAIN TO CENTRAL INDIANA FRIDAY...THEN AN
ARCTIC COLD FRONT WILL BRING SOME SNOW ON SUNDAY ALONG WITH MUCH
COLDER AIR. THE FRIGID AIR WILL LAST UNTIL MID WEEK BEFORE
TEMPERATURES MODERATE SOME. SOME LIGHT SNOW IS POSSIBLE TUESDAY
NIGHT AND AGAIN THURSDAY.
&&
.NEAR TERM /OVERNIGHT|/...
ISSUED AT 933 PM EST THU JAN 14 2016
LOW PRESSURE CENTERED OVER IOWA WAS HELPING TO PROVIDE A WARM AND
SOUTHERLY FLOW OF AIR TO CENTRAL INDIANA AS DEW POINTS HAVE SOARED
INTO THE 30S AND TEMPS WERE HOLDING IN THE 40S. SATELLITE SHOWS
SOME MID AND HIGH CLOUD ACROSS TENNESSEE AND KENTUCKY STREAMING
NORTH TOWARD INDIANA.
GFS 290K SURFACE REVEALS GOOD ISENTROPIC LIFT EXPECTED BY 12Z AS A
SURGE OF MOISTURE ARRIVES WITH SPECIFIC HUMIDITIES OVER 5 G/KG.
TIME HEIGHTS AND FORECAST SOUNDINGS ALSO SHOWING GOOD LOWER LEVEL
SATURATION BY 12Z. HRRR SHOWS PRECIP BREAKING OUT TOWARD 12Z
WITHIN THE ISENTROPIC LIFT. BETTER FORCING WILL ARRIVE AFTER 12Z
AS THE SHORT WAVE OVER THE WESTERN PLAINS ARRIVES IN CENTRAL
INDIANA. THUS WILL CONTINUE THE ONGOING FORECAST OVERNIGHT...WITH
INCREASING CLOUDS AND MAINLY A DRY NIGHT...BUT INCHING POPS UPWARD
AFTER 09Z.
AS FOR TEMPS...HAVE RAISED TEMPS ABOUT 2-3 DEGREES DUE TO EXPECTED
INCREASING CLOUDS ALONG WITH ONGOING WARM AIR ADVECTION.
&&
.SHORT TERM.../FRIDAY THROUGH SUNDAY/
ISSUED AT 245 PM EST THU JAN 14 2016
FOCUS IS ON PRECIPITATION CHANCES EARLY AND LATE IN THE PERIOD.
OVERALL...MODELS ARE SIMILAR WITH THE BIG PICTURE. THERE ARE SOME
TIMING DIFFERENCES WITH THE ARCTIC FRONT SATURDAY NIGHT/SUNDAY
MORNING. THAT FAR OUT...DECIDED A BLEND WOULD STILL WORK OUT BEST
GIVEN THE UNCERTAINTY INVOLVED.
ON FRIDAY AN UPPER TROUGH AND COLD FRONT WILL MOVE INTO THE AREA.
850MB WINDS NEAR 50KT...ISENTROPIC LIFT...AND LARGER SCALE DYNAMICS
FROM THE TROUGH WILL WORK TOGETHER TO PRODUCE RAIN ACROSS THE AREA.
WENT LIKELY OR CATEGORICAL POPS ALL AREAS.
RAIN WILL DIMINISH ACROSS THE WEST DURING THE AFTERNOON BEHIND THE
FRONT...AND TEMPERATURES MAY COOL ENOUGH THERE FOR SOME SNOW TO MIX
IN WITH ANY LINGERING RAIN BY LATE FRIDAY AFTERNOON.
UPPER TROUGH AXIS WILL STILL BE CROSSING THE AREA FRIDAY EVENING AND
CYCLONIC FLOW WILL CONTINUE THROUGH THE NIGHT. THIS SHOULD BE ENOUGH
FOR MAINLY SOME SLIGHT CHANCE POPS THROUGH THE PERIOD. TEMPERATURES
WILL BE COLD ENOUGH FOR SNOW AS THE PRECIPITATION TYPE.
ON SATURDAY THE BULK OF THE MOISTURE WILL MOVE OUT OF THE
AREA...REDUCING THE CHANCES FOR SNOW. CANNOT RULE OUT SOME FLURRIES
/OR PERHAPS FREEZING DRIZZLE IF ENOUGH MOISTURE EXITS ALOFT/. WILL
PUT SOME FLURRIES IN FOR NOW.
ARCTIC FRONT APPROACHES SATURDAY NIGHT AND MOVES THROUGH ON SUNDAY.
WENT WITH SOME SLIGHT CHANCE POPS FAR NORTHWEST LATE IN THE NIGHT TO
ACCOUNT FOR THE POTENTIAL OF THE FRONT REACHING THERE BY 12Z.
EXPECT TYPICAL CONDITIONS TO OCCUR ON SUNDAY WHEN AN ARCTIC FRONT
MOVES THROUGH...SO WENT SCATTERED SNOW SHOWERS ALL AREAS. NAM
INDICATES SNOW SQUALL POTENTIAL IN SOME AREAS...AND MODEL TIME
SECTIONS SHOW PERHAPS SOME WEAK INSTABILITY. THUS SOME OF THE SNOW
SHOWERS COULD BE BRIEFLY HEAVY. HOWEVER OVERALL ACCUMULATION LOOKS
TO BE LESS THAN AN INCH.
GENERALLY STAYED WITH A MODEL BLEND FOR TEMPERATURES THROUGH THE
SHORT TERM.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 235 PM EST THU JAN 14 2016
VERY COLD START TO THE LONG TERM PERIOD EXPECTED...WITH LOWS IN THE
SINGLE DIGITS OR COLDER EARLY IN THE WEEK AND HIGHS ONLY IN THE LOW
TO MID TEENS MONDAY. TEMPERATURES SHOULD MODERATE THROUGH THE
REMAINDER OF THE WEEK WITH THE FREEZING MARK POTENTIALLY MAKING IT
BACK TO INDY BY THURSDAY.
REMOVED SOME SLIGHT CHANCE POPS IN PERIODS WHEN NEITHER THE GFS OR
EURO PRODUCED ANY QPF AND UPPER LEVEL SUPPORT WAS MINIMAL OR
NONEXISTENT. BLENDED INITIALIZATION TENDS TO OVERDO LOW POPS SO THIS
IS NOT SURPRISING.
MAY SEE A FEW FLAKES TUESDAY NIGHT AND PERHAPS THURSDAY AS ANOTHER
SYSTEM APPROACHES THE AREA. TEMPERATURES WILL BE MORE BORDERLINE
LATE IN THE WEEK AND SOME MIXED PRECIPITATION CANNOT BE RULED OUT.
&&
.AVIATION /DISCUSSION FOR THE 150600Z TAFS/...
ISSUED AT 1136 PM EST THU JAN 14 2016
STRENGTHENING LOW LEVEL SOUTH SOUTHWESTERLY FLOW TONIGHT SHOULD ALLOW FOR
CEILINGS 040-050 CURRENTLY OVER THE LOWER MISSISSIPPI VALLEY TO ADVECT
OVER THE TERMINALS BY 150900Z. THE SUSTAINED WARM/MOIST ADVECTION PATTERN
MAY ALLOW FOR CEILINGS TO FALL INTO THE MVFR CATEGORY TOWARDS/AFTER SUNRISE
ON FRIDAY...AND EVENTUALLY INTO THE IFR CATEGORY BY 151800Z.
ORGANIZED LIFT FROM APPROACHING SYSTEM WILL BEGIN MOVING INTO THE AREA
BY THE LATE MORNING HOURS ON FRIDAY...SO SHOULD SEE AREAS OF RAIN STARTING
TO IMPACT THE TERMINALS FROM THE SOUTHWEST AFTER THAT TIME.
SOME CONCERN FOR LOW LEVEL WIND SHEAR OVERNIGHT AROUND 015 AS A
40-45KT LOW LEVEL JET MOVES THROUGH. AT THIS TIME...IT APPEARS WIND SHEAR
WILL REMAIN JUST BELOW CRITERIA. THREAT FOR LOW LEVEL WIND SHEAR SHOULD
DIMINISH AFTER SUNRISE AS LOW LEVEL JET SHIFTS EAST AND WEAKENS.
SURFACE WINDS GENERALLY 180-200 DEGREES AT 10-13 KTS THROUGH MIDDAY FRIDAY.
MAY BE SOME LOCALIZED SURFACE GUSTS 20-25 KTS OVERNIGHT AS THE LOW LEVEL
JET MAY TEMPORARILY BREAK THE INVERSION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM...NIELD
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
306 AM EST FRI JAN 15 2016
.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 306 AM EST FRI JAN 15 2016
SURFACE LOW CENTER HAS REACHED SRN WISCONSIN EARLY THIS MORNING...
WITH THE ASSOCIATED WARM FRONT EXTENDING EASTWARD FROM THE LOW
CENTER THRU SRN LWR MICHIGAN. MODELS CONTINUE TO OVER-FORECAST
PRECIP ALONG AND NORTH OF THIS WARM FRONT. LATEST LOOK AT KAPX SHOWS
ONLY PATCHY LIGHT FREEZING DRIZZLE AND/OR FLURRIES LINGERING ACROSS
MANLY THE NRN HALF OF OUR CWA IN THE WAKE OF AN AREA OF LIGHT SNOW
THAT HAS PUSHED NORTH OF OUR CWA. A VERY LIGHT MIST/FREEZING DRIZZLE
IS FALLING HERE AT THE GAYLORD OFFICE...WHICH MAKES SENSE LOOKING AT
OUR MODEL SOUNDINGS FOR EARLY THIS MORNING. LOW LEVELS ARE SATURATED
THRU ABOUT 850 MB...WITH A THICK LAYER OF DRY AIR AT MID LEVELS...
AND THEN ADDITIONAL MOISTURE ABOVE 600 MB. LOW LEVEL MOISTURE COMES
NOWHERE NEAR THE -10 C ISOTHERM AND SURFACE TEMPS REMAIN WELL BELOW
FREEZING AT THIS HOUR...THUS THE PATCHY LIGHT FREEZING DRIZZLE.
BOTH THE LATEST RAP13 AND THE HRRR SHOW ONLY SMALL CHANCES OF LIGHT
PRECIP EARLY THIS MORNING ACROSS MOST OF OUR CWA THRU DAYBREAK...
WITH SOME INDICATION OF GRADUALLY INCREASING POPS AS WE HEAD THRU
THE DAY IN RESPONSE TO INCREASING LIFT AND MOISTURE NEAR THE SURFACE
LOW CENTER. HIGHEST POPS ACTUALLY DEVELOP ACROSS THE SE HALF OF OUR
CWA THIS AFTERNOON JUST AHEAD OF THE SURFACE LOW CENTER AS IT TRACKS
NE THRU NRN LWR MICHIGAN. MODEL SOUNDINGS STILL SUGGEST A RATHER
TIGHT LOW LEVEL THERMAL GRADIENT WILL SET UP ACROSS OUR SRN CWA
TODAY AS THE LOW TRACKS RIGHT OVERHEAD. BASED ON MODEL SOUNDINGS...
PRECIP SHOULD REMAIN ALL SNOW ACROSS ERN UPR MICHIGAN AND THE TIP OF
THE MITT...WITH A MIX OF RAIN/SNOW AND POSSIBLY SOME FREEZING RAIN
AND SLEET MIXING IN AT TIMES ALONG THE TIGHT TEMP GRADIENT. PRECIP
WILL LIKELY BECOME ALL RAIN FOR PORTIONS OF OUR SRN CWA AND
ESPECIALLY OUR SE CWA FROM ROGERS CITY TO HOUGHTON LAKE EASTWARD AS
THE WARMEST AIR SURGES NORTHWARD IN THE AFTERNOON WITHIN THIS AREA
JUST AHEAD OF THE SURFACE LOW CENTER. WITH HIGH TEMPS WARMING INTO
THE MID TO UPPER 30S ACROSS MOST OF NRN LWR MICHIGAN...DO NOT EXPECT
ANY SIGNIFICANT ICE ACCUMULATION...BUT WILL CERTAINLY KEEP A CLOSE
EYE ON PRECIP TYPE AND DURATION AS THIS EVENT UNFOLDS. PRIMARY
CHANGES TO THE FORECAST WILL BE TO DECREASE POPS...ESPECIALLY THIS
MORNING BASED ON NEAR TERM OBSERVED AND MODEL TRENDS. CAA KICKS IN
IN THE WAKE OF THE DEPARTING LOW TONIGHT...SWITCHING PRECIP TYPE
BACK OVER TO ALL SNOW. ALSO...OVER-LAKE INSTABILITY WILL AGAIN
INCREASE WITH ONGOING CAA...TARGETING NW FLOW AREAS FOR HIGHEST POPS
TONIGHT. NEW SNOW ACCUMULATIONS WILL BE A GENERAL 1 TO 3 INCHES
TODAY FOR OUR NRN CWA...WITH ANOTHER INCH OR SO TONIGHT.
&&
.SHORT TERM...(SATURDAY THROUGH SUNDAY NIGHT)
ISSUED AT 306 AM EST FRI JAN 15 2016
SATURDAY AND SUNDAY...COLD AND SNOWY WEATHER TO CONTINUE ACROSS THE
GREAT LAKES REGION THIS WEEKEND. A STORM SYSTEM OVER THE EASTERN
LAKES SATURDAY WILL EXIT NORTHEAST INTO QUEBEC SUNDAY...WHILE AN
UPPER LVL SYSTEM SETTLES INTO THE REGION. MODEL SOUNDINGS AND MSTR
PROGS SHOW MID LVL DRYING (700/500MB RH UNDER 50 PCT) SATURDAY
AFTERNOON AS THE SFC LOW LIFTS NORTHEAST INTO QUEBEC...DIMINISHING
SNOWFALL ACROSS NORTHEAST LOWER SATURDAY AFTERNOON AND EVENING.
HOWEVER LAKE EFFECT PARAMETERS WILL STRENGTHEN SATURDAY AFTERNOON
ACRS THE WRN LAKES...WITH 850MB TEMPS FALLING TO -16C WHILE LOW LVL
INVERSION HEIGHTS INCREASE TO 4K FEET. SFC-850MB WINDS WILL
TRANSITION FROM NORTHWEST TO WEST THROUGH SATURDAY AFTERNOON IN
DIMINISHING CYCLONIC FLOW ON THE BACKSIDE OF THE EXITING STORM
SYSTEM. OVERALL WILL DIMINISH POPS ACROSS NORTHEAST LOWER SATURDAY
MORNING AS DRY MID LVL AIR SETTLES OVER THE REGION...WITH AT LEAST
LIKELY POPS OVER THE WRN LAKES THROUGH SATURDAY EVENING DUE TO LAKE
EFFECTS
SIGNIFICANT SNOW IS POSSIBLE SUNDAY FOR PORTIONS OF NRN MI...THE
COMBINATION OF AN UPPER LOW DROPPING INTO THE GREAT LAKES AS MID LVL
MSTR INCREASES AND LAKE EFFECT PARAMETERS STRENGTHEN. 700/500MB RH
INCREASES TO GREATER THAN 90 PCT SUNDAY WHILE 850/500MB QVECTOR
CONVERGENCE SHOWS STRONG FORCING OVER NRN MI IN ADVANCE OF
APPROACHING UPPER LOW. MODEL SOUNDINGS CONTINUE TO SHOW LAKE
PARAMETERS IMPROVING THROUGH THE DAY SUNDAY AS 850MB TEMPS DROP TO
-24C...INVERSION HEIGHTS INCREASE TO NEARLY 9KT WITH ABUNDANCE MSTR
THROUGH THE COLUMN. LAKES BANDS WILL BE HIGHLY UNORGANIZED THROUGH
18Z SUNDAY AS SFC-850MB WINDS SHIFT FROM SOUTHWEST TO WEST BEFORE
FINALLY LOCKING IN NORTHWEST SUNDAY EVENING INTO MONDAY. OVERALL
WILL MENTION SNOW FOR THE ENTIRE CWA SUNDAY WITH LAKE ENHANCEMENTS
FORCING HIGHEST POPS OVER THE WRN LAKES.
HIGH TEMPERATURES THIS WEEKEND WILL FALL FROM NEAR SEASONAL READINGS
IN THE 20S SATURDAY TO BETWEEN 10 AND 15 DEGREES SUNDAY AS 850MB
TEMPS PLUNGE TO -24C IN DEEPENING UPPER TROUGH.
&&
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 306 AM EST FRI JAN 15 2016
MONDAY THROUGH THURSDAY...SURFACE AND UPPER LVL STORM SYSTEMS WILL
BE IN PLACE OVER THE GREAT LAKES TO BEGIN THE UPCOMING WORK
WEEK...BEFORE SLOWLY EXITING EAST OF THE REGION TUESDAY. THIS
PATTERN WILL GENERATE SNOW ACROSS MUCH OF NORTHERN MICHIGAN MONDAY
WITH LAKE EFFECT SNOW OVER THE WRN LAKES TUESDAY...DUE TO LINGERING
CYCLONIC FLOW ON THE BACK SIDE OF THE EXITING STORM SYSTEM (NW WINDS
SFC-850MB WITH INVERSION HEIGHTS TO 6K FT). TEMPERATURES WILL BE
BELOW NORMAL THROUGH TUESDAY AS 850MB TEMPS IN THE BASE OF THE 500MB
TROUGH DROP TO -24C...FORCING DAYTIME HIGHS TO REMAIN IN THE TEENS
WITH LOWS IN THE SINGLE DIGITS.
WEDNESDAY AND THURSDAY ARE CURRENTLY TRENDING LESS ACTIVE WHEN
COMPARED TO THE PAST WEEK. A LARGE AREA OF HIGH PRESSURE AND DRY AIR
WILL SETTLE OVER THE ENTIRE GREAT LAKES AND OHIO VALLEY BY MID
WEEK...WHILE 500MB HEIGHTS INCREASE ACROSS THE UPPER MIDWEST. ANY
LAKE INFLUENCES WEDNESDAY AND THURSDAY WILL BE HINDERED BY LACK OF
OVER WATER INSTABILITY WITH 850MB TEMPS WARMING TO -8C THURSDAY. THE
WARMING IN MID LVLS WILL HELP DAYTIME TEMPS TREND CLOSER TO MID
JANUARY SEASONAL LEVELS IN THE LOWER 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1154 PM EST THU JAN 14 2016
LOW PRESSURE WILL MOVE ACROSS NORTHERN MICHIGAN TODAY AND INTO
LAKE HURON LATER TONIGHT. THIS TRACK WILL BRING MILDER AIR UP
FROM THE SOUTH. ANY LIGHT SNOW WILL MIX WITH AND CHANGE OVER TO
RAIN...POSSIBLY EVEN A PERIOD OF FREEZING RAIN BEFORE
TRANSITIONING BACK OVER TO SNOW LATE FRIDAY...WITH AREAS OF
FREEZING DRIZZLE AND DRIZZLE MIXED IN EARLY THIS MORNING. CIGS
WILL BE DROPPING THROUGH MVFR TO IFR OVERNIGHT AND LIFR FOR A TIME
TODAY BEFORE LIKELY REBOUNDING BACK TO IFR THIS EVENING.
&&
.MARINE...
ISSUED AT 306 AM EST FRI JAN 15 2016
WINDS AND WAVES WILL REMAIN JUST AT SCA CRITERIA THRU MUCH OF TODAY
FOR OUR NRN NEARSHORE AREAS JUST NORTH OF THE SURFACE LOW CENTER
TRACK. MAINLY SNOW IS EXPECTED WITHIN THESE AREAS...WITH A WINTRY
MIX OF PRECIP EXPECTED FOR OUR NEARSHORE AREAS SOUTH OF THE ADVISORY
AREAS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
LHZ345>348.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR LMZ341-
342.
LS...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR LSZ321-
322.
&&
$$
NEAR TERM...MLR
SHORT TERM...SWR
LONG TERM...SWR
AVIATION...SULLIVAN
MARINE...MLR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1217 AM EST FRI JAN 15 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 258 PM EST THU JAN 14 2016
ONE LOW PRESSURE SYSTEM IN IOWA WILL TRACK EAST TONIGHT AND
THROUGH MICHIGAN ON FRIDAY. THIS SYSTEM COULD PRODUCE SOME LIGHT
RAIN. A COLDER AIRMASS RETURNS TO THE REGION FRIDAY NIGHT INTO
SATURDAY WITH LAKE EFFECT SNOW SHOWERS POSSIBLE NEAR THE
LAKESHORE. A REINFORCING SHOT OF ARCTIC AIR ARRIVES SUNDAY WITH
ACCUMULATING LAKE EFFECT SNOW LIKELY.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 258 PM EST THU JAN 14 2016
GIVEN THE CLEARING SKIES AND WARM AIR ADVECTION I DOWNPLAYED THE
POTENTIAL FOR SLEET AND FREEZING RAIN TONIGHT. STILL THE NORTHEAST
COUNTIES WILL BE CLOSE TO THE WARM FRONT AND A SMALL RISK EXISTS
UP THERE. TOO LOW FOR ANY HEADLINE AT THIS POINT. THE HRRR RUC WAS
SHOWING FOG TRYING TO DEVELOP LATER TONIGHT. I ADDED THIS TO THE
FORECAST.
A BETTER RISK FOR MEASURABLE RAIN EXISTS FOR FRIDAY. THE WAVE OF
LOW PRESSURE TRACKS EASTWARD THROUGH THE CWA. ENOUGH FORCING AND
MOISTURE AROUND FOR LIGHT RAIN. AT THIS POINT IT APPEARS THAT MOST
LOCATIONS WILL SEE LESS THAN A QUARTER INCH.
COLDER AIR RETURNS QUICKLY BEHIND THE DEPARTING LOW. THUS FRIDAY
NIGHT LOOKS LIKE MAINLY SNOW...IF ANY PRECIPITATION AT ALL. I AM
NOT CONFIDENT THAT WE WILL SEE MUCH PRECIPITATION AS THIS INITIAL
COLDER AIRMASS BEHIND THE LOW IS NOT THAT COLD...850 MB TEMPS DOWN
TO -8 DEG C OR SO. A BETTER SURGE OF ARCTIC AIR MOVES IN FOR LATER
SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 258 PM EST THU JAN 14 2016
WE STILL EXPECT A FEW INCHES OF LAKE EFFECT SNOW ON SUNDAY AND INTO
MONDAY. THE BULK OF THIS WILL FALL ON SUNDAY WITH A GENERAL 3 TO 5
INCHES ACROSS THE WESTERN ZONES. SNOW SHOWERS SHOULD REACH FAR
INLAND AS THE FLOW WILL BE FROM ABOUT 280 DEGREES WITH SOME ENHANCED
LOW LEVEL CONVERGENCE POSSIBLE ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA.
SUNDAY ALSO LOOKS MIGHTY COLD WITH 850 MB TEMPS BLO MINUS 20C AND
STRONG CAA ALL DAY. CORE OF THE COLDEST AIR COMES THROUGH DURING THE
AFTERNOON AND EVENING SO MAX TEMPS MIGHT OCCUR SUNDAY MORNING WITH
STEADY FOR FALLING TEMPERATURES DURING THE DAY AND WIND CHILLS
POSSIBLY GETTING DOWN TO 10 BELOW DURING THE EVENING.
MONDAY WILL SEE LAKE EFFECT SNOW SHOWERS CONTINUE WITH CYCLONIC FLOW
BUT ACCUMS ARE LIMITED BY INVERSION HEIGHTS AOB 5 KFT AND THE DGZ
NEAR THE SFC...SO ONLY ANOTHER INCH OR TWO EXPECTED.
THERE WILL BE A SLOW MODERATION IN TEMPERATURES FROM TUESDAY THROUGH
THURSDAY. IT REMAINS COLD ENOUGH FOR OCCASIONAL LAKE EFFECT SNOW
SHOWERS...ALTHOUGH AMOUNTS ARE EXPECTED TO BE LIGHT AS INVERSION
HEIGHTS REMAIN AOB 5 KFT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1215 AM EST FRI JAN 15 2016
AREAS OF MVFR FOG TONIGHT... WITH MVFR CIGS DEVELOPING FRIDAY
MORNING FOLLOWED BY WIDESPREAD IFR TO LIFR CIGS IN THE AFTERNOON
WHEN RAIN AND DRIZZLE BECOME MORE WIDESPREAD. LLWS THROUGH 12Z
FRIDAY WITH SOUTHWEST WINDS OF 40 KTS AT 2000 FT AND SFC WINDS
AROUND 10 KTS FROM THE SOUTHEAST.
&&
.MARINE...
ISSUED AT 258 PM EST THU JAN 14 2016
SOUTH TO SOUTHEAST WINDS WILL INCREASE TONIGHT. THIS WILL CAUSE
WAVES TO BUILD CLOSE TO SMALL CRAFT ADVISORY CRITERIA. THE WINDS
WILL VEER TO THE NORTHWEST BY FRIDAY NIGHT. AS COLDER AIR WORKS IT
WAY IN THE WAVES WILL BUILD TO OVER 4 FEET. HAZARDOUS CONDITIONS
FOR SMALL CRAFT WILL PERSIST THROUGH THE WEEKEND.
&&
.HYDROLOGY...
ISSUED AT 108 PM EST THU JAN 14 2016
ICE JAMMING IS LIKELY AFFECTING THE GRAND RIVER AT ROBINSON
TOWNSHIP. WARMER TEMPERATURES ALONG WITH SOME RAINFALL FRIDAY MAY
HELP LOOSEN THE JAM AND SOFTEN THE ICE FURTHER. THE FLOATING ICE
ON THE RIVER DOES NOT LOOK PARTICULARLY THICK SO IT MAY NOT TAKE
MUCH TO FREE THE JAM UP WITH MORE FAVORABLE WEATHER CONDITIONS
THROUGH FRIDAY. ELSEWHERE THERE IS LIKELY SOME ICE BUILDING
UPSTREAM OF DIMONDALE ON THE GRAND RIVER. HOWEVER...THE RIVER
STAGE AT DIMONDALE IS WELL BELOW BANKFULL PRESENTLY. WE WILL
CONTINUE TO MONITOR AREA RIVERS. A DEEP FREEZE LATER THIS WEEKEND
INTO NEXT WEEK WILL PUT A STOP TO ICE MOVEMENT AND WILL ALLOW FOR
ICE TO REDEVELOP. IF THE ROBINSON TWP JAM DOES NOT RELEASE BY THE
TIME THE ARCTIC AIR ARRIVES THEN MORE SIGNIFICANT ISSUES MAY
DEVELOP POTENTIALLY...WITH FURTHER ICE FORMATION OCCURRING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...OSTUNO
AVIATION...MEADE
HYDROLOGY...HOVING
MARINE...MJS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1056 PM CST THU JAN 14 2016
.UPDATE:
Issued at 847 PM CST Thu Jan 14 2016
Am in the process of updating the forecast for the rest of the
night and into Friday morning. RAP and HRRR have been backing off
precip for the overnight hours with each successive run. Seeing
some 5-7000 ft ceiling developing over eastern KS and western MO,
but no echos on radar yet. It looks like the RAP is hinting that
the warm advection showers ahead of the front will not be as wide
spread as the moisture convergence/warm advection does not appear
to be as strong as previously forecast. The bulk of the precip now
looks to be associated with the actual low level convergence ahead
of the front and energy aloft with the shortwave. Will be backing
off the areal coverage and moving timing later in the night for
the initial showers, and then bringing likely pops up the I-44
corridor from about 11Z to 15-16Z ahead of the front.
Carney
&&
.SHORT TERM: (Tonight through Friday)
Issued at 330 PM CST Thu Jan 14 2016
Still looking at a quick and light rain event for the area tonight
into Friday morning. Not much has changed except the models are a
tad slower with the trends and onset of precipitation with this
system. The short wave now moving into the Plains will amplify as
it moves into the MS Valley tonight and then exit rather quickly
into the OH Valley on Friday afternoon. Moisture is initially a
bit limited this evening, however low level WAA, large scale
forcing for ascent, and moisture will ramp up overnight and this
should lead to increasing coverage of showers with time, beginning
in southwest MO around mid-evening and spreading/developing into
the CWA after midnight. The precipitation should shut down by
early afternoon across the CWA as the short wave and associated
cold front move east. After the mild day today, it will feel
vastly different on Friday, especially in the afternoon with gusty
west-northwest winds contributing to strong CAA and falling
temperatures in the wake of the front.
Glass
.LONG TERM: (Friday Night through Next Thursday)
Issued at 330 PM CST Thu Jan 14 2016
Surface high pressure builds into the area Friday night into
Saturday and conditions are seasonably cold and relatively calm. A
strong upper vortex/trof will dig from east of Lake Winnipeg on
Saturday through the Great Lakes region Saturday and Saturday
night, carving out a long wave trof over the eastern 2/3rds of
the CONUS which will dominate Sunday-Monday. The height falls and
large scale ascent accompanying the upper system and frontogenesis
with a strong secondary cold surge will contribute to a region of
light snow. The best threat at this time will be centered along
and north of I-70 and a 1-2 inch event is possible. POPs are
probably too low but we con`t to increase them with sucessive
forecasts. Strong high pressure builds into the area Sunday
night into Monday as a very cold air mass, the coldest so far this
winter, settles in and brings a winter grip.
The flow aloft flattens after Monday in the wake of the departing
long wave trof in the east and considerable model variability
ensues in the deterministic and ensemble solutions. The ECMWF has
come around to the GFS with another light snow event centered on
Tuesday, however the system is much weaker. Another precipitation
event appears on tap on Thursday however there are large
differences in many details, especially the thermal structure.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1036 PM CST Thu Jan 14 2016
An upper level disturbance and cold front will move through our
area late tonight and Friday morning. MVFR cigs will develop and
spread northeastward into the taf sites late tonight, eventually
dropping into the IFR catagory, at least briefly early Friday
morning. A band of light rain will also move into the area late
tonight from southwest MO, mainly impacting the St Louis metro
area Friday morning. A strong swly low level jet will contribute
to LLWS conditions late tonight with swly winds at 1500-2000 feet
in height of 45-50 kts. The rain should shift east of the St Lous
metro area by late morning. Swly surface wind will veer around to
a nwly direction after fropa Friday morning. Post frontal MVFR
cigs will likely continue through the end of the forecast period.
Specifics for KSTL: Light rain along with MVFR cigs will spread
into STL around 12Z Friday. The ceiling will continue to drop
into the IFR catagory Friday morning. The rain should end by late
Friday morning, with the ceiling lifting back up into the MVFR
catagory by early afternoon. S-swly surface wind will veer around
to a nwly direction Friday morning after fropa, and strengthen
becoming gusty in the afternoon. The nwly surface wind will weaken
Friday night.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1141 PM CST THU JAN 14 2016
.UPDATE...
ISSUED AT 1141 PM CST THU JAN 14 2016
TWEAKED POPS A BIT FOR A FEW SPOTS STILL SEEING LINGERING SNOW IN
THE FAR SOUTHEASTERN COUNTIES...BUT OTHERWISE OUR SNOWFALL IS
WRAPPING UP. A FEW SITES SEEING LOWERED VIS AS WINDS KICK UP
SNOW...BUT NOTHING LESS THAN 2 MILES. CLEARING SKIES CONTINUE TO
SPREAD SOUTH BUT SOME CLOUDS ARE STARTING TO MOVE BACK IN JUST
WEST OF DEVILS LAKE.
UPDATE ISSUED AT 926 PM CST THU JAN 14 2016
VIS HAS COME UP TO 4SM AT PKD AND OVER 2SM AT DTL...AND THERE
SEEMS TO BE A WEAKENING TREND...SO WENT AHEAD AND LET THE HEADLINE
EXPIRE AT 03Z. THE WINDS HAVE BEEN PICKING UP A BIT FROM THE NORTH
BEHIND THE BAND...WITH SOME DRIFTING SNOW AND EVEN VIS REDUCTIONS
TO 1SM AT KFAR. THINK IT WILL BE SHORT LIVED SO JUST INSERTED A
MENTION IN THE EXPIRATION STATEMENT BUT WILL MONITOR IN CASE THE
WINDS LAST A BIT LONGER THAN EXPECTED. SFC HIGH PRESSURE HAS BEEN
BUILDING INTO THE NORTHERN CWA AND THERE HAS BEEN QUITE A BIT OF
CLEARING ACROSS THE NORTH. ADJUSTED CLOUD COVER FOR THIS CLEARING
AREA MOVING SOUTH THROUGHOUT THE NIGHT. THINK THAT CLOUDS WILL
MOVE BACK INTO THE NORTH LATE BUT NOT BEFORE TEMPS BOTTOM OUT NEAR
-10 IN THAT AREA. CURRENT READINGS HAVE A GOOD START.
UPDATE ISSUED AT 709 PM CST THU JAN 14 2016
ADJUSTED THE HEADLINE A BIT...AS SNOW CONTINUES OVER THE
SOUTHEASTERN COUNTIES IN THE ADVISORY. RADAR RETURNS ARE GOING
DOWN BUT PARTLY BECAUSE OF THE BEAM HEIGHT ISSUES. VIS AT DETROIT
LAKES HAS BEEN AROUND 1 TO 1 1/2 MILES FOR THE LAST FEW
HOURS...AND THE RAP HAS THE FRONTOGENESIS HANGING AROUND THROUGH
EARLY EVENING OVER WEST CENTRAL MINNESOTA. WILL EXTEND PART OF THE
ADVISORY UNTIL 03Z...BUT LET CASS...NORMAN...EASTERN POLK AND
NORTHERN CLEARWATER GO AS THE SNOW HAS ALREADY OR NEARLY CLEARED
THOSE AREAS.
UPDATE ISSUED AT 608 PM CST THU JAN 14 2016
PUT OUT A QUICK UPDATE TO TRIM THE WESTERN AND NORTHERN ENDS OF
THE ADVISORY OUT. THE WHOLE THING EXPIRES AT 7...AND WILL MONITOR
OVER THE NEXT HOUR AND DECIDE IF WE NEED TO EXTEND ANY PART OF THE
REMAINING COUNTIES OR IF THE BAND WILL DIMINISH ENOUGH TO LET IT
GO COMPLETELY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 318 PM CST THU JAN 14 2016
AS THE CURRENT SNOW EVENT WINDS DOWN...THE FOCUS WILL SHIFT BACK
TO THE COLD AND WIND CHILLS AGAIN. AS OF NOW...SEEING THE LIGHT
SNOW ENDING ACROSS THE DEVILS LAKE REGION. THE SNOW SHOULD BE
DECREASING ACROSS THE GRAND FORKS TO JAMESTOWN CORRIDOR IN THE
NEXT HOUR OR SO. THE SNOW WILL TAKE THE LONGEST TO CLEAR FROM
WEST CENTRAL MN. RADAR SHOWS THAT AREAS ALONG THE ND/SD BORDER
INTO WEST CENTRAL MN WILL BEGIN TO RECEIVE A LITTLE SNOW TOO OVER
THE NEXT FEW HOURS. NO SHIFT TO THE MAIN CORRIDOR OF 3 TO 5
INCHES...FROM NEW ROCKFORD TO HILLSBORO TO PARK RAPIDS...WHICH
WILL END FROM WEST TO EAST OVER THE NEXT FEW HOURS. CURRENT
ADVISORY ENDS AT 7 PM...BUT SHOULD BE ABLE TO TRIM SOME COUNTIES
FROM WEST TO EAST PRIOR TO THAT TIME. AFTER ADVISORY ENDS WILL BE
DEALING MORE WITH TEMPS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 318 PM CST THU JAN 14 2016
STILL LOOKING QUITE FRIGID THIS WEEKEND AND WILL BE DEALING WITH
WIND CHILL PRODUCTS FOR MOST OF IT.
A FRIGID ARCTIC AIRMASS WILL BE IN PLACE EARLY IN THE LONG
TERM...WITH TEMPERATURES BEING SUB ZERO THROUGH TUESDAY WHEN
DAYTIME HIGHS WILL BE IN LOW SINGLE DIGITS ABOVE ZERO. THIS SUPER
DRY AIRMASS WILL BE HARD TO OVERCOME...HOWEVER MODELS DO INDICATE
AN UPPER WAVE IN THE NW FLOW ALOFT MOVING ACROSS THE REGION IN THE
TUESDAY TIMEFRAME. THIS COULD PROVIDE A LIGHT DUSTING OF SNOW BUT
NOT SUFFICIENT MOISTURE FOR ANYTHING SIGNIFICANT. THE REMAINDER OF
THE WORK WEEK WILL BE DRY WITH MUCH MILDER (WARMER) TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1141 PM CST THU JAN 14 2016
VFR CIGS ARE SPREADING SOUTH AND EASTWARD AS THE CLEARING SPOT HAS
BEEN A BIT FASTER TO MOVE SOUTH THAN EXPECTED. SNOW HAS CLEARED
OUT OF ALL TAF SITES BUT KBJI...SOME BLSN OF AROUND 1 OR 2SM HAS
BEEN FOUND AT ISOLATED SPOTS ON AND OFF BUT AS WINDS DECREASE THAT
THREAT SHOULD DIMINISH. SOME CIGS STARTING TO MOVE IN WEST OF KDVL
ARE MOSTLY VFR ALTHOUGH A FEW SPOTS HAVE SHOWN SOME MVFR OR EVEN
IFR CIGS MIXED IN SO WILL HAVE TO KEEP A CLOSE EYE ON THE CLOUDS.
