Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/23/12
AREA FORECAST DISCUSSION
NWS MIAMI FL
148 PM EDT SUN OCT 21 2012
.AVIATION...
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH FORECAST PERIOD.
NORTHEAST WINDS NEAR 10 TO 12 KNOTS WITH HIGHER GUSTS WILL PREVAIL
ACROSS EAST COAST TERMINALS THIS AFTERNOON AND AFTER OOZ WINDS
SHOULD DECREASE TO AROUND 8 TO 10 KNOTS. PRESSURE GRADIENT ACROSS
THE REGION EXPECTED TO INCREASE ON MONDAY WITH EAST COAST TERMINALS
WINDS AROUND 14-15 KNOTS AROUND 15Z WITH GUSTS TO 20-22 KNOTS
POSSIBLE. FOR TERMINAL KAPF NORTHEAST WINDS AROUND 8 KNOTS SHOULD
PREVAIL THEN INCREASING TO ABOUT 14 KNOTS BY 15Z MONDAY. EAST
COAST TERMINALS COULD HAVE PERIODS OF CEILINGS FROM 4 TO 6 KFT AS
STRATOCUMULUS STREAM IN FROM ATLANTIC WATERS.
60
&&
.PREV DISCUSSION... /ISSUED 942 AM EDT SUN OCT 21 2012/
UPDATE...
A VERY PLEASANT MORNING IS SHAPING UP FOR THE SOUTH FLORIDA AREA
UNDER MOSTLY SUNNY SKIES AND SEASONABLE TEMPERATURES. STRONG HIGH
PRESSURE CENTERED ACROSS THE APPALACHIAN STATES IS THE DOMINANT
SYNOPTIC FEATURE KEEPING THE FLORIDA PENINSULA DRY WITH NORTHERLY
FLOW. A FEW LIGHT RAIN SHOWERS ARE SEEN JUST OFF THE ATLANTIC
COAST AND ARE PUSHING SLOWLY TO THE SOUTH. ADDED A SMALL POCKET OF
ISOLATED SHOWERS ALONG THE OFFSHORE WATERS THROUGH THE AFTERNOON
HOURS. LATEST HRRR KEEPS LIGHT SHOWER ACTIVITY OFFSHORE AND
MAINLY ALONG AND SOUTH OF THE FLORIDA KEYS WHERE SLIGHTLY DEEPER
MOISTURE RESIDES.
PREV DISCUSSION... /ISSUED 727 AM EDT SUN OCT 21 2012/
AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. A LIGHT
DRAINAGE FLOW ALONG THE E CST IS ALREADY TRYING TO SHIFT TO THE NNE
SO THE MORE INLAND TERMINALS MIGHT SEE THIS SHIFT AROUND 13Z. FLOW
IS NOT NECESSARILY STRONG SO SEA BREEZE AT KAPF IS POSSIBLE.
HOWEVER, NONE OF THE SHORT TERM GUIDANCE DEPICTS THIS TO OCCUR SO
LEFT OUT OF THE FORECAST BUT THERE COULD BE A SHORT-LIVED SEA BREEZE
AROUND 19-22Z. /KOB
PREV DISCUSSION... /ISSUED 353 AM EDT SUN OCT 21 2012/
EXTENDED PERIOD...WEDNESDAY THROUGH SATURDAY...HIGH PRESSURE...
CENTERED OVER THE MID ATLC STATES WEDNESDAY...WILL SLOWLY MOVE NE
THROUGH THE WEEK AS A COLD FRONT MOVES FROM THE GREAT PLAINS EAST
-WARD TO THE ATLC COAST BY SATURDAY. AS THIS HIGH PRESSURE CENTER
MOVES NE...A SURFACE LOW OVER THE CENTRAL CARIBBEAN WILL ALSO MOVE
NE ACROSS E CUBA INTO THE ATLC AND OVER THE SOUTHERN BAHAMAS. A
TIGHT PRESSURE GRADIENT WILL REMAIN OVER S FLA WHICH WILL LEAD TO
BREEZY CONDITIONS ACROSS THE AREA THAT MAY BECOME WINDY EASTERN
ZONES IN THE LATTER PART OF THE WEEK. POPS WILL REMAIN MINIMAL
THROUGH THE PERIOD.
MARINE...
A LIGHT NORTHERLY WIND FLOW BECOMES NE TODAY AND INCREASES TO
AROUND 15 KNOTS ATLC/GULF WATERS LATE THIS AFTERNOON WHICH PERSISTS
OVERNIGHT. WINDS CONTINUE TO GRADUALLY INCREASE WITH CAUTION
CRITERIA EXPECTED MONDAY NIGHT INTO TUESDAY WITH WINDS AT ADVISORY
LEVELS FROM MIDWEEK ON. HAVE TAPERED ATLC WINDS DOWNWARD FROM GFS
GUIDANCE A BIT AS EXACT TRACK OF THE LOW PRESSURE SYSTEM NOT ETCHED
IN STONE AS OF YET.
FIRE WEATHER...
MINIMUM RELATIVE HUMIDITIES TODAY COULD FALL INTO THE MID TO UPPER
30S WEST OF LAKE OKEECHOBEE AND NORTHERN COLLIER COUNTY. AS WINDS
SHIFT NORTHEASTERLY LATE TODAY AND INTO THE WEEK...THE RELATIVE
HUMIDITIES WILL SLOWLY RISE AGAIN AS LOW LEVEL MOISTURE MOVES
ONSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 69 84 74 84 / 0 10 10 20
FORT LAUDERDALE 72 85 77 86 / - 10 10 20
MIAMI 72 86 75 86 / - 10 10 20
NAPLES 65 88 69 88 / 0 - - 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...10/CD
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
942 AM EDT SUN OCT 21 2012
.UPDATE...
A VERY PLEASANT MORNING IS SHAPING UP FOR THE SOUTH FLORIDA AREA
UNDER MOSTLY SUNNY SKIES AND SEASONABLE TEMPERATURES. STRONG HIGH
PRESSURE CENTERED ACROSS THE APPALACHIAN STATES IS THE DOMINANT
SYNOPTIC FEATURE KEEPING THE FLORIDA PENINSULA DRY WITH NORTHERLY
FLOW. A FEW LIGHT RAIN SHOWERS ARE SEEN JUST OFF THE ATLANTIC
COAST AND ARE PUSHING SLOWLY TO THE SOUTH. ADDED A SMALL POCKET OF
ISOLATED SHOWERS ALONG THE OFFSHORE WATERS THROUGH THE AFTERNOON
HOURS. LATEST HRRR KEEPS LIGHT SHOWER ACTIVITY OFFSHORE AND
MAINLY ALONG AND SOUTH OF THE FLORIDA KEYS WHERE SLIGHTLY DEEPER
MOISTURE RESIDES.
&&
.PREV DISCUSSION... /ISSUED 727 AM EDT SUN OCT 21 2012/
AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. A LIGHT
DRAINAGE FLOW ALONG THE E CST IS ALREADY TRYING TO SHIFT TO THE NNE
SO THE MORE INLAND TERMINALS MIGHT SEE THIS SHIFT AROUND 13Z. FLOW
IS NOT NECESSARILY STRONG SO SEA BREEZE AT KAPF IS POSSIBLE.
HOWEVER, NONE OF THE SHORT TERM GUIDANCE DEPICTS THIS TO OCCUR SO
LEFT OUT OF THE FORECAST BUT THERE COULD BE A SHORT-LIVED SEA BREEZE
AROUND 19-22Z. /KOB
PREV DISCUSSION... /ISSUED 353 AM EDT SUN OCT 21 2012/
EXTENDED PERIOD...WEDNESDAY THROUGH SATURDAY...HIGH PRESSURE...
CENTERED OVER THE MID ATLC STATES WEDNESDAY...WILL SLOWLY MOVE NE
THROUGH THE WEEK AS A COLD FRONT MOVES FROM THE GREAT PLAINS EAST
-WARD TO THE ATLC COAST BY SATURDAY. AS THIS HIGH PRESSURE CENTER
MOVES NE...A SURFACE LOW OVER THE CENTRAL CARIBBEAN WILL ALSO MOVE
NE ACROSS E CUBA INTO THE ATLC AND OVER THE SOUTHERN BAHAMAS. A
TIGHT PRESSURE GRADIENT WILL REMAIN OVER S FLA WHICH WILL LEAD TO
BREEZY CONDITIONS ACROSS THE AREA THAT MAY BECOME WINDY EASTERN
ZONES IN THE LATTER PART OF THE WEEK. POPS WILL REMAIN MINIMAL
THROUGH THE PERIOD.
MARINE...
A LIGHT NORTHERLY WIND FLOW BECOMES NE TODAY AND INCREASES TO
AROUND 15 KNOTS ATLC/GULF WATERS LATE THIS AFTERNOON WHICH PERSISTS
OVERNIGHT. WINDS CONTINUE TO GRADUALLY INCREASE WITH CAUTION
CRITERIA EXPECTED MONDAY NIGHT INTO TUESDAY WITH WINDS AT ADVISORY
LEVELS FROM MIDWEEK ON. HAVE TAPERED ATLC WINDS DOWNWARD FROM GFS
GUIDANCE A BIT AS EXACT TRACK OF THE LOW PRESSURE SYSTEM NOT ETCHED
IN STONE AS OF YET.
FIRE WEATHER...
MINIMUM RELATIVE HUMIDITIES TODAY COULD FALL INTO THE MID TO UPPER
30S WEST OF LAKE OKEECHOBEE AND NORTHERN COLLIER COUNTY. AS WINDS
SHIFT NORTHEASTERLY LATE TODAY AND INTO THE WEEK...THE RELATIVE
HUMIDITIES WILL SLOWLY RISE AGAIN AS LOW LEVEL MOISTURE MOVES
ONSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 69 84 74 / - 0 10 10
FORT LAUDERDALE 84 72 85 77 / - - 10 10
MIAMI 85 72 86 75 / - - 10 10
NAPLES 87 65 88 69 / - 0 - -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...10/CD
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
844 PM CDT MON OCT 22 2012
.DISCUSSION...
ISSUED 844 PM CDT MON OCT 22 2012
NO MAJOR FORECAST CHANGES ANTICIPATED THIS EVENING...AS CENTRAL
ILLINOIS REMAINS SANDWICHED BETWEEN TWO WEATHER SYSTEMS. THE FIRST
SHORT-WAVE THAT BROUGHT WIDESPREAD SHOWERS/STORMS TO THE AREA
EARLIER TODAY IS NOW WELL TO THE NORTHEAST OVER THE SOUTHERN GREAT
LAKES...WHILE THE SECOND WAVE IS STILL UPSTREAM ACROSS EASTERN
KANSAS/OKLAHOMA. THIS SECOND FEATURE WILL EVENTUALLY TRIGGER A
RENEWED ROUND OF SHOWERS/THUNDER ACROSS CENTRAL ILLINOIS...BUT NOT
UNTIL LATE TONIGHT INTO TUESDAY MORNING. WITH AN OVERALL LACK OF
FORCING DUE TO SHORT-WAVE RIDGING...ONLY ISOLATED SHOWERS ARE
EXPECTED THROUGH MIDNIGHT. ONCE KANSAS WAVE BEGINS TO
APPROACH...INCREASING SYNOPTIC LIFT WILL LEAD TO THE DEVELOPMENT
OF SCATTERED SHOWERS AND THUNDERSTORMS TOWARD DAWN. CURRENT
FORECAST PACKAGE HANDLES THIS QUITE WELL...SO NO ZONE UPDATE IS
NEEDED AT THIS TIME.
BARNES
&&
.AVIATION...
ISSUED 633 PM CDT MON OCT 22 2012
SHORT-WAVE RIDGING IN THE WAKE OF A SYSTEM NOW OVER SOUTHERN LAKE
MICHIGAN WILL LEAD TO A LULL IN THE PRECIP ACROSS MUCH OF CENTRAL
ILLINOIS THIS EVENING. THE EXCEPTION MAY BE ACROSS THE FAR
NORTHERN KILX CWA...WHERE THE HRRR SUGGESTS SCATTERED SHOWERS WILL
DEVELOP ALONG/NEAR A SURFACE TROUGH EXTENDING ACROSS NORTH-CENTRAL
ILLINOIS. HAVE INCLUDED VCSH AT KPIA BETWEEN 02Z AND 05Z ACCORDINGLY.
ADDITIONAL CONVECTION CURRENTLY DEVELOPING WEST OF THE SAINT LOUIS
AREA WILL TRACK E/NE THIS EVENING...AND GENERALLY STAY SOUTH OF
THE KILX TERMINALS. NEXT ROUND OF RENEWED CONVECTION WILL LIKELY
HOLD OFF UNTIL VERY LATE TONIGHT INTO TUESDAY MORNING...AS SHORT-WAVE
TROUGH CURRENTLY OVER OKLAHOMA LIFTS NORTHEASTWARD THROUGH THE
AREA. STILL DIFFICULT TO DETERMINE EXACT TIMING AND AREAL COVERAGE
WITH THIS SECOND ROUND OF PRECIP...SO HAVE ONLY INCLUDED VCTS FROM
AROUND DAWN INTO EARLY TO MID-AFTERNOON. AFTER THAT...WAVE WILL
SHIFT OFF TO THE EAST AND ANY PRECIP WILL COME TO AN END BY LATE
TUESDAY AFTERNOON. CEILINGS WILL GENERALLY REMAIN IN THE VFR
CATEGORY THROUGH THE ENTIRE PERIOD...BUT COULD DROP TO MVFR IN
THUNDERSTORMS. WINDS WILL BE SOUTHERLY AT AROUND 10KT.
BARNES
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT MON OCT 22 2012
THE UPPER LEVEL RIDGE AXIS HAS SHIFTED EAST OF ILLINOIS SETTING UP
SOUTHWEST FLOW INTO ILLINOIS. AIDED BY A STRONG LOW LEVEL JET
/LLJ/... MOISTURE AND WARM AIR WILL CONTINUE TO SURGE NORTHWARD
INTO C IL TONIGHT AND THE NEXT FEW DAYS. ABOVE NORMAL TEMPS WILL
BE THE RULE UNTIL THE COLD FRONT ARRIVES THURSDAY NIGHT AND GETS A
SHOVE TO THE SOUTHEAST ON FRIDAY NIGHT. MUCH COOLER AIR WILL BE
THE RULE FOR THE WEEKEND AND EARLY NEXT WEEK...WITH HIGHS ON
SATURDAY ONLY IN THE LOW 50S.
SHORT TERM...TONIGHT THROUGH WEDNESDAY.
THE SHOWERS AND STORMS FROM THE INITIAL MCV HAVE PUSHED OUT OF
NEARLY ALL OF OUR AREA EXCEPT ALONG AND SOUTH OF I-70. A BREAK IN
THE ACTION IS EXPECTED FOR THE REMAINDER OF THE AREA UNTIL THE
NEXT UPPER SHORTWAVE ARRIVES TONIGHT. IT WILL TRIGGER OUR NEXT
ROUND OF SHOWERS AND STORMS AFTER MIDNIGHT AND INTO TUESDAY
MORNING. INSTABILITY AND SHEAR PARAMS SHOULD SUPPORT STRONG
STORMS...BUT LITTLE TO NO SEVERE WEATHER IS EXPECTED. HAIL WOULD
BE THE PRIMARY HAZARD WITH THE STRONGEST STORMS.
WE KEPT HIGH CHANCE POPS GOING TUESDAY MORNING IN OUR NORTHEAST
COUNTIES...BEFORE THE SHORTWAVE MOVES OFF TO THE NORTHEAST TUES
AFTN. THEN A DRY PERIOD IS EXPECTED FROM TUES AFTERNOON THROUGH
THURSDAY MORNING...WHEN WE SEE OUR WARMEST HIGHS OF THE WEEK. WED
SHOULD SEE 850MB TEMPS CLIMB INTO THE 16-18C RANGE. ADIABATIC
WARMING WOULD PUT HIGHS IN THE LOWER 80S IF THAT OCCURS.
LONG TERM...THURSDAY THROUGH MONDAY.
INCREASING CLOUDS AND THE ARRIVAL OF THE COLD FRONT ON THURS WILL
WORK TO CAP HIGH TEMPS IN THE MID TO UPPER 70S. THERE ARE STILL
TIMING DIFFERENCES BETWEEN THE MODELS...WITH NAM THE SLOWEST AND
THE GFS THE FASTEST. THE CANADIAN AND ECMWF ARE THE MID-GROUND.
THE CONSENSUS OF THE FASTER 3 IS FOR THE FRONT TO REACH NEAR
BMI/CMI BY 7PM THURSDAY. WE KEPT SOME LOW CHANCE POPS IN THE FAR NW
THUR MORN AND EXPANDED POPS TO THE SE THURS AFTN. WITH MOST OF THE
PRECIP BEGIN POST-FRONTAL...WE MAY REMAIN DRY UNTIL LATER
AFTERNOON NORTHWEST OF THE IL RIVER.
MOISTURE LEVELS AND FRONTAL DYNAMICS LOOK FAVORABLE FOR SOME
LOCALLY HEAVY RAIN THURSDAY NIGHT BEHIND THE FRONT. THE FRONT IS
EXPECTED TO SLOW DOWN AS IT DEPARTS TO THE SOUTHEAST. THEN A
SECONDARY SHORTWAVE IS FORECAST TO LIFT NORTHEAST ON THE NORTH
SIDE OF THE FRONT FRIDAY NIGHT...BRINGING A CHANCE OF MORE RAIN TO
AT LEAST AREAS SOUTHEAST OF I-55. THE PATH OF THAT WAVE HAS
SHIFTED FARTHER TO THE SOUTHEAST WITH THE 12Z RUN OF THE GFS AND
CANADIAN. THE ECMWF HAS THE FARTHEST NW TRACK OF THE EXTENDED
MODELS. WE KEPT LIKELY POPS FOR FRI NIGHT WHEN THE WAVE REACHES
ITS CLOSEST POINT TO CENTRAL/SOUTHEAST IL. SOME LINGERING SHOWERS
ON SATURDAY MORNING SHOULD END BY NOON SATURDAY.
THE COLD AIR WILL ARRIVE BEHIND THAT FRIDAY NIGHT SHORTWAVE...SO
HIGHS ON SATURDAY WILL STRUGGLE TO REACH THE LOWER 50S ON BRISK
NORTHWEST WINDS. THE COLD AIR WILL DROP LOWS INTO THE LOW TO MID
30S EACH NIGHT FROM SAT NIGHT THROUGH MONDAY NIGHT...WITH DAYTIME
HIGHS AROUND 50...10-14 DEG F BELOW NORMAL. AT LEAST NEXT WEEKEND
AND MONDAY LOOKS DRY FOR THE MAJORITY OF THE TIME AFTER SATURDAY
MORNINGS SHOWERS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
633 PM CDT MON OCT 22 2012
.DISCUSSION...
ISSUED 300 PM CDT MON OCT 22 2012
THE UPPER LEVEL RIDGE AXIS HAS SHIFTED EAST OF ILLINOIS SETTING UP
SOUTHWEST FLOW INTO ILLINOIS. AIDED BY A STRONG LOW LEVEL JET
/LLJ/... MOISTURE AND WARM AIR WILL CONTINUE TO SURGE NORTHWARD
INTO C IL TONIGHT AND THE NEXT FEW DAYS. ABOVE NORMAL TEMPS WILL
BE THE RULE UNTIL THE COLD FRONT ARRIVES THURSDAY NIGHT AND GETS A
SHOVE TO THE SOUTHEAST ON FRIDAY NIGHT. MUCH COOLER AIR WILL BE
THE RULE FOR THE WEEKEND AND EARLY NEXT WEEK...WITH HIGHS ON
SATURDAY ONLY IN THE LOW 50S.
SHORT TERM...TONIGHT THROUGH WEDNESDAY.
THE SHOWERS AND STORMS FROM THE INITIAL MCV HAVE PUSHED OUT OF
NEARLY ALL OF OUR AREA EXCEPT ALONG AND SOUTH OF I-70. A BREAK IN
THE ACTION IS EXPECTED FOR THE REMAINDER OF THE AREA UNTIL THE
NEXT UPPER SHORTWAVE ARRIVES TONIGHT. IT WILL TRIGGER OUR NEXT
ROUND OF SHOWERS AND STORMS AFTER MIDNIGHT AND INTO TUESDAY
MORNING. INSTABILITY AND SHEAR PARAMS SHOULD SUPPORT STRONG
STORMS...BUT LITTLE TO NO SEVERE WEATHER IS EXPECTED. HAIL WOULD
BE THE PRIMARY HAZARD WITH THE STRONGEST STORMS.
WE KEPT HIGH CHANCE POPS GOING TUESDAY MORNING IN OUR NORTHEAST
COUNTIES...BEFORE THE SHORTWAVE MOVES OFF TO THE NORTHEAST TUES
AFTN. THEN A DRY PERIOD IS EXPECTED FROM TUES AFTERNOON THROUGH
THURSDAY MORNING...WHEN WE SEE OUR WARMEST HIGHS OF THE WEEK. WED
SHOULD SEE 850MB TEMPS CLIMB INTO THE 16-18C RANGE. ADIABATIC
WARMING WOULD PUT HIGHS IN THE LOWER 80S IF THAT OCCURS.
LONG TERM...THURSDAY THROUGH MONDAY.
INCREASING CLOUDS AND THE ARRIVAL OF THE COLD FRONT ON THURS WILL
WORK TO CAP HIGH TEMPS IN THE MID TO UPPER 70S. THERE ARE STILL
TIMING DIFFERENCES BETWEEN THE MODELS...WITH NAM THE SLOWEST AND
THE GFS THE FASTEST. THE CANADIAN AND ECMWF ARE THE MID-GROUND.
THE CONSENSUS OF THE FASTER 3 IS FOR THE FRONT TO REACH NEAR
BMI/CMI BY 7PM THURSDAY. WE KEPT SOME LOW CHANCE POPS IN THE FAR NW
THUR MORN AND EXPANDED POPS TO THE SE THURS AFTN. WITH MOST OF THE
PRECIP BEGIN POST-FRONTAL...WE MAY REMAIN DRY UNTIL LATER
AFTERNOON NORTHWEST OF THE IL RIVER.
MOISTURE LEVELS AND FRONTAL DYNAMICS LOOK FAVORABLE FOR SOME
LOCALLY HEAVY RAIN THURSDAY NIGHT BEHIND THE FRONT. THE FRONT IS
EXPECTED TO SLOW DOWN AS IT DEPARTS TO THE SOUTHEAST. THEN A
SECONDARY SHORTWAVE IS FORECAST TO LIFT NORTHEAST ON THE NORTH
SIDE OF THE FRONT FRIDAY NIGHT...BRINGING A CHANCE OF MORE RAIN TO
AT LEAST AREAS SOUTHEAST OF I-55. THE PATH OF THAT WAVE HAS
SHIFTED FARTHER TO THE SOUTHEAST WITH THE 12Z RUN OF THE GFS AND
CANADIAN. THE ECMWF HAS THE FARTHEST NW TRACK OF THE EXTENDED
MODELS. WE KEPT LIKELY POPS FOR FRI NIGHT WHEN THE WAVE REACHES
ITS CLOSEST POINT TO CENTRAL/SOUTHEAST IL. SOME LINGERING SHOWERS
ON SATURDAY MORNING SHOULD END BY NOON SATURDAY.
THE COLD AIR WILL ARRIVE BEHIND THAT FRIDAY NIGHT SHORTWAVE...SO
HIGHS ON SATURDAY WILL STRUGGLE TO REACH THE LOWER 50S ON BRISK
NORTHWEST WINDS. THE COLD AIR WILL DROP LOWS INTO THE LOW TO MID
30S EACH NIGHT FROM SAT NIGHT THROUGH MONDAY NIGHT...WITH DAYTIME
HIGHS AROUND 50...10-14 DEG F BELOW NORMAL. AT LEAST NEXT WEEKEND
AND MONDAY LOOKS DRY FOR THE MAJORITY OF THE TIME AFTER SATURDAY
MORNINGS SHOWERS.
&&
.AVIATION...
ISSUED 633 PM CDT MON OCT 22 2012
SHORT-WAVE RIDGING IN THE WAKE OF A SYSTEM NOW OVER SOUTHERN LAKE
MICHIGAN WILL LEAD TO A LULL IN THE PRECIP ACROSS MUCH OF CENTRAL
ILLINOIS THIS EVENING. THE EXCEPTION MAY BE ACROSS THE FAR
NORTHERN KILX CWA...WHERE THE HRRR SUGGESTS SCATTERED SHOWERS WILL
DEVELOP ALONG/NEAR A SURFACE TROUGH EXTENDING ACROSS NORTH-CENTRAL
ILLINOIS. HAVE INCLUDED VCSH AT KPIA BETWEEN 02Z AND 05Z ACCORDINGLY.
ADDITIONAL CONVECTION CURRENTLY DEVELOPING WEST OF THE SAINT LOUIS
AREA WILL TRACK E/NE THIS EVENING...AND GENERALLY STAY SOUTH OF
THE KILX TERMINALS. NEXT ROUND OF RENEWED CONVECTION WILL LIKELY
HOLD OFF UNTIL VERY LATE TONIGHT INTO TUESDAY MORNING...AS SHORT-WAVE
TROUGH CURRENTLY OVER OKLAHOMA LIFTS NORTHEASTWARD THROUGH THE
AREA. STILL DIFFICULT TO DETERMINE EXACT TIMING AND AREAL COVERAGE
WITH THIS SECOND ROUND OF PRECIP...SO HAVE ONLY INCLUDED VCTS FROM
AROUND DAWN INTO EARLY TO MID-AFTERNOON. AFTER THAT...WAVE WILL
SHIFT OFF TO THE EAST AND ANY PRECIP WILL COME TO AN END BY LATE
TUESDAY AFTERNOON. CEILINGS WILL GENERALLY REMAIN IN THE VFR
CATEGORY THROUGH THE ENTIRE PERIOD...BUT COULD DROP TO MVFR IN
THUNDERSTORMS. WINDS WILL BE SOUTHERLY AT AROUND 10KT.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
256 AM CDT SUN OCT 21 2012
.DISCUSSION...
ISSUED 255 AM CDT SUN OCT 21 2012
LATEST SURFACE MAP SHOWED HIGH PRESSURE CENTERED OVER EASTERN
PARTS OF KENTUCKY AND TENNESSEE. LITTLE IN THE WAY OF CLOUD COVER
OVER ILLINOIS...WITH JUST SOME MID AND HIGH CLOUDS IN THE FAR
NORTH AND FAR SOUTH.
THE MAIN FORECAST CONCERNS FOR THIS PACKAGE INCLUDE THE EXTENT OF
THE UNSEASONABLY WARM WEATHER THIS WEEK...AS WELL AS TIMING OF
SHOWERS AND THUNDERSTORMS TONIGHT AND MONDAY AND AGAIN LATER THIS
WEEK.
SHORT TERM...TODAY THROUGH WEDNESDAY...
FAIRLY SHARP THERMAL GRADIENT AT 850 MB NOTED ON EVENING UPPER AIR
ANALYSIS...WITH TEMPERATURES RANGING FROM 5C AT LINCOLN AND
DAVENPORT TO THE MID TEENS IN WESTERN IOWA/MISSOURI. LATEST LAPS
ANALYSIS SHOWING TEMPS OF 10C ALREADY MOVING INTO THE FAR WESTERN
CWA AS PROGGED BY THE 00Z NAM...AND ANOTHER 5 DEGREE RISE IS EXPECTED
BY AFTERNOON. SURFACE TEMPS STILL LOOK LIKELY TO REACH THE 70-75
RANGE TODAY...WARMEST WEST...AND WILL HEAD TOWARD THE 80 DEGREE
RANGE MONDAY AND ESPECIALLY ON TUESDAY AND WEDNESDAY.
LOW PRESSURE DEVELOPING OVER THE CENTRAL PLAINS EARLY THIS MORNING
WILL BEGIN TO LIFT NORTHEAST ON MONDAY. EVENING MODEL SUITE KEEPS
THE MAIN WARM FRONT WELL TO OUR NORTH EARLY THIS WEEK...BUT AN
UPPER WAVE AND STRENGTHENING LOW LEVEL JET WILL HELP DEVELOP SOME
CONVECTION TO OUR WEST LATER THIS EVENING...WHICH WILL SPREAD
NORTHEASTWARD OVERNIGHT. WILL CONTINUE WITH BEST SHOWER/STORM
CHANCES WEST OF I-55 LATE TONIGHT AND OVER ABOUT THE NORTHWEST 2/3
OF THE CWA THROUGH EARLY MONDAY AFTERNOON. BUFKIT DATA SHOWING
ELEVATED CAPES OVER 1000 J/KG BY LATE TONIGHT...SO A FEW STRONGER
STORMS ARE NOT OUT OF THE QUESTION...ALTHOUGH SEVERE WEATHER
THREAT PER LATEST SPC CONVECTIVE OUTLOOKS IS ONLY AROUND 5
PERCENT. AFTER THAT...MAINLY DRY CONDITIONS ARE EXPECTED TUESDAY
AND WEDNESDAY.
LONG TERM...THURSDAY THROUGH SATURDAY...
SOME SPREAD AMONG THE MODELS BECOMES MORE APPARENTLY BY MIDWEEK...
WITH REGARD TO THE BROAD UPPER TROUGHING THAT WILL TAKE SHAPE
ACROSS THE WESTERN UNITED STATES. THE GFS IS FASTEST IN CUTTING
OFF A LARGE UPPER LOW OVER SASKATCHEWAN BY MIDDAY WEDNESDAY...
WHEREAS THE ECMWF AND CANADIAN MODELS WAIT UNTIL LATE THURSDAY
NIGHT OVER MINNESOTA. THIS RESULTS IN SOME TIMING DIFFERENCES IN
STARTING THE NEXT ROUND OF SHOWERS/STORMS WITH THE ASSOCIATED COLD
FRONT. HAVE KEPT SOME SMALL CHANCES WEST OF THE ILLINOIS RIVER
WEDNESDAY NIGHT...THEN CONTINUED WITH INCREASING CHANCES OVER THE
CENTRAL AND WESTERN CWA ON THURSDAY AND ACROSS THE EAST THURSDAY
NIGHT. WHILE ALL OF THE MODELS HAVE THE FRONT THROUGH THE AREA ON
FRIDAY AND THE RAIN THREAT PASSED...HAVE KEPT SLIGHT CHANCES FOR
NOW AS THE CONSISTENCY OF SOME OF THE MODELS HAS NOT BEEN IDEAL
THE LAST FEW RUNS.
SHARPENING SHORTWAVE OVER THE PLAINS LATE FRIDAY WILL HELP DEVELOP
ADDITIONAL RAINFALL ON THE NORTH SIDE OF THE BOUNDARY. HAVE ADDED
RAIN CHANCES TO THE ENTIRE AREA FRIDAY NIGHT...AND ACROSS THE
SOUTHEAST HALF ON SATURDAY.
TEMPERATURE-WISE...WILL LIKELY SEE 70S CONTINUE INTO THURSDAY
WITH THE SLOWER TREND IN THE FRONT. THE WEEKEND STILL LOOKS
CHILLY...WITH HIGHS ON SATURDAY IN THE UPPER 40S TO LOWER 50S.
HOWEVER...THE GFS SOLUTION IS QUITE A BIT COOLER THAN THE
ECMWF...WITH 850 MB TEMPS DOWN TO AROUND -7C...SO THE POTENTIAL IS
THERE FOR EVEN LOWER TEMPERATURES LATER IN THE WEEKEND.
GEELHART
&&
.AVIATION...
ISSUED 1150 PM CDT SAT OCT 20 2012
VFR CONDITIONS EXPECTED TO CONTINUE EARLY OVERNIGHT ACROSS THE
CENTRAL IL AIRPORTS. PATCHY FOG EXPECTED TO DEVELOP AFTER 08Z/3
AM WITH MVFR VSBYS POSSIBLE ESPECIALLY AT DEC AND CMI WHERE SSE
WINDS STAY LIGHTER LONGER TONIGHT. THIS DUE TO MOIST BOUNDARY LAYER
(WITH CURRENT TEMP/DEWPOINT SPREAD OF ABOUT 4F AND DOWN TO 2F AT
DEC) TO SUPPORT PATCHY FOG DEVELOP LATER TONIGHT UNTIL 14Z/9 AM
SUNDAY MORNING...THOUGH RETURN SSE WINDS INCREASING TO 5-10 KTS
DURING OVERNIGHT SHOULD LIMIT EXTENT AND DENSENESS OF FOG. NAM
HITS THE FOG HARDEST LATER TONIGHT WHILE GFS AND HRRR MODELS OUT
TO 12Z/7 AM IS NOT AS WIDESPREAD WITH THE FOG (HRRR VSBY MAINLY
5-6 MILES). MOST MODELS LIFT ANY FOG THAT DEVELOPS BY 14Z/9 AM
SUNDAY. FEW CUMULUS CLOUDS APPEAR AFTER 15Z/10 AM SUNDAY WITH
SCATTERED THIN CIRRUS CLOUDS MOVING INTO CENTRAL IL LATER TONIGHT
AND SUNDAY. BROKEN CUMULUS CLOUDS OF 4-5K FT TO SPREAD NE FROM MO
ACROSS CENTRAL IL BETWEEN 02Z-04Z SUNDAY EVENING PER GFS AND NAM
FORECAST SOUNDINGS (REACHING SPI FIRST AND CMI LAST). WEAK 1017 MB
SURFACE HIGH PRESSURE OVER THE EASTERN OH/TN VALLEYS TO DRIFT EAST
INTO THE MID ATLANTIC STATES BY SUNDAY EVENING WITH INCREASING SSE
FLOW OVER CENTRAL IL LATER TONIGHT AND ESPECIALLY DURING THE DAY
SUNDAY. EXPECT SSE WINDS OF 10-14 KTS AFTER 15Z/10 AM SUNDAY AND
GUSTS 15-19 KTS SUNDAY AFTERNOON. MOST MODELS KEEP CENTRAL IL DRY
THROUGH 06Z/1 AM MON WITH WARM AIR/MOISTURE ADVECTION SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING FROM SW TO NE ACROSS
CENTRAL IL DURING OVERNIGHT SUNDAY NIGHT... JUST BEYOND THIS 24
HOUR TAF FORECAST.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1155 PM CDT SAT OCT 20 2012
.DISCUSSION...
ISSUED 900 PM CDT SAT OCT 20 2012
FORECAST LOOKS ON TRACK TONIGHT AND JUST A FEW MINOR UPDATES DONE.
STILL HAVE A NARROW BAND OF CUMULUS/STRATOCUMULUS CLOUDS WITH 3-4K
FOOT BASES SE OF DECATUR AND CHAMPAIGN TO THE WABASH RIVER. THESE
CLOUDS SHOULD DISSIPATE BY MIDNIGHT AT IT DRIFTS SLOWLY NE INTO
EAST CENTRAL IL. KEEPING PATCHY FOG OVERNIGHT UNTIL 9 AM
SUNDAY...AND ALSO ADDING AREAS OF FOG LATER TONIGHT OVER PARTS OF
EAST CENTRAL IL WHERE SSE WINDS STAY LIGHTER LONGER DURING
TONIGHT. LOWS IN THE LOWER 40S LOOK ON TRACK WITH LIGHT SSE WINDS
INCREASING TO 5-10 MPH TOWARD DAYBREAK.
WEAK 1017 MB HIGH PRESSURE OVER THE EASTERN OHIO VALLEY INTO MID
TN AND AL AND RIDGING INTO NE IL AND WI AT MID EVENING. HIGH
PRESSURE WAS BRINGING CLEAR SKIES ACROSS IL EXCEPT FOR THAT NARROW
BAND OF LOW CLOUDS SE OF DECATUR/CHAMPAIGN. HIGH PRESSURE TO DRIFT
EAST INTO THE CENTRAL APPLACHIANS BY DAWN SUNDAY AND MID ATLANTIC
STATES BY SUNSET SUNDAY AS UPPER LEVEL RIDGE BUILDS EAST INTO IL.
LIGHT WINDS THIS EVENING TO BECOME SSE 5-10 MPH BY DAWN SUNDAY AND
BE STRONGEST OVER WESTERN IL WHICH WILL KEEP FOG FROM FORMING AS
MUCH. EASTERN IL WILL LIKELY SEE THE MOST FOG DEVELOP AFTER 2 AM
AND DISSIPATE BY 9 AM SUNDAY. DID NOT MENTION DENSE FOG AT THIS
TIME DUE TO SSE WINDS INCREASING A BIT LATER TONIGHT. TEMPS
CURRENTLY IN THE MID 40S TO LOWER 50S AND SHOULD SETTLE TOWARD THE
DEWPOINTS IN THE LOW TO MID 40S FOR LOWS BY DAYBREAK AND COOLEST
OVER EAST CENTRAL IL.
07
&&
.AVIATION...
ISSUED 1150 PM CDT SAT OCT 20 2012
VFR CONDITIONS EXPECTED TO CONTINUE EARLY OVERNIGHT ACROSS THE
CENTRAL IL AIRPORTS. PATCHY FOG EXPECTED TO DEVELOP AFTER 08Z/3
AM WITH MVFR VSBYS POSSIBLE ESPECIALLY AT DEC AND CMI WHERE SSE
WINDS STAY LIGHTER LONGER TONIGHT. THIS DUE TO MOIST BOUNDARY LAYER
(WITH CURRENT TEMP/DEWPOINT SPREAD OF ABOUT 4F AND DOWN TO 2F AT
DEC) TO SUPPORT PATCHY FOG DEVELOP LATER TONIGHT UNTIL 14Z/9 AM
SUNDAY MORNING...THOUGH RETURN SSE WINDS INCREASING TO 5-10 KTS
DURING OVERNIGHT SHOULD LIMIT EXTENT AND DENSENESS OF FOG. NAM
HITS THE FOG HARDEST LATER TONIGHT WHILE GFS AND HRRR MODELS OUT
TO 12Z/7 AM IS NOT AS WIDESPREAD WITH THE FOG (HRRR VSBY MAINLY
5-6 MILES). MOST MODELS LIFT ANY FOG THAT DEVELOPS BY 14Z/9 AM
SUNDAY. FEW CUMULUS CLOUDS APPEAR AFTER 15Z/10 AM SUNDAY WITH
SCATTERED THIN CIRRUS CLOUDS MOVING INTO CENTRAL IL LATER TONIGHT
AND SUNDAY. BROKEN CUMULUS CLOUDS OF 4-5K FT TO SPREAD NE FROM MO
ACROSS CENTRAL IL BETWEEN 02Z-04Z SUNDAY EVENING PER GFS AND NAM
FORECAST SOUNDINGS (REACHING SPI FIRST AND CMI LAST). WEAK 1017 MB
SURFACE HIGH PRESSURE OVER THE EASTERN OH/TN VALLEYS TO DRIFT EAST
INTO THE MID ATLANTIC STATES BY SUNDAY EVENING WITH INCREASING SSE
FLOW OVER CENTRAL IL LATER TONIGHT AND ESPECIALLY DURING THE DAY
SUNDAY. EXPECT SSE WINDS OF 10-14 KTS AFTER 15Z/10 AM SUNDAY AND
GUSTS 15-19 KTS SUNDAY AFTERNOON. MOST MODELS KEEP CENTRAL IL DRY
THROUGH 06Z/1 AM MON WITH WARM AIR/MOISTURE ADVECTION SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING FROM SW TO NE ACROSS
CENTRAL IL DURING OVERNIGHT SUNDAY NIGHT... JUST BEYOND THIS 24
HOUR TAF FORECAST.
07
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT SAT OCT 20 2012
INITIAL CONCERNS WILL BE FOR FOG TO FORM TONIGHT IN THE WAKE OF
THE DEPARTING LOW. THEN ATTENTION TURNS TO THE DRAMATIC WARM-UP
AND PERIODIC RAIN CHANCES AS A COUPLE OF LOW PRESSURE SYSTEMS LIFT
THROUGH THE PLAINS NEXT WEEK. AN AIRMASS CHANGE BACK TO COOLER
WEATHER WILL BEGIN WITH A LATE WEEK COLD FRONT...STARTING A PERIOD
OF BELOW NORMAL TEMPS.
SHORT TERM...TONIGHT THROUGH WEDNESDAY.
BREAKS HAVE DEVELOPED IN THE CLOUD COVER THE LAST COUPLE
HOURS...DUE TO MIXING OF DRY AIR FROM ALOFT. THE MOST CLEARING
HAS OCCURRED NORTH OF I-74...WHERE CLEARING LAST NIGHT ALLOWED FOR
SOME DENSE FOG TO FORM.
WE EXPECT ENOUGH CLEARING BY EVENING THAT RADIATIONAL COOLING
WILL PUSH TEMPS DOWN TO THE WET-BULB TEMPS OVERNIGHT. NAM FORECAST
SOUNDINGS ARE INDICATING FOG AND STRATUS WILL LIKELY FORM. THE
HIGH RESOLUTION RAPID REFRESH /HRRR/ MODEL OUTPUT IS SHOWING
STRATUS/FOG FORMING ALREADY DURING THE EVENING. WE WILL BE ADDING
FOG TO THE FORECAST FOR TONIGHT INTO EARLY SUNDAY MORNING...SOME
OF THE FOG MAY BECOME LOCALLY DENSE.
THE FOG SHOULD BURN OFF BY 9AM ON SUNDAY...WITH SUNSHINE AS WE
HEAD INTO THE AFTERNOON. MID LEVEL WARM ADVECTION WILL CRANK UP
SUNDAY AFTERNOON...BRINGING SOME SCATTERED MID CLOUDS. THAT MAY
KEEP HIGHS A LITTLE LOWER THAN FULL SUN...BUT WE STILL EXPECT
TEMPS TO RANGE FROM MID 70S IN THE SW TO AROUND 70 IN THE NE.
LOW PRESSURE IN THE PLAINS WILL APPROACH NORTHWEST MISSOURI BY 12Z
MONDAY...WITH SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLY AFFECTING
OUR WESTERN COUNTIES SUN NIGHT. THE NAM AND ECMWF KEEP OUR
COUNTIES RELATIVELY DRY UNTIL LATE...BUT THE CANADIAN AND GFS
CONTINUE TO BE MORE AGGRESSIVE WITH PRECIP. WE KEPT A MENTION OF
PRECIP...BUT TRIMMED THE EASTERN EDGE OF THE POPS.
WARM FRONTOGENESIS DEVELOPS ACROSS NORTHERN ILLINOIS ON MONDAY AS
THE SURFACE LOW SLOWLY LIFTS INTO IOWA. THE LOW WILL CONTINUE
MOVING NORTHEAST INTO WISCONSIN BY TUESDAY...KEEPING OUR AREA IN
THE WARM SECTOR AND FIRMLY IN THE THERMAL RIDGE. HOWEVER...THE
PROXIMITY OF THE ASSOCIATED FRONTAL BOUNDARIES AND WEAK SHORTWAVES
IN THE UPPER FLOW WILL KEEP RAIN AND STORM CHANCES IN OUR FORECAST
FOR MONDAY AND MONDAY NIGHT. WE PULLED POPS BACK TO JUST SLIGHT
CHANCE ON TUESDAY...AS THE WARM FRONT ADVANCES NORTH INTO
WISCONSIN/MICHIGAN.
THE WARM FRONT WILL LIFT TOWARD UPPER MICHIGAN ON
WEDNESDAY...HELPING OUR AREA REMAIN DRY WITH SUNSHINE. 850 MB
TEMPS SHOULD CLIMB INTO THE 16-17C RANGE. ADIABATIC WARMING SHOULD
PUSH HIGH TEMPS TO NEAR 80 AROUND JACKSONVILLE...WITH MID TO
UPPER 70S COMMON.
LONG TERM...THURSDAY THROUGH SATURDAY.
A COLD FRONT WAS EXPECTED TO PASS ACROSS OUR AREA ON
THURSDAY...BUT THE 12Z GFS SLOWED THE FRONT DOWN BY 12 HOURS...AND
THE 12Z ECMWF DELAYED IT BY 6 HOURS. THE GFS NOW SHOWS A DRY DAY
ON THURSDAY...WHILE THE ECMWF HAS SOME SHOWERS AND STORMS NW OF
I-55 IN THE AFTERNOON. WE KEPT THE ALL-BLEND POPS FROM THE 00Z
ECMWF/12Z GFS WHICH ARE LOWER THAN PREVIOUS RUNS. HOWEVER...TRENDS
MAY BE FOR MORE DRY AND WARM WEATHER ON THURSDAY. IF THAT
HAPPENS...OUR CURRENT HIGHS WILL BE A BIT TOO LOW...EXCEPT FOR
MAYBE THE SOUTHEAST.
ANOTHER WRINKLE IN THE LATEST MODELS IS THAT THE FRONT ONLY SLOWLY
MOVES ACROSS ILLINOIS THUR NIGHT THROUGH FRIDAY NIGHT. THAT SLOWER
SCENARIO WOULD KEEP RAIN IN OUR FORECAST THUR NIGHT THROUGH
SATURDAY MORNING...WHEN THE FRONT FINALLY DEPARTS TO THE SOUTHEAST.
THE ARRIVAL OF COLDER AIR FOR NEXT WEEKEND IS STILL IN
AGREEMENT...WITH THE GFS COLDER THAN THE ECMWF BY 3-4C. BELOW
NORMAL TEMPS LOOK TO BE THE RULE INTO EARLY NEXT WEEK AS HIGH
PRESSURE SETTLES INTO THE MID MISSISSIPPI RIVER VALLEY THROUGH AT
LEAST TUESDAY...KEEPING WARM AIR SHUNTED TO THE WEST OF ILLINOIS.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
810 PM EDT MON OCT 22 2012
.AVIATION... /00 UTC TAFS/
CONTD CONVECTION ALONG TAIL OF SHORTWAVE TROF MOVG EWD THROUGH NRN
INDIANA WITH STRONG PARCEL FORCING PER 40KT 8H JET SAMPLED PER KIWX
VWP. SHORT DURATION /NEXT 2HRS/ TEMPO TSRA AT KFWA TO COVER WITH
FAIRLY STRONG CONFIDENCE OF OCCRNC. BULK OF PRECIP PUSHED WELL N-E
OF KSBN WITH ONLY VCSH MENTION THERE. HAVE SIDED MORE OPTIMISTIC
WITH FCST THIS CYCLE/PRIMARILY VFR MET CONDS...WITH THE ASSUMPTION
THAT WARM SECTOR DOMINANCE WL MAINTAIN ACRS NRN INDIANA. EXCEPTION
TO WHICH /ASIDE FM INITIAL TSRA AT KFWA/ WL BE W/POTNL CONVECTION
ASSOCD WITH SHORTWAVE CRNTLY ACRS ECNTL MO AS IT LIFTS NEWD. TIMING
OF PD SHRA WITH TEMPO FUEL ALT CONDS ERLY TUE AM. AT THIS TIME TSRA
CHCS REMAIN UNCERTAIN/CONDITIONAL AND AWAIT HIR CONFIDENCE BEFORE
MENTION.
&&
.SHORT TERM... /TONIGHT THROUGH TUESDAY NIGHT/
COMPLEX SHORT TERM FORECAST GIVEN PROBLEMATIC MCV ROTATING THROUGH
WESTERN LAKES THIS AFTERNOON. CONVECTION HAS FIRED AHEAD OF MAIN
SHORT WAVE IN AREA OF STRONG THETA E ADVECTION WITH LOW LEVEL JET.
SATELLITE AND RADAR MOSAIC SHOWS MCV DEVELOPED OVER NORTHERN IL AND
LIFTING NORTH INTO WI. 12Z 4KM WRF WAS A TOTAL BUST WITH NO
INDICATION OF THIS LINE OF CONVECTION AT 18Z. HRRR WAS PERFORMING
WELL ON A FEW OF ITS RUNS AND GENERALLY FOLLOWED WITH SOME
EXTRAPOLATION. MOST SPECTRAL GUIDANCE DID NOT MODEL MCV AND
ASSOCIATED SUBSIDENCE IN ITS WAKE WHICH HAS LIMITED ANY FURTHER
DEVELOPMENT. SPECTRAL MODELS SEEM OVER AGGRESSIVE WITH ADDITIONAL
PCPN DEVELOPMENT THIS EVENING INTO EARLY OVERNIGHT HOURS IN AREA
NEAR WARM FRONT BUT BETWEEN SYNOPTIC SHORT WAVES. HAVE TIMED CURRENT
CONVECTION ACROSS CWA INTO EARLY EVENING HOURS WITH A DIMINISHING
TREND. KEPT CHANCE POPS GOING ENTIRE AREA THIS EVENING. SECOND SHORT
WAVE AND PV ANOMALY APPROACH LATE TONIGHT AND THIS FEATURE SLOWER
THAN PREVIOUS RUNS. NOW LOOKS LIKE THIS WILL IMPACT MOST OF AREA ON
TUESDAY. HAVE ADJUSTED TIMING/DETAIL OF POPS WITH LIKELY LATE
TONIGHT AND TUE MORNING ALL BUT SE AREAS. KEPT A CHANCE ACROSS
NORTHEAST TUE AFTERNOON WITH SHORT WAVE OVER THE AREA BUT MOVING
EAST. TEMPS WILL REMAIN WARM THROUGH THE PERIOD WITH LOWS IN UPPER
50S TO LOWER 60S. HIGHS ON TUE AGAIN TRICKY WITH CLOUDS AND PCPN BUT
SINCE WE MANAGED TO REACH 70 MOST AREAS TODAY SEE SIMILAR NUMBERS ON
TUE WITH MID 70S POSSIBLE SOUTH WHERE RAIN ENDS IN MORNING. BLENDED
GUIDANCE LOOKS GOOD.
&&
.LONG TERM... /WEDNESDAY THROUGH MONDAY/
UNSEASONABLY WARM WEATHER WILL BE IN STORE INTO THURSDAY WITH
CONTINUED SOUTHWESTERLY FLOW INTO THE REGION. MODELS IN GOOD
AGREEMENT THROUGH THURSDAY WITH 850 MB TEMPS IN THE +15 TO +17
CELSIUS RANGE. SOUNDINGS WOULD SUGGEST THAT TEMPS WILL ONLY MIX
THROUGH AROUND 900 MB YIELDING HIGHS IN THE MID TO UPPER 70S WEDS
AND THURS AFTERNOON WHICH IS INLINE WITH PREV GRIDS AND NEAR OR
ABOVE GUIDANCE. IF FULL MIX OUT THROUGH 850 MB OCCURS...TEMPS COULD
JUMP INTO THE LOWER 80S.
FORECAST BECOMES MORE MUDDLED THROUGH THE REMAINDER OF THE FORECAST
IN TERMS OF HANDLING OF SEVERAL LARGE SCALE FEATURES. FIRST IS LARGE
TROUGH WHICH WILL BE DIGGING INTO THE PLAINS WITH MAIN UPPER LEVEL
SYSTEM IN CENTRAL CANADA. THIS FEATURE DRIVES A STRONG COLD FRONT
THROUGH THE AREA IN THURS NGT/FRI TIME FRAME. FROM HERE THE MODELS
BEGIN TO DIVERGE ON HANDLING OF PROGRESSIVENESS OF THE TROUGH. 12Z
GFS HAS KEPT A POSITIVELY TILTED SYSTEM SWEEPING THROUGH AND COLDER
AIR ARRIVING BEHIND IT WITH LITTLE LINGERING PRECIP. 00Z ECMWF
STALLED THE FRONT ACROSS THE REGION WITH ADDITIONAL ENERGY MOVING
ALONG IT TO BRING CHANCES INTO SATURDAY. 12Z GEFS/GEM/00Z ECMWF THEN
INDICATE TROUGH BECOMES SOMEWHAT NEGATIVELY TILTED. THIS BRINGS TO
LIGHT THE 2ND FEATURE OF CONCERN...WHAT WILL LIKELY BECOME TROPICAL
SYSTEM SANDY LATER TODAY. MODELS GENERALLY INTENSIFY THE SYSTEM AND
TRACK INTO THE WESTERN ATLANTIC. THIS WILL CAUSE A BLOCKY PATTER TO
ESTABLISH WITH MODELS BOUNCING BACK AND FORTH ON POSSIBLE PHASING OF
SOME OF THE TROPICAL ENERGY AND THE TROUGH...DEVELOPING A LARGE
STORM SYSTEM THAT COULD BRING IN A BLAST OF COLD AIR AND CHANCES FOR
RAIN OR SNOW INTO NEXT WEEK. 12Z ECMWF HAS BACKED OFF ON MORE
WESTWARD SOLUTION OF THIS PHASING AND SOMEWHAT MORE REALISTIC
BOMBING OUT OF THE SYSTEM OFF THE EAST COAST. COLDER AIR WILL STILL
ARRIVE REGARDLESS WITH POTENTIAL FOR LAKE EFFECT POSSIBLY IN PLAY.
HAVE TRIED TO KEEP FOR THE MOST PART WITH PREV GRIDS AND UNDERCUT
GUIDANCE WITH TRENDS OF ALL MODELS STILL SUGGESTING A DROP TO WELL
BELOW NORMAL TEMPS. REMOVED SOME OF THE MIXED PRECIP WORDING WITH
1000-850 MB THICKNESS VALUES GENERALLY IN THE 1300 TO 1310 DM
RANGE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS GOODLAND KS
556 PM MDT MON OCT 22 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 222 PM MDT MON OCT 22 2012
AS OF 2 PM...SKIES ACROSS THE TRI-STATE AREA RANGED FROM CLEAR TO
MOSTLY CLOUDY DUE TO STRATUS THAT DEVELOPED THIS MORNING. TEMPERATURES
WERE IN THE MID TO UPPER 60S IN AREAS WHERE THE CLOUDS HAVE BURNED
OFF AND IN THE UPPER 50S TO LOW 60S WHERE THE CLOUDS HAVE
REMAINED. WINDS WERE BEGINNING TO TURN TO THE SOUTHEAST FROM WEST
TO EAST AS A LOW PRESSURE SYSTEM LOCATED OVER EASTERN KANSAS MOVES AWAY
TO THE NORTHEAST.
TONIGHT...THROUGH MODELS AND LOCAL FORECASTER COLLABORATION...
EXPECTING FOG AND STRATUS TO DEVELOP AGAIN. THE KEY TO THE ENTIRE
SHORT TERM FORECAST DEPENDS ON THE STRATUS AND FOG DEVELOPMENT. AT
THIS TIME...FOG AND STRATUS IS NOT EXPECTED TO FORM AS FAR WEST AS
MONDAY MORNING. LOW TEMPERATURES WILL BE HIGHER TO THE EAST AS A
RESULT OF CLOUD COVER AND HIGHER DEW POINTS AND COOLER TO THE WEST
WITH CLEAR SKIES.
FOR TOMORROW...THE FOG AND STRATUS WILL BEGIN BURNING OFF DURING
THE MID TO LATE MORNING HOURS. DOWNSLOPE SOUTHWEST WINDS WILL
PICK UP AND AND BRING IN SOME DRIER AIR...HELPING TO ERODE THE FOG
AND STRATUS. HIGH TEMPERATURES COULD SOAR TO THE MID TO UPPER 80S
AS A RESULT OF DOWNSLOPE FLOW FROM THE SOUTHWEST AND DRY AIR
MOVING IN. HOWEVER...DUE TO CONCERNS OVER THE COVERAGE AND TIMING
OF THE FOG AND STRATUS...DID NOT FORECAST NEAR RECORD TEMPERATURES
ALTHOUGH IT IS CERTAINLY POSSIBLE TO NEAR RECORD HIGHS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 230 PM MDT MON OCT 22 2012
TUESDAY NIGHT THROUGH WEDNESDAY DRY AIR REMAINS IN PLACE AHEAD OF A
LONG WAVE TROUGH MOVING SOUTH THROUGH THE INTERMOUNTAIN WEST.
WEDNESDAY AHEAD OF THE TROUGH A COLD FRONT WILL MOVE INTO THE
AREA...SLOWLY MOVING SOUTH THROUGH THE DAY. THE FRONT WILL EXIT THE
AREA BY MIDNIGHT. BEHIND THE FRONT 1000-500MB RELATIVE HUMIDITY
INCREASES. DURING THE NIGHT THE LONG WAVE TROUGH MOVES OVER THE
AREA. LIFT INCREASES DURING THE LATE EVENING...PEAKING AROUND
MIDNIGHT THEN TAPERING OFF AS THE MAIN AREA OF LIFT WITHIN THE LONG
WAVE TROUGH EXITS THE AREA BY SUNRISE THURSDAY. PRECIP CHANCES
DURING THE NIGHT FOLLOW THE SAME TREND AS THE LIFT SINCE THERE WILL
BE AMPLE MOISTURE TO WORK WITH THROUGH THE NIGHT. ONE CONCERN IS THE
RIGHT EXIT REGION OF THE 500 AND 300 MB JET WILL BE OVER THE
MAJORITY OF THE AREA WEDNESDAY NIGHT AND THE ENVIRONMENT WILL ONLY BE
SATURATED FROM 850-700MB. GIVEN THESE CONCERNS KEPT PRECIP CHANCES
BELOW 50 PERCENT DESPITE THE PLENTIFUL LIFT IN THE SATURATED
LAYER. ON A SIDE NOTE...AM NOT ANTICIPATING THE RAIN TO CHANGE
PHASE SINCE SOUNDINGS ARE NOT SATURATED ABOVE -10C AND DEW POINTS
AT THE SURFACE REMAIN ABOVE 0C.
FOR THURSDAY THROUGH MONDAY...THE PERIOD WILL START OUT WITH SOME
LINGERING PRECIP CHANCES OVER THE NORTHWEST PART OF THE AREA AS
THE FIRST SHORT WAVE TROUGH DEPARTS THE AREA. THURSDAY NIGHT AND
FRIDAY ANOTHER SHORT WAVE TROUGH WITHIN THE MAIN UPPER LEVEL WAVE
MOVES OVER THE AREA. SNOWFALL CAN BE EXPECTED ACROSS MOST OF THE
AREA THURSDAY NIGHT AND/OR FRIDAY. SNOW AMOUNTS AT THIS TIME LOOK
TO BE FAIRLY MINIMAL. OTHERWISE THE PRECIP CHANCES WILL END BY THE
WEEKEND AS THE SHORT WAVE TROUGH DEPARTS THE AREA FRIDAY NIGHT AND
THE JET STREAM MOVES NORTH OF THE AREA. TEMPERATURES THROUGH THE
PERIOD WILL BE NEAR NORMAL WEDNESDAY WITH BELOW NORMAL VALUES
EXPECTED THROUGH FRIDAY NIGHT. TEMPERATURES FOR THE WEEKEND WILL
WARM AS A WARMER AIR MASS MOVES INTO THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 555 PM MDT MON OCT 22 2012
VFR TO MVFR CONDITIONS ARE EXPECTED OVER THE TAF PERIOD AT BOTH MCK
AND GLD. FOG AND LOW STRATUS ARE EXPECTED TO DEVELOP TONIGHT...WITH
MORE CONFIDENCE IN FOG DEVELOPING AT MCK THAN GLD. AN AREA OF LOW
STRATUS OVER SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS WILL
ADVECT WESTWARD EARLY TONIGHT WHICH GIVES BETTER CONFIDENCE TO MCK.
AT GLD THE WIND DIRECTION WILL PLAY A LARGE PART IN DETERMINING IF
FOG DEVELOPS AND HOW DENSE IT WILL BE. IF WINDS TURN TO THE
SOUTHWEST EARLIER THAN EXPECTED...BRINGING IN DRIER AIR...DENSE FOG
DOES NOT SEEM LIKELY. WHILE THE HRRR IS CONTINUING TO DEVELOP A
THICK LAYER OF FOG AT GLD BY 09Z...THE GFS LAMP GUIDANCE HAS PULLED
BACK ON ITS PREVIOUSLY BULLISH VISIBILITY FORECAST. THE UPS FOG
FORECASTING TECHNIQUE LEADS TO DENSE FOG LIKELY AT BOTH SITES...BUT
AGAIN...THE WIND DIRECTION AND RESULTING LOW LEVEL MOISTURE WILL
DETERMINE IF FOG REACHES GLD LATE TONIGHT INTO EARLY TOMORROW. IT
SHOULD BE NOTED THAT AN ASSUMPTION OF THE UPS TECHNIQUE IS THAT NO
DRY AIR WILL BE ADVECTED...WHICH MAY HAPPEN WITH SOUTH TO
SOUTHWEST WINDS. LOCAL CLIMATOLOGY ALSO DOES NOT SUPPORT FOG OR
LOW STRATUS WHEN WINDS TURN TO THE SOUTHWEST.
ANY FOG AND LOW STRATUS THAT DEVELOPS OVERNIGHT WILL DISSIPATE BY
MID MORNING LEADING TO MOSTLY SUNNY SKIES AND LIGHT WEST-SOUTHWEST
WINDS AT GLD DURING THE DAY ON TUESDAY.
&&
.FIRE WEATHER...
ISSUED AT 222 PM MDT MON OCT 22 2012
FIRE WEATHER CONDITIONS MAY BECOME A CONCERN ON TUESDAY. DOWNSLOPE
WINDS FROM THE SOUTHWEST WILL PICK UP...ESPECIALLY DURING THE
AFTERNOON HOURS. WIND SPEEDS OF 10 TO 20 MPH WITH GUSTS TO 25 IS
FORECAST FOR THE WESTERN HALF OF THE FORECAST AREA. RELATIVE
HUMIDITY VALUES WILL DEPEND HIGHLY UPON FOG AND STRATUS
DEVELOPMENT DURING THE OVERNIGHT HOURS. IF THE FOG AND STRATUS
HANGS ON LONGER LIKE TODAY...RELATIVE HUMIDITY VALUES WILL REMAIN
TOO HIGH FOR DANGEROUS FIRE WEATHER CONDITIONS. AT THIS
TIME...ISSUED A FIRE WEATHER WATCH FOR PORTIONS OF THE AREA DUE TO
UNCERTAINTY OF FOG AND STRATUS DEVELOPMENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH TUESDAY AFTERNOON FOR KSZ001-013-014-027>029-
041-042.
CO...FIRE WEATHER WATCH TUESDAY AFTERNOON FOR COZ252>254.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...JTL
AVIATION...JJM/MENTZER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
240 PM MDT SUN OCT 21 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 116 PM MDT SUN OCT 21 2012
TRICKY FORECAST THROUGH TOMORROW. A LOT OF IT WILL DEPEND ON WHEN
STRATUS FORMS TONIGHT...THE EXTENT OF THE STRATUS AND WHEN IT WILL
BURN OFF TOMORROW. THIS IS COMPOUNDED BY THE FACT THAT THE MODELS
HAVE BEEN HAVING TROUBLE WITH THE TEMPERATURES AND THE WIND/PRESSURE
FIELD. IN GENERAL THE MODELS DO SAY STRATUS WILL FORM BUT DIFFER
ON THE TIMING. FOR THE STRATUS THAT DEVELOPED LAST NIGHT/THIS
MORNING TO THE NORTH AND EAST OF THE AREA...THE RUC FOLLOWED BY
THE GFS DID THE BEST. THE NAM WAS A LITTLE QUICK IN DISSIPATING
THE MOISTURE.
IF GO BY THE RUC...STRATUS DEVELOPS EARLY IN THE EVENING IN THE EAST
WITH THE GFS HOLDING OFF UNTIL NEAR 06Z WITH THE NAM BETWEEN 06Z AND
09Z. AM LEANING TOWARD THE EARLIER DEVELOPMENT WITH ANY FOG TO THE
EAST OF THE AREA. THAT AND HOW STRONG THE WINDS WILL BE WILL DETERMINE
THE MINS. MODELS HAVE BEEN ALL OVER THE PLACE AND WRONG THE LAST COUPLE
OF NIGHTS. AT THIS TIME WILL GO NEAR TO SLIGHTLY BELOW GUIDANCE. HOW
FAST THE STRATUS BURNS OFF WILL BE THE BIG FACTOR ON MAXES MONDAY. THE
WIND FIELD ENDS UP LIGHT AND VARIABLE OR LIGHT UPSLOPE. BELIEVE THE
MODELS ARE TOO FAST IN SCOURING OUT THE MOISTURE WITH NO STRONG
SUBSIDENCE AND DOWNSLOPE COMPONENT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 230 PM MDT SUN OCT 21 2012
FOR MONDAY NIGHT THROUGH TUESDAY NIGHT...THE CLOSED LOW OFF THE COAST
OF THE PACIFIC NORTHWEST WILL MOVE ONSHORE MONDAY NIGHT. THE CLOSED
LOW FILLS AS ANOTHER DEVELOPS BY TUESDAY NIGHT ALONG THE US/CANADIAN
BORDER WHILE A LONG WAVE TROUGH DIVES SOUTH ACROSS THE INTERMOUNTAIN
WEST. AHEAD OF THE LONG WAVE TROUGH THE UPPER LEVEL FLOW WILL
REMAIN FROM THE SOUTHWEST...WITH NUMEROUS SHORT WAVE TROUGHS MOVING
OVER THE AREA. HOWEVER DUE TO A DRY AIR MASS IN PLACE WILL KEEP THE
FORECAST DRY.
AT THE SURFACE A TROUGH WILL MOVE THROUGH THE AREA LATE MONDAY NIGHT
THROUGH TUESDAY MORNING...BRINGING DRIER AIR IN BEHIND IT. AS THE
TROUGH MOVES THROUGH THE EASTERN PART OF THE AREA...LIGHT WINDS AND
LOW DEW POINT DEPRESSIONS MAY ALLOW FOG TO DEVELOP FROM MCCOOK
SOUTHEAST TO HILL CITY. THE DRIER AIR AND BREEZY SOUTH WINDS WILL
ALLOW TEMPERATURES TO NEAR RECORD VALUES FOR SOME LOCATIONS TUESDAY. IN
ADDITION...WIND GUSTS NEAR 30 MPH MAY LEAD TO HAZARDOUS FIRE
WEATHER CONDITIONS. SEE FIRE WEATHER SECTION BELOW. LATE TUESDAY
NIGHT A COLD FRONT WILL APPROACH THE AREA...BRINGING AN END TO THE
ABOVE NORMAL TEMPERATURES FOR THE LATTER HALF OF THE WEEK.
FOR THE WEDNESDAY THROUGH SUNDAY PERIOD...THE LONG WAVE TROUGH MOVES
THROUGH THE PLAINS WEDNESDAY NIGHT. WITHIN THIS FEATURE A SHORT
TROUGH AND THE LEFT EXIT OF THE 500MB JET MOVE OVER THE AREA
WEDNESDAY NIGHT...BEHIND A COLD FRONT AT THE SURFACE. PRECIP
CHANCES WILL LINGER INTO THURSDAY AS THE SHORT WAVE TROUGH AND JET
MOVE EAST OF THE AREA. THURSDAY NIGHT ANOTHER SHORT WAVE TROUGH
MOVES ACROSS THE AREA BRINGING ANOTHER ROUND OF PRECIP CHANCES.
AGAIN THE CHANCES LINGER INTO THE FOLLOWING DAY AS THE SHORT WAVE
TROUGH DRIFTS ACROSS THE AREA. SOUNDINGS SHOW THE TEMPERATURE
PROFILE NEARING THE 0C LINE OVERNIGHT THURSDAY THROUGH FRIDAY
MORNING...BUT DISAGREE WITH THE PLACEMENT OF THE RAIN AND SNOW. AT
THIS POINT WILL ONLY PLACE A RAIN/SHOW MIX IN THE FORECAST AND WAIT
UNTIL THIS SYSTEM IS IN THE NEARER TERM BEFORE DETERMINING THE
PLACEMENT OF THE RAIN/SNOW. TEMPERATURES WILL START OUT NEAR/ABOVE
NORMAL WEDNESDAY AS THE COLD FRONT MOVES THROUGH DURING THE
AFTERNOON...THEN COOL TO WELL BELOW NORMAL BY THE END OF THE WEEK.
TEMPERATURES RECOVER SOME DURING THE WEEKEND AS A WARMER AIR MASS
MOVES INTO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1144 AM MDT SUN OCT 21 2012
FORECAST PROBLEMS WILL BE WHERE AND WHEN STRATUS DEVELOPS TONIGHT.
MODELS SHOW IT THEY DIFFER ON HOW FAST TO DO IT. AM THINKING
EARLIER RATHER LATER WHICH FAVORS THE RUC...WHICH WAS HANDLING THE
CURRENT WIND/STRATUS WELL RIGHT NOW...AND THE GFS. FOR KMCK CHOSE
TO ONLY INTRODUCE A SCT LOW DECK BEGINNING AT 02Z AND BRING IN THE
MVFR CEILINGS AT 07Z. HOWEVER THAT COULD BE TOO LATE AND BROUGHT
IN A LITTLE BEFORE 06Z. FOR KGLD IT DOES LOOK A LITTLE LATER. IFR
CEILINGS LOOK TO DEVELOP NEAR 09Z AND CONTINUE THROUGH MID MORNING.
&&
.FIRE WEATHER...
ISSUED AT 230 PM MDT SUN OCT 21 2012
TUESDAY AFTERNOON RELATIVE HUMIDITIES WILL DROP TO AROUND 15 PERCENT
AND WIND GUSTS WILL NEAR 30 MPH FOR LOCATIONS WEST OF A TRENTON
NEBRASKA TO COLBY AND RUSSELL SPRINGS LINE. CURRENTLY THE WINDOW OF
OPPORTUNITY FOR WINDS AND RELATIVE HUMIDITIES TO MEET CRITERIA ARE
TOO SHORT TO WARRENT A FIRE WEATHER HIGHLIGHT. HOWEVER THERE WILL
BE A BRIEF PERIOD DURING THE AFTERNOON THAT CONDITIONS WILL CRITERIA.
&&
.CLIMATE...
ISSUED AT 230 PM MDT SUN OCT 21 2012
HERE ARE THE CURRENT HIGH TEMPERATURE RECORDS FOR LOCATIONS
THAT WILL NEAR THEM ON TUESDAY.
LOCATION RECORD YEAR SET/TIED
GOODLAND 88 2003
HILL CITY 86 1975
BURLINGTON 87 2003
TRIBUNE 88
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
FIRE WEATHER...JTL
CLIMATE...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
136 PM MDT SUN OCT 21 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 116 PM MDT SUN OCT 21 2012
TRICKY FORECAST THROUGH TOMORROW. A LOT OF IT WILL DEPEND ON WHEN
STRATUS FORMS TONIGHT...THE EXTENT OF THE STRATUS AND WHEN IT WILL
BURN OFF TOMORROW. THIS IS COMPOUNDED BY THE FACT THAT THE MODELS
HAVE BEEN HAVING TROUBLE WITH THE TEMPERATURES AND THE WIND/PRESSURE
FIELD. IN GENERAL THE MODELS DO SAY STRATUS WILL FORM BUT DIFFER
ON THE TIMING. FOR THE STRATUS THAT DEVELOPED LAST NIGHT/THIS
MORNING TO THE NORTH AND EAST OF THE AREA...THE RUC FOLLOWED BY
THE GFS DID THE BEST. THE NAM WAS A LITTLE QUICK IN DISSIPATING
THE MOISTURE.
IF GO BY THE RUC...STRATUS DEVELOPS EARLY IN THE EVENING IN THE EAST
WITH THE GFS HOLDING OFF UNTIL NEAR 06Z WITH THE NAM BETWEEN 06Z AND
09Z. AM LEANING TOWARD THE EARLIER DEVELOPMENT WITH ANY FOG TO THE
EAST OF THE AREA. THAT AND HOW STRONG THE WINDS WILL BE WILL DETERMINE
THE MINS. MODELS HAVE BEEN ALL OVER THE PLACE AND WRONG THE LAST COUPLE
OF NIGHTS. AT THIS TIME WILL GO NEAR TO SLIGHTLY BELOW GUIDANCE. HOW
FAST THE STRATUS BURNS OFF WILL BE THE BIG FACTOR ON MAXES MONDAY. THE
WIND FIELD ENDS UP LIGHT AND VARIABLE OR LIGHT UPSLOPE. BELIEVE THE
MODELS ARE TOO FAST IN SCOURING OUT THE MOISTURE WITH NO STRONG
SUBSIDENCE AND DOWNSLOPE COMPONENT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 253 AM MDT SUN OCT 21 2012
THE GFS/EC AND TO A LESSER EXTENT GEM ARE STARTING TO COME MORE IN
LINE WITH ONE ANOTHER ON THE EVOLUTION OF THE NEXT MAJOR SYSTEM TO
AFFECT THE CENTRAL HIGH PLAINS. CURRENT REGIME OF SOUTHWEST FLOW
ALOFT WILL GRADUALLY TRANSITION TO A BROAD TROUGH WED-SAT. SEVERAL
SHORT WAVES ARE FORECAST TO MOVE THROUGH THE TROUGH...ONE WED-WED
NIGHT AND ANOTHER THU NIGHT-FRI NIGHT. AT THE SURFACE...A COLD FRONT
WILL MOVE THROUGH THE AREA WEDNESDAY USHERING IN THE FIRST OF
SEVERAL SURGES OF CANADIAN AIR. GFS/EC/GEM ALL SHOW 850 MB TEMPS
DROPPING BELOW 0C BY FRIDAY MORNING.
GFS CONTINUES TO HAVE A WETTER SOLUTION DURING THIS PERIOD IN
CONTRAST TO THE EC. AFTER COLLABORATION...CURRENT FCST IS LEANING
TOWARD THE DRIER EC SOLUTION. GIVEN FORECAST TEMPS FOR FRIDAY HAVE
MENTIONED A LIGHT RAIN-SNOW MIX FOR PRECIP TYPE...COULD END UP BEING
ALL LIGHT SNOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1144 AM MDT SUN OCT 21 2012
FORECAST PROBLEMS WILL BE WHERE AND WHEN STRATUS DEVELOPS TONIGHT.
MODELS SHOW IT THEY DIFFER ON HOW FAST TO DO IT. AM THINKING
EARLIER RATHER LATER WHICH FAVORS THE RUC...WHICH WAS HANDLING THE
CURRENT WIND/STRATUS WELL RIGHT NOW...AND THE GFS. FOR KMCK CHOSE
TO ONLY INTRODUCE A SCT LOW DECK BEGINNING AT 02Z AND BRING IN THE
MVFR CEILINGS AT 07Z. HOWEVER THAT COULD BE TOO LATE AND BROUGHT
IN A LITTLE BEFORE 06Z. FOR KGLD IT DOES LOOK A LITTLE LATER. IFR
CEILINGS LOOK TO DEVELOP NEAR 09Z AND CONTINUE THROUGH MID MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1239 PM CDT SUN OCT 21 2012
...UPDATED FOR THE SYNOPSIS...
.SYNOPSIS...
ISSUED AT 1237 PM CDT SUN OCT 21 2012
THE 250MB UPPER LEVEL ANALYSIS FROM 21/12Z SHOWED A WEST TO EAST
JET FROM THE COAST OF OREGON EAST THROUGH MONTANA AND THEN CURVING
SOUTHEAST TO WESTERN KENTUCKY. JETLET SPEEDS WERE IN THE 130-140KT
RANGE ACROSS IDAHO AND SOUTHWESTERN MONTANA, AND IN THE 110KT
RANGE OVER INDIANA AND WESTERN OHIO. ANOTHER SOUTHERLY JET IN THE
100 TO 120 KNOT RANGE WAS JUST OFF THE NEW ENGLAND COAST NORTHWARD
INTO TO NOVA SCOTIA, CANADA. THE 500MB ANALYSIS SHOWED BROAD
RIDGING OVER THE SOUTHERN PLAINS AND MIDWESTERN STATES, WITH AN
OPEN WAVE DOWN SOUTHWESTWARD OFF THE BAJA COAST. A LARGE LOW
PRESSURE CENTER OVER EASTERN ONTARIO HAD A TRAILING TROUGH
SOUTHWARD THROUGH PENNSYLVANIA AND NEW YORK EXTENDING TO OFF THE
EASTERN COAST OF SOUTH CAROLINA. ANOTHER LARGE SCALE LOW PRESSURE
AREA WAS OVER WESTERN CANADA. THE 700MB PRESSURE PATTERN WAS VERY
SIMILAR TO THE 500MB LEVEL, BUT WITH A WEAK TROUGH OVER THE
COLORADO AND NEBRASKA BORDER. THE TEMPERATURE AND WINDS AT DDC AT
H7 WERE +12C AND 18015KT. THE 850MB ANALYSIS SHOWED A COLD FRONT
FROM EASTERN SOUTH DAKOTA TO EXTREME NORTHWEST KANSAS TO NORTHERN
UTAH. A GOOD SWATH OF 850MB MOISTURE WAS FLOWING NORTH INTO
CENTRAL AND EASTERN KANSAS THIS MORNING. DDC`S 850MB TEMP WAS +21C
AND THE WINDS WERE 19015KT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 115 AM CDT SUN OCT 21 2012
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS NEAR 20 DEGREES
ABOVE NORMAL.
THE SUBTROPICAL 500 HPA LOW MENTIONED IN THE SYNOPSIS WILL BECOME ABSORBED
IN THE SW FLOW ALOFT ACROSS THE DESERT SOUTHWEST TODAY. THIS FEATURE
WILL NOT MOVE ACROSS KANSAS UNTIL THE OVERNIGHT HOURS. THIS UL FEATURE
WILL EVENTUALLY MOVE A COLD FRONT ACROSS THE REGION. THIS FRONT
WILL NOT MOVE MUCH TODAY AND SW KANSAS WILL REMAIN IN THE WARM SECTOR.
850 HPA TEMPERATURES ACROSS SOUTH CENTRAL KANSAS LOOK TO BE VERY WARM
FOR OCTOBER (IN THE LOWER 20 DEG C). THIS COULD EASILY SUPPORT TEMPERATURES
AROUND 90 DEG F ACROSS SOUTH CENTRAL KANSAS. SURFACE DEWPOINTS WILL
ALSO INCREASE TODAY AND THE HRRR SHOWS SOME PATCHY FOG ACROSS SOUTH
CENTRAL KANSAS THIS MORNING. WINDS IN THE WAKE OF THE FROPA ARE NOT
EXPECTED TO BE STRONG DUE TO THE DEAMPLIFICATION OF THE SYNOPTIC WAVE
WITH TIME AND LACK OF STRONG HEIGHT FALLS ALOFT. AN INCREASE IN MID
TO HIGH LEVEL CLOUDS IS EXPECTED TONIGHT AND INTO TOMORROW MORNING.
OVERNIGHT LOWS INTO MONDAY MORNING ARE EXPECTED TO BE IN THE 40S DEG
F ACROSS WEST CENTRAL KANSAS TO 50S DEG F ACROSS SOUTH CENTRAL KANSAS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 405 AM CDT SUN OCT 21 2012
ON MONDAY AN UPPER LEVEL SUBTROPICAL SHORTWAVE TROUGH MOVES RAPIDLY
NORTHEASTWARD FROM NEW MEXICO ACROSS THE CENTRAL AND SOUTHERN
PLAINS. LAYER MOISTURE IS LIMITED WITH THIS SYSTEM SO WILL CONTINUE
WITH A DRY FORECAST. LIGHT NORTH WINDS BECOME LIGHT SOUTHEASTERLY
BEHIND A COLD FRONT WITH THE FRONTAL BOUNDARY STALLING OUT JUST
SOUTH OF THE OKLAHOMA BORDER. HIGH TEMPS WILL BE THE COOLEST IN THE
NORTH FROM SCOTT CITY TO HAYS IN THE MID 70S AND WARMER SOUTH FROM
THE UPPER 70S TO LOWER 80S.
FOR MONDAY NIGHT A WARM FRONT MOVES BACK NORTH FROM OKLAHOMA ACROSS
WESTERN KANSAS WITH LIGHT SOUTHEAST WINDS BECOMING SOUTH. 850MB
TEMPS RISE TO 22 TO 24C. THERE COULD BE SOME STRATUS IN THE EAST FA
FROM SAINT JOHN TO PRATT AS HIGHER DEWPOINTS RETURN. OVERNIGHT LOWS
ARE FORECAST TO BE MILD AND RANGE FROM THE UPPER 40S WEST TOWARDS
THE COLORADO BORDER TO AROUND 60 EAST FROM SAINT JOHN TO MEDICINE
LODGE.
FOR TUESDAY AND WEDNESDAY A STRONG UPPER LEVEL SHORTWAVE TROUGH
MOVES FROM THE WESTERN CONUS AND INTO THE 4 CORNERS REGION AND
ROCKIES. AHEAD OF THIS SYSTEM, WESTERN KANSAS WILL BE IN THE WARM
SECTOR WITH HIGHS IN THE MID TO UPPER 80S. THE SURFACE PRESSURE
GRADIENT TIGHTENS ACROSS WESTERN KANSAS ON WEDNESDAY AFTERNOON AS
PRESSURES FALL IN THE LEE OF THE ROCKIES. A DRYLINE WILL SET UP IN
THE AFTERNOON ACROSS CENTRAL KANSAS WITH VERY DRY SURFACE AIR IN THE
WEST. IF WINDS MIX DEEPLY ENOUGH IN THE WEST COULD BE CLOSE TO
CRITICAL FIRE WEATHER CONDITIONS. OVERNIGHT LOWS ARE FORECAST TO BE
MILD AND IN THE 50S.
ON THURSDAY THE UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE PLAINS
PUSHING A STRONG COLD FRONT ACROSS KANSAS. WILL KEEP A SMALL POP
GOING FOR A FEW THUNDERSTORMS FROM NEAR HAYS TO COLDWATER AND EAST
FOR WEDNESDAY NIGHT AND THURSDAY MORNING, HOWEVER CONFIDENCE IS LOW
WITH AN UPPER LEVEL DRY SLOT INTRUSION. THE BETTER CHANCE FOR
THUNDERSTORMS LOOKS EAST INTO CENTRAL KANSAS WITH THE DEEPER
MOISTURE. HIGHS ON THURSDAY BEHIND THE COLD FRONT ARE FORECAST TO BE
ONLY IN THE 60S.
FOR FRIDAY A SECONDARY UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE
PLAINS RE-ESTABLISHING THE COLDER AIRMASS. A FEW RAIN SHOWERS MAY
DEVELOP IN THE COLDER AIR IN THE EAST FA AROUND MEDICINE LODGE AND
WILL COVER WITH A LOW POP. THE GFS AND CANADIAN MODELS LOOK TO
DEEP WITH THE TROUGH AXIS THAN THE NEW ECMWF AND HAS MUCH MORE
PRECIPITATION BREAKING OUT. FOR NOW WILL SIDE WITH THE DRIER
ECMWF. HIGHS ON FRIDAY LOOK TO BE ONLY IN THE MID TO UPPER 5OS.
OVERNIGHT LOWS ON FRIDAY MORNING LOOK TO BE IN UPPER 30S TO MID
40S.
FOR NEXT WEEKEND DRY NORTHWESTERLY FLOW CONTINUES BEHIND THE UPPER
LEVEL TROUGH WITH A COLD AIRMASS IN PLACE AND HIGHS ONLY IN THE 40S
TO LOWER 50S. OVERNIGHT LOWS COULD GET DOWN BELOW THE FREEZING MARK
DEPENDING ON WHERE THE SURFACE RIDGE SETS UP AND WHERE WINDS CAN GO
LIGHT FOR BOTH SATURDAY AND SUNDAY MORNINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1201 PM CDT SUN OCT 21 2012
THIS AFTERNOON WILL START WITH WEAK HIGH PRESSURE CENTERED
SOUTHWEST OF KANSAS, AND A COLD FRONT MOVING SOUTH THROUGH
NEBRASKA. A FEW CLOUDS WILL BE BKN OVER THE HYS TAF SITE THROUGH
MID AFTERNOON, IN THE 18,000 FT RANGE. THOSE CLOUDS WILL
DISSIPATE BY 20Z, AND A SOUTHWEST FLOW OF 08G16KT WILL BECOME
ESTABLISHED ACROSS ALL THREE TAF SITES, ALONG WITH MOSTLY CLEAR
SKIES. THE APPROACHING FRONT WILL BRING A WIND SHIFT TO THE NORTH
TO NORTHWEST TONIGHT, SHIFTING AT HYS AROUND 06Z, AT GCK AROUND
07Z AND AT DDC BY 09Z. WINDS BEHIND THE FRONT WILL BE 34010-12KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 46 78 53 / 0 0 0 0
GCK 86 43 76 48 / 0 0 0 0
EHA 87 47 80 50 / 0 0 0 0
LBL 88 46 80 47 / 0 0 0 0
HYS 84 47 75 51 / 0 0 10 0
P28 90 54 83 59 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURKE
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1201 PM CDT SUN OCT 21 2012
...UPDATED FOR THE 18Z TAF AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1100 PM CDT SAT OCT 20 2012
THE 21.00Z 250 HPA RAOB MAP SHOWED A STRONG 130 KT WESTERLY JET LOCATED
ACROSS SW OREGON. THIS JET WEAKENED SOMEWHAT ACROSS THE NORTHERN ROCKIES
AND THEN INCREASED TO AROUND 125 KT ACROSS THE NORTHERN PLAINS. AT 500
HPA, A SUBTROPICAL LOW WAS LOCATED SW OF CALIFORNIA. A BROAD TROF EXTENDED
ACROSS THE PACIFIC NORTHWEST. AT 700 AND 850 HPA, A WARM PLUME PREVAILED
ACROSS THE PLAINS. AT THE SFC, A FRONTAL SYSTEM WAS LOCATED ACROSS THE
WEST COAST. ANOTHER FRONTAL SYSTEM WAS LOCATED ACROSS THE CENTRAL CANADIAN
PRAIRIE PROVINCES INTO THE PLAINS. YET ANOTHER FRONTAL SYSTEM WAS LOCATED
OFFSHORE OF THE EAST COAST.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 115 AM CDT SUN OCT 21 2012
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS NEAR 20 DEGREES
ABOVE NORMAL.