THE DECK OVER CANADA EXPECTED TO MOVE SOUTH LATER IN THE PERIOD
HAS NOT MADE MUCH PROGRESS. THUS...WILL HAVE VFR CONDITIONS
CONTINUE THROUGH TONIGHT...WITH A BIT OF VFR CIGS MOVING IN DURING
THE EARLY MORNING. WILL HOLD OFF ANY MVFR UNTIL LATE MORNING AT
KDVL OR AFTERNOON FURTHER SOUTH AND EAST. WINDS WILL CONTINUE TO
BE FROM THE NORTH TO NORTHWEST THROUGHOUT THE PERIOD WITH
DECREASING SPEEDS AS HIGH PRESSURE BUILDS INTO THE REGION.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...GODON/SPEICHER
AVIATION...JR
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1150 PM CST THU JAN 14 2016
.UPDATE...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR AREAS EAST OF
I-35 AND I-37. SURFACE OBSERVATIONS AND WEBCAMS ACROSS THIS REGION
OF THE CWA CONFIRM DENSE FOG HAS DEVELOPED OR IS IN THE PROCESS
OF DEVELOPING.
&&
.PREV DISCUSSION... /ISSUED 1059 PM CST THU JAN 14 2016/
AVIATION...
FOG HAS BEGUN TO FORM AND VIS AT SSF HAS BEEN BOUNCING BETWEEN
MVFR AND IFR. EXPECT THIS TREND TO CONTINUE FOR THE NEXT SEVERAL
HOURS IN SAN ANTONIO AND AUSTIN. DRT SHOULD REMAIN VFR THROUGH
THE NIGHT. WIND SHIFT TO THE WEST AND THEN NORTHWEST SHOULD BRING
DRIER AIR AND VFR CONDITIONS. NORTH TO NORTHWEST WINDS WILL
CONTINUE THROUGH THE DAY FRIDAY AT ALL TERMINALS.
PREV DISCUSSION... /ISSUED 1032 PM CST THU JAN 14 2016/
UPDATE...BASED ON CURRENT AND EXPECTED TRENDS, PATCHY AND AREAS
OF FOG HAVE BEEN INTRODUCED ALONG THE I-35/37 CORRIDOR AND EAST
INTO THE SOUTHEAST COASTAL PLAINS. SOME LOCATIONS ACROSS FAR
SOUTHEAST COUNTIES LIKE LAVACA...FAYETTE...AND PORTIONS OF
GONZALES AND DEWITT COULD EXPERIENCE SOME AREAS OF DENSE FOG.
THIS WORDING HAS BEEN INTRODUCED INTO THE LATE EVENING AS WELL AS
THE OVERNIGHT GRIDS WILL SUPPORT FROM THE HRRR AND NAM BUFR
SOUNDINGS. A DRYLINE/PACIFIC FRONT WILL MOVE THROUGH EARLY FRIDAY
AND HELP CLEAR THE FOG BY 8 TO 9AM. NO OTHER WEATHER UPDATES WERE
MADE AND THE UPDATED ZONES ARE OUT.
PREV DISCUSSION... /ISSUED 236 PM CST THU JAN 14 2016/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
THE UPPER LEVEL LOW IS CURRENTLY CENTERED NEAR EDWARDS COUNTY AND
CONTINUES TO MOVE EAST. THE MAIN SHOWER AND THUNDERSTORM ACTIVITY
IS WELL OFF THE COAST AND CHANCES FOR RAIN FOR OUR CWA ARE FAIRLY
LOW FOR THE REST OF THE AFTERNOON. WILL CARRY NO POPS FOR THE
TONIGHT PERIOD AS ALL ACTIVITY SHOULD BE FARTHER EAST OF THE
REGION. A WEAK FRONTAL BOUNDARY IS EXPECTED TO PUSH THROUGH THE
REGION OVERNIGHT BEHIND THE DEPARTING LOW PRESSURE SYSTEM. LOWS
TONIGHT SHOULD BE IN THE 40S ACROSS MUCH OF THE AREA WITH THE
SLIGHTLY COOLER READINGS ACROSS THE NORTHWEST CWA WHERE THE FRONT
MOVES IN A BIT EARLIER. WINDS ARE EXPECTED TO RETURN TO THE SOUTH
BY TOMORROW AFTERNOON AND HIGH TEMPERATURES ARE EXPECTED TO REACH
THE UPPER 60S TO LOWER 70S. WITH DEWPOINTS REMAINING IN THE MID-
20S TOMORROW AFTERNOON...HUMIDITY VALUES WILL BOTTOM OUT IN THE
TEENS ACROSS THE WESTERN COUNTIES BUT WINDS SHOULD REMAIN BELOW 15
MPH. LOWS FRIDAY NIGHT SHOULD BE IN THE 40S ONCE AGAIN MOSTLY
CLEAR TO PARTLY CLOUDY SKIES.
LONG TERM (SATURDAY THROUGH THURSDAY)...
THE NEXT SHORTWAVE IS EXPECTED TO PUSH THROUGH THE AREA SATURDAY
MORNING. THIS SMALL BUT STRONG SYSTEM WILL BRING A SMALL CHANCE OF
RAIN TO MAINLY THE EASTERN COUNTIES SATURDAY AFTERNOON. BEHIND THE
SYSTEM WINDS WILL BE QUITE STRONG DURING THE AFTERNOON HOURS
ACROSS THE WESTERN COUNTIES. MODELS ARE SHOWING 850 WINDS OUT OF
THE NORTHWEST AROUND 40 KNOTS. SHOULD SEE ENOUGH MIXING TO HAVE
SUSTAINED 20-25 MPH WINDS AT THE SURFACE AT LEAST. SHOULD BE CLOSE
TO WIND ADVISORY CRITERIA FOR THIS AREA...BUT WILL PROBABLY JUST
BELOW THE 26 MPH SUSTAINED CRITERIA. HUMIDITY VALUES WILL BE
HIGHER THAN FRIDAY AND NOT EXPECTING MUCH OF A FIRE WEATHER ISSUE
ESPECIALLY WITH CONTINUED MOIST FUELS. ANOTHER WEAK FRONT IS
EXPECTED TUESDAY NIGHT...BUT WILL NOT HAVE MUCH OF AN EFFECT ON
RAIN CHANCES OR TEMPERATURES. A STRONGER SYSTEM IS EXPECTED AROUND
NEXT THURSDAY WHICH COULD BRING OUR NEXT CHANCES OF RAIN...MAINLY
IN THE EASTERN COUNTIES ONCE AGAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 47 68 42 60 35 / 0 0 0 20 0
AUSTIN BERGSTROM INTL AIRPORT 44 67 38 60 34 / 0 0 0 20 0
NEW BRAUNFELS MUNI AIRPORT 45 69 40 63 33 / 0 0 0 20 0
BURNET MUNI AIRPORT 43 65 40 55 33 / 0 0 0 20 0
DEL RIO INTL AIRPORT 42 71 44 65 36 / 0 0 0 - 0
GEORGETOWN MUNI AIRPORT 45 66 39 56 32 / 0 0 0 20 0
HONDO MUNI AIRPORT 44 71 42 65 34 / 0 0 0 10 0
SAN MARCOS MUNI AIRPORT 45 68 40 61 34 / 0 0 0 20 0
LA GRANGE - FAYETTE REGIONAL 50 68 42 62 34 / 10 0 - 20 -
SAN ANTONIO INTL AIRPORT 47 70 43 63 37 / 0 0 0 10 0
STINSON MUNI AIRPORT 46 71 43 64 37 / 0 0 0 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM CST FRIDAY FOR THE FOLLOWING
COUNTIES: BASTROP...CALDWELL...DE WITT...FAYETTE...GONZALES...
GUADALUPE...KARNES...LAVACA...LEE...WILSON.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...RUNYEN
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1130 PM CST THU JAN 14 2016
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...WEST SOUTHWEST FLOW ABOVE THE DECK SHOULD BECOME MORE
NORTHWEST AS A TROUGH MOVES EAST OF THE AREA. THE SOUNDING SHOWS
WIDENING TEMP/DEW POINT SPREAD ABOVE THE DECK AND THE POTENTIAL FOR
BOUNDARY LAYER COOLING WITH A LOW LEVEL SURFACE BASED INVERSION
SUPPORTING FOG. HRRR DEW POINT DEPRESSION WILL BE LESS THAN A DEGREE
ALONG THE COAST THROUGH DAWN. LIGHT WINDS...MOSTLY CLEAR SKIES...
ELEVATED DEW POINTS (RELATIVE TO TEMPS) AND SOME GROUND MOISTURE
COULD CONTRIBUTE TO OVERNIGHT FOG. HRRR SURFACE WINDS VEERING FROM
SOUTH TO SOUTHWEST OVERNIGH PROBABLY WON`T SUPPORT FOG HOWEVER.
THE MODEL GUIDANCE HAS DEFINITELY BEEN SOMEWHAT INCONSISTENT WITH
THE EXTENT AND AMOUNT OF FOG...WITH THE 00Z MAV GUIDANCE AGAIN
ADVERTISING SOME DENSE FOG IN THE PREDAWN HOURS FOR THE TAF SITES.
NOT READY TO JUMP ON WIDESPREAD DENSE JUST YET...BUT AVIATION
CONDITIONS COULD STILL DROP TO LIFR CIGS/VSBY IN LOW CLOUDS/FOG
THROUGH MORNING. ADDITIONAL ANALYSIS ONGOING.
&&
.PREV DISCUSSION... /ISSUED 547 PM CST THU JAN 14 2016/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR TAFS UNTIL ABOUT MIDNIGHT...THEN A POSSIBLE DROP
TO LIFR CIGS/VSBY IN LOW CLOUDS/FOG THROUGH MORNING. THE MODEL
GUIDANCE HAS DEFINITELY BEEN SOMEWHAT INCONSISTENT WITH THE
EXTENT AND AMOUNT OF FOG...WITH THE 18Z MAV GUIDANCE AGAIN
ADVERTISING SOME DENSE IN THE PREDAWN HOURS FOR THE TAF SITES.
LIGHT WINDS...MOSTLY CLEAR SKIES...ELEVATED DEW POINTS (RELATIVE
TO TEMPS) AND SOME GROUND MOISTURE COULD CONTRIBUTE TO OVERNIGHT
FOG...AND WILL INCLUDE IN THE TAFS FOR NOW...WITH ADDITIONAL
ANALYSIS ONGOING.
PREV DISCUSSION... /ISSUED 154 PM CST THU JAN 14 2016/
SHORT TERM /NOW THROUGH FRIDAY NIGHT/...LATEST WATER VAPOR IMAGERY
SHOWS 500MB TROUGH CURRENTLY OVER WEST CENTRAL TEXAS WILL BE MOVING
EAST AND EXIST THE STATE DURING THE SHORT TERM PERIOD. COASTAL
TROUGH GENERATED BY THIS TROUGH WILL LIFT NORTHEAST ALONG THE GULF
COAST AND CONTINUE TO ENHANCE A FEW ISOLATED SHOWERS IN THE
OFFSHORE WATERS. THE MID AND LOW LEVEL CLOUD COVER REMAINED OVC TO
BKN ACROSS MUCH THE CWA LIMITING MUCH HEATING TO REACH THE GROUND
AND FOR ANY CONVECTION TO INITIATE. THE CLOUD COVER IN ADDITION TO
THE LOCATION OF THE TROUGH IS NOT FAVORABLY FOR ACTIVITY TO DEVELOP
ACROSS THE AREA. A FEW ISOLATED SHOWERS CAN NOT BE RULED OUT BUT
MAINLY ALONG THE COAST AND OFFSHORE WATERS. TEMPERATURES WILL REACH
THE MID 70S AREAS ALONG THE COAST AND IN THE LOW 70S FURTHER INLAND.
AS THE TROUGH MOVES EAST...DRY AIR MAKES ITS WAY INTO THE AREA
TONIGHT BECOMING CLEAR OVERNIGHT. TEMPERATURES WILL BE A COOLING
INTO THE UPPER 40S OVER THE NORTHERN RANCHLANDS AND WESTERN COUNTIES
WHILE TOWARDS THE EAST COAST REMAIN IN THE MID 50S WITH A LIGHT
SOUTH TO SOUTHWEST FLOW.
FRIDAY...NORTHWEST FLOW ALOFT RETURNS AS RIDGE BEGINS TO BUILD
ACROSS THE REGION. A WEST TO NORTHWEST FLOW NEAR THE SURFACE WITH
ABUNDANT DRY SLOT IN THE AREA WILL FAVOR WARMER TEMPERATURES FRIDAY.
HIGH TEMPS WILL BE IN THE 80S ALONG THE COAST AND UPPER 70S ACROSS
THE WEST WITH CLEAR SKIES. HUMIDITY WILL LOWER INTO THE TEEN WITH
WINDS BUT WINDS WILL REMAIN LIGHT TO MODERATE WHICH WILL LIMIT THE
POTENTIAL FOR FIRE WEATHER CONCERN DURING THE DAY.
LONG TERM /SATURDAY THROUGH THURSDAY/...THE MOST SIGNIFICANT
WEATHER EVENT IN THE LONG TERM PORTION OF THE FORECAST WILL BE THE
SATURDAY MORNING AND AFTERNOON PASSAGE OF A STRONG COLD FRONT IN
ASSOCIATION WITH THE EASTWARD PROGRESSION OF A CLOSED 500 MB LOW
PRESSURE SYSTEM THROUGH THE LONE STAR STATE. ISOLATED/SCATTERED
PRECIPITATION WILL ACCOMPANY THE FRONTAL PASSAGE IN DEEP SOUTH
TEXAS AND THE RIO GRANDE VALLEY...WITH MEX GUIDANCE SUGGESTING
WIND SPEEDS IN THE WAKE OF THE FRONT MAY REACH WIND ADVISORY
CRITERIA FOR ALL OR PORTIONS OF THE BRO CWFA. AFTERWARDS AND FOR
THE REMAINDER OF THE LONG TERM FORECAST PERIOD...A NEARLY ZONAL
500 MB FLOW WILL ALLOW A SERIES OF ONLY WEAK COLD FRONTS TO PASS
THROUGH THE BRO CWFA OR NEAR THE AREA FROM THE NORTH...WITH
ISOLATED RAINFALL NOT RE-ENTERING THE FORECAST UNTIL WEDNESDAY.
TEMPERATURE-WISE...DESPITE THE COLD FRONTAL APPROACHES AND/OR
PASSAGES...NEAR TO ABOVE NORMAL DAYTIME HIGH AND OVERNIGHT LOW
TEMPERATURES ARE ANTICIPATED.
MARINE...NOW THROUGH FRIDAY NIGHT...UPPER TROUGH MOVING EAST ACROSS
THE STATE OF TEXAS WILL LIFT A COASTAL TROUGH NORTHEAST ALONG THE
WESTERN GULF COAST. THIS WILL ENHANCE A FEW ISOLATED SHOWERS OVER
THE OFFSHORE WATERS BUT WILL LIFT AND EXIT NORTHEAST FURTHER OUT
INTO THE GULF. DRY AIR RIGHT BEHIND THIS SYSTEM WILL RETURN WITH A
WEST TO NORTHWEST FLOW AS RIDGE BUILDS ACROSS THE REGION. LIGHT AND
MODERATE WINDS WILL PREVAIL THROUGH THE PERIOD ALLOWING SEAS TO
REMAIN BELOW 2 TO 3 FEET.
SATURDAY THROUGH THURSDAY...LIKELY SMALL CRAFT ADVISORY AND
POSSIBLE GALE WARNING CONDITIONS ARE ANTICIPATED ALONG THE LOWER
TEXAS COAST SATURDAY AFTERNOON AND SATURDAY NIGHT DUE TO THE
PASSAGE OF A COLD FRONT. FOR THE REMAINDER OF THE FORECAST
PERIOD...LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS WILL
PREVAIL AS A SERIES OF WEAK COLD FRONTS PASS THROUGH THE LOWER
TEXAS COAST WATERS OR APPROACH THE AREA FROM THE NORTH.
BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 73 57 78 55 / 50 0 0 0
BROWNSVILLE 72 55 80 54 / 40 0 0 0
HARLINGEN 73 54 82 52 / 50 0 0 0
MCALLEN 74 52 82 52 / 30 0 0 0
RIO GRANDE CITY 75 50 80 50 / 20 0 0 0
SOUTH PADRE ISLAND 69 59 73 59 / 50 0 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
54...AVIATION
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1059 PM CST THU JAN 14 2016
.AVIATION...
FOG HAS BEGUN TO FORM AND VIS AT SSF HAS BEEN BOUNCING BETWEEN
MVFR AND IFR. EXPECT THIS TREND TO CONTINUE FOR THE NEXT SEVERAL
HOURS IN SAN ANTONIO AND AUSTIN. DRT SHOULD REMAIN VFR THROUGH
THE NIGHT. WIND SHIFT TO THE WEST AND THEN NORTHWEST SHOULD BRING
DRIER AIR AND VFR CONDITIONS. NORTH TO NORTHWEST WINDS WILL
CONTINUE THROUGH THE DAY FRIDAY AT ALL TERMINALS.
&&
.PREV DISCUSSION... /ISSUED 1032 PM CST THU JAN 14 2016/
UPDATE...BASED ON CURRENT AND EXPECTED TRENDS, PATCHY AND AREAS
OF FOG HAVE BEEN INTRODUCED ALONG THE I-35/37 CORRIDOR AND EAST
INTO THE SOUTHEAST COASTAL PLAINS. SOME LOCATIONS ACROSS FAR
SOUTHEAST COUNTIES LIKE LAVACA...FAYETTE...AND PORTIONS OF
GONZALES AND DEWITT COULD EXPERIENCE SOME AREAS OF DENSE FOG.
THIS WORDING HAS BEEN INTRODUCED INTO THE LATE EVENING AS WELL AS
THE OVERNIGHT GRIDS WILL SUPPORT FROM THE HRRR AND NAM BUFR
SOUNDINGS. A DRYLINE/PACIFIC FRONT WILL MOVE THROUGH EARLY FRIDAY
AND HELP CLEAR THE FOG BY 8 TO 9AM. NO OTHER WEATHER UPDATES WERE
MADE AND THE UPDATED ZONES ARE OUT.
PREV DISCUSSION... /ISSUED 236 PM CST THU JAN 14 2016/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
THE UPPER LEVEL LOW IS CURRENTLY CENTERED NEAR EDWARDS COUNTY AND
CONTINUES TO MOVE EAST. THE MAIN SHOWER AND THUNDERSTORM ACTIVITY
IS WELL OFF THE COAST AND CHANCES FOR RAIN FOR OUR CWA ARE FAIRLY
LOW FOR THE REST OF THE AFTERNOON. WILL CARRY NO POPS FOR THE
TONIGHT PERIOD AS ALL ACTIVITY SHOULD BE FARTHER EAST OF THE
REGION. A WEAK FRONTAL BOUNDARY IS EXPECTED TO PUSH THROUGH THE
REGION OVERNIGHT BEHIND THE DEPARTING LOW PRESSURE SYSTEM. LOWS
TONIGHT SHOULD BE IN THE 40S ACROSS MUCH OF THE AREA WITH THE
SLIGHTLY COOLER READINGS ACROSS THE NORTHWEST CWA WHERE THE FRONT
MOVES IN A BIT EARLIER. WINDS ARE EXPECTED TO RETURN TO THE SOUTH
BY TOMORROW AFTERNOON AND HIGH TEMPERATURES ARE EXPECTED TO REACH
THE UPPER 60S TO LOWER 70S. WITH DEWPOINTS REMAINING IN THE MID-
20S TOMORROW AFTERNOON...HUMIDITY VALUES WILL BOTTOM OUT IN THE
TEENS ACROSS THE WESTERN COUNTIES BUT WINDS SHOULD REMAIN BELOW 15
MPH. LOWS FRIDAY NIGHT SHOULD BE IN THE 40S ONCE AGAIN MOSTLY
CLEAR TO PARTLY CLOUDY SKIES.
LONG TERM (SATURDAY THROUGH THURSDAY)...
THE NEXT SHORTWAVE IS EXPECTED TO PUSH THROUGH THE AREA SATURDAY
MORNING. THIS SMALL BUT STRONG SYSTEM WILL BRING A SMALL CHANCE OF
RAIN TO MAINLY THE EASTERN COUNTIES SATURDAY AFTERNOON. BEHIND THE
SYSTEM WINDS WILL BE QUITE STRONG DURING THE AFTERNOON HOURS
ACROSS THE WESTERN COUNTIES. MODELS ARE SHOWING 850 WINDS OUT OF
THE NORTHWEST AROUND 40 KNOTS. SHOULD SEE ENOUGH MIXING TO HAVE
SUSTAINED 20-25 MPH WINDS AT THE SURFACE AT LEAST. SHOULD BE CLOSE
TO WIND ADVISORY CRITERIA FOR THIS AREA...BUT WILL PROBABLY JUST
BELOW THE 26 MPH SUSTAINED CRITERIA. HUMIDITY VALUES WILL BE
HIGHER THAN FRIDAY AND NOT EXPECTING MUCH OF A FIRE WEATHER ISSUE
ESPECIALLY WITH CONTINUED MOIST FUELS. ANOTHER WEAK FRONT IS
EXPECTED TUESDAY NIGHT...BUT WILL NOT HAVE MUCH OF AN EFFECT ON
RAIN CHANCES OR TEMPERATURES. A STRONGER SYSTEM IS EXPECTED AROUND
NEXT THURSDAY WHICH COULD BRING OUR NEXT CHANCES OF RAIN...MAINLY
IN THE EASTERN COUNTIES ONCE AGAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 47 68 42 60 35 / 0 0 0 20 0
AUSTIN BERGSTROM INTL AIRPORT 44 67 38 60 34 / 0 0 0 20 0
NEW BRAUNFELS MUNI AIRPORT 45 69 40 63 33 / 0 0 0 20 0
BURNET MUNI AIRPORT 43 65 40 55 33 / 0 0 0 20 0
DEL RIO INTL AIRPORT 42 71 44 65 36 / 0 0 0 - 0
GEORGETOWN MUNI AIRPORT 45 66 39 56 32 / 0 0 0 20 0
HONDO MUNI AIRPORT 44 71 42 65 34 / 0 0 0 10 0
SAN MARCOS MUNI AIRPORT 45 68 40 61 34 / 0 0 0 20 0
LA GRANGE - FAYETTE REGIONAL 50 68 42 62 34 / 10 0 - 20 -
SAN ANTONIO INTL AIRPORT 47 70 43 63 37 / 0 0 0 10 0
STINSON MUNI AIRPORT 46 71 43 64 37 / 0 0 0 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...ALLEN
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1032 PM CST THU JAN 14 2016
.UPDATE...BASED ON CURRENT AND EXPECTED TRENDS, PATCHY AND AREAS
OF FOG HAVE BEEN INTRODUCED ALONG THE I-35/37 CORRIDOR AND EAST
INTO THE SOUTHEAST COASTAL PLAINS. SOME LOCATIONS ACROSS FAR
SOUTHEAST COUNTIES LIKE LAVACA...FAYETTE...AND PORTIONS OF
GONZALES AND DEWITT COULD EXPERIENCE SOME AREAS OF DENSE FOG.
THIS WORDING HAS BEEN INTRODUCED INTO THE LATE EVENING AS WELL AS
THE OVERNIGHT GRIDS WILL SUPPORT FROM THE HRRR AND NAM BUFR
SOUNDINGS. A DRYLINE/PACIFIC FRONT WILL MOVE THROUGH EARLY FRIDAY
AND HELP CLEAR THE FOG BY 8 TO 9AM. NO OTHER WEATHER UPDATES WERE
MADE AND THE UPDATED ZONES ARE OUT.
&&
.PREV DISCUSSION... /ISSUED 547 PM CST THU JAN 14 2016/
AVIATION...
SOUTHERLY WINDS WILL CONTINUE TO BRING LOW LEVEL MOISTURE INTO THE
REGION THIS EVENING AND IFR CIGS WILL DEVELOP IN AUSTIN AND SAN
ANTONIO BY AROUND 03Z. A WIND SHIFT TO THE WEST OR NORTHWEST WILL
BRING IN DRIER AIR AND DRIVE OUT THE LOW CLOUDINESS AFTER 06Z TO
10Z. ALL TERMINALS WILL REMAIN VFR THROUGH THE END OF THE PERIOD.
PREV DISCUSSION... /ISSUED 236 PM CST THU JAN 14 2016/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
THE UPPER LEVEL LOW IS CURRENTLY CENTERED NEAR EDWARDS COUNTY AND
CONTINUES TO MOVE EAST. THE MAIN SHOWER AND THUNDERSTORM ACTIVITY
IS WELL OFF THE COAST AND CHANCES FOR RAIN FOR OUR CWA ARE FAIRLY
LOW FOR THE REST OF THE AFTERNOON. WILL CARRY NO POPS FOR THE
TONIGHT PERIOD AS ALL ACTIVITY SHOULD BE FARTHER EAST OF THE
REGION. A WEAK FRONTAL BOUNDARY IS EXPECTED TO PUSH THROUGH THE
REGION OVERNIGHT BEHIND THE DEPARTING LOW PRESSURE SYSTEM. LOWS
TONIGHT SHOULD BE IN THE 40S ACROSS MUCH OF THE AREA WITH THE
SLIGHTLY COOLER READINGS ACROSS THE NORTHWEST CWA WHERE THE FRONT
MOVES IN A BIT EARLIER. WINDS ARE EXPECTED TO RETURN TO THE SOUTH
BY TOMORROW AFTERNOON AND HIGH TEMPERATURES ARE EXPECTED TO REACH
THE UPPER 60S TO LOWER 70S. WITH DEWPOINTS REMAINING IN THE MID-
20S TOMORROW AFTERNOON...HUMIDITY VALUES WILL BOTTOM OUT IN THE
TEENS ACROSS THE WESTERN COUNTIES BUT WINDS SHOULD REMAIN BELOW 15
MPH. LOWS FRIDAY NIGHT SHOULD BE IN THE 40S ONCE AGAIN MOSTLY
CLEAR TO PARTLY CLOUDY SKIES.
LONG TERM (SATURDAY THROUGH THURSDAY)...
THE NEXT SHORTWAVE IS EXPECTED TO PUSH THROUGH THE AREA SATURDAY
MORNING. THIS SMALL BUT STRONG SYSTEM WILL BRING A SMALL CHANCE OF
RAIN TO MAINLY THE EASTERN COUNTIES SATURDAY AFTERNOON. BEHIND THE
SYSTEM WINDS WILL BE QUITE STRONG DURING THE AFTERNOON HOURS
ACROSS THE WESTERN COUNTIES. MODELS ARE SHOWING 850 WINDS OUT OF
THE NORTHWEST AROUND 40 KNOTS. SHOULD SEE ENOUGH MIXING TO HAVE
SUSTAINED 20-25 MPH WINDS AT THE SURFACE AT LEAST. SHOULD BE CLOSE
TO WIND ADVISORY CRITERIA FOR THIS AREA...BUT WILL PROBABLY JUST
BELOW THE 26 MPH SUSTAINED CRITERIA. HUMIDITY VALUES WILL BE
HIGHER THAN FRIDAY AND NOT EXPECTING MUCH OF A FIRE WEATHER ISSUE
ESPECIALLY WITH CONTINUED MOIST FUELS. ANOTHER WEAK FRONT IS
EXPECTED TUESDAY NIGHT...BUT WILL NOT HAVE MUCH OF AN EFFECT ON
RAIN CHANCES OR TEMPERATURES. A STRONGER SYSTEM IS EXPECTED AROUND
NEXT THURSDAY WHICH COULD BRING OUR NEXT CHANCES OF RAIN...MAINLY
IN THE EASTERN COUNTIES ONCE AGAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 47 68 42 60 35 / 0 0 0 20 0
AUSTIN BERGSTROM INTL AIRPORT 44 67 38 60 34 / 0 0 0 20 0
NEW BRAUNFELS MUNI AIRPORT 45 69 40 63 33 / 0 0 0 20 0
BURNET MUNI AIRPORT 43 65 40 55 33 / 0 0 0 20 0
DEL RIO INTL AIRPORT 42 71 44 65 36 / 0 0 0 - 0
GEORGETOWN MUNI AIRPORT 45 66 39 56 32 / 0 0 0 20 0
HONDO MUNI AIRPORT 44 71 42 65 34 / 0 0 0 10 0
SAN MARCOS MUNI AIRPORT 45 68 40 61 34 / 0 0 0 20 0
LA GRANGE - FAYETTE REGIONAL 50 68 42 62 34 / 10 0 - 20 -
SAN ANTONIO INTL AIRPORT 47 70 43 63 37 / 0 0 0 10 0
STINSON MUNI AIRPORT 46 71 43 64 37 / 0 0 0 10 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...ALLEN
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
751 AM EST FRI JAN 15 2016
.UPDATE...
ISSUED AT 751 AM EST FRI JAN 15 2016
FRESHENED UP THE HOURLY TEMPERATURES AND DEW POINTS. SHELTERED
VALLEYS ARE RANGING FROM THE MID 20S TO THE LOWER 30S...WITH MOST
OTHER LOCATIONS REPORTING IN THE LOW TO MID 40S. THICKER CLOUDS
ARE STARTING TO OVERTAKE THE AREA...WITH RAIN SHOWERS MOVING IN
ACROSS PORTIONS OF WESTERN KENTUCKY. THE LATEST HRRR GUIDANCE
CONTINUES TO SHOW LITTLE IN THE WAY OF SHOWER ACTIVITY UNTIL THIS
AFTERNOON...WHEN THE FAR SOUTHEAST MAY GET BRUSHED. WILL LET THE
CURRENT FORECAST RIDE FOR NOW. GRID UPDATES WILL BE FORTHCOMING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
SURFACE LOW PRESSURE IS CURRENTLY CRUISING TOWARDS THE GREAT
LAKES...WITH AN ATTENDANT COLD FRONT ALIGNED SOUTHWEST THROUGH THE
SOUTHERN PLAINS. ANOTHER LOW PRESSURE SYSTEM IS ORGANIZING ACROSS
THE NORTH CENTRAL GULF OF MEXICO...WITH HIGH PRESSURE RETREATING
OFF THE CAROLINA COAST. ALOFT...A SHORT WAVE TROUGH IS MOVING
ACROSS THE PLAINS WITHIN THE NORTHERN STREAM...WHILE ANOTHER ONE
IS MOVING THROUGH THE NORTH CENTRAL GULF WITHIN THE SOUTHERN
STREAM. THIS IS ALLOWING FOR DEEPER SOUTHWEST FLOW ACROSS THE MID
AND LOWER MISSISSIPPI VALLEY...WITH PLENTY OF HIGH CLOUDS
STREAMING IN FROM THE SOUTHWEST. EASTERN KENTUCKY REMAINS UNDER
PARTLY CLOUDY TO MOSTLY CLEAR SKIES...WITH TEMPERATURES VARYING
FROM THE MID TO UPPER 40S IN THE BROADER VALLEYS AND
RIDGETOPS...WHILE SHELTERED VALLEYS IN THE EAST REMAIN SOME 20
DEGREES COLDER...IN THE MID TO UPPER 20S.
THE TWO AFOREMENTIONED SYSTEMS WILL TRACK EAST TODAY...WITH
EASTERN KENTUCKY REMAINING SPLIT BETWEEN THEM. THE MODELS HAVE
TRENDED A BIT DRIER WITH THE SOUTHERN STREAM MOISTURE...KEEPING
MOST OF THIS JUST TO OUR SOUTHEAST. MOST OF THE FORCING WILL COME
FROM THE NORTHERN STREAM SYSTEM AS THE TROUGH AXIS AND SURFACE
COLD FRONT APPROACH FROM THE WEST. LIGHT RAIN SHOWERS WILL MOVE IN
FROM THE WEST TODAY...WITH THE MAJORITY OF THE ACTIVITY HOLDING
OFF UNTIL THIS AFTERNOON. THE BEST OVERALL RAIN CHANCES STILL LOOK
TO OCCUR IN THE FAR WEST...WITH LESSER CHANCES IN OUR NORTHEAST
COUNTIES. HIGHS TODAY WILL RECOVER INTO THE LOW TO MID 50S...WITH
SOME SPOTS REACHING THE UPPER 50S IN THE EAST...WHERE THICKER
CLOUD COVER WILL HOLD OFF THE LONGEST.
THE COLD FRONT AND TROUGH AXIS WILL SWING THROUGH THE AREA BETWEEN
00 AND 06Z TONIGHT...WITH A GOOD CHANCE OF LIGHT PRECIPITATION
CONTINUING. COLD ADVECTION WILL BE UNDERWAY OVERNIGHT...WITH LOWS
FOR MOST COOLING OFF TO THE LOW TO MID 30S. THE ONLY EXCEPTION
WILL BE THE HIGHER TERRAIN...WHERE LOWS WILL SETTLE INTO THE 20S.
HAVE LEFT A MENTION OF SNOW IN THE FORECAST TOWARDS DAWN SATURDAY
MORNING...HOWEVER WITH ICE IN QUESTION...DRIZZLE AND OR FREEZING
DRIZZLE MAY BECOME A CONCERN FOR THE HIGHER ELEVATIONS.
ANY LIGHT PRECIPITATION LINGERING INTO SATURDAY WILL TAPER OFF
DURING THE DAY AS FORCING DIMINISHES. HIGH TEMPERATURES WILL NOT
RECOVER MUCH DURING THE DAY WITH THICK CLOUD COVER LOCKED INTO
PLACE THANKS TO A POST-FRONTAL INVERSION. HAVE UNDERCUT THE
BLENDED GUIDANCE FOR THE HIGHS...ONLY ALLOWING FOR A FEW DEGREE
OR SO RISE FROM SATURDAY MORNING LOWS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
...COLDEST AIR OF SEASON LIKELY SUNDAY NIGHT THROUGH MONDAY NIGHT...
MODELS REMAIN IN DECENT AGREEMENT ON THE MID/UPPER LEVEL PATTERN
THROUGH TUESDAY...BUT REMAIN FARTHER APART FROM WEDNESDAY ONWARD.
THE MAIN HEADLINE THROUGH THE EXTENDED WILL BE THE ARCTIC COLD FOR
EARLY NEXT WEEK.
SATURDAY NIGHT INTO SUNDAY...A QUICK MOVING SHORTWAVE TROUGH WILL
CROSS THE SOUTHERN APPALACHIANS AND COULD SEND SOME LIGHT SNOW
ACROSS SOUTHEAST KENTUCKY EARLY SUNDAY MORNING. STILL SOME QUESTION
ON HOW FAR BACK TO THE NORTHWEST THE SNOWFALL EXTENDS...BUT OUR
COUNTIES BORDERING VIRGINIA STAND A DECENT CHANCE TO SEE SOME LIGHT
SNOW AND POTENTIALLY A LIGHT COATING OF SNOW. THIS SYSTEM WILL BE
FASTER MOVING...SO SNOW CHANCES WILL QUICKLY DIMINISH SUNDAY
MORNING WITH CLOUDS POSSIBLY PARTING WAYS BY LATE MORNING INTO THE
AFTERNOON. WITH SOME SUNSHINE...CERTAINLY POSSIBLE HIGHS WILL MAKE
A BOUNCE UP IN TO THE MID TO UPPER 30S.
AN ARCTIC FRONT WILL THEN DROP SOUTH SUNDAY EVENING WITH COLD AIR
SURGING ACROSS KENTUCKY. LOWS BY MONDAY MORNING WILL BE WELL INTO
THE TEENS AND WE MAY NOT SEE TEMPERATURES CLIMB MUCH AT ALL ON
MONDAY. MOISTURE WITH THE FRONT REMAINS VERY LIMITED...AND
WOULDN`T EXPECT MORE THAN SOME FLURRIES WITH THE FRONTAL PASSAGE.
GIVEN THE COLD AIR...WE COULD MAINTAIN SOME FLURRIES WELL INTO
MONDAY MORNING...EVEN WITH THE LACK OF DECENT CLOUD COVER.
SHOULDN`T TAKE MUCH WITH USPLOPE FLOW TO SQUEEZE OUT FLURRIES IN
THIS COLD AIR MASS. BY MONDAY NIGHT...HIGH PRESSURE WILL BUILD
INTO THE REGION WITH LOWS FALLING TO AROUND ZERO IN THE
VALLEYS...SETTING UP THE COLDEST NIGHT THUS FAR THIS WINTER. WITH
THE HELP OF SUNSHINE ON TUESDAY WE SHOULD SEE TEMPERATURES CLIMB
BACK INTO THE 20S.
00Z ECMWF TRENDED SLIGHTLY TOWARDS THE GFS SOLUTION OF A CLIPPER
SYSTEM FOR WEDNESDAY. THIS WOULD SUPPORT SOME LIGHT SNOW
OVERSPREADING THE AREA ON WEDNESDAY WITH SOME LIGHT SNOW
ACCUMULATIONS POSSIBLE. TEMPERATURES MAY CREEP ABOVE FREEZING ON
WEDNESDAY...BUT ANY PRECIPITATION WILL REMAIN ALL SNOW BASED ON THE
TOP DOWN METHOD ON THE SOUNDING. WITH THE ECMWF TRENDING TOWARDS THE
GFS...WE MAY DRY THINGS OUT LATE WEDNESDAY NIGHT INTO THURSDAY
BEFORE ANOTHER SYSTEM POSSIBLY MOVES INTO THE REGION LATE IN THE
WEEK. REGARDLESS...MODELS STILL REMAIN FAR APART...SO WILL JUST
BRING IN SOME SLIGHT CHANCE POPS TOWARDS THE TAIL END OF THE
FORECAST AND LEAVE THEM FAIRLY LOW WITH THIS DEGREE OF LOW
CONFIDENCE. IT DOES APPEAR TEMPERATURES SHOULD WARM LATE IN THE
WEEK...SUPPORTING AN ALL RAIN EVENT IF A SYSTEM DOES MATERIALIZE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 751 AM EST FRI JAN 15 2016
VFR CONDITIONS WILL HOLD ON THROUGH EARLY THIS AFTERNOON...WITH
MAINLY JUST PASSING HIGH CLOUDS TO CONTEND WITH UNTIL AFTER 18Z.
CEILINGS WILL THEN LOWER MORE QUICKLY DOWN TO MVFR FROM WEST TO
EAST...BETWEEN 21Z AND 00Z SATURDAY...WITH LIGHT RAIN SHOWERS
MOVING IN FROM THE WEST. A COLD FRONT WILL PASS THROUGH THIS
EVENING...WITH CEILINGS DROPPING DOWN TO IFR BEHIND THE BOUNDARY.
VERY LIGHT RAIN/DRIZZLE WILL LIKELY PERSIST INTO THE OVERNIGHT.
SOUTH WINDS OF 5 TO 10 KTS WILL REMAIN IN PLACE UNTIL THE FRONTAL
PASSAGE BETWEEN 00Z AND 06Z SATURDAY...WITH WINDS THEN TURNING
MORE TO THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS GAYLORD MI
955 AM EST FRI JAN 15 2016
.UPDATE...
ISSUED AT 949 AM EST FRI JAN 15 2016
AREAS FROM GAYLORD NORTH AND HIGHER TERRAIN WILL CONTINUE TO SEE
FZDZ THROUGH MIDDAY. 12Z KAPX SOUNDING SHOWED CLASSIC FREEZING
DRIZZLE PROFILE WITH MID LEVEL DRYING/SATURATED LAYER ABOVE -5C
AND BELOW 0C. SFC LOW NORTH OF MKX WILL MOVE EAST TODAY ACROSS THE
REGION PULLING A COLD FRONT THROUGH LATER TODAY. AS THE LOW PUSHES
THROUGH THE REGION EXPECT SATURATED LAYER TO INCREASE LEADING TO
MORE RAIN/SNOW INSTEAD OF FREEZING DRIZZLE. TEMPERATURES SHOULD
GET TO ABOVE/AROUND 32F TODAY ACROSS NORTHERN LOWER WITH MAINLY
20S ACROSS EASTERN UPPER WITH A COUPLE INCHES OF SNOW POSSIBLE
NORTH BY EVENING.
&&
.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 306 AM EST FRI JAN 15 2016
SURFACE LOW CENTER HAS REACHED SRN WISCONSIN EARLY THIS MORNING...
WITH THE ASSOCIATED WARM FRONT EXTENDING EASTWARD FROM THE LOW
CENTER THRU SRN LWR MICHIGAN. MODELS CONTINUE TO OVER-FORECAST
PRECIP ALONG AND NORTH OF THIS WARM FRONT. LATEST LOOK AT KAPX SHOWS
ONLY PATCHY LIGHT FREEZING DRIZZLE AND/OR FLURRIES LINGERING ACROSS
MANLY THE NRN HALF OF OUR CWA IN THE WAKE OF AN AREA OF LIGHT SNOW
THAT HAS PUSHED NORTH OF OUR CWA. A VERY LIGHT MIST/FREEZING DRIZZLE
IS FALLING HERE AT THE GAYLORD OFFICE...WHICH MAKES SENSE LOOKING AT
OUR MODEL SOUNDINGS FOR EARLY THIS MORNING. LOW LEVELS ARE SATURATED
THRU ABOUT 850 MB...WITH A THICK LAYER OF DRY AIR AT MID LEVELS...
AND THEN ADDITIONAL MOISTURE ABOVE 600 MB. LOW LEVEL MOISTURE COMES
NOWHERE NEAR THE -10 C ISOTHERM AND SURFACE TEMPS REMAIN WELL BELOW
FREEZING AT THIS HOUR...THUS THE PATCHY LIGHT FREEZING DRIZZLE.
BOTH THE LATEST RAP13 AND THE HRRR SHOW ONLY SMALL CHANCES OF LIGHT
PRECIP EARLY THIS MORNING ACROSS MOST OF OUR CWA THRU DAYBREAK...
WITH SOME INDICATION OF GRADUALLY INCREASING POPS AS WE HEAD THRU
THE DAY IN RESPONSE TO INCREASING LIFT AND MOISTURE NEAR THE SURFACE
LOW CENTER. HIGHEST POPS ACTUALLY DEVELOP ACROSS THE SE HALF OF OUR
CWA THIS AFTERNOON JUST AHEAD OF THE SURFACE LOW CENTER AS IT TRACKS
NE THRU NRN LWR MICHIGAN. MODEL SOUNDINGS STILL SUGGEST A RATHER
TIGHT LOW LEVEL THERMAL GRADIENT WILL SET UP ACROSS OUR SRN CWA
TODAY AS THE LOW TRACKS RIGHT OVERHEAD. BASED ON MODEL SOUNDINGS...
PRECIP SHOULD REMAIN ALL SNOW ACROSS ERN UPR MICHIGAN AND THE TIP OF
THE MITT...WITH A MIX OF RAIN/SNOW AND POSSIBLY SOME FREEZING RAIN
AND SLEET MIXING IN AT TIMES ALONG THE TIGHT TEMP GRADIENT. PRECIP
WILL LIKELY BECOME ALL RAIN FOR PORTIONS OF OUR SRN CWA AND
ESPECIALLY OUR SE CWA FROM ROGERS CITY TO HOUGHTON LAKE EASTWARD AS
THE WARMEST AIR SURGES NORTHWARD IN THE AFTERNOON WITHIN THIS AREA
JUST AHEAD OF THE SURFACE LOW CENTER. WITH HIGH TEMPS WARMING INTO
THE MID TO UPPER 30S ACROSS MOST OF NRN LWR MICHIGAN...DO NOT EXPECT
ANY SIGNIFICANT ICE ACCUMULATION...BUT WILL CERTAINLY KEEP A CLOSE
EYE ON PRECIP TYPE AND DURATION AS THIS EVENT UNFOLDS. PRIMARY
CHANGES TO THE FORECAST WILL BE TO DECREASE POPS...ESPECIALLY THIS
MORNING BASED ON NEAR TERM OBSERVED AND MODEL TRENDS. CAA KICKS IN
IN THE WAKE OF THE DEPARTING LOW TONIGHT...SWITCHING PRECIP TYPE
BACK OVER TO ALL SNOW. ALSO...OVER-LAKE INSTABILITY WILL AGAIN
INCREASE WITH ONGOING CAA...TARGETING NW FLOW AREAS FOR HIGHEST POPS
TONIGHT. NEW SNOW ACCUMULATIONS WILL BE A GENERAL 1 TO 3 INCHES
TODAY FOR OUR NRN CWA...WITH ANOTHER INCH OR SO TONIGHT.
&&
.SHORT TERM...(SATURDAY THROUGH SUNDAY NIGHT)
ISSUED AT 306 AM EST FRI JAN 15 2016
SATURDAY AND SUNDAY...COLD AND SNOWY WEATHER TO CONTINUE ACROSS THE
GREAT LAKES REGION THIS WEEKEND. A STORM SYSTEM OVER THE EASTERN
LAKES SATURDAY WILL EXIT NORTHEAST INTO QUEBEC SUNDAY...WHILE AN
UPPER LVL SYSTEM SETTLES INTO THE REGION. MODEL SOUNDINGS AND MSTR
PROGS SHOW MID LVL DRYING (700/500MB RH UNDER 50 PCT) SATURDAY
AFTERNOON AS THE SFC LOW LIFTS NORTHEAST INTO QUEBEC...DIMINISHING
SNOWFALL ACROSS NORTHEAST LOWER SATURDAY AFTERNOON AND EVENING.
HOWEVER LAKE EFFECT PARAMETERS WILL STRENGTHEN SATURDAY AFTERNOON
ACRS THE WRN LAKES...WITH 850MB TEMPS FALLING TO -16C WHILE LOW LVL
INVERSION HEIGHTS INCREASE TO 4K FEET. SFC-850MB WINDS WILL
TRANSITION FROM NORTHWEST TO WEST THROUGH SATURDAY AFTERNOON IN
DIMINISHING CYCLONIC FLOW ON THE BACKSIDE OF THE EXITING STORM
SYSTEM. OVERALL WILL DIMINISH POPS ACROSS NORTHEAST LOWER SATURDAY
MORNING AS DRY MID LVL AIR SETTLES OVER THE REGION...WITH AT LEAST
LIKELY POPS OVER THE WRN LAKES THROUGH SATURDAY EVENING DUE TO LAKE
EFFECTS
SIGNIFICANT SNOW IS POSSIBLE SUNDAY FOR PORTIONS OF NRN MI...THE
COMBINATION OF AN UPPER LOW DROPPING INTO THE GREAT LAKES AS MID LVL
MSTR INCREASES AND LAKE EFFECT PARAMETERS STRENGTHEN. 700/500MB RH
INCREASES TO GREATER THAN 90 PCT SUNDAY WHILE 850/500MB QVECTOR
CONVERGENCE SHOWS STRONG FORCING OVER NRN MI IN ADVANCE OF
APPROACHING UPPER LOW. MODEL SOUNDINGS CONTINUE TO SHOW LAKE
PARAMETERS IMPROVING THROUGH THE DAY SUNDAY AS 850MB TEMPS DROP TO
-24C...INVERSION HEIGHTS INCREASE TO NEARLY 9KT WITH ABUNDANCE MSTR
THROUGH THE COLUMN. LAKES BANDS WILL BE HIGHLY UNORGANIZED THROUGH
18Z SUNDAY AS SFC-850MB WINDS SHIFT FROM SOUTHWEST TO WEST BEFORE
FINALLY LOCKING IN NORTHWEST SUNDAY EVENING INTO MONDAY. OVERALL
WILL MENTION SNOW FOR THE ENTIRE CWA SUNDAY WITH LAKE ENHANCEMENTS
FORCING HIGHEST POPS OVER THE WRN LAKES.
HIGH TEMPERATURES THIS WEEKEND WILL FALL FROM NEAR SEASONAL READINGS
IN THE 20S SATURDAY TO BETWEEN 10 AND 15 DEGREES SUNDAY AS 850MB
TEMPS PLUNGE TO -24C IN DEEPENING UPPER TROUGH.
&&
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 306 AM EST FRI JAN 15 2016
MONDAY THROUGH THURSDAY...SURFACE AND UPPER LVL STORM SYSTEMS WILL
BE IN PLACE OVER THE GREAT LAKES TO BEGIN THE UPCOMING WORK
WEEK...BEFORE SLOWLY EXITING EAST OF THE REGION TUESDAY. THIS
PATTERN WILL GENERATE SNOW ACROSS MUCH OF NORTHERN MICHIGAN MONDAY
WITH LAKE EFFECT SNOW OVER THE WRN LAKES TUESDAY...DUE TO LINGERING
CYCLONIC FLOW ON THE BACK SIDE OF THE EXITING STORM SYSTEM (NW WINDS
SFC-850MB WITH INVERSION HEIGHTS TO 6K FT). TEMPERATURES WILL BE
BELOW NORMAL THROUGH TUESDAY AS 850MB TEMPS IN THE BASE OF THE 500MB
TROUGH DROP TO -24C...FORCING DAYTIME HIGHS TO REMAIN IN THE TEENS
WITH LOWS IN THE SINGLE DIGITS.
WEDNESDAY AND THURSDAY ARE CURRENTLY TRENDING LESS ACTIVE WHEN
COMPARED TO THE PAST WEEK. A LARGE AREA OF HIGH PRESSURE AND DRY AIR
WILL SETTLE OVER THE ENTIRE GREAT LAKES AND OHIO VALLEY BY MID
WEEK...WHILE 500MB HEIGHTS INCREASE ACROSS THE UPPER MIDWEST. ANY
LAKE INFLUENCES WEDNESDAY AND THURSDAY WILL BE HINDERED BY LACK OF
OVER WATER INSTABILITY WITH 850MB TEMPS WARMING TO -8C THURSDAY. THE
WARMING IN MID LVLS WILL HELP DAYTIME TEMPS TREND CLOSER TO MID
JANUARY SEASONAL LEVELS IN THE LOWER 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 600 AM EST FRI JAN 15 2016
PATCHY FREEZING DRIZZLE WILL CONTINUE TO IMPACT NRN LWR MICHIGAN
THIS MORNING BEFORE BETTER CHANCES OF MEASURABLE PRECIP DEVELOPS
THIS AFTERNOON AND TONIGHT. A MIX OF RAIN AND/OR SNOW IS POSSIBLE
THIS AFTERNOON AHEAD OF LOW PRESSURE TRACKING DIRECTLY OVER NRN
LWR MICHIGAN. THE BEST CHANCE OF MIXED PRECIP WILL BE AROUND
APN...TVC AND MBL. PLN WILL LIKELY REMAIN ALL SNOW JUST NORTH OF
THE TRACK OF THE SURFACE LOW. OVERALL PRECIP INTENSITY WILL REMAIN
LIGHT ACROSS THE ENTIRE REGION. ALL PRECIP WILL AGAIN BECOME ALL
SNOW BY LATE EVENING AS CAA COMMENCES IN THE WAKE OF THE DEPARTING
LOW. CONDITIONS WILL REMAIN IFR TO LOW MVFR THRU THE ENTIRE TAF
FORECAST PERIOD. EAST WIND AROUND 10 KTS TODAY WILL SHIFT TO THE
N/NW BEHIND THE LOW TONIGHT WITH GUSTS TO 20 KTS EXPECTED.
&&
.MARINE...
ISSUED AT 306 AM EST FRI JAN 15 2016
WINDS AND WAVES WILL REMAIN JUST AT SCA CRITERIA THRU MUCH OF TODAY
FOR OUR NRN NEARSHORE AREAS JUST NORTH OF THE SURFACE LOW CENTER
TRACK. MAINLY SNOW IS EXPECTED WITHIN THESE AREAS...WITH A WINTRY
MIX OF PRECIP EXPECTED FOR OUR NEARSHORE AREAS SOUTH OF THE ADVISORY
AREAS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
LHZ345>348.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR LMZ341-
342.
LS...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR LSZ321-
322.
&&
$$
UPDATE...FARINA
NEAR TERM...MLR
SHORT TERM...SWR
LONG TERM...SWR
AVIATION...MLR
MARINE...MLR
AREA FORECAST DISCUSSION
NWS GAYLORD MI
600 AM EST FRI JAN 15 2016
.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 306 AM EST FRI JAN 15 2016
SURFACE LOW CENTER HAS REACHED SRN WISCONSIN EARLY THIS MORNING...
WITH THE ASSOCIATED WARM FRONT EXTENDING EASTWARD FROM THE LOW
CENTER THRU SRN LWR MICHIGAN. MODELS CONTINUE TO OVER-FORECAST
PRECIP ALONG AND NORTH OF THIS WARM FRONT. LATEST LOOK AT KAPX SHOWS
ONLY PATCHY LIGHT FREEZING DRIZZLE AND/OR FLURRIES LINGERING ACROSS
MANLY THE NRN HALF OF OUR CWA IN THE WAKE OF AN AREA OF LIGHT SNOW
THAT HAS PUSHED NORTH OF OUR CWA. A VERY LIGHT MIST/FREEZING DRIZZLE
IS FALLING HERE AT THE GAYLORD OFFICE...WHICH MAKES SENSE LOOKING AT
OUR MODEL SOUNDINGS FOR EARLY THIS MORNING. LOW LEVELS ARE SATURATED
THRU ABOUT 850 MB...WITH A THICK LAYER OF DRY AIR AT MID LEVELS...
AND THEN ADDITIONAL MOISTURE ABOVE 600 MB. LOW LEVEL MOISTURE COMES
NOWHERE NEAR THE -10 C ISOTHERM AND SURFACE TEMPS REMAIN WELL BELOW
FREEZING AT THIS HOUR...THUS THE PATCHY LIGHT FREEZING DRIZZLE.
BOTH THE LATEST RAP13 AND THE HRRR SHOW ONLY SMALL CHANCES OF LIGHT
PRECIP EARLY THIS MORNING ACROSS MOST OF OUR CWA THRU DAYBREAK...
WITH SOME INDICATION OF GRADUALLY INCREASING POPS AS WE HEAD THRU
THE DAY IN RESPONSE TO INCREASING LIFT AND MOISTURE NEAR THE SURFACE
LOW CENTER. HIGHEST POPS ACTUALLY DEVELOP ACROSS THE SE HALF OF OUR
CWA THIS AFTERNOON JUST AHEAD OF THE SURFACE LOW CENTER AS IT TRACKS
NE THRU NRN LWR MICHIGAN. MODEL SOUNDINGS STILL SUGGEST A RATHER
TIGHT LOW LEVEL THERMAL GRADIENT WILL SET UP ACROSS OUR SRN CWA
TODAY AS THE LOW TRACKS RIGHT OVERHEAD. BASED ON MODEL SOUNDINGS...
PRECIP SHOULD REMAIN ALL SNOW ACROSS ERN UPR MICHIGAN AND THE TIP OF
THE MITT...WITH A MIX OF RAIN/SNOW AND POSSIBLY SOME FREEZING RAIN
AND SLEET MIXING IN AT TIMES ALONG THE TIGHT TEMP GRADIENT. PRECIP
WILL LIKELY BECOME ALL RAIN FOR PORTIONS OF OUR SRN CWA AND
ESPECIALLY OUR SE CWA FROM ROGERS CITY TO HOUGHTON LAKE EASTWARD AS
THE WARMEST AIR SURGES NORTHWARD IN THE AFTERNOON WITHIN THIS AREA
JUST AHEAD OF THE SURFACE LOW CENTER. WITH HIGH TEMPS WARMING INTO
THE MID TO UPPER 30S ACROSS MOST OF NRN LWR MICHIGAN...DO NOT EXPECT
ANY SIGNIFICANT ICE ACCUMULATION...BUT WILL CERTAINLY KEEP A CLOSE
EYE ON PRECIP TYPE AND DURATION AS THIS EVENT UNFOLDS. PRIMARY
CHANGES TO THE FORECAST WILL BE TO DECREASE POPS...ESPECIALLY THIS
MORNING BASED ON NEAR TERM OBSERVED AND MODEL TRENDS. CAA KICKS IN
IN THE WAKE OF THE DEPARTING LOW TONIGHT...SWITCHING PRECIP TYPE
BACK OVER TO ALL SNOW. ALSO...OVER-LAKE INSTABILITY WILL AGAIN
INCREASE WITH ONGOING CAA...TARGETING NW FLOW AREAS FOR HIGHEST POPS
TONIGHT. NEW SNOW ACCUMULATIONS WILL BE A GENERAL 1 TO 3 INCHES
TODAY FOR OUR NRN CWA...WITH ANOTHER INCH OR SO TONIGHT.
&&
.SHORT TERM...(SATURDAY THROUGH SUNDAY NIGHT)
ISSUED AT 306 AM EST FRI JAN 15 2016
SATURDAY AND SUNDAY...COLD AND SNOWY WEATHER TO CONTINUE ACROSS THE
GREAT LAKES REGION THIS WEEKEND. A STORM SYSTEM OVER THE EASTERN
LAKES SATURDAY WILL EXIT NORTHEAST INTO QUEBEC SUNDAY...WHILE AN
UPPER LVL SYSTEM SETTLES INTO THE REGION. MODEL SOUNDINGS AND MSTR
PROGS SHOW MID LVL DRYING (700/500MB RH UNDER 50 PCT) SATURDAY
AFTERNOON AS THE SFC LOW LIFTS NORTHEAST INTO QUEBEC...DIMINISHING
SNOWFALL ACROSS NORTHEAST LOWER SATURDAY AFTERNOON AND EVENING.
HOWEVER LAKE EFFECT PARAMETERS WILL STRENGTHEN SATURDAY AFTERNOON
ACRS THE WRN LAKES...WITH 850MB TEMPS FALLING TO -16C WHILE LOW LVL
INVERSION HEIGHTS INCREASE TO 4K FEET. SFC-850MB WINDS WILL
TRANSITION FROM NORTHWEST TO WEST THROUGH SATURDAY AFTERNOON IN
DIMINISHING CYCLONIC FLOW ON THE BACKSIDE OF THE EXITING STORM
SYSTEM. OVERALL WILL DIMINISH POPS ACROSS NORTHEAST LOWER SATURDAY
MORNING AS DRY MID LVL AIR SETTLES OVER THE REGION...WITH AT LEAST
LIKELY POPS OVER THE WRN LAKES THROUGH SATURDAY EVENING DUE TO LAKE
EFFECTS
SIGNIFICANT SNOW IS POSSIBLE SUNDAY FOR PORTIONS OF NRN MI...THE
COMBINATION OF AN UPPER LOW DROPPING INTO THE GREAT LAKES AS MID LVL
MSTR INCREASES AND LAKE EFFECT PARAMETERS STRENGTHEN. 700/500MB RH
INCREASES TO GREATER THAN 90 PCT SUNDAY WHILE 850/500MB QVECTOR
CONVERGENCE SHOWS STRONG FORCING OVER NRN MI IN ADVANCE OF
APPROACHING UPPER LOW. MODEL SOUNDINGS CONTINUE TO SHOW LAKE
PARAMETERS IMPROVING THROUGH THE DAY SUNDAY AS 850MB TEMPS DROP TO
-24C...INVERSION HEIGHTS INCREASE TO NEARLY 9KT WITH ABUNDANCE MSTR
THROUGH THE COLUMN. LAKES BANDS WILL BE HIGHLY UNORGANIZED THROUGH
18Z SUNDAY AS SFC-850MB WINDS SHIFT FROM SOUTHWEST TO WEST BEFORE
FINALLY LOCKING IN NORTHWEST SUNDAY EVENING INTO MONDAY. OVERALL
WILL MENTION SNOW FOR THE ENTIRE CWA SUNDAY WITH LAKE ENHANCEMENTS
FORCING HIGHEST POPS OVER THE WRN LAKES.
HIGH TEMPERATURES THIS WEEKEND WILL FALL FROM NEAR SEASONAL READINGS
IN THE 20S SATURDAY TO BETWEEN 10 AND 15 DEGREES SUNDAY AS 850MB
TEMPS PLUNGE TO -24C IN DEEPENING UPPER TROUGH.
&&
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 306 AM EST FRI JAN 15 2016
MONDAY THROUGH THURSDAY...SURFACE AND UPPER LVL STORM SYSTEMS WILL
BE IN PLACE OVER THE GREAT LAKES TO BEGIN THE UPCOMING WORK
WEEK...BEFORE SLOWLY EXITING EAST OF THE REGION TUESDAY. THIS
PATTERN WILL GENERATE SNOW ACROSS MUCH OF NORTHERN MICHIGAN MONDAY
WITH LAKE EFFECT SNOW OVER THE WRN LAKES TUESDAY...DUE TO LINGERING
CYCLONIC FLOW ON THE BACK SIDE OF THE EXITING STORM SYSTEM (NW WINDS
SFC-850MB WITH INVERSION HEIGHTS TO 6K FT). TEMPERATURES WILL BE
BELOW NORMAL THROUGH TUESDAY AS 850MB TEMPS IN THE BASE OF THE 500MB
TROUGH DROP TO -24C...FORCING DAYTIME HIGHS TO REMAIN IN THE TEENS
WITH LOWS IN THE SINGLE DIGITS.
WEDNESDAY AND THURSDAY ARE CURRENTLY TRENDING LESS ACTIVE WHEN
COMPARED TO THE PAST WEEK. A LARGE AREA OF HIGH PRESSURE AND DRY AIR
WILL SETTLE OVER THE ENTIRE GREAT LAKES AND OHIO VALLEY BY MID
WEEK...WHILE 500MB HEIGHTS INCREASE ACROSS THE UPPER MIDWEST. ANY
LAKE INFLUENCES WEDNESDAY AND THURSDAY WILL BE HINDERED BY LACK OF
OVER WATER INSTABILITY WITH 850MB TEMPS WARMING TO -8C THURSDAY. THE
WARMING IN MID LVLS WILL HELP DAYTIME TEMPS TREND CLOSER TO MID
JANUARY SEASONAL LEVELS IN THE LOWER 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 600 AM EST FRI JAN 15 2016
PATCHY FREEZING DRIZZLE WILL CONTINUE TO IMPACT NRN LWR MICHIGAN
THIS MORNING BEFORE BETTER CHANCES OF MEASURABLE PRECIP DEVELOPS
THIS AFTERNOON AND TONIGHT. A MIX OF RAIN AND/OR SNOW IS POSSIBLE
THIS AFTERNOON AHEAD OF LOW PRESSURE TRACKING DIRECTLY OVER NRN
LWR MICHIGAN. THE BEST CHANCE OF MIXED PRECIP WILL BE AROUND
APN...TVC AND MBL. PLN WILL LIKELY REMAIN ALL SNOW JUST NORTH OF
THE TRACK OF THE SURFACE LOW. OVERALL PRECIP INTENSITY WILL REMAIN
LIGHT ACROSS THE ENTIRE REGION. ALL PRECIP WILL AGAIN BECOME ALL
SNOW BY LATE EVENING AS CAA COMMENCES IN THE WAKE OF THE DEPARTING
LOW. CONDITIONS WILL REMAIN IFR TO LOW MVFR THRU THE ENTIRE TAF
FORECAST PERIOD. EAST WIND AROUND 10 KTS TODAY WILL SHIFT TO THE
N/NW BEHIND THE LOW TONIGHT WITH GUSTS TO 20 KTS EXPECTED.
&&
.MARINE...
ISSUED AT 306 AM EST FRI JAN 15 2016
WINDS AND WAVES WILL REMAIN JUST AT SCA CRITERIA THRU MUCH OF TODAY
FOR OUR NRN NEARSHORE AREAS JUST NORTH OF THE SURFACE LOW CENTER
TRACK. MAINLY SNOW IS EXPECTED WITHIN THESE AREAS...WITH A WINTRY
MIX OF PRECIP EXPECTED FOR OUR NEARSHORE AREAS SOUTH OF THE ADVISORY
AREAS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
LHZ345>348.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR LMZ341-
342.
LS...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR LSZ321-
322.
&&
$$
NEAR TERM...MLR
SHORT TERM...SWR
LONG TERM...SWR
AVIATION...MLR
MARINE...MLR
AREA FORECAST DISCUSSION
NWS GLASGOW MT
326 AM MST FRI JAN 15 2016
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
FORECAST CHALLENGES IN THE SHORT TERM PERIOD WILL FOCUS ON
TEMPERATURES AND THE EXTENT OF THE SCATTERED SNOW
SHOWERS...ESPECIALLY FOR THE SW HALF OF OUR CWA TODAY...THEN COLD
WIND CHILLS LATER THROUGH THE WEEKEND.
CURRENT WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWS A
GENERAL NW FLOW ALOFT WITH LIMITED MOISTURE RESULTING IN SOME
SCATTERED SNOW SHOWERS PRIMARILY OVER OUR WESTERN ZONES. IT SEEMS
THAT THE MORE AGRESSIVE MODEL DEPICTIONS OF PRECIP...SUCH AS THE
NAM AND GFS...HAVE PROVEN TOO AGRESSIVE OVERNIGHT. LIGHTER
AMOUNTS FROM THE HRRR MODEL ARE MORE REPRESENTATIVE OF ACTUAL AREA
REFLECTIVITIES. WOULD EXPECT NEW SNOWFALL TOTALS TO BE CLOSER TO
AROUND 1 INCH THAN 2 INCHES.
WITH THE ARRIVAL OF THE ARCTIC AIR MASS ON SATURDAY...SCATTERED
SNOW SHOWERS AND FLURRIES WILL BE CLEARED OUT AND REPLACED BY A
MORE CERTAIN WEATHER PATTERN OF CLEARING SKIES AND MUCH COLDER
TEMPERATURES OVER OUR CENTRAL AND NE ZONES AND A BAND
ACCUMULATING SNOW OVER OUR SW ZONES.
SATURDAY NIGHT...WIND CHILL CONCERNS WILL ARISE WITH THE COLDEST
TEMPERATURES AND WINDS AROUND 10 MPH POSSIBLE ESPECIALLY FOR OUR
NE CWA ZONES EXPECTED TO BRING WIND CHILL VALUES BETWEEN 25 AND 40
DEGREES BELOW ZERO. NOT YET CONFIDENT OR CLOSE ENOUGH TO GO WITH
ANY WIND CHILL HEADLINE PRODUCTS BUT NEXT FEW SHIFTS WILL NEED TO
SERIOUSLY CONSIDER THE NEED IF TEMPERATURE AND WIND MODEL TRENDS
CONTINUE IN THIS WAY. BMICKELSON
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
EXTENDED PERIOD OPENS NEXT WEEK WITH AN ARCTIC LOW OVER THE
NORTHERN GREAT LAKES AND UPPER RIDGE PUSHING THROUGH THE NORTHERN
ROCKIES.. ARCTIC HIGH MOVING OUT OF THE NORTHERN PLAINS WILL HAVE
LEFT BEHIND A COLD AIR MASS ACROSS MOST OF NORTHEAST MONTANA FOR
MONDAY. AS A SHORTWAVE PUSHES THROUGH THE RIDGE AND ACROSS THE
NORTHERN ROCKIES ON MONDAY...MOISTURE WILL SPREAD OVER THE COLD
AIR MASS...BRINGING LIGHT SNOW INTO EASTERN MONTANA.
REMAINDER OF THE WEEK FEATURES MORE UNCERTAINTY WITH A SERIES OF
PACIFIC OR ARCTIC SHORTWAVES DEPENDING ON THE MODEL SOLUTION.
MODELS TRENDING TOWARD WARMING ALOFT BY THE END OF THE WEEK BUT
GIVEN THE PERSISTENCE OF THE COLD AIR MASS OVER THE REGION WILL
KEEP TEMPERATURES BELOW CLIMO FOR MOST OF THE PERIOD. EBERT
&&
.AVIATION...
MVFR CEILINGS EXPECTED TO LINGER THROUGH TODAY. VISIBILITY
REDUCTIONS ARE ALSO POSSIBLE WITH FOG OR SNOW SHOWERS THROUGH THE
DAY.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1025 AM EST FRI JAN 15 2016
.SYNOPSIS...A DEVELOPING LOW PRESSURE SYSTEM WILL TRACK FROM THE
GULF COAST AND UP THE SOUTHEAST AND NC COAST THROUGH
TONIGHT. A DRY COLD FRONT WILL CROSS THE AREA ON SATURDAY.
AN UPPER DISTURBANCE WILL CROSS THE AREA EARLY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM FRIDAY...
A SOUTHERN STREAM SHORTWAVE IN SOUTHWESTERLY FLOW ALOFT AND ITS
ASSOCIATED 1002MB...BUT DEEPENING... SURFACE LOW WILL TRACK
NORTHEAST ACROSS THE AREA TODAY. STRONG FORCING FOR ASCENT...DCVA
AND WARM ADVECTION...WILL OVERSPREAD THE AREA THROUGH THIS
AFTERNOON...WITH WIDESPREAD RAINFALL ALREADY ON THE DOORSTEP OF THE
SOUTHERN PIEDMONT AS OF 10AM. MODELS ARE FINALLY CONVERGING ON THE
SURFACE LOW TRACK BEING THROUGH THE COASTAL PLAIN THIS EVENING...OR
MORE SPECIFICALLY CLIPPING SAMPSON COUNTY AROUND 00Z. MODELS
INDICATE SOME VERY WEAK MUCAPE IN THE COASTAL PLAIN WITH THE INLAND
PENETRATION OF THE WARM FRONT LATE THIS AFTERNOON...BUT IT IS STILL
MOSTLY ELEVATED AND THE SEVERE THREAT STILL LOOKS TO BE CONFINED TO
THE COAST DESPITE SUFFICIENT SHEAR THROUGHOUT THE COLUMN. HALF AN
INCH TO AN INCH OF QPF STILL IS STILL EXPECTED...BUT THERE IS SOME
UNCERTAINTY IN THE DISTRIBUTION. HIGH RES GUIDANCE SEEMS TO BE
LATCHING ONTO A TREND THE GFS HAS BEEN SHOWING WITH HEAVIER AMOUNTS
AROUND AN INCH IN THE WESTERN PIEDMONT (IN CLOSER PROXIMITY TO THE
TRACK OF THE MID-LEVEL LOW AND NORTHERN STREAM WAVE PASSING TO OUT
NORTHWEST) AND ALSO EAST OF I-95 (NEAR AND EAST OF THE SURFACE LOW).
ADD IN A POSSIBLE GRAVITY WAVE NOTED IN SURFACE OBS IN SOUTHWEST
GEORGIA THIS MORNING...WHICH MAY BE A PART OF WHY THE HRRR SHOWS A
RAPID SPLIT IF QPF WITH NORTHERN EXTENT THIS AFTERNOON. HIGHS WILL
RANGE FROM MID 40S NW TO MID 50S SE.
CLOUDS WILL GIVE WAY TO CLEARING LATE TONIGHT/SATURDAY
MORNING WITH LOWS IN THE MID 30S NORTHWEST TO LOWER 40S SE.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 255 AM FRIDAY...
SATURDAY: AS THE INLAND LOW OVER THE EASTERN GREAT LAKES MOVES INTO
THE SOUTHEAST CANADA...IT WILL DRAG A DRY COLD FRONT THROUGH THE
AREA SATURDAY AFTERNOON/EVENING. LATE ONSET OF CAA WILL RESULT IN
MILDISH TEMPERATURES ACROSS CENTRAL ON SATURDAY RANGING FROM LOWER
50S NW PIEDMONT TO UPPER 50S ACROSS THE SOUTHEAST.
SATURDAY NIGHT: THE CLOSED UPPER LEVEL LOW THAT TRACKED INLAND OVER
THE PACIFIC NORTHWEST LAST NIGHT WILL CONTINUE TO DEVOLVE INTO AN
OPEN WAVE AS IT DROPS SOUTHEAST ACROSS THE SOUTHERN ROCKIES TONIGHT
AND THEN OVER THE SOUTHERN PLAINS AND INTO CENTRAL GULF COAST REGION
BY SATURDAY NIGHT. MODELS HAVE COME INTO BETTER AGREEMENT WITH A
SUPPRESSED SOUTHERN STREAM SURFACE CYCLOGENESIS OVER THE GULF/DEEP
SOUTH WITH LITTLE TO PRECIP EXPECTED FROM THIS SYSTEM.