THE SUBTROPICAL 500 HPA LOW MENTIONED IN THE SYNOPSIS WILL BECOME ABSORBED
IN THE SW FLOW ALOFT ACROSS THE DESERT SOUTHWEST TODAY. THIS FEATURE
WILL NOT MOVE ACROSS KANSAS UNTIL THE OVERNIGHT HOURS. THIS UL FEATURE
WILL EVENTUALLY MOVE A COLD FRONT ACROSS THE REGION. THIS FRONT
WILL NOT MOVE MUCH TODAY AND SW KANSAS WILL REMAIN IN THE WARM SECTOR.
850 HPA TEMPERATURES ACROSS SOUTH CENTRAL KANSAS LOOK TO BE VERY WARM
FOR OCTOBER (IN THE LOWER 20 DEG C). THIS COULD EASILY SUPPORT TEMPERATURES
AROUND 90 DEG F ACROSS SOUTH CENTRAL KANSAS. SURFACE DEWPOINTS WILL
ALSO INCREASE TODAY AND THE HRRR SHOWS SOME PATCHY FOG ACROSS SOUTH
CENTRAL KANSAS THIS MORNING. WINDS IN THE WAKE OF THE FROPA ARE NOT
EXPECTED TO BE STRONG DUE TO THE DEAMPLIFICATION OF THE SYNOPTIC WAVE
WITH TIME AND LACK OF STRONG HEIGHT FALLS ALOFT. AN INCREASE IN MID
TO HIGH LEVEL CLOUDS IS EXPECTED TONIGHT AND INTO TOMORROW MORNING.
OVERNIGHT LOWS INTO MONDAY MORNING ARE EXPECTED TO BE IN THE 40S DEG
F ACROSS WEST CENTRAL KANSAS TO 50S DEG F ACROSS SOUTH CENTRAL KANSAS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 405 AM CDT SUN OCT 21 2012
ON MONDAY AN UPPER LEVEL SUBTROPICAL SHORTWAVE TROUGH MOVES RAPIDLY
NORTHEASTWARD FROM NEW MEXICO ACROSS THE CENTRAL AND SOUTHERN
PLAINS. LAYER MOISTURE IS LIMITED WITH THIS SYSTEM SO WILL CONTINUE
WITH A DRY FORECAST. LIGHT NORTH WINDS BECOME LIGHT SOUTHEASTERLY
BEHIND A COLD FRONT WITH THE FRONTAL BOUNDARY STALLING OUT JUST
SOUTH OF THE OKLAHOMA BORDER. HIGH TEMPS WILL BE THE COOLEST IN THE
NORTH FROM SCOTT CITY TO HAYS IN THE MID 70S AND WARMER SOUTH FROM
THE UPPER 70S TO LOWER 80S.
FOR MONDAY NIGHT A WARM FRONT MOVES BACK NORTH FROM OKLAHOMA ACROSS
WESTERN KANSAS WITH LIGHT SOUTHEAST WINDS BECOMING SOUTH. 850MB
TEMPS RISE TO 22 TO 24C. THERE COULD BE SOME STRATUS IN THE EAST FA
FROM SAINT JOHN TO PRATT AS HIGHER DEWPOINTS RETURN. OVERNIGHT LOWS
ARE FORECAST TO BE MILD AND RANGE FROM THE UPPER 40S WEST TOWARDS
THE COLORADO BORDER TO AROUND 60 EAST FROM SAINT JOHN TO MEDICINE
LODGE.
FOR TUESDAY AND WEDNESDAY A STRONG UPPER LEVEL SHORTWAVE TROUGH
MOVES FROM THE WESTERN CONUS AND INTO THE 4 CORNERS REGION AND
ROCKIES. AHEAD OF THIS SYSTEM, WESTERN KANSAS WILL BE IN THE WARM
SECTOR WITH HIGHS IN THE MID TO UPPER 80S. THE SURFACE PRESSURE
GRADIENT TIGHTENS ACROSS WESTERN KANSAS ON WEDNESDAY AFTERNOON AS
PRESSURES FALL IN THE LEE OF THE ROCKIES. A DRYLINE WILL SET UP IN
THE AFTERNOON ACROSS CENTRAL KANSAS WITH VERY DRY SURFACE AIR IN THE
WEST. IF WINDS MIX DEEPLY ENOUGH IN THE WEST COULD BE CLOSE TO
CRITICAL FIRE WEATHER CONDITIONS. OVERNIGHT LOWS ARE FORECAST TO BE
MILD AND IN THE 50S.
ON THURSDAY THE UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE PLAINS
PUSHING A STRONG COLD FRONT ACROSS KANSAS. WILL KEEP A SMALL POP
GOING FOR A FEW THUNDERSTORMS FROM NEAR HAYS TO COLDWATER AND EAST
FOR WEDNESDAY NIGHT AND THURSDAY MORNING, HOWEVER CONFIDENCE IS LOW
WITH AN UPPER LEVEL DRY SLOT INTRUSION. THE BETTER CHANCE FOR
THUNDERSTORMS LOOKS EAST INTO CENTRAL KANSAS WITH THE DEEPER
MOISTURE. HIGHS ON THURSDAY BEHIND THE COLD FRONT ARE FORECAST TO BE
ONLY IN THE 60S.
FOR FRIDAY A SECONDARY UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE
PLAINS RE-ESTABLISHING THE COLDER AIRMASS. A FEW RAIN SHOWERS MAY
DEVELOP IN THE COLDER AIR IN THE EAST FA AROUND MEDICINE LODGE AND
WILL COVER WITH A LOW POP. THE GFS AND CANADIAN MODELS LOOK TO
DEEP WITH THE TROUGH AXIS THAN THE NEW ECMWF AND HAS MUCH MORE
PRECIPITATION BREAKING OUT. FOR NOW WILL SIDE WITH THE DRIER
ECMWF. HIGHS ON FRIDAY LOOK TO BE ONLY IN THE MID TO UPPER 5OS.
OVERNIGHT LOWS ON FRIDAY MORNING LOOK TO BE IN UPPER 30S TO MID
40S.
FOR NEXT WEEKEND DRY NORTHWESTERLY FLOW CONTINUES BEHIND THE UPPER
LEVEL TROUGH WITH A COLD AIRMASS IN PLACE AND HIGHS ONLY IN THE 40S
TO LOWER 50S. OVERNIGHT LOWS COULD GET DOWN BELOW THE FREEZING MARK
DEPENDING ON WHERE THE SURFACE RIDGE SETS UP AND WHERE WINDS CAN GO
LIGHT FOR BOTH SATURDAY AND SUNDAY MORNINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1201 PM CDT SUN OCT 21 2012
THIS AFTERNOON WILL START WITH WEAK HIGH PRESSURE CENTERED
SOUTHWEST OF KANSAS, AND A COLD FRONT MOVING SOUTH THROUGH
NEBRASKA. A FEW CLOUDS WILL BE BKN OVER THE HYS TAF SITE THROUGH
MID AFTERNOON, IN THE 18,000 FT RANGE. THOSE CLOUDS WILL
DISSIPATE BY 20Z, AND A SOUTHWEST FLOW OF 08G16KT WILL BECOME
ESTABLISHED ACROSS ALL THREE TAF SITES, ALONG WITH MOSTLY CLEAR
SKIES. THE APPROACHING FRONT WILL BRING A WIND SHIFT TO THE NORTH
TO NORTHWEST TONIGHT, SHIFTING AT HYS AROUND 06Z, AT GCK AROUND
07Z AND AT DDC BY 09Z. WINDS BEHIND THE FRONT WILL BE 34010-12KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 47 78 53 / 0 0 0 0
GCK 86 44 76 48 / 0 0 0 0
EHA 87 47 80 50 / 0 0 0 0
LBL 88 47 80 47 / 0 0 0 0
HYS 84 48 75 51 / 0 0 10 0
P28 90 55 83 59 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...BURKE
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
609 AM CDT SUN OCT 21 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 1100 PM CDT SAT OCT 20 2012
THE 21.00Z 250 HPA RAOB MAP SHOWED A STRONG 130 KT WESTERLY JET LOCATED
ACROSS SW OREGON. THIS JET WEAKENED SOMEWHAT ACROSS THE NORTHERN ROCKIES
AND THEN INCREASED TO AROUND 125 KT ACROSS THE NORTHERN PLAINS. AT 500
HPA, A SUBTROPICAL LOW WAS LOCATED SW OF CALIFORNIA. A BROAD TROF EXTENDED
ACROSS THE PACIFIC NORTHWEST. AT 700 AND 850 HPA, A WARM PLUME PREVAILED
ACROSS THE PLAINS. AT THE SFC, A FRONTAL SYSTEM WAS LOCATED ACROSS THE
WEST COAST. ANOTHER FRONTAL SYSTEM WAS LOCATED ACROSS THE CENTRAL CANADIAN
PRAIRIE PROVINCES INTO THE PLAINS. YET ANOTHER FRONTAL SYSTEM WAS LOCATED
OFFSHORE OF THE EAST COAST.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 115 AM CDT SUN OCT 21 2012
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS NEAR 20 DEGREES
ABOVE NORMAL.
THE SUBTROPICAL 500 HPA LOW MENTIONED IN THE SYNOPSIS WILL BECOME ABSORBED
IN THE SW FLOW ALOFT ACROSS THE DESERT SOUTHWEST TODAY. THIS FEATURE
WILL NOT MOVE ACROSS KANSAS UNTIL THE OVERNIGHT HOURS. THIS UL FEATURE
WILL EVENTUALLY MOVE A COLD FRONT ACROSS THE REGION. THIS FRONT
WILL NOT MOVE MUCH TODAY AND SW KANSAS WILL REMAIN IN THE WARM SECTOR.
850 HPA TEMPERATURES ACROSS SOUTH CENTRAL KANSAS LOOK TO BE VERY WARM
FOR OCTOBER (IN THE LOWER 20 DEG C). THIS COULD EASILY SUPPORT TEMPERATURES
AROUND 90 DEG F ACROSS SOUTH CENTRAL KANSAS. SURFACE DEWPOINTS WILL
ALSO INCREASE TODAY AND THE HRRR SHOWS SOME PATCHY FOG ACROSS SOUTH
CENTRAL KANSAS THIS MORNING. WINDS IN THE WAKE OF THE FROPA ARE NOT
EXPECTED TO BE STRONG DUE TO THE DEAMPLIFICATION OF THE SYNOPTIC WAVE
WITH TIME AND LACK OF STRONG HEIGHT FALLS ALOFT. AN INCREASE IN MID
TO HIGH LEVEL CLOUDS IS EXPECTED TONIGHT AND INTO TOMORROW MORNING.
OVERNIGHT LOWS INTO MONDAY MORNING ARE EXPECTED TO BE IN THE 40S DEG
F ACROSS WEST CENTRAL KANSAS TO 50S DEG F ACROSS SOUTH CENTRAL KANSAS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 405 AM CDT SUN OCT 21 2012
ON MONDAY AN UPPER LEVEL SUBTROPICAL SHORTWAVE TROUGH MOVES RAPIDLY
NORTHEASTWARD FROM NEW MEXICO ACROSS THE CENTRAL AND SOUTHERN
PLAINS. LAYER MOISTURE IS LIMITED WITH THIS SYSTEM SO WILL CONTINUE
WITH A DRY FORECAST. LIGHT NORTH WINDS BECOME LIGHT SOUTHEASTERLY
BEHIND A COLD FRONT WITH THE FRONTAL BOUNDARY STALLING OUT JUST
SOUTH OF THE OKLAHOMA BORDER. HIGH TEMPS WILL BE THE COOLEST IN THE
NORTH FROM SCOTT CITY TO HAYS IN THE MID 70S AND WARMER SOUTH FROM
THE UPPER 70S TO LOWER 80S.
FOR MONDAY NIGHT A WARM FRONT MOVES BACK NORTH FROM OKLAHOMA ACROSS
WESTERN KANSAS WITH LIGHT SOUTHEAST WINDS BECOMING SOUTH. 850MB
TEMPS RISE TO 22 TO 24C. THERE COULD BE SOME STRATUS IN THE EAST FA
FROM SAINT JOHN TO PRATT AS HIGHER DEWPOINTS RETURN. OVERNIGHT LOWS
ARE FORECAST TO BE MILD AND RANGE FROM THE UPPER 40S WEST TOWARDS
THE COLORADO BORDER TO AROUND 60 EAST FROM SAINT JOHN TO MEDICINE
LODGE.
FOR TUESDAY AND WEDNESDAY A STRONG UPPER LEVEL SHORTWAVE TROUGH
MOVES FROM THE WESTERN CONUS AND INTO THE 4 CORNERS REGION AND
ROCKIES. AHEAD OF THIS SYSTEM, WESTERN KANSAS WILL BE IN THE WARM
SECTOR WITH HIGHS IN THE MID TO UPPER 80S. THE SURFACE PRESSURE
GRADIENT TIGHTENS ACROSS WESTERN KANSAS ON WEDNESDAY AFTERNOON AS
PRESSURES FALL IN THE LEE OF THE ROCKIES. A DRYLINE WILL SET UP IN
THE AFTERNOON ACROSS CENTRAL KANSAS WITH VERY DRY SURFACE AIR IN THE
WEST. IF WINDS MIX DEEPLY ENOUGH IN THE WEST COULD BE CLOSE TO
CRITICAL FIRE WEATHER CONDITIONS. OVERNIGHT LOWS ARE FORECAST TO BE
MILD AND IN THE 50S.
ON THURSDAY THE UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE PLAINS
PUSHING A STRONG COLD FRONT ACROSS KANSAS. WILL KEEP A SMALL POP
GOING FOR A FEW THUNDERSTORMS FROM NEAR HAYS TO COLDWATER AND EAST
FOR WEDNESDAY NIGHT AND THURSDAY MORNING, HOWEVER CONFIDENCE IS LOW
WITH AN UPPER LEVEL DRY SLOT INTRUSION. THE BETTER CHANCE FOR
THUNDERSTORMS LOOKS EAST INTO CENTRAL KANSAS WITH THE DEEPER
MOISTURE. HIGHS ON THURSDAY BEHIND THE COLD FRONT ARE FORECAST TO BE
ONLY IN THE 60S.
FOR FRIDAY A SECONDARY UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE
PLAINS RE-ESTABLISHING THE COLDER AIRMASS. A FEW RAIN SHOWERS MAY
DEVELOP IN THE COLDER AIR IN THE EAST FA AROUND MEDICINE LODGE AND
WILL COVER WITH A LOW POP. THE GFS AND CANADIAN MODELS LOOK TO
DEEP WITH THE TROUGH AXIS THAN THE NEW ECMWF AND HAS MUCH MORE
PRECIPITATION BREAKING OUT. FOR NOW WILL SIDE WITH THE DRIER
ECMWF. HIGHS ON FRIDAY LOOK TO BE ONLY IN THE MID TO UPPER 5OS.
OVERNIGHT LOWS ON FRIDAY MORNING LOOK TO BE IN UPPER 30S TO MID
40S.
FOR NEXT WEEKEND DRY NORTHWESTERLY FLOW CONTINUES BEHIND THE UPPER
LEVEL TROUGH WITH A COLD AIRMASS IN PLACE AND HIGHS ONLY IN THE 40S
TO LOWER 50S. OVERNIGHT LOWS COULD GET DOWN BELOW THE FREEZING MARK
DEPENDING ON WHERE THE SURFACE RIDGE SETS UP AND WHERE WINDS CAN GO
LIGHT FOR BOTH SATURDAY AND SUNDAY MORNINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 603 AM CDT SUN OCT 21 2012
A WEAK UPPER LEVEL SHORTWAVE TROUGH WILL MOVE ACROSS WESTERN
KANSAS THIS AFTERNOON BUT LAYER MOISTURE IS LACKING FOR ANY
CONVECTION. A COLD FRONT WILL MOVE ACROSS THE TAF SITES AFTER
MIDNIGHT SHIFTING LIGHT AND VARIABLE WINDS TO THE NORTH TO
NORTHWEST AROUND 10KT. AHEAD OF THE FRONT DEEP MIXING IN THE WARM
SECTOR BY 21Z COULD LEAD TO 10-20KT SOUTH TO SOUTHWEST WINDS
THROUGH 00Z. MODEL FORECAST SOUNDINGS SHOW MID TO HIGH LEVEL
CLOUDINESS INCREASING AFTER MIDNIGHT. EXPECT VFR CONDITIONS THROUGH
THIS TAF PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 47 78 53 / 0 0 0 0
GCK 86 44 76 48 / 0 0 0 0
EHA 87 47 80 50 / 0 0 0 0
LBL 88 47 80 47 / 0 0 0 0
HYS 84 48 75 51 / 0 0 10 0
P28 90 55 83 59 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...KRUSE
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
410 AM CDT SUN OCT 21 2012
...UPDATED FOR LONG TERM...
.SYNOPSIS...
ISSUED AT 1100 PM CDT SAT OCT 20 2012
THE 21.00Z 250 HPA RAOB MAP SHOWED A STRONG 130 KT WESTERLY JET LOCATED
ACROSS SW OREGON. THIS JET WEAKENED SOMEWHAT ACROSS THE NORTHERN ROCKIES
AND THEN INCREASED TO AROUND 125 KT ACROSS THE NORTHERN PLAINS. AT 500
HPA, A SUBTROPICAL LOW WAS LOCATED SW OF CALIFORNIA. A BROAD TROF EXTENDED
ACROSS THE PACIFIC NORTHWEST. AT 700 AND 850 HPA, A WARM PLUME PREVAILED
ACROSS THE PLAINS. AT THE SFC, A FRONTAL SYSTEM WAS LOCATED ACROSS THE
WEST COAST. ANOTHER FRONTAL SYSTEM WAS LOCATED ACROSS THE CENTRAL CANADIAN
PRAIRIE PROVINCES INTO THE PLAINS. YET ANOTHER FRONTAL SYSTEM WAS LOCATED
OFFSHORE OF THE EAST COAST.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 115 AM CDT SUN OCT 21 2012
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS NEAR 20 DEGREES
ABOVE NORMAL.
THE SUBTROPICAL 500 HPA LOW MENTIONED IN THE SYNOPSIS WILL BECOME ABSORBED
IN THE SW FLOW ALOFT ACROSS THE DESERT SOUTHWEST TODAY. THIS FEATURE
WILL NOT MOVE ACROSS KANSAS UNTIL THE OVERNIGHT HOURS. THIS UL FEATURE
WILL EVENTUALLY MOVE A COLD FRONT ACROSS THE REGION. THIS FRONT
WILL NOT MOVE MUCH TODAY AND SW KANSAS WILL REMAIN IN THE WARM SECTOR.
850 HPA TEMPERATURES ACROSS SOUTH CENTRAL KANSAS LOOK TO BE VERY WARM
FOR OCTOBER (IN THE LOWER 20 DEG C). THIS COULD EASILY SUPPORT TEMPERATURES
AROUND 90 DEG F ACROSS SOUTH CENTRAL KANSAS. SURFACE DEWPOINTS WILL
ALSO INCREASE TODAY AND THE HRRR SHOWS SOME PATCHY FOG ACROSS SOUTH
CENTRAL KANSAS THIS MORNING. WINDS IN THE WAKE OF THE FROPA ARE NOT
EXPECTED TO BE STRONG DUE TO THE DEAMPLIFICATION OF THE SYNOPTIC WAVE
WITH TIME AND LACK OF STRONG HEIGHT FALLS ALOFT. AN INCREASE IN MID
TO HIGH LEVEL CLOUDS IS EXPECTED TONIGHT AND INTO TOMORROW MORNING.
OVERNIGHT LOWS INTO MONDAY MORNING ARE EXPECTED TO BE IN THE 40S DEG
F ACROSS WEST CENTRAL KANSAS TO 50S DEG F ACROSS SOUTH CENTRAL KANSAS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 405 AM CDT SUN OCT 21 2012
ON MONDAY AN UPPER LEVEL SUBTROPICAL SHORTWAVE TROUGH MOVES RAPIDLY
NORTHEASTWARD FROM NEW MEXICO ACROSS THE CENTRAL AND SOUTHERN
PLAINS. LAYER MOISTURE IS LIMITED WITH THIS SYSTEM SO WILL CONTINUE
WITH A DRY FORECAST. LIGHT NORTH WINDS BECOME LIGHT SOUTHEASTERLY
BEHIND A COLD FRONT WITH THE FRONTAL BOUNDARY STALLING OUT JUST
SOUTH OF THE OKLAHOMA BORDER. HIGH TEMPS WILL BE THE COOLEST IN THE
NORTH FROM SCOTT CITY TO HAYS IN THE MID 70S AND WARMER SOUTH FROM
THE UPPER 70S TO LOWER 80S.
FOR MONDAY NIGHT A WARM FRONT MOVES BACK NORTH FROM OKLAHOMA ACROSS
WESTERN KANSAS WITH LIGHT SOUTHEAST WINDS BECOMING SOUTH. 850MB
TEMPS RISE TO 22 TO 24C. THERE COULD BE SOME STRATUS IN THE EAST FA
FROM SAINT JOHN TO PRATT AS HIGHER DEWPOINTS RETURN. OVERNIGHT LOWS
ARE FORECAST TO BE MILD AND RANGE FROM THE UPPER 40S WEST TOWARDS
THE COLORADO BORDER TO AROUND 60 EAST FROM SAINT JOHN TO MEDICINE
LODGE.
FOR TUESDAY AND WEDNESDAY A STRONG UPPER LEVEL SHORTWAVE TROUGH
MOVES FROM THE WESTERN CONUS AND INTO THE 4 CORNERS REGION AND
ROCKIES. AHEAD OF THIS SYSTEM, WESTERN KANSAS WILL BE IN THE WARM
SECTOR WITH HIGHS IN THE MID TO UPPER 80S. THE SURFACE PRESSURE
GRADIENT TIGHTENS ACROSS WESTERN KANSAS ON WEDNESDAY AFTERNOON AS
PRESSURES FALL IN THE LEE OF THE ROCKIES. A DRYLINE WILL SET UP IN
THE AFTERNOON ACROSS CENTRAL KANSAS WITH VERY DRY SURFACE AIR IN THE
WEST. IF WINDS MIX DEEPLY ENOUGH IN THE WEST COULD BE CLOSE TO
CRITICAL FIRE WEATHER CONDITIONS. OVERNIGHT LOWS ARE FORECAST TO BE
MILD AND IN THE 50S.
ON THURSDAY THE UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE PLAINS
PUSHING A STRONG COLD FRONT ACROSS KANSAS. WILL KEEP A SMALL POP
GOING FOR A FEW THUNDERSTORMS FROM NEAR HAYS TO COLDWATER AND EAST
FOR WEDNESDAY NIGHT AND THURSDAY MORNING, HOWEVER CONFIDENCE IS LOW
WITH AN UPPER LEVEL DRY SLOT INTRUSION. THE BETTER CHANCE FOR
THUNDERSTORMS LOOKS EAST INTO CENTRAL KANSAS WITH THE DEEPER
MOISTURE. HIGHS ON THURSDAY BEHIND THE COLD FRONT ARE FORECAST TO BE
ONLY IN THE 60S.
FOR FRIDAY A SECONDARY UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE
PLAINS RE-ESTABLISHING THE COLDER AIRMASS. A FEW RAIN SHOWERS MAY
DEVELOP IN THE COLDER AIR IN THE EAST FA AROUND MEDICINE LODGE AND
WILL COVER WITH A LOW POP. THE GFS AND CANADIAN MODELS LOOK TO
DEEP WITH THE TROUGH AXIS THAN THE NEW ECMWF AND HAS MUCH MORE
PRECIPITATION BREAKING OUT. FOR NOW WILL SIDE WITH THE DRIER
ECMWF. HIGHS ON FRIDAY LOOK TO BE ONLY IN THE MID TO UPPER 5OS.
OVERNIGHT LOWS ON FRIDAY MORNING LOOK TO BE IN UPPER 30S TO MID
40S.
FOR NEXT WEEKEND DRY NORTHWESTERLY FLOW CONTINUES BEHIND THE UPPER
LEVEL TROUGH WITH A COLD AIRMASS IN PLACE AND HIGHS ONLY IN THE 40S
TO LOWER 50S. OVERNIGHT LOWS COULD GET DOWN BELOW THE FREEZING MARK
DEPENDING ON WHERE THE SURFACE RIDGE SETS UP AND WHERE WINDS CAN GO
LIGHT FOR BOTH SATURDAY AND SUNDAY MORNINGS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1200 AM CDT SUN OCT 21 2012
VFR CIGS EXPECTED THROUGH TAF PD. A LEE SURFACE LOW WILL CONTINUE
ACROSS SOUTHEASTERN COLORADO THIS AFTERNOON WITH AN APPROACHING
COLD FRONT BY EVENING. SOME PATCHY FOG POSSIBLE THIS MORNING BUT
THIS LOOKS TO REMAIN EAST OF THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 47 78 53 / 0 0 0 0
GCK 86 44 76 48 / 0 0 0 0
EHA 87 47 80 50 / 0 0 0 0
LBL 88 47 80 47 / 0 0 0 0
HYS 84 48 75 51 / 0 0 10 0
P28 90 55 83 59 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
115 AM CDT SUN OCT 21 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1100 PM CDT SAT OCT 20 2012
THE 21.00Z 250 HPA RAOB MAP SHOWED A STRONG 130 KT WESTERLY JET LOCATED
ACROSS SW OREGON. THIS JET WEAKENED SOMEWHAT ACROSS THE NORTHERN ROCKIES
AND THEN INCREASED TO AROUND 125 KT ACROSS THE NORTHERN PLAINS. AT 500
HPA, A SUBTROPICAL LOW WAS LOCATED SW OF CALIFORNIA. A BROAD TROF EXTENDED
ACROSS THE PACIFIC NORTHWEST. AT 700 AND 850 HPA, A WARM PLUME PREVAILED
ACROSS THE PLAINS. AT THE SFC, A FRONTAL SYSTEM WAS LOCATED ACROSS THE
WEST COAST. ANOTHER FRONTAL SYSTEM WAS LOCATED ACROSS THE CENTRAL CANADIAN
PRAIRIE PROVINCES INTO THE PLAINS. YET ANOTHER FRONTAL SYSTEM WAS LOCATED
OFFSHORE OF THE EAST COAST.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 115 AM CDT SUN OCT 21 2012
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS NEAR 20 DEGREES
ABOVE NORMAL.
THE SUBTROPICAL 500 HPA LOW MENTIONED IN THE SYNOPSIS WILL BECOME ABSORBED
IN THE SW FLOW ALOFT ACROSS THE DESERT SOUTHWEST TODAY. THIS FEATURE
WILL NOT MOVE ACROSS KANSAS UNTIL THE OVERNIGHT HOURS. THIS UL FEATURE
WILL EVENTUALLY MOVE A COLD FRONT ACROSS THE REGION. THIS FRONT
WILL NOT MOVE MUCH TODAY AND SW KANSAS WILL REMAIN IN THE WARM SECTOR.
850 HPA TEMPERATURES ACROSS SOUTH CENTRAL KANSAS LOOK TO BE VERY WARM
FOR OCTOBER (IN THE LOWER 20 DEG C). THIS COULD EASILY SUPPORT TEMPERATURES
AROUND 90 DEG F ACROSS SOUTH CENTRAL KANSAS. SURFACE DEWPOINTS WILL
ALSO INCREASE TODAY AND THE HRRR SHOWS SOME PATCHY FOG ACROSS SOUTH
CENTRAL KANSAS THIS MORNING. WINDS IN THE WAKE OF THE FROPA ARE NOT
EXPECTED TO BE STRONG DUE TO THE DEAMPLIFICATION OF THE SYNOPTIC WAVE
WITH TIME AND LACK OF STRONG HEIGHT FALLS ALOFT. AN INCREASE IN MID
TO HIGH LEVEL CLOUDS IS EXPECTED TONIGHT AND INTO TOMORROW MORNING.
OVERNIGHT LOWS INTO MONDAY MORNING ARE EXPECTED TO BE IN THE 40S DEG
F ACROSS WEST CENTRAL KANSAS TO 50S DEG F ACROSS SOUTH CENTRAL KANSAS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 251 PM CDT SAT OCT 20 2012
MEDIUM RANGE MODELS INDICATE A SOUTHWESTERLY FLOW ALOFT PREVAILING
ACROSS THE WESTERN HIGH PLAINS TO BEGIN THE PERIOD. MEANWHILE, AN
EMBEDDED UPPER LEVEL SHORTWAVE TROUGH WILL LIFT NORTHEAST OUT OF THE
DESERT SOUTHWEST ACROSS THE TEXAS PANHANDLE INTO NORTHERN OKLAHOMA
AND EASTERN KANSAS MONDAY. THIS SYSTEM WILL BRING THE POSSIBILITY
FOR SHOWERS AND THUNDERSTORMS TO EXTREME NORTHERN TEXAS, OKLAHOMA,
AND POTENTIALLY PORTIONS OF SOUTHEASTERN KANSAS MONDAY AFTERNOON AND
EVENING. HOWEVER, A SURFACE LOW PROJECTED GENERALLY ACROSS CENTRAL
KANSAS WITH AN ASSOCIATED DRYLINE EXTENDING SOUTHWARD INTO OKLAHOMA,
IS EXPECTED TO KEEP THE BULK OF AVAILABLE LOW LEVEL MOISTURE JUST
OFF TO OUR SOUTH AND EAST. COMBINED WITH A GENERALLY WEAK FLOW
ALOFT, THIS WILL RESULT IN FAIRLY DRY CONDITIONS ACROSS WESTERN
KANSAS MONDAY WITH ANY PRECIP DEVELOPMENT STAYING JUST OFF TO OUR
SOUTH AND EAST. THE DRY CONDITIONS WILL THEN CONTINUE THROUGH MID
WEEK AS A LARGER UPPER LEVEL TROUGH BEGINS TO APPROACH FROM THE
WEST.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL MONDAY EVEN AS A WEAK
COLD FRONT IS PROGGED TO PUSH SOUTHWARD JUST INTO SOUTHWESTERN
KANSAS EARLY IN THE DAY BEFORE STALLING OUT. THE NAM, GFS, AND ECMWF
SHOW H85 TEMPERATURES RANGING FROM THE LOWER TEENS(C) ACROSS WEST
CENTRAL KANSAS TO NEAR 20C ACROSS SOUTH CENTRAL KANSAS AS COOLER AIR
FILTERS SOUTH ON THE BACKSIDE OF A SURFACE LOW WORKING NORTHEAST
ALONG THE BOUNDARY. LOOK FOR HIGHS UP INTO THE 70S(F) FOR THE
MOST PART WITH LOWER 80S(F) POSSIBLE IN SOUTH CENTRAL KANSAS.
WARMER TEMPERATURES ARE LIKELY TUESDAY AS A LEE SIDE TROUGH
QUICKLY DEVELOPS ACROSS EASTERN COLORADO HELPING TO LIFT THE
STALLED FRONTAL BOUNDARY BACK NORTH ACROSS WESTERN KANSAS DURING
THE DAY. THE RETURN OF A LOW LEVEL SOUTHERLY FLOW WILL ENHANCE
WARM AIR ADVECTION INTO THE AREA WITH H85 TEMPERATURES BACK UP
INTO THE LOWER 20S(C) ACROSS CENTRAL AND SOUTHWEST KANSAS.
WIDESPREAD 80S(F) ARE EXPECTED FOR HIGHS TUESDAY AFTERNOON WITH
NEAR 90F POSSIBLE IN SOME LOCATIONS IN EXTREME SOUTHWEST KANSAS.
A COOLING TREND WILL THEN TAKE PLACE BY THE END OF THE WEEK AS A
BROAD UPPER LEVEL TROUGH BEGINS TO PUSH EAST THROUGH THE
INTERMOUNTAIN WEST INTO THE WESTERN HIGH PLAINS HELPING TO USHER
AN ATTENDANT COLD FRONT SOUTHEASTWARD INTO WESTERN KANSAS SOMETIME
DURING THE LATE WEDNESDAY TO THURSDAY TIME FRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1200 AM CDT SUN OCT 21 2012
VFR CIGS EXPECTED THROUGH TAF PD. A LEE SURFACE LOW WILL CONTINUE
ACROSS SOUTHEASTERN COLORADO THIS AFTERNOON WITH AN APPROACHING
COLD FRONT BY EVENING. SOME PATCHY FOG POSSIBLE THIS MORNING BUT
THIS LOOKS TO REMAIN EAST OF THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 47 77 55 / 0 0 0 0
GCK 86 44 75 51 / 0 0 0 0
EHA 87 47 77 52 / 0 0 0 0
LBL 88 47 78 54 / 0 0 0 0
HYS 84 48 71 54 / 0 0 0 0
P28 90 55 81 58 / 0 0 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1046 PM MDT SAT OCT 20 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 147 PM MDT SAT OCT 20 2012
MODELS HAVING A HARD TIME RESOLVING THE TEMPERATURE AND WIND FIELD
FOR THE CURRENT PERIOD. THIS ALONG WITH ANOTHER EXPECTED VARIABLE
WIND FIELD TONIGHT MAKE FOR A COMPLICATED MIN FORECAST. THERE WAS
A WIDE RANGE IN LOWS LAST NIGHT. USED A BLEND OF THE RUC AND NAM
FOR THE WINDS. SHOULD GET WARM AIR ADVECTION OVER THE FORECAST
AREA BEFORE THE PREFRONTAL TROUGH AND THEN COLD FRONT START MOVING
THROUGH. EXPECT ONCE AGAIN WHERE THE TROUGH LINE IS WILL BE WHERE
COOLEST MINS SHOULD BE BUT DO EXPECT A WIDE RANGE ONCE AGAIN BUT A
LITTLE WARMER THAN LAST NIGHT.
MODELS DIFFERING ON THE ARRIVAL OF THE NEXT COLD FRONT WHICH DOES
NOT LOOK TOO STRONG. MODELS HAVE TENDED TO SLOW THIS DOWN AND
LOOKS TO NOT BE THROUGH THE ENTIRE FORECAST AREA BY THE END OF MAX
HEATING TIME. THERE IS A 5 TO NEARLY 10 DEGREE DIFFERENCE IN MAXES.
USING A CLUSTER OF THE BEST RECENT PERFORMING GUIDANCE...2 METER
AND 850 MB TEMPERATURE BIASES SUPPORT A LITTLE WARMER MAXES...ESPECIALLY
IN THE SOUTHEAST HALF OF THE AREA. IT DOES LOOK LIKE A BIG GRADIENT
ACROSS THE AREA RANGING FROM THE MIDDLE TO UPPER 60S IN THE NORTHWEST
CORNER TO THE LOWER 80S IN THE SOUTHEAST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 235 PM MDT SAT OCT 20 2012
FOR SUNDAY NIGHT THROUGH MONDAY NIGHT...THE COLD FRONT WILL EXIT THE
AREA SUNDAY EVENING. MEANWHILE A CLOSED LOW WILL REMAIN ANCHORED
JUST OFF THE COAST OF THE PACIFIC NORTHWEST...WITH SOUTHWEST FLOW ALOFT
AND NUMEROUS SHORT WAVE TROUGHS MOVING OVER THE AREA. THE STRONGEST
UPPER LEVEL DISTURBANCE WILL BE THE REMNANTS OF THE STORM SYSTEM
CURRENTLY WEST OF BAJA CALIFORNIA...WHICH WILL APPROACH THE AREA
OVERNIGHT SUNDAY NIGHT/MONDAY MORNING. AHEAD OF THE DISTURBANCE
NAM/SREF SHOW SOME WEAK ISENTROPIC LIFT OVER THE FAR EASTERN PART OF
THE AREA AROUND 850 TO 880MB. HOWEVER IT IS VERY SHALLOW SO WILL
ONLY HAVE SILENT CHANCES IN FOR THOSE PERIODS FOR THE FAR EAST.
OTHERWISE AM NOT EXPECTING AN PRECIPITATION OVER THE AREA DURING
THIS TIME FRAME DUE TO THE A DRY AIR MASS IN PLACE.
FOR TUESDAY THROUGH SATURDAY...THE MAJORITY OF THE PERIOD WILL
REMAIN DRY. THE CLOSED LOW OFF THE COAST OF THE PACIFIC NORTHWEST
WILL MOVE ONSHORE WEDNESDAY NIGHT. MODELS DISAGREE WITH THE
DEVELOPMENT OF THE CLOSED LOW ONCE IT MOVES ON SHORE. THE
GFS/DGEX/UKMET/GEM DIVE THE CLOSED LOW SOUTH AT VARYING SPEEDS BEHIND A
COLD FRONT...WHILE THE 0Z ECMWF HAS A SHORT WAVE TROUGH KICK OUT OF
THE CLOSED LOW BEFORE IT MOVES ONSHORE...KEEPING BOTH FURTHER NORTH
ALONG THE US/CANADIAN BORDER.
MEANWHILE THE GFS HAS A COLD FRONT MOVING THROUGH WEDNESDAY
NIGHT...AND DEPENDING ON THE MODEL OF CHOICE...EITHER THE LEFT EXIT
OR RIGHT ENTRANCE OF THE 500MB JET OVER THE NORTHERN HALF OF THE
AREA. DESPITE THE MODEL DISAGREEMENT CONSENSUS HAS PRECIP CHANCES
OVER THE NORTHERN HALF OF THE AREA...WHICH SEEMS REASONABLE. ON A
SIDE NOTE THE 12Z ECMWF IS NOW IN LINE WITH THE OTHER MODELS REGARDING
THE TRACK OF THE CLOSED LOW AND FRONTAL PASSAGE...GIVING MORE WEIGHT
TO THE NOTION OF PRECIP CHANCES WEDNESDAY NIGHT. TEMPERATURES FOR
THE PERIOD WILL BE WELL ABOVE NORMAL TUESDAY...TRANSITIONING TO
BELOW NORMAL BEHIND THE COLD FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1045 PM MDT SAT OCT 20 2012
COLD FRONT IS MOVING ACROSS SOUTH DAKOTA AND CENTRAL WYOMING LATE THIS
EVENING. EXPECT FRONT TO REACH KMCK/KGLD AROUND 14Z. UNTIL THEN...
SOUTH TO SOUTHWEST SURFACE WINDS WILL RANGE FROM 5-15 KNOTS. WINDS
WILL SWITCH TO THE NORTH WITH FRONTAL PASSAGE...AND POSSIBLY GUST
TO 20 KNOTS. EXPECT ONLY CIRRUS/VFR CONDITIONS THROUGH THE FORECAST
PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
529 PM EDT SUN OCT 21 2012
.SYNOPSIS...
LOW PRESSURE WILL REMAIN NORTH OF THE REGION TONIGHT. HIGH
PRESSURE WILL BUILD DOWN FROM CANADA MONDAY INTO MONDAY NIGHT
AND REMAIN ACROSS THE REGION INTO MIDWEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE: ADJUSTED THE POPS USING THE DOWNSCALED NAM WHICH IS
ALIGNING WELL W/THE LATEST RADAR LOOP SHOWING SCATTERED SHOWERS
OVER THE CWA. SKY COVER WAS ADJUSTED AS WELL TO INCREASE THE
PERCENTAGES TO SHOW MORE CLOUDS THROUGH THE EVENING. TEMPERATURES
WERE ADJUSTED DOWNWARD INTO THE EVENING USING THE HRRR WHICH
SHOWED THE COOLING TREND NICELY.
PREVIOUS DISCUSSION...
SURFACE LOW PRESSURE ALONG WITH INTENSE UPPER LEVEL SYSTEM WILL
PASS TO THE NORTH OF THE STATE TONIGHT AND REMAIN OVER THE
MARITIMES MONDAY. THIS SYSTEM IN CONJUNCTION WITH STRONG HIGH
PRESSURE OVER THE SOUTHEASTERN STATES WILL COMBINE TO PRODUCE
STRONG PRESSURE GRADIENT AND GUSTY WINDS MONDAY. HAVE BLENDED THE
NAM12...GFS40...SREF AND ECMWF TO INITIALIZE THE POP GRIDS THEN
HAVE MANUALLY ADJUSTED THE MODEL COMBINATION. DO NOT EXPECT ANY
SIGNIFICANT QPF THIS PERIOD. FOR WINDS HAVE USED A BLEND OF GMOS
AND NAM12. TRANSITION TEMPERATURE AND DEW POINT OBSERVATIONS TO
GRIDS GENERATED WITH GMOS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
WHATS LEFT OF COLD ADVCN SC ACROSS WRN AND NRN PTNS OF THE FA
SHOULD CLR AWAY OVRNGT MON AS THE UPPER TROF CONTS TO MOVE E THRU
THE MARITIMES...ALLOWING FOR FOR BLO FZG LOW TEMPS. TUE SHOULD BE
FAIR AND COOL WITH INCREASING HI CLDNSS OVR WRN/SRN PTNS OF THE
FA AS A WEAK S/WV BRINGS SOME OVRNG PRECIP TO CNTRL AND SRN NEW
ENG. CLDNSS FROM THIS SYSTEM SHOULD REACH ITS NRN MOST EXTENT OVR
OUR FA TUE EVE AND OVR NGT AS THE SFC WV MOVES ESE OFF SE NEW ENG.
HI/MID CLDNSS THEN DIMINISHES N TO S ACROSS THE FA LATE TUE NGT
INTO WED AS SFC HI PRES RIDGE FROM CNTRL CAN STRENGTHENS OVR THE
FA WITH CONTD SEASONABLY COOL HI TEMPS AND THEN CHILLY OVRNGT
LOWS WED NGT WITH GOOD RADIATIONAL COOLING CONDITIONS DIRECTLY
UNDER THE SFC HI.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THU BEGINS SUNNY ACROSS THE FA...THEN SOME INCREASE IN HI/MID
CLDNSS FROM QB MOVES IN LATE IN THE DAY AS A WARM FRONT FROM THE
ERN GREAT LKS APCHS. HI TEMPS SHOULD RECOVER TO NEAR SEASONAL NORMS.
SHWRS AHEAD OF THIS FRONT COULD CLIP NW PTNS OF THE FA THU NGT AS
THE WARM FRONT TRAVERSES W TO E ACROSS THE FA BY 12Z FRI. WITH CLDNSS
AND MILDER AIR ACROSS THE REMAINDER OF THE REGION...OVRNGT LOWS
SHOULD BE MUCH MILDER.