INSTEAD...CENTRAL NC COULD SEE SOME VERY LIGHT PRECIP ACROSS THE
AREA LATE SATURDAY NIGHT/SUNDAY MORNING AS NORTHERN STREAM SHORTWAVE
APPROACHES THE AREA FROM THE WEST. GIVEN FAVORABLE NOCTURNAL TIMING
AND MODEST CAA FROM EARLIER COLD FRONTAL PASSAGE SATURDAY
AFTERNOON...COULD SEE A BRIEF PERIOD OF LIGHT RAIN AND POSSIBLY EVEN
LIGHT RAIN OR SNOW ACROSS THE FAR NW PIEDMONT WHERE MODELS SHOW
SURFACE WET-BULBS AROUND FREEZING. AT THIS TIME PRECIP AMOUNTS ARE
TOO LIGHT AND TEMPERATURE PROFILES ARE MARGINALLY COLD ENOUGH TO
SUPPORT MUCH MORE THAN A "GEE WHIZ" SIGHTING OF SNOW. LOWS IN THE
LOWER 30S NW PIEDMONT TO UPPER 30S SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE MEDIUM RANGE MODELS ARE COMING INTO
BETTER AGREEMENT ON HOW THEY HANDLE THE INTERACTION BETWEEN THE
UPPER LEVEL NORTHERN STREAM SHORTWAVE TROUGH MOVING ACROSS THE OH/TN
VALLEY AND INTO THE MID ATLANTIC AND A SOUTHERN STREAM LOW THAT
DEVELOPS OVER THE GULF OF MEXICO. BOTH THE ECMWF AND GFS BRING THE
SOUTHERN STREAM LOW ACROSS THE GULF COAST STATES AND OFF THE SE U.S.
ATLANTIC COAST SUNDAY...KEEPING THE PRECIPITATION...ALL LIQUID...
ALONG AND EAST OF US-1. THE SHORTWAVE HOWEVER MAY GENERATE ITS OWN
PRECIPITATION...WHICH COULD BE NON-LIQUID OR A RAIN/SNOW MIX. THE
PRECIP...REGARDLESS OF TYPE...WILL LIKELY ALL OCCUR BETWEEN 09Z AND
15Z SUNDAY...WITH SOME RAIN LINGERING ACROSS THE FAR EAST INTO THE
EARLY AFTERNOON...AND RESULT IN LITTLE ACCUMULATION. DO NOT EXPECT
ANY SIGNIFICANT IMPACTS AT THIS TIME. HIGHS IN THE MID 40S EXPECTED.
THE COLD SURFACE HIGH WILL START BUILDING INTO THE REGION SUNDAY
NIGHT...WITH CLEARING SKIES BUT WINDS STAYING UP AROUND 5 MPH. AS A
RESULT...LOWS WILL BE COOLER THAN PREVIOUS NIGHTS...LOW 20S NW TO
UPPER 20S SE...FEELING MORE LIKE MID TEENS NW TO MID 20S SE AROUND
DAYBREAK MONDAY.
MONDAY AND TUESDAY: THIS PERIOD IS EXPECTED TO BE COLD AND DRY AS
CANADIAN HIGH PRESSURE BUILDS IN AT THE SURFACE. AS THE UPPER LEVEL
TROUGH PROGRESSES THROUGH THE REGION THE FLOW ALOFT WILL GRADUALLY
BECOME MORE NWRLY. HIGHS MON AND TUE WILL BE FAIRLY STEADY ACROSS
THE NORTH...LOW TO MID 30S...WITH MID 30S TO AROUND 40 DEGREES SOUTH.
LOWS SHOULD BOTTOM OUT MON NIGHT...MID TEENS NW TO LOW 20S SE...
INCREASING A FEW DEGREES TUE NIGHT...LOW TO MID 20S. CURRENT
APPARENT TEMPERATURES TUESDAY MORNING RANGE FROM 10 DEGREES NW TO
MID TEENS SE.
WEDNESDAY AND THURSDAY: TEMPS WILL MODERATE WED AND THU...WITH HIGHS
BACK INTO THE 40S AND LOWS INCREASING FROM THE MID TO UPPER 20S WED
NIGHT TO UPPER 20S TO LOW 30S THU NIGHT. SIGNIFICANT DIFFERENCES IN
THE MEDIUM RANGE MODELS FOR MID TO LATE WEEK YIELD LOW FORECAST
CONFIDENCE...BUT FOR NOW THE FORECAST APPEARS TO BE DRY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 705 AM FRIDAY...
24 HOUR TAF PERIOD: VFR CONDITIONS THIS WILL GIVE WAY TO WIDESPREAD
IFR TO LIFR CONDITIONS IN RAIN THIS AFTERNOON AND EVENING.
A DEVELOPING AREA OF LOW PRESSURE ALONG THE NORTHERN GULF OF MEXICO
WILL TRACK NEWD THROUGH THE SOUTHEAST TODAY AND THEN ACROSS NORTH
CAROLINA THIS EVENING...BEFORE MOVING UP THE MID-ATLANTIC ON
SATURDAY.
RAIN WILL SPREAD SW TO NE INTO THE AREA LATE THIS MORNING THROUGH
THE EVENING WITH CEILINGS DETERIORATING TO IFR AND POSSIBLY LIFR INTO.
RAIN WILL BE MODERATE TO HEAVY AT TIMES...SO EXPECT SIGNIFICANT
REDUCTION IN VISIBILITIES AS WELL. RAIN SHOULD TAPER OFF FROM SW TO
NE BETWEEN 00Z TO 06Z...WITH VFR CONDITIONS RETURNING SATURDAY
MORNING.
OUTLOOK: AN UPPER LEVEL DISTURBANCE MOVING THROUGH THE AREA LATE
SATURDAY/SUNDAY MORNING COULD BRING SOME MVFR CEILINGS ACROSS THE
AREA ALONG WITH A BRIEF PERIOD OF RAIN/SNOW MIX. VFR CONDITIONS WILL
THEN DOMINATE EARLY TO MID NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL/22
SHORT TERM...CBL
LONG TERM...KC
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
5 AM EST FRI JAN 15 2016
.SYNOPSIS...A DEVELOPING LOW PRESSURE SYSTEM WILL TRACK FROM THE
GULF COAST AND UP THE SOUTHEAST AND NC COAST THROUGH
TONIGHT. A DRY COLD FRONT WILL CROSS THE AREA ON SATURDAY.
AN UPPER DISTURBANCE WILL CROSS THE AREA EARLY SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM FRIDAY...
A SOUTHERN STREAM SHORTWAVE IN SOUTHWESTERLY FLOW ALOFT AND ITS
ASSOCIATED 1002MB...BUT DEEPENING... SURFACE LOW WILL TRACK
NORTHEAST ACROSS THE AREA TODAY. STRONG FORCING FOR ASCENT...DCVA
AND WARM ADVECTION...WILL OVERSPREAD THE AREA THROUGH THIS
AFTERNOON...WITH WIDESPREAD RAINFALL ALREADY ON THE DOORSTEP OF THE
SOUTHERN PIEDMONT AS OF 10AM. MODELS ARE FINALLY CONVERGING ON THE
SURFACE LOW TRACK BEING THROUGH THE COASTAL PLAIN THIS EVENING...OR
MORE SPECIFICALLY CLIPPING SAMPSON COUNTY AROUND 00Z. MODELS
INDICATE SOME VERY WEAK MUCAPE IN THE COASTAL PLAIN WITH THE INLAND
PENETRATION OF THE WARM FRONT LATE THIS AFTERNOON...BUT IT IS STILL
MOSTLY ELEVATED AND THE SEVERE THREAT STILL LOOKS TO BE CONFINED TO
THE COAST DESPITE SUFFICIENT SHEAR THROUGHOUT THE COLUMN. HALF AN
INCH TO AN INCH OF QPF STILL IS STILL EXPECTED...BUT THERE IS SOME
UNCERTAINTY IN THE DISTRIBUTION. HIGH RES GUIDANCE SEEMS TO BE
LATCHING ONTO A TREND THE GFS HAS BEEN SHOWING WITH HEAVIER AMOUNTS
AROUND AN INCH IN THE WESTERN PIEDMONT (IN CLOSER PROXIMITY TO THE
TRACK OF THE MID-LEVEL LOW AND NORTHERN STREAM WAVE PASSING TO OUT
NORTHWEST) AND ALSO EAST OF I-95 (NEAR AND EAST OF THE SURFACE LOW).
ADD IN A POSSIBLE GRAVITY WAVE NOTED IN SURFACE OBS IN SOUTHWEST
GEORGIA THIS MORNING...WHICH MAY BE A PART OF WHY THE HRRR SHOWS A
RAPID SPLIT IF QPF WITH NORTHERN EXTENT THIS AFTERNOON. HIGHS WILL
RANGE FROM MID 40S NW TO MID 50S SE.
CLOUDS WILL GIVE WAY TO CLEARING LATE TONIGHT/SATURDAY
MORNING WITH LOWS IN THE MID 30S NORTHWEST TO LOWER 40S SE.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 255 AM FRIDAY...
SATURDAY: AS THE INLAND LOW OVER THE EASTERN GREAT LAKES MOVES INTO
THE SOUTHEAST CANADA...IT WILL DRAG A DRY COLD FRONT THROUGH THE
AREA SATURDAY AFTERNOON/EVENING. LATE ONSET OF CAA WILL RESULT IN
MILDISH TEMPERATURES ACROSS CENTRAL ON SATURDAY RANGING FROM LOWER
50S NW PIEDMONT TO UPPER 50S ACROSS THE SOUTHEAST.
SATURDAY NIGHT: THE CLOSED UPPER LEVEL LOW THAT TRACKED INLAND OVER
THE PACIFIC NORTHWEST LAST NIGHT WILL CONTINUE TO DEVOLVE INTO AN
OPEN WAVE AS IT DROPS SOUTHEAST ACROSS THE SOUTHERN ROCKIES TONIGHT
AND THEN OVER THE SOUTHERN PLAINS AND INTO CENTRAL GULF COAST REGION
BY SATURDAY NIGHT. MODELS HAVE COME INTO BETTER AGREEMENT WITH A
SUPPRESSED SOUTHERN STREAM SURFACE CYCLOGENESIS OVER THE GULF/DEEP
SOUTH WITH LITTLE TO PRECIP EXPECTED FROM THIS SYSTEM.
INSTEAD...CENTRAL NC COULD SEE SOME VERY LIGHT PRECIP ACROSS THE
AREA LATE SATURDAY NIGHT/SUNDAY MORNING AS NORTHERN STREAM SHORTWAVE
APPROACHES THE AREA FROM THE WEST. GIVEN FAVORABLE NOCTURNAL TIMING
AND MODEST CAA FROM EARLIER COLD FRONTAL PASSAGE SATURDAY
AFTERNOON...COULD SEE A BRIEF PERIOD OF LIGHT RAIN AND POSSIBLY EVEN
LIGHT RAIN OR SNOW ACROSS THE FAR NW PIEDMONT WHERE MODELS SHOW
SURFACE WET-BULBS AROUND FREEZING. AT THIS TIME PRECIP AMOUNTS ARE
TOO LIGHT AND TEMPERATURE PROFILES ARE MARGINALLY COLD ENOUGH TO
SUPPORT MUCH MORE THAN A "GEE WHIZ" SIGHTING OF SNOW. LOWS IN THE
LOWER 30S NW PIEDMONT TO UPPER 30S SOUTHEAST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...
SUNDAY AND SUNDAY NIGHT: THE MEDIUM RANGE MODELS ARE COMING INTO
BETTER AGREEMENT ON HOW THEY HANDLE THE INTERACTION BETWEEN THE
UPPER LEVEL NORTHERN STREAM SHORTWAVE TROUGH MOVING ACROSS THE OH/TN
VALLEY AND INTO THE MID ATLANTIC AND A SOUTHERN STREAM LOW THAT
DEVELOPS OVER THE GULF OF MEXICO. BOTH THE ECMWF AND GFS BRING THE
SOUTHERN STREAM LOW ACROSS THE GULF COAST STATES AND OFF THE SE U.S.
ATLANTIC COAST SUNDAY...KEEPING THE PRECIPITATION...ALL LIQUID...
ALONG AND EAST OF US-1. THE SHORTWAVE HOWEVER MAY GENERATE ITS OWN
PRECIPITATION...WHICH COULD BE NON-LIQUID OR A RAIN/SNOW MIX. THE
PRECIP...REGARDLESS OF TYPE...WILL LIKELY ALL OCCUR BETWEEN 09Z AND
15Z SUNDAY...WITH SOME RAIN LINGERING ACROSS THE FAR EAST INTO THE
EARLY AFTERNOON...AND RESULT IN LITTLE ACCUMULATION. DO NOT EXPECT
ANY SIGNIFICANT IMPACTS AT THIS TIME. HIGHS IN THE MID 40S EXPECTED.
THE COLD SURFACE HIGH WILL START BUILDING INTO THE REGION SUNDAY
NIGHT...WITH CLEARING SKIES BUT WINDS STAYING UP AROUND 5 MPH. AS A
RESULT...LOWS WILL BE COOLER THAN PREVIOUS NIGHTS...LOW 20S NW TO
UPPER 20S SE...FEELING MORE LIKE MID TEENS NW TO MID 20S SE AROUND
DAYBREAK MONDAY.
MONDAY AND TUESDAY: THIS PERIOD IS EXPECTED TO BE COLD AND DRY AS
CANADIAN HIGH PRESSURE BUILDS IN AT THE SURFACE. AS THE UPPER LEVEL
TROUGH PROGRESSES THROUGH THE REGION THE FLOW ALOFT WILL GRADUALLY
BECOME MORE NWRLY. HIGHS MON AND TUE WILL BE FAIRLY STEADY ACROSS
THE NORTH...LOW TO MID 30S...WITH MID 30S TO AROUND 40 DEGREES SOUTH.
LOWS SHOULD BOTTOM OUT MON NIGHT...MID TEENS NW TO LOW 20S SE...
INCREASING A FEW DEGREES TUE NIGHT...LOW TO MID 20S. CURRENT
APPARENT TEMPERATURES TUESDAY MORNING RANGE FROM 10 DEGREES NW TO
MID TEENS SE.
WEDNESDAY AND THURSDAY: TEMPS WILL MODERATE WED AND THU...WITH HIGHS
BACK INTO THE 40S AND LOWS INCREASING FROM THE MID TO UPPER 20S WED
NIGHT TO UPPER 20S TO LOW 30S THU NIGHT. SIGNIFICANT DIFFERENCES IN
THE MEDIUM RANGE MODELS FOR MID TO LATE WEEK YIELD LOW FORECAST
CONFIDENCE...BUT FOR NOW THE FORECAST APPEARS TO BE DRY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 705 AM FRIDAY...
24 HOUR TAF PERIOD: VFR CONDITIONS THIS WILL GIVE WAY TO WIDESPREAD
IFR TO LIFR CONDITIONS IN RAIN THIS AFTERNOON AND EVENING.
A DEVELOPING AREA OF LOW PRESSURE ALONG THE NORTHERN GULF OF MEXICO
WILL TRACK NEWD THROUGH THE SOUTHEAST TODAY AND THEN ACROSS NORTH
CAROLINA THIS EVENING...BEFORE MOVING UP THE MID-ATLANTIC ON
SATURDAY.
RAIN WILL SPREAD SW TO NE INTO THE AREA LATE THIS MORNING THROUGH
THE EVENING WITH CEILINGS DETERIORATING TO IFR AND POSSIBLY LIFR INTO.
RAIN WILL BE MODERATE TO HEAVY AT TIMES...SO EXPECT SIGNIFICANT
REDUCTION IN VISIBILITIES AS WELL. RAIN SHOULD TAPER OFF FROM SW TO
NE BETWEEN 00Z TO 06Z...WITH VFR CONDITIONS RETURNING SATURDAY
MORNING.
OUTLOOK: AN UPPER LEVEL DISTURBANCE MOVING THROUGH THE AREA LATE
SATURDAY/SUNDAY MORNING COULD BRING SOME MVFR CEILINGS ACROSS THE
AREA ALONG WITH A BRIEF PERIOD OF RAIN/SNOW MIX. VFR CONDITIONS WILL
THEN DOMINATE EARLY TO MID NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL/22
SHORT TERM...CBL
LONG TERM...KC
AVIATION...CBL
Area Forecast Discussion
National Weather Service Spokane WA
454 AM PST FRI JAN 15 2016
.SYNOPSIS...
The region will be void of any significant storm systems through
today however that will change Saturday with the next round of
light to moderate snow for most locations outside the deep Basin.
Two more storm systems will bring mountain snow and mix of rain
and snow in the valleys Sunday through early next week.
&&
.DISCUSSION...
Today and tonight...this will be the period of relatively quiet
weather before the next weather system moves into the region late
tonight. The main weather problem for the day will revolve around
areas of stratus and fog. The latest fog product shows widespread
stratus and patchy fog across much of eastern Washington and north
Idaho. Most of it was north of a line from Wenatchee and Ephrata
to Mullan Pass, as well as some patchy stratus near the WA/OR
border. While we expect it to spread a little more this morning,
most of it will remain confined to these area. The mixing
potential through the stratus and sub-cloud layer looks rather
limited and thus we expect to see the fog persist at least into
the early afternoon hours, if not a little longer, especially
across the northern Columbia Basin. At this time a few of the
areas, including the West Plains of Spokane, parts of I-90 through
Spokane, and near Sandpoint, were visibilities of a quarter mile
or less, but it was far from widespread so a dense fog advisory is
not anticipated at this time.
Aside from the fog we are looking at a small chance of light snow
due to two weak systems. The first is currently near the ID/BC
border and is slowly sagging SE. Radar isn`t showing any returns,
however there were a few surface observations of light snow in BC
and IR satellite is showing some cool cloud tops in that area.
This should mainly be an early morning feature. The other will
revolve around weak NW-SE oriented cloud band over SW WA and
moving slowly eastward as upper level shortwave trough moves
through eastern Oregon this morning. Model guidance is not
consistent on this feature and in fact the Herr is showing very
little if any precipitation. This this might be the way to go as
even the models which show precip later today and early this
evening show a relatively dry layer. So even if snow were to
develop it would likely be very light. Suspect best chances later
this afternoon and evening will occur over SE WA/NC ID. Late
tonight the weather will focus around a much stronger weather
system which will deliver its main winter impacts on Saturday. fx
...NEXT WEATHER SYSTEM TO BRING SNOW TO PARTS OF THE INLAND
NORTHWEST ON SATURDAY...MODERATE SNOW AMOUNTS POSSIBLE NEAR THE
CASCADES...
Saturday: Upper level ridge gets pushed east as a moist
system from the Pacific moves into the Pacific Northwest.
Precipitation will move into the Cascades early Saturday morning
and spread east through the morning and early afternoon hours.
Cold air in place as well as upslope flow into the Cascades will
provide moderate snowfall through the day. The main area of
concern for snowfall will be the east slopes of the Cascades,
Wenatchee area, Waterville Plateau and the Okanogan Valley. Have
decided to issue a winter weather watch for these areas on
Saturday.
The Columbia Basin/Palouse along and south of I90 should be
mostly rain through the day. North of I90 they will see all snow
or a rain/snow mix.
For the Spokane area expect snow in the morning then changing
over to rain/snow mix or rain by the afternoon. Models seem to not
be as bullish as they were yesterday with the warm air intrusion,
and have therefore lowered snow levels, especially for the COE
area. Where Spokane will likely see less than an inch of snow, COE
may see up to 2 inches.
Northeast WA and north ID will experience an all snow event as
the warm air will not reach them until Sunday. Valleys will likely
see a few inches of snow througout the day and confidence is
increasing of a possible winter weather advisory for those areas
Sat and Sat night.
Have also lowered snow levels for the Blue Mountains and Camas
Prairie where they could pick up a few inches as well on Saturday.
Precipitation Will generally decrease through the evening and
overnight hours before the next system arrives Sunday.
Sunday: Another system will move into the region with a very
similar track to Saturday`s system. The big difference is snow
levels will be higher. By Sunday morning snow levels will be
around 2500 feet, so mostly a valley rain and mountain snow event
is expected. Models seem to have slowed down the timing a bit, so
it will linger through the evening and overnight hours across
extreme eastern WA and north ID.
Monday through Friday: We remain in a fairly progressive pattern.
Models are not handling features very well and the 00Z GFS now
creates a much stronger trough and low pressure system to move
into the area Tuesday night and Wednesday. So, did not make
changes to the forecast. Near Climo chance of precipitation and
temperatures are expected. /Nisbet
&&
.AVIATION... 12Z TAFS: This is a very low confidence
forecast. Widespread low clouds and fog with IFR/LIFR conditions
expected to continue through much of the day for SFF COE EAT and GEG
as there isn`t much in the atmosphere to break up the low level
inversion. The 12z Spokane sounding showed the inversion was up to
nearly 4000` with plenty of moisture trapped within the layer. So
confidence is high that the poor flight conditions for these
locations will continue but how much variance between the various
IFR/LIFR cigs and visibilities is tough to forecast. The HRRR is
hinting that conditions could improve shortly after 20z, but not
sure that will be the case. We did go for a slight improvement after
that but for the most part we will stick with IFR conditions. For
the other sites, there is nothing on satellite nearby but a nearly
saturated air mass could lead to a rapid onset of fog and IFR
conditions. Aside from the low clouds and fog, a couple weak systems
could deliver brief flurries beginning around midday near the
Cascades and to the ID/WA border around 00z. Much better chances of
significant snow arrives to MWH and EAT between 08-11z with a good
chance of IFR conditions. The snow will hold off until the very end
of the forecast for the other sites. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 27 36 32 39 34 / 20 20 100 40 80 60
Coeur d`Alene 31 27 36 33 39 36 / 20 30 100 70 80 80
Pullman 33 30 38 33 41 36 / 20 30 100 50 90 80
Lewiston 39 32 42 35 43 40 / 20 30 90 50 60 70
Colville 32 25 35 32 38 36 / 20 20 100 40 70 60
Sandpoint 32 26 34 33 38 36 / 40 30 90 90 70 80
Kellogg 32 27 35 33 36 34 / 40 30 90 90 70 80
Moses Lake 33 29 36 29 38 32 / 30 30 100 10 70 30
Wenatchee 32 29 35 31 39 34 / 20 40 100 10 90 30
Omak 29 26 35 32 36 32 / 10 40 100 10 80 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Winter Storm Watch from late tonight through Saturday evening
for East Slopes Northern Cascades-Okanogan Valley-
Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS TUCSON AZ
1005 AM MST FRI JAN 15 2016
.SYNOPSIS...A FEW SHOWERS NORTHEAST OF TUCSON INTO THIS EVENING
WITH BREEZY WINDS AT TIMES. OTHERWISE...DRY CONDITIONS WILL PREVAIL
ACROSS MUCH OF THE AREA THIS WEEKEND AND DURING THE UPCOMING WEEK.
A WEATHER SYSTEM MAY BRING A FEW SHOWERS MAINLY TO THE WHITE
MOUNTAINS WEDNESDAY. EXPECT COOL MORNINGS THIS WEEKEND EVEN AS
DAYTIME TEMPERATURES CLIMB ABOVE AVERAGE BY MONDAY.
&&
.DISCUSSION...A POSITIVE TILTED SHORTWAVE TROUGH WAS OVER THE GREAT
BASIN THIS MORNING. IR SATELLITE IMAGERY DURING THE PAST 2-3 HOURS
DEPICTED COOLING CLOUD TOPS AHEAD OF THIS SYSTEM...ESPECIALLY OVER
NORTH CENTRAL/NE ARIZONA. THIS SYSTEM IS PROGGED VIA THE 15/12Z NAM/
GFS/CMC AND 15/00Z ECMWF TO MOVE SEWD ACROSS THE FOUR CORNERS REGION
THIS EVENING. THE MID-LEVEL TROUGH AXIS IS THEN PROGGED TO BE EAST
OF THIS FORECAST AREA BY MIDNIGHT TONIGHT.
BASED ON THE ABOVE NWP SOLUTIONS AS WELL AS SEVERAL HRRR SOLUTIONS...
THE OFFICIAL FORECAST WAS UPDATED WITH SOMEWHAT HIGHER POPS
PARTICULARLY ACROSS THE WHITE MOUNTAINS THIS AFTERNOON AND EVENING.
HOWEVER...LIQUID AMOUNTS AND SNOW ACCUMULATIONS WERE ESSENTIALLY
UNCHANGED. THUS...SCATTERED TO NUMEROUS SNOW SHOWERS ARE FORECAST
TO OCCUR THIS AFTERNOON/EVENING ACROSS THE MOUNTAINS OF GRAHAM/
GREENLEE COUNTIES.
MEANWHILE...ISOLATED VALLEY RAIN SHOWERS SHOULD ALSO OCCUR ACROSS
GRAHAM COUNTY INCLUDING SAFFORD...AND A SLIGHT CHANCE OF SNOW SHOWERS
CONTINUES FURTHER SOUTHWEST TO THE CATALINA/RINCON MOUNTAINS NEAR
TUCSON. ANY MEASURABLE PRECIP IS EXPECTED TO END AROUND MIDNIGHT
TONIGHT. LIQUID AMOUNTS WILL BE MAINLY LESS THAN ONE TENTH OF AN
INCH. SNOW ACCUMS FOR HANNAGAN MEADOW AND MOUNT GRAHAM WILL RANGE
FROM 1-2 INCHES...AND LITTLE IF ANY SNOW ACCUMS WILL OCCUR ACROSS THE
CATALINA/RINCON MOUNTAINS.
GUSTY WEST-TO-NORTHWEST WINDS WILL ALSO PREVAIL THIS AFTERNOON AND
EVENING...WITH STRONGEST WINDS TO OCCUR ACROSS THE UPPER GILA RIVER
VALLEY INCLUDING SAFFORD. HIGH TEMPS TODAY WILL BE NEARLY IDENTICAL
TO TEMPS ACHIEVED THUR FROM TUCSON WWD ACROSS THE WESTERN DESERTS...
BUT WILL BE ABOUT 5 DEGS COOLER EAST AND SOUTH OF TUCSON.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 16/18Z.
EXPECT ISOLATED TO SCATTERED -SHRA AND HIGHER TERRAIN -SHSN
GENERALLY FROM KSAD VICINITY NEWD ACROSS THE WHITE MOUNTAINS THIS
AFTERNOON AND EVENING. THIS PRECIPITATION SHOULD BE EAST OF THE
SOUTHEAST ARIZONA/SOUTHWEST NEW MEXICO BORDER BY 17/07Z. OTHERWISE...
SCATTERED TO BROKEN CLOUDS AROUND 10K-15K FT MSL WITH LAYERED CLOUDS
ABOVE 20K FT MSL INTO SATURDAY MORNING. SURFACE WIND THIS AFTERNOON
AND EARLY EVENING WILL BE WLY/NWLY AT 12-25 KTS WITH GUSTS OF 25-35
KTS. THE STRONGEST WINDS WILL BE EAST OF KTUS. SURFACE WIND WILL
DIMINISH TO LESS THAN 10 KTS ACROSS MUCH OF THE AREA AROUND 17/07Z
AND CONTINUE INTO SATURDAY MORNING. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...ISOLATED TO SCATTERED VALLEY RAIN AND MOUNTAIN SNOW
SHOWERS WILL OCCUR FROM THE CATALINA/RINCON MOUNTAINS NEAR TUCSON
NORTHEASTWARD TO THE WHITE MOUNTAINS THIS AFTERNOON AND EVENING. A
SLIGHT CHANCE OF VALLEY RAIN/MOUNTAIN SNOW SHOWERS EXISTS TUESDAY
NIGHT AND WEDNESDAY FROM TUCSON EASTWARD TO THE NEW MEXICO BORDER.
OTHERWISE...DRY CONDITIONS WILL PREVAIL THROUGH NEXT THURSDAY.
FRIDAY. EXPECT WEST TO NORTHWEST 20-FOOT WINDS OF 10-20 MPH WITH
GUSTS TO AROUND 30 MPH THIS AFTERNOON AND EVENING. THE STRONGEST
WINDS WILL BE EAST OF TUCSON AND ESPECIALLY ACROSS THE UPPER GILA
RIVER VALLEY INCLUDING SAFFORD. OTHERWISE...20-FOOT WINDS WILL
GENERALLY BE TERRAIN DRIVEN AT LESS THAN 15 MPH.
&&
.PREV DISCUSSION /245 AM MST/...AFTER FEW CHILLY MORNINGS SATURDAY
INTO MONDAY A RIDGE BRINGS A RETURN OF THE AFTERNOON WARMING TREND TO
THE FORECAST EARLY NEXT WEEK. SOME MODEL DIFFERENCES ON A POSSIBLE
SYSTEM NEXT WEDNESDAY...BUT EVEN WITH THE MOST AGGRESSIVE MODEL
RESOLUTIONS THE PATTERN DOES NOT SUPPORT A SYSTEM THAT WOULD DELIVER
SIGNIFICANT PRECIP TO THE AREA. SOME EARLY SIGNS OF ANOTHER PATTERN
CHANGE LATE IN THE MONTH THAT WOULD TEND TO SPLIT ENERGY INTO LOWER
LATITUDES OFF THE PACIFIC AGAIN.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
FRANCIS/MEYER/HUMPHREYS
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
104 PM PST FRI JAN 15 2016
...SERIES OF SYSTEMS TO IMPACT OUR AREA THROUGH THE END OF NEXT
WEEK WITH THE STRONGEST SYSTEM EXPECTED SUNDAY EVENING INTO MONDAY
MORNING...
.SYNOPSIS...A WEAK SYSTEM IS EXPECTED TO MOVE ACROSS NORTHERN
CALIFORNIA LATER TODAY AND BRING RAIN BACK TO OUR AREA TONIGHT. A
SERIES OF SYSTEMS WILL AFFECT THE AREA SATURDAY THROUGH AT LEAST
THE END OF NEXT WEEK. THE STRONGEST SYSTEM IS SLATED FOR SUNDAY
EVENING INTO TUESDAY.
&&
.DISCUSSION...AS OF 1:00 PM PST FRIDAY...MIX OF CLOUDS AND SUN
ACROSS THE REGION TODAY WITH TEMPERATURES RUNNING CLOSE TO VALUES
24 HOURS AGO. TEMPS DO RANGE FROM THE LOWER 50S IN THE NORTH BAY
WHERE CLOUDS HAVE BEEN VERY SLOW TO BURN OFF, TO THE UPPER 50S TO
LOWER 60S FOR THE REST OF OUR AREA THAT ENJOYED MORE SUNSHINE.
A WEAK SYSTEM WILL MOVE TO THE COAST THIS EVENING WITH RAINFALL
FORECAST TO RETURN TO THE NORTH BAY FIRST THEN DOWN TO THE SF BAY
REGION LATE IN THE EVENING. THE RAIN WILL CONTINUE TO PROGRESS TO
THE SOUTH AND EAST OVERNIGHT WITH SAN JOSE AND MONTEREY BOTH
LOOKING AT START TIMES FOR PRECIPITATION AT OR JUST AFTER MIDNIGHT.
RAIN WILL SWITCH OVER TO SCATTERED SHOWERS BY LATE SATURDAY
MORNING. RAINFALL TOTALS WILL GENERALLY BE UNDER 1/3" FOR URBAN
SPOTS WITH LOCALLY 1/2" TO 1" IN THE COASTAL RANGES. HRRR DOES
INDICATE MORE WIDESPREAD LIGHT RAINFALL COMPARED TO YESTERDAY`S
SYSTEM, SO LOCATIONS THAT WERE DRY OR JUST GOT A TRACE YESTERDAY
SHOULD DO A BIT BETTER.
SUNDAY WILL START OUT GENERALLY DRY BEFORE THE MAIN SYSTEM OF THE
SERIES ADVANCES INTO THE REGION BEGINNING SUNDAY EVENING. MODELS
REMAIN IN FAIRLY GOOD AGREEMENT THAT RAIN WILL MOVE BACK TO THE
NORTH BAY IN THE EVENING AND THEN DOWN TO SF BAY AND MONTEREY BAY
REGION FOR THE OVERNIGHT HOURS. RAINFALL WILL LIKELY BE MODERATE
TO HEAVY AT TIMES AS THE FRONT GOES THROUGH THANKS IN PART TO PW
VALUES NEAR 1.3". ON THE POSITIVE SIDE, IT LOOKS LIKE THE HEAVIEST RAINFALL
WILL LIKELY COINCIDE WITH THE NIGHT BEFORE MLK HOLIDAY SUGGESTING
THAT TRAFFIC SHOULD BE AT EXTREMELY LOW LEVELS. RAINFALL TOTALS
WILL GENERALLY BE 1/2" TO 1" IN MANY URBAN SPOTS WITH 1-3" AT
COASTAL RANGES (ISOLATED 4+"). THE OTHER STORY WITH THIS SYSTEM
WILL BE LOCALLY GUSTY SOUTHERLY WINDS JUST AHEAD OF THE FRONT.
SOUTHERLY WINDS OF 15 TO 25 MPH GUSTING TO 35 MPH CAN BE EXPECTED
SUNDAY AFTERNOON INTO THE EVENING.
RAIN WILL AGAIN SWITCH TO SHOWERS WITH JUST LIGHT PRECIPITATION
EXPECTED FOR MONDAY AFTERNOON.
PREVIOUS MODEL GUIDANCE INDICATED A SECOND SLUG OF MOISTURE POISED
TO MOVE THROUGH LAST MONDAY INTO TUESDAY. HOWEVER THAT NOW APPEARS
MUCH LESS LIKELY BASED OFF OF THE ENSEMBLE PLUS MOST OPERATIONAL
MODELS. NOW APPEARS THAT INSTEAD A SHORTWAVE WILL MOVE TO THE PAC
NW COAST TUESDAY EVENING/NIGHT AND BRING SOME MORE LIGHT RAIN TO
OUR REGION. SINCE THIS WAS A HUGE CHANGE FROM THE PREVIOUS
PACKAGE, POPS AND QPF WERE BOTH GREATLY REDUCED FOR MONDAY NIGHT
INTO TUESDAY. HOWEVER, DID NOT FEEL COMFORTABLE GOING COMPLETELY
DRY WHICH SOME OF THE MODELS ARE NOW INDICATING. BOTTOM
LINE...MONDAY NIGHT INTO TUESDAY CURRENTLY LOOKS LIKE A NON-EVENT
WITH JUST LIGHT RAIN POSSIBLE IN THE WORST CASE.
BEYOND TUESDAY, ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH
THE END OF THE MONTH.
&&
.AVIATION...AS OF 10:00 AM PST FRIDAY...FOR 18Z TAFS. VFR TODAY
WITH PREDOMINATELY LIGHT SOUTHEAST WINDS. APPROACHING STORM SYSTEM
WILL BRING RAIN TO THE AREA FROM NORTHWEST TO SOUTHEAST BTWN 03Z
SAT THROUGH 15Z SAT... THEN LINGERING RAIN SHOWERS THROUGH 03Z
SUN. CIGS WILL DETERIORATE INTO MVFR RANGE EARLY IN THE EVENT...
AND DROP INTO IFR RANGE FOR SOME LOCATIONS AFTER 10-12Z SAT AND
REMAIN IN IFR-MVFR RANGE THROUGH SATURDAY MORNING. PREDOMINATELY
SOUTH TO SOUTHEAST WINDS WILL PREVAIL THROUGH THE TAF PERIOD...
WITH BRIEF VARIABLE SHIFTS TO OTHER DIRECTIONS.
VICINITY OF KSFO... VFR THROUGH 03Z SAT... THEN DETERIORATING CIGS
DOWN TO MVFR RANGE THROUGH REMAINDER OF TAF PERIOD. RA TO SHRA
FROM 05Z THROUGH END OF TAF PERIOD. PREDOMINATELY EAST WINDS
THROUGH THE MORNING THEN SOUTHEAST WINDS WILL PREVAIL THROUGH
MIDDAY SATURDAY. HEAVIEST RAIN CURRENTLY EXPECTED BETWEEN 06-10Z
SAT.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR CIGS WITH LIGHT VARIABLE WINDS
THROUGH THE DAYLIGHT HOURS. LIGHT SOUTHEAST WINDS AND INCREASING
MID CLOUDS BEGINNING AROUND 05-06Z SAT THEN DETERIORATING CIGS TO
MVFR/IFR RANGE AFTER 08-10Z. HEAVIEST RAIN SLOTTED BETWEEN 08-011Z
SAT.
&&
.MARINE...AS OF 11:38 AM PST FRIDAY...LIGHT VARIABLE WINDS THROUGH
EARLY THIS AFTERNOON. WINDS INCREASE AND SHIFT TO BECOME SOUTHERLY
LATER THIS AFTERNOON AND INTO THIS EVENING AHEAD OF AN APPROACHING
FRONT. THE STRONGEST WINDS WILL BE OVER THE NORTHERN OUTER WATERS
THROUGH SATURDAY. BY SATURDAY AFTERNOON A LARGE AND LONG PERIOD
SWELL TRAIN WILL SPREAD THROUGH THE WATERS WITH LARGE SEAS AND
SOUTHERLY WINDS THROUGH THE REST OF THE WEEKEND AS MORE STRONG
STORMS TAKE AIM TOWARDS CAPE MENDOCINO.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 1 AM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 2 AM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
228 PM CST FRI JAN 15 2016
.SHORT TERM...(Tonight)
ISSUED AT 228 PM CST FRI JAN 15 2016
20z/2pm surface analysis shows cold front pushing east of the I-57
corridor, as the area of rain ahead of the boundary exits into
Indiana. While temperatures are still in the lower to middle 40s
across the E/SE KILX CWA, readings have dropped into the lower to
middle 30s further west across the remainder of the area.
Temperatures will continue to fall over the next couple of hours,
with readings ranging from the upper 20s in the Illinois River
Valley...to the upper 30s across the far SE around Lawrenceville by
early evening. Latest satellite imagery shows plenty of clouds
upstream across central/eastern Iowa, with the closest appreciable
clearing over western sections of Minnesota/Iowa. HRRR shows this
clear spot shifting southeastward and remaining W/SW of the CWA
tonight. Further north, HRRR is hinting that some breaks in the
overcast will develop across Wisconsin later tonight: however, any
clearing from the north will likely not occur until Saturday
morning. As a result, am going with a cloudy forecast tonight, with
a few flurries possible along/north of I-72 during the evening.
Overnight low temperatures will range from the teens northwest of
the Illinois River to the upper 20s southeast of I-70.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 228 PM CST FRI JAN 15 2016
Large high pressure ridge will move into the area and affect the CWA
beginning tomorrow. However, a clipper system will move toward the
area tomorrow evening and then into the CWA late tomorrow night. The
snow will push into the northwest parts of the CWA and then spread
east southeast across the remainder of the CWA Sunday morning. If
any area of the CWA does not get snow, it will be in southeast IL.
Northwest winds will be a tad breezy on Sunday as this clipper
system pushes east and out of the area. Dry weather is then expected
through Mon night with cold high pressure dominating the weather
pattern at the end of the weekend and into the beginning of next
week.
Temps will become very cold this weekend as the cold air associated
with the high pressure pours into the area this weekend. Temps will
drop into the single digits along and northwest of the IL river for
Sat night, with wind chills in the range of -10 to -15, which is
close to wind chill advisory. Temps will get much colder Sun night
into Mon morning, with low temps in the single digits in southeast
IL and below zero over the remainder of the CWA, north of I-70.
Combined with the wind, resulting wind chills Sun night will range
from 15 to 25 degrees below zero over most of the area...which is
wind chill advisory criteria.
Another clipper-type weather system will move across the area Tue
thru Wed and produce another round of light snow in the area. Models
differ on speed/timing of this system but appears that most of the
snow will be on Tue night and Wed. After this system moves through,
ECMWF and GFS agree that any additional systems will get pushed
further south leaving the CWA dry from Wed night through Fri.
However, the Canadian model brings another clipper system through
the area mid week with more snow, which agreed with some older model
runs. Blend of the models gives more chance pops, but prefer better
agreement of the ECMWF and GFS. So for now, will just lower pops to
slight chance for Wed night thru Fri; though thinking is that a dry
forecast is what will be seen in later forecasts.
Temps will start cold with Mon night temps remaining well below
normal. Then temps gradually warm back up but not reaching normal
through end of the week. Extended model guidance does not look that
bad, but kept a degree or two below guidance for now.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1152 AM CST FRI JAN 15 2016
Cold front continues to push eastward late this morning, with
latest obs showing it approaching the I-57 corridor. Southwesterly
winds and rain will persist at KCMI through 19z before the front
passes and winds veer to the northwest. Despite FROPA, low clouds
blanket the region westward into Iowa/Minnesota. Ceilings are
generally low MVFR: however, an area of IFR ceilings is noted
across eastern Iowa into west-central Illinois. Based on satellite
timing tools and to a lesser extent the HRRR forecast, have
introduced a period of IFR at KPIA and KSPI through the 21z/22z
time frame. After that, GFS forecast soundings suggest MVFR
ceilings of around 1500ft will prevail from late afternoon through
the night. Big question will be how fast to clear things off on
Saturday. NAM appears to be suffering from its usual low-level
moist bias within the strong CAA regime, so have trended toward
the GFS. As such, have scattered clouds at KPIA by 14z, but have
maintained overcast conditions further east at KCMI through 18z
Sat.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Auten
AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1152 AM CST FRI JAN 15 2016
.UPDATE...
ISSUED AT 1048 AM CST FRI JAN 15 2016
16z/10am surface analysis shows cold front along the I-55
corridor, with an area of light to moderate rain occurring ahead
of the front across much of the eastern KILX CWA. Based on 12z
NAM/HRRR, it appears the front will clear the eastern CWA by
21z/3pm. Have increased PoPs to categorical ahead of the front
and have fine-tuned the timing of precip departure this afternoon.
Once the front passes, winds veer to the W/NW and temperatures
drop abruptly. Temperatures have fallen into the upper 20s and
lower 30s west of the Illinois River...and this colder air will
push eastward across the remainder of the area this afternoon.
Highs will mainly be in the lower to middle 40s, although a few
readings near 50 degrees will be possible across the SE counties
before temps fall after FROPA. Have noted a few snow
flurries/snow-showers upstream across central and northern Iowa
and think these will spread into north-central Illinois this
afternoon. HRRR hints at this as well, so have added scattered
flurries to the forecast along/north of a Rushville to Bloomington
line later today.
&&
.SHORT TERM...(Today)
ISSUED AT 229 AM CST FRI JAN 15 2016
Latest surface analysis had low pressure centered over southwest
Wisconsin, with the trailing cold front extending southwest into the
southern Plains. The low is forecast to reach eastern Michigan by
this evening, with the cold front expected to be east of the forecast
area by mid-afternoon. The front is strong temperature-wise, and
temperatures will be falling in its wake. This will result in high
temperatures being reached early this morning across west-central
Illinois, with temperatures likely falling for the rest of the day.
The biggest question with respect the front is if it will provide
precipitation across central and southeast Illinois. The airmass the
front is moving into is quite dry per 00Z ILX and forecast
soundings. This is also shown by the significant lack of cloud cover
showing up in local surface observations (clouds below 12K feet).
The only nearby rainfall at the moment is a thin line of showers
along the front in Missouri. Model guidance continues to suggest
that the rainfall will expand within the pre-frontal WAA/isentropic
lift. However, there is not much time for moistening to occur before
FROPA across at least the western portion of the forecast area.
Still expect at least a few hour period of rain across the eastern
portion of the forecast area, mainly before noon, but significant
rainfall is not anticipated. Forecast soundings suggest the
precipitation will cut off before temperatures are cold enough for
snow.
.LONG TERM...(Tonight through Thursday)
ISSUED AT 229 AM CST FRI JAN 15 2016
Next lobe of Arctic air poised to start its southward push,
associated with a large upper low currently just north of Lake
Winnipeg. More recent model runs are a bit slower in getting the
core of the cold air mass this far south, with the strongest surge
taking place Sunday as 850 mb temps drop to around -21C. Thus, made
some adjustments with the temperatures for Saturday night and Sunday
by bringing them up a few degrees, which will lessen the risk of
needing a wind chill advisory as early as Saturday night. Sunday
night still looking to be the coldest, with wind chills of -15F as
far south as I-70 and many areas seeing lows below zero.
In regards to the weekend snow threat, with the upper low itself a
bit delayed in arriving, have backed off some with the snow chances
late Saturday night and mainly limited them northwest of the
Illinois River. Main threat will be Sunday morning, but the window
of opportunity appears to be shrinking as most of the models
diminish the amount of precip accumulation as the wave passes
through. Thus, left PoP`s generally in the 30% range for now, with
some slight chances lingering across the southeast half of the CWA
into afternoon.
Longer range remains a bit challenging as the Arctic air mass exits.
The latest ECMWF now suggests mainly a Tuesday night-Wednesday
morning event with the wave that will be dropping out of the
Dakotas, while the GFS a more pronounced and longer-lasting system
due to a more prominent upper trough extending south into Texas.
This results in that model featuring a broad trough and cooler air
persisting into mid week, while the ECMWF quickly warms ahead of the
late week system. Model performance this far out has not been
consistent as of late, leading to lower confidence for the forecast
details beyond Wednesday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1152 AM CST FRI JAN 15 2016
Cold front continues to push eastward late this morning, with
latest obs showing it approaching the I-57 corridor. Southwesterly
winds and rain will persist at KCMI through 19z before the front
passes and winds veer to the northwest. Despite FROPA, low clouds
blanket the region westward into Iowa/Minnesota. Ceilings are
generally low MVFR: however, an area of IFR ceilings is noted
across eastern Iowa into west-central Illinois. Based on satellite
timing tools and to a lesser extent the HRRR forecast, have
introduced a period of IFR at KPIA and KSPI through the 21z/22z
time frame. After that, GFS forecast soundings suggest MVFR
ceilings of around 1500ft will prevail from late afternoon through
the night. Big question will be how fast to clear things off on
Saturday. NAM appears to be suffering from its usual low-level
moist bias within the strong CAA regime, so have trended toward
the GFS. As such, have scattered clouds at KPIA by 14z, but have
maintained overcast conditions further east at KCMI through 18z
Sat.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...BAK
LONG TERM...Geelhart
AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1048 AM CST FRI JAN 15 2016
.UPDATE...
ISSUED AT 1048 AM CST FRI JAN 15 2016
16z/10am surface analysis shows cold front along the I-55
corridor, with an area of light to moderate rain occurring ahead
of the front across much of the eastern KILX CWA. Based on 12z
NAM/HRRR, it appears the front will clear the eastern CWA by
21z/3pm. Have increased PoPs to categorical ahead of the front
and have fine-tuned the timing of precip departure this afternoon.
Once the front passes, winds veer to the W/NW and temperatures
drop abruptly. Temperatures have fallen into the upper 20s and
lower 30s west of the Illinois River...and this colder air will
push eastward across the remainder of the area this afternoon.
Highs will mainly be in the lower to middle 40s, although a few
readings near 50 degrees will be possible across the SE counties
before temps fall after FROPA. Have noted a few snow
flurries/snow-showers upstream across central and northern Iowa
and think these will spread into north-central Illinois this
afternoon. HRRR hints at this as well, so have added scattered
flurries to the forecast along/north of a Rushville to Bloomington
line later today.
&&
.SHORT TERM...(Today)
ISSUED AT 229 AM CST FRI JAN 15 2016
Latest surface analysis had low pressure centered over southwest
Wisconsin, with the trailing cold front extending southwest into the
southern Plains. The low is forecast to reach eastern Michigan by
this evening, with the cold front expected to be east of the forecast
area by mid-afternoon. The front is strong temperature-wise, and
temperatures will be falling in its wake. This will result in high
temperatures being reached early this morning across west-central
Illinois, with temperatures likely falling for the rest of the day.
The biggest question with respect the front is if it will provide
precipitation across central and southeast Illinois. The airmass the
front is moving into is quite dry per 00Z ILX and forecast
soundings. This is also shown by the significant lack of cloud cover
showing up in local surface observations (clouds below 12K feet).
The only nearby rainfall at the moment is a thin line of showers
along the front in Missouri. Model guidance continues to suggest
that the rainfall will expand within the pre-frontal WAA/isentropic
lift. However, there is not much time for moistening to occur before
FROPA across at least the western portion of the forecast area.
Still expect at least a few hour period of rain across the eastern
portion of the forecast area, mainly before noon, but significant
rainfall is not anticipated. Forecast soundings suggest the
precipitation will cut off before temperatures are cold enough for
snow.
.LONG TERM...(Tonight through Thursday)
ISSUED AT 229 AM CST FRI JAN 15 2016
Next lobe of Arctic air poised to start its southward push,
associated with a large upper low currently just north of Lake
Winnipeg. More recent model runs are a bit slower in getting the
core of the cold air mass this far south, with the strongest surge
taking place Sunday as 850 mb temps drop to around -21C. Thus, made
some adjustments with the temperatures for Saturday night and Sunday
by bringing them up a few degrees, which will lessen the risk of
needing a wind chill advisory as early as Saturday night. Sunday
night still looking to be the coldest, with wind chills of -15F as
far south as I-70 and many areas seeing lows below zero.
In regards to the weekend snow threat, with the upper low itself a
bit delayed in arriving, have backed off some with the snow chances
late Saturday night and mainly limited them northwest of the
Illinois River. Main threat will be Sunday morning, but the window
of opportunity appears to be shrinking as most of the models
diminish the amount of precip accumulation as the wave passes
through. Thus, left PoP`s generally in the 30% range for now, with
some slight chances lingering across the southeast half of the CWA
into afternoon.
Longer range remains a bit challenging as the Arctic air mass exits.
The latest ECMWF now suggests mainly a Tuesday night-Wednesday
morning event with the wave that will be dropping out of the
Dakotas, while the GFS a more pronounced and longer-lasting system
due to a more prominent upper trough extending south into Texas.
This results in that model featuring a broad trough and cooler air
persisting into mid week, while the ECMWF quickly warms ahead of the
late week system. Model performance this far out has not been
consistent as of late, leading to lower confidence for the forecast
details beyond Wednesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 558 AM CST FRI JAN 15 2016
CIGS will gradually lower to MVFR, or possibly IFR, today as a
cold front pushes into the area and low-level moisture increases.
A few rain showers are possible ahead of the front, but
significant precipitation is not anticipated. Winds will swing
around to the west-northwest behind the front later today and
become gusty for several hours.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...BAK
LONG TERM...Geelhart
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS JACKSON KY
351 PM EST FRI JAN 15 2016
.UPDATE...
ISSUED AT 132 PM EST FRI JAN 15 2016
RAIN FROM SE SYSTEM HAS PROGRESS AS FAR NW AS KJKL...AND HAVE
UPDATED WITH HIGHER AFTERNOON POPS OVER THE SE PART OF THE AREA.
UPDATE ISSUED AT 1157 AM EST FRI JAN 15 2016
SYSTEM MOVING THROUGH THE SE CONUS WILL END UP HAVING A GREATER
INFLUENCE ON OUR LOCAL AREA THAN EARLIER FORECAST. RAIN IS
SPREADING INTO OUR FAR SOUTHEAST COUNTIES...AND POPS HAVE BEEN
RAISED THERE FOR TODAY. WET BULB TEMPERATURES OVER THE HIGH
ELEVATIONS NEAR THE VA BORDER ARE BELOW FREEZING...AND THIS COULD
ALLOW FOR SOME SNOW TO INITIALLY OCCUR AS PRECIP MOVES IN...BUT IT
SHOULD FADE AWAY AS WET BULB READINGS EVENTUALLY RISE.
MEANWHILE... PRECIP OVER CENTRAL KY AHEAD OF A COLD FRONT HAS BEEN
SLOWER TO MAKE ITS WAY EAST THAN WAS EXPECTED...AND HAVE LOWERED
POPS TODAY AND HELD PRECIP OFF LONGER IN THE NW PART OF THE AREA.
WHAT IS LEFT OF THE FRONTAL PRECIP WILL MAKE ITS WAY ACROSS THE
REMAINDER OF OUR AREA...ESPECIALLY THE NORTH...THIS EVENING.
BEHIND THE COLD FRONT...POTENTIAL FOR PRECIP AND ITS TYPE REMAIN
ISSUES. MOISTURE WILL BE SHALLOW AND MAY NOT REACH -10C FOR ICE
FORMATION. HOWEVER...SURFACE TEMPS SHOULD EVENTUALLY REACH
FREEZING FOR SOME LOCATIONS. PRECIP TYPE COULD END UP BEING
DRIZZLE...FREEZING DRIZZLE...FLURRIES...OR SOME COMBINATION. AT
THIS POINT...HAVE ONLY USED SLIGHT CHANCE WORDING FOR THE
NONMEASURABLE PRECIP FROM LATE TONIGHT INTO SATURDAY NIGHT.
UPDATE ISSUED AT 751 AM EST FRI JAN 15 2016
FRESHENED UP THE HOURLY TEMPERATURES AND DEW POINTS. SHELTERED
VALLEYS ARE RANGING FROM THE MID 20S TO THE LOWER 30S...WITH MOST
OTHER LOCATIONS REPORTING IN THE LOW TO MID 40S. THICKER CLOUDS
ARE STARTING TO OVERTAKE THE AREA...WITH RAIN SHOWERS MOVING IN
ACROSS PORTIONS OF WESTERN KENTUCKY. THE LATEST HRRR GUIDANCE
CONTINUES TO SHOW LITTLE IN THE WAY OF SHOWER ACTIVITY UNTIL THIS
AFTERNOON...WHEN THE FAR SOUTHEAST MAY GET BRUSHED. WILL LET THE
CURRENT FORECAST RIDE FOR NOW. GRID UPDATES WILL BE FORTHCOMING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
SURFACE LOW PRESSURE IS CURRENTLY CRUISING TOWARDS THE GREAT
LAKES...WITH AN ATTENDANT COLD FRONT ALIGNED SOUTHWEST THROUGH THE
SOUTHERN PLAINS. ANOTHER LOW PRESSURE SYSTEM IS ORGANIZING ACROSS
THE NORTH CENTRAL GULF OF MEXICO...WITH HIGH PRESSURE RETREATING
OFF THE CAROLINA COAST. ALOFT...A SHORT WAVE TROUGH IS MOVING
ACROSS THE PLAINS WITHIN THE NORTHERN STREAM...WHILE ANOTHER ONE
IS MOVING THROUGH THE NORTH CENTRAL GULF WITHIN THE SOUTHERN
STREAM. THIS IS ALLOWING FOR DEEPER SOUTHWEST FLOW ACROSS THE MID
AND LOWER MISSISSIPPI VALLEY...WITH PLENTY OF HIGH CLOUDS
STREAMING IN FROM THE SOUTHWEST. EASTERN KENTUCKY REMAINS UNDER
PARTLY CLOUDY TO MOSTLY CLEAR SKIES...WITH TEMPERATURES VARYING
FROM THE MID TO UPPER 40S IN THE BROADER VALLEYS AND
RIDGETOPS...WHILE SHELTERED VALLEYS IN THE EAST REMAIN SOME 20
DEGREES COLDER...IN THE MID TO UPPER 20S.
THE TWO AFOREMENTIONED SYSTEMS WILL TRACK EAST TODAY...WITH
EASTERN KENTUCKY REMAINING SPLIT BETWEEN THEM. THE MODELS HAVE
TRENDED A BIT DRIER WITH THE SOUTHERN STREAM MOISTURE...KEEPING
MOST OF THIS JUST TO OUR SOUTHEAST. MOST OF THE FORCING WILL COME
FROM THE NORTHERN STREAM SYSTEM AS THE TROUGH AXIS AND SURFACE
COLD FRONT APPROACH FROM THE WEST. LIGHT RAIN SHOWERS WILL MOVE IN
FROM THE WEST TODAY...WITH THE MAJORITY OF THE ACTIVITY HOLDING
OFF UNTIL THIS AFTERNOON. THE BEST OVERALL RAIN CHANCES STILL LOOK
TO OCCUR IN THE FAR WEST...WITH LESSER CHANCES IN OUR NORTHEAST
COUNTIES. HIGHS TODAY WILL RECOVER INTO THE LOW TO MID 50S...WITH
SOME SPOTS REACHING THE UPPER 50S IN THE EAST...WHERE THICKER
CLOUD COVER WILL HOLD OFF THE LONGEST.
THE COLD FRONT AND TROUGH AXIS WILL SWING THROUGH THE AREA BETWEEN
00 AND 06Z TONIGHT...WITH A GOOD CHANCE OF LIGHT PRECIPITATION
CONTINUING. COLD ADVECTION WILL BE UNDERWAY OVERNIGHT...WITH LOWS
FOR MOST COOLING OFF TO THE LOW TO MID 30S. THE ONLY EXCEPTION
WILL BE THE HIGHER TERRAIN...WHERE LOWS WILL SETTLE INTO THE 20S.
HAVE LEFT A MENTION OF SNOW IN THE FORECAST TOWARDS DAWN SATURDAY
MORNING...HOWEVER WITH ICE IN QUESTION...DRIZZLE AND OR FREEZING
DRIZZLE MAY BECOME A CONCERN FOR THE HIGHER ELEVATIONS.
ANY LIGHT PRECIPITATION LINGERING INTO SATURDAY WILL TAPER OFF
DURING THE DAY AS FORCING DIMINISHES. HIGH TEMPERATURES WILL NOT
RECOVER MUCH DURING THE DAY WITH THICK CLOUD COVER LOCKED INTO
PLACE THANKS TO A POST-FRONTAL INVERSION. HAVE UNDERCUT THE
BLENDED GUIDANCE FOR THE HIGHS...ONLY ALLOWING FOR A FEW DEGREE
OR SO RISE FROM SATURDAY MORNING LOWS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 351 PM EST FRI JAN 15 2016
...COLDEST AIR OF SEASON LIKELY SUNDAY NIGHT THROUGH MONDAY NIGHT...
THE EXTENDED FORECAST PERIOD BEGINS ON SUNDAY NIGHT WITH A CONTINUED
ACTIVE AND AMPLIFIED PATTERN IN PLACE. STRONG RIDGING IS IN PLACE
OVER THE WESTERN CONUS WITH A DEEP AND BROAD LONGWAVE TROUGH OVER
THE EASTERN CONUS. A CLOSED LOW WILL THEN REMAIN IN PLACE OVER THE
GREAT LAKES REGION THROUGH MUCH OF THE EXTENDED BEFORE SHIFTING OFF
TO THE EAST AND INTO THE NEW ENGLAND REGION BY TUESDAY.
MEANWHILE...A COUPLE OF SHORTWAVES WILL ROTATE AROUND THE LOW AND
DIVE SOUTHEAST INTO THE OH VALLEY WITH THE FIRST TROUGH PASSING
THROUGH ON SUNDAY AND THE SECOND FEATURE PASSING THROUGH MONDAY
AFTERNOON INTO MONDAY NIGHT. THE SUNDAY SHORTWAVE DEVELOPS UNDER
SOME INTERACTION BETWEEN THE PFJ AND STJ OVER THE SOUTHEASTERN
CONUS. HOWEVER...THIS SET UP OCCURS A BIT FURTHER TO THE SOUTHEAST
KEEPING ANY SIGNIFICANT SNOWFALL TO THE SOUTH AND EAST.
THE SECOND WAVE THAT TRACKS SOUTHEAST THROUGH THE OH VALLEY WILL BE
A RELATIVELY DRY ARCTIC FRONT AS THE COLDEST AIR OF THE SEASON
FILTERS INTO THE AREA. IN FACT AS SKIES CLEAR OUT MONDAY NIGHT AND
WINDS DECREASE...SOME OF THE DEEPER VALLEYS MAY DROP TO NEAR OR EVEN
POSSIBLY BELOW ZERO ON TUESDAY MORNING. WIND CHILLS WILL LIKELY
BE IN THE 0 TO -10 RANGE.
BY WEDNESDAY...THE UPPER LEVEL PATTERN BECOMES LESS
AMPLIFIED...NEARLY ZONAL ACROSS THE EASTERN CONUS BUT MAINTAINING A
RIDGE OVER THE WEST. A SHORTWAVE WILL TRACK ACROSS THE FRONT RANGE
AND INTO THE CENTRAL MS VALLEY AND THROUGH EASTERN KENTUCKY BY
THURSDAY MORNING. AT THIS TIME...ENOUGH OF THE COLDER AIR MAY STILL
BE IN PLACE FOR THIS PRECIP TO BEGIN AS SNOW. IN FACT...THIS COULD
BE THE FIRST INCH OF SNOWFALL FOR MANY PLACES...IF TRENDS KEEP THE
COLDER AIR IN PLACE. THE SUPER BLEND KEEP AT LEAST CHANCE POPS OVER
THE AREA FOR THE WEDNESDAY THROUGH THURSDAY PERIOD AS SOME UPSLOPE
IS POSSIBLE BEHIND THIS FRONT. MODELS AS WELL...HAVE TRENDED ENOUGH
MOISTURE ASSOCIATED WITH THIS FEATURE TO KEEP SNOW IN THE FORECAST.
WILL NEED TO MONITOR FOR ANY CHANGES IN THE TRENDS CONCERNING THIS
FEATURE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 110 PM EST FRI JAN 15 2016
RAIN WILL MOVE THROUGH THE FAR SOUTHEAST PART OF THE FORECAST AREA
THIS AFTERNOON...WITH THE STEADY RAIN THEN EXITING INTO WV BY
AROUND 23Z. MEANWHILE... ANOTHER AREA OF RAIN ASSOCIATED WITH A
COLD FRONT OVER CENTRAL KY AT MID DAY WILL MOVE EAST. THIS WILL
MOVE THROUGH THE JKL FORECAST AREA FROM ABOUT 22Z-03Z...
DISSIPATING AT THE SAME TIME. ONCE THE COLD FRONT MOVES THROUGH
THIS EVENING...DRIZZLE WILL BE POSSIBLE AT TIMES THROUGH THE
REMAINDER OF THE PERIOD...AND SOME FLURRIES OR EVEN FREEZING
DRIZZLE CAN NOT BE RULED OUT AS TEMPERATURES FALL TO NEAR FREEZING
AROUND DAWN.
CONDITIONS SHOULD LARGELY BE VFR UNTIL EARLY THIS EVENING...WITH
THE EXCEPTION OF SOME MVFR NEAR THE VA BORDER. AS THE COLD FRONT
MOVES THROUGH THIS EVENING...CONDITIONS ARE EXPECTED TO
DETERIORATE TO IFR AND REMAIN THERE THROUGH MOST OF THE REMAINDER
OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...SHALLENBERGER
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
132 PM EST FRI JAN 15 2016
.UPDATE...
ISSUED AT 132 PM EST FRI JAN 15 2016
RAIN FROM SE SYSTEM HAS PROGRESS AS FAR NW AS KJKL...AND HAVE
UPDATED WITH HIGHER AFTERNOON POPS OVER THE SE PART OF THE AREA.
UPDATE ISSUED AT 1157 AM EST FRI JAN 15 2016
SYSTEM MOVING THROUGH THE SE CONUS WILL END UP HAVING A GREATER
INFLUENCE ON OUR LOCAL AREA THAN EARLIER FORECAST. RAIN IS
SPREADING INTO OUR FAR SOUTHEAST COUNTIES...AND POPS HAVE BEEN
RAISED THERE FOR TODAY. WET BULB TEMPERATURES OVER THE HIGH
ELEVATIONS NEAR THE VA BORDER ARE BELOW FREEZING...AND THIS COULD
ALLOW FOR SOME SNOW TO INITIALLY OCCUR AS PRECIP MOVES IN...BUT IT
SHOULD FADE AWAY AS WET BULB READINGS EVENTUALLY RISE.
MEANWHILE... PRECIP OVER CENTRAL KY AHEAD OF A COLD FRONT HAS BEEN
SLOWER TO MAKE ITS WAY EAST THAN WAS EXPECTED...AND HAVE LOWERED
POPS TODAY AND HELD PRECIP OFF LONGER IN THE NW PART OF THE AREA.
WHAT IS LEFT OF THE FRONTAL PRECIP WILL MAKE ITS WAY ACROSS THE
REMAINDER OF OUR AREA...ESPECIALLY THE NORTH...THIS EVENING.
BEHIND THE COLD FRONT...POTENTIAL FOR PRECIP AND ITS TYPE REMAIN
ISSUES. MOISTURE WILL BE SHALLOW AND MAY NOT REACH -10C FOR ICE
FORMATION. HOWEVER...SURFACE TEMPS SHOULD EVENTUALLY REACH
FREEZING FOR SOME LOCATIONS. PRECIP TYPE COULD END UP BEING
DRIZZLE...FREEZING DRIZZLE...FLURRIES...OR SOME COMBINATION. AT
THIS POINT...HAVE ONLY USED SLIGHT CHANCE WORDING FOR THE
NONMEASURABLE PRECIP FROM LATE TONIGHT INTO SATURDAY NIGHT.
UPDATE ISSUED AT 751 AM EST FRI JAN 15 2016
FRESHENED UP THE HOURLY TEMPERATURES AND DEW POINTS. SHELTERED
VALLEYS ARE RANGING FROM THE MID 20S TO THE LOWER 30S...WITH MOST
OTHER LOCATIONS REPORTING IN THE LOW TO MID 40S. THICKER CLOUDS
ARE STARTING TO OVERTAKE THE AREA...WITH RAIN SHOWERS MOVING IN
ACROSS PORTIONS OF WESTERN KENTUCKY. THE LATEST HRRR GUIDANCE
CONTINUES TO SHOW LITTLE IN THE WAY OF SHOWER ACTIVITY UNTIL THIS
AFTERNOON...WHEN THE FAR SOUTHEAST MAY GET BRUSHED. WILL LET THE
CURRENT FORECAST RIDE FOR NOW. GRID UPDATES WILL BE FORTHCOMING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
SURFACE LOW PRESSURE IS CURRENTLY CRUISING TOWARDS THE GREAT
LAKES...WITH AN ATTENDANT COLD FRONT ALIGNED SOUTHWEST THROUGH THE
SOUTHERN PLAINS. ANOTHER LOW PRESSURE SYSTEM IS ORGANIZING ACROSS
THE NORTH CENTRAL GULF OF MEXICO...WITH HIGH PRESSURE RETREATING
OFF THE CAROLINA COAST. ALOFT...A SHORT WAVE TROUGH IS MOVING
ACROSS THE PLAINS WITHIN THE NORTHERN STREAM...WHILE ANOTHER ONE
IS MOVING THROUGH THE NORTH CENTRAL GULF WITHIN THE SOUTHERN
STREAM. THIS IS ALLOWING FOR DEEPER SOUTHWEST FLOW ACROSS THE MID
AND LOWER MISSISSIPPI VALLEY...WITH PLENTY OF HIGH CLOUDS
STREAMING IN FROM THE SOUTHWEST. EASTERN KENTUCKY REMAINS UNDER
PARTLY CLOUDY TO MOSTLY CLEAR SKIES...WITH TEMPERATURES VARYING
FROM THE MID TO UPPER 40S IN THE BROADER VALLEYS AND
RIDGETOPS...WHILE SHELTERED VALLEYS IN THE EAST REMAIN SOME 20
DEGREES COLDER...IN THE MID TO UPPER 20S.
THE TWO AFOREMENTIONED SYSTEMS WILL TRACK EAST TODAY...WITH
EASTERN KENTUCKY REMAINING SPLIT BETWEEN THEM. THE MODELS HAVE
TRENDED A BIT DRIER WITH THE SOUTHERN STREAM MOISTURE...KEEPING
MOST OF THIS JUST TO OUR SOUTHEAST. MOST OF THE FORCING WILL COME
FROM THE NORTHERN STREAM SYSTEM AS THE TROUGH AXIS AND SURFACE
COLD FRONT APPROACH FROM THE WEST. LIGHT RAIN SHOWERS WILL MOVE IN
FROM THE WEST TODAY...WITH THE MAJORITY OF THE ACTIVITY HOLDING
OFF UNTIL THIS AFTERNOON. THE BEST OVERALL RAIN CHANCES STILL LOOK
TO OCCUR IN THE FAR WEST...WITH LESSER CHANCES IN OUR NORTHEAST
COUNTIES. HIGHS TODAY WILL RECOVER INTO THE LOW TO MID 50S...WITH
SOME SPOTS REACHING THE UPPER 50S IN THE EAST...WHERE THICKER
CLOUD COVER WILL HOLD OFF THE LONGEST.
THE COLD FRONT AND TROUGH AXIS WILL SWING THROUGH THE AREA BETWEEN
00 AND 06Z TONIGHT...WITH A GOOD CHANCE OF LIGHT PRECIPITATION
CONTINUING. COLD ADVECTION WILL BE UNDERWAY OVERNIGHT...WITH LOWS
FOR MOST COOLING OFF TO THE LOW TO MID 30S. THE ONLY EXCEPTION
WILL BE THE HIGHER TERRAIN...WHERE LOWS WILL SETTLE INTO THE 20S.
HAVE LEFT A MENTION OF SNOW IN THE FORECAST TOWARDS DAWN SATURDAY
MORNING...HOWEVER WITH ICE IN QUESTION...DRIZZLE AND OR FREEZING
DRIZZLE MAY BECOME A CONCERN FOR THE HIGHER ELEVATIONS.
ANY LIGHT PRECIPITATION LINGERING INTO SATURDAY WILL TAPER OFF
DURING THE DAY AS FORCING DIMINISHES. HIGH TEMPERATURES WILL NOT
RECOVER MUCH DURING THE DAY WITH THICK CLOUD COVER LOCKED INTO
PLACE THANKS TO A POST-FRONTAL INVERSION. HAVE UNDERCUT THE
BLENDED GUIDANCE FOR THE HIGHS...ONLY ALLOWING FOR A FEW DEGREE
OR SO RISE FROM SATURDAY MORNING LOWS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
...COLDEST AIR OF SEASON LIKELY SUNDAY NIGHT THROUGH MONDAY NIGHT...
MODELS REMAIN IN DECENT AGREEMENT ON THE MID/UPPER LEVEL PATTERN
THROUGH TUESDAY...BUT REMAIN FARTHER APART FROM WEDNESDAY ONWARD.
THE MAIN HEADLINE THROUGH THE EXTENDED WILL BE THE ARCTIC COLD FOR
EARLY NEXT WEEK.
SATURDAY NIGHT INTO SUNDAY...A QUICK MOVING SHORTWAVE TROUGH WILL
CROSS THE SOUTHERN APPALACHIANS AND COULD SEND SOME LIGHT SNOW
ACROSS SOUTHEAST KENTUCKY EARLY SUNDAY MORNING. STILL SOME QUESTION
ON HOW FAR BACK TO THE NORTHWEST THE SNOWFALL EXTENDS...BUT OUR
COUNTIES BORDERING VIRGINIA STAND A DECENT CHANCE TO SEE SOME LIGHT
SNOW AND POTENTIALLY A LIGHT COATING OF SNOW. THIS SYSTEM WILL BE
FASTER MOVING...SO SNOW CHANCES WILL QUICKLY DIMINISH SUNDAY
MORNING WITH CLOUDS POSSIBLY PARTING WAYS BY LATE MORNING INTO THE
AFTERNOON. WITH SOME SUNSHINE...CERTAINLY POSSIBLE HIGHS WILL MAKE
A BOUNCE UP IN TO THE MID TO UPPER 30S.
AN ARCTIC FRONT WILL THEN DROP SOUTH SUNDAY EVENING WITH COLD AIR
SURGING ACROSS KENTUCKY. LOWS BY MONDAY MORNING WILL BE WELL INTO
THE TEENS AND WE MAY NOT SEE TEMPERATURES CLIMB MUCH AT ALL ON
MONDAY. MOISTURE WITH THE FRONT REMAINS VERY LIMITED...AND
WOULDN`T EXPECT MORE THAN SOME FLURRIES WITH THE FRONTAL PASSAGE.
GIVEN THE COLD AIR...WE COULD MAINTAIN SOME FLURRIES WELL INTO
MONDAY MORNING...EVEN WITH THE LACK OF DECENT CLOUD COVER.
SHOULDN`T TAKE MUCH WITH USPLOPE FLOW TO SQUEEZE OUT FLURRIES IN
THIS COLD AIR MASS. BY MONDAY NIGHT...HIGH PRESSURE WILL BUILD
INTO THE REGION WITH LOWS FALLING TO AROUND ZERO IN THE
VALLEYS...SETTING UP THE COLDEST NIGHT THUS FAR THIS WINTER. WITH
THE HELP OF SUNSHINE ON TUESDAY WE SHOULD SEE TEMPERATURES CLIMB
BACK INTO THE 20S.
00Z ECMWF TRENDED SLIGHTLY TOWARDS THE GFS SOLUTION OF A CLIPPER
SYSTEM FOR WEDNESDAY. THIS WOULD SUPPORT SOME LIGHT SNOW
OVERSPREADING THE AREA ON WEDNESDAY WITH SOME LIGHT SNOW
ACCUMULATIONS POSSIBLE. TEMPERATURES MAY CREEP ABOVE FREEZING ON
WEDNESDAY...BUT ANY PRECIPITATION WILL REMAIN ALL SNOW BASED ON THE
TOP DOWN METHOD ON THE SOUNDING. WITH THE ECMWF TRENDING TOWARDS THE
GFS...WE MAY DRY THINGS OUT LATE WEDNESDAY NIGHT INTO THURSDAY
BEFORE ANOTHER SYSTEM POSSIBLY MOVES INTO THE REGION LATE IN THE
WEEK. REGARDLESS...MODELS STILL REMAIN FAR APART...SO WILL JUST
BRING IN SOME SLIGHT CHANCE POPS TOWARDS THE TAIL END OF THE
FORECAST AND LEAVE THEM FAIRLY LOW WITH THIS DEGREE OF LOW
CONFIDENCE. IT DOES APPEAR TEMPERATURES SHOULD WARM LATE IN THE
WEEK...SUPPORTING AN ALL RAIN EVENT IF A SYSTEM DOES MATERIALIZE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 110 PM EST FRI JAN 15 2016
RAIN WILL MOVE THROUGH THE FAR SOUTHEAST PART OF THE FORECAST AREA
THIS AFTERNOON...WITH THE STEADY RAIN THEN EXITING INTO WV BY
AROUND 23Z. MEANWHILE... ANOTHER AREA OF RAIN ASSOCIATED WITH A
COLD FRONT OVER CENTRAL KY AT MID DAY WILL MOVE EAST. THIS WILL
MOVE THROUGH THE JKL FORECAST AREA FROM ABOUT 22Z-03Z...