FRI SHOULD BE FAIR AND SIGNIFICANTLY WARMER WITH HI/MID CLDNSS AT
TMS ACROSS THE N HALF OF THE FA. HI TEMPS SHOULD BE WELL IN THE
50S NORTH AND LOWER 60S SOUTH...AND THIS MAY BE CONSERVATIVE. A WEAK
COLD FRONT FROM QUEBEC THEN MOVES INTO THE FA FRI NGT WITH SOME
CLDNSS AND A SLGT CHC OF SHWRS. AFTWRDS...THIS FRONT WILL BACK
N OF THE REGION AS A WARM FRONT SAT WITH MORE IN THE WAY OF CLDNSS
THEN SHWRS. A DEEPENING UPPER TROF FROM THE MIDWEST ALONG WITH A
STRONGER SFC COLD FRONT FROM CNTRL CAN BRINGS THE NEXT CHC OF
SHWRS TO THE FA BEGINNING LATE SAT NGT ACROSS WRN AREAS AND
SPREADING TO THE REST OF THE REGION ON SUN. TEMPS WILL CONT MILD
TO WARM...ALTHOUGH NOT AS WARM DURG DAYLIGHT HRS DUE TO GREATER
CLD CVR AND/OR SHWRS AND INCREASING SRLY COMPONENT OF WINDS
BRINGING COOLER MARINE AIR OFF THE GULF OF ME/N ATLC.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: EXPECT VFR CONDITIONS THIS FORECAST PERIOD.
SHORT TO LONG TERM: MAINLY VFR XPCTD ALL TAF SITES THRU FRI.
&&
.MARINE...
NEAR TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR WIND GRIDS.
PRIMARY WAVE SYSTEM IS CURRENTLY LONG PERIOD SOUTHERLY WAVES 6-7
FEET/9-11 SECONDS WHICH WAS GENERATED IN SOUTHERLY FETCH OFF EAST
COAST YESTERDAY. THIS SYSTEM IS EXPECTED TO SUBSIDE TO 2-3 FEET BY
1200Z MONDAY...HOWEVER LOCAL WEST TO SOUTHEAST FETCH WILL DEVELOP
ACROSS GULF OF MAINE TONIGHT AS WINDS INCREASE IN OFF-SHORE
GRADIENT. THE SCA WILL THEREFORE BE KEPT IN PLACE. NEW SWAN/NAM
NOT AVAILABLE..WILL KEEP PREVIOUS SWAN WHICH IS IN LINE WITH LATEST
WNA TO MAINTAIN RESOLUTION CLOSE TO COAST.
SHORT TO LONG TERM: INITIALLY...SCA CONDITIONS MON NGT INTO TUE
MORN...THEN DIMINISHING TO WELL BLO SCA THRESHOLDS LATER TUE THRU
FRI. KEPT CLOSE TO WW3 WV HT GUIDANCE THRU THIS PTN OF THE FCST.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ052.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR ANZ050-051.
&&
$$
NEAR TERM...HEWITT/MIGNONE
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HEWITT/MIGNONE
MARINE...HEWITT/MIGNONE/VJN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
403 PM EDT SUN OCT 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE THE UPPER OHIO VALLEY WITH MORE SUNSHINE
AND WARM TEMPERATURES INTO MONDAY. A WARM FRONT WILL MOVE
NORTHEASTWARD THROUGH OHIO MONDAY NIGHT...WITH SHOWERS POSSIBLE
THROUGH TUESDAY NIGHT. WARM AIR AND DRY WEATHER WILL PERSIST
THROUGH THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH MONDAY/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED LOW IN
QUEBEC CONTINUING TO PULL AWAY FROM THE AREA. ON THE FAR
SOUTHWESTERN PERIPHERY OF THIS FEATURE...THE UPPER OHIO VALLEY IS
IN A NORTHWESTERLY FLOW. AT THE SURFACE...A HIGH...CENTERED NEAR
CENTRAL WEST VIRGINIA...IS SLOWLY MOVING NORTHEASTWARD. A WEST-
NORTHWESTERLY LOW-LEVEL FLOW OFF OF LAKE ERIE IS PROVIDING
MOISTURE ALONG WITH DIURNAL HEATING TO ALLOW BROKEN CUMULUS TO
DEVELOP ACROSS MOST OF THE AREA.
THIS AFTERNOON...THE SURFACE HIGH WILL CONTINUE TO SHIFT NORTHWARD
AND BRING A DRY AND WARMER DAY TO THE UPPER OHIO VALLEY. THE 850MB
FLOW WILL BACK TO MORE ZONAL...WITH CLOUD COVERAGE DIMINISHING
THIS EVENING WITH THE LOSS OF HEATING AND ALSO AS MOISTURE ADVECTS
EASTWARD. HIGH TEMPS ARE FAIRLY CLOSE TO LAMP GUIDANCE...RANGING
FROM THE MID 50S ACROSS THE EASTERN RIDGES TO NEAR 60 IN EASTERN
OHIO AND NORTHERN WV.
TONIGHT...A 500MB RIDGE WILL APPROACH FROM THE WEST...AND THE
SURFACE HIGH WILL SHIFT SLOWLY EASTWARD ACROSS WEST VIRGINIA. WITH
A DEEP LAYER OF DRY AIR OVER THE AREA...CLEAR SKIES AND NEAR CALM
WINDS ARE IN THE FORECAST OVERNIGHT. THIS SETUP WILL BE SUITABLE
FOR RADIATIONAL COOLING WITH LOWS NEAR NORMAL SEASONAL VALUES.
WITH COOLER AIR OVER RELATIVELY WARMER RIVERS...SOME RADIATIONAL
FOG WILL SET UP ALONG THE RIVER VALLEYS NEAR DAWN.
GFS/NAM MODEL SOUNDINGS SUPPORT ONLY LIMITED DEVELOPMENT OF
DIURNAL CUMULUS ON MONDAY WITH CLOUD COVERAGE INCREASING FROM THE
WEST IN THE LATE AFTERNOON AND EARLY EVENING AS A WARM FRONTAL
BOUNDARY LIFTS INTO THE OHIO VALLEY. ABUNDANT SUNSHINE EARLY ON
AND WARM AIR ADVECTION WILL PRODUCE HIGH TEMPS THAT ARE 1-2
DEGREES ABOVE A MAV/MET BLEND...AROUND 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
SHWRS XPCD TO FORM MON NGT ALONG DIFFUSE WMFNT IN WARM AIR ADVCTN
PATTERN...PSBLY ENHANCED TUE-TUE NGT BY LOW-AMPLITUDE SHRTWV TROF.
QPF NOT XPCD TO BE SGFNT. PCPN GRADIENT WILL BE SHARP...WITH
GREATEST CHC OF PCPN IN NRN ZONES IN CLOSEST PROXIMITY TO BNDRY.
RDG AT H5 WILL AMPLIFY WED OVER THE RGN...LEADING TO DECRG PCPN
CHCS. SLY LOW-LVL JET FROM MS RVR VLY WILL SPREAD OVER THE RGN AND
WILL ADVCT EWD TEMPS OF 18-19C AT H9...LEADING TO UNSEASONABLY
WARM AMS BY MID-WK. MAXIMA IN UPR 70S-NR 80 PSBL AS THE WK
PROGRESSES AND CLD CVR DECRS IN CVRG. /KRAMAR/
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
H5 RDG BUILDS EWD WED NGT AS SFC HIPRES MOVES EWD INTO ATLC. STG
SWLY FLOW ALOFT WILL SPREAD EWD ON THU AHD OF CLOSED LOW OVER
CANADA...YIELDING SLY SFC FLOW AS PRES FALLS TO THE NW OF FCST
AREA. MEANWHILE...A TROPICAL WAVE IS XPCD TO ADVC NWD ALONG ERN
CONUS...LEAVING FCST AREA BTWN THE TWO SYSTEMS.
CDFNT ASSOCIATED WITH THE CANADIAN SYSTEM WILL MOVE SLOWLY SEWD
THU BFR STALLING IN CNTRL OH. THIS BNDRY WILL BE THE FOCUS FOR ANY
PCPN LATE IN THE WK. POPS WERE FOCUSED IN WRN ZONES FRI AND WERE
INCRD SAT-SUN AS EJECTING JET MAXIMUM DRIVES BNDRY EWD.
TEMPS WILL RMN ABV NRML THU-FRI. IN WAKE OF CDFNT...TEMPS WILL
RETURN TO NEAR OR BLW-NRML LVLS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL ACROSS THE TERMINALS THROUGHOUT THE
MAJORITY OF THE TAF PERIOD AS HIGH PRESSURE CONTINUES TO BUILD IN
FROM THE SOUTH. DIURNALLY DRIVEN VFR CEILINGS WILL CLEAR TONIGHT
WITH WEST-SOUTHWESTERLY WINDS DECREASING TO NEAR CALM.
RIVER VALLEY FOG MAY DEVELOP NEAR DAWN ON MONDAY...ALTHOUGH
CONFIDENCE IS LOW. A TEMPO GROUP FOR MVFR VISIBILITIES IS FORECAST
WITH MODEL SUPPORT AT KZZV...ALTHOUGH IFR RESTRICTIONS CANNOT BE
RULED OUT IN THE 09Z-13Z WINDOW. KAGC/KHLG MAY ALSO HAVE NEAR DAWN
RESTRICTIONS...HOWEVER CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS AT
THIS POINT.
.OUTLOOK.../MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE MAJORITY OF THIS PERIOD.
THE BEST CHC FOR RESTRICTIONS TO VSBY AND CIGS WILL BE MON NGT
THRU TUE NGT WITH SHWRS...MAINLY AT NRN TERMINALS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
UPDATE...KRAMAR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
203 PM EDT SUN OCT 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE THE UPPER OHIO VALLEY WITH MORE SUNSHINE
AND WARMER TEMPERATURES INTO MONDAY. A WARM FRONT WILL THEN
MOVE NORTHEASTWARD THROUGH OHIO MONDAY NIGHT WITH PERHAPS SHOWERS
INTO TUESDAY. DRY CONDITIONS WILL FOLLOW WITH WARM TEMPERATURES
INTO FRIDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
INCREASE SKY COVERAGE ACROSS THE AREA FOR THIS AFTERNOON.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED LOW IN
QUEBEC CONTINUING TO PULL AWAY FROM AREA. ON THE FAR
SOUTHWESTERN PERIPHERY OF THIS FEATURE...THE UPPER OHIO VALLEY IS
IN A NORTHWESTERLY FLOW. AT THE SURFACE...A HIGH...CENTERED NEAR
ACROSS CENTRAL WEST VIRGINIA...IS SLOWLY MOVING NORTHEASTWARD. A
WEST-NORTHWESTERLY LOW-LEVEL FLOW OFF OF LAKE ERIE IS PROVIDING
MOISTURE ALONG WITH DIURNAL HEATING TO ALLOW FOR BROKEN CUMULUS TO
DEVELOP ACROSS MOST OF THE AREA.
THIS AFTERNOON...THE SURFACE HIGH WILL CONTINUE TO SHIFT NORTHWARD
AND BRING A DRY AND WARMER DAY TO THE UPPER OHIO VALLEY. THE 850MB
FLOW WILL BACK TO MORE ZONAL...WITH CLOUD COVERAGE DIMINISHING
THIS EVENING WITH THE LOSS OF HEATING AND ALSO AS MOISTURE ADVECTS
EASTWARD. HIGH TEMPS ARE FAIRLY CLOSE TO LAMP GUIDANCE...RANGING
FROM THE MID 50S ACROSS THE EASTERN RIDGES TO NEAR 60 IN EASTERN
OHIO AND NORTHERN WV.
TONIGHT...A 500MB RIDGE WILL APPROACH FROM THE WEST AND THE
SURFACE HIGH WILL SHIFT SLOWLY EASTWARD ACROSS WEST VIRGINIA. WITH
A DEEP LAYER OF DRY AIR OVER THE AREA...CLEAR SKIES AND NEAR CALM
WINDS ARE IN THE FORECAST OVERNIGHT. THIS SETUP WILL BE SUITABLE
FOR RADIATIONAL COOLING WITH LOWS NEAR NORMAL SEASONAL VALUES.
WITH COOLER AIR OVER RELATIVELY WARMER RIVERS...SOME RADIATIONAL
FOG WILL SETUP ALONG THE RIVER VALLEYS NEAR DAWN.
MONDAY...GFS/NAM MODEL SOUNDINGS SUPPORT ONLY LIMITED DEVELOPMENT
OF DIURNAL CUMULUS ON MONDAY WITH CLOUD COVERAGE INCREASING FROM
THE WEST IN THE LATE AFTERNOON AND EARLY EVENING AS A WARM FRONTAL
BOUNDARY LIFTS INTO THE OHIO VALLEY. ABUNDANT SUNSHINE EARLY ON
AND WARM AIR ADVECTION WILL AID HIGH TEMPS THAT ARE 1-2 DEGREES
ABOVE A MAV/MET BLEND...AROUND 10 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW AN UPPER LEVEL SHORT-
WAVE TROUGH WILL FLATTEN THE UPPER LEVEL FLOW MONDAY NIGHT AND
TUESDAY...INDUCING A WARM FRONT TO MOVE NORTHEASTWARD THROUGH OHIO
AND LAKE ERIE MONDAY NIGHT. THIS COULD PRODUCE SHOWERS ACROSS THE
UPPER OHIO VALLEY...MAINLY NORTH OF I-70 LATE MONDAY NIGHT INTO
TUESDAY...WITH POINTS NORTH ALONG THE I-80 CORRIDOR HAVING THE
HIGHEST CHANCE OF RAINFALL.
EVEN WITH INCREASED CLOUD COVER AND THE RISK FOR SHOWERS...LOWS
MONDAY NIGHT CAN BE 10 DEGREES WARMER THAN NORMAL WHILE TUESDAY`S
HIGHS CAN BE 10 TO 15 DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
- VERY WARM WEATHER WED - FRI WITH TEMPS NEARLY 10F ABOVE NORMAL
- HIGH CONFIDENCE FORECAST THROUGH THURSDAY
- LOW CONFIDENCE FORECAST FRIDAY AND SATURDAY
COMBINATION OF BUILDING HEIGHTS AT MID LEVELS AND SSW SURFACE FLOW
CORRELATES TO TEMPERATURES WELL ABOVE AVERAGE FOR LATE OCTOBER MID
WEEK. H8 TEMPS CLIMB INTO THE 13 TO 16C RANGE WED AND THUR. RECORD
HIGHS FOR THE 24TH AND 25TH OF OCT ARE IN THE LOWER 80S...SO DO NOT
FORESEE ANY BENCHMARKS BEING TAKEN DOWN. WITH ATMOSPHERE STAYING
WELL MIXED...INCREASE TEMPS SLIGHTLY ABOVE INHERITED GRIDDED DATA SET
FOR THE AFOREMENTIONED DAYS. THIS PUTS THE FORECAST JUST ABOVE THE
HIGHEST GUIDANCE NUMBERS ON MAX AND MIN TEMPS.
UNCERTAINTY GROWS THE REMINDER OF THE LONG TERM WITH DISCREPANCIES
OF WHEN THE BAROCLINIC ZONE WILL CROSS THE UPPER OHIO VALLEY. ECMWF
AND CANADIAN MODELS REMAIN IN GOOD AGREEMENT WITH FROPA THUR NGT
INTO FRI MORNING THEN A BREAK BEFORE A STRONG LOW PRESSURE
APPROACHES SAT NGT. ON THE OTHER HAND...GFS KEEPS FRONT AT BAY
UNTIL LATE SATURDAY WHEN A WAVE RIDES ALONG THE BOUNDARY AND
SUFFICIENT STEERING WINDS EXIST PERMITTING AN EASTWARD PROGRESSION
THROUGH THE COMMONWEALTH OF PA. MODEL PREFERENCE WAS ECMWF AND CMC
SOLUTIONS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL ACROSS THE TERMINALS THROUGHOUT THE
MAJORITY OF THE TAF PERIOD AS HIGH PRESSURE CONTINUES TO BUILD IN
FROM THE SOUTH. DIURNALLY DRIVEN VFR CEILINGS WILL CLEAR TONIGHT
WITH WEST-SOUTHWESTERLY WINDS DECREASING TO NEAR CALM.
RIVER VALLEY FOG MAY DEVELOP NEAR DAWN ON MONDAY...ALTHOUGH
CONFIDENCE IS LOW. A TEMPO GROUP FOR MVFR VISIBILITIES IS FORECAST
WITH MODEL SUPPORT AT KZZV...ALTHOUGH IFR RESTRICTIONS CANNOT BE
RULED OUT IN THE 09Z-13Z WINDOW. KAGC/KHLG MAY ALSO HAVE NEAR DAWN
RESTRICTIONS...HOWEVER CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS AT
THIS POINT.
.OUTLOOK.../MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE MAJORITY OF THIS PERIOD.
THE ONLY POTENTIAL FOR RESTRICTIONS WILL BE MONDAY NIGHT INTO
TUESDAY WITH WARM FRONTAL SHOWERS MAINLY NORTH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...WOODRUM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1114 AM EDT SUN OCT 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE THE UPPER OHIO VALLEY WITH MORE SUNSHINE
AND WARMER TEMPERATURES TODAY AND MONDAY. A WARM FRONT WILL THEN
MOVE NORTHEASTWARD THROUGH OHIO MONDAY NIGHT WITH PERHAPS SHOWERS
INTO TUESDAY. DRY CONDITIONS WILL FOLLOW WITH WARM TEMPERATURES
INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST TRENDS IN SKY COVERAGE AND TO ADD RIVER VALLEY FOG
FOR MONDAY MORNING.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A CLOSED LOW IN
QUEBEC CONTINUING TO PULL AWAY FROM AREA. ON THE FAR
SOUTHWESTERN PERIPHERY OF THIS FEATURE...THE UPPER OHIO VALLEY IS
IN A NORTHWESTERLY FLOW. AT THE SURFACE...A HIGH...CENTERED NEAR
HUNTINGTON...WEST VIRGINIA...IS SLOWLY MOVING NORTHEASTWARD. A
NORTHWESTERLY LOW-LEVEL FLOW OFF OF LAKE ERIE IS ALLOWING FOR
STRATOCUMULUS TO FILTER ACROSS LOCATIONS PRIMARILY NORTHEAST OF
A FRANKLIN-INDIANA LINE WITH CUMULUS DEVELOPING ACROSS THE EASTERN
RIDGES. OTHERWISE...SKIES ARE MOSTLY CLEAR ACROSS THE AREA.
TODAY...THE SURFACE HIGH WILL CONTINUE TO SHIFT NORTHWARD AND
BRING A DRY AND WARMER DAY TO THE UPPER OHIO VALLEY. AN INITIAL
NORTHWESTERLY 850MB FLOW OFF OF LAKE ERIE WILL INDUCE DIURNAL
CUMULUS ACROSS MUCH OF THE AREA TODAY. THE FLOW WILL BACK TO MORE
ZONAL TODAY...WITH CLOUD COVERAGE DIMINISHING THIS EVENING WITH
THE LOSS OF HEATING AND ALSO AS MOISTURE ADVECTS EASTWARD. HIGH
TEMPS ARE FAIRLY CLOSE TO LAMP GUIDANCE...RANGING FROM THE MID 50S
ACROSS THE EASTERN RIDGES TO NEAR 60 IN EASTERN OHIO AND NORTHERN
WV.
TONIGHT...A 500MB RIDGE WILL APPROACH FROM THE WEST AND THE
SURFACE HIGH WILL SHIFT SLOWLY EASTWARD ACROSS WEST VIRGINIA. WITH
A DEEP LAYER OF DRY AIR OVER THE AREA...CLEAR SKIES AND NEAR CALM
WINDS ARE IN THE FORECAST. THE SETUP WILL BE SUITABLE FOR
RADIATIONAL COOLING WITH LOWS NEAR NORMAL SEASONAL VALUES.
WITH COOLER AIR OVER WARMER RIVERS...SOME RADIATIONAL FOG WILL SETUP
ALONG THE RIVER VALLEYS NEAR DAWN.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL MAINTAIN WARM MOSTLY SUNNY CONDITIONS MONDAY.
LOWS TONIGHT WILL BE NEAR NORMAL. HIGHS MONDAY CAN BE NEARLY 10
DEGREES WARMER THAN NORMAL PER CONSENSUS OF RECENT GFS NAM AND
ECMWF MOS.
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW AN UPPER LEVEL SHORT-WAVE
TROUGH WILL FLATTEN THE UPPER LEVEL FLOW MONDAY NIGHT AND
TUESDAY...INDUCING A WARM FRONT TO MOVE NORTHEASTWARD THROUGH OHIO
AND LAKE ERIE MONDAY NIGHT. THIS COULD PRODUCE SHOWERS ACROSS THE
UPPER OHIO VALLEY...MAINLY NORTH OF I-70 LATE MONDAY NIGHT INTO
TUESDAY...WITH POINTS NORTH ALONG THE I-80 CORRIDOR HAVING THE
HIGHEST CHANCE OF RAINFALL.
EVEN WITH INCREASED CLOUD COVER AND THE RISK FOR SHOWERS...LOWS
MONDAY NIGHT CAN BE 10 DEGREES WARMER THAN NORMAL WHILE TUESDAY`S
HIGHS CAN BE 10 TO 15 DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
- VERY WARM WEATHER WED - FRI WITH TEMPS NEARLY 10F ABOVE NORMAL
- HIGH CONFIDENCE FORECAST THROUGH THURSDAY
- LOW CONFIDENCE FORECAST FRIDAY AND SATURDAY
COMBINATION OF BUILDING HEIGHTS AT MID LEVELS AND SSW SURFACE FLOW
CORRELATES TO TEMPERATURES WELL ABOVE AVERAGE FOR LATE OCTOBER MID
WEEK. H8 TEMPS CLIMB INTO THE 13 TO 16C RANGE WED AND THUR. RECORD
HIGHS FOR THE 24TH AND 25TH OF OCT ARE IN THE LOWER 80S...SO DO NOT
FORESEE ANY BENCHMARKS BEING TAKEN DOWN. WITH ATMOSPHERE STAYING
WELL MIXED...INCREASE TEMPS SLIGHTLY ABOVE INHERITED GRIDDED DATA SET
FOR THE AFOREMENTIONED DAYS. THIS PUTS THE FORECAST JUST ABOVE THE
HIGHEST GUIDANCE NUMBERS ON MAX AND MIN TEMPS.
UNCERTAINTY GROWS THE REMINDER OF THE LONG TERM WITH DISCREPANCIES
OF WHEN THE BAROCLINIC ZONE WILL CROSS THE UPPER OHIO VALLEY. ECMWF
AND CANADIAN MODELS REMAIN IN GOOD AGREEMENT WITH FROPA THUR NGT
INTO FRI MORNING THEN A BREAK BEFORE A STRONG LOW PRESSURE
APPROACHES SAT NGT. ON THE OTHER HAND...GFS KEEPS FRONT AT BAY
UNTIL LATE SATURDAY WHEN A WAVE RIDES ALONG THE BOUNDARY AND
SUFFICIENT STEERING WINDS EXIST PERMITTING AN EASTWARD PROGRESSION
THROUGH THE COMMONWEALTH OF PA. MODEL PREFERENCE WAS ECMWF AND CMC
SOLUTIONS.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE FORECAST EVERYWHERE EXCEPT KDUJ/KFKL TODAY AS
HIGH PRESSURE BUILDS IN FROM THE SOUTH. AT KDUJ/KFKL...MVFR
CEILINGS WILL SLOWLY LIFT TO VFR BY AROUND 22Z. WINDS WILL BE
SOUTHWESTERLY AT AROUND 10KTS THIS AFTERNOON WITH SCATTERED
DIURNAL VFR CUMULUS ACROSS MOST OF THE TERMINALS. SKIES WILL CLEAR
TONIGHT WITH WINDS BECOMING NEAR CALM.
RIVER VALLEY FOG MAY DEVELOP NEAR DAWN ON MONDAY...ALTHOUGH
CONFIDENCE IS TOO LOW TO INCLUDE IN ANY OF THE RIVER VALLEY TAFS
AT THIS TIME.
.OUTLOOK.../MONDAY THROUGH THURSDAY/...
VFR WILL PREVAIL THROUGH THE MAJORITY OF THIS PERIOD. THE ONLY
POTENTIAL FOR RESTRICTIONS WILL BE MONDAY NIGHT INTO TUESDAY WITH
WARM FRONTAL SHOWERS MAINLY NORTH.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...WOODRUM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
442 AM EDT SUN OCT 21 2012
.SYNOPSIS...
HIGH PRESSURE...OVER VIRGINIA...WILL PROVIDE THE UPPER OHIO
VALLEY WITH AN INCREASE IN SUNSHINE TODAY AND WARMER TEMPERATURES
MONDAY. THEN A WARM FRONT...MOVING NORTHEAST THROUGH OHIO...MAY
BRING SHOWERS MONDAY NIGHT INTO TUESDAY...BUT WILL BE FOLLOWED BY
CONTINUED WARM TEMPERATURES INTO AT LEAST FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN FORECAST CONCERN IS HOW QUICKLY CLOUDS WILL EXIT.
WILL FIRST CONCENTRATE ON THE WANING OF THE CYCLONIC FLOW ALOFT.
YESTERDAY`S MODELS WERE INDICATING THAT NW FLOW WOULD HOLD ON
THROUGH MUCH OF THE DAY. HOWEVER...LATEST MODEL DATA IS SHOWING A
QUICKER CHANGE TO THE FLOW...BECOMING MORE WESTERLY THIS MORNING.
ADDITIONALLY... THE COLD CORE ALOFT WILL BE SHUNTED TO THE NORTH
BY LATE MORNING WHICH WILL ALSO AID IN CLOUD DISSIPATION. AT THE
SURFACE...BROAD HIGH PRESSURE WILL BUILD INTO THE MID-ATLANTIC BY
EARLY AFTERNOON...TO PROVIDE AMPLE SUBSIDENCE...PARTICULARLY IN
THE SOUTH...TO ALLOW SOUTHERN AND WESTERN COUNTIES TO SEE LESS
CLOUDS AND HENCE MORE SUN EARLIER.
LATEST HIRES MODEL OUTPUT IS SHOWING CLOUDS DISSIPATING FASTER.
THIS LINES UP WELL WITH LATEST RUC SOUNDINGS WHICH SHOWS MOISTURE
LAYER DRYING OUT MORE QUICKLY THIS MORNING. STILL THINK THERE
WILL BE AT LEAST SCT CLOUDS ACROSS MUCH OF THE SOUTH THIS
MORNING AFTER SUNRISE...WITH BKN-OVC SKIES ACROSS THE NORTH.
HAVE ADDED PATCHY FOG SOUTH AND WEST OF PITTSBURGH PER RECENT
SURFACE DATA.
SUNSHINE WILL HAVE MORE INFLUENCE ON HIGH TEMPS ACROSS THE SOUTH
THAN OVER THE NORTH. TEMPERATURES SHOULD BE NEAR NORMAL LEVELS IN
THE SOUTHERN HALF...BELOW NORMAL IN THE NORTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
UPPER LEVEL RIDGE WILL MOVE ACROSS THE MIDWEST TONIGHT. HIGH
PRESSURE WILL REMAIN LOCKED OVER THE MID-ATLANTIC. RIDGE WILL
DRIFT EASTWARD MONDAY...AS WILL THE HIGH PRESSURE...ALLOWING FOR A
WARMER FLOW AT ALL LEVELS. EXPECT PLENTY OF SUNSHINE FOR MOST OF
MONDAY WITH ABOVE NORMAL TEMPS.
A SHORTWAVE TROUGH WILL FLATTEN THE UPPER LEVEL FLOW MONDAY NIGHT
AND TUESDAY. A SERIES OF SHORTWAVES WILL MOVE ACROSS THE NORTH IN
ZONAL FLOW...WHICH WILL PROVIDE THE RISK FOR SHOWERS. FOR
NOW...WILL KEEP THE HIGHEST POPS ACROSS THE NORTH...CLOSER TO THE
CENTER OF THE WAVES.
EVEN WITH INCREASED CLOUD COVER AND THE RISK FOR SHOWERS...
TUESDAY`S TEMPS WILL BE 10 TO 15 DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
- VERY WARM WEATHER WED - FRI WITH TEMPS NEARLY 10F ABOVE NORMAL
- HIGH CONFIDENCE FORECAST THROUGH THURSDAY
- LOW CONFIDENCE FORECAST FRIDAY AND SATURDAY
COMBINATION OF BUILDING HEIGHTS AT MID LEVELS AND SSW SURFACE FLOW
CORRELATES TO TEMPERATURES WELL ABOVE AVERAGE FOR LATE OCTOBER MID
WEEK. H8 TEMPS CLIMB INTO THE 13 TO 16C RANGE WED AND THUR. RECORD
HIGHS FOR THE 24TH AND 25TH OF OCT ARE IN THE LOWER 80S...SO DO NOT
FORESEE ANY BENCHMARKS BEING TAKEN DOWN. WITH ATMOSPHERE STAYING
WELL MIXED...INCREASE TEMPS SLIGHTLY ABOVE INHERITED GRIDDED DATASET
FOR THE AFOREMENTIONED DAYS. THIS PUTS THE FORECAST JUST ABOVE THE
HIGHEST GUIDANCE NUMBERS ON MAX AND MIN TEMPS.
UNCERTAINTY GROWS THE REMINDER OF THE LONG TERM WITH DISCREPANCIES
OF WHEN THE BAROCLINIC ZONE WILL CROSS THE UPPER OHIO VALLEY. ECMWF
AND CANADIAN MODELS REMAIN IN GOOD AGREEMENT WITH FROPA THUR NGT
INTO FRI MORNING THEN A BREAK BEFORE A STRONG LOW PRESSURE
APPROACHES SAT NGT. ON THE OTHER HAND...GFS KEEPS FRONT AT BAY
UNTIL LATE SATURDAY WHEN A WAVE RIDES ALONG THE BOUNDARY AND
SUFFICIENT STEERING WINDS EXIST PERMITTING AN EASTWARD PROGRESSION
THROUGH THE COMMONWEALTH OF PA. MODEL PREFERENCE WAS ECMWF AND CMC
SOLUTIONS.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
BROAD SWATH OF HIGH-BASED STRATOCU THAT FORMED UNDER THE CROSSING UPR
LOW PRES LOOK TO PERSIST FOR MUCH OF THE NGT GIVEN THE WWD AND SWD
EXTENT OF THE BLANKET. THOSE CLOUDS COMBINED WITH A PRES GRADIENT
SUFFICIENT TO MAINTAIN SOME SFC WND...SHOULD PRECLUDE FOG FORMATION
OVRNGT AT KPIT AND PORTS NORTH.
SO OVERALL...TAFS WILL BE VFR TODAY INTO TONIGHT...EXCEPT...KZZV WILL
HAVE PERIODS OF IFR FOG THROUGH 12Z...KFKL AND KDUJ CAN HAVE
PERIODS OF MVFR STRATOCUMULUS CEILINGS THROUGH 14Z.
OVERALL...THE TAFS FEATURE A VFR FORECAST...EXCEPT FOR A PRE-DAWN
MVFR MENTION AT THE AIRPORTS DISCUSSED ABOVE. REGARDLESS...GENL
VFR WL RTN FOR ALL AS THE HIGH PRES BUILDS ON SUNDAY PROGRESSES.
.OUTLOOK.../MONDAY THROUGH THURSDAY/...
GENL VFR IS ANTICIPATED INTO AT LEAST TUESDAY...AND PERHAPS
THROUGH THURSDAY DUE TO UNCERTAINTIES REGARDING TRACK OF THE NEXT
LOW PRES SYS AND ITS IMPACTS ON THE UPPER OHIO VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1046 PM CDT MON OCT 22 2012
.UPDATE...
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
/ISSUED 357 PM CDT MON OCT 22 2012/
THE FIRST HALF OF THE PERIOD WILL BE WARM WITH MORNING FOG AND LIGHT
RAIN/DRIZZLE ON TUESDAY...FOLLOWED BY SOME SHOWERS AND THUNDERSTORMS
FOR WEDNESDAY LINGERING INTO THURSDAY. MUCH COOLER TEMPERATURES ARE
EXPECTED FOR THE END OF THE WEEK WITH HIGHS RUNNING AROUND 10
DEGREES BELOW CLIMATOLOGY PUTTING THE MINNEAPOLIS STREAK OF 16
CONSECUTIVE MONTHS ABOVE NORMAL IN JEOPARDY.
TODAY THROUGH THURSDAY...AFTERNOON SATELLITE IMAGERY SHOWS HIGH
CLOUDS MOVING WITH THE SOUTHWEST FLOW ACROSS THE HIGH PLAINS. LOW
STRATUS LINGERED ACROSS THE MIDWEST KEEPING TEMPERATURES IN THE 50S
AND 60S...BUT AFTERNOON HIGHS MANAGED RANGED FROM THE 70S TO EVEN A
FEW 80S IN IOWA WHERE THERE WERE A FEW BREAKS IN THE CLOUDS. A
LARGER LOOK AT THE CURRENT WEATHER SHOWED A SHORTWAVE AND AREA OF
SHOWERS AND THUNDERSTORMS ACROSS OZARKS WITH ANOTHER BROAD
LONGWAVE TROUGH OFF THE WASHINGTON COAST. TONIGHT UPPER LEVEL
SOUTHWEST FLOW WILL CONTINUE TO INDUCE SOUTHERLY LOWER LEVEL FLOW
AND DRAW UP BOUNDARY LAYER MOISTURE FROM THE GULF. FORECAST
SOUNDINGS SHOW A THICK STRATUS DECK ADVECTING ACROSS THE
REGION...AND THE LOW LEVEL SATURATION MAY BE ENOUGH TO PRODUCE A
FEW HUNDREDTHS OF LIGHT PRECIP. GIVEN THE LOW VISIBILITIES ONGOING
ACROSS NEBRASKA...HAVE KEPT AREAS OF FOG IN THE GRIDS AS WELL.
THE CLOUDS SHOULD MIX OUT NEAR THE IA/MN BORDER TUESDAY AFTERNOON
WHICH WILL GREATLY INFLUENCE HIGH TEMPERATURES. THE LINGERING WARM
MOIST AIR AND POTENTIAL FOR OVERCAST SKIES WILL KEEP TUESDAY NIGHT
TEMPERATURES IN THE 50S ACROSS THE REGION. ON WEDNESDAY AT 125KT
H250JET WILL MOVE ACROSS THE MN/DAKOTA BORDER WHILE THE H850
THERMAL GRADIENT TIGHTENS OVER CENTRAL MINNESOTA. THE SURFACE
FRONT WILL BY DEFINITION HAVE A TROUGH OF LOW PRESSURE ASSOCIATED
WITH IT...WITH AN UNSTABLE WARM SECTOR LOCATED ACROSS SOUTHEAST
MINNESOTA INTO WISCONSIN. GIVEN THE STRONG FRONTOGENETIC FORCING
AND INCREASING UPPER LEVEL DYNAMICS...A FEW STRONG TO SEVERE
STORMS MAY BE POSSIBLE MAINLY SOUTH AND EAST OF HWY 169 IN
MINNESOTA AND I94 IN WISCONSIN. THE MOST LIKELY SCENARIO WILL BE
OVERCAST SKIES AND CLOUDS EARLY ON WEDNESDAY WITH A CLEARING TREND
BY MID DAY ACROSS THE SOUTHEAST AND PERHAPS A FEW THUNDERSTORMS
DURING THE AFTERNOON AND LASTING THROUGH THE EVENING AS THEY
DEVELOP INTO A LINE AND MOVE INTO WISCONSIN. FOR WEDNESDAY NIGHT
INTO THURSDAY FORECAST MODELS CONTINUE TO SHOW A BAND OF PRECIP
DRIVEN BY FRONTOGENETIC FORCING IN THE H850 TO H700 LAYER...SO
SHOULD HAVE SOME COOL RAIN WITH NORTHWEST WINDS LASTING THROUGH
THURSDAY...WITH A FEW SNOWFLAKES POSSIBLE ACROSS THE NORTHWEST.
FRIDAY THROUGH MONDAY...AN ARCTIC AIRMASS WILL BRING MUCH COOLER
TEMPERATURES FOR FRIDAY AND THE REST OF THE WEEKEND. H850 TEMPS OF
-5 TO -9C WILL KEEP SURFACE HIGH TEMPS IN THE LOWER 40S...AND LOW
TEMPS IN THE 20S. THE GFS 22.12 BRINGS A SHORTWAVE AND SOME LIGHT
PRECIP ACROSS THE REGION FOR MONDAY...WHILE THE ECMWF HAS A DRIER
SOLUTION. ASIDE FROM ADJUSTING TEMPS UPWARD IN THE METRO
AREA...DID NOT DEVIATE FROM A MODEL CONSENSUS DURING THIS
TIME FRAME.
&&
.AVIATION.../06Z TAF ISSUANCE/
THINKING HAS NOT CHANGED MUCH FROM 00Z SET OF TAFS AND
ACCOMPANYING DISCUSSION. ONLY REAL CHANGE WAS FOR A SOMEWHAT
SLOWER INVASION OF LOWER CEILINGS AND VISIBILITIES... WHICH WAS
MENTIONED AS A POSSIBILITY. THINGS SEEM TO BE IN LINE WITH SREF
GUIDANCE AND LATEST NARRE-TL AS WELL. DIDN/T CHANGE PREVIOUS
FORECAST MUCH OTHER THAN TO PUSH BACK TIMING SOME... AND OTHERWISE
KEPT THINGS FAIRLY PESSIMISTIC THROUGH THE DAY AS VERY MOIST
PROFILE MOVES ACROSS THE AREA OVERNIGHT THROUGH MOST OF THE DAY ON
TUESDAY. IMPROVEMENT SHOULD OCCUR ON THE BACKSIDE OF UPPER WAVE
AND SURFACE IMPULSE LATE TOMORROW AFTERNOON AND TOMORROW
EVENING... SO DID ALLOW FOR RETURN OF VFR CONDITIONS DURING THAT
TIME FRAME.
KMSP...THERE IS DEFINITELY SOME UNCERTAINTY STILL ON THE TIMING OF
ARRIVAL AND DEPARTURE OF IFR AND LIFR CONDITIONS... AS WELL AS
EXACTLY HOW LOW CEILINGS AND VISIBILITIES WILL GET LATE TONIGHT
AND TUESDAY MORNING. STAYED CLOSE TO PREVIOUS FORECAST... WHICH IS
IN LINE WITH SOME OF THE UPSTREAM OBSERVATIONS AS WELL AS THE
TIME-HEIGHT FORECASTS FROM THE RAP AND NAM. HOWEVER... TIMING
COULD STILL VARY SEVERAL HOURS FROM INDICATED... PARTICULARLY WITH
THE IMPROVEMENT OF CONDITIONS ON TUESDAY.
/OUTLOOK FOR KMSP/
WEDNESDAY...IFR CEILINGS AND VISIBILITIES POSSIBLE... MVFR LIKELY.
WINDS NORTHEAST 5-10 KTS.
THURSDAY...IFR CEILINGS AND VISIBILITIES EXPECTED IN THE MORNING. WINDS
NORTHWEST 10-15 KTS.
FRIDAY...VFR CONDITIONS EXPECTED. WINDS NORTHWEST AROUND 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
857 PM MDT MON OCT 22 2012
.SHORT TERM...VALID FOR TUE AND WED...
MID LEVEL WARM FRONT...WHICH PRODUCED WIDESPREAD MODERATE
PRECIPITATION...HAS LIFTED NORTH OF OUR FORECAST AREA. NEXT
FEATURE IS A MID LEVEL SHORT WAVE RIDING THE NOSE OF A STRONG
500MB JET MAKING ITS WAY THROUGH THE UTAH ROCKIES. RADAR ECHOES
PICKING UP OVER THE BIG HORNS. THE GFS AND HRRR MODELS SEEM TO BE
HANDLING THIS THE BEST AND LEANED ON THEM FOR THIS UPDATE. THESE
MODELS TAKE DECENT Q VECTOR FORCING ACROSS OUR CENTRAL AND EASTERN
ZONES LATER TONIGHT. WILL BUMP POPS UP OVER THE EAST AFTER
MIDNIGHT. WILL ALSO ADD SOME FOG TO MANY AREAS THAT PICKED UP
PRECIP TODAY AND ARE DEALING WITH DEWPOINT DEPRESSIONS LESS THAN 4
DEGREES AT THIS TIME. THIS INCLUDES LIVINGSTON AND BILLINGS. BT
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
CONFIDENCE IN THE EXTENDED FORECAST WAS HIGHER THU THROUGH SAT
THAN IN THE SUN THROUGH MON TIME FRAME AS MODELS WERE IN FAIRLY
GOOD AGREEMENT THROUGH SAT...BUT MARKEDLY DIFFERENT FOR SUN AND
MON. CONFINED FORECAST ADJUSTMENTS TO THE EARLIER PERIODS.
THERE WAS GOOD MODEL AGREEMENT THAT JET ENERGY WILL REMAIN S OF
THE FORECAST AREA THROUGH SAT WITH BROAD TROUGHING OVER THE
NORTHERN PART OF THE COUNTRY. THIS PATTERN LEFT THE FORECAST AREA
UNDER WEAK FLOW ALOFT FOR THU...THEN A NW FLOW WITH WEAK
SHORTWAVES IN THE FLOW FOR FRI AND SAT. WILL HAVE LOW
PRECIPITATION CHANCES FOR THE PLAINS WITH HIGHER CHANCES FOR
UPSLOPE AREAS...AND BELOW NORMAL TEMPERATURES. POPS LOOKED GOOD
FOR THU AND THU NIGHT. DID LOWER TEMPERATURES ON THU A FEW
DEGREES GIVEN 850 MB TEMPERATURES RANGING FROM NEAR ZERO DEGREES
C SW TO AROUND -6 DEGREES C NE. CONTINUED HIGH CHANCE MOUNTAIN
POPS FRI AND FRI NIGHT WITH LOW POPS OVER THE PLAINS AS PACIFIC
MOISTURE WAS FORECAST TO FLOW INTO THE REGION IN FASTER FLOW
ALOFT. ADJUSTED FRI HIGHS BASED ON 850 MB TEMPERATURES. SAT WILL
BE SIMILAR TO FRI.
12Z GFS CAME IN WITH A TROUGH FOR SUN THAT MOVES OUT OF THE AREA
ON MON. ECMWF CONTINUED TO ADVERTISE A RIDGE FOR THIS PERIOD. THUS
MADE NO CHANGES TO THE INHERITED FORECAST OF LOW POPS AND A
WARMING TREND. ARTHUR
&&
.AVIATION...