DISSIPATING AT THE SAME TIME. ONCE THE COLD FRONT MOVES THROUGH
THIS EVENING...DRIZZLE WILL BE POSSIBLE AT TIMES THROUGH THE
REMAINDER OF THE PERIOD...AND SOME FLURRIES OR EVEN FREEZING
DRIZZLE CAN NOT BE RULED OUT AS TEMPERATURES FALL TO NEAR FREEZING
AROUND DAWN.
CONDITIONS SHOULD LARGELY BE VFR UNTIL EARLY THIS EVENING...WITH
THE EXCEPTION OF SOME MVFR NEAR THE VA BORDER. AS THE COLD FRONT
MOVES THROUGH THIS EVENING...CONDITIONS ARE EXPECTED TO
DETERIORATE TO IFR AND REMAIN THERE THROUGH MOST OF THE REMAINDER
OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
110 PM EST FRI JAN 15 2016
.UPDATE...
ISSUED AT 1157 AM EST FRI JAN 15 2016
SYSTEM MOVING THROUGH THE SE CONUS WILL END UP HAVING A GREATER
INFLUENCE ON OUR LOCAL AREA THAN EARLIER FORECAST. RAIN IS
SPREADING INTO OUR FAR SOUTHEAST COUNTIES...AND POPS HAVE BEEN
RAISED THERE FOR TODAY. WET BULB TEMPERATURES OVER THE HIGH
ELEVATIONS NEAR THE VA BORDER ARE BELOW FREEZING...AND THIS COULD
ALLOW FOR SOME SNOW TO INITIALLY OCCUR AS PRECIP MOVES IN...BUT IT
SHOULD FADE AWAY AS WET BULB READINGS EVENTUALLY RISE.
MEANWHILE... PRECIP OVER CENTRAL KY AHEAD OF A COLD FRONT HAS BEEN
SLOWER TO MAKE ITS WAY EAST THAN WAS EXPECTED...AND HAVE LOWERED
POPS TODAY AND HELD PRECIP OFF LONGER IN THE NW PART OF THE AREA.
WHAT IS LEFT OF THE FRONTAL PRECIP WILL MAKE ITS WAY ACROSS THE
REMAINDER OF OUR AREA...ESPECIALLY THE NORTH...THIS EVENING.
BEHIND THE COLD FRONT...POTENTIAL FOR PRECIP AND ITS TYPE REMAIN
ISSUES. MOISTURE WILL BE SHALLOW AND MAY NOT REACH -10C FOR ICE
FORMATION. HOWEVER...SURFACE TEMPS SHOULD EVENTUALLY REACH
FREEZING FOR SOME LOCATIONS. PRECIP TYPE COULD END UP BEING
DRIZZLE...FREEZING DRIZZLE...FLURRIES...OR SOME COMBINATION. AT
THIS POINT...HAVE ONLY USED SLIGHT CHANCE WORDING FOR THE
NONMEASURABLE PRECIP FROM LATE TONIGHT INTO SATURDAY NIGHT.
UPDATE ISSUED AT 751 AM EST FRI JAN 15 2016
FRESHENED UP THE HOURLY TEMPERATURES AND DEW POINTS. SHELTERED
VALLEYS ARE RANGING FROM THE MID 20S TO THE LOWER 30S...WITH MOST
OTHER LOCATIONS REPORTING IN THE LOW TO MID 40S. THICKER CLOUDS
ARE STARTING TO OVERTAKE THE AREA...WITH RAIN SHOWERS MOVING IN
ACROSS PORTIONS OF WESTERN KENTUCKY. THE LATEST HRRR GUIDANCE
CONTINUES TO SHOW LITTLE IN THE WAY OF SHOWER ACTIVITY UNTIL THIS
AFTERNOON...WHEN THE FAR SOUTHEAST MAY GET BRUSHED. WILL LET THE
CURRENT FORECAST RIDE FOR NOW. GRID UPDATES WILL BE FORTHCOMING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
SURFACE LOW PRESSURE IS CURRENTLY CRUISING TOWARDS THE GREAT
LAKES...WITH AN ATTENDANT COLD FRONT ALIGNED SOUTHWEST THROUGH THE
SOUTHERN PLAINS. ANOTHER LOW PRESSURE SYSTEM IS ORGANIZING ACROSS
THE NORTH CENTRAL GULF OF MEXICO...WITH HIGH PRESSURE RETREATING
OFF THE CAROLINA COAST. ALOFT...A SHORT WAVE TROUGH IS MOVING
ACROSS THE PLAINS WITHIN THE NORTHERN STREAM...WHILE ANOTHER ONE
IS MOVING THROUGH THE NORTH CENTRAL GULF WITHIN THE SOUTHERN
STREAM. THIS IS ALLOWING FOR DEEPER SOUTHWEST FLOW ACROSS THE MID
AND LOWER MISSISSIPPI VALLEY...WITH PLENTY OF HIGH CLOUDS
STREAMING IN FROM THE SOUTHWEST. EASTERN KENTUCKY REMAINS UNDER
PARTLY CLOUDY TO MOSTLY CLEAR SKIES...WITH TEMPERATURES VARYING
FROM THE MID TO UPPER 40S IN THE BROADER VALLEYS AND
RIDGETOPS...WHILE SHELTERED VALLEYS IN THE EAST REMAIN SOME 20
DEGREES COLDER...IN THE MID TO UPPER 20S.
THE TWO AFOREMENTIONED SYSTEMS WILL TRACK EAST TODAY...WITH
EASTERN KENTUCKY REMAINING SPLIT BETWEEN THEM. THE MODELS HAVE
TRENDED A BIT DRIER WITH THE SOUTHERN STREAM MOISTURE...KEEPING
MOST OF THIS JUST TO OUR SOUTHEAST. MOST OF THE FORCING WILL COME
FROM THE NORTHERN STREAM SYSTEM AS THE TROUGH AXIS AND SURFACE
COLD FRONT APPROACH FROM THE WEST. LIGHT RAIN SHOWERS WILL MOVE IN
FROM THE WEST TODAY...WITH THE MAJORITY OF THE ACTIVITY HOLDING
OFF UNTIL THIS AFTERNOON. THE BEST OVERALL RAIN CHANCES STILL LOOK
TO OCCUR IN THE FAR WEST...WITH LESSER CHANCES IN OUR NORTHEAST
COUNTIES. HIGHS TODAY WILL RECOVER INTO THE LOW TO MID 50S...WITH
SOME SPOTS REACHING THE UPPER 50S IN THE EAST...WHERE THICKER
CLOUD COVER WILL HOLD OFF THE LONGEST.
THE COLD FRONT AND TROUGH AXIS WILL SWING THROUGH THE AREA BETWEEN
00 AND 06Z TONIGHT...WITH A GOOD CHANCE OF LIGHT PRECIPITATION
CONTINUING. COLD ADVECTION WILL BE UNDERWAY OVERNIGHT...WITH LOWS
FOR MOST COOLING OFF TO THE LOW TO MID 30S. THE ONLY EXCEPTION
WILL BE THE HIGHER TERRAIN...WHERE LOWS WILL SETTLE INTO THE 20S.
HAVE LEFT A MENTION OF SNOW IN THE FORECAST TOWARDS DAWN SATURDAY
MORNING...HOWEVER WITH ICE IN QUESTION...DRIZZLE AND OR FREEZING
DRIZZLE MAY BECOME A CONCERN FOR THE HIGHER ELEVATIONS.
ANY LIGHT PRECIPITATION LINGERING INTO SATURDAY WILL TAPER OFF
DURING THE DAY AS FORCING DIMINISHES. HIGH TEMPERATURES WILL NOT
RECOVER MUCH DURING THE DAY WITH THICK CLOUD COVER LOCKED INTO
PLACE THANKS TO A POST-FRONTAL INVERSION. HAVE UNDERCUT THE
BLENDED GUIDANCE FOR THE HIGHS...ONLY ALLOWING FOR A FEW DEGREE
OR SO RISE FROM SATURDAY MORNING LOWS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
...COLDEST AIR OF SEASON LIKELY SUNDAY NIGHT THROUGH MONDAY NIGHT...
MODELS REMAIN IN DECENT AGREEMENT ON THE MID/UPPER LEVEL PATTERN
THROUGH TUESDAY...BUT REMAIN FARTHER APART FROM WEDNESDAY ONWARD.
THE MAIN HEADLINE THROUGH THE EXTENDED WILL BE THE ARCTIC COLD FOR
EARLY NEXT WEEK.
SATURDAY NIGHT INTO SUNDAY...A QUICK MOVING SHORTWAVE TROUGH WILL
CROSS THE SOUTHERN APPALACHIANS AND COULD SEND SOME LIGHT SNOW
ACROSS SOUTHEAST KENTUCKY EARLY SUNDAY MORNING. STILL SOME QUESTION
ON HOW FAR BACK TO THE NORTHWEST THE SNOWFALL EXTENDS...BUT OUR
COUNTIES BORDERING VIRGINIA STAND A DECENT CHANCE TO SEE SOME LIGHT
SNOW AND POTENTIALLY A LIGHT COATING OF SNOW. THIS SYSTEM WILL BE
FASTER MOVING...SO SNOW CHANCES WILL QUICKLY DIMINISH SUNDAY
MORNING WITH CLOUDS POSSIBLY PARTING WAYS BY LATE MORNING INTO THE
AFTERNOON. WITH SOME SUNSHINE...CERTAINLY POSSIBLE HIGHS WILL MAKE
A BOUNCE UP IN TO THE MID TO UPPER 30S.
AN ARCTIC FRONT WILL THEN DROP SOUTH SUNDAY EVENING WITH COLD AIR
SURGING ACROSS KENTUCKY. LOWS BY MONDAY MORNING WILL BE WELL INTO
THE TEENS AND WE MAY NOT SEE TEMPERATURES CLIMB MUCH AT ALL ON
MONDAY. MOISTURE WITH THE FRONT REMAINS VERY LIMITED...AND
WOULDN`T EXPECT MORE THAN SOME FLURRIES WITH THE FRONTAL PASSAGE.
GIVEN THE COLD AIR...WE COULD MAINTAIN SOME FLURRIES WELL INTO
MONDAY MORNING...EVEN WITH THE LACK OF DECENT CLOUD COVER.
SHOULDN`T TAKE MUCH WITH USPLOPE FLOW TO SQUEEZE OUT FLURRIES IN
THIS COLD AIR MASS. BY MONDAY NIGHT...HIGH PRESSURE WILL BUILD
INTO THE REGION WITH LOWS FALLING TO AROUND ZERO IN THE
VALLEYS...SETTING UP THE COLDEST NIGHT THUS FAR THIS WINTER. WITH
THE HELP OF SUNSHINE ON TUESDAY WE SHOULD SEE TEMPERATURES CLIMB
BACK INTO THE 20S.
00Z ECMWF TRENDED SLIGHTLY TOWARDS THE GFS SOLUTION OF A CLIPPER
SYSTEM FOR WEDNESDAY. THIS WOULD SUPPORT SOME LIGHT SNOW
OVERSPREADING THE AREA ON WEDNESDAY WITH SOME LIGHT SNOW
ACCUMULATIONS POSSIBLE. TEMPERATURES MAY CREEP ABOVE FREEZING ON
WEDNESDAY...BUT ANY PRECIPITATION WILL REMAIN ALL SNOW BASED ON THE
TOP DOWN METHOD ON THE SOUNDING. WITH THE ECMWF TRENDING TOWARDS THE
GFS...WE MAY DRY THINGS OUT LATE WEDNESDAY NIGHT INTO THURSDAY
BEFORE ANOTHER SYSTEM POSSIBLY MOVES INTO THE REGION LATE IN THE
WEEK. REGARDLESS...MODELS STILL REMAIN FAR APART...SO WILL JUST
BRING IN SOME SLIGHT CHANCE POPS TOWARDS THE TAIL END OF THE
FORECAST AND LEAVE THEM FAIRLY LOW WITH THIS DEGREE OF LOW
CONFIDENCE. IT DOES APPEAR TEMPERATURES SHOULD WARM LATE IN THE
WEEK...SUPPORTING AN ALL RAIN EVENT IF A SYSTEM DOES MATERIALIZE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 110 PM EST FRI JAN 15 2016
RAIN WILL MOVE THROUGH THE FAR SOUTHEAST PART OF THE FORECAST AREA
THIS AFTERNOON...WITH THE STEADY RAIN THEN EXITING INTO WV BY
AROUND 23Z. MEANWHILE... ANOTHER AREA OF RAIN ASSOCIATED WITH A
COLD FRONT OVER CENTRAL KY AT MID DAY WILL MOVE EAST. THIS WILL
MOVE THROUGH THE JKL FORECAST AREA FROM ABOUT 22Z-03Z...
DISSIPATING AT THE SAME TIME. ONCE THE COLD FRONT MOVES THROUGH
THIS EVENING...DRIZZLE WILL BE POSSIBLE AT TIMES THROUGH THE
REMAINDER OF THE PERIOD...AND SOME FLURRIES OR EVEN FREEZING
DRIZZLE CAN NOT BE RULED OUT AS TEMPERATURES FALL TO NEAR FREEZING
AROUND DAWN.
CONDITIONS SHOULD LARGELY BE VFR UNTIL EARLY THIS EVENING...WITH
THE EXCEPTION OF SOME MVFR NEAR THE VA BORDER. AS THE COLD FRONT
MOVES THROUGH THIS EVENING...CONDITIONS ARE EXPECTED TO
DETERIORATE TO IFR AND REMAIN THERE THROUGH MOST OF THE REMAINDER
OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1157 AM EST FRI JAN 15 2016
.UPDATE...
ISSUED AT 1157 AM EST FRI JAN 15 2016
SYSTEM MOVING THROUGH THE SE CONUS WILL END UP HAVING A GREATER
INFLUENCE ON OUR LOCAL AREA THAN EARLIER FORECAST. RAIN IS
SPREADING INTO OUR FAR SOUTHEAST COUNTIES...AND POPS HAVE BEEN
RAISED THERE FOR TODAY. WET BULB TEMPERATURES OVER THE HIGH
ELEVATIONS NEAR THE VA BORDER ARE BELOW FREEZING...AND THIS COULD
ALLOW FOR SOME SNOW TO INITIALLY OCCUR AS PRECIP MOVES IN...BUT IT
SHOULD FADE AWAY AS WET BULB READINGS EVENTUALLY RISE.
MEANWHILE... PRECIP OVER CENTRAL KY AHEAD OF A COLD FRONT HAS BEEN
SLOWER TO MAKE ITS WAY EAST THAN WAS EXPECTED...AND HAVE LOWERED
POPS TODAY AND HELD PRECIP OFF LONGER IN THE NW PART OF THE AREA.
WHAT IS LEFT OF THE FRONTAL PRECIP WILL MAKE ITS WAY ACROSS THE
REMAINDER OF OUR AREA...ESPECIALLY THE NORTH...THIS EVENING.
BEHIND THE COLD FRONT...POTENTIAL FOR PRECIP AND ITS TYPE REMAIN
ISSUES. MOISTURE WILL BE SHALLOW AND MAY NOT REACH -10C FOR ICE
FORMATION. HOWEVER...SURFACE TEMPS SHOULD EVENTUALLY REACH
FREEZING FOR SOME LOCATIONS. PRECIP TYPE COULD END UP BEING
DRIZZLE...FREEZING DRIZZLE...FLURRIES...OR SOME COMBINATION. AT
THIS POINT...HAVE ONLY USED SLIGHT CHANCE WORDING FOR THE
NONMEASURABLE PRECIP FROM LATE TONIGHT INTO SATURDAY NIGHT.
UPDATE ISSUED AT 751 AM EST FRI JAN 15 2016
FRESHENED UP THE HOURLY TEMPERATURES AND DEW POINTS. SHELTERED
VALLEYS ARE RANGING FROM THE MID 20S TO THE LOWER 30S...WITH MOST
OTHER LOCATIONS REPORTING IN THE LOW TO MID 40S. THICKER CLOUDS
ARE STARTING TO OVERTAKE THE AREA...WITH RAIN SHOWERS MOVING IN
ACROSS PORTIONS OF WESTERN KENTUCKY. THE LATEST HRRR GUIDANCE
CONTINUES TO SHOW LITTLE IN THE WAY OF SHOWER ACTIVITY UNTIL THIS
AFTERNOON...WHEN THE FAR SOUTHEAST MAY GET BRUSHED. WILL LET THE
CURRENT FORECAST RIDE FOR NOW. GRID UPDATES WILL BE FORTHCOMING.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
SURFACE LOW PRESSURE IS CURRENTLY CRUISING TOWARDS THE GREAT
LAKES...WITH AN ATTENDANT COLD FRONT ALIGNED SOUTHWEST THROUGH THE
SOUTHERN PLAINS. ANOTHER LOW PRESSURE SYSTEM IS ORGANIZING ACROSS
THE NORTH CENTRAL GULF OF MEXICO...WITH HIGH PRESSURE RETREATING
OFF THE CAROLINA COAST. ALOFT...A SHORT WAVE TROUGH IS MOVING
ACROSS THE PLAINS WITHIN THE NORTHERN STREAM...WHILE ANOTHER ONE
IS MOVING THROUGH THE NORTH CENTRAL GULF WITHIN THE SOUTHERN
STREAM. THIS IS ALLOWING FOR DEEPER SOUTHWEST FLOW ACROSS THE MID
AND LOWER MISSISSIPPI VALLEY...WITH PLENTY OF HIGH CLOUDS
STREAMING IN FROM THE SOUTHWEST. EASTERN KENTUCKY REMAINS UNDER
PARTLY CLOUDY TO MOSTLY CLEAR SKIES...WITH TEMPERATURES VARYING
FROM THE MID TO UPPER 40S IN THE BROADER VALLEYS AND
RIDGETOPS...WHILE SHELTERED VALLEYS IN THE EAST REMAIN SOME 20
DEGREES COLDER...IN THE MID TO UPPER 20S.
THE TWO AFOREMENTIONED SYSTEMS WILL TRACK EAST TODAY...WITH
EASTERN KENTUCKY REMAINING SPLIT BETWEEN THEM. THE MODELS HAVE
TRENDED A BIT DRIER WITH THE SOUTHERN STREAM MOISTURE...KEEPING
MOST OF THIS JUST TO OUR SOUTHEAST. MOST OF THE FORCING WILL COME
FROM THE NORTHERN STREAM SYSTEM AS THE TROUGH AXIS AND SURFACE
COLD FRONT APPROACH FROM THE WEST. LIGHT RAIN SHOWERS WILL MOVE IN
FROM THE WEST TODAY...WITH THE MAJORITY OF THE ACTIVITY HOLDING
OFF UNTIL THIS AFTERNOON. THE BEST OVERALL RAIN CHANCES STILL LOOK
TO OCCUR IN THE FAR WEST...WITH LESSER CHANCES IN OUR NORTHEAST
COUNTIES. HIGHS TODAY WILL RECOVER INTO THE LOW TO MID 50S...WITH
SOME SPOTS REACHING THE UPPER 50S IN THE EAST...WHERE THICKER
CLOUD COVER WILL HOLD OFF THE LONGEST.
THE COLD FRONT AND TROUGH AXIS WILL SWING THROUGH THE AREA BETWEEN
00 AND 06Z TONIGHT...WITH A GOOD CHANCE OF LIGHT PRECIPITATION
CONTINUING. COLD ADVECTION WILL BE UNDERWAY OVERNIGHT...WITH LOWS
FOR MOST COOLING OFF TO THE LOW TO MID 30S. THE ONLY EXCEPTION
WILL BE THE HIGHER TERRAIN...WHERE LOWS WILL SETTLE INTO THE 20S.
HAVE LEFT A MENTION OF SNOW IN THE FORECAST TOWARDS DAWN SATURDAY
MORNING...HOWEVER WITH ICE IN QUESTION...DRIZZLE AND OR FREEZING
DRIZZLE MAY BECOME A CONCERN FOR THE HIGHER ELEVATIONS.
ANY LIGHT PRECIPITATION LINGERING INTO SATURDAY WILL TAPER OFF
DURING THE DAY AS FORCING DIMINISHES. HIGH TEMPERATURES WILL NOT
RECOVER MUCH DURING THE DAY WITH THICK CLOUD COVER LOCKED INTO
PLACE THANKS TO A POST-FRONTAL INVERSION. HAVE UNDERCUT THE
BLENDED GUIDANCE FOR THE HIGHS...ONLY ALLOWING FOR A FEW DEGREE
OR SO RISE FROM SATURDAY MORNING LOWS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 344 AM EST FRI JAN 15 2016
...COLDEST AIR OF SEASON LIKELY SUNDAY NIGHT THROUGH MONDAY NIGHT...
MODELS REMAIN IN DECENT AGREEMENT ON THE MID/UPPER LEVEL PATTERN
THROUGH TUESDAY...BUT REMAIN FARTHER APART FROM WEDNESDAY ONWARD.
THE MAIN HEADLINE THROUGH THE EXTENDED WILL BE THE ARCTIC COLD FOR
EARLY NEXT WEEK.
SATURDAY NIGHT INTO SUNDAY...A QUICK MOVING SHORTWAVE TROUGH WILL
CROSS THE SOUTHERN APPALACHIANS AND COULD SEND SOME LIGHT SNOW
ACROSS SOUTHEAST KENTUCKY EARLY SUNDAY MORNING. STILL SOME QUESTION
ON HOW FAR BACK TO THE NORTHWEST THE SNOWFALL EXTENDS...BUT OUR
COUNTIES BORDERING VIRGINIA STAND A DECENT CHANCE TO SEE SOME LIGHT
SNOW AND POTENTIALLY A LIGHT COATING OF SNOW. THIS SYSTEM WILL BE
FASTER MOVING...SO SNOW CHANCES WILL QUICKLY DIMINISH SUNDAY
MORNING WITH CLOUDS POSSIBLY PARTING WAYS BY LATE MORNING INTO THE
AFTERNOON. WITH SOME SUNSHINE...CERTAINLY POSSIBLE HIGHS WILL MAKE
A BOUNCE UP IN TO THE MID TO UPPER 30S.
AN ARCTIC FRONT WILL THEN DROP SOUTH SUNDAY EVENING WITH COLD AIR
SURGING ACROSS KENTUCKY. LOWS BY MONDAY MORNING WILL BE WELL INTO
THE TEENS AND WE MAY NOT SEE TEMPERATURES CLIMB MUCH AT ALL ON
MONDAY. MOISTURE WITH THE FRONT REMAINS VERY LIMITED...AND
WOULDN`T EXPECT MORE THAN SOME FLURRIES WITH THE FRONTAL PASSAGE.
GIVEN THE COLD AIR...WE COULD MAINTAIN SOME FLURRIES WELL INTO
MONDAY MORNING...EVEN WITH THE LACK OF DECENT CLOUD COVER.
SHOULDN`T TAKE MUCH WITH USPLOPE FLOW TO SQUEEZE OUT FLURRIES IN
THIS COLD AIR MASS. BY MONDAY NIGHT...HIGH PRESSURE WILL BUILD
INTO THE REGION WITH LOWS FALLING TO AROUND ZERO IN THE
VALLEYS...SETTING UP THE COLDEST NIGHT THUS FAR THIS WINTER. WITH
THE HELP OF SUNSHINE ON TUESDAY WE SHOULD SEE TEMPERATURES CLIMB
BACK INTO THE 20S.
00Z ECMWF TRENDED SLIGHTLY TOWARDS THE GFS SOLUTION OF A CLIPPER
SYSTEM FOR WEDNESDAY. THIS WOULD SUPPORT SOME LIGHT SNOW
OVERSPREADING THE AREA ON WEDNESDAY WITH SOME LIGHT SNOW
ACCUMULATIONS POSSIBLE. TEMPERATURES MAY CREEP ABOVE FREEZING ON
WEDNESDAY...BUT ANY PRECIPITATION WILL REMAIN ALL SNOW BASED ON THE
TOP DOWN METHOD ON THE SOUNDING. WITH THE ECMWF TRENDING TOWARDS THE
GFS...WE MAY DRY THINGS OUT LATE WEDNESDAY NIGHT INTO THURSDAY
BEFORE ANOTHER SYSTEM POSSIBLY MOVES INTO THE REGION LATE IN THE
WEEK. REGARDLESS...MODELS STILL REMAIN FAR APART...SO WILL JUST
BRING IN SOME SLIGHT CHANCE POPS TOWARDS THE TAIL END OF THE
FORECAST AND LEAVE THEM FAIRLY LOW WITH THIS DEGREE OF LOW
CONFIDENCE. IT DOES APPEAR TEMPERATURES SHOULD WARM LATE IN THE
WEEK...SUPPORTING AN ALL RAIN EVENT IF A SYSTEM DOES MATERIALIZE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 751 AM EST FRI JAN 15 2016
VFR CONDITIONS WILL HOLD ON THROUGH EARLY THIS AFTERNOON...WITH
MAINLY JUST PASSING HIGH CLOUDS TO CONTEND WITH UNTIL AFTER 18Z.
CEILINGS WILL THEN LOWER MORE QUICKLY DOWN TO MVFR FROM WEST TO
EAST...BETWEEN 21Z AND 00Z SATURDAY...WITH LIGHT RAIN SHOWERS
MOVING IN FROM THE WEST. A COLD FRONT WILL PASS THROUGH THIS
EVENING...WITH CEILINGS DROPPING DOWN TO IFR BEHIND THE BOUNDARY.
VERY LIGHT RAIN/DRIZZLE WILL LIKELY PERSIST INTO THE OVERNIGHT.
SOUTH WINDS OF 5 TO 10 KTS WILL REMAIN IN PLACE UNTIL THE FRONTAL
PASSAGE BETWEEN 00Z AND 06Z SATURDAY...WITH WINDS THEN TURNING
MORE TO THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS GAYLORD MI
121 PM EST FRI JAN 15 2016
.UPDATE...
ISSUED AT 949 AM EST FRI JAN 15 2016
AREAS FROM GAYLORD NORTH AND HIGHER TERRAIN WILL CONTINUE TO SEE
FZDZ THROUGH MIDDAY. 12Z KAPX SOUNDING SHOWED CLASSIC FREEZING
DRIZZLE PROFILE WITH MID LEVEL DRYING/SATURATED LAYER ABOVE -5C
AND BELOW 0C. SFC LOW NORTH OF MKX WILL MOVE EAST TODAY ACROSS THE
REGION PULLING A COLD FRONT THROUGH LATER TODAY. AS THE LOW PUSHES
THROUGH THE REGION EXPECT SATURATED LAYER TO INCREASE LEADING TO
MORE RAIN/SNOW INSTEAD OF FREEZING DRIZZLE. TEMPERATURES SHOULD
GET TO ABOVE/AROUND 32F TODAY ACROSS NORTHERN LOWER WITH MAINLY
20S ACROSS EASTERN UPPER WITH A COUPLE INCHES OF SNOW POSSIBLE
NORTH BY EVENING.
&&
.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 306 AM EST FRI JAN 15 2016
SURFACE LOW CENTER HAS REACHED SRN WISCONSIN EARLY THIS MORNING...
WITH THE ASSOCIATED WARM FRONT EXTENDING EASTWARD FROM THE LOW
CENTER THRU SRN LWR MICHIGAN. MODELS CONTINUE TO OVER-FORECAST
PRECIP ALONG AND NORTH OF THIS WARM FRONT. LATEST LOOK AT KAPX SHOWS
ONLY PATCHY LIGHT FREEZING DRIZZLE AND/OR FLURRIES LINGERING ACROSS
MANLY THE NRN HALF OF OUR CWA IN THE WAKE OF AN AREA OF LIGHT SNOW
THAT HAS PUSHED NORTH OF OUR CWA. A VERY LIGHT MIST/FREEZING DRIZZLE
IS FALLING HERE AT THE GAYLORD OFFICE...WHICH MAKES SENSE LOOKING AT
OUR MODEL SOUNDINGS FOR EARLY THIS MORNING. LOW LEVELS ARE SATURATED
THRU ABOUT 850 MB...WITH A THICK LAYER OF DRY AIR AT MID LEVELS...
AND THEN ADDITIONAL MOISTURE ABOVE 600 MB. LOW LEVEL MOISTURE COMES
NOWHERE NEAR THE -10 C ISOTHERM AND SURFACE TEMPS REMAIN WELL BELOW
FREEZING AT THIS HOUR...THUS THE PATCHY LIGHT FREEZING DRIZZLE.
BOTH THE LATEST RAP13 AND THE HRRR SHOW ONLY SMALL CHANCES OF LIGHT
PRECIP EARLY THIS MORNING ACROSS MOST OF OUR CWA THRU DAYBREAK...
WITH SOME INDICATION OF GRADUALLY INCREASING POPS AS WE HEAD THRU
THE DAY IN RESPONSE TO INCREASING LIFT AND MOISTURE NEAR THE SURFACE
LOW CENTER. HIGHEST POPS ACTUALLY DEVELOP ACROSS THE SE HALF OF OUR
CWA THIS AFTERNOON JUST AHEAD OF THE SURFACE LOW CENTER AS IT TRACKS
NE THRU NRN LWR MICHIGAN. MODEL SOUNDINGS STILL SUGGEST A RATHER
TIGHT LOW LEVEL THERMAL GRADIENT WILL SET UP ACROSS OUR SRN CWA
TODAY AS THE LOW TRACKS RIGHT OVERHEAD. BASED ON MODEL SOUNDINGS...
PRECIP SHOULD REMAIN ALL SNOW ACROSS ERN UPR MICHIGAN AND THE TIP OF
THE MITT...WITH A MIX OF RAIN/SNOW AND POSSIBLY SOME FREEZING RAIN
AND SLEET MIXING IN AT TIMES ALONG THE TIGHT TEMP GRADIENT. PRECIP
WILL LIKELY BECOME ALL RAIN FOR PORTIONS OF OUR SRN CWA AND
ESPECIALLY OUR SE CWA FROM ROGERS CITY TO HOUGHTON LAKE EASTWARD AS
THE WARMEST AIR SURGES NORTHWARD IN THE AFTERNOON WITHIN THIS AREA
JUST AHEAD OF THE SURFACE LOW CENTER. WITH HIGH TEMPS WARMING INTO
THE MID TO UPPER 30S ACROSS MOST OF NRN LWR MICHIGAN...DO NOT EXPECT
ANY SIGNIFICANT ICE ACCUMULATION...BUT WILL CERTAINLY KEEP A CLOSE
EYE ON PRECIP TYPE AND DURATION AS THIS EVENT UNFOLDS. PRIMARY
CHANGES TO THE FORECAST WILL BE TO DECREASE POPS...ESPECIALLY THIS
MORNING BASED ON NEAR TERM OBSERVED AND MODEL TRENDS. CAA KICKS IN
IN THE WAKE OF THE DEPARTING LOW TONIGHT...SWITCHING PRECIP TYPE
BACK OVER TO ALL SNOW. ALSO...OVER-LAKE INSTABILITY WILL AGAIN
INCREASE WITH ONGOING CAA...TARGETING NW FLOW AREAS FOR HIGHEST POPS
TONIGHT. NEW SNOW ACCUMULATIONS WILL BE A GENERAL 1 TO 3 INCHES
TODAY FOR OUR NRN CWA...WITH ANOTHER INCH OR SO TONIGHT.
&&
.SHORT TERM...(SATURDAY THROUGH SUNDAY NIGHT)
ISSUED AT 306 AM EST FRI JAN 15 2016
SATURDAY AND SUNDAY...COLD AND SNOWY WEATHER TO CONTINUE ACROSS THE
GREAT LAKES REGION THIS WEEKEND. A STORM SYSTEM OVER THE EASTERN
LAKES SATURDAY WILL EXIT NORTHEAST INTO QUEBEC SUNDAY...WHILE AN
UPPER LVL SYSTEM SETTLES INTO THE REGION. MODEL SOUNDINGS AND MSTR
PROGS SHOW MID LVL DRYING (700/500MB RH UNDER 50 PCT) SATURDAY
AFTERNOON AS THE SFC LOW LIFTS NORTHEAST INTO QUEBEC...DIMINISHING
SNOWFALL ACROSS NORTHEAST LOWER SATURDAY AFTERNOON AND EVENING.
HOWEVER LAKE EFFECT PARAMETERS WILL STRENGTHEN SATURDAY AFTERNOON
ACRS THE WRN LAKES...WITH 850MB TEMPS FALLING TO -16C WHILE LOW LVL
INVERSION HEIGHTS INCREASE TO 4K FEET. SFC-850MB WINDS WILL
TRANSITION FROM NORTHWEST TO WEST THROUGH SATURDAY AFTERNOON IN
DIMINISHING CYCLONIC FLOW ON THE BACKSIDE OF THE EXITING STORM
SYSTEM. OVERALL WILL DIMINISH POPS ACROSS NORTHEAST LOWER SATURDAY
MORNING AS DRY MID LVL AIR SETTLES OVER THE REGION...WITH AT LEAST
LIKELY POPS OVER THE WRN LAKES THROUGH SATURDAY EVENING DUE TO LAKE
EFFECTS
SIGNIFICANT SNOW IS POSSIBLE SUNDAY FOR PORTIONS OF NRN MI...THE
COMBINATION OF AN UPPER LOW DROPPING INTO THE GREAT LAKES AS MID LVL
MSTR INCREASES AND LAKE EFFECT PARAMETERS STRENGTHEN. 700/500MB RH
INCREASES TO GREATER THAN 90 PCT SUNDAY WHILE 850/500MB QVECTOR
CONVERGENCE SHOWS STRONG FORCING OVER NRN MI IN ADVANCE OF
APPROACHING UPPER LOW. MODEL SOUNDINGS CONTINUE TO SHOW LAKE
PARAMETERS IMPROVING THROUGH THE DAY SUNDAY AS 850MB TEMPS DROP TO
-24C...INVERSION HEIGHTS INCREASE TO NEARLY 9KT WITH ABUNDANCE MSTR
THROUGH THE COLUMN. LAKES BANDS WILL BE HIGHLY UNORGANIZED THROUGH
18Z SUNDAY AS SFC-850MB WINDS SHIFT FROM SOUTHWEST TO WEST BEFORE
FINALLY LOCKING IN NORTHWEST SUNDAY EVENING INTO MONDAY. OVERALL
WILL MENTION SNOW FOR THE ENTIRE CWA SUNDAY WITH LAKE ENHANCEMENTS
FORCING HIGHEST POPS OVER THE WRN LAKES.
HIGH TEMPERATURES THIS WEEKEND WILL FALL FROM NEAR SEASONAL READINGS
IN THE 20S SATURDAY TO BETWEEN 10 AND 15 DEGREES SUNDAY AS 850MB
TEMPS PLUNGE TO -24C IN DEEPENING UPPER TROUGH.
&&
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 306 AM EST FRI JAN 15 2016
MONDAY THROUGH THURSDAY...SURFACE AND UPPER LVL STORM SYSTEMS WILL
BE IN PLACE OVER THE GREAT LAKES TO BEGIN THE UPCOMING WORK
WEEK...BEFORE SLOWLY EXITING EAST OF THE REGION TUESDAY. THIS
PATTERN WILL GENERATE SNOW ACROSS MUCH OF NORTHERN MICHIGAN MONDAY
WITH LAKE EFFECT SNOW OVER THE WRN LAKES TUESDAY...DUE TO LINGERING
CYCLONIC FLOW ON THE BACK SIDE OF THE EXITING STORM SYSTEM (NW WINDS
SFC-850MB WITH INVERSION HEIGHTS TO 6K FT). TEMPERATURES WILL BE
BELOW NORMAL THROUGH TUESDAY AS 850MB TEMPS IN THE BASE OF THE 500MB
TROUGH DROP TO -24C...FORCING DAYTIME HIGHS TO REMAIN IN THE TEENS
WITH LOWS IN THE SINGLE DIGITS.