AREAS OF HIGH ELEVATION SNOW ALONG WITH LOW ELEVATION RAIN
...WILL REDEVELOP OVERNIGHT. AS A RESULT...PERIODS OF IFR/LIFR
CONDITIONS ARE POSSIBLE OVER ALL ROUTES. WEST SOUTHWEST WINDS WILL
BEGIN TO INCREASE BY EARLY TUESDAY MORNING...AND CONTINUE THROUGH
THE AFTERNOON IN MOST AREAS...BUT ESPECIALLY FROM KBIL WEST.
MOUNTAIN OBSCURATIONS WILL CONTINUE THROUGH TUESDAY. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 037/053 029/038 023/032 019/034 022/038 025/046 029/051
32/W 43/W 32/J 22/J 22/W 22/W 22/W
LVM 032/048 024/036 017/036 017/038 017/039 026/046 029/047
32/W 43/J 43/J 32/W 32/W 22/W 22/W
HDN 038/058 030/041 025/035 019/036 021/041 018/045 024/050
42/W 33/W 32/J 22/W 22/W 22/W 22/W
MLS 039/055 029/040 023/033 019/032 019/036 016/040 022/046
42/W 33/W 21/B 22/J 22/W 22/W 22/W
4BQ 038/059 030/039 025/034 019/032 020/036 018/040 024/049
42/W 34/W 31/B 22/J 22/J 12/W 22/W
BHK 035/058 030/039 024/032 020/030 019/035 018/040 024/046
42/W 32/W 21/B 22/J 22/J 22/W 22/W
SHR 037/056 031/039 024/034 020/037 021/040 018/043 024/051
62/W 34/W 43/J 32/W 22/W 22/W 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
329 AM CDT SUN OCT 21 2012
.SHORT TERM...TODAY THROUGH MONDAY...
LATEST WATER VAPOR IMAGERY SHOWS A LARGE UPPER LOW CIRCULATING
OVER QUEEN CHARLOTTE ISLANDS SENDING A SOUTHWESTERLY FLOW INTO
NORTH DAKOTA WITH PERIODIC SHORTWAVES MOVING THROUGH. THIS WILL BE
THE TREND THROUGH MONDAY AND BEYOND. SEVERAL JET STREAKS WERE
EVIDENT MOVING THROUGH THE AFOREMENTIONED LONGWAVE TROUGH...AIDING
THE LIFT/PRECIPITATION ACROSS NORTH DAKOTA EARLY THIS MORNING. AT
THE SURFACE...A COLD FRONT WAS MOVING THROUGH CENTRAL NORTH DAKOTA
WITH SCATTERED RAIN SHOWERS MOST CONCENTRATED BETWEEN BISMARCK AND
GARRISON...AND BETWEEN JAMESTOWN AND RUGBY. THE RUC CONTINUES TO
HANDLE THE CURRENT PICTURE WELL AND HAVE FOLLOWED IT THROUGH THE
MORNING HOURS WITH THE PRECIPITATION WANING AS IT EXITS THE
RUGBY/HARVEY AREA BETWEEN 15Z AND 18Z TODAY. ELSEWHERE...EXPECT A
DRY DAY BUT MUCH COOLER AS THE SHORTWAVE EXITS EARLY THIS
MORNING. THE NEXT SHORTWAVE ARRIVES IN OUR SOUTHWEST ZONES AFTER
00Z MONDAY WITH GOOD CONSENSUS ON THE AREAL COVERAGE OF
PRECIPITATION SUNDAY NIGHT. EXPECT A CHC TO LIKELY POPS ACROSS
THE WEST...SPREADING NORTHEAST EARLY MONDAY MORNING. THERE COULD
BE A BRIEF MIX OF RAIN AND SNOW NORTHWEST LATE SUNDAY NIGHT AND
NORTH CENTRAL EARLY MONDAY MORNING AS AN AREA/POCKET OF SUBFREEZING
H85 AIR MATERIALIZES. FOR MONDAY...SOME UNCERTAINTY EXISTS ON HOW
FAR EAST THE PRECIPITATION SHIELD EXPANDS...WITH THE NAM AND SREF
KEEPING MOST OF THE QPF IN THE WEST...WHILE THE GFS AND ECMWF ARE
A BIT MORE OPTIMISTIC WEST AND ALSO ACROSS THE CENTRAL PORTION.
HAVE UTILIZED A BLEND WITH A CHC OF POPS WEST TAPERING TO SLIGHT
CHC EAST.
AHEAD OF THE COLD FRONT YESTERDAY/SATURDAY...H85 TEMPS RANGED FROM
+10C NORTH TO +14C SOUTH. BEHIND THE COLD FRONT TODAY...H85 TEMPS
WILL RANGE FROM +2C NORTH TO +6C SOUTH. THUS MUCH COOLER TODAY
WITH EXPECTED HIGHS IN THE UPPER 40S NORTH TO UPPER 50S SOUTH.
MONDAY LOOKS TO BE A REPEAT PERFORMANCE WITH THE HIGH TEMPERATURES.
OVERNIGHT LOWS SUNDAY NIGHT WILL RANGE FROM 30 NORTH TO 40 FAR SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY.
AN ACTIVE PATTERN IS EXPECTED. MAIN CHALLENGES WILL BE TIMING OF
PRECIP THROUGH THE PERIOD AND POSSIBLE PRECIP TYPES. SOME MODEL
DIFFERENCES EXIST WITH EVOLUTION OF WESTERN CONUS TROUGH INITIALLY
OVER THE WEST. GFS CUTS OFF DEEPER 500MB LOW OVER SOUTHERN CANADA
NEAR NORTH DAKOTA BY THURSDAY WHILE ECMWF IS WEAKER WITH THIS
FEATURE. BOTH MODELS DEEPEN UPPER LOW BY LATE WEEK AND TAKE IT
TOWARD HUDSON BAY LEAVING OUR REGION IN COLD CYCLONIC FLOW. EVEN
WITH DIFFERENCES IN THESE FEATURES...MODELS IN DECENT AGREEMENT
WITH SENSIBLE WEATHER IMPACTS ON OUR REGION. TUESDAY WILL BE LAST
MILD DAY WITH SOUTHERLY FLOW AHEAD OF COLD FRONT. BY 00Z
FRI...850MB TEMPS RANGE FROM AROUND -6C SOUTH TO -8C NORTH AND
DECREASE A COUPLE MORE DEGREES BY FRI AND SAT.
CONSEQUENTLY...EXPECT MAX TEMPS BY FRI AND SAT TO ONLY BE IN THE
30S F. BEST PRECIP CHANCES APPEAR TO BE MONDAY NIGHT POSSIBLY
MIXING WITH SNOW NORTH AND NORTHWEST. HARD TO RULE OUT PRECIP IN
ANY GIVEN TIME PERIOD THE REMAINDER OF THE EXTENDED...BUT MODELS
INDICATE BETTER CHANCE ACROSS SOUTHERN AND EASTERN PARTS OF AREA
CLOSER TO SURFACE LOW AND FRONTAL SYSTEM. IN TERMS OF PRECIP
TYPE... TEMPERATURES INITIALLY WILL SUPPORT RAIN PRECIP TYPE
DURING THE DAY THROUGH MIDWEEK THEN SUPPORT SNOW DAY/NIGHT BY LATE
WEEK WHEN COLDER AIR IS IN PLACE. HOWEVER...PRECIP PROBABILITIES
FROM MID TO LATE WEEK ARE RELATIVELY LOW FOR ANY GIVEN PERIOD...IN
THE SLIGHT CHANCE TO CHANCE RANGE.
&&
.AVIATION...A COLD FRONT AND ASSOCIATED SHOWERS CONTINUE TO PUSH
EASTWARD ACROSS THE STATE AS OF 08Z SUNDAY. DESPITE SHOWERS...EXPECT
VFR CONDITIONS AT TAF SITES THROUGH SUNDAY. NORTHERLY WINDS ARE
EXPECTED...MAINLY IN THE 10-15 KT RANGE. ANOTHER SYSTEM WILL BRING
SHOWERS TO SOUTHWESTERN ND SUNDAY EVENING AND SPREAD NORTHEASTWARD
SUNDAY NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM/AVIATION....JNS
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1018 PM CDT MON OCT 22 2012
.DISCUSSION.../ISSUED AT 1018 PM CDT/
FORECAST GENERALLY LOOKS IN GOOD SHAPE TONIGHT. EXPECT CLOUDY SKIES
TO PERSIST THROUGH THE NIGHT...WITH THE CLOUD DECK LOWERING BY
MORNING. AREAS OF DRIZZLE AND FOG SHOULD EXPAND LATER TONIGHT AS
WELL. TRICKY FORECAST FOR TUESDAY. SOME OF THE NEWER GUIDANCE IS
SUGGESTING CLOUDS WILL BE SLOWER TO ERODE THAN PREVIOUSLY FORECAST.
THUS DELAYED CLEARING SOME AND EXTENDED THE DRIZZLE AND FOG INTO MID
MORNING. WILL EVENTUALLY SEE CLEARING FROM WEST TO EAST THROUGH THE
AFTERNOON...WITH EXACT TIMING HAVING BIG IMPLICATIONS ON HIGH
TEMPERATURES. DECIDED TO LEAVE HIGH TEMPERATURE FORECAST AS IS FOR
NOW. BUT LATEST NAM AND RAP WOULD SUGGEST THE SLOWER EROSION OF
CLOUDS COULD KEEP HIGHS FIVE TO TEN DEGREES COOLER THAN CURRENT
FORECAST ALONG AND EAST OF INTERSTATE 29. MEANWHILE MOST SREF
MEMBERS ARE LESS AGGRESSIVE WITH THE COOLER TEMPERATURES. THUS WILL
LET MIDNIGHT SHIFT EVALUATE FURTHER AND MAKE NECESSARY ADJUSTMENTS.
/CHENARD
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
MVFR STRATUS IS THE DOMINANT CATEGORY IN THE SIOUX FALLS FORECAST
AREA AT THIS TIME. ONE MINOR EXCEPTION EXISTS WITH VFR IN OUR
EXTREME SOUTHEASTERN ZONES AROUND SPENCER AND STORM LAKE IOWA DUE TO
SLIGHTLY DRIER LOW LEVEL AIR. OVERALL...CONFIDENCE IS FAIRLY LOW
WITH THE DETAILS IN THIS AVIATION FORECAST TONIGHT AND TUESDAY
MORNING. THE HUMIDITY TIME SECTIONS AND MOISTURE FIELDS OFF OF THE
NAM AND GFS CONTINUE TO PAINT A PICTURE OF MVFR TO IFR STRATUS IN
MUCH OF OUR FORECAST AREA TONIGHT...WITH THE GFS BEING A BIT MORE
PESSIMISTIC WITH THE OUTLOOK THEN THE NAM. FOR NOW...HEDGED TOWARD A
GRADUAL LOWERING OF THE VISIBILITY AND CEILINGS THROUGH THE NIGHT AS
THE SURFACE BASED TEMPERATURE INVERSION BECOMES STRONGER AND LOWERS
CLOSER TO THE GROUND. AT THIS TIME...RIGHT NOW BOTH THE HUMIDITY
TIME SECTIONS OFF OF THE NAM AND GFS POINT TO CLEARING TO A VFR
CATEGORY DURING THE LATE MORNING HOURS FOR MUCH OF OUR FORECAST AREA
ON TUESDAY. HOWEVER ONE EXCEPTION EXISTS NEAR KSUX IN NORTHWEST IOWA
WHERE HIGHER LEVELS OF MOISTURE AROUND 2000 TO 2500 FEET STAY
ENTRENCHED NEARLY ALL DAY TUESDAY AS MOISTURE WORKS THROUGH EASTERN
NEBRASKA. FOR NOW WE DID SCATTER OUT SIOUX CITY FOR TUESDAY
AFTERNOON...BUT THIS WILL HAVE TO BE WATCHED AS THERE IS A CHANCE
THEY COULD STAY MVFR BROKEN CEILINGS AT LEAST THROUGH MID AFTERNOON.
WILL ALTER THESE FORECASTS IF NEED BE AFTER THE 00Z DATA COMES IN.
/MJF
&&
.PREVIOUS DISCUSSION...
PRIMARY FORECAST CONCERNS ARE DRIZZLE/FOG SCENARIO TONIGHT...PRECIP
CHANCES MIDWEEK...THEN BELOW NORMAL TEMPERATURES INTO THE WEEKEND.
TONIGHT...FORECASTER CONFIDENCE: MODERATE.
A BROAD AREA OF LOW PRESSURE WILL DEVELOP OVER THE NRN PLAINS
AHEAD OF A SEASONABLY STRONG UPPER LEVEL TROUGH MOVING THROUGH THE
INTERMOUNTAIN WEST. ALTHOUGH LARGE SCALE ASCENT WILL BE RATHER
WEAK OVERNIGHT...THE COMBINATION OF PLENTIFUL BOUNDARY LAYER
MOISTURE /SPEC HUMIDITY AOA 8 G/KG/ AND WEAK LOW LEVEL LIFT IS
EXPECTED TO PRODUCE AREAS OF FOG/DRIZZLE OVER PORTIONS OF THE AREA.
NOT EXPECTING MUCH IN THE WAY OF QPF /MAYBE A COUPLE HUNDREDTHS/
HOWEVER DO BELIEVE A FEW AREAS ALONG AND EAST OF THE JAMES VALLEY
WILL SEE MEASURABLE RAINFALL. FOG MAY ALSO BE A CONCERN...BUT
DIFFICULT TO PINPOINT HOW DENSE IT MAY GET. FUTURE SHIFTS WILL HAVE
MONITOR VSBY TRENDS.
TUESDAY AND TUESDAY NIGHT...FORECAST CONFIDENCE: LOW TO MODERATE.
RESIDUAL STRATUS/FOG/DRIZZLE IS LIKELY EARLY TUESDAY
MORNING...BEFORE AN INCREASING S/SWLY LOW LEVEL FLOW GRADUALLY
NUDGES THE STRATUS DECK NORTH/EAST OF THE FORECAST AREA. MODELS CAN
STRUGGLE WITH THE EROSION/MOVEMENT OF STRATUS SO THERE IS SOME
UNCERTAINTY HOW QUICKLY CLOUDS MAY ERODE. ATTM...MODEL CONSENSUS
PUSHES HIGHER LOW LEVEL RH VALUES OUT BETWEEN 15-18Z TUE AND THIS
SEEMS REASONABLE. WILL CONTINUE TO BANK ON SEEING AT LEAST PARTLY
CLOUDY SKIES TUESDAY...WHICH WHEN COMBINED WITH H8 TEMPS +13 TO +18C
RANGE SHOULD ALLOW FOR VERY MILD TEMPS IN THE 70S TO NEAR 80F.
INCREASING CLOUDS ARE LIKELY TUESDAY NIGHT...BUT WILL MAINTAIN DRY
CONDITIONS FOR NOW.
WEDNESDAY THROUGH THURSDAY...FORECASTER CONFIDENCE: MODERATE TO HIGH.
UPPER TROUGH WILL MOVE SLOWLY ACROSS THE REGION BEGINNING ON
WEDNESDAY. STRONGEST UPPER LEVEL FORCING /Q-VECTOR CONVERGENCE AND
FGEN/ LOOKS TO REMAIN PRIMARILY NORTH OF THE AREA DURING THE DAY ON
WEDNESDAY...ALTHOUGH WILL MAINTAIN LOW POPS AS THERE IS SOME
UNCERTAINTY REGARDING TIMING OF PRECIPITATION. THE BRUNT OF
FORCING/SATURATION WILL AFFECT THE AREA ON WEDNESDAY NIGHT AND
EARLY THURSDAY DUE TO A COMBINATION OF UPPER LEVEL DIVERGENCE AND
A MODERATE MID-LEVEL FRONTOGENETIC ZONE. QPF AMOUNTS STILL A BIT
TRICKY TO PIN DOWN AT THIS TIMEFRAME...BUT MODEL CONSENSUS
INDICATES THAT 0.25"-0.50" IS POSSIBLE...WITH LOCALLY HIGHER
AMOUNTS. FROPA IS PROGGED TO BE A BIT QUICKER IN 12Z SUITE OF
MODELS...SO BEGAN TO TAPER PRECIP CHANCES SIGNIFICANTLY AFTER 18Z
THURSDAY. TEMPS SHOULD BE NEAR NORMAL WED...COOLING ON THURSDAY
BEHIND THE FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY...
SURFACE HIGH PRESSURE AND A COLD ARCTIC AIR AIRMASS WILL FILTER
INTO THE REGION LATE IN THE WEEK...RESULTING IN BELOW NORMAL
TEMPERATURES THROUGH THE REMAINDER OF THE LONG TERM PERIOD. ONLY
REAL CHANCES FOR PRECIPITATION WILL BE ASSOCIATED WITH ANOTHER
SERIES OF UPPER LEVEL DISTURBANCES WHICH WILL MOVE ACROSS THE
REGION OVER LATE THIS WEEKEND.
MF/KS
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1219 PM CDT MON OCT 22 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...SCT TO OCCASIONALLY BKN CLOUDS AT 2500 TO 3000 FT
SHOULD CONTINUE TO RISE TO ABOUT 3500 TO 4000 FT OVER THE NEXT
COUPLE OF HOURS LEADING TO VFR CIG/VISBY. SOUTH TO SOUTHEAST WINDS AT 15
TO 2O KTS WITH GUSTS 25 TO 28 KNOTS EXPECTED THROUGH ABOUT 6 TO 7 PM.
TONIGHT...WINDS SHOULD DIMINISH TO 6 TO 10 KNOTS BY EARLY EVENING
WITH CLEAR SKIES INITIALLY. INTERMITTENT CLOUD COVERAGE BETWEEN
2000 TO 3000 FT HAS JUST ENOUGH PROBABILITY TO GET SET UP TO
RESULT IN MVFR FORECAST FOR THE TAF SITES THROUGH THE LATE
NIGHT/EARLY MORNING. MEDIUM CONFIDENCE IN MVFR FOR THE TAF SITES
WITH FAIRLY HIGH CONFIDENCE IN MVFR NORTH OF EBG IN
ZAPATA...BROOKS...AND JIM HOGG COUNTIES. A FEW STREAMER SHOWERS
MAY WORK IN IN THE EARLY MORNING...ESPECIALLY NEAR THE COAST BUT
SHOULD NOT BE SIGNIFICANT OPERATIONAL IMPACT.
TUESDAY MORNING WINDS WILL RETURN OUT OF THE SOUTHEAST BUT GUSTS
SHOULD ONLY BE IN THE 15 T0 20 KNOT RANGE BY LATE MORNING. BRIEF
BOUTS OF SCT TO BKN AT 2500 FT OR SO WILL BE POSSIBLE WITH ANY
CLOUD BASES RISING ABOVE 3000 FT AT ALL SITES BY 11 AM OR SO.
PREVAILING CONDITIONS SHOULD BE VFR. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 1127 AM CDT MON OCT 22 2012/
DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.
MARINE...LATEST BUOY REPORT CONTINUES TO SHOW RISING SEA HEIGHTS
ALONG THE GULF WATERS. STEADY SOUTHEAST WINDS AROUND 20 KNOTS WILL
BEGIN TO DIMINISH SOMEWHAT BY MID AFTERNOON BUT ROUGH SEAS WILL
REMAIN A POSSIBILITY. WITH THE RECENT INCREASE IN WAVE HEIGHT
ABOVE WHAT HAD PREVIOUSLY BEEN EXPECTED HAVE ISSUED A SMALL CRAFT
ADVISORY THROUGH 6 PM TONIGHT FOR STRONG WINDS AND ROUGH SEAS FOR
THE GULF WATERS. THE ADVISORY FOR THE LAGUNA ALSO REMAINS IN EFFECT.
PREV DISCUSSION... /ISSUED 953 AM CDT MON OCT 22 2012/
DISCUSSION...MAIN PLAYERS IN THE WEATHER THIS MORNING ARE THE
ISOLATED SHOWERS OVER THE LAGUNA MADRE...AND WINDS WHICH HAVE
ALREADY STARTED OVER THE MARINE AREAS AND ARE BEGINNING TO
INCREASE OVER LAND. SURFACE AND UPPER AIR ANALYSIS...COMBINED WITH
WATER VAPOR SHOW AN UPPER LEVEL LOW ADVANCING INTO THE PANHANDLE
REGION OF TEXAS. THE SUBTROPICAL JET MAX TO THE SOUTH WILL HAVE
ITS RIGHT EXIT REGION OVER SOUTH TEXAS PUTTING US IN AN
INCREASINGLY CONVERGENT PATTERN ALOFT AND WEAKLY INCREASING MID
GULF RIDGING...AS THE JET MAX AND ASSOCIATED UPPER LOW HELP DEEPEN
TROUGHING OVER THE CENTRAL PLAINS AND IN THE LEE OF THE SIERRA
MADRE MOUNTAINS. SEQUENTIAL SFC ANALYSIS SHOWS OUR GRADIENT IS NOT
RELAXING VERY MUCH...BUT RUC13 AND NAM12 GUIDANCE AND LINEAR
EXTRAPOLATION OF THE INVOLVED FEATURES SHOWS IT SHOULD START TO
BACK OFF BY ABOUT 4 OR 5 PM TODAY.
THROUGH 700 PM TONIGHT...EXPECT A MARKED INCREASE IN SURFACE WIND
SPEED THROUGH 1100 AM AT ALL LOCATIONS WITH SUSTAINED WINDS 15 TO
20 MPH WITH GUSTS TO AROUND 30 MPH AT TIMES. DID ISSUE A SMALL
CRAFT ADVISORY FOR THE LAGUNA DUE TO OBS TRENDS AND THE FACT THAT
A SUBSTANTIAL CHANGE IN OUR SFC PRESSURE GRADIENT IS NOT EXPECTED
SOON. THE SHOWERS OVER THE LAGUNA SHOULD CONTINUE FOR ANOTHER
COUPLE OF HOURS BEFORE DRIER MID LEVEL AIR WORKS TO THE SURFACE
AND STABILIZES THE BOUNDARY LAYER. DID ADD A SCHC/ISO MENTION A
LITTLE FURTHER IN INTO KENEDY COUNTY WHERE THERE WILL BE SLIGHTLY
BETTER SFC CONVERGENCE AND THE LATEST SREF TRIES TO PAINT A LITTLE
PRECIP THIS AFTERNOON. PRECIP SHOULD BE VERY LIGHT AND LOW IMPACT.
TONIGHT WINDS SHOULD BEGIN TO GRADUALLY DIMINISH WITH A LITTLE BIT
OF MID AND LOW CLOUD POSSIBLE. NO CHANGES TO THESE GRIDS AT THIS
TIME. /68-JGG/
MARINE...ISSUED A SMALL CRAFT ADVISORY WITH MORNING MARINE UPDATE
DUE TO SUSTAINED WINDS PICKING UP AT TCOON/OBS SITES ALONG THE
LAGUNA. WINDS SHOULD NOT DIMINISH UNTIL MID TO LATE AFTERNOON AT
MOST LOCATIONS. EXPECT WINDS IN THE NEARSHORE WATERS...WHICH ARE
BORDERLINE ADVISORY LEVELS RIGHT NOW WILL DIMINISH AS THE HEATING
OF THE DAY CONTINUES SO KEPT THESE WATERS EXERCISE CAUTION FOR
NOW. /68-JGG/
PREV DISCUSSION... /ISSUED 621 AM CDT MON OCT 22 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE
PERIOD. WINDS WILL GRADUALLY INCREASE LATER THIS MORNING...GENERALLY
AFTER 14Z...TO BREEZY LEVELS AS HIGH PRESSURE OVER THE GULF OF
MEXICO INTERACTS WITH LOW PRESSURE OVER THE CENTRAL PLAINS.
SOUTHEAST WINDS WILL SLOWLY DECREASE MONDAY EVENING...AROUND 3Z.
PREV DISCUSSION... /ISSUED 440 AM CDT MON OCT 22 2012/
SHORT TERM /TODAY THROUGH TUESDAY/...SURFACE LOW PRESSURE OVER THE
CENTRAL PLAINS WILL MOVE NORTHEAST LATER TODAY. THIS WILL RESULT IN
A WEAKEN PRESSURE GRADIENT ACROSS DEEP SOUTH TEXAS THROUGH THE
FORECAST PERIOD. SURFACE HIGH PRESSURE ACROSS THE GULF OF MEXICO TO
THE MID ATLANTIC STATES WILL MAINTAIN LIGHT TO MODERATE SOUTHEAST
WINDS ACROSS THE AREA THROUGH TUESDAY. WILL MAINTAIN ISOLATED POPS
FOR TODAY AS LOW LEVEL MOISTURE /PWATS OF 1.40 INCHES/ AND LIFT
SHOULD PRODUCE SEA BREEZE CONVECTION LATER THIS MORNING INTO THE
AFTERNOON. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
TUESDAY AFTERNOON.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...500 MB RIDGING WILL
REMAIN ANCHORED IN PLACE OVER MEXICO AND THE SOUTHEASTERN UNITED
STATES THROUGH FRIDAY MAINTAINING GENERALLY HOT AND RAINFREE
CONDITIONS OVER DEEP SOUTH TX. A BROAD MID LEVEL TROUGH IS THEN
EXPECTED TO DIG ACROSS THE NORTH CENTRAL PORTIONS OF THE LOWER 48
STATES AFTER FRIDAY. AS THIS FEATURE DIGS IN...IT WILL PUSH A FAIRLY
STRONG COLD FRONT SOUTH INTO DEEP SOUTH TX SATURDAY MORNING. THIS
TROUGH AXIS IS EXPECTED TO START TO SHIFT FURTHER EAST AFTER THIS
WEEKEND ALLOWING FOR RIDGING TO BUILD EAST SLOWLY. SOME DECENT
MOISTURE VALUES POOL OVER DEEP SOUTH TX JUST AHEAD OF THE FRONT
AND WILL ACCORDINGLY INCLUDE A MENTION OF SLGT CHC POPS FROM FRI
THROUGH SUN. THE ECMWF WANTS TO DRY OUT THE MOISTURE LEVELS
QUICKER VERSUS THE GFS WITH THE GFS TRYING TO SPIN UP SOME COASTAL
SURFACE TROFFING WHICH MAY ENHANCE POPS LATER IN THE FORECAST
PERIOD. AM NOT READY TO GO MUCH HIGHER THAN 20 % POPS UNTIL BOTH
THE ECMWF AND GFS COME INTO BETTER AGREEMENT ON WHETHER OR NOT
THIS SURFACE TROFFING ACTUALLY FORMS OR NOT.
OTHER THAN THE DIFFERENCES ON THE COASTAL TROFFING..THE ECMWF AND
GFS ARE IN DECENT AGREEMENT ON THE TIMING AND STRENGTH OF THE
FROPA ON SATURDAY AND ARE ALSO IN AGREEMENT IN THE PLACEMENT AND
STRENGTH OF THE 500 MB FEATURES THROUGH NEXT WEEKEND. RUN TO RUN
CONSISTENCY WITH THE GFS MEX MOS TEMPS AND POPS IS PRETTY STABLE
THROUGH MON. WILL GO AT OR ABOVE THE MEX MOS TEMPS FOR THE DAYS
AHEAD OF THE FRONT AND WILL GO WITH A GFS AND ECMWF BLEND FOR SAT
AND SUN. PREFER THE GFS MEX MOS POPS THROUGH DAYS 7 AND 8.
OVERALL CONFIDENCE IN THE LONGER RANGE FORECAST WORDING AND
REASONING IS ABOVE AVERAGE.
MARINE /TODAY THROUGH TUESDAY/...CURRENTLY BUOY 42020 REPORTS A
SOUTHEAST WIND AROUND 18 KNOTS AND SEAS AT 4.3 FEET WITH A PERIOD
OF 6 SECONDS AT 250 AM CDT. BUOY 42020 AND THE TEXAS COASTAL OCEAN
OBSERVATION NETWORK (TCOON) PLATFORMS OVERNIGHT HAVE INDICATED
THAT SMALL CRAFT ADVISORY CONDITIONS ARE NOT OCCURRING AT THIS
TIME OVER THE GULF OF MEXICO WATERS EAST OF PADRE ISLAND FROM 0 TO
60 NAUTICAL MILES OFFSHORE. THEREFORE...THE SMALL CRAFT ADVISORY
THAT WAS IN EFFECT UNTIL 4 AM WILL BE ALLOWED TO EXPIRE.
INTERACTION BETWEEN THE HIGH OVER THE GULF AND LOW PRESSURE OVER
THE CENTRAL PLAINS SHOULD RESULT IN SMALL CRAFT EXERCISE CAUTION
CONDITIONS TODAY. MODERATE SOUTHEAST WINDS EXPECTED ON TUESDAY AS
WEAK HIGH PRESSURE PREVAILS OVER THE WESTERN GULF OF MEXICO.
TUESDAY NIGHT THROUGH FRIDAY...SURFACE RIDGING WILL REMAIN
IN PLACE OVER THE EASTERN STATES AND THE GULF OF MEXICO WHICH
WILL MAINTAIN A MODERATE TO STRONG ONSHORE SURFACE FLOW IN PLACE
OVER THE LOWER TX BAY AND GULF WATERS THROUGH THE END OF THE WEEK.
THIS WILL LIKELY MAINTAIN THE BAY WATERS AND GULF SEAS CLOSE TO
SCEC OR SCA LEVELS THROUGH FRI. MEANWHILE IN THE CENTRAL CARIB...
NHC CONTINUES TO MONITOR A LARGE LOW PRESSURE FOR SOME POSSIBLE
DEVELOPMENT. THE GFS/ECMWF AND CMC GUIDANCE ALL TAKE THIS FEATURE
IS A GENERAL NORTHEASTERLY DIRECTION THROUGHOUT THE UPCOMING WEEK
WHICH SHOULD KEEP THIS FEATURE OUT OF THE GULF OF MEX MOVING UP
INTO THE WESTERN ATLANTIC. PLEASE REFER TO THE LATEST TROPICAL
WEATHER OUTLOOK FROM NHC CONCERNING THIS FEATURE.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CDT THIS EVENING FOR
GMZ130-132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR GMZ150-155-
170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/67
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1127 AM CDT MON OCT 22 2012
.DISCUSSION...UPDATED FOR LATEST MARINE DISCUSSION BELOW.
&&
.MARINE...LATEST BUOY REPORT CONTINUES TO SHOW RISING SEA HEIGHTS
ALONG THE GULF WATERS. STEADY SOUTHEAST WINDS AROUND 20 KNOTS WILL
BEGIN TO DIMINISH SOMEWHAT BY MID AFTERNOON BUT ROUGH SEAS WILL
REMAIN A POSSIBILITY. WITH THE RECENT INCREASE IN WAVE HEIGHT
ABOVE WHAT HAD PREVIOUSLY BEEN EXPECTED HAVE ISSUED A SMALL CRAFT
ADVISORY THROUGH 6 PM TONIGHT FOR STRONG WINDS AND ROUGH SEAS FOR
THE GULF WATERS. THE ADVISORY FOR THE LAGUNA ALSO REMAINS IN EFFECT.
&&
.PREV DISCUSSION... /ISSUED 953 AM CDT MON OCT 22 2012/
DISCUSSION...MAIN PLAYERS IN THE WEATHER THIS MORNING ARE THE
ISOLATED SHOWERS OVER THE LAGUNA MADRE...AND WINDS WHICH HAVE
ALREADY STARTED OVER THE MARINE AREAS AND ARE BEGINNING TO
INCREASE OVER LAND. SURFACE AND UPPER AIR ANALYSIS...COMBINED WITH
WATER VAPOR SHOW AN UPPER LEVEL LOW ADVANCING INTO THE PANHANDLE
REGION OF TEXAS. THE SUBTROPICAL JET MAX TO THE SOUTH WILL HAVE
ITS RIGHT EXIT REGION OVER SOUTH TEXAS PUTTING US IN AN
INCREASINGLY CONVERGENT PATTERN ALOFT AND WEAKLY INCREASING MID
GULF RIDGING...AS THE JET MAX AND ASSOCIATED UPPER LOW HELP DEEPEN
TROUGHING OVER THE CENTRAL PLAINS AND IN THE LEE OF THE SIERRA
MADRE MOUNTAINS. SEQUENTIAL SFC ANALYSIS SHOWS OUR GRADIENT IS NOT
RELAXING VERY MUCH...BUT RUC13 AND NAM12 GUIDANCE AND LINEAR
EXTRAPOLATION OF THE INVOLVED FEATURES SHOWS IT SHOULD START TO
BACK OFF BY ABOUT 4 OR 5 PM TODAY.
THROUGH 700 PM TONIGHT...EXPECT A MARKED INCREASE IN SURFACE WIND
SPEED THROUGH 1100 AM AT ALL LOCATIONS WITH SUSTAINED WINDS 15 TO
20 MPH WITH GUSTS TO AROUND 30 MPH AT TIMES. DID ISSUE A SMALL
CRAFT ADVISORY FOR THE LAGUNA DUE TO OBS TRENDS AND THE FACT THAT
A SUBSTANTIAL CHANGE IN OUR SFC PRESSURE GRADIENT IS NOT EXPECTED
SOON. THE SHOWERS OVER THE LAGUNA SHOULD CONTINUE FOR ANOTHER
COUPLE OF HOURS BEFORE DRIER MID LEVEL AIR WORKS TO THE SURFACE
AND STABILIZES THE BOUNDARY LAYER. DID ADD A SCHC/ISO MENTION A
LITTLE FURTHER IN INTO KENEDY COUNTY WHERE THERE WILL BE SLIGHTLY
BETTER SFC CONVERGENCE AND THE LATEST SREF TRIES TO PAINT A LITTLE
PRECIP THIS AFTERNOON. PRECIP SHOULD BE VERY LIGHT AND LOW IMPACT.
TONIGHT WINDS SHOULD BEGIN TO GRADUALLY DIMINISH WITH A LITTLE BIT
OF MID AND LOW CLOUD POSSIBLE. NO CHANGES TO THESE GRIDS AT THIS
TIME. /68-JGG/
MARINE...ISSUED A SMALL CRAFT ADVISORY WITH MORNING MARINE UPDATE
DUE TO SUSTAINED WINDS PICKING UP AT TCOON/OBS SITES ALONG THE
LAGUNA. WINDS SHOULD NOT DIMINISH UNTIL MID TO LATE AFTERNOON AT
MOST LOCATIONS. EXPECT WINDS IN THE NEARSHORE WATERS...WHICH ARE
BORDERLINE ADVISORY LEVELS RIGHT NOW WILL DIMINISH AS THE HEATING
OF THE DAY CONTINUES SO KEPT THESE WATERS EXERCISE CAUTION FOR
NOW. /68-JGG/
PREV DISCUSSION... /ISSUED 621 AM CDT MON OCT 22 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE
PERIOD. WINDS WILL GRADUALLY INCREASE LATER THIS MORNING...GENERALLY
AFTER 14Z...TO BREEZY LEVELS AS HIGH PRESSURE OVER THE GULF OF
MEXICO INTERACTS WITH LOW PRESSURE OVER THE CENTRAL PLAINS.
SOUTHEAST WINDS WILL SLOWLY DECREASE MONDAY EVENING...AROUND 3Z.
PREV DISCUSSION... /ISSUED 440 AM CDT MON OCT 22 2012/
SHORT TERM /TODAY THROUGH TUESDAY/...SURFACE LOW PRESSURE OVER THE
CENTRAL PLAINS WILL MOVE NORTHEAST LATER TODAY. THIS WILL RESULT IN
A WEAKEN PRESSURE GRADIENT ACROSS DEEP SOUTH TEXAS THROUGH THE
FORECAST PERIOD. SURFACE HIGH PRESSURE ACROSS THE GULF OF MEXICO TO
THE MID ATLANTIC STATES WILL MAINTAIN LIGHT TO MODERATE SOUTHEAST
WINDS ACROSS THE AREA THROUGH TUESDAY. WILL MAINTAIN ISOLATED POPS
FOR TODAY AS LOW LEVEL MOISTURE /PWATS OF 1.40 INCHES/ AND LIFT
SHOULD PRODUCE SEA BREEZE CONVECTION LATER THIS MORNING INTO THE
AFTERNOON. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
TUESDAY AFTERNOON.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...500 MB RIDGING WILL
REMAIN ANCHORED IN PLACE OVER MEXICO AND THE SOUTHEASTERN UNITED
STATES THROUGH FRIDAY MAINTAINING GENERALLY HOT AND RAINFREE
CONDITIONS OVER DEEP SOUTH TX. A BROAD MID LEVEL TROUGH IS THEN
EXPECTED TO DIG ACROSS THE NORTH CENTRAL PORTIONS OF THE LOWER 48
STATES AFTER FRIDAY. AS THIS FEATURE DIGS IN...IT WILL PUSH A FAIRLY
STRONG COLD FRONT SOUTH INTO DEEP SOUTH TX SATURDAY MORNING. THIS
TROUGH AXIS IS EXPECTED TO START TO SHIFT FURTHER EAST AFTER THIS
WEEKEND ALLOWING FOR RIDGING TO BUILD EAST SLOWLY. SOME DECENT
MOISTURE VALUES POOL OVER DEEP SOUTH TX JUST AHEAD OF THE FRONT
AND WILL ACCORDINGLY INCLUDE A MENTION OF SLGT CHC POPS FROM FRI
THROUGH SUN. THE ECMWF WANTS TO DRY OUT THE MOISTURE LEVELS
QUICKER VERSUS THE GFS WITH THE GFS TRYING TO SPIN UP SOME COASTAL
SURFACE TROFFING WHICH MAY ENHANCE POPS LATER IN THE FORECAST
PERIOD. AM NOT READY TO GO MUCH HIGHER THAN 20 % POPS UNTIL BOTH
THE ECMWF AND GFS COME INTO BETTER AGREEMENT ON WHETHER OR NOT
THIS SURFACE TROFFING ACTUALLY FORMS OR NOT.
OTHER THAN THE DIFFERENCES ON THE COASTAL TROFFING..THE ECMWF AND
GFS ARE IN DECENT AGREEMENT ON THE TIMING AND STRENGTH OF THE
FROPA ON SATURDAY AND ARE ALSO IN AGREEMENT IN THE PLACEMENT AND
STRENGTH OF THE 500 MB FEATURES THROUGH NEXT WEEKEND. RUN TO RUN
CONSISTENCY WITH THE GFS MEX MOS TEMPS AND POPS IS PRETTY STABLE
THROUGH MON. WILL GO AT OR ABOVE THE MEX MOS TEMPS FOR THE DAYS
AHEAD OF THE FRONT AND WILL GO WITH A GFS AND ECMWF BLEND FOR SAT
AND SUN. PREFER THE GFS MEX MOS POPS THROUGH DAYS 7 AND 8.
OVERALL CONFIDENCE IN THE LONGER RANGE FORECAST WORDING AND
REASONING IS ABOVE AVERAGE.
MARINE /TODAY THROUGH TUESDAY/...CURRENTLY BUOY 42020 REPORTS A
SOUTHEAST WIND AROUND 18 KNOTS AND SEAS AT 4.3 FEET WITH A PERIOD
OF 6 SECONDS AT 250 AM CDT. BUOY 42020 AND THE TEXAS COASTAL OCEAN
OBSERVATION NETWORK (TCOON) PLATFORMS OVERNIGHT HAVE INDICATED
THAT SMALL CRAFT ADVISORY CONDITIONS ARE NOT OCCURRING AT THIS
TIME OVER THE GULF OF MEXICO WATERS EAST OF PADRE ISLAND FROM 0 TO
60 NAUTICAL MILES OFFSHORE. THEREFORE...THE SMALL CRAFT ADVISORY
THAT WAS IN EFFECT UNTIL 4 AM WILL BE ALLOWED TO EXPIRE.
INTERACTION BETWEEN THE HIGH OVER THE GULF AND LOW PRESSURE OVER
THE CENTRAL PLAINS SHOULD RESULT IN SMALL CRAFT EXERCISE CAUTION
CONDITIONS TODAY. MODERATE SOUTHEAST WINDS EXPECTED ON TUESDAY AS
WEAK HIGH PRESSURE PREVAILS OVER THE WESTERN GULF OF MEXICO.
TUESDAY NIGHT THROUGH FRIDAY...SURFACE RIDGING WILL REMAIN
IN PLACE OVER THE EASTERN STATES AND THE GULF OF MEXICO WHICH
WILL MAINTAIN A MODERATE TO STRONG ONSHORE SURFACE FLOW IN PLACE
OVER THE LOWER TX BAY AND GULF WATERS THROUGH THE END OF THE WEEK.
THIS WILL LIKELY MAINTAIN THE BAY WATERS AND GULF SEAS CLOSE TO
SCEC OR SCA LEVELS THROUGH FRI. MEANWHILE IN THE CENTRAL CARIB...
NHC CONTINUES TO MONITOR A LARGE LOW PRESSURE FOR SOME POSSIBLE
DEVELOPMENT. THE GFS/ECMWF AND CMC GUIDANCE ALL TAKE THIS FEATURE
IS A GENERAL NORTHEASTERLY DIRECTION THROUGHOUT THE UPCOMING WEEK
WHICH SHOULD KEEP THIS FEATURE OUT OF THE GULF OF MEX MOVING UP
INTO THE WESTERN ATLANTIC. PLEASE REFER TO THE LATEST TROPICAL
WEATHER OUTLOOK FROM NHC CONCERNING THIS FEATURE.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CDT THIS EVENING FOR
GMZ130-132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR GMZ150-155-
170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/67
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1145 PM CDT SAT OCT 20 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
319 PM CDT SAT OCT 20 2012
THE MAIN CHALLENGES THROUGH EARLY NEXT WEEK REST WITH WHETHER THE
STRATUS/FOG WILL REDEVELOP TONIGHT...THE RAIN/THUNDER CHANCES
SUNDAY NIGHT THROUGH TUESDAY...AND TEMPERATURES AS A COLD FRONT
STALLS ACROSS THE REGION.
FIRST...TWO BANDS OF STRATUS AND FOG LINGERED THROUGH THIS MORNING
WITH ONE BAND ASSOCIATED WITH AN INVERTED SURFACE TROUGH IN
NORTHEAST WISCONSIN AND A SECOND BAND ASSOCIATED WITH WEAK
925/850MB CONVERGENCE ABOVE A SURFACE RIDGE ALONG AND WEST OF THE
MISSISSIPPI RIVER. DIURNAL HEATING AND MIXING HAS ERODED THE EDGES
OF THESE BANDS AND CONVERTED THE STRATUS INTO A CUMULUS
FIELD...BUT THE QUESTION REMAINS WITH WHETHER THIS STRATUS
REDEVELOPS OVERNIGHT AGAIN. THE RAP HAS DONE THE BEST WITH SHOWING
THIS LOW LEVEL MOISTURE BEING TRAPPED UNDER AN INVERSION AROUND
900MB THAT STRENGTHENS TONIGHT AS LOW LEVEL WARM AIR ADVECTION
KICKS IN. THE WESTERN EDGE OF THE STRATUS/FOG FIELD ACROSS
MINNESOTA AND IOWA APPEARS TO ALSO BE TIED TO THE 925/850MB
TEMPERATURE GRADIENT WHERE LOW LEVEL WINDS COME AROUND TO THE
WEST-SOUTHWEST. THE 20.12Z NAM/GFS/RAP SLOWLY BRINGS THIS LOW
LEVEL TEMPERATURE GRADIENT THROUGH THE REGION OVERNIGHT...BUT WITH
THE SURFACE RIDGE STILL OVERHEAD AND A SHALLOW INVERSION IN PLACE
IT APPEARS THAT SOME STRATUS OR FOG WILL AGAIN DEVELOP TONIGHT.