WEDNESDAY AND THURSDAY ARE CURRENTLY TRENDING LESS ACTIVE WHEN
COMPARED TO THE PAST WEEK. A LARGE AREA OF HIGH PRESSURE AND DRY AIR
WILL SETTLE OVER THE ENTIRE GREAT LAKES AND OHIO VALLEY BY MID
WEEK...WHILE 500MB HEIGHTS INCREASE ACROSS THE UPPER MIDWEST. ANY
LAKE INFLUENCES WEDNESDAY AND THURSDAY WILL BE HINDERED BY LACK OF
OVER WATER INSTABILITY WITH 850MB TEMPS WARMING TO -8C THURSDAY. THE
WARMING IN MID LVLS WILL HELP DAYTIME TEMPS TREND CLOSER TO MID
JANUARY SEASONAL LEVELS IN THE LOWER 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 114 PM EST FRI JAN 15 2016
WARM FRONT HAS PASSED THRU KMDL/KTVC BRIEFLY IMPROVING
CONDITIONS. KAPN/KPLN WILL REMAIN IN IFR CONDITIONS FOR SEVERAL
MORE HOURS. AREA OF RAINFALL MOVING NORTHEAST WILL CLIP APN BTWN
18Z AND 22Z.
SFC LOW AND COLD FRONT WILL MOVE THROUGH REGION FROM AROUND 21Z
TVC/MBL TO APPROX 02Z AT APN. SNOW SHOWERS WILL KICK IN AFTER COLD
FRONT PASSAGE AND LAKE EFFECT STARTS UP AT TVC/MBL TOWARD MORNING.
&&
.MARINE...
ISSUED AT 306 AM EST FRI JAN 15 2016
WINDS AND WAVES WILL REMAIN JUST AT SCA CRITERIA THRU MUCH OF TODAY
FOR OUR NRN NEARSHORE AREAS JUST NORTH OF THE SURFACE LOW CENTER
TRACK. MAINLY SNOW IS EXPECTED WITHIN THESE AREAS...WITH A WINTRY
MIX OF PRECIP EXPECTED FOR OUR NEARSHORE AREAS SOUTH OF THE ADVISORY
AREAS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...FARINA
NEAR TERM...MLR
SHORT TERM...SWR
LONG TERM...SWR
AVIATION...FARINA
MARINE...MLR
AREA FORECAST DISCUSSION
NWS DULUTH MN
355 PM CST FRI JAN 15 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 354 PM CST FRI JAN 15 2016
MAIN CONCERN FOR THE NEXT 24 HOURS IS LAKE EFFECT SNOW OVER THE
SOUTH SHORE LAKE EFFECT AREAS OF NORTHWEST WISCONSIN...AND THE
ARCTIC AIRMASS THAT WILL BE BRINGING IN VERY COLD TEMPERATURES FOR
THE WEEKEND.
STRONG COLD AIR ADVECTION ACROSS MUCH OF MINNESOTA AND WISCONSIN
TONIGHT WILL BRING IN A VERY COLD AIRMASS FOR SATURDAY...WITH 850MB
TEMPERATURES DOWN AROUND 25 BELOW SATURDAY AT 18Z OVER THE NORTHERN
FORECAST AREA. THIS IS GOING TO CAUSE SURFACE TEMPERAURES TO TAKE A
NOSE DIVE AS WELL...WITH LOW TEMPERATURES TONIGHT FALLING TO BETWEEN
ZERO AND 10 BELOW OVER NORTHWEST WISCONSIN TO 8 TO 18 BELOW OVER
NORTHEAST MINNESOTA. CLOUD COVER IS GOING TO HAVE A FAIRLY LARGE
EFFECT ON THIS...AS THE CLOUD COVER OVER THE AREA IS GOING TO BE
SHUNTED SOUTH WITH THE BAROCLINIC ZONE...AND AN AREA OF CLEAR SKIES
WILL MOVE IN THIS EVENING. HOWEVER...THIS IS NOT A VERY LARGE AREA
OF CLEARING AND MODELS KEEP LOW LEVEL RH VALUES FAIRLY HIGH AND AM
CONCERNED THAT WE WILL HAVE MORE CLOUD COVER. HOWEVER...ALL IT TAKES
IS A SHORT PERIOD OF CLEAR SKIES FOR TEMPERATURES TO REALLY DROP
OFF...EVEN IF THEY RISE AGAIN AFTER THE CLOUDS MOVE IN. NORTHWEST
WINDS OF 5 TO 15 MPH ARE EXPECTED TO PRODUCE WIND CHILL VALUES OF 20
TO 35 BELOW FOR ENOUGH OF THE NIGHT THAT THE WIND CHILL ADVISORY
STILL LOOKS APPROPRIATE FOR TONIGHT AND SATURDAY MORNING.
THE COLD AIR MOVING INTO THE AREA IS GOING TO PRODUCE ANOTHER ROUND
OF LAKE EFFECT SNOW TONIGHT AND SATURDAY FOR THE SOUTH SHORE OF LAKE
SUPERIOR. IN FACT...IT IS ALREADY AFFECTING PORTIONS OF DOUGLAS AND
BAYFIELD COUNTY. SO FAR THE SNOWFALL RATES APPEAR PRETTY LIGHT...BUT
EXPECT THE SNOWFALL TO INTENSIFY AS THE COLDER AIR MOVES IN ALOFT.
850MB TEMPS GO FROM AROUND -12 THIS AFTERNOON TO -18Z BY 12Z...WITH
THE BEST LAYER MOISTURE BETWEEN 06Z AND 12Z. SNOWFALL AMOUNTS OF 3
TO 5 INCHES CAN BE EXPECTED OVER THE NEXT 24 HOURS. THIS IS VERY
CLOSE TO AN ADVISORY...AND WOULD NOT BE SURPRISED IF THE SNOWFALL
RATES LOOK BETTER UPON THE ONSET OF THE SNOW THAT WE MAY NEED TO
ISSUE AN ADVISORY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 354 PM CST FRI JAN 15 2016
A POLAR LOW WILL DROP OUT OF CANADA TO WESTERN LAKE SUPERIOR
SATURDAY NIGHT...AND SURFACE HIGH PRESSURE WILL BE EAST OF THE ROCKY
MOUNTAINS. THE NW FLOW WILL BRING A VERY COLD AIR MASS TO THE
NORTHLAND...THE COLDEST THE NORTHLAND HAS YET SEEN THIS WINTER. THE
850 HPA TEMPERATURES WILL DROP TO ABOUT -26 TO
-30 DEGREES CELSIUS EARLY SUNDAY. CLOUD COVER AND 5 TO 15 MPH WNW
WIND SPEEDS WILL LIKELY BOLSTER OVERNIGHT TEMPERATURES...SO SLIGHTLY
LEANED ON THE WARMER MODEL GUIDANCE FOR THE LOW TEMPERATURE FOR MY
BLEND...SUCH AS THE NAM AND CANADIAN. THE LOWS SHOULD PRIMARILY BE
IN THE TEENS BELOW ZERO...BUT SOME AREAS IN THE WEST COULD FLIRT
WITH 20 DEGREES BELOW ZERO. WIDESPREAD WIND CHILLS OF 30 TO 40 BELOW
ZERO ARE LIKELY.
THE POLAR LOW WILL SHIFT EAST INTO EASTERN CANADA SUNDAY INTO
MONDAY...AND THE SURFACE HIGH PRESSURE WILL MOVE EAST INTO THE
PLAINS. THE CLOUD COVER WILL LIKELY LINGER SUNDAY MORNING...BUT
THERE COULD BE SOME CLEARING LATE SUNDAY INTO MONDAY. THE HIGH
TEMPERATURES ON SUNDAY WILL BE THE COLDEST YET THIS SEASON. HIGHS
WILL BE AROUND -5 DEGREES...BUT NOT QUITE DAILY RECORD TERRITORY.
THE LIGHTER WINDS AND CLEARER SKIES SUNDAY NIGHT...AND THE FACT THAT
SUNDAY AFTERNOON WILL BE SO COLD...SHOULD BE A RECIPE FOR EVEN
COLDER LOW TEMPERATURES FOR SUNDAY NIGHT. LEANED ON THE COLDER MODEL
GUIDANCE...INCLUDING THE CANADIAN. LIKED HOW THE CANADIAN HAD ITS
COLDEST TEMPERATURES ACROSS THE WEST...WHERE IT WILL MORE LIKELY BE
CLEAR WITH THE LIGHTEST WIND SPEEDS. MUCH OF THE REGION WILL SEE
LOWS APPROACH OR REACH -20 DEGREES. MONDAY SHOULD BE WARMER THAN
SUNDAY...PARTLY DUE TO MORE SUNSHINE...SO LEANED ON THE WARMER MODEL
GUIDANCE WITH HIGHS AROUND 0 DEGREES. SUNDAY NIGHT AND MONDAY
MORNING WIND CHILLS WILL LIKELY BE 25 TO 35 BELOW ZERO.
THE COLD NW TO WNW FLOW OVER WESTERN LAKE SUPERIOR WILL RESULT IN A
PROLONGED PERIOD OF LIGHT LAKE EFFECT SNOW FOR DOWNWIND AREAS OF NW
WISCONSIN SATURDAY NIGHT THROUGH MONDAY. MOST OF THE SNOW WILL FALL
SATURDAY NIGHT AND SUNDAY WHEN THE FLOW IS COLDER AND MORE NW...BUT
THE FLOW WILL GET WARMER AND MORE WNW SUNDAY NIGHT AND MONDAY. PARTS
OF NORTHERN IRON COUNTY AND NORTHERN BAYFIELD PENINSULA COULD GET
SEVERAL INCHES SATURDAY NIGHT THROUGH SUNDAY.
THERE WILL LIKELY BE A WARMING TREND THROUGH THE REST OF THE WEEK AS
THE ARCTIC FLOW COMES TO AN END AND THEN PACIFIC AIR...MODIFIED BY
THE ROCKY MOUNTAINS...PUSHES INTO THE UPPER MIDWEST LATER IN THE
WEEK. HIGH TEMPERATURES COULD REACH THE UPPER TEENS AND LOW 20S BY
THURSDAY. TUESDAY LOOKS FAIRLY SUNNY DUE TO THE HIGH PRESSURE BEING
OVER THE NORTHLAND. SOME WEAK DISTURBANCES COULD BRING SOME CLOUD
COVER AND VERY LIGHT SNOW WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1123 AM CST FRI JAN 15 2016
AN AREA OF LOW PRESSURE NEAR CENTRAL LAKE MICHIGAN WILL SHIFT EAST
TOWARDS LAKE HURON TODAY...WHILE ARCTIC HIGH PRESSURE IN CANADA
WILL CONTINUE TO SHIFT SOUTH INTO THE NORTHERN PLAINS AND UPPER
MIDWEST...AND BRING THE NEXT WAVE OF FRIGID AIR.
THERE WILL BE LINGERING IFR/MVFR CONDITIONS ACROSS NE MINNESOTA
AND NW WISCONSIN TODAY...BUT MOST TERMINALS SHOULD SEE A GRADUAL
CLEARING TREND THIS AFTERNOON INTO THIS EVENING. THE EXCEPTION
WILL BE KHYR...WHERE THE MORE HUMID NORTHERLY FLOW FROM LAKE
SUPERIOR WILL MAINTAIN IFR/MVFR CEILINGS THROUGH AT LEAST THE WEE
HOURS OF SATURDAY MORNING. THE WINDS WILL BACK WITH
TIME...BECOMING MORE WNW BY LATER TONIGHT...SO THE LOW CEILINGS AT
KHYR COULD SHIFT TO JUST EAST OF KHYR BEFORE DAWN.
LESS CONFIDENT ABOUT CLOUD COVER LATER TONIGHT AND EARLY SATURDAY.
THE GFS AND HRRR ARE SUGGESTING LOW CLOUD COVER COULD REDEVELOP OR
LINGER INTO THE NIGHT...WHILE THE NAM HAS A CLEARER TREND. LEANED
ON THE NAM SINCE IT SEEMS TO BE FOLLOWING CURRENT TRENDS BETTER.
THERE COULD BE PERIODS OF VERY LIGHT FREEZING DRIZZLE MIXED IN
WITH THE VERY LIGHT SNOW AT KDLH THROUGH THIS AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH -10 -3 -17 -6 / 0 0 0 0
INL -16 -7 -19 -6 / 0 0 0 0
BRD -12 -4 -17 -4 / 0 0 10 10
HYR -6 -1 -17 -5 / 20 0 0 10
ASX 1 3 -8 -1 / 60 40 70 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SATURDAY
FOR MNZ010-011-018-019-025-026-033>037.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ121-
140>148.
&&
$$
SHORT TERM...LE
LONG TERM...GROCHOCINSKI
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1123 AM CST FRI JAN 15 2016
.UPDATE...
ISSUED AT 1123 AM CST FRI JAN 15 2016
UPDATE FOR THE NEW 18Z AVIATION DISCUSSION BELOW.
UPDATE ISSUED AT 1004 AM CST FRI JAN 15 2016
HAVE UPDATED THE FORECAST FOR THE FREEZING DRIZZLE/SNOW SHOWERS
THAT HAVE BLOOMED ACROSS THE ARROWHEAD THIS MORNING. WILL HAVE TO
WATCH THESE CAREFULLY AS MODELS ARE NOT HANDLING AT ALL. THE
DRIZZLE/FLURRIES SEEMS TO BE ASSOCIATED WITH A THICKER BAND OF
CLOUDS APPARENT ON VISIBLE SATELLITE...AND FROM WHAT SATELLITE
SHOWS DO NOT EXPECT IT TO EXPAND ANY FARTHER WEST...BUT IT MAY
EXPAND INTO NW WI FOR THE AFTERNOON.
UPDATE ISSUED AT 551 AM CST FRI JAN 15 2016
UPDATED FOR 12Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CST FRI JAN 15 2016
A CLOSED UPPER LOW WAS LOCATED OVER NORTHERN MANITOBA AT 0815Z. AN
ASSOCIATED LONG WAVE TROF WAS WAS MOVING THROUGH MN. AT THE
SFC...THE LOW CENTER WAS LOCATED IN SW WI WITH AN INVERTED TROF
EXTENDING NWD THROUGH NW WI TO THE MN ARROWHEAD. THE INTERACTION
BETWEEN THESE FEATURES WAS CONTINUING TO PRODUCE LIGHT SNOW FROM THE
ARROWHEAD TO THE TWIN PORTS AND INTO NW WI. HOWEVER...THE SNOW HAS
LESSENED IN INTENSITY AND WILL LET THE WINTER WEATHER ADVISORY GO.
THE SFC LOW WILL MOVE INTO NORTHERN LOWER MI BY 00Z
SATURDAY....WHILE THE UPPER TROF REACHES EASTERN WI. THE BULK OF THE
ACCUMULATING SNOW WILL HAVE ENDED THIS MORNING. HOWEVER...A
TRANSITION TO SOME LAKE INDUCED SNOW SHOWERS IS EXPECTED IN THE
AFTERNOON. NOT EXPECTING A TRUE LAKE EFFECT SNOW EVENT THIS
AFTERNOON AS THE 1000-900MB LAYER REMAINS TOO WARM. WILL SEE SOME
SNOW SHOWERS AND AROUND AN INCH OF ACCUMULATION IN NW WI.
AS THE THE SFC LOW MOVES INTO SOUTHERN ONTARIO TONIGHT...COLD ARCTIC
HIGH PRESSURE BEGINS TO WORK ITS WAY INTO THE REGION. THE COLDER AIR
WILL FILTER ACROSS NW WI AS THE WIND TURNS NW. THIS WILL BEGIN TO
FAVOR A TRUE LAKE EFFECT SNOW. THIS WIND DIRECTION AND TRAJECTORIES
WOULD FAVOR SNOW SHOWERS FROM NE DOUGLAS COUNTY AND ALONG THE
BAYFIELD PENINSULA IN THE EVENING. NOT MUCH IN THE WAY OF LAKE
EFFECT FOR ASHLAND OR IRON COUNTIES AS THE WARM AIR LINGERS AND THIS
IS AN UNFAVORABLE WIND DIRECTION FOR THIS AREA. THE WARM AIR FINALLY
MOVES AWAY LATE TONIGHT AS THE WNW WIND CONTINUES AND COLD AIR
ADVECTION IS FULLY UNDERWAY. THIS AGAIN FAVORS THE AFOREMENTIONED
AREAS. HAVE ALIGNED POPS TO MATCH THIS THINKING.
ELSEWHERE...SOME CLEARING IS EXPECTED TONIGHT OVER THE WESTERN THIRD
OF THE FORECAST AREA WITH THE ARCTIC HIGH BUILDING IN. THE PRESSURE
GRADIENT WILL BEGIN TO TIGHTEN OVER THIS AREA AND WITH THE EXPECTED
MINIMUM TEMPERATURES...HAVE ISSUED A WIND CHILL ADVISORY FROM 06Z
TONIGHT TO 18Z SATURDAY.
ON SATURDAY...THE HIGH COVERS MUCH OF THE FORECAST AREA. THE
EXCEPTION BEING NW WI AND THE ARROWHEAD WHICH WILL STILL BE AFFECTED
BY A TRAILING SFC TROF FROM THE DEPARTING LOW. A WNW WIND WILL
CONTINUE OVER THE REGION ALONG WITH THE COLD AIR ADVECTION. THIS
SCENARIO FAVORS LAKE EFFECT SNOW FROM NE DOUGLAS COUNTY AND THE
BAYFIELD PENINSULA AND HAVE HIGHER POPS IN THIS AREA. LOWER POPS
OVER ASHLAND AND IRON COUNTIES. A VORT MAX WILL ROTATE OVER THE
REGION...BUT WILL LEAVE OUT THE MENTION OF FLURRIES AS THERE IS A
QUESTION OF THE EXTENT OF CLOUD COVER.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CST FRI JAN 15 2016
FRIGID CONDITIONS WILL AMPLIFY INTO THE LATTER HALF OF THE HOLIDAY
WEEKEND. BY 00Z SUNDAY THE CENTER OF THE 500MB COLD CORE WILL
ARRIVE... SWINGING SOUTHWARD THROUGH NORTHERN MINNESOTA AND REACHING
NW WISCONSIN BY 12Z AS SFC HIGH PRESSURE BUILDS ACROSS THE DAKOTAS.
THE STRENGTH OF THE COLD CORE REMAINS ON TRACK WITH PREVIOUS MODEL
RUNS OF 850MB SAMPLES RUNNING AROUND -25C TO -30C. THEREFORE NOT
MUCH WAS NEEDED TO TWEAK THE ONGOING FORECAST. SUNDAY AND MONDAY
MORNINGS WILL BOTH SEE MIN TEMPS RANGING FROM -10F TO -25F... WITH
SLIGHTLY WARMER CONDITIONS NEAR THE LAKE. WINDS AROUND 5 MPH WILL
PRODUCE WIND CHILL TEMPS AS COLD AS -40F AT TIMES.
WIND CHILL HEADLINES WILL ALMOST CERTAINLY BE NEEDED. THE ONE
POTENTIAL COMPLICATION TO THE FORECAST WOULD BE THE DIFFERENCE IN
CLOUD COVER BETWEEN THE ECMWF/GFS AND THE NAM... WITH THE NAM
YIELDING FAR LESS CLOUD COVER... AND A MUCH QUICKER CLEARING SUNDAY
NIGHT/MONDAY MORNING THAN THE OTHER TWO MODELS. SFC HIGH PRESSURE
WILL BE BUILDING ACROSS THE NORTHERN PLAINS BUT WITH CYCLONIC FLOW
IN PLACE... DECIDED TO STAY ON THE PESSIMISTIC SIDE AND TREND
TOWARDS A CLOUDIER SOLUTION. HOWEVER IF SKIES ARE ABLE TO CLEAR OUT
MORE IN TUNE WITH THE NAM... RADIATIONAL COOLING COULD MAKE FOR AN
EVEN COLDER MONDAY MORNING. HIGH TEMPS THROUGH THE WEEKEND WILL
STRUGGLE TO RISE ABOVE ZERO FOR MOST OF THE CWA.
PROLONGED NORTHWESTERLY FLOW ACROSS THE OPEN WATERS OF LAKE SUPERIOR
ALONG WITH COLD TEMPERATURES ALOFT WILL SUPPORT LAKE EFFECT SNOW
ACROSS NW WISCONSIN THROUGH THE EARLY PART OF NEXT WEEK... WITH
CHANCES HIGHEST FOR NORTHERN BAYFIELD... ASHLAND... IRON AND PRICE
COUNTIES. MAY SEE SNOWFALL AMOUNTS AS HIGH AS 3-6 INCHES SATURDAY
THROUGH MONDAY WITH HIGHER AMOUNTS POSSIBLE IN AREAS WHERE LOW-LEVEL
CONVERGENCE IS MOST FOCUSED. FLOW SHIFT WESTWARD BY TUES/WEDS MAKING
LES LESS LIKELY FOR THE COUNTIES IN OUR CWA. ASIDE FROM LES... THE
WEEK LOOKS RATHER DRY FOR MUCH OF THE NORTHLAND.
TEMPERATURE IMPROVEMENT BEGINS TUESDAY AS THE JET STREAM SHIFTS THE
500MB LOW EASTWARD. THE GFS INDICATES NW FLOW TO REMAIN IN PLACE
UNTIL THE FLOW BECOMES QUASI-ZONAL ACROSS THE NORTHLAND BY
THURS/FRI. BY THE END OF THE WEEK TEMPS WILL LIKELY BE CLOSER TO IF
NOT ABOVE CLIMATOLOGICAL NORMALS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1123 AM CST FRI JAN 15 2016
AN AREA OF LOW PRESSURE NEAR CENTRAL LAKE MICHIGAN WILL SHIFT EAST
TOWARDS LAKE HURON TODAY...WHILE ARCTIC HIGH PRESSURE IN CANADA
WILL CONTINUE TO SHIFT SOUTH INTO THE NORTHERN PLAINS AND UPPER
MIDWEST...AND BRING THE NEXT WAVE OF FRIGID AIR.
THERE WILL BE LINGERING IFR/MVFR CONDITIONS ACROSS NE MINNESOTA
AND NW WISCONSIN TODAY...BUT MOST TERMINALS SHOULD SEE A GRADUAL
CLEARING TREND THIS AFTERNOON INTO THIS EVENING. THE EXCEPTION
WILL BE KHYR...WHERE THE MORE HUMID NORTHERLY FLOW FROM LAKE
SUPERIOR WILL MAINTAIN IFR/MVFR CEILINGS THROUGH AT LEAST THE WEE
HOURS OF SATURDAY MORNING. THE WINDS WILL BACK WITH
TIME...BECOMING MORE WNW BY LATER TONIGHT...SO THE LOW CEILINGS AT
KHYR COULD SHIFT TO JUST EAST OF KHYR BEFORE DAWN.
LESS CONFIDENT ABOUT CLOUD COVER LATER TONIGHT AND EARLY SATURDAY.
THE GFS AND HRRR ARE SUGGESTING LOW CLOUD COVER COULD REDEVELOP OR
LINGER INTO THE NIGHT...WHILE THE NAM HAS A CLEARER TREND. LEANED
ON THE NAM SINCE IT SEEMS TO BE FOLLOWING CURRENT TRENDS BETTER.
THERE COULD BE PERIODS OF VERY LIGHT FREEZING DRIZZLE MIXED IN
WITH THE VERY LIGHT SNOW AT KDLH THROUGH THIS AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 17 -10 -3 -17 / 20 0 0 0
INL 7 -17 -7 -22 / 0 0 0 10
BRD 12 -12 -4 -21 / 0 0 0 0
HYR 26 -6 -1 -17 / 40 10 0 10
ASX 26 1 3 -10 / 70 40 20 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST SATURDAY
FOR MNZ010-011-018-019-025-026-033>037.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ121-
140>148.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...GSF
LONG TERM...MCLOVIN
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1217 PM MST FRI JAN 15 2016
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
WITH THE CONTINUATION OF SNOW SHOWERS MOVING IN ON NW FLOW INTO
THE CWA, INCREASED POPS ACROSS THE CENTRAL ZONES FOR THIS
AFTERNOON. REST OF FORECAST WAS LEFT UNTOUCHED. TFJ
914 AM UPDATE...
MAIN UPDATE WAS TO RAISE TEMPERATURES FOR TODAY AS THEY WERE
ALREADY REACHED OR EXCEEDED IN SOME PLACES. OTHERWISE, REST OF
FORECAST LOOKED TO BE ON TARGET SO FAR. TFJ
PREVIOUS DISCUSSION...
FORECAST CHALLENGES IN THE SHORT TERM PERIOD WILL FOCUS ON
TEMPERATURES AND THE EXTENT OF THE SCATTERED SNOW
SHOWERS...ESPECIALLY FOR THE SW HALF OF OUR CWA TODAY...THEN COLD
WIND CHILLS LATER THROUGH THE WEEKEND.
CURRENT WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWS A
GENERAL NW FLOW ALOFT WITH LIMITED MOISTURE RESULTING IN SOME
SCATTERED SNOW SHOWERS PRIMARILY OVER OUR WESTERN ZONES. IT SEEMS
THAT THE MORE AGGRESSIVE MODEL DEPICTIONS OF PRECIP...SUCH AS THE
NAM AND GFS...HAVE PROVEN TOO AGGRESSIVE OVERNIGHT. LIGHTER
AMOUNTS FROM THE HRRR MODEL ARE MORE REPRESENTATIVE OF ACTUAL AREA
REFLECTIVITIES. WOULD EXPECT NEW SNOWFALL TOTALS TO BE CLOSER TO
AROUND 1 INCH THAN 2 INCHES.
WITH THE ARRIVAL OF THE ARCTIC AIR MASS ON SATURDAY...SCATTERED
SNOW SHOWERS AND FLURRIES WILL BE CLEARED OUT AND REPLACED BY A
MORE CERTAIN WEATHER PATTERN OF CLEARING SKIES AND MUCH COLDER
TEMPERATURES OVER OUR CENTRAL AND NE ZONES AND A BAND
ACCUMULATING SNOW OVER OUR SW ZONES.
SATURDAY NIGHT...WIND CHILL CONCERNS WILL ARISE WITH THE COLDEST
TEMPERATURES AND WINDS AROUND 10 MPH POSSIBLE ESPECIALLY FOR OUR
NE CWA ZONES EXPECTED TO BRING WIND CHILL VALUES BETWEEN 25 AND 40
DEGREES BELOW ZERO. NOT YET CONFIDENT OR CLOSE ENOUGH TO GO WITH
ANY WIND CHILL HEADLINE PRODUCTS BUT NEXT FEW SHIFTS WILL NEED TO
SERIOUSLY CONSIDER THE NEED IF TEMPERATURE AND WIND MODEL TRENDS
CONTINUE IN THIS WAY. BMICKELSON
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
EXTENDED PERIOD OPENS NEXT WEEK WITH AN ARCTIC LOW OVER THE
NORTHERN GREAT LAKES AND UPPER RIDGE PUSHING THROUGH THE NORTHERN
ROCKIES.. ARCTIC HIGH MOVING OUT OF THE NORTHERN PLAINS WILL HAVE
LEFT BEHIND A COLD AIRMASS ACROSS MOST OF NORTHEAST MONTANA FOR
MONDAY. AS A SHORTWAVE PUSHES THROUGH THE RIDGE AND ACROSS THE
NORTHERN ROCKIES ON MONDAY...MOISTURE WILL SPREAD OVER THE COLD
AIRMASS...BRINGING LIGHT SNOW INTO EASTERN MONTANA.
REMAINDER OF THE WEEK FEATURES MORE UNCERTAINTY WITH A SERIES OF
PACIFIC OR ARCTIC SHORTWAVES DEPENDING ON THE MODEL SOLUTION.
MODELS TRENDING TOWARD WARMING ALOFT BY THE END OF THE WEEK BUT
GIVEN THE PERSISTENCE OF THE COLD AIR MASS OVER THE REGION WILL
KEEP TEMPERATURES BELOW CLIMO FOR MOST OF THE PERIOD. EBERT
&&
.AVIATION...
MVFR TO IFR CIGS WILL PREVAIL THROUGH THE DAY. REDUCED VSBYS IN
SNOW SHOWERS AND PATCHY FREEZING FOG WILL ALSO CONTINUE AT TIMES
THROUGH THE DAY. NORTH WINDS WILL CONTINUE AT AROUND 5 TO 10 KTS
INTO THIS AFTERNOON. MALIAWCO
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
914 AM MST FRI JAN 15 2016
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY...
MAIN UPDATE WAS TO RAISE TEMPERATURES FOR TODAY AS THEY WERE ALREADY
REACHED OR EXCEEDED IN SOME PLACES. OTHERWISE, REST OF FORECAST
LOOKED TO BE ON TARGET SO FAR. TFJ
PREVIOUS DISCUSSION...
FORECAST CHALLENGES IN THE SHORT TERM PERIOD WILL FOCUS ON
TEMPERATURES AND THE EXTENT OF THE SCATTERED SNOW
SHOWERS...ESPECIALLY FOR THE SW HALF OF OUR CWA TODAY...THEN COLD
WIND CHILLS LATER THROUGH THE WEEKEND.
CURRENT WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD SHOWS A
GENERAL NW FLOW ALOFT WITH LIMITED MOISTURE RESULTING IN SOME
SCATTERED SNOW SHOWERS PRIMARILY OVER OUR WESTERN ZONES. IT SEEMS
THAT THE MORE AGGRESSIVE MODEL DEPICTIONS OF PRECIP...SUCH AS THE
NAM AND GFS...HAVE PROVEN TOO AGGRESSIVE OVERNIGHT. LIGHTER
AMOUNTS FROM THE HRRR MODEL ARE MORE REPRESENTATIVE OF ACTUAL AREA
REFLECTIVITIES. WOULD EXPECT NEW SNOWFALL TOTALS TO BE CLOSER TO
AROUND 1 INCH THAN 2 INCHES.
WITH THE ARRIVAL OF THE ARCTIC AIR MASS ON SATURDAY...SCATTERED
SNOW SHOWERS AND FLURRIES WILL BE CLEARED OUT AND REPLACED BY A
MORE CERTAIN WEATHER PATTERN OF CLEARING SKIES AND MUCH COLDER
TEMPERATURES OVER OUR CENTRAL AND NE ZONES AND A BAND
ACCUMULATING SNOW OVER OUR SW ZONES.
SATURDAY NIGHT...WIND CHILL CONCERNS WILL ARISE WITH THE COLDEST
TEMPERATURES AND WINDS AROUND 10 MPH POSSIBLE ESPECIALLY FOR OUR
NE CWA ZONES EXPECTED TO BRING WIND CHILL VALUES BETWEEN 25 AND 40
DEGREES BELOW ZERO. NOT YET CONFIDENT OR CLOSE ENOUGH TO GO WITH
ANY WIND CHILL HEADLINE PRODUCTS BUT NEXT FEW SHIFTS WILL NEED TO
SERIOUSLY CONSIDER THE NEED IF TEMPERATURE AND WIND MODEL TRENDS
CONTINUE IN THIS WAY. BMICKELSON
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
EXTENDED PERIOD OPENS NEXT WEEK WITH AN ARCTIC LOW OVER THE
NORTHERN GREAT LAKES AND UPPER RIDGE PUSHING THROUGH THE NORTHERN
ROCKIES.. ARCTIC HIGH MOVING OUT OF THE NORTHERN PLAINS WILL HAVE
LEFT BEHIND A COLD AIRMASS ACROSS MOST OF NORTHEAST MONTANA FOR
MONDAY. AS A SHORTWAVE PUSHES THROUGH THE RIDGE AND ACROSS THE
NORTHERN ROCKIES ON MONDAY...MOISTURE WILL SPREAD OVER THE COLD
AIRMASS...BRINGING LIGHT SNOW INTO EASTERN MONTANA.
REMAINDER OF THE WEEK FEATURES MORE UNCERTAINTY WITH A SERIES OF
PACIFIC OR ARCTIC SHORTWAVES DEPENDING ON THE MODEL SOLUTION.
MODELS TRENDING TOWARD WARMING ALOFT BY THE END OF THE WEEK BUT
GIVEN THE PERSISTENCE OF THE COLD AIR MASS OVER THE REGION WILL
KEEP TEMPERATURES BELOW CLIMO FOR MOST OF THE PERIOD. EBERT
&&
.AVIATION...
MVFR TO IFR CIGS WILL PREVAIL THROUGH THE DAY. REDUCED VSBYS IN
SNOW SHOWERS AND PATCHY FREEZING FOG WILL ALSO CONTINUE AT TIMES
THROUGH THE DAY. NORTH WINDS WILL CONTINUE AT AROUND 5 TO 10 KTS
INTO THIS AFTERNOON. MALIAWCO
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORMAN OK
334 PM CST FRI JAN 15 2016
.DISCUSSION...
ACCUMULATING SNOW LATE TONIGHT INTO SATURDAY IS THE MAIN CONCERN.
EXPANDED THE WINTER WEATHER ADVISORY A BIT FARTHER EAST TO INCLUDE
THE LAWTON...ANADARKO...AND CHICKASHA AREAS BASED ON LATEST MODEL
GUIDANCE...PARTICULARLY THE RUC13 AND HRRR. CONFIDENCE IS RATHER
HIGH THAT 1 TO 3 INCHES OF WET SNOW WILL OCCUR IN THESE AREAS.
TONIGHT...CLOUDS WILL QUICKLY INCREASE. PRECIPITATION WILL BEGIN
IN FAR WESTERN OKLAHOMA AS EARLY AS 10 PM...BUT MAINLY HOLD OFF
UNTIL AFTER 2 AM. MOST PRECIPITATION SHOULD BEGIN AS LIGHT RAIN
DUE TO WARM BOUNDARY LAYER TEMPERATURES NEAR THE GROUND. AS THE
AIR NEAR THE GROUND COOLS AND SATURATES...PRECIPITATION SHOULD
MAINLY CHANGE FROM LIGHT RAIN TO LIGHT TO MODERATE SNOW. A BRIEF
PERIOD OF SLEET MAY OCCUR DURING THIS TRANSITION...BUT WAS NOT
MENTIONED IN THE GRIDS AS RAIN OR SNOW SHOULD BE THE PRIMARY
PRECIPITATION TYPES.
LATEST MODEL GUIDANCE...PARTICULARLY THE HRRR...HAS BEEN DEPICTING
BANDS OF PRECIPITATION OCCURRING LATE TONIGHT INTO SATURDAY
MORNING...LIKELY AS A RESULT OF 850-700 MB FRONTOGENESIS. THESE
BANDS SEEM TO BE MOST LIKELY IN THE 3 AM TO 11 AM TIME FRAME NEAR
AND JUST SOUTH OF I-40 WEST OF OKLAHOMA CITY. THESE BANDS WILL
HAVE THE GREATEST POTENTIAL TO PRODUCE ACCUMULATING SNOWFALL AS
THE SNOW MAY BE MODERATE TO PERHAPS HEAVY AT TIMES WITH
VISIBILITIES FALLING TO 1/2 MILE OR LESS. MODERATE TO HEAVY SNOW
WOULD BE NECESSARY TO ACCUMULATE ON ROADWAYS DUE TO WARM GROUND
TEMPERATURES FROM HEATING THIS AFTERNOON AND YESTERDAY.
BY SATURDAY MORNING...MOST SNOW BANDS APPEAR TO BE OVER
SOUTHWESTERN OKLAHOMA...SLOWLY WEAKENING AFTER 11 AM. RIGHT
NOW...APPEARS THE HEAVIEST SNOW WILL OCCUR SOUTH OF THE OKLAHOMA
CITY METRO AREA AND NORTH OF WICHITA FALLS. LOCATIONS IN SOUTHERN
OKLAHOMA INCLUDING PAULS VALLEY...DUNCAN...AND ADA...MAY BE IN THE
HEAVIEST BANDS OF SNOW AS WELL...THOUGH NOT CONFIDENT THAT THIS
WILL BE THE CASE.
OVERALL...THINK 1 TO 3 INCHES OF SNOWFALL ACCUMULATION IN
ADVISORY AREA SEEM REASONABLE...THOUGH WOULD NOT BE SURPRISED IF
LOCALLY HEAVIER AMOUNTS WOULD BE POSSIBLE IF A MODERATE TO HEAVY
BAND OF SNOW SET UP OVER A GIVEN AREA FOR SEVERAL HOURS. MOST
ACCUMULATIONS WILL BE ON GRASSY SURFACES DUE TO WARM GROUND
SURFACES. SURFACE TEMPERATURES SHOULD STAY NEAR OR JUST ABOVE
FREEZING...32 DEGREES...IN MOST LOCATIONS THAT RECEIVE
ACCUMULATING SNOWFALL.