CONFIDENCE IS NOT HIGH ENOUGH AT THIS POINT TO PUT DENSE FOG IN
THE FORECAST...BUT IT IS A POSSIBILITY...PARTICULARLY ACROSS
WESTERN WISCONSIN.
WINDS FROM THE SURFACE ON UP WILL BE OUT OF THE SOUTH TOMORROW AS
A WARMER AIR MASS MOVES INTO THE REGION. THE NEXT CHANCES FOR
PRECIPITATION WILL COME IN TOMORROW NIGHT AS A CUT OFF MID LEVEL LOW
CURRENTLY OFF THE BAJA OF CALIFORNIA GETS CAUGHT IN THE
SOUTHWESTERLY FLOW ALOFT AND QUICKLY TRACKS ACROSS THE SOUTHERN
PLAINS AND INTO THE MID TO UPPER MISSISSIPPI RIVER VALLEY REGION
BY EARLY MONDAY. THIS FEATURE WILL HELP TO BRING A SURFACE LOW
PRESSURE SYSTEM UP ALONG A STALLING OUT COLD FRONT TOMORROW NIGHT
INTO MONDAY WHICH WILL INCREASE THE LOW LEVEL MOISTURE TRANSPORT
OUT OF THE GULF OVER THIS PERIOD. BASED ON 20.12Z NAM/GFS BUFKIT
SOUNDINGS...THERE DOES APPEAR TO BE SOME ELEVATED INSTABILITY THAT
DEVELOPS EARLY MONDAY WITH 0-3KM MUCAPE CLIMBING UP TO AROUND 1000
J/KG. A VEERING WIND PROFILE WITH HEIGHT MAY PROVIDE ENOUGH WIND
SHEAR FOR A FEW ISOLATED HAILERS TO FORM AS WELL.
THIS COLD FRONT WILL THEN BECOME STATIONARY ON MONDAY AS ANOTHER
SURFACE LOW DEVELOPS ALONG THE SOUTHERN PERIPHERY OF IT IN THE
CENTRAL PLAINS. THE 20.12Z GFS/ECMWF ARE MORE ROBUST WITH QPF
THROUGH THE DAY ON MONDAY COMPARED TO THE NAM WITH THE HIGHER
PROBABILITIES OF RAIN ACROSS SOUTHERN WISCONSIN. WITH
SOUTHWESTERLY FLOW ALOFT...ANOTHER LOW WILL TRACK ACROSS MONTANA
AND HELP TO BRING THE WARM AIR MASS IN PLACE THROUGH THE PLAINS
FURTHER NORTH ACROSS THE REGION. WITH SOME INSTABILITY LINGERING
ALONG THE FRONT...CAN NOT RULE OUT SOME SHOWERS/THUNDERSTORMS
MONDAY NIGHT INTO TUESDAY AS THE FRONT KICKS BACK TO THE NORTH AS
A WARM FRONT. DEW POINTS SOUTH OF THE FRONT LOOK TO BE FAIRLY
HUMID FOR THIS TIME OF YEAR WITH THEM CLIMBING INTO THE 50S
TOMORROW NIGHT AND THEN INTO THE 60S BY TUESDAY. CONFIDENCE IS NOT
HIGH WITH THE EXACT TIMING AND INTENSITY OF THE SHOWERS/STORMS
GOING FROM MONDAY NIGHT INTO TUESDAY...BUT THERE SHOULD BE BREAKS
IN THE ROUNDS OF SHOWERS/STORMS.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
319 PM CDT SAT OCT 20 2012
WARM AIR WILL REMAIN ACROSS THE REGION WITH SOUTHWESTERLY LOW TO
UPPER LEVEL FLOW IN PLACE THROUGH MUCH OF THE CENTRAL US INTO THE
GREAT LAKES. AS THE SURFACE WARM FRONT LIFTS NORTH TUESDAY NIGHT
INTO WEDNESDAY...THE NEXT LOW PRESSURE SYSTEM WILL DEVELOP IN THE
CENTRAL PLAINS AND TRACK THROUGH THE UPPER GREAT LAKES REGION BY
WEDNESDAY NIGHT. THIS WILL HELP TO BRING A COLD FRONT THROUGH
WEDNESDAY INTO WEDNESDAY NIGHT WITH SHOWERS/THUNDERSTORMS
DEVELOPING ALONG IT. THE 20.12Z ECMWF/GEM IS THE PREFERRED
SOLUTION WITH A QUICKER TREND OF BRINGING THE COLD FRONT THROUGH
COMPARED TO THE 20.12Z GFS WHICH WAITS UNTIL THURSDAY TO BRING IT
THROUGH. HAVE KEPT SOME CHANCES IN THERE FOR THURSDAY TO ACCOUNT
FOR THE GFS SOLUTION...BUT IF IT STARTS TO TREND TOWARD THE OTHER
GUIDANCE IT MAY END UP DRY THAT DAY.
THE NEXT FEATURE TO WATCH IS WITH NEXT FRIDAY AND WHICH WAY THE
MODELS TREND WITH ANOTHER SYSTEM THAT LIFTS OUT OF THE SOUTHERN
PLAINS. MUCH OF THE PREVIOUS GUIDANCE HAS KEPT THIS SYSTEM WELL TO
THE SOUTHEAST AND NOT AFFECTING THE REGION...THOUGH THE 20.12Z
ECMWF CAME IN WITH A SOLUTION FURTHER TO THE NORTHWEST. THIS WOULD
PRODUCE A LENGTHY BAND OF PRECIPITATION FROM THE SOUTHERN PLAINS
INTO THE WESTERN GREAT LAKES WITH THE WESTERN EDGE OF IT COVERING
THE FORECAST AREA. SURFACE WET BULB TEMPERATURES AND THE
TEMPERATURE PROFILE ABOVE THE GROUND LOOK WARM ENOUGH FOR THE
P-TYPE TO BE ALL LIQUID...BUT IT WILL BE CLOSE TO FREEZING AND
WILL HAVE TO BE MONITORED OVER THE NEXT WEEK.
&&
.AVIATION...THROUGH 06Z MONDAY
1144 PM CDT SAT OCT 20 2012
LOW CLOUDS ARE NO LONGER A CONCERN AS THE PATCH OF CLOUDS IN THE
I35 CORRIDOR HAS DISSIPATED THIS EVENING. STILL SOME CONCERN FOR
FOG OVERNIGHT BUT IF IT DOES FORM...IT WILL NOT BE UNTIL LATE
AFTER A BAND OF HIGH CLOUDS CLEARS THE AREA. HAVE TIMED THESE
CLOUDS PAST THE TAF SITES BETWEEN 08 AND 10Z SO WOULD EXPECT ANY
FOG THAT FORMS TO WAIT AN HOUR OR TWO AFTER THESE CLOUDS CLEAR
OUT. THEN THERE IS STILL THE ISSUE OF THE STRONGER WINDS ALOFT AND
IF THESE WILL CREATE TOO MUCH TURBULENT MIXING AT THE INVERSION
LEVEL TO ALLOW THE FOG TO FORM. THE 21.00Z NAM STILL SHOWS WINDS
OF 20 TO 25 KNOTS FROM ABOUT 950 MB AND ABOVE. LATEST VWP WINDS
FROM KDMX AND KMPX CONTINUE TO VERIFY THESE WINDS WITH SPEEDS OF
15 AND 20 KNOTS RESPECTIVELY AT 950 MB SO WILL LIMIT ANY
VISIBILITY REDUCTION FROM FOG TO 4 MILES AT KLSE AND 2 MILES AT
KRST. ONCE THE FOG THREAT IS OVER SUNDAY MORNING...THE REST OF THE
PERIOD LOOKS TO HAVE VFR CONDITIONS WITH INCREASING SOUTH WINDS
AND SOME GUSTS AT KRST DURING THE AFTERNOON. AN APPROACHING SYSTEM
FROM THE SOUTHWEST WILL BRING CEILINGS DOWN WITH A THREAT FOR RAIN
BUT THIS WILL NOT BE UNTIL AFTER 06Z MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
319 PM CDT SAT OCT 20 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
454 AM EDT TUE OCT 23 2012
.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTHWEST TODAY AND
TONIGHT...AS A WEAK WAVE OF LOW PRESSURE TRAVELS ALONG IT. THIS WILL
BRING CLOUDS AND SOME RAIN TO THE REGION THROUGH WEDNESDAY
MORNING...WITH THE BEST CHANCE OF RAIN EXPECTED FROM THE GREATER
CAPITAL REGION AND AREAS SOUTH AND WEST. TEMPERATURES WILL REMAIN
SOMEWHAT COOL DUE TO CLOUDS AND RAIN THROUGH WEDNESDAY...BEFORE
GRADUALLY WARMING FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 445 AM EDT...HIGH CLOUDS ARE GRADUALLY INCREASING ACROSS THE
REGION...WITH MID LEVEL CLOUDS SLOWLY APPROACHING FROM THE WEST.
TEMPS HAVE DROPPED INTO THE UPPER 30S TO LOWER 40S IN MOST
VALLEYS...WITH MID 30S ACROSS PORTIONS OF THE SOUTHERN ADIRONDACKS.
CLOUDS WILL CONTINUE TO INCREASE/THICKEN FROM W TO E THROUGH MID
MORNING. SOME SUNSHINE MAY BE DIMLY VISIBLE AT TIMES UNTIL
THEN...ESP FOR AREAS E OF THE HUDSON RIVER VALLEY...AND INTO
SOUTHERN VT.
AS ONE SHORTWAVE...CURRENTLY OVER LOWER MICHIGAN...TRANSLATES
EASTWARD TODAY...INCREASING ISENTROPIC LIFT TO THE EAST OF THIS
FEATURE SHOULD ALLOW RAIN TO EXPAND INTO WESTERN AND SOUTHERN
PORTIONS OF THE REGION BY MID TO LATE MORNING. 00Z/23 MODELS AND
03Z/SREFS HAVE TRENDED FURTHER NORTH WITH THE EXPECTED RAIN SHIELD
WITH THIS SYSTEM...AND THIS IS FURTHER SUPPORTED BY RECENT
UPSTREAM RADAR TRENDS...AS WELL AS THE LATEST HRRR MODEL.
THEREFORE...HAVE RAISED POPS INTO THE LIKELY RANGE FOR CENTRAL AND
SOUTHERN PORTIONS OF THE REGION...FOR THIS
AFTERNOON/EVENING...WITH THE NORTHERN EDGE OF LIKELY POPS JUST N
OF SARATOGA...AND INTO EXTREME SW VT. IT IS POSSIBLE THAT THIS
INITIAL SURGE OF RAINFALL WEAKENS A BIT UPON MOVING FURTHER E INTO
OUR REGION...AS IT OUTRUNS THE BEST LOW LEVEL MOISTURE TRANSPORT
CURRENTLY FEEDING INTO IT FROM THE OHIO VALLEY REGION.
HOWEVER...RENEWED SHOWERS/RAIN WILL LIKELY DEVELOP ON THE
NORTHERN PERIPHERY OF THE SHORTWAVE AS IT TRANSLATES NEAR OR JUST
S/W OF THE CAPITAL REGION LATER THIS AFTERNOON OR EARLY THIS
EVENING.
RAINFALL AMTS SHOULD BE GENERALLY LIGHT TO MODERATE...WITH AN AREA
OF ONE QUARTER...TO ONE HALF INCH EXPECTED JUST S/W OF THE CAPITAL
REGION...ACROSS THE SCHOHARIE VALLEY AND CATSKILLS. SOMEWHAT
HIGHER AMTS ARE POSSIBLE WITHIN ANY EMBEDDED BANDS THAT
DEVELOP...AS MID LEVEL FRONTOGENETICAL FORCING INCREASES LATER
THIS AFTERNOON.
SOME WEAK ELEVATED INSTABILITY WILL PASS ACROSS SOUTHERN AREAS
LATER THIS AFTERNOON...WHICH COULD SUPPORT A FEW RUMBLES OF
THUNDER. HOWEVER...OVERALL ELEVATED INSTABILITY LOOKS MUCH WEAKER
THAN WHAT OCCURRED UPSTREAM DURING THE OVERNIGHT HOURS WHERE SOME
CG LIGHTNING STRIKES WERE NOTED. SO...HAVE KEPT OUT MENTION OF
THUNDER AT THIS TIME.
FOR TEMPS...GIVEN THE EXPECTED INCREASE IN CLOUD COVER AND
EVENTUAL RAIN...HAVE SIDED CLOSER TO THE COOLER MET MOS IN MOST
AREAS...WITH MID TO UPPER 50S EXPECTED FOR MAX TEMPS. GIVEN
INITIAL DEWPOINTS IN THE LOWER 40S...WET BULB COOLING MAY ACTUALLY
ALLOW TEMPS TO FALL ONCE THE RAIN DEVELOPS LATER THIS MORNING INTO
THE AFTERNOON. SHOULD THE RAIN DEVELOP ANY SOONER...EVEN COOLER
MAX TEMPS WOULD BE POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
TONIGHT...THE FIRST SHORTWAVE SHOULD TRANSLATE E/SE ACROSS THE
SOUTHERN HALF OF THE REGION THIS EVENING. THEN...A SECOND
SHORTWAVE SHOULD APPROACH SOUTHERN AREAS CLOSER TO DAYBREAK. THIS
SHOULD FAVOR SOUTHERN AREAS FOR THE BEST CHC FOR RAIN
OVERNIGHT...AFTER THE INITIAL SURGE OF LIGHT TO MODERATE RAINFALL
THIS EVENING. THEREFORE...WILL TREND LIKELY POPS SOUTHWARD THROUGH THE
EVENING AND OVERNIGHT HOURS. NORTHERN AREAS MAY ACTUALLY HAVE SOME
THIN SPOTS IN THE CLOUDS DEVELOP AT TIMES OVERNIGHT...WHICH COULD
ALLOW FOR COOLER TEMPS...AND SOME PATCHY FOG. HAVE GENERALLY SIDED
WITH A MAV/MET MOS BLEND...WHICH WERE FAIRLY CLOSE IN MOST AREAS.
WED-WED NT...MAIN FORCING MECHANISMS FOR LIFT SHOULD MOVE S AND E
OF REGION WED MORNING. IN THEIR WAKE...VERY LITTLE IN THE WAY OF
DYNAMICS WILL REMAIN. HOWEVER...LOW LEVEL MOISTURE AND WEAK LOW
LEVEL ISENTROPIC LIFT SHOULD PERSIST...AND MAY ACTUALLY INTENSIFY
WED NT. THEREFORE...WILL KEEP SOME SLIGHT CHC POPS FOR WED
AFTERNOON ACROSS SOUTHERN AREAS...THEN EXPAND POPS NORTHWARD...AND
INCLUDE CHC POPS ACROSS THE EASTERN CATSKILLS. THIS WILL BE FOR
LIGHT RAIN SHOWERS AND AREAS OF DRIZZLE IN THE PERSISTENT LOW
LEVEL ISENTROPIC LIFT...AND WELL AS FOR THE INTERACTION OF THE
HIGHER TERRAIN WITH THE MOIST AND LIGHT SE FLOW. FOR TEMPS...SIDED
CLOSER TO THE COOLER MET MOS AGAIN FOR WED...WITH MAINLY 55-60
EXPECTED IN MOST AREAS DUE TO CLOUDS AND SOME LIGHT RAIN/DRIZZLE.
FOR WED NT...SIDED CLOSER TO THE WARMER MET MOS...DUE TO EXPECTED
CLOUD COVER...WITH WIDESPREAD 40S TO LOWER 50S.
THU-THU NT...DESPITE STRONGLY RISING MID AND UPPER TROPOSPHERIC
HEIGHTS...A PERSISTENT MOIST SE FLOW MAY ACT TO KEEP LOW CLOUDS
AND SOME SPOTTY DRIZZLE FAIRLY PERSISTENT THROUGH THIS PERIOD. HAVE
THEREFORE SIDED CLOSER TO THE COOLER MET MOS...WITH GENERALLY
60-65 EXPECTED FOR MAXES...AND 40S TO LOWER 50S FOR MINS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
NOT A WHOLE LOT OF CHANGE TO THE LONG RANGE FORECAST WITH LOTS OF
SPREAD IN THE GUIDANCE AS TO HOW A POTENTIAL STORM ALONG THE EAST
COAST OF THE U.S EVOLVES. THE FIRST PART OF THE LONG RANGE
FORECAST...FRIDAY AND SATURDAY...LOOKS QUIET...WITH DRY WEATHER...
INCREASING CLOUD COVER AND HIGH TEMPERATURES IN THE 60S TO AROUND
70.
THERE COULD BE SOME ISOLATED SHOWERS ADVANCING INTO WESTERN
AREAS SATURDAY AFTERNOON DEPENDING ON THE TIMING OF THE APPROACH OF
A STRONG NORTHERN STREAM SYSTEM FROM THE MIDWEST AND GREAT LAKES.
THIS NORTHERN STREAM SYSTEM...COMBINED WITH HIGH AMPLITUDE UPPER
RIDGING JUST OFF THE CANADIAN COAST...IS PREDICTED TO INFLUENCE THE
MOVEMENT OF THE TROPICAL SYSTEM CURRENTLY DEVELOPING IN THE
CARIBBEAN.
DECENT CONSENSUS THAT THESE UPPER FEATURES WILL INTERACT WITH THE
TROPICAL SYSTEM...SUPPORTING NORTHWARD MOVEMENT. HOWEVER...THE EXACT
POSITION OF THESE STEERING FEATURES WILL DETERMINE WHETHER THE STORM
IMPACTS THE EASTERN U.S. OR STAYS MAINLY OUT TO SEA. SO...THE RANGE
OF POSSIBLE IMPACTS IS STILL ANYWHERE FROM NO IMPACT TO A
SIGNIFICANT IMPACT...BUT AN EXTREMELY UNUSUAL UPPER PATTERN
CONFIGURATION AND STORM TRACK WOULD BE REQUIRED FOR THE WORST CASE
SCENARIO OF HEAVY RAIN AND WINDS IN EASTERN AND NORTHERN NY AND
WESTERN NEW ENGLAND. STILL AT THE WAIT AND SEE STAGE FOR THIS
POTENTIAL SYSTEM...WHICH AGAIN COULD HAVE MINIMAL IMPACT OR
SIGNIFICANT IMPACT OR SOMETHING IN BETWEEN.
EVEN THE GUIDANCE THAT KEEPS THE STORM WELL OFFSHORE SHOWS OUR
REGION IN THE RIGHT ENTRANCE REGION OF A STRONG UPPER JET SEGMENT
AND DECENT BOUNDARY LAYER THERMAL GRADIENT ALONG A COLD FRONT...
ASSOCIATED WITH THE ADVANCING NORTHERN STREAM SYSTEM THAT COULD BE
GOING NEGATIVE TILT AND TRENDING TOWARD BECOMING A CUT OFF UPPER
LOW. SO EVEN IF WE DO NOT SEE A DIRECT IMPACT FROM THE STORM...SOME
ENHANCED RAINFALL ALONG THE COLD FRONT...AND WITHIN THE REGION OF
STRONG UPPER DYNAMICS...COULD OCCUR SATURDAY NIGHT THROUGH MONDAY.
JUST INDICATING CLOUDY WITH CHANCES OF RAIN SATURDAY NIGHT THROUGH
MONDAY WITH HIGHS IN THE MID 50S TO LOWER 60S SUNDAY AND UPPER 40S
TO MID 50S MONDAY.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
SOME HIGH THIN CLOUDS ARE SPREADING ACROSS THE REGION AHEAD OF AN
UPPER LEVEL SYSTEM IN THE GREAT LAKES AND VFR CONDITIONS SHOULD
PREVAIL THROUGH THIS MORNING. THE SYSTEM IN THE GREAT LAKES
SHOULD TRACK ACROSS OUR REGION THROUGH THE DAY AND EVENING. AN
AREA OF LIGHT RAIN SHOULD TRACK ACROSS CENTRAL AND SOUTHERN AREAS
FROM ABOUT 17Z THROUGH ABOUT 01Z. THE NORTHERN PERIPHERY OF THE
STEADIER RAIN SHOULD BE ABOUT KALB AND KPSF. HOWEVER...PUTTING
VCSH IN KGFL. SOME TEMPO MVFR CEILINGS AND VISIBILITIES ARE
POSSIBLE DURING THE RAIN AT KALB...KPSF ANDK POU THIS AFTERNOON
ADN EARLY EVENING. THE EXACT END OF THE RAIN IS UNKNOWN BUT KEPT
VCSH THROUGH 06Z AT ALL SITES UNTIL THE EXACT TIMING OF THE EXIT
OF THE RAIN IS KNOWN.
WINDS SHOULD BE LIGHT EAST TO NORTHEAST AT 5 KT OR LESS TROUGH THE
TAF PERIOD ENDING AT 06Z TOMORROW.
OUTLOOK...
TUE...MAINLY VFR. CHANCES -SHRA INCREASING AS THE DAY PROGRESSES
WITH THE BEST CHANCE AT KPOU.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA ESPECIALLY SOUTH OF KALB.
THU-FRI...VFR. NO SIG WX.
SAT...VFR. SLGT CHC -SHRA.
&&
.FIRE WEATHER...
FIRE WEATHER RELATED CONCERNS SHOULD REMAIN MINIMAL OVER THE NEXT
3 DAYS DUE TO LIGHT WINDS AND PERSISTENT HIGH RELATIVE
HUMIDITIES. REFER TO LATEST FWFALY FOR MORE SPECIFIC DETAILS.
&&
.HYDROLOGY...
RAINFALL AMTS SHOULD GENERALLY BE ONE QUARTER...TO ONE HALF OF AN
INCH FOR AREAS NEAR AND TO THE SOUTH/WEST OF THE GREATER CAPITAL
REGION THROUGH THURSDAY...WITH LESS THAN ONE QUARTER OF AN INCH
TO THE NORTH AND EAST. SOME MINOR...WITHIN BANK RISES ARE POSSIBLE
FOR AREAS WHERE RAINFALL AMTS REACH ONE HALF INCH OR
GREATER...SUCH AS ON THE ESOPUS...RONDOUT AND SCHOHARIE CREEKS.
GENERALLY DRY CONDITIONS ARE EXPECTED FOR LATE THURSDAY THROUGH
AT LEAST EARLY SATURDAY.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...KL
HYDROLOGY...KL
AREA FORECAST DISCUSSION
NWS LINCOLN IL
310 AM CDT TUE OCT 23 2012
.DISCUSSION...
ISSUED 310 AM CDT TUE OCT 23 2012
WARM FRONT CURRENTLY LOCATED OVER NORTHERN ILLINOIS...ROUGHLY
ALONG THE I-80 CORRIDOR. HAVE BEEN SEEING SHOWERS AND STORMS
INCREASING ACROSS WESTERN ILLINOIS AND ESPECIALLY OVER
MISSOURI...AS AN UPPER WAVE MOVES INTO THE AREA AND AN APPARENT
MESOSCALE VORTEX TRACKS ACROSS MISSOURI PER WATER VAPOR IMAGERY.
INITIAL FORECAST CONCERN INVOLVES CONVECTIVE TRENDS FOR PRIMARILY
THIS MORNING...ALONG WITH ITS EFFECTS ON TEMPERATURES. IN THE
LONGER RANGE...THE TIMING OF A STRONG COLD FRONT ON THURSDAY
REMAINS AN ISSUE...ALONG WITH RAIN TRENDS THURSDAY AND FRIDAY.
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
LATEST HRRR DOING A REASONABLE JOB WITH THE CONVECTION OVER
MISSOURI...AND IT CONTINUES TO INCREASE THE RAIN OVER MOST OF THE
CWA THROUGH EARLY MORNING. AS SUCH...HAVE RAMPED UP RAIN CHANCES
TO THE LIKELY RANGE IN MOST AREAS...PRIMARILY ALONG AND EAST OF
I-55. ANY LINGERING RAIN SHOULD BE TAPERING OFF EARLY IN THE
AFTERNOON. THE CONVECTION YESTERDAY REALLY THREW OFF THE HIGH
TEMPERATURE FORECAST...AND WILL HAVE TO KEEP THAT POTENTIAL IN
MIND FOR TODAY...ESPECIALLY IF CLOUDS ARE SLOW TO MOVE OUT. HAVE
LOWERED HIGHS FOR TODAY BY A FEW DEGREES IN MOST AREAS...CLOSER TO
A MET/MAV BLEND. HOWEVER...HAVE KEPT HIGHS NEAR 80 DEGREES ON
WEDNESDAY AND OVER THE EASTERN 2/3 OF THE CWA ON THURSDAY AS WELL.
UPPER WAVE CURRENTLY OVER THE PACIFIC NORTHWEST IS EXPECTED TO
FORM A CLOSED LOW AS IT MOVES NORTHEAST TO THE CANADIAN PRAIRIES
BY EARLY WEDNESDAY. 50-70 KNOT JET AT 500 MB WILL FOLLOW A WAVE
SLIDING ALONG THE SOUTHERN JET STREAM TO FEED INTO THE AREA AHEAD
OF THE COLD FRONT. LATEST MODEL GUIDANCE BRINGS THE FRONT INTO THE
NORTHWESTERN CWA THURSDAY AFTERNOON...AND ENTERING THE SOUTHEAST
CWA TOWARD MIDNIGHT. A NARROW WINDOW OF OPPORTUNITY EXISTS FOR
SOME STRONGER STORMS AHEAD OF THE FRONT THURSDAY AFTERNOON...
ALTHOUGH RAPIDLY INCREASING CLOUDS MAY THWART THIS POTENTIAL.
HOWEVER...THE RAIN WILL BE ON THE INCREASE...AND HAVE INTRODUCED
LIKELY POPS NORTHWEST OF THE ILLINOIS RIVER DURING THE AFTERNOON.
WITH THE BULK OF THE RAIN BEHIND THE FRONT...WILL SPREAD THE
LIKELY POPS FROM WEST TO EAST...WITH THE RAIN DIMINISHING WEST OF
I-55 AFTER MIDNIGHT.
LONG TERM...FRIDAY THROUGH MONDAY...
MODELS HAVE BEEN BACKING OFF ON THE IDEA OF A SECONDARY WAVE
FEEDING THE AREA BEHIND THE FRONT...WITH THE 00Z ECMWF THE ONLY
ONE STILL WITH THIS GENERAL TREND. WILL DROP THE RAIN CHANCES
NORTHWEST OF THE ILLINOIS RIVER ON FRIDAY AND FRIDAY NIGHT...AND
LOWER THEM QUITE A BIT FURTHER EAST. HOWEVER...THE GFS AND
CANADIAN MODELS WOULD SUGGEST COMPLETELY DRY CONDITIONS BY EARLY
FRIDAY EVENING EVERYWHERE...SO WILL NEED TO SEE IF THIS TREND
CONTINUES. HAVE REMOVED THE RAIN ON SATURDAY ASIDE FROM SOME
SLIGHT CHANCES EAST OF I-57...MAINLY DURING THE MORNING.
WEEKEND TREND STILL LOOKS QUITE CHILLY...WITH HIGHS IN MANY AREAS
STRUGGLING TO REACH THE 50 DEGREE MARK. SUB-FREEZING LOWS ARE
EXPECTED ALONG AND WEST OF I-55 BY SUNDAY MORNING. BEYOND
THAT...THE FORECAST TRENDS BECOME COMPLICATED BY A TROPICAL SYSTEM
MOVING NORTHWARD OFF THE EAST COAST. ECMWF MODEL IS MORE AFFECTED
AND FORMS A CUTOFF LOW OVER THE GREAT LAKES...LINGERING THE CHILLY
WEATHER INTO EARLY NEXT WEEK...WHEREAS THE GFS IS MORE PROGRESSIVE
AND MILDER. NEITHER SOLUTION CURRENTLY YIELDS ANY PRECIPITATION
FOR OUR AREA SUNDAY AND MONDAY.
GEELHART
&&
.AVIATION...
ISSUED 1141 PM CDT MON OCT 22 2012
SHORT-WAVE TROUGH EVIDENT ON 04Z WATER VAPOR IMAGERY OVER EASTERN
KANSAS WILL LIFT NORTHEASTWARD...BRINGING ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS TO CENTRAL ILLINOIS LATE TONIGHT INTO TUESDAY
MORNING. 0430Z RADAR MOSAIC SHOWS SCATTERED SHOWERS ACROSS CENTRAL
MISSOURI...WITH A CLUSTER OF CONVECTION DEVELOPING ACROSS SOUTHWEST
MISSOURI. AS UPPER WAVE APPROACHES AND LOW-LEVEL JET INCREASES...THINK
SHOWERS/STORMS WILL BECOME MORE WIDESPREAD ACROSS MISSOURI OVER
THE NEXT COUPLE OF HOURS. THIS PRECIPITATION WILL THEN SPREAD
NORTHEASTWARD INTO CENTRAL ILLINOIS TOWARD DAWN. BASED ON THE 01Z
HRRR AND LATEST RADAR TRENDS...HAVE INTRODUCED PREDOMINANT SHOWERS
AT KSPI BY 08Z...THEN FURTHER NORTHEAST TO KBMI AND KCMI BY 10Z.
WILL CARRY SHOWERS FOR ABOUT 7 TO 8 HOURS AT EACH TERMINAL...ENDING
FROM WEST TO EAST TOWARD MIDDAY. TIMING OF INDIVIDUAL THUNDERSTORMS
AT EACH TAF SITE REMAINS DIFFICULT...SO WILL ONLY MENTION VCTS AT
THIS TIME. ONCE UPPER WAVE TRACKS OFF TO THE NORTHEAST...SHOWERS
WILL COME TO AN END AND SKIES WILL GRADUALLY CLEAR BY TUESDAY
AFTERNOON/EVENING. WINDS WILL INITIALLY BE FROM THE SOUTH AT
AROUND 10KT TONIGHT...THEN WILL INCREASE AND GUST TO AROUND 20KT
ONCE THE RAIN ENDS TUESDAY AFTERNOON.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1238 AM EDT TUE OCT 23 2012
.AVIATION...
A STATIONARY FRONT WAS JUST NORTH OF THE INDIANA LINE WITH SHOWERS
AND THUNDERSTORMS MOVING EAST ALONG AND NEAR THE FRONT. ADDED SOME
TEMPO IFR CIGS AT SBN 10-14Z GIVEN SOME UPSTREAM IFR CONDITIONS AND
THE ONGOING SHOWERS. THE LATEST GFS/LAMP GUIDANCE ALSO SUPPORTS
IFR CONDITIONS. OTHERWISE...CONDITIONS SHOULD GRADUALLY IMPROVE
LATER IN THE DAY AS WINDS CONTINUE FROM THE SOUTH. FWA SHOULD BE
MAINLY VFR...ALTHOUGH A TEMPO IFR AREA IS POSSIBLE EARLY THIS
MORNING.
&&
.PREV DISCUSSION... /ISSUED 320 PM EDT MON OCT 22 2012/
SHORT TERM... /TONIGHT THROUGH TUESDAY NIGHT/
COMPLEX SHORT TERM FORECAST GIVEN PROBLEMATIC MCV ROTATING THROUGH
WESTERN LAKES THIS AFTERNOON. CONVECTION HAS FIRED AHEAD OF MAIN
SHORT WAVE IN AREA OF STRONG THETA E ADVECTION WITH LOW LEVEL JET.
SATELLITE AND RADAR MOSAIC SHOWS MCV DEVELOPED OVER NORTHERN IL AND
LIFTING NORTH INTO WI. 12Z 4KM WRF WAS A TOTAL BUST WITH NO
INDICATION OF THIS LINE OF CONVECTION AT 18Z. HRRR WAS PERFORMING
WELL ON A FEW OF ITS RUNS AND GENERALLY FOLLOWED WITH SOME
EXTRAPOLATION. MOST SPECTRAL GUIDANCE DID NOT MODEL MCV AND
ASSOCIATED SUBSIDENCE IN ITS WAKE WHICH HAS LIMITED ANY FURTHER
DEVELOPMENT. SPECTRAL MODELS SEEM OVER AGGRESSIVE WITH ADDITIONAL
PCPN DEVELOPMENT THIS EVENING INTO EARLY OVERNIGHT HOURS IN AREA
NEAR WARM FRONT BUT BETWEEN SYNOPTIC SHORT WAVES. HAVE TIMED CURRENT
CONVECTION ACROSS CWA INTO EARLY EVENING HOURS WITH A DIMINISHING
TREND. KEPT CHANCE POPS GOING ENTIRE AREA THIS EVENING. SECOND SHORT
WAVE AND PV ANOMALY APPROACH LATE TONIGHT AND THIS FEATURE SLOWER
THAN PREVIOUS RUNS. NOW LOOKS LIKE THIS WILL IMPACT MOST OF AREA ON
TUESDAY. HAVE ADJUSTED TIMING/DETAIL OF POPS WITH LIKELY LATE
TONIGHT AND TUE MORNING ALL BUT SE AREAS. KEPT A CHANCE ACROSS
NORTHEAST TUE AFTERNOON WITH SHORT WAVE OVER THE AREA BUT MOVING
EAST. TEMPS WILL REMAIN WARM THROUGH THE PERIOD WITH LOWS IN UPPER
50S TO LOWER 60S. HIGHS ON TUE AGAIN TRICKY WITH CLOUDS AND PCPN BUT
SINCE WE MANAGED TO REACH 70 MOST AREAS TODAY SEE SIMILAR NUMBERS ON
TUE WITH MID 70S POSSIBLE SOUTH WHERE RAIN ENDS IN MORNING. BLENDED
GUIDANCE LOOKS GOOD.
LONG TERM... /WEDNESDAY THROUGH MONDAY/
UNSEASONABLY WARM WEATHER WILL BE IN STORE INTO THURSDAY WITH
CONTINUED SOUTHWESTERLY FLOW INTO THE REGION. MODELS IN GOOD
AGREEMENT THROUGH THURSDAY WITH 850 MB TEMPS IN THE +15 TO +17
CELSIUS RANGE. SOUNDINGS WOULD SUGGEST THAT TEMPS WILL ONLY MIX
THROUGH AROUND 900 MB YIELDING HIGHS IN THE MID TO UPPER 70S WEDS
AND THURS AFTERNOON WHICH IS INLINE WITH PREV GRIDS AND NEAR OR
ABOVE GUIDANCE. IF FULL MIX OUT THROUGH 850 MB OCCURS...TEMPS COULD
JUMP INTO THE LOWER 80S.
FORECAST BECOMES MORE MUDDLED THROUGH THE REMAINDER OF THE FORECAST
IN TERMS OF HANDLING OF SEVERAL LARGE SCALE FEATURES. FIRST IS LARGE
TROUGH WHICH WILL BE DIGGING INTO THE PLAINS WITH MAIN UPPER LEVEL
SYSTEM IN CENTRAL CANADA. THIS FEATURE DRIVES A STRONG COLD FRONT
THROUGH THE AREA IN THURS NGT/FRI TIME FRAME. FROM HERE THE MODELS
BEGIN TO DIVERGE ON HANDLING OF PROGRESSIVENESS OF THE TROUGH. 12Z
GFS HAS KEPT A POSITIVELY TILTED SYSTEM SWEEPING THROUGH AND COLDER
AIR ARRIVING BEHIND IT WITH LITTLE LINGERING PRECIP. 00Z ECMWF
STALLED THE FRONT ACROSS THE REGION WITH ADDITIONAL ENERGY MOVING
ALONG IT TO BRING CHANCES INTO SATURDAY. 12Z GEFS/GEM/00Z ECMWF THEN
INDICATE TROUGH BECOMES SOMEWHAT NEGATIVELY TILTED. THIS BRINGS TO
LIGHT THE 2ND FEATURE OF CONCERN...WHAT WILL LIKELY BECOME TROPICAL
SYSTEM SANDY LATER TODAY. MODELS GENERALLY INTENSIFY THE SYSTEM AND
TRACK INTO THE WESTERN ATLANTIC. THIS WILL CAUSE A BLOCKY PATTER TO
ESTABLISH WITH MODELS BOUNCING BACK AND FORTH ON POSSIBLE PHASING OF
SOME OF THE TROPICAL ENERGY AND THE TROUGH...DEVELOPING A LARGE
STORM SYSTEM THAT COULD BRING IN A BLAST OF COLD AIR AND CHANCES FOR
RAIN OR SNOW INTO NEXT WEEK. 12Z ECMWF HAS BACKED OFF ON MORE
WESTWARD SOLUTION OF THIS PHASING AND SOMEWHAT MORE REALISTIC
BOMBING OUT OF THE SYSTEM OFF THE EAST COAST. COLDER AIR WILL STILL
ARRIVE REGARDLESS WITH POTENTIAL FOR LAKE EFFECT POSSIBLY IN PLAY.
HAVE TRIED TO KEEP FOR THE MOST PART WITH PREV GRIDS AND UNDERCUT
GUIDANCE WITH TRENDS OF ALL MODELS STILL SUGGESTING A DROP TO WELL
BELOW NORMAL TEMPS. REMOVED SOME OF THE MIXED PRECIP WORDING WITH
1000-850 MB THICKNESS VALUES GENERALLY IN THE 1300 TO 1310 DM
RANGE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...SKIPPER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
507 AM EDT TUE OCT 23 2012
.SYNOPSIS...
A WARM FRONT STALLING ACROSS LAKE ERIE AND NEW YORK STATE WILL CAUSE
SCATTERED SHOWERS TO MOVE EASTWARD ACROSS UPPER OHIO VALLEY INTO
WEDNESDAY MORNING...MAINLY NORTH OF PITTSBURGH. HIGH PRESSURE WILL
FOLLOW WITH DRY WARM WEATHER THURSDAY AND FRIDAY...BEFORE A STRONG
COLD FRONT BRINGS SHOWERS THIS WEEKEND AND A COOL DOWN FOR MUCH OF
NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
BASED ON BLEND OF RECENT RADAR DATA AND RAP MODEL OUTPUT...HAVE
ADJUSTED TIMING AND COVERAGE OF EASTBOUND ISOLATED SHOWERS ACROSS
THE UPPER OHIO VALLEY INTO MIDDAY. LIGHTNING DATA SHOWS NIL CLOUD
TO GROUND STRIKES...SO WILL CONTINUE NOT TO MENTION ANY THUNDER.
USING BLEND OF NAM AND GFS MODEL OUTPUT TO ADJUST SHOWER COVERAGE
THIS AFTERNOON AND TONIGHT...CONTINUED TO FORECAST A SLIGHTLY
HIGHER COVERAGE OF SHOWERS NORTH OF PITTSBURGH...WITH LITTLE IF
ANY SOUTH.
RECENT SREF MODEL OUTPUT SHOWS BROAD HIGH PRESSURE ACROSS
VIRGINIA AND THE CAROLINAS...EXPANDING NORTHWARD TOWARD THE UPPER
OHIO VALLEY TONIGHT AND WEDNESDAY. SO EXPECT LAST OF THE WARM FRONTAL
ISOLATED SHOWERS TO EXIT NORTHEAST PAST THE APPALACHIAN MOUNTAINS
BY MIDDAY WEDNESDAY. HIGH PRESSURE SUBSIDENCE WILL PROMOTE DRY
WARM CONDITIONS THE REST OF WEDNESDAY.
CONTINUED FORECAST OF TEMPERATURES TO BE AS MUCH AS 15 DEGREES
WARMER THAN NORMAL...AS SUPPORTED BY RECENT GFS AND NAM MOS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
RECENT SREF MODEL OUTPUT SHOWS HIGH PRESSURE SUBSIDENCE
MAINTAINING DRY WARM CONDITIONS ACROSS THE UPPER OHIO VALLEY
THURSDAY AND FRIDAY.
CONTINUED FORECAST OF MUCH WARMER THAN NORMAL TEMPERATURES THIS
PERIOD WITH HIGHS THURSDAY NEARLY 20 DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
BLEND OF RECENT GFS/ECMWF/NAEFS MODEL OUTPUT SHOW THE EASTWARD PASSAGE
OF A STRONG COLD FRONT THROUGH THE UPPER OHIO VALLEY
SATURDAY...WITH A CHANCE OF THE FIRST PREFRONTAL SHOWERS ARRIVING
LATE FRIDAY NIGHT. HAVE CONTINUED MENTION OF A CHANCE OF SHOWERS
SATURDAY INTO MONDAY...DUE TO FRONTAL DYNAMICS...POST SYSTEM COLD
INSTABILITY...AND POSSIBLE INTERACTION WITH A DEEPENING COASTAL
LOW PRESSURE SYSTEM.
FORECASTED TEMPERATURES TO COOL SHARPLY WITH THE COLD FRONTAL
PASSAGE SATURDAY...WITH TEMPERATURES GENERALLY 5 TO 10 DEGREES
COLDER THAN NORMAL SUNDAY AND MONDAY.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
SLIGHTLY BELOW NORMAL CONFIDENCE WITH 06Z TAFS. AT FKL/DUJ...MAIN
QUESTION IS WHETHER CONDITIONS MAY DROP TO MVFR DURING TIME PERIOD.
ELSEWHERE...CONDITIONS ARE EXPECTED TO REMAIN VFR...ALTHOUGH CLOUD
HEIGHTS ARE A BIT IN QUESTION. MODEL SOUNDINGS REALLY DON/T SEEM TO
HAVE MUCH AGREEMENT ON AMOUNT OF MOISTURE PRESENT. WILL STICK PRETTY
CLOSE TO INHERITED BKN CIGS AT MID LEVELS. SCATTERED SHOWERS SHOULD
NOT DROP MUCH FARTHER SOUTH THAN INTERSTATE 80. THINK THAT BULK OF
RAINFALL WILL REMAIN NORTH OF FKL/DUJ...SO WILL KEEP EXPLICIT RAIN
MENTION OUT OF TAFS AT THIS TIME.
.OUTLOOK.../WEDNESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL CONTINUE TO PREVAIL THROUGH DAYTIME FRIDAY.
RESTRICTIONS CAN OCCUR FRIDAY NIGHT AND SATURDAY DUE TO SHOWERS
ASSOCIATED WITH A STRONG COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
200 AM EDT TUE OCT 23 2012
.SYNOPSIS...