SATURDAY AFTERNOON THROUGH SUNDAY MORNING...PRECIPITATION CHANCES
WILL END AND SKIES SHOULD CLEAR. WOULD NOT BE SURPRISED IF LIGHT
FOG OR FREEZING FOG FORMED ACROSS SNOW COVERED AREAS...BUT DID
NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
SUNDAY AFTERNOON AND NIGHT...A STRONG COLD FRONT WILL MOVE
THROUGH THE AREA AND BRING COLDER TEMPERATURES. MOISTURE APPEARS
TO BE LIMITED WITH THE FRONTAL PASSAGE...THOUGH A FEW LIGHT
SPRINKLES OR SNOW FLURRIES COULD RESULT. THERE IS AN OUTSIDE
CHANCE FOR ADDITIONAL BAND OF SNOWFALL SUNDAY NIGHT SOMEWHERE
ACROSS THE AREA...PARTICULARLY NEAR THE RED RIVER. TEMPERATURES
WILL PLUMMET SUNDAY NIGHT INTO THE TEENS AND 20S.
MONDAY THROUGH FRIDAY...A WARMING TREND WILL OCCUR THROUGH
MIDWEEK. ANOTHER STORM SYSTEM MAY BRING ADDITIONAL PRECIPITATION
CHANCES WEDNESDAY THROUGH FRIDAY...THOUGH PRECIPITATION TYPES AND
AMOUNTS REMAIN UNCERTAIN.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 31 43 27 39 / 60 70 0 10
HOBART OK 32 39 28 42 / 60 100 0 10
WICHITA FALLS TX 35 42 29 50 / 20 80 0 10
GAGE OK 25 44 25 31 / 60 20 0 10
PONCA CITY OK 26 43 25 32 / 10 10 0 10
DURANT OK 35 43 29 49 / 10 60 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST
SATURDAY FOR OKZ009-014-016-021>023-027-033>036-038.
TX...NONE.
&&
$$
23/17
AREA FORECAST DISCUSSION
NWS PORTLAND OR
852 AM PST FRI JAN 15 2016
.SYNOPSIS...BRIEF BREAK IN THE WEATHER TODAY...BUT NEXT FRONT ARRIVES
TONIGHT. WILL BE A WET AND BREEZY WEEKEND...WITH SNOW ABOVE THE
PASSES IN THE CASCADES. AFTER A DRY DAY ON MON...UNSETTLED WEATHER
PATTERN CONTINUES NEXT WEEK.
&&
.UPDATE...A FEW SHOWERS LINGER OVER THE INTERIOR LOWLANDS THIS
MORNING AND IS EXPECTED TO CONTINUE TO DIMINISH. THERE ARE MORE
SHOWERS OVER THE SOUTH WA CASCADES AND THE NORTHERN COAST/COAST RANGE
ZONES.LATEST HRRR AND NAM SHOW SCATTERED SHOWERS PERSISTING IN
THESE AREAS SO WILL INCREASE POPS IN THOSE AREAS. HRRR AND GFS TIMING
OF NEXT BOUT OF RAIN IN GOOD AGREEMENT WITH LIGHT RAIN REACHING THE
COAST LATE THIS AFTERNOON AND EVENING FOR THE INTERIOR. NAM HAS
SLOWER TIMING BUT IT MAY BE A BIAS IN THE MODEL HANDLING WARM
ADVECTION PCPN. SAT SYSTEM LOOKS A LITTLE WINDIER FOR THE COAST THAN
CURRENT FORECAST AND WILL ADDRESS THAT IN THE AFTERNOON UPDATE ONCE
WE HAVE FULL MODEL SUITE. /MH
PREVIOUS DISCUSSION FOLLOWS...
.SHORT TERM...TODAY THROUGH MONDAY...
A WEAK UPPER DISTURBANCE OFFSHORE COMBINED WITH ONSHORE FLOW WILL
MAINTAIN A MINOR THREAT OF SHOWERS TODAY...MAINLY THIS AM. APPEARS
WILL SEE GENERALLY DRY CONDITIONS FOR AFTERNOON INTO THIS EVENING.
LIKELY TO BE LAST DECENT RAIN-FREE PERIOD UNTIL EARLY NEXT WEEK.
UPPER RIDGING OFFSHORE WILL PUSH OVER THE PAC NW TODAY...BUT IS BEING
PUSHED INLAND AS STRONG SYSTEM UPSTREAM APPROACHES. MODELS STILL
RATHER GOOD AGREEMENT WITH PRECIPITATION SHIELD REACHING THE COAST BY
LATE THIS AFTERNOON...AND SPREADING INLAND THIS EVENING. THIS SYSTEM
HAS TAPPED SUBTROPICAL MOISTURE...WITH A RESPECTABLE PRECIPITABLE
WATER PLUME. BOTH GFS AND NAM MODELS SHOW PRECIPITABLE WATER VALUES
OF 1.20 TO 1.25 PUSHING OVER THE REGION LATE TONIGHT AND EARLY SAT
AM. THIS WILL SUPPORT RAINFALL TONIGHT/SAT AM OF 1 TO 3 INCHES OVER
THE MTNS...WITH HEAVIEST OVER THE COAST MTNS...AND GENERALLY 0.50 TO
1.00 INCH ELSEWHERE.
WILL BECOME BREEZY ALONG THE COAST AS WILL SEE BIT OF LOW LEVEL
BARRIER JET FORM NEAR THE COAST LATER TONIGHT INTO SAT AM AHEAD OF
THE COLD FRONT. SHOULD BE ENOUGH TO SUPPORT GUSTS OF 45 TO 55 MPH ON
THE COAST. WINDS EASE AS FRONT PUSHES ONSHORE EARLY SAT AFTERNOON.
MODELS HAVE BEEN BIT SUGGESTIVE OF A SURFACE LOW FORMING OFFSHORE
LATER SAT AFTERNOON...AND SWINGING THE LOW INTO W WASHINGTON BY SAT
EVENING. THIS LOW WILL TIGHTEN PRES GRADIENTS OVER REGION... WITH
BREEZY SOUTH WINDS FOR SAT AFTERNOON/EARLY EVENING. LIKELY TO SEE
GUSTS 40 TO 50 MPH ALONG THE COAST AND OVER COAST RANGE...WITH GUSTS
20 TO 30 MPH FURTHER INLAND IN THE AFTERNOON.
SNOW LEVELS ARE AROUND 2500 TO 3000 FEET THIS AM...BUT WILL SLOWLY
RISE TODAY AND THIS EVENING. AS THE WARMER AIR WITH THE FRONT
TONIGHT...SNOW LEVELS WILL RISE MORE QUICKLY TONIGHT...AND SIT
BETWEEN 5500 AND 6500 FT SAT AM. ONCE COLD FRONT MOVES INLAND... SNOW
LEVELS LOWER AGAIN...DOWN TO NEAR 4000 FEET BY SAT EVENING.
SHOWERS WILL DECREASE SAT EVENING...BUT ANOTHER FAST MOVING SYSTEM
WILL ARRIVE LATER SAT NIGHT AND SUN. THIS WILL BE A VERY WET DAY FOR
SUN...WITH RAINFALL BIT MORE THAN THAT OF SAT AM. STRONG SW 125 KT
JET ALOFT WILL HELP PUSH THE COLD FRONT ONSHORE SUN AFTERNOON. WILL
HAVE TO WATCH WEATHER PATTERN AS SOME POTENTIAL FOR AN BOOST OF WINDS
ALONG THE COAST AS LOW LEVEL BARRIER JET TRIES TO FORM. MODELS
SHOWING 1500 FT WINDS OVER COASTAL WATERS OF 55 TO 70 MPH...WHICH
COULD CONTRIBUTE TO GUSTY SOUTH WINDS ON HEADLANDS OF 50 TO 60 MPH.
AGAIN...WILL HAVE LATER SHIFTS LOOK AT THIS POTENTIAL.
LIKE SAT...SNOW LEVELS LIFT UP TO 6000 FT BRIEFLY ON SUN...THEN BACK
TO 4000 OR 4500 FT SUN NIGHT. MODELS HAVE CONTINUED TREND OF SHOWING
REGION BETWEEN SYSTEMS ON MON. SO...HAVE CUT BACK ON POPS AND CLOUDS
FOR MON. OVERALL...MON LOOKS TO BE A DRY DAY...WITH A SHOWER OR TWO
OVER THE CASCADES EARLY. UNFORTUNATELY...CLOUDS INCREASING LATE IN
DAY AS PARADE OF FRONTS CONTINUES. /ROCKEY
.LONG TERM...MONDAY NIGHT THROUGH THURSDAY...
THE STRONG NORTH PACIFIC ZONAL JET CONTINUES THROUGH THE EXTENDED
WITH IT SPLITTING AS IT NEARS THE WEST COAST. LIKE RECENT SYSTEMS
SOME OF THE ENERGY SPINS OVER THE FORECAST AREA WHILE THE MAJORITY OF
THE ENERGY AND MOISTURE HEADS TOWARD CALIFORNIA. ALSO CLIMATE
PREDICTION CENTER 6-10 DAY SHOWS THE MEAN 500 MB RIDGE POSITION OVER
EASTERN OREGON AND IDAHO LEAVING THE FORECAST AREA OPEN TO PACIFIC
SYSTEMS. MODELS CONTINUE TO SHOW UPPER LEVEL RIDGING BUILDING OVER
THE AREA ON WEDNESDAY AND GIVE US A BRIEF PERIOD OF RELIEF FROM THE
RAIN...BUT CONFIDENCE IS LOW SO WILL MAINTAIN AT LEAST CLIMO POPS IN
THE FORECAST. SEASONAL TEMPERATURES EXPECTED THROUGH NEXT WEEK. /MH
&&
.AVIATION...MOSTLY MVFR CONDITIONS WILL RISE TO MOSTLY VFR THIS
AFTERNOON AS RESIDUAL SHOWERS LIFT NORTH OF THE AREA. THE NEXT
STRONG OCCLUDED FRONT WILL BRING MORE RAIN TO THE AREA TONIGHT AND
SATURDAY MORNING...AND LOWERING CONDITIONS TO MVFR.
LIGHT EAST WINDS THROUGH THE COLUMBIA RIVER GORGE TODAY WILL
RESTRENGTHEN AGAIN LATER TONIGHT.
KPDX AND APPROACHES...CONDITIONS LIFTING TO MAINLY VFR THIS
MORNING AND AFTERNOON. MORE RAIN AND LOWERING CIGS EXPECTED AFTER
MIDNIGHT TONIGHT...POSSIBLY LOWERING CONDITIONS TO MVFR LATER
TONIGHT AND SATURDAY MORNING. PT
&&
.MARINE...THE SYSTEM FROM THURSDAY WAS LIFTING NORTH OF OUR AREA
THIS MORNING. WINDS HAVE BACKED TO THE SOUTH AHEAD OF THE NEXT
SYSTEM...AND ARE ABOVE SMALL CRAFT ADVISORY CRITERIA. WINDS WILL
CONTINUE TO RAMP UP AS THE NEXT SYSTEM APPROACHES...REACHING HIGH
END GALES TONIGHT AND SATURDAY MORNING BEFORE THE OCCLUDED FRONT
WITH THAT SYSTEM MOVES ONSHORE. WE MAY GET VERY CLOSE TO STORM
FORCE IN THE OUTER WATERS. WINDS EAST BACK TO SMALL CRAFT
ADVISORY THRESHOLDS SATURDAY AFTERNOON BEHIND THE FRONT. FOR
NOW...THE NAM MODEL LOOKS OVERDONE WITH A SECONDARY LOW OFF THE
COAST LATER SATURDAY AND SATURDAY EVENING. THE NEXT STRONG FRONT
BRINGS MORE HIGHER END GALES TO THE WATERS LATER SATURDAY NIGHT
AND SUNDAY MORNING.
EVEN A BIT HIGHER THAN THE WAVE MODELS SUGGESTED...SEAS HAVE
REACHED 15 OR 16 FT THIS MORNING AT OUR BUOYS AND WILL STAY NEAR
THAT FOR A WHILE TODAY BEFORE EASING BACK DOWN A COUPLE OF FEET
LATER TODAY AND THIS EVENING. SEAS WILL LIKELY GET CLOSE TO 20 FT
LATER TONIGHT AND SATURDAY MORNING...ESPECIALLY IF WE KNOCK ON THE
STORM FORCE DOOR FOR THE WINDS. SEAS DROP DOWN TO 15 TO 17 FT
LATER SATURDAY AND SATURDAY NIGHT BEFORE BUILDING BACK CLOSE TO 20
FT WITH THE NEXT FRONT LATER SATURDAY NIGHT AND EARLY SUNDAY.
ANOTHER AREA HIGHER SEAS SPREADS IN LATER SUNDAY AND SUNDAY
EVENING...WITH SEAS REACHING THE 22 TO 25 FT RANGE. PT
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 PM PST THIS
AFTERNOON FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 1 PM PST SATURDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST
THIS AFTERNOON 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 SATURDAY.
&&
$$
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...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1019 AM CST FRI JAN 15 2016
.UPDATE...
THE COLD FRONT ALREADY ARRIVED IN SOUTHERN WI THIS MORNING. BESIDES
INCREASING NORTHWEST WINDS AND GRADUALLY FALLING TEMPERATURES...
THE COLD FRONT IS MARKED BY LOW CLOUDS AND LIGHT FOG. THESE
CONDITIONS WILL PERSIST THROUGH THE AFTERNOON. CLOUD HEIGHTS WILL
RISE A BIT AND FOG SHOULD DIMINISH LATE THIS AFTERNOON INTO THE
EVENING... ALTHOUGH THERE IS A CHANCE FOR FLURRIES.
THE RAP BUFKIT SHOWS DRY AIR ABOVE 4000 FEET THROUGH THE EVENING
WHILE THE NAM KEEPS PICKING UP ON THE DEFORMATION AREA ON THE BACK
SIDE OF DEPARTING LOW PRESSURE TO PRODUCE A SHORT PERIOD OF DEEPER
SATURATION AND THUS LIGHT SNOW/FLURRIES IN THE 21 TO 02Z TIME PERIOD.
&&
.AVIATION/18Z TAFS/...
THE COLD FRONT IS BRINGING INCREASING NORTHWEST WINDS... FALLING
TEMPERATURES... LOW LOW CLOUDS BELOW 600 FEET AND REDUCED VISIBILITY
OF 3SM OR LESS TO ALL OF SOUTHERN WI LATE THIS MORNING. THE MOISTURE
DOES NOT LOOK SUFFICIENTLY DEEP TO PRODUCE DRIZZLE TODAY OR FLURRIES
UNTIL POSSIBLY LATE AFTERNOON THROUGH THE EVENING.
VSBY AND CIGS SHOULD IMPROVE TO MVFR LATE IN THE AFTERNOON. MVFR
CIGS ARE POSSIBLE THROUGH THE NIGHT... ALTHOUGH THERE ARE SIGNALS
FOR A PERIOD OF VFR OVERNIGHT BEFORE THE NEXT COLD FRONT ARRIVES MID
TO LATE SATURDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 333 AM CST FRI JAN 15 2016/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
AN UPPER LEVEL TROUGH OVER THE UPPER MISSISSIPPI VALLEY WILL
MOVE ACROSS WISCONSIN TODAY AND EXIT THE EAST EARLY THIS EVENING.
WEAK UPPER DIVERGENCE AND 700 MB UPWARD MOTION EXISTS UNTIL THE
TROUGH AXIS MOVES OFF.
THE MID LEVELS DO NOT QUITE SATURATE SO ANY PRECIPITATION WOULD
BE DUE TO THE LOW LEVEL RH INCREASE AND WEAK FORCING. THEREFORE
EXPECT MAINLY TRACE PRECIPITATION WITH THE TROUGH.
MAIN VERY SHORT TERM CONCERN IS THE DENSE FOG NEAR THE WARM FRONT
ACROSS CENTRAL WISCONSIN AND IN THE LIGHT WIND REGIME NEAR THE
SURFACE LOW.
COLD AIR ADVECTION OCCURS LATER THIS MORNING SOUTH CENTRAL AND
ACROSS SOUTHERN WISCONSIN TONIGHT.
SATURDAY AND SATURDAY NIGHT - CONFIDENCE...MEDIUM
COLD ADVECTION WILL BE ON THE INCREASE ESPECIALLY INTO THE
AFTERNOON WITH 925 TEMPS DROPPING THROUGH THE NEGATIVE TEENS
CELSIUS. A MOSTLY SHEARED VORT MAX PASSES THROUGH CENTRAL AND
SOUTHERN WI DURG THE DAY THOUGH PRIMARY VORTEX HOLDS OFF TO THE
NORTHWEST. THIS PLOWS IN SATURDAY NIGHT WITH APPRECIABLE CRASHING
OF 1000/500 MILLIBAR THICKNESS TO UNDER 500 DM. 850/925 TEMPS
DROPOFF AS WELL WITH THE BRUNT OF LOW LEVEL COLD ADVECTION. THE
NAM IS NOT AS COLD AND ALSO BRINGS LIGHT QPF INTO SRN WI WITH MORE
POTENT WAVE RIDING AROUND UPPER LOW.THE GFS AND ECMWF ARE DRY.
WILL BRING SOME SMALL POPS INTO THE SW CWA FOR NOW TO MATCH UP
WITH KARX. MAIN STORY WILL BE THE FRIGID CONDITIONS AND POTENTIAL
FOR A WIND CHILL ADVISORY.
SUNDAY - CONFIDENCE...MEDIUM
BITTERLY COLD DAY WITH DECENT PRESSURE GRADIENT AND CORE OF LOW
LEVEL THERMAL TROUGH AT ITS PEAK WITH 925 TEMPS IN THE NEGATIVE
MID 20S CELSIUS. SINGLE DIGITS SFC TEMPS EXPECTED WITH POTENTIAL
FOR SOME SPOTS TO NOT CLIMB ABV ZERO. STILL SEEING INFLUENCE OF
THE POTENT VORT MAX RIDING ON SW PERIPHERY OF THE UPPER LOW NEAR
LAKE SUPERIOR. THE NAM IS ONLY MODEL TO GENERATE QPF. WILL HOLD
OFF ON ANY SNOW MENTION WITH BUFKIT SOUNDINGS SHOWING OVERRIDING
INFLUENCE OF DRY COLUMN AND SUBSIDING INFLUENCE OF THE LOW LEVEL
COLD ADVECTION.
SUNDAY NIGHT AND MONDAY - CONFIDENCE...MEDIUM
FRIGID AIRMASS PERSISTS AS CORE OF LOWEST THICKNESSES...SUB 500DM
AND BITTERLY COLD LOW LEVEL THERMAL TROUGH REMAIN IN PLACE. SOME
SLACKENING OF THE GRADIENT THOUGH 925 WINDS REMAIN ELEVATED THOUGH
NOT AS STRONG AS SURFACE/850 RIDGE AXIS DRAW CLOSER. STILL ANOTHER
DAY WITH TEMPS LIKELY NOT REACHING DOUBLE DIGITS WITH 925 TEMPS
STILL CLOSE TO -20 CELSIUS. WIND CHILL ADVISORY LIKELY CONTINUING
FOR AT LEAST THE MORNING HOURS.
TUESDAY - CONFIDENCE...MEDIUM
COLD EASES WITH THE 500 MILLIBAR LOW WELL TO THE EAST AND SFC/850
RIDGE AXES STRETCHING FROM OH VLY INTO THE UPR MIDWEST. 925 TEMPS
MODERATE THROUGH THE NEGATIVE TEENS CELSIUS SO EXPECT TEMPS TO
REBOUND BACK TO DOUBLE DIGITS.
TUESDAY NIGHT AND WEDNESDAY - CONFIDENCE...MEDIUM
GFS/ECWMF TAKE POSITIVE TILT SHORTWAVE SOUTH OF THE AREA WITH
BOTH MODELS GRAZING THE AREA WITH SOME LIGHT QPF FROM THIS
FEATURE. SUPERBLEND POPS SHOW SLGT CHCS. THE GEM SHOWS THIS AS A
MORE ELONGATED/SHEARED FEATURE THOUGH SHOWS A BIT MORE ISENTROPIC
FEATURE AND ACTUALLY MORE OF A QPF SIGNAL THAN THE ECMWF. THE
SUPERBLEND POPS SHOW SLGT CHCS AND WILL RETAIN THESE IN THE
GRIDS.
THURSDAY - CONFIDENCE...LOW
MODEL DIFFERENCES WITH HANDLING OF SHORTWAVE ENERGY RIDING ACRS
ERN SIDE OF WRN RIDGE. THE ECMWF SHOWS A MORE AMPLIFIED WAVE WHILE
THE GFS SHOWS A MORE QUICK HITTING VORT. SUPERBLEND POPS ARE
LEANING DRY.
AVIATION/12Z TAFS/...AREAS OF LIFR FOG AHEAD OF AN AREA OF LOW
PRESSURE... CENTERED OVER SOUTHWEST/WEST CENTRAL WISCONSIN THAT
PUSHES EAST.
CONFIDENCE IS LOW ON THE POTENTIAL FOR DRIZZLE TO DEVELOP MORE TO
THE SOUTH THIS MORNING. THIS MOIST LAYER LOOKS TO DEEPEN AFTER
SUNRISE. MVFR AND IFR CIGS EXPECTED ESPECIALLY AFTER THE COLD
FRONTAL PASSAGE.
MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT LATER THIS
AFTERNOON INTO SATURDAY AFTERNOON AS GUSTY NORTHWEST WINDS DEVELOP
BEHIND AN EXITING LOW PRESSURE SYSTEM. HIGH WAVES SHOULD DEVELOP
TOWARD THE OPEN WATERS...AS WELL AS THE POSSIBILITY OF SOME
FREEZING SPRAY AS MUCH COLDER AIR MOVES ACROSS THE GREAT LAKES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 2 PM CST
SATURDAY FOR LMZ643>646.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SATURDAY THROUGH THURSDAY...COLLAR
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
238 PM MST FRI JAN 15 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 239 PM MST FRI JAN 15 2016
MODELS CONTINUE TO STRUGGLE WITH THE PLACEMENT OF SEVERAL BANDS OF
PRECIPITATION IN THE SHORT TERM...IN ADDITION TO THE ARCTIC FRONT
SATURDAY/SATURDAY NIGHT AND HOW FAR WEST IT STALLS. FOR THIS
AFTERNOON...SNOW IS GRADUALLY TAPERING OFF TO SNOW FLURRIES
ACROSS CARBON COUNTY AFTER THE LOCALLY HEAVY SNOW SHOWERS FROM
EARLIER THIS MORNING. EXPECT A BRIEF LULL INTO LATE THIS AFTERNOON
BEFORE A VORTICITY MAX ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE
PUSHES SOUTHEAST ACROSS SOUTHEAST WYOMING THIS EVENING. THERE IS
SOME GOOD LLVL INSTABILITY FOR THIS TIME OF THE YEAR AS WELL AS
SOME FRONTOGENESIS ALONG THE LARAMIE RANGE...AND ALONG AND SOUTH
OF I80. THE TRICKY PART IS...IF THIS BAND OF SNOW DEVELOPS FURTHER
SOUTH INTO COLORADO...THE I80 CORRIDOR MAY RECEIVE NOTHING OUTSIDE
OF A FEW FLURRIES. INCREASED POP BETWEEN 40 TO 80
PERCENT...HIGHEST IN THE MOUNTAINS. WILL NEED TO KEEP AN EYE ON
THE I80 SUMMIT AS WELL AS LARAMIE AND CHEYENNE FOR ACCUMULATING
SNOW AND SOME IMPACTS TO ROADS THIS EVENING. SOME OF THESE SNOW
BANDS MAY BE MODERATE TO HEAVY AT TIMES IN INTENSITY.
SATURDAY...ARCTIC FRONTAL BOUNDARY STILL PROJECTED TO MOVE
SOUTHWARD AND JAM UP EAST OF THE LARAMIE RANGE ON SATURDAY. DECENT
FRONTAL FORCING ALONG AND EAST OF THE LARAMIE RANGE WITH AMPLE
MOISTURE AND INSTABILITY EXPECT TO GET A FAIRLY DECENT COVERAGE OF
SNOW SHOWERS IN BANDS ACROSS SOUTHEAST WYOMING AND EAST INTO THE
NEBRASKA PANHANDLE SATURDAY INTO SATURDAY NIGHT AS ANOTHER
SHORTWAVE MOVES THROUGH. OUT WEST FAVORABLE ACTIVE NORTHWESTERLY
FLOW WITH UPSLOPE WILL KEEP SNOW GOING IN THE MOUNTAINS WELL INTO
THE WEEKEND. AN ADDITIONAL 12 TO 18 INCHES OF SNOW CAN BE EXPECTED
FOR A 3 DAY WEEKEND TOTAL ABOVE 9500 FT IN THE SIERRA MADRE RANGE
WITH 8 TO 12 INCHES ABOVE 9500 FT FOR THE SNOWY RANGE. LOWER 24
HOUR TOTALS IN THE MOUNTAINS WILL KEEP THE EVENT IN THE ADVISORY
CATEGORY. WILL NEED TO MONITOR FOR POSSIBLE ADDITION OF A WINTER
WEATHER ADVISORY FOR THE SNOWY RANGE AS WELL FOR SATURDAY INTO
SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 239 PM MST FRI JAN 15 2016
SNOW SHOWERS TAPER OFF BY SUNDAY AFTERNOON IN THE LOWER ELEVATIONS
WITH SNOW CONTINUING IN THE MOUNTAINS THROUGH WEDNESDAY GIVEN
FAVORABLE AND ACTIVE MIDLEVEL FLOW. AFTER A COUPLE OF SHORTWAVES
MOVE THROUGH MONDAY INTO WEDNESDAY...IT APPEARS WE DRY OUT
SUFFICIENTLY TO NEGATE POPS THURSDAY INTO NEXT WEEKEND AS A
RATHER LARGE AMPLITUDE MID/UPPER RIDGE TRAVERSES THE
CENTRAL/NORTHERN ROCKIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1017 AM MST FRI JAN 15 2016
CONFIDENCE INCREASING THAT SNOW IS GOING TO IMPACT SEVERAL
AIRPORTS IN SOUTHEAST WYOMING AND POSSIBLY THE NORTHERN NEBRASKA
PANHANDLE. HRRR GUIDANCE SHOWING A CLIPPER SYSTEM OVER
NORTHEASTERN WYOMING MOVING SOUTHEAST BRINGING SNOW AND LOWERING
CONDITIONS TO KCDR AND KAIA. MAINLY AFTER 00Z...BUT COULD SEE IT A
LITTLE SOONER. FOR THE I-80 CORRIDOR FROM CHEYENNE TO
RAWLINS...LOOKING AT DETERIORATING CONDITIONS THROUGH THE
AFTERNOON WITH MAIN IMPACTS OUTSIDE OF KRWL AFTER 00Z AS WELL.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS ARE EXPECTED AT THIS TIME DUE TO SNOW
COVER IN PLACE AND COLDER AIR MOVING INTO AREAS EAST OF THE
LARAMIE RANGE SATURDAY NIGHT INTO SUNDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 5 AM MST SATURDAY FOR WYZ112.
NE...NONE.
&&
$$
SHORT TERM...TJT/JG
LONG TERM...JG
AVIATION...GCC/JG
FIRE WEATHER...REC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1021 AM MST FRI JAN 15 2016
.UPDATE...
ISSUED AT 944 AM MST FRI JAN 15 2016
SEVERAL FORECAST CONCERNS THIS MORNING THROUGH SATURDAY NIGHT AS
AN ARCTIC AIRMASS SETTLES OVER THE EASTERN PLAINS. BRIEF MODERATE
TO HEAVY SNOW SHOWERS SHOULD BE ENDING SHORTLY FURTHER WEST
BETWEEN LARAMIE AND RAWLINS AS VISIBILITIES SEEM TO HAVE INCREASE
A BIT ALONG I-80. EXPECT A BRIEF LULL THIS AFTERNOON BEFORE
ANOTHER BAND OF MODERATE TO HEAVY SNOW IS POSSIBLE FURTHER EAST
ALONG I-80...THIS TIME POTENTIALLY IMPACTING
LARAMIE...CHEYENNE...AND FURTHER EAST TOWARDS SOUTHERN NEBRASKA.
12Z MODELS HAVE STARTED TO COME IN AND SHOW THE POTENTIAL FOR
BANDED SNOW SOMEWHERE ALONG AND SOUTH OF I-80 THIS EVENING DUE TO
LLVL INSTABILITY AND FRONTOGENESIS ALONG THE LARAMIE RANGE. NOT
CONFIDENT ENOUGH ABOUT THE IMPACTS TO ISSUE A WINTER WEATHER
ADVISORY...BUT NEED TO KEEP AN EYE ON THIS THROUGH THE AFTERNOON.
12Z GFS HAS TRENDED MORE AGGRESSIVE WITH SNOWFALL SATURDAY NIGHT
AS THE ARCTIC FRONT STALLS ALONG THE LARAMIE RANGE. THE OTHER
MODELS HOWEVER ARE SHOWING LITTLE IF ANY SNOWFALL ASSOCIATED WITH
THE FRONT ACROSS THE HIGH PLAINS...SO CONFIDENCE REMAINS LOW AT
THIS TIME OUTSIDE THE MOUNTAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM MST FRI JAN 15 2016
THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE SNOW
POTENTIAL IN THE MOUNTAINS TODAY AND TONIGHT AND LIGHT SNOW
MOVING THROUGH THE WYOMING PLAINS TONIGHT.
TODAY:
LATEST RADAR/IR LOOP WAS SHOWING THE LIGHT SNOW BEGINNING
TO DIMINISH IN NATRONA COUNTY. HOWEVER...THE BANDING OF SNOW WAS
BEGINNING TO INCREASE ACROSS CONVERSE COUNTY. THE MODELS WERE
SHOWING RISING THETA SURFACES IN THE LOW LEVELS THIS MORNING. THIS
WAS HELPING STEEPEN THE LOW LEVEL LAPSE RATES AND YIELDING TO SOME
UNSTABLE CONDITIONS IN THAT REGION THIS MORNING. LATEST WEBCAMS
WERE SHOWING SOME SNOW COVERED ROADS AROUND DEER CREEK ROAD AND
POINTS WEST AS YOU HEAD TO CASPER. THE RAP/NAM SHOWS THE
SUBSIDENCE MOVING INTO THE PICTURE BY 15Z OR SO. THEREFORE...WE
DECIDED TO KEEP A CHANCE OF SNOW THIS MORNING WHICH MAY KEEP
THINGS SLICK DURING THE MORNING COMMUTE. WE ARE ALSO BEGINNING TO
SEE THE SNOW ENHANCE NEAR THE WY/NE BORDER. WEBCAMS WERE NOT
SHOWING MUCH ACCUMULATION WITH THIS SNOW DUE TO WEAK LIFT AND LACK
OF LOW LEVEL MOISTURE. MEANWHILE...THE MAIN SHOW WAS IN NORTHWEST
COLORADO WHERE THE BULK OF THE UPPER LEVEL FORCING WAS IN PLACE.
HOWEVER...OUR MOUNTAIN RANGES SHOULD BEGIN TO SEE SOME ENHANCEMENT
AS THE MORNING WEARS ON IN RESPONSE TO THE UPPER LEVEL DIVERGENCE
AND UPSLOPE FLOW. THE SNOW MAY EVEN BE QUITE HEAVY AT TIMES THIS
AFTERNOON AND THIS EVENING DUE TO DECENT LOW LEVEL LAPSE RATES
WITH ADDITIONAL ACCUMULATION OF 3 TO 6 INCHES.
TONIGHT-SATURDAY:
ANOTHER POTENTIAL VORTICITY ANOMALY IS EXPECTED TO PUSH INTO
SOUTHERN WYOMING FROM THE WEST THIS AFTERNOON WHICH MAY HELP
STEEPEN LOW LEVEL LAPSE RATES TO AROUND 8 DEG C/KM. THIS COULD
RESULT IN SOME SNOW SHOWERS ALONG THE I-80 CORRIDOR IN SOUTHERN
WYOMING LATE THIS AFTERNOON AND EVENING. AS A RESULT...WE COULD
SEE SOME BRIEF REDUCED VISIBILITIES IF THIS BANDED SNOWFALL
DEVELOPS. DAYSHIFT WILL CERTAINLY NEED TO MONITOR THIS POTENTIAL.
THE GOOD THING IS THAT IT SHOULD BE RATHER SHORTLIVED AND WIND
SPEEDS WILL BE FAIRLY LIGHT THIS AFTERNOON. THE SNOW SHOULD ALSO
BEGIN TO TAPER OFF IN THE MOUNTAINS TONIGHT.
SATURDAY NIGHT-SUNDAY NIGHT:
THE MODELS ARE ADVERTISING (ESPECIALLY THE ECMWF) THAT COLDER AIR
WILL BEGIN TO FILTER INTO THE NEBRASKA PANHANDLE ON SATURDAY NIGHT
AS A COLD FRONTAL BOUNDARY SLIDES INTO THAT REGION. THIS BOUNDARY
WILL BRING SOME LIGHT SNOW WITH IT...BUT ACCUMULATIONS ARE
EXPECTED TO BE LIGHT (1 INCH OR LESS). THERMAL CONTRAST ALONG THIS
BOUNDARY COULD BE QUITE EXTREME WITH A NEARLY 20 TO 30 DEGREE
CHANGE. THE MAIN QUESTION WILL BE HOW FAR WEST THIS BOUNDARY CAN
PENETRATE. WE FAVORED THE ECMWF SOLUTION WHICH TENDS TO HANDLE
THESE AIR MASSES THE BEST AND BRINGS THE BOUNDARY AS FAR WEST AS
THE WYOMING BORDER. WE MAY BE LOOKING AT LOW TEMPERATURES BELOW
ZERO IN PARTS OF THE PANHANDLE ON SATURDAY NIGHT AND SUNDAY NIGHT.
MEANWHILE...AREAS WEST OF THE LARAMIE RANGE MAY SEE STRONG WINDS
DEVELOP AGAIN IN RESPONSE TO A TIGHTENING 800-700MB HEIGHT
GRADIENT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 307 AM MST FRI JAN 15 2016
SOMEWHAT UNSETTLED WEATHER SEEN ACROSS THE CWA THIS PERIOD IN A
PROGRESSIVE UPPER PATTERN WITH AT LEAST A COUPLE SHORTWAVES
PASSING ACROSS THE REGION. ONE WILL APPROACH THE CWA LATE MONDAY
SPREADING SOME SNOW SHOWERS TO MAINLY THE HIGHER MTNS MONDAY
AFTERNOON THEN MORE SCTD ACTIVITY REACHING OUT OVER THE PLAINS
MONDAY NIGHT ALONG WITH A PACIFIC COLD FRONT PASSING ACROSS THE
AREA. COLDER AND MAINLY DRY TUESDAY AND TUESDAY NIGHT BEFORE THE
NEXT UPPER SHORTWAVE PASSES THROUGH THE REGION WEDNESDAY. EC MORE
AMPLIFIED WITH THIS SYSTEM AS OPPOSED TO THE GFS WHICH BASICALLY
DAMPS IT OUT ON THE FRONT SIDE OF AN UPPER RIDGE OVER THE WESTERN
CONUS. BEST CHANCE FOR SNOW SHOWERS AGAIN OVER THE HIGHER MTNS BUT
WILL KEEP SOME MENTION OF PCPN OVER THE PLAINS. DRY AND MILDER
AGAIN FOR THURSDAY AS THE UPPER RIDGE SHIFTS EAST AND OVER THE
REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1017 AM MST FRI JAN 15 2016
CONFIDENCE INCREASING THAT SNOW IS GOING TO IMPACT SEVERAL
AIRPORTS IN SOUTHEAST WYOMING AND POSSIBLY THE NORTHERN NEBRASKA
PANHANDLE. HRRR GUIDANCE SHOWING A CLIPPER SYSTEM OVER
NORTHEASTERN WYOMING MOVING SOUTHEAST BRINGING SNOW AND LOWERING
CONDITIONS TO KCDR AND KAIA. MAINLY AFTER 00Z...BUT COULD SEE IT A
LITTLE SOONER. FOR THE I-80 CORRIDOR FROM CHEYENNE TO
RAWLINS...LOOKING AT DETERIORATING CONDITIONS THROUGH THE
AFTERNOON WITH MAIN IMPACTS OUTSIDE OF KRWL AFTER 00Z AS WELL.
&&
.FIRE WEATHER...
ISSUED AT 307 AM MST FRI JAN 15 2016
NO FIRE WEATHER CONCERNS ARE EXPECTED AT THIS TIME DUE TO SNOW
COVER IN PLACE AND COLDER AIR MOVING INTO AREAS EAST OF THE
LARAMIE RANGE SATURDAY NIGHT INTO SUNDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 5 AM MST SATURDAY FOR WYZ112.
NE...NONE.
&&
$$
UPDATE...TJT
SHORT TERM...REC
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...REC