A WARM FRONT STALLING ACROSS LAKE ERIE AND NEW YORK STATE MAY
CAUSE SCATTERED SHOWERS TO MOVE EASTWARD ACROSS UPPER OHIO
VALLEY INTO WEDNESDAY MORNING...MAINLY NORTH OF PITTSBURGH. HIGH
PRESSURE WILL FOLLOW WITH DRY WARM WEATHER THURSDAY AND
FRIDAY...BEFORE A STRONG COLD FRONT BRINGS SHOWERS THIS WEEKEND AND
A COOL DOWN FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
BASED ON BLEND OF RECENT RADAR DATA AND RAP MODEL OUTPUT...HAVE
ADJUSTED TIMING AND COVERAGE OF EASTBOUND ISOLATED SHOWERS ACROSS
THE UPPER OHIO VALLEY THROUGH THIS MORNING. LIGHTNING DATA SHOWS
ISOLATED THUNDERSTORMS OVER NORTHERN OHIO...HOWEVER EXPECT THESE
TO DIE BEFORE REACHING PLACES LIKE NEW PHILADELPHIA OHIO OR
FRANKLIN PENNSYLVANIA.
THEN USED BLEND OF NAM AND GFS MODEL OUTPUT TO ADJUST SHOWER
COVERAGE THIS AFTERNOON AND TONIGHT. COMPOSITE OF THIS MODEL
OUTPUT SHOW A HIGHER CHANCE OF SHOWERS NORTH OF PITTSBURGH THAN
SOUTH.
CONTINUED FORECAST OF TEMPERATURES TO BE AS MUCH AS 15 DEGREES
WARMER THAN NORMAL...AS SUPPORTED BY RECENT GFS AND NAM MOS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS BROAD HIGH PRESSURE ACROSS
VIRGINIA AND THE CAROLINAS...EXPANDING NORTHWARD TOWARD THE UPPER
OHIO VALLEY THIS PERIOD. SO EXPECT LAST OF THE WARM FRONTAL
ISOLATED SHOWERS TO EXIT NORTHEAST PAST THE APPALACHIAN MOUNTAINS
BY MIDDAY WEDNESDAY. HIGH PRESSURE SUBSIDENCE WILL PROMOTE DRY
WARM CONDITIONS THE REST OF WEDNESDAY AND THURSDAY.
CONTINUED FORECAST OF WARMER THAN NORMAL TEMPERATURES THIS PERIOD
WITH HIGHS THURSDAY NEARLY 20 DEGREES ABOVE NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THERE IS GFSE/ECMWF/NAEFS AGREEMENT THAT THE UPPER OHIO VALLEY
WILL CONTINUE TO BE IN A DRY AND WARM SOUTHWESTERLY FLOW THURSDAY
NIGHT THROUGH FRIDAY NIGHT. TEMPERATURES THROUGH THIS PERIOD WILL
BE AROUND 15 DEGREES ABOVE NORMAL.
A COLD FRONT IS PROGGED TO APPROACH FROM THE WEST ON FRIDAY NIGHT
AND CROSS THE FORECAST AREA ON SATURDAY. THERE IS STILL SOME
UNCERTAINTY IN REGARDS TO THE TIMING OF ITS PASSAGE AND DUE TO
THIS THE FORECAST DOES NOT WAVER TOO FAR FROM THE HPC SOLUTION.
AFTER THE COLD FRONT PASSES...THERE IS A QUITE A BIT OF
UNCERTAINTY FOR THE LATE WEEKEND INTO MONDAY. THE 00Z ECMWF/12Z
CANADIAN AMPLIFY A NORTHERN STREAM MID-LEVEL TROUGH AND BEGIN TO
TAP INTO TROPICAL MOISTURE FROM WHAT IS NOW TD 18. MEANWHILE...THE
12Z GFS INDICATES A MUCH FLATTER PATTERN...TAKING THE TROPICAL
SYSTEM FURTHER EASTWARD INTO THE ATLANTIC AND LEAVING THE UPPER
OHIO VALLEY IN A SOUTHWESTERLY FLOW. GIVEN THE HIGH DEGREE OF
UNCERTAINTY...THE FORECAST REMAINS FAIRLY CLOSE TO HPC AND ALSO
CONSIDERS THE NAEFS MEAN WITH LOW CHANCE POPS AND TEMPS 5 TO 10
DEGREES BELOW SEASONAL NORMALS.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
SLIGHTLY BELOW NORMAL CONFIDENCE WITH 06Z TAFS. AT FKL/DUJ...MAIN
QUESTION IS WHETHER CONDITIONS MAY DROP TO MVFR DURING TIME PERIOD.
ELSEWHERE...CONDITIONS ARE EXPECTED TO REMAIN VFR...ALTHOUGH CLOUD
HEIGHTS ARE A BIT IN QUESTION. MODEL SOUNDINGS REALLY DON/T SEEM TO
HAVE MUCH AGREEMENT ON AMOUNT OF MOISTURE PRESENT. WILL STICK PRETTY
CLOSE TO INHERITED BKN CIGS AT MID LEVELS. SCATTERED SHOWERS SHOULD
NOT DROP MUCH FARTHER SOUTH THAN INTERSTATE 80. THINK THAT BULK OF
RAINFALL WILL REMAIN NORTH OF FKL/DUJ...SO WILL KEEP EXPLICIT RAIN
MENTION OUT OF TAFS AT THIS TIME.
.OUTLOOK.../WEDNESDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL CONTINUE TO PREVAIL UNTIL FRIDAY NIGHT AND
SATURDAY WHEN A COLD FRONT APPROACHES FROM THE WEST AND BRINGS
SHOWERS WITH RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
315 AM CDT TUE OCT 23 2012
.DISCUSSION...
SHRTWV ACROSS EASTERN SD/NE NEBRASKA ALONG WITH AMPLE MOISTURE
SURGING NORTHWARD FROM EARLIER CONVECTION ACROSS SOUTHERN IA...HAS
LED TO MORE NUMEROUS SHRA/TSRA DEVELOPMENT ACROSS S MN. IT LOOKS
AS THOUGH THESE STORMS WERE ABLE TO TAP SOME ELEVATED INSTABILITY
ACROSS S MN DURING THE OVERNIGHT HRS. HOWEVER...THIS SHOULD BE
SHORT LIVED AS DEEPER MOISTURE WILL LIFT NORTHWARD ALLOWING FOR
MAINLY -DZ/FG TO PERSIST ACROSS S MN BEFORE DRIER AIR BEGINS TO
EVADE FROM THE CENTRAL PLAINS. THE DRIER AIR IS ALSO ANOTHER
PROBLEM AS THE FG/STRATUS HAS DEVELOPED AS FAR SOUTH AS KANSAS
WHICH MAY CONTINUE THE LOWER CLDS/FG IN S MN THEN PREVIOUS
FORECAST THAT HAD SOME SUNSHINE THIS AFTN. BIGGEST FACTOR FOR
CONTINUING FG/LOW CLDS THRU MIDDAY IS WHETHER THE DEPTH OF THE
STRATUS ACROSS NE/KS IS SHALLOW ENOUGH TO MIX OUT. WITH A MORE
PESSIMISTIC FORECAST ON CLD CVR...HAD LOWERED AFTN TEMPS A FEW
DEGREES. MAINLY FOLLOWING A SURGE OF HIGHER DEW PTS WHICH WILL
LEAD TO TEMPS IN THE 60S...WITH A FEW 70S ALONG THE IA BORDER.
AFT THE MORNING CONVECTION...MOST OF THE SHORT TERM FORECAST WILL
DEAL WITH THE STRONG SHRTWV/LONG WAVE TROUGH ACROSS THE WESTERN
U.S. AND HOW IT WILL TRANSLATE ACROSS THE PLAINS...AND INTO THE
UPPER MIDWEST BY MIDWEEK. MODELS ARE DEPICTING SEVERAL WEAK
SHRTWV/S RIDING NE ALONG A NEARLY STATIONARY FRONTAL BOUNDARY
LATER TONIGHT ACROSS EASTERN MN. ALONG AND AHEAD OF THIS
FRONT...VERY MILD AIR WILL LEAD TO ADDITIONAL CONVECTION...BUT
UNCERTAINTIES EXIST ON HOW WIDESPREAD THE ACTIVITY BECOMES IN THE
NEXT 24 HRS. WILL LEAN TOWARD ONLY CHC POPS THROUGH LATE
TONIGHT...BEFORE THE MAIN SHRTWV AND UPPER LEVEL SUPPORT SHOULD
INDUCE A LONG AREA OF PRECIPITATION ACROSS THE UPPER MIDWEST.
PRECIPITABLE WATER VALUES ARE OVER ONE INCH ALONG AND SOUTH OF
THIS FRONT...SO RAINFALL AMTS COULD BE LOCALLY HEAVY IN SC/EC MN
AS WELL AS WC WI ON WED/EARLY THU. ONCE THE MUCH COOLER AIR BEGINS
TO FILTER ACROSS THE UPPER MIDWEST...EXPECT RAINFALL AMTS TO
LESSEN...WITH THE CHC OF -SN IN WC MN EARLY THU MORNING BEFORE THE
PRECIPITATION ABRUPTLY ENDS BY MIDDAY. COOL -RA WILL OCCUR IN THE
EASTERN FA WHICH DEEPER MOISTURE WILL HOLD ON UNTIL THE LATE AFTN.
THE EXTENDED PERIOD REMAINS THE SAME WITH THE LARGE LONG WAVE
TROUGH DEVELOPING ACROSS THE U.S...MAINLY EAST OF THE ROCKIES.
THERE REMAINS SOME SUBTLE WAVES LATE IN THE WEEKEND...EARLY NEXT
WEEK ALONG THE TRANSITION ZONE OF MORE PACIFIC AIR MOVING ACROSS
THE ROCKIES. THIS MAY GENERATE A FEW RAIN OR SNOW SHOWERS
SUNDAY...AND POSSIBLE MONDAY. HOWEVER...BY MONDAY THE ATMOSPHERE
SHOULD BE WARM ENOUGH TO BE ALL IN THE FORM OF RAIN. ..JLT..
&&
.AVIATION.../06Z TAF ISSUANCE/
THINKING HAS NOT CHANGED MUCH FROM 00Z SET OF TAFS AND
ACCOMPANYING DISCUSSION. ONLY REAL CHANGE WAS FOR A SOMEWHAT
SLOWER INVASION OF LOWER CEILINGS AND VISIBILITIES... WHICH WAS
MENTIONED AS A POSSIBILITY. THINGS SEEM TO BE IN LINE WITH SREF
GUIDANCE AND LATEST NARRE-TL AS WELL. DIDN/T CHANGE PREVIOUS
FORECAST MUCH OTHER THAN TO PUSH BACK TIMING SOME... AND OTHERWISE
KEPT THINGS FAIRLY PESSIMISTIC THROUGH THE DAY AS VERY MOIST
PROFILE MOVES ACROSS THE AREA OVERNIGHT THROUGH MOST OF THE DAY ON
TUESDAY. IMPROVEMENT SHOULD OCCUR ON THE BACKSIDE OF UPPER WAVE
AND SURFACE IMPULSE LATE TOMORROW AFTERNOON AND TOMORROW
EVENING... SO DID ALLOW FOR RETURN OF VFR CONDITIONS DURING THAT
TIME FRAME.
KMSP...THERE IS DEFINITELY SOME UNCERTAINTY STILL ON THE TIMING OF
ARRIVAL AND DEPARTURE OF IFR AND LIFR CONDITIONS... AS WELL AS
EXACTLY HOW LOW CEILINGS AND VISIBILITIES WILL GET LATE TONIGHT
AND TUESDAY MORNING. STAYED CLOSE TO PREVIOUS FORECAST... WHICH IS
IN LINE WITH SOME OF THE UPSTREAM OBSERVATIONS AS WELL AS THE
TIME-HEIGHT FORECASTS FROM THE RAP AND NAM. HOWEVER... TIMING
COULD STILL VARY SEVERAL HOURS FROM INDICATED... PARTICULARLY WITH
THE IMPROVEMENT OF CONDITIONS ON TUESDAY.
/OUTLOOK FOR KMSP/
WEDNESDAY...IFR CEILINGS AND VISIBILITIES POSSIBLE... MVFR LIKELY.
WINDS NORTHEAST 5-10 KTS.
THURSDAY...IFR CEILINGS AND VISIBILITIES EXPECTED IN THE MORNING. WINDS
NORTHWEST 10-15 KTS.
FRIDAY...VFR CONDITIONS EXPECTED. WINDS NORTHWEST AROUND 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/TRH
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
349 AM CDT TUE OCT 23 2012
.SHORT TERM...
ISSUED AT 214 AM CDT TUE OCT 23 2012
(TODAY AND TONIGHT)
FOCUS WILL ONCE AGAIN BE TSRA CHANCES TODAY...TURNING TO TEMPS ONCE
PRECIP HAS ENDED.
ONGOING TSRA JUST W OF THE CWA IS ANTICIPATED TO CONTINUE TO MOVE
ENE THRU THE CWA TODAY. THE 23/04Z HRRR AND 23/00Z 4KM NCEP WRF ARE
IN GOOD AGREEMENT AND HANDLE THE ONGOING SITUATION RATHER WELL. PLAN
IS TO CLOSELY FOLLOW THESE MDLS FOR POPS TODAY...PROVIDED THIS TREND
CONTINUES. THESE MDLS...AS WELL AS THE OPERATIONAL MDLS...ARE IN
GOOD AGREEMENT WITH PRECIP ENDING BY EARLY AFTERNOON AT THE LATEST
AS THE S/W WILL BE NEARING THE IL/IN BOARDER BY 21Z.
WITH PRECIP COMING TO AN END AND CLOUDS CLEARING THRU THE
AFTERNOON...AMPLE INSOLATION SHUD BE AVAILABLE FOR A QUICK WARM UP
TODAY. MADE ONLY MINOR CHANGES TO THE GOING FORECAST FOR TEMPS TODAY
AND TONIGHT. RAISED TEMPS A COUPLE OF DEGREES ACROSS CNTL MO AS
850MB TEMPS SHUD BE NEARING 18C ACCORDING TO THE NAM. WHILE THIS IS
A WARM OUTLIER AMONG THE 00Z GUIDANCE...THIS SOLN SEEMS PROBABLE
GIVEN THE WARM 850MB TEMPS ADVECTING NEWD BEHIND THIS S/W. THAT
SAID...MDL SOUNDINGS FOR TODAY SUGGEST MUCH OF THE REGION WILL NOT
MIX TO 850MB AND HAVE THEREFORE TRENDED TWD THE WARMER
GUIDANCE...BUT REMAINED JUST UNDER ACROSS CNTL MO. SIMILAR TRENDS
CONTINUE TONIGHT WITH SLY TO SWLY WINDS WILL REMAIN AOA 7 KTS.
TILLY
&&
.LONG TERM...
ISSUED AT 349 AM CDT TUE OCT 23 2012
(WEDNESDAY THROUGH THURSDAY)
ONCE THE S/W RESPONSIBLE FOR THE ONGOING TSRA MOVES E OF THE
AREA...THE SHORT TERM IS EXPECTED TO REMAIN DRY UNTIL THURS. MDLS
ARE IN RELATIVELY GOOD AGREEMENT UNTIL WED NIGHT. THE GFS SUGGESTS A
REINFORCING S/W ROUNDING THE BASE OF THE UPPER LOW WHICH HELPS TO
SPEED UP FROPA THURS NIGHT. HAVE TRENDED TWD THE CONSENSUS OF THE
OTHER MDLS...BUT KEPT CHANCE POPS TO ACCOUNT FOR THE FASTER GFS
SOLN.
UNTIL THURS...FOCUS REMAINS TEMPS. NOT MUCH HAS CHANGED WITH THE
23/00Z GUIDANCE AND SAW NO REASON TO MAKE MANY CHANGES TO THE GOING
FORECAST. OVERALL...CONTINUED TREND GOING AOA WARMEST GUIDANCE.
(FRIDAY THROUGH MONDAY)
MDL TRENDS DO NOT CHANGE MUCH EARLY IN THE EXTD PERIOD. THE 22/18Z
DGEX DEVELOPS AN AMPLIFIED TROF WITH THE SYSTEM AFFECTING THE CWA AT
THE BEGINNING OF THE PERIOD AND CONTINUES TO DEEPEN THIS TROF THRU
THE WEEKEND. THIS SOLN IS AN OUTLIER AMONG THE OPERATIONAL
MDLS...EVEN AMONG THE GEFS...AND HAVE TRENDED TWD THE OTHER
OPERATIONAL MDLS THRU THE PERIOD.
THE GEM BEGINS TO SPEED UP TO COME INTO BETTER AGREEMENT WITH THE
GFS LATE FRI INTO SAT. HAVE THEREFORE TRENDED TWD THESE SOLNS
REGARDING POPS LOWERING POPS FRI NIGHT ACROSS NWRN PORTIONS OF THE
CWA AND KEPT SAT DRY. REMAINDER OF THE EXTD IS DRY FOR NOW...BUT
MDLS SUGGEST A COUPLE OF S/WS THAT MAY BRING PRECIP ACROSS NRN
PORTIONS OF THE CWA LATE IN THE EXTD PERIOD.
AS FOR TEMPS...MDLS ARE IN RELATIVELY GOOD AGREEMENT EARLY IN THE
PERIOD...LARGE DIFFERENCES BEGIN BY SUN AND PROVIDE A VARIETY OF
SOLNS THRU THE PERIOD. HAVE TRENDED TWD A COMPROMISE OF THE
GFS/ECMWF/GEM FOR FRI. WITH UNCERTAINTY GROWING THRU THE EXTD...HAVE
TRENDED TWD A BLEND OF THE GFS/ECMWF BEYOND FRI AS THESE SOLNS
REMAIN SOMEWHAT CLOSE.
TILLY
&&
.AVIATION...
ISSUED AT 1057 PM CDT MON OCT 22 2012
AN INITIAL BATCH OF SCATTERED SHOWERS WAS MOVING NEWD THROUGH COU
LATE THIS EVNG. A BETTER COVERAGE OF SHOWERS AND STORMS IS
EXPECTED LATE TGT AND TUE MRNG AHEAD OF A SHORTWAVE TROUGH NOW
OVER ERN PORTIONS OF KS AND OK WHICH WILL MOVE E-NEWD THROUGH MO
LATE TGT AND TUE MRNG. AN AREA OF SHOWERS AND THUNDERSTORMS MOVING
NEWD THROUGH SWRN MO SHOULD MOVE THROUGH OUR AREA LATE TGT AND
EARLY TUE MRNG. WILL INCLUDE VCTS IN THE TAFS AND A TEMPO GROUP OF
SHOWERS DURING THIS TIME PERIOD. THERE WILL BE PLENTY OF LOW-MID
LEVEL CLOUDS LATE TGT AND TUE MRNG BUT THIS SHOULD BE VFR OUTSIDE
OF SHOWERS/STORMS. SLY SFC WINDS WILL CONTINUE THIS FORECAST
PERIOD AS THE WARM FRONT HAS MOVED N OF THE TAF SITES. THERE MAY
BE SOME LLWS LATE TGT AND EARLY TUE MRNG BUT IT DOES NOT APPEAR
STRONG ENOUGH TO INCLUDE IN THE TAFS WITH THE SWLY LOW LEVEL JET
TRANSLATING NEWD THROUGH OR NEAR COU AND UIN LATE TGT AND EARLY
TUE MRNG. THE CLOUDS SHOULD SCATTER OUT TUE AFTN INTO TUE EVNG
WITH THE WARM FRONT WELL N OF OUR AREA AND THE SHORTWAVE E OF THE
REGION.
SPECIFICS FOR KSTL...THE SHOWERS AND STORMS ACROSS SWRN MO SHOULD
MOVE NEWD UP THE I-44 CORRIDOR AND INTO STL LATE TGT BY 08-09Z TUE.
WILL INCLUDE VCTS ALONG WITH A TEMPO GROUP OF SHOWERS AFTER THIS TIME.
THE SHOWERS AND STORMS SHOULD MOVE NE OF STL BY LATE TUE MRNG.
VFR LOW-MID LEVEL CLOUD CEILING SHOULD PREVAIL LATE TGT AND TUE
MRNG...THEN THE CLOUDS SHOULD SCATTER OUT TUE AFTN OR EARLY TUE
EVNG. SLY SFC WIND WILL CONTINUE LATE TGT AND INCREASE TO AROUND
13-14 KTS TUE AFTN...THEN WEAKEN TUE EVNG.
GKS
&&
.CLIMATE...
ISSUED AT 319 PM CDT SUN OCT 21 2012
RECORD HIGHS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
OCTOBER 23 86(1939) 91(1939) 86(1939)
OCTOBER 24 85(1940) 86(1940) 84(1940)
RECORD HIGH MINIMUMS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
OCTOBER 23 67(2010) 65(1963) 63(1991)
OCTOBER 24 66(1991) 65(1991) 65(1991)
OCTOBER 25 69(1939) 68(1939) 63(1963)
MILLER
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 83 63 86 66 / 80 5 0 10
QUINCY 83 62 83 64 / 60 10 5 10
COLUMBIA 86 64 86 65 / 60 10 0 10
JEFFERSON CITY 86 64 86 65 / 70 10 0 10
SALEM 80 62 83 62 / 80 5 0 5
FARMINGTON 82 59 83 59 / 80 5 0 5
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
215 AM CDT TUE OCT 23 2012
.SHORT TERM...
ISSUED AT 214 AM CDT TUE OCT 23 2012
(TODAY AND TONIGHT)
FOCUS WILL ONCE AGAIN BE TSRA CHANCES TODAY...TURNING TO TEMPS ONCE
PRECIP HAS ENDED.
ONGOING TSRA JUST W OF THE CWA IS ANTICIPATED TO CONTINUE TO MOVE
ENE THRU THE CWA TODAY. THE 23/04Z HRRR AND 23/00Z 4KM NCEP WRF ARE
IN GOOD AGREEMENT AND HANDLE THE ONGOING SITUATION RATHER WELL. PLAN
IS TO CLOSELY FOLLOW THESE MDLS FOR POPS TODAY...PROVIDED THIS TREND
CONTINUES. THESE MDLS...AS WELL AS THE OPERATIONAL MDLS...ARE IN
GOOD AGREEMENT WITH PRECIP ENDING BY EARLY AFTERNOON AT THE LATEST
AS THE S/W WILL BE NEARING THE IL/IN BOARDER BY 21Z.
WITH PRECIP COMING TO AN END AND CLOUDS CLEARING THRU THE
AFTERNOON...AMPLE INSOLATION SHUD BE AVAILABLE FOR A QUICK WARM UP
TODAY. MADE ONLY MINOR CHANGES TO THE GOING FORECAST FOR TEMPS TODAY
AND TONIGHT. RAISED TEMPS A COUPLE OF DEGREES ACROSS CNTL MO AS
850MB TEMPS SHUD BE NEARING 18C ACCORDING TO THE NAM. WHILE THIS IS
A WARM OUTLIER AMONG THE 00Z GUIDANCE...THIS SOLN SEEMS PROBABLE
GIVEN THE WARM 850MB TEMPS ADVECTING NEWD BEHIND THIS S/W. THAT
SAID...MDL SOUNDINGS FOR TODAY SUGGEST MUCH OF THE REGION WILL NOT
MIX TO 850MB AND HAVE THEREFORE TRENDED TWD THE WARMER
GUIDANCE...BUT REMAINED JUST UNDER ACROSS CNTL MO. SIMILAR TRENDS
CONTINUE TONIGHT WITH SLY TO SWLY WINDS WILL REMAIN AOA 7 KTS.
TILLY
&&
.LONG TERM...
ISSUED AT 324 PM CDT MON OCT 22 2012
(TUESDAY THROUGH WEDNESDAY)
CURRENT WV IMAGERY DEPICTS SHORTWAVE TROUGH OVER WESTERN OKLAHOMA. THIS
TROUGH AND ASSOCIATED VORTICITY MAXIMA WILL TRANSLATE ACROSS THE MIDDLE
OF THE CWFA EARLY TOMORROW AND WEAKEN WITH TIME. VERTICAL FORCING FOR ASCENT
WILL INCREASE IMMEDIATELY AHEAD OF THIS FEATURE DUE TO DCPVA. IN ADDITION...
LL FORCING VIA WAA/MOISTURE TRANSPORT VIA A 35-KT LLJ WILL ALSO HELP
SUPPORT LL CONVERGENCE/ASCENT FOR SHOWERS AND THUNDERSTORMS EARLY TOMORROW...
ESPECIALLY FROM MISSISSIPPI RIVER EAST. WENT HIGH CHANCE POPS FOR 12-18 UTC
TOMORROW IN THIS GENERAL AREA BUT DID NOT GO HIGHER DUE TO EXPECTED WEAKER
FORCING AT LOW LEVELS COMPARED TO TODAY AND UNCERTAINTY ON FAVORED REGION
FOR DEVELOPMENT. PRECIPITATION CHANCES SHOULD DIMINISH BY EARLY AFTERNOON...
THOUGH CONFIDENCE IN THIS IS NOT AS HIGH AS IT OTHERWISE WOULD BE AFTER
OBSERVING PRECIPITATION STILL ONGOING AS OF 2000 UTC TODAY WITH CONTINUED
WARM/MOIST ADVECTION.
TEMPERATURES TUESDAY AND WEDNESDAY WILL LIKELY BE VERY WARM...SOME
20 DEGREES ABOVE NORMAL. SOME CONCERN WITH TUESDAYS HIGHS BEING TOO
WARM IF CLOUDS/PRECIP LINGER LONGER THAN EXPECTED LIKE THEY DID TODAY. IN
ADDITION...SOME WEAK CAA/NEUTRAL ADVECTION BEHIND SHORTWAVE TROUGH MAY KEEP
TEMPS A FEW DEGREES COOLER ON TUEDAY. FOR WEDNESDAY...DEEPER MIXING AND
LOW/MIDLEVEL TEMPS AT LEAST AS WARM AS TUESDAY SHOULD SUPPORT HIGHS IN MID
80S AREAWIDE...WHICH IS AOA WARMER MAV GUIDANCE AND NEAR OR ABOVE RECORD
VALUES FOR THE DATE. FOR MORE INFORMATION...PLEASE SEE CLIMO SECTION BELOW.
(THURSDAY THROUGH MONDAY)
A FAILRY POTENT COLD FRONT ATTENDANT FROM A SFC LOW TRAVELLING ACROSS
WI AND INTO CANADA WILL INCREASE CHANCES OF SHOWERS AND STORMS FROM
NW TO SE ACROSS THE AREA ON THURSDAY. WENT WITH A GFS/ECMWF BLEND REGARDING
FRONTAL PLACEMENT AND ASSOCIATED WEATHER ELEMENTS. FRONT LOOKS TO BE NEAR
KCOU-KUIN LINE BY 1800 UTC THURSDAY AND APRPOACHING KUNO-KSTL LINE BY 0000
UTC FRIDAY. WITH MOST OF AREA AHEAD OF FRONT FOR AT LEAST A GOOD PART OF THE
DAY...WENT AOA MEX GUIDANCE FOR HIGH TEMPERATURES.
SHOWERS AND STORMS LOOK TO BE ALONG/JUST AHEAD OF THE FRONT WITH
POST-FRONTAL...MORE STRATIFORM PRECIPITATION BEHIND FRONT IN PRESENCE OF
FRONTOGENETICAL FORCING. STILL LOOKS LIKE THERE IS AT LEAST SOME POTENTIAL
FOR SOME SEVERE STORMS WITH THE FRONT AS 30-50 KNOTS OF DEEP LAYER SHEAR
AND STEEP MIDLEVEL LAPSE RATES WILL EXIST. HOWEVER...FAIRLY WEAK SFC
CONVERGENCE ALONG FRONT AND ONLY MARGINAL INSTABILITY (500-1000 J/KG SBCAPE)
LOOK TO PRECLUDE A HIGHER THREAT AT THIS TIME.
BEHIND THE FRONT...MUCH COOLER TEMPERATUERS WILL BE IN THE OFFING WITH
HIGHS ONLY IN L/M 50S THROUGH THE WEEKEND. STILL QUITE A BIT OF UNCERTAINTY
FOR SUNDAY-MONDAY AS GFS/ECMWF HAVE FLIP-FLOPPED A FEW TIMES REGARDING
HOW DEEP THE TROUGH WILL BE CARVING OUT IN THE EASTERN THIRD OF THE COUNTRY
AND ITS POTENTIAL INTERACTION WITH WHAT IS NOW NAMED TROPICAL DEPRESSION 18
OUT IN CARIBBEAN SEA. TEMPERATURES MAY REBOUND A BIT FASTER THAN CURRENTLY
FORECAST IF FLOW IS MORE ZONAL ACROSS OUR REGION ALLOWING COLDER AIR TO STAY
FURTHER TO THE NORTH.
GOSSELIN
&&
.AVIATION...
ISSUED AT 1057 PM CDT MON OCT 22 2012
AN INITIAL BATCH OF SCATTERED SHOWERS WAS MOVING NEWD THROUGH COU
LATE THIS EVNG. A BETTER COVERAGE OF SHOWERS AND STORMS IS
EXPECTED LATE TGT AND TUE MRNG AHEAD OF A SHORTWAVE TROUGH NOW
OVER ERN PORTIONS OF KS AND OK WHICH WILL MOVE E-NEWD THROUGH MO
LATE TGT AND TUE MRNG. AN AREA OF SHOWERS AND THUNDERSTORMS MOVING
NEWD THROUGH SWRN MO SHOULD MOVE THROUGH OUR AREA LATE TGT AND
EARLY TUE MRNG. WILL INCLUDE VCTS IN THE TAFS AND A TEMPO GROUP OF
SHOWERS DURING THIS TIME PERIOD. THERE WILL BE PLENTY OF LOW-MID
LEVEL CLOUDS LATE TGT AND TUE MRNG BUT THIS SHOULD BE VFR OUTSIDE
OF SHOWERS/STORMS. SLY SFC WINDS WILL CONTINUE THIS FORECAST
PERIOD AS THE WARM FRONT HAS MOVED N OF THE TAF SITES. THERE MAY
BE SOME LLWS LATE TGT AND EARLY TUE MRNG BUT IT DOES NOT APPEAR
STRONG ENOUGH TO INCLUDE IN THE TAFS WITH THE SWLY LOW LEVEL JET
TRANSLATING NEWD THROUGH OR NEAR COU AND UIN LATE TGT AND EARLY
TUE MRNG. THE CLOUDS SHOULD SCATTER OUT TUE AFTN INTO TUE EVNG
WITH THE WARM FRONT WELL N OF OUR AREA AND THE SHORTWAVE E OF THE
REGION.
SPECIFICS FOR KSTL...THE SHOWERS AND STORMS ACROSS SWRN MO SHOULD
MOVE NEWD UP THE I-44 CORRIDOR AND INTO STL LATE TGT BY 08-09Z TUE.
WILL INCLUDE VCTS ALONG WITH A TEMPO GROUP OF SHOWERS AFTER THIS TIME.
THE SHOWERS AND STORMS SHOULD MOVE NE OF STL BY LATE TUE MRNG.
VFR LOW-MID LEVEL CLOUD CEILING SHOULD PREVAIL LATE TGT AND TUE
MRNG...THEN THE CLOUDS SHOULD SCATTER OUT TUE AFTN OR EARLY TUE
EVNG. SLY SFC WIND WILL CONTINUE LATE TGT AND INCREASE TO AROUND
13-14 KTS TUE AFTN...THEN WEAKEN TUE EVNG.
GKS
&&
.CLIMATE...
ISSUED AT 319 PM CDT SUN OCT 21 2012
RECORD HIGHS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
OCTOBER 23 86(1939) 91(1939) 86(1939)
OCTOBER 24 85(1940) 86(1940) 84(1940)
RECORD HIGH MINIMUMS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
OCTOBER 23 67(2010) 65(1963) 63(1991)
OCTOBER 24 66(1991) 65(1991) 65(1991)
OCTOBER 25 69(1939) 68(1939) 63(1963)
MILLER
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 83 63 86 66 / 60 5 0 10
QUINCY 83 62 83 64 / 20 10 5 10
COLUMBIA 86 64 86 65 / 20 10 0 10
JEFFERSON CITY 86 64 86 65 / 20 10 0 10
SALEM 80 62 83 62 / 60 5 0 5
FARMINGTON 82 59 83 59 / 60 5 0 5
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
410 AM CDT TUE OCT 23 2012
.DISCUSSION...
PRIMARY FOCUS THROUGH THIS FORECAST PERIOD IS FOG AND TEMPERATURES
TODAY...THEN RAIN/SNOW CHANCES FOCUSED ON WEDNESDAY NIGHT AND
THURSDAY. BEYOND THAT...COLDER TEMPERATURES FOR THE LATTER HALF OF
THE WEEK.
WATER VAPOR IMAGERY THIS MORNING SHOWS A LONGWAVE TROUGH OVER THE
EASTERN PACIFIC INTO THE WESTERN CONUS...WITH RIDGING ACROSS THE
GREAT LAKES. A WEAK SHORTWAVE TROUGH WAS OBSERVED ACROSS THE
NORTHERN PLAINS...WITH SUBSIDENCE ALOFT ACROSS NEBRASKA HELPING TO
KEEP THE MID-LEVELS DRY THIS MORNING. SEVERAL OTHER SHORTWAVES OF
NOTE WITHIN THE LONGWAVE TROUGH WERE ONE OVER NEVADA...WITH
ANOTHER STILL OVER THE OCEAN. AT THE SURFACE...SOUTH TO SOUTHEAST
FLOW WAS BRINGING IN LOW LEVEL MOISTURE AND WITH THE DRY AIR
ALOFT...FOG HAS DEVELOPED ACROSS ALMOST ALL OF NEBRASKA BY 08Z.
THIS HAS KEPT TEMPERATURES UP...WITH READINGS IN THE MID 40S TO
LOW 50S. THE OTHER FEATURE TO NOTE IS LOW PRESSURE ON THE LEE SIDE
OF THE ROCKIES.
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ACCORDING TO THE RUC AND THE NAM...FOG SHOULD SLOWLY DISSIPATE
FROM THE WEST...BUT PLACES OVER THE EASTERN PART OF THE FORECAST
AREA...EAST OF HIGHWAY 83 COULD SEE THE FOG LINGER INTO THE EARLY
AFTERNOON HOURS. THE FOG WILL HAVE A BIG IMPACT ON HIGH
TEMPERATURES TODAY SO IF IT FAILS TO DISSIPATE BY 18Z OR
19Z...TEMPERATURES COULD BE UP TO 10 DEGREES TO WARM IN PLACES.
DAY SHIFT WILL NEED TO MONITOR TRENDS IN CASE TEMPERATURE FORECAST
NEEDS TO BE MODIFIED. 850MB TEMPERATURES WILL INCREASE TODAY
/BETWEEN 15C AND 23C/ DUE TO WARM AIR ADVECTION AHEAD OF THE AREA
OF LOW PRESSURE TO THE WEST. ASSUMING SKIES CLEAR...TEMPERATURES
SHOULD WARM CONSIDERABLY...WITH LOW 80S POSSIBLE ACROSS SOUTHWEST
NEBRASKA. THE SHORTWAVE TROUGH OVER NEVADA WILL LIFT INTO MONTANA
TODAY...WHICH WILL GIVE THE FRONT TO THE WEST A BIT OF A PUSH
EASTWARD. THE NAM PUSHES A DRYLINE ACROSS THE SANDHILLS THIS
AFTERNOON...WHICH COULD DROP DEWPOINTS INTO THE LOW 30S. GOING
SOUTH...DEWPOINTS WILL DROP INTO THE 30S AS WELL AS THE DRYLINE
PROGRESSES EAST. THIS WILL PROMOTE DEEP MIXING TO NEAR 700MB.
WINDS THROUGH THE MIXED LAYER WILL BE STRONGEST ACROSS NORTHWEST
NEBRASKA...WHERE GUSTS TO 30 MPH LOOK POSSIBLE THIS AFTERNOON.
GOING SOUTH...WINDS ALOFT DECREASE SO WINDY CONDITIONS ARE NOT
EXPECTED. WITH THE TEMPERATURES EXPECTED TODAY...LOWEST RELATIVE
HUMIDITY WILL BE ACROSS SOUTHWEST NEBRASKA...WITH VALUES DROPPING
TO THE MID 20S WHERE WINDS WILL BE STRONG. AS IS
FORECAST...CRITICAL FIRE WEATHER CONDITIONS WILL NOT BE
MET...ALTHOUGH MARGINAL CONDITIONS WILL BE LIKELY IN A FEW
LOCATIONS FOR AT LEAST A FEW HOURS TODAY. AGAIN...CLOUD COVER
COULD HAMPER THIS FROM OCCURRING...SO WILL NEED TO MONITOR TRENDS
FOR POTENTIAL FIRE WEATHER ISSUES TODAY.
THE MONTANA WAVE LIFTS INTO CANADA TONIGHT...WITH A COLD FRONT TO
THE WEST PROGRESSING SOUTHEAST ACROSS NEBRASKA TONIGHT. BY MID
MORNING WEDNESDAY SHOULD BE THROUGH MOST OF THE FORECAST AREA.
COULD AGAIN SEE SOME FOG WEDNESDAY MORNING...BUT THIS SHOULD BE
CONFINED TO AREAS RIGHT ALONG AND BEHIND THE FRONT WHERE LOW LEVEL
MOISTURE POOLS. A THE SHORTWAVE TROUGH WILL ALSO MOVE ONLAND
TONIGHT...WHICH WILL THEN PROGRESS ACROSS UTAH AND INTO COLORADO
ON WEDNESDAY. AS THIS IS ONGOING...A 700MB TROUGH WILL PASS ACROSS
THE NORTHERN AND CENTRAL PLAINS WEDNESDAY AND WEDNESDAY NIGHT.
MODELS ARE SHOWING GOOD FRONTOGENETICAL FORCING...WHILE THE
LOCATION OF THE UPPER LEVEL JET STREAK PUTS NORTHWEST NEBRASKA IN
AN AREA OF GOOD LARGE-SCALE LIFT. THE SIGNAL HAS BEEN QUITE
CONSISTENT IN TIMING AND LOCATION OF THE BEST FORCING FROM THE
DIFFERENT MODELS OVER THE PAST FEW DAYS SO CONFIDENCE HAS
INCREASED IN GETTING PRECIPITATION ACROSS THE FORECAST AREA. IT
MAY TAKE A BIT OF TIME TO SATURATE THE LOW LEVELS...SO ONLY BEGAN
CHANCES FOR RAIN IN THE FAR NORTHERN PARTS OF SHERIDAN AND CHERRY
COUNTIES WEDNESDAY MORNING AND SLOWLY EXPANDING SOUTH THROUGH THE
AFTERNOON. WEDNESDAY EVENING LOOKS TO SEE THE BEST CHANCES FOR
PRECIPITATION IN AREAS NORTHWEST OF AN IMPERIAL TO VALENTINE
LINE...AND THOUGH DO HAVE RAIN CHANCES TO THE EAST...LOWERED
CHANCES BEFORE MIDNIGHT AS TOO MUCH DRY AIR LOOKS TO EXIST IN
THESE AREAS. THE PRECIPITATION AREA DOES SHIFT TO THE SOUTH AND
EAST AFTER MIDNIGHT...BUT AS THE PRIMARY SHORTWAVE TROUGH EXITS
THE AREA BY 12Z THURSDAY MORNING...LARGE-SCALE FORCING WILL
DETERIORATE SO CHANCES HAVE LOWERED FOR THURSDAY. BY LATE
AFTERNOON THURSDAY...EXPECT THE FORECAST AREA TO SEE PRIMARILY DRY
CONDITIONS. THERE IS ANOTHER SHORTWAVE THAT WILL ROUND THE
LONGWAVE TROUGH LATER THURSDAY AND THURSDAY NIGHT...BUT THE TREND
CONTINUES TO GO SOUTH SO PRECIPITATION CHANCES LOOK TO STAY TO THE
SOUTH. TEMPERATURE PROFILES CONTINUE TO SHOW THE PRECIPITATION
TYPE BEGIN AS RAIN...BUT CHANGE OVER TO A RAIN/SNOW MIX WITH SNOW
BECOMING THE DOMINANT TYPE ACROSS THE NORTHWEST AREAS AFTER
MIDNIGHT WEDNESDAY NIGHT. HAVE RAIN OR SNOW IN THE FORECAST ACROSS
THE ENTIRE AREA FOR THURSDAY MORNING AS THE PROFILES HUG 0C IN THE
LOWEST LEVELS ABOVE THE SURFACE. DON/T EXPECT MUCH ACCUMULATION OF
SNOW...WITH PRECIPITATION ACCUMULATIONS UP TO A THIRD OF AN INCH
MAINLY NORTH OF INTERSTATE 80.
.LONG TERM...FRIDAY THROUGH MONDAY
COLD TEMPERATURES WILL BE THE HIGHLIGHT FOR THE WEEKEND AS HIGHS
WILL BE HARD PRESSED TO MAKE IT OUT OF THE 30S AND 40S FOR FRIDAY
AND SATURDAY. LOWS ALSO WILL BE QUITE COLD...ALTHOUGH THE 23.00Z
MODEL SOLUTIONS ARE A BIT WARMER FOR BOTH FRIDAY AND SATURDAY
NIGHTS WITH THE SURFACE HIGH NOW LOOKING TO STAY OFF TO THE EAST
OF THE FORECAST AREA. LOWS SHOULD STILL EASILY DROP INTO THE
20S...WITH TEENS POSSIBLE FRIDAY NIGHT.
THE TREND NOW LOOKS FOR WARMER CONDITIONS GOING INTO NEXT WEEK AS
RIDGING BUILDS OVER THE WESTERN HALF OF THE COUNTRY. THIS WILL
BRING MILD TEMPERATURES BACK INTO THE CENTRAL PLAINS WITH 850MB
TEMPERATURES WARMING INTO THE TEENS AGAIN BY MONDAY...COMPARED TO
READINGS BELOW 0C WHICH WILL BE EXPERIENCED FRIDAY AND SATURDAY.
THE FORECAST IS DRY THROUGH THIS PERIOD AS THE LONGWAVE TROUGH
WILL PUSH THE MOISTURE ACROSS THE PLAINS WELL TO THE
SOUTHEAST.
&&
.AVIATION...
LIFR/IFR CIGS AND VSBY IMPROVE TO VFR FROM WEST TO EAST BETWEEN 15Z
AND 18Z ALONG AND WEST OF HIGHWAY 83. EAST OF HIGHWAY 83...LIFR/IFR
CIGS AND VIS IMPROVE TO IFR/MVFR CIGS AROUND 18Z AND THEN VFR BY 21Z.
A COLD FRONT WILL DROP INTO THE FCST AREA TONIGHT WITH MVFR/IFR CIGS
POSSIBLE AFTER 06Z TUESDAY NIGHT.
&&
.FIRE WEATHER...
POTENTIAL RED FLAG CONDITIONS WILL BE MONITORED ACROSS WRN NEB THIS
AFTERNOON DEPENDING ON THE PROGRESS OF A CLEARING LINE FCST TO
DEVELOP ACROSS THE PANHANDLE THIS MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
DISCUSSION...BROOKS
AVIATION/FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
318 AM CDT TUE OCT 23 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY...
LATEST WATER VAPOR IMAGERY SHOWS A LONG FETCH OF MOIST SOUTHWEST
FLOW WITH SEVERAL DISTURBANCES EJECTING OUT FROM AN UPPER LOW/LONG
WAVE TROUGH ANCHORED ALONG THE WEST COAST. THE NEXT PLUME OF
MOISTURE IS NOW EXPANDING OVER SOUTHEAST MONTANA AND THIS WILL
CONTINUE MOVING NORTHEAST THROUGH THE DAY. LATEST REGIONAL RADAR
SHOWS PERSISTENT RAIN IN THE NORTH CENTRAL UP TO THE NORTHERN
BORDER WITH SNOW IN THE FAR NORTHWEST. FURTHER SOUTH THE PRECIPITATION
WAS MORE RAGGED AND SCATTERED. A SURFACE LOW PRESSURE WILL MOVE
FROM NORTHEAST WYOMING ACROSS NORTHERN SOUTH DAKOTA TODAY WITH AN
INVERTED TROUGH REACHING INTO CENTRAL NORTH DAKOTA THIS AFTERNOON.
THE NAM/GFS ARE IN GOOD AGREEMENT WITH FRONTOGENESIS INITIATING IN
THE H85-H7 LAYER FROM AROUND GARRISON TO RUGBY AND INTO BOTTINEAU
TODAY. THIS AREA COINCIDES NICELY WITH A MAXIMUM IN THE OMEGA/LIFT
SIGNATURE PER GFS...BUT A LITTLE LESS ROBUST IN THE NAM. HOWEVER
BOTH MODELS ALONG WITH THE LATEST HRRR AGREE THAT THIS WILL BE THE
TARGET FOR HIGHEST POPS AND QPF. THUS WILL TAILOR THE NORTH
CENTRAL WITH NUMEROUS SHOWERS AND THEN TAPER THE WORDING FURTHER
SOUTH FROM SCATTERED TO ISOLATED. SOUTH CENTRAL NORTH DAKOTA WILL
BE IN THE WARM SECTOR PORTION OF THE LOW TODAY WITH HIGHS REACHING
THE MID 50S...AND MID 60S IN THE FAR SOUTHEAST. IT WILL REMAIN
COOL IN THE NORTH AND WEST WITH HIGHS IN THE MID TO UPPER 40S.
FOR TONIGHT INTO WEDNESDAY...WITH THE AFOREMENTIONED SURFACE LOW
EXITING THE AREA THIS EVENING...OUR ATTENTION TURNS TO THE NEXT
JET STREAK EJECTING INTO NORTH DAKOTA AFTER 06Z WEDNESDAY. THE
NAM/GFS BOTH SHOW FRONTOGENESIS IN THE ANOTHER H85-H65 LAYER
BEING INITIATED IN THE FAR SOUTH AND SOUTHEAST AFTER 06Z. THIS
BECOMES THE FOCUS FOR MORE PRECIPITATION AFTER 06Z WEDNESDAY AND
CONTINUING THROUGH THE DAY WEDNESDAY...WITH LIKELY POPS IN THE FAR
SOUTHEAST AND ISOLATED TO SCATTERED IN THE SOUTH. THE ONLY THREAT FOR
SNOW APPEARS DURING THE EARLY MORNING IN THE FAR SOUTHWEST WHERE
ISOLATED SNOW SHOWERS MAY DEVELOP WITH COLDER AIR ALREADY IN PLACE.
SOUNDINGS SUPPORT RAIN ELSEWHERE...ESPECIALLY WHERE THE POPS ARE
IN THE LIKELY CATEGORY IN THE FAR SOUTHEAST.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY.
MODELS IN GOOD AGREEMENT WITH BROAD TROUGH OVER CENTRAL NORTH
AMERICA THROUGH MOST OF THE PERIOD. CLOSED UPPER LOW CENTER MOVES
TO HUDSON BAY BY 00Z SATURDAY WITH NORTHWEST FLOW SETTING UP OVER
NORTHERN PLAINS AS MAIN TROUGH AXIS SHIFTS EAST. MAIN IMPACT ON
OUR AREA WILL BE BELOW NORMAL TEMPERATURES WITH HIGHS GENERALLY IN
THE 30S TO NEAR 40 ALONG SD BORDER AND LOWS IN THE 20S. OTHER THEN
A LOW CHANCE OF PRECIP WEDNESDAY NIGHT ACROSS THE SOUTH AS UPPER
WAVE ROTATES ACROSS THE REGION...MOSTLY DRY CONDITIONS ARE
EXPECTED UNTIL MONDAY WHEN A SYSTEM APPROACHES.
&&
.AVIATION...AS OF 08Z TAF LOCATIONS GENERALLY IN IFR TO LIFR
CATEGORY DUE TO LOW CEILINGS WITH EXCEPTION OF KJMS WHICH WAS STILL
MVFR. EXPECT SHOWERS CONTINUING INTO THE AFTERNOON...ENDING FROM
SOUTHWEST TO NORTHEAST. EXACT TIMING OF TRANSITION TO MVFR AND VFR
APPEARS TO BE AROUND 18Z FOR KDIK AND AFTER 21Z FOR
KISN...KMOT...KBIS AND KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM/AVIATION....JNS
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1110 PM CDT MON OCT 22 2012
.DISCUSSION.../ISSUED AT 1018 PM CDT/
FORECAST GENERALLY LOOKS IN GOOD SHAPE TONIGHT. EXPECT CLOUDY SKIES
TO PERSIST THROUGH THE NIGHT...WITH THE CLOUD DECK LOWERING BY
MORNING. AREAS OF DRIZZLE AND FOG SHOULD EXPAND LATER TONIGHT AS
WELL. TRICKY FORECAST FOR TUESDAY. SOME OF THE NEWER GUIDANCE IS
SUGGESTING CLOUDS WILL BE SLOWER TO ERODE THAN PREVIOUSLY FORECAST.
THUS DELAYED CLEARING SOME AND EXTENDED THE DRIZZLE AND FOG INTO MID
MORNING. WILL EVENTUALLY SEE CLEARING FROM WEST TO EAST THROUGH THE
AFTERNOON...WITH EXACT TIMING HAVING BIG IMPLICATIONS ON HIGH
TEMPERATURES. DECIDED TO LEAVE HIGH TEMPERATURE FORECAST AS IS FOR
NOW. BUT LATEST NAM AND RAP WOULD SUGGEST THE SLOWER EROSION OF
CLOUDS COULD KEEP HIGHS FIVE TO TEN DEGREES COOLER THAN CURRENT
FORECAST ALONG AND EAST OF INTERSTATE 29. MEANWHILE MOST SREF
MEMBERS ARE LESS AGGRESSIVE WITH THE COOLER TEMPERATURES. THUS WILL
LET MIDNIGHT SHIFT EVALUATE FURTHER AND MAKE NECESSARY ADJUSTMENTS.
/CHENARD
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
AVIATION FORECAST FOR THE TAF SITES CONTINUE TO SHOW BELOW NORMAL
CONFIDENCE IN THE DETAILS. CURRENTLY...CEILINGS ARE ALL OVER THE MAP
IN REGARDS TO CATEGORY...RANGING ANYWHERE FROM VFR TO IFR. MOST OF
THE IFR CEILINGS ARE BOTTLED UP IN PARTS OF SOUTHWEST MN. BUT ALONG
THE I 29 CORRIDOR...MANY OF THE LOWER CLOUDS HAVE SCATTERED OUT
CREATING VFR CONDITIONS...ONLY TO GO BACK TO MVFR IN THE JAMES RIVER
VALLEY AND POINTS WESTWARD. IN GENERAL...A WEAK WIND SHIFT TO THE
SOUTH WILL LIKELY EDGE NORTHWARD TO THE I 90 CORRIDOR BY DAYBREAK
TUESDAY. PLENTY OF IFR AND LIFR CONDITIONS EXIST IN EASTERN
NEBRASKA. THEREFORE CONTINUE TO BE WORRIED THAT A LOWERING OF
CEILINGS AND VISIBILITIES WILL BE IN STORE FOR OUR AREA LATE TONIGHT
AND EARLY TUESDAY WITH SOME LOCATIONS INTO THE IFR CATEGORY. ON
TUESDAY...THERE WILL BE CLEARING BUT WITH WIND SPEEDS NOT OVERLY
STRONG OUT OF THE SOUTH...THE CLEARING WILL LIKELY BE DELAYED UNTIL
THE AFTERNOON FOR MANY AREAS. IN ADDITION...THE NEXT COLD FRONT ALSO
LOOKS SLOWER SO BACKED OFF ON THE WIND SHIFT TO THE NORTHWEST
SEVERAL HOURS. /MJF
&&
.PREVIOUS DISCUSSION...
PRIMARY FORECAST CONCERNS ARE DRIZZLE/FOG SCENARIO TONIGHT...PRECIP
CHANCES MIDWEEK...THEN BELOW NORMAL TEMPERATURES INTO THE WEEKEND.
TONIGHT...FORECASTER CONFIDENCE: MODERATE.
A BROAD AREA OF LOW PRESSURE WILL DEVELOP OVER THE NRN PLAINS
AHEAD OF A SEASONABLY STRONG UPPER LEVEL TROUGH MOVING THROUGH THE
INTERMOUNTAIN WEST. ALTHOUGH LARGE SCALE ASCENT WILL BE RATHER
WEAK OVERNIGHT...THE COMBINATION OF PLENTIFUL BOUNDARY LAYER
MOISTURE /SPEC HUMIDITY AOA 8 G/KG/ AND WEAK LOW LEVEL LIFT IS
EXPECTED TO PRODUCE AREAS OF FOG/DRIZZLE OVER PORTIONS OF THE AREA.
NOT EXPECTING MUCH IN THE WAY OF QPF /MAYBE A COUPLE HUNDREDTHS/
HOWEVER DO BELIEVE A FEW AREAS ALONG AND EAST OF THE JAMES VALLEY
WILL SEE MEASURABLE RAINFALL. FOG MAY ALSO BE A CONCERN...BUT
DIFFICULT TO PINPOINT HOW DENSE IT MAY GET. FUTURE SHIFTS WILL HAVE
MONITOR VSBY TRENDS.
TUESDAY AND TUESDAY NIGHT...FORECAST CONFIDENCE: LOW TO MODERATE.
RESIDUAL STRATUS/FOG/DRIZZLE IS LIKELY EARLY TUESDAY
MORNING...BEFORE AN INCREASING S/SWLY LOW LEVEL FLOW GRADUALLY
NUDGES THE STRATUS DECK NORTH/EAST OF THE FORECAST AREA. MODELS CAN
STRUGGLE WITH THE EROSION/MOVEMENT OF STRATUS SO THERE IS SOME
UNCERTAINTY HOW QUICKLY CLOUDS MAY ERODE. ATTM...MODEL CONSENSUS
PUSHES HIGHER LOW LEVEL RH VALUES OUT BETWEEN 15-18Z TUE AND THIS
SEEMS REASONABLE. WILL CONTINUE TO BANK ON SEEING AT LEAST PARTLY
CLOUDY SKIES TUESDAY...WHICH WHEN COMBINED WITH H8 TEMPS +13 TO +18C
RANGE SHOULD ALLOW FOR VERY MILD TEMPS IN THE 70S TO NEAR 80F.
INCREASING CLOUDS ARE LIKELY TUESDAY NIGHT...BUT WILL MAINTAIN DRY
CONDITIONS FOR NOW.
WEDNESDAY THROUGH THURSDAY...FORECASTER CONFIDENCE: MODERATE TO HIGH.
UPPER TROUGH WILL MOVE SLOWLY ACROSS THE REGION BEGINNING ON
WEDNESDAY. STRONGEST UPPER LEVEL FORCING /Q-VECTOR CONVERGENCE AND
FGEN/ LOOKS TO REMAIN PRIMARILY NORTH OF THE AREA DURING THE DAY ON
WEDNESDAY...ALTHOUGH WILL MAINTAIN LOW POPS AS THERE IS SOME
UNCERTAINTY REGARDING TIMING OF PRECIPITATION. THE BRUNT OF
FORCING/SATURATION WILL AFFECT THE AREA ON WEDNESDAY NIGHT AND
EARLY THURSDAY DUE TO A COMBINATION OF UPPER LEVEL DIVERGENCE AND
A MODERATE MID-LEVEL FRONTOGENETIC ZONE. QPF AMOUNTS STILL A BIT
TRICKY TO PIN DOWN AT THIS TIMEFRAME...BUT MODEL CONSENSUS
INDICATES THAT 0.25"-0.50" IS POSSIBLE...WITH LOCALLY HIGHER
AMOUNTS. FROPA IS PROGGED TO BE A BIT QUICKER IN 12Z SUITE OF
MODELS...SO BEGAN TO TAPER PRECIP CHANCES SIGNIFICANTLY AFTER 18Z
THURSDAY. TEMPS SHOULD BE NEAR NORMAL WED...COOLING ON THURSDAY
BEHIND THE FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY...
SURFACE HIGH PRESSURE AND A COLD ARCTIC AIR AIRMASS WILL FILTER
INTO THE REGION LATE IN THE WEEK...RESULTING IN BELOW NORMAL
TEMPERATURES THROUGH THE REMAINDER OF THE LONG TERM PERIOD. ONLY
REAL CHANCES FOR PRECIPITATION WILL BE ASSOCIATED WITH ANOTHER
SERIES OF UPPER LEVEL DISTURBANCES WHICH WILL MOVE ACROSS THE
REGION OVER LATE THIS WEEKEND.
MF/KS
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
351 AM CDT TUE OCT 23 2012
.SHORT TERM...TODAY THROUGH THURSDAY
350 AM CDT TUE OCT 23 2012
AT 3 AM...A WARM FRONT EXTENDED FROM SIOUX CITY IOWA /KSUX/ TO
MUSCATINE IOWA /KMUT/. THERE IS LITTLE WEATHER ASSOCIATED WITH
THIS FRONT. MEANWHILE FURTHER NORTH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WERE DEVELOPING ALONG A BAND OF 900 TO 800 MB
FRONTOGENESIS ACROSS SOUTHEAST MINNESOTA. THE RUC SHOWS THAT THIS
BAND OF FRONTOGENESIS LIFTS QUICKLY NORTHEAST OF THE INTERSTATE 90
CORRIDOR AND BY LATE MORNING IT EXTENDS FROM HUDSON WISCONSIN TO
MILWAUKEE. THE MESO MODELS SEEM TO HAVE A FAIRLY GOOD HANDLE ON
THIS...SO FOLLOWED THEM. FURTHER SOUTHEAST...A SHORT WAVE TROUGH
WILL BE LIFTING NORTHEAST THROUGH THE MID MISSISSIPPI RIVER VALLEY
INTO THE LOWER GREAT LAKES. THERE IS MODERATE 850 MB MOISTURE INTO
PARTS OF OF NORTHEAST IOWA AND SOUTHWEST WISCONSIN THROUGHOUT THIS
MORNING...SO KEPT A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS
IN THESE AREAS THROUGHOUT THIS MORNING.
FOR THIS AFTERNOON...WEAK 300K ISENTROPIC LIFT CONTINUES NORTH OF
THE WARM FRONT NORTH OF THE INTERSTATE 94 CORRIDOR. AS A
RESULT...KEPT ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST
FOR THIS AREA.
FOR TONIGHT...THE 23.00Z MODELS ARE IN GENERAL AGREEMENT THAT
THERE WILL BE WEAK TO MODERATE 850 MOISTURE TRANSPORT INTO THE
REGION. THE MESO MODELS /ARW...NMM...AND SPC WRF/ SUGGEST THAT
THERE WILL BE SOME ISOLATED SHOWERS AND THUNDERSTORMS...SO KEPT
THE 20 PERCENT PROBABILITY OF RAIN ACROSS THE ENTIRE AREA.
ON WEDNESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT A WARM AIR
MASS BETWEEN 850 MB AND 675 MB WILL ADVECT NORTHWARD IN ADVANCE OF
AN APPROACHING COLD FRONT. THIS CAP SHOULD GREATLY INHIBIT THE
DEVELOPMENT OF PRECIPITATION AHEAD OF THE APPROACHING COLD FRONT
FOR MUCH OF THE DAY...THUS WENT DRY IN THE MORNING...AND SLOWLY
INCREASED THE PRECIPITATION CHANCES ACROSS NORTHEAST
IOWA...SOUTHEAST MINNESOTA...AND WEST-CENTRAL AND NORTH-CENTRAL
WISCONSIN. THINKING THAT THE STRONG CAP WILL LIMIT ANY SHOWER AND
THUNDERSTORM DEVELOPMENT TO ALONG AND JUST AHEAD OF THE COLD
FRONT. THE 0-6 KM BULK SHEAR IS FAVORABLE FOR THE DEVELOPMENT OF
SUPERCELL THUNDERSTORM DEVELOPMENT. THE GFS GENERATES SOME LIGHT
SHOWERS AHEAD OF THIS FRONT...THUS...ITS MLCAPES ARE RUNNING
BETWEEN 1000 AND 1500 J/KG. MEANWHILE THE NAM/WRF IS DRY AND
ALLOWS TEMPERATURES TO CLIMB TO AROUND 80. THE COMBINATION OF
THESE TEMPERATURES AND MID 60 DEW POINTS /HIGHEST THIS LATE IN THE
YEAR SINCE OCTOBER 26 2010/ WILL RESULT IN THE ML CAPES AROUND
2500 J/KG. INITIALLY THINKING THAT THE CONVECTION WILL START TO
DEVELOP ALONG THE FRONT BETWEEN 24.19 AND 24.21Z AS ELEVATED CELLS
AND THEN BECOME SURFACE BASED BETWEEN 24.21Z AND 25.00Z. THE NAM
HAS A WEAK LOW ALONG THIS FRONT WHICH HELPS INCREASE THE 0-1KM
BULK SHEAR WHICH MAY POSSIBLY RESULT IN ISOLATED TORNADOES ACROSS
NORTH-CENTRAL IOWA AND SOUTH-CENTRAL AND SOUTHEAST MINNESOTA.
OTHERWISE...THE MAIN SEVERE WEATHER THREATS WILL BE LARGE HAIL AND
DAMAGING WIND DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS
NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND WEST-CENTRAL WISCONSIN.
ON THURSDAY...THE MODELS STILL DIFFER ON THE TIMING OF THE FRONT.
THE GFS IS THE SLOWEST AND LINGER PRECIPITATION ACROSS THE ENTIRE
AREA THROUGH THE DAY. MEANWHILE THE GEM IS THE FASTEST AND HAS THE
AFTERNOON DRY. DUE TO THESE DIFFERENCES...DID NOT GET TOO FANCY
WITH TRYING TO TIME THE PRECIPITATION OUT OF THE AREA.
REGARDLESS...THE MOST NOTICEABLE FEATURE WILL BE THE RAPIDLY
FALLING TEMPERATURES IN THE WAKE OF THE FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
350 AM CDT TUE OCT 23 2012
ON THURSDAY NIGHT...THE MODELS WERE IN GOOD CONSENSUS THAT THE
PRECIPITATION WOULD BE ENDING ACROSS WESTERN WISCONSIN DURING THE
EVENING. AS A RESULT...CONFINED THE PRECIPITATION CHANCES TO THAT
TIME PERIOD.
ON MONDAY...THE 23.00Z GFS WAS VERY SIMILAR WITH ITS 22.18Z RUN AT
GENERATING SOME WARM AIR ADVECTION PRECIPITATION ACROSS THE AREA.
MEANWHILE THE ECMWF CONTINUE TO SHOW THAT THIS PRECIPITATION WILL
DRY UP AS IT HEADS INTO THE AREA. DUE TO THESE DIFFERENCES
MENTIONED A SLIGHT CHANCE OF PRECIPITATION NORTH OF AN OELWEIN
IOWA TO MEDFORD WISCONSIN LINE. THE PRECIPITATION HAS THE
POTENTIAL OF BEING A MIX OF RAIN AND SNOW IN THE EARLY MORNING.
HOWEVER SINCE IT WAS VERY UNCLEAR IT WAS EVEN GOING TO
OCCUR...JUST OPTED TO GO WITH RAIN FOR NOW.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1139 PM CDT MON OCT 22 2012
THE SURFACE LOW HAS MOVE NORTH INTO WESTERN IOWA THIS EVENING AND
THE TWO WARM FRONTS HAVE CONSOLIDATED INTO ONE AND IT EXTENDS
FROM THE LOW ALONG THE I80 CORRIDOR. ISENTROPIC UP GLIDE OVER THE
FRONT HAS SLOWLY BEEN BRINGING THE CEILINGS DOWN ACROSS THE AREA
WITH IFR CONDITIONS ALREADY IN PLACE AT KRST. AS THE FRONT MOVES
NORTH OVERNIGHT...EXPECT TO SEE THE IFR CONDITIONS MOVE SLOWLY
NORTH AS WELL AND SPREAD INTO KLSE. SOME DRIZZLE OCCURRING NORTH
OF THE WARM FRONT ALONG WITH SOME FOG AND EXPECT THESE WILL IMPACT
THE TAF SITES AS WELL. WITH THE HIGHER ELEVATION AT KRST...EXPECT
THAT THEY WILL GO DOWN TO LIFR CONDITIONS UNTIL THE WARM FRONT
GOES THROUGH. THE VALLEY LOCATION AT KLSE SHOULD PROTECT IT A
LITTLE MORE AND WHILE THE CEILINGS WILL GO IFR EXPECTING THE
VISIBILITY TO STAY MVFR. ONCE THE WARM FRONT GOES THROUGH TUESDAY
MORNING THE WINDS WILL SWING AROUND TO THE SOUTHEAST OR SOUTH AND
INCREASE THE MIXING. THE DRIZZLE WILL END WITH THE PASSAGE OF THE
FRONT AND EXPECT TO SEE IMPROVEMENTS IN BOTH THE VISIBILITY AND
CEILINGS. THE VISIBILITY SHOULD GO UP TO VFR BY EARLY AFTERNOON
BUT THE 23.00Z NAM HOLDS ON THE LOW LEVEL MOISTURE BEHIND THE
FRONT. SO SIMILAR TO THE PREVIOUS FORECASTS...WILL TREND TOWARD A
MORE PESSIMISTIC FORECAST BY KEEPING THE CEILINGS MVFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
350 AM CDT TUE OCT 23 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
928 AM MDT TUE OCT 23 2012
.UPDATE...A WEAK DISTURBANCE HAS CREATED SOME ISOLATED SNOW
SHOWERS OVER THE MOUNTAINS NEAR SUMMIT COUNTY THIS MORNING. HAVE
UPDATED THE GRIDS TO ADD MENTION OF THESE. ATMOSPHERE SEEMS TO BE
MIXING QUITE WELL ALREADY THIS MORNING AS WINDS ARE BECOMING GUSTY
OUT OF THE SOUTHWEST ALREADY OVER THE PALMER DIVIDE AND INTO THE
URBAN CORRIDOR.
&&
.AVIATION...WINDS WILL CONTINUE TO BE THE PROBLEM OF THE DAY
TODAY. STRONGER SOUTHWEST WINDS OVER THE PALMER DIVIDE ARE
OCCURRING AS THE BOUNDARY LAYER IS MIXING SOONER THAN FORECAST.
THESE ARE SPREADING INTO THE AREA AIRPORTS ALTHOUGH THERE IS A
NORTHWEST DIRECTION COMING OUT OF LARIMER...BOULDER AND WELD
COUNTIES. BELIEVE THE SOUTHWEST SHOULD BECOME PREVAILING SOON.
ADDED GUSTS INTO THE TAFS AS WELL. BOTH THE NAM AND THE GFS
CONTINUE TO SHOW A SWITCH TO WK NNELY FOR A FEW HOURS AROUND 00Z BEFORE
BECOMING MORE SSW AFTER 03Z. THIS COULD BE AN INITIAL SURGE AS THE
HRRR AND RUC ARE PICKING UP ON IT AS WELL. HOWEVER THE MAIN COLD
FRONT IS STILL EXPECTED TO MOVE INTO THE AREA BY 12Z WITH WINDS
BECOMING MORE NLY. LATEST SOUNDINGS SHOW SOME POTENTIAL FOR
3000-4000 FT BKN CEILINGS WED MORNING BETWEEN 12Z AND 16Z.
&&
.PREV DISCUSSION... /ISSUED 311 AM MDT TUE OCT 23 2012/
SHORT TERM...LOW CLOUDS AND FOG HAVE DEVELOPED OVER FAR NERN CO
EARLY THIS MORNING BUT SHOULD GRADUALLY BURN OFF AFTER 15Z. MEANWHILE
RATHER STG SWLY FLOW ALOFT WILL BE OVER THE AREA THRU TONIGHT AS
AN UPPER LEVEL LOW REMAINS OVER THE PACIFIC NW. SOME MOISTURE IS
EMBEDDED IN THIS FLOW AND WILL AFFECT MAINLY WRN AREAS OF JACKSON
COUNTY. THERE ARE SIGNIFICANT DIFFERENCES BETWEEN THE NAM AND GFS
WITH RESPECT TO PCPN CHANCES OVER ZN 31 TODAY AND TONIGHT AS THE
NAM IS DRIER WHILE THE GFS IS MUCH MORE WET. BASED ON POSITION OF
UPPER LEVEL JET APPEARS BEST CHC OF PCPN WOULD STAY NW OF ZN 31
HOWEVER WILL KEEP IN CHC POPS TODAY AND TONIGHT. ELSEWHERE WILL
KEEP FCST DRY. AS FAR AS HIGHS 850-700 MB TEMPS ARE SIMILAR TO SUN
HOWEVER LOW LEVEL FLOW EAST OF THE MTNS WILL BE MORE SWLY THIS
AFTN. THUS WOULD THINK HIGHS WOULD RISE INTO THE LOWER TO MID 70S
ACROSS MOST OF NERN CO. MEANWHILE AFTN HUMIDITY LEVELS OVER THE
PALMER DIVIDE DROP DOWN TO AROUND 15 PERCENT AND COMBINED WITH
GUSTY WSW WINDS COULD SEE RED FLAG CONDITIONS FOR A FEW HOURS IN
ZNS 46 AND 47.
FOR TONIGHT WILL CONTINUE TO SEE A CHC OF SHOWERS OVER ZN 31 BUT
WILL KEEP REST OF THE AREA DRY. A CDFNT WILL MOVE INTO NERN CO
AFTER MIDNIGHT WITH SOME POTENTIAL FOR LOW CLOUDS TO DVLP TOWARDS SUNRISE.
LONG TERM...OVERALL NO BIG CHANGES IN THE FORECAST WITH THE MAIN
AREA OF CONCERN IN THE WEDNESDAY TO FRIDAY WINDOW. THE MDLS HAVE A
STRONG SOUTHWESTERLY FLOW ALOFT OVER COLORADO ON WEDNESDAY WITH A
130KT UPPER LEVEL JET OVER WESTERN AND NORTHERN COLORADO AT 00Z
THURSDAY. THE NAM/GFS MDLS INDICATE WEAK TO MODERATE QG ASCENT
OVER THE CWFA WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. SEE NO
REASON TO ARGUE WITH THE LIKELY POPS IN THE GRIDS AT THIS TIME FOR
THE HIGH COUNTRY. SPATIAL CROSS-SECTIONS INDICATE THE AMS
SATURATING WEDNESDAY EVENING WITH UPSLOPE DEVELOPING TO AROUND 750
MB OVERNIGHT WITH A MOIST SWLY FLOW ALOFT OVERRUNNING THE AIRMASS.
NAM12 SPATIAL CROSS-SECTIONS ALSO INDICATE THE POTENTIAL FOR
BANDING ASSOCIATED WITH CONVECTIVE SYMMETRIC INSTABILITY OR C.S.I.
AREA THE THE GREATEST POTENTIAL FOR ACCUMULATING SNOWFALL WILL BE
NORTH OF INTERSTATE 70...ON THE COLDER SIDE OF THE UPPER JET SO
ZONES 31...33 AND 35 SHOULD DO THE BEST. BUT WITH BANDED BANDS
ZONES 30..32 AND 38 MAY ALSO SEE SOME DECENT SNOWFALL. WL ALSO
MENTION A SLIGHT CHANCE OF TSTMS WEDNESDAY AFTN/EVENING AS WELL.
WILL KEEP THE HIGHEST POPS/ACCUMULATION IN THESE AREA. ALTHOUGH
THE AMS WILL REMAIN SATURATED THURSDAY MORNING... INCREASING MID
LEVEL SUBSIDENCE SHOULD ALLOW FOR LIGHT SNOWFALL TO TAPER OFF BY
18Z THURSDAY. A SHORT WAVE RIDGE WILL BE OVER COLORADO BY THURSDAY
AFTN AHEAD OF ANOTHER WEAK SHORT WAVE DROPPING OUT OF THE NORTHERN
ROCKIES. THIS NEXT SYSTEM WILL DROP ACROSS NORTHERN COLORADO
AROUND 06Z FRIDAY BRINGING WITH IT ANOTHER SURGE OF COLD AIR ALONG
WITH ANOTHER CHANCE FOR SNOW. THIS SYSTEM MORE PROGRESSIVE AND
WITH NO UPSLOPE ASSOCIATED WITH IT AS THE SHORT WAVE BRUSHES
ACROSS THE CWFA. AS A RESULT...THE BEST CHC FOR PCPN MAY BE IN BE
IN THE NORTHERN MOUNTAINS AND FAR NORTHEAST PLAINS. IT IS STILL
PROGGED TO BE DRIER OVER THE WEEKEND. A STRONG NORTHWESTERLY FLOW
ALOFT WILL BE OVER THE STATE WITH JUST ENOUGH MOISTURE FOR A
SLIGHT CHANCE OF SNOW IN THE MOUNTAINS. TEMPERATURES WILL MODIFY
SOME BUT THEY WILL BE BELOW NORMAL THROUGH SATURDAY THROUGH
MONDAY.
AVIATION...WINDS EARLY THIS MORNING HAVE BEEN LIGHT SLY AND THE
HRRR KEEPS THEM THAT WAY THRU 18Z. BY EARLY AFTN THEY MAY BECOME
MORE SWLY AS MIXING OF THE BNDRY LAYER OCCURS. BY 00Z THE NAM
CONTINUES TO SHOW A SWITCH TO WK NNELY FOR A FEW HOURS BEFORE
BECOMING MORE SSW AFTER 03Z. OVERNIGHT A CDFNT WILL MOVE INTO THE
AREA BY 12Z WITH WINDS BECOMING MORE NLY. LATEST SOUNDINGS SHOW
SOME POTENTIAL FOR 3000-4000 FT BKN CEILINGS WED MORNING BETWEEN
12Z AND 16Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TODAY TO 6 PM MDT THIS EVENING FOR
COZ246-247.
&&
$$
SHORT TERM...RPK
LONG TERM....COOPER
UPDATE/AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS ALBANY NY
735 AM EDT TUE OCT 23 2012
.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTHWEST TODAY AND
TONIGHT...AS A WEAK WAVE OF LOW PRESSURE TRAVELS ALONG IT. THIS WILL
BRING CLOUDS AND SOME RAIN TO THE REGION THROUGH WEDNESDAY
MORNING...WITH THE BEST CHANCE OF RAIN EXPECTED FROM THE GREATER
CAPITAL REGION AND AREAS SOUTH AND WEST. TEMPERATURES WILL REMAIN
SOMEWHAT COOL DUE TO CLOUDS AND RAIN THROUGH WEDNESDAY...BEFORE
GRADUALLY WARMING FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 645 AM EDT...HIGH CLOUDS ARE GRADUALLY INCREASING ACROSS THE
REGION...WITH MID LEVEL CLOUDS SLOWLY APPROACHING FROM THE WEST.
TEMPS HAVE DROPPED INTO THE UPPER 30S TO LOWER 40S IN MOST
VALLEYS...WITH MID 30S ACROSS PORTIONS OF THE SOUTHERN ADIRONDACKS.
CLOUDS WILL CONTINUE TO INCREASE/THICKEN FROM W TO E THROUGH MID
MORNING. SOME SUNSHINE MAY BE DIMLY VISIBLE AT TIMES UNTIL
THEN...ESP FOR AREAS E OF THE HUDSON RIVER VALLEY...AND INTO
SOUTHERN VT.
AS ONE SHORTWAVE...CURRENTLY OVER LOWER MICHIGAN...TRANSLATES
EASTWARD TODAY...INCREASING ISENTROPIC LIFT TO THE EAST OF THIS
FEATURE SHOULD ALLOW RAIN TO EXPAND INTO WESTERN AND SOUTHERN
PORTIONS OF THE REGION BY MID TO LATE MORNING. 00Z/23 MODELS AND
03Z/SREFS HAVE TRENDED FURTHER NORTH WITH THE EXPECTED RAIN SHIELD
WITH THIS SYSTEM...AND THIS IS FURTHER SUPPORTED BY RECENT
UPSTREAM RADAR TRENDS...AS WELL AS THE LATEST HRRR MODEL.
THEREFORE...HAVE RAISED POPS INTO THE LIKELY RANGE FOR CENTRAL AND
SOUTHERN PORTIONS OF THE REGION...FOR THIS
AFTERNOON/EVENING...WITH THE NORTHERN EDGE OF LIKELY POPS JUST N
OF SARATOGA...AND INTO EXTREME SW VT. IT IS POSSIBLE THAT THIS
INITIAL SURGE OF RAINFALL WEAKENS A BIT UPON MOVING FURTHER E INTO
OUR REGION...AS IT OUTRUNS THE BEST LOW LEVEL MOISTURE TRANSPORT
CURRENTLY FEEDING INTO IT FROM THE OHIO VALLEY REGION.
HOWEVER...RENEWED SHOWERS/RAIN WILL LIKELY DEVELOP ON THE
NORTHERN PERIPHERY OF THE SHORTWAVE AS IT TRANSLATES NEAR OR JUST
S/W OF THE CAPITAL REGION LATER THIS AFTERNOON OR EARLY THIS
EVENING.
RAINFALL AMTS SHOULD BE GENERALLY LIGHT TO MODERATE...WITH AN AREA
OF ONE QUARTER...TO ONE HALF INCH EXPECTED JUST S/W OF THE CAPITAL
REGION...ACROSS THE SCHOHARIE VALLEY AND CATSKILLS. SOMEWHAT
HIGHER AMTS ARE POSSIBLE WITHIN ANY EMBEDDED BANDS THAT
DEVELOP...AS MID LEVEL FRONTOGENETICAL FORCING INCREASES LATER
THIS AFTERNOON. THEREFORE...HAVE INCLUDED A SMALLER AREA WITHIN
THE MORE GENERAL 0.25-0.50 REGION OF 0.50-0.75.
SOME WEAK ELEVATED INSTABILITY WILL PASS ACROSS SOUTHERN AREAS
LATER THIS AFTERNOON...WHICH COULD SUPPORT A FEW RUMBLES OF
THUNDER. HOWEVER...OVERALL ELEVATED INSTABILITY LOOKS MUCH WEAKER
THAN WHAT OCCURRED UPSTREAM DURING THE OVERNIGHT HOURS WHERE SOME
CG LIGHTNING STRIKES WERE NOTED. SO...HAVE KEPT OUT MENTION OF
THUNDER AT THIS TIME.
FOR TEMPS...GIVEN THE EXPECTED INCREASE IN CLOUD COVER AND
EVENTUAL RAIN...HAVE SIDED CLOSER TO THE COOLER MET MOS IN MOST
AREAS...WITH MID TO UPPER 50S EXPECTED FOR MAX TEMPS. GIVEN
INITIAL DEWPOINTS IN THE LOWER 40S...WET BULB COOLING MAY ACTUALLY
ALLOW TEMPS TO FALL ONCE THE RAIN DEVELOPS LATER THIS MORNING INTO
THE AFTERNOON. SHOULD THE RAIN DEVELOP ANY SOONER...EVEN COOLER
MAX TEMPS WOULD BE POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
TONIGHT...THE FIRST SHORTWAVE SHOULD TRANSLATE E/SE ACROSS THE
SOUTHERN HALF OF THE REGION THIS EVENING. THEN...A SECOND
SHORTWAVE SHOULD APPROACH SOUTHERN AREAS CLOSER TO DAYBREAK. THIS
SHOULD FAVOR SOUTHERN AREAS FOR THE BEST CHC FOR RAIN
OVERNIGHT...AFTER THE INITIAL SURGE OF LIGHT TO MODERATE RAINFALL
THIS EVENING. THEREFORE...WILL TREND LIKELY POPS SOUTHWARD THROUGH THE
EVENING AND OVERNIGHT HOURS. NORTHERN AREAS MAY ACTUALLY HAVE SOME
THIN SPOTS IN THE CLOUDS DEVELOP AT TIMES OVERNIGHT...WHICH COULD
ALLOW FOR COOLER TEMPS...AND SOME PATCHY FOG. HAVE GENERALLY SIDED
WITH A MAV/MET MOS BLEND...WHICH WERE FAIRLY CLOSE IN MOST AREAS.
WED-WED NT...MAIN FORCING MECHANISMS FOR LIFT SHOULD MOVE S AND E
OF REGION WED MORNING. IN THEIR WAKE...VERY LITTLE IN THE WAY OF
DYNAMICS WILL REMAIN. HOWEVER...LOW LEVEL MOISTURE AND WEAK LOW
LEVEL ISENTROPIC LIFT SHOULD PERSIST...AND MAY ACTUALLY INTENSIFY
WED NT. THEREFORE...WILL KEEP SOME SLIGHT CHC POPS FOR WED
AFTERNOON ACROSS SOUTHERN AREAS...THEN EXPAND POPS NORTHWARD...AND
INCLUDE CHC POPS ACROSS THE EASTERN CATSKILLS. THIS WILL BE FOR
LIGHT RAIN SHOWERS AND AREAS OF DRIZZLE IN THE PERSISTENT LOW
LEVEL ISENTROPIC LIFT...AND WELL AS FOR THE INTERACTION OF THE
HIGHER TERRAIN WITH THE MOIST AND LIGHT SE FLOW. FOR TEMPS...SIDED
CLOSER TO THE COOLER MET MOS AGAIN FOR WED...WITH MAINLY 55-60
EXPECTED IN MOST AREAS DUE TO CLOUDS AND SOME LIGHT RAIN/DRIZZLE.
FOR WED NT...SIDED CLOSER TO THE WARMER MET MOS...DUE TO EXPECTED
CLOUD COVER...WITH WIDESPREAD 40S TO LOWER 50S.
THU-THU NT...DESPITE STRONGLY RISING MID AND UPPER TROPOSPHERIC
HEIGHTS...A PERSISTENT MOIST SE FLOW MAY ACT TO KEEP LOW CLOUDS
AND SOME SPOTTY DRIZZLE FAIRLY PERSISTENT THROUGH THIS PERIOD. HAVE
THEREFORE SIDED CLOSER TO THE COOLER MET MOS...WITH GENERALLY
60-65 EXPECTED FOR MAXES...AND 40S TO LOWER 50S FOR MINS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
NOT A WHOLE LOT OF CHANGE TO THE LONG RANGE FORECAST WITH LOTS OF
SPREAD IN THE GUIDANCE AS TO HOW A POTENTIAL STORM ALONG THE EAST
COAST OF THE U.S EVOLVES. THE FIRST PART OF THE LONG RANGE
FORECAST...FRIDAY AND SATURDAY...LOOKS QUIET...WITH DRY WEATHER...
INCREASING CLOUD COVER AND HIGH TEMPERATURES IN THE 60S TO AROUND
70.
THERE COULD BE SOME ISOLATED SHOWERS ADVANCING INTO WESTERN
AREAS SATURDAY AFTERNOON DEPENDING ON THE TIMING OF THE APPROACH OF
A STRONG NORTHERN STREAM SYSTEM FROM THE MIDWEST AND GREAT LAKES.
THIS NORTHERN STREAM SYSTEM...COMBINED WITH HIGH AMPLITUDE UPPER
RIDGING JUST OFF THE CANADIAN COAST...IS PREDICTED TO INFLUENCE THE
MOVEMENT OF THE TROPICAL SYSTEM CURRENTLY DEVELOPING IN THE
CARIBBEAN.
DECENT CONSENSUS THAT THESE UPPER FEATURES WILL INTERACT WITH THE
TROPICAL SYSTEM...SUPPORTING NORTHWARD MOVEMENT. HOWEVER...THE EXACT
POSITION OF THESE STEERING FEATURES WILL DETERMINE WHETHER THE STORM
IMPACTS THE EASTERN U.S. OR STAYS MAINLY OUT TO SEA. SO...THE RANGE
OF POSSIBLE IMPACTS IS STILL ANYWHERE FROM NO IMPACT TO A
SIGNIFICANT IMPACT...BUT AN EXTREMELY UNUSUAL UPPER PATTERN
CONFIGURATION AND STORM TRACK WOULD BE REQUIRED FOR THE WORST CASE
SCENARIO OF HEAVY RAIN AND WINDS IN EASTERN AND NORTHERN NY AND
WESTERN NEW ENGLAND. STILL AT THE WAIT AND SEE STAGE FOR THIS
POTENTIAL SYSTEM...WHICH AGAIN COULD HAVE MINIMAL IMPACT OR
SIGNIFICANT IMPACT OR SOMETHING IN BETWEEN.
EVEN THE GUIDANCE THAT KEEPS THE STORM WELL OFFSHORE SHOWS OUR
REGION IN THE RIGHT ENTRANCE REGION OF A STRONG UPPER JET SEGMENT
AND DECENT BOUNDARY LAYER THERMAL GRADIENT ALONG A COLD FRONT...
ASSOCIATED WITH THE ADVANCING NORTHERN STREAM SYSTEM THAT COULD BE
GOING NEGATIVE TILT AND TRENDING TOWARD BECOMING A CUT OFF UPPER
LOW. SO EVEN IF WE DO NOT SEE A DIRECT IMPACT FROM THE STORM...SOME
ENHANCED RAINFALL ALONG THE COLD FRONT...AND WITHIN THE REGION OF
STRONG UPPER DYNAMICS...COULD OCCUR SATURDAY NIGHT THROUGH MONDAY.
JUST INDICATING CLOUDY WITH CHANCES OF RAIN SATURDAY NIGHT THROUGH
MONDAY WITH HIGHS IN THE MID 50S TO LOWER 60S SUNDAY AND UPPER 40S
TO MID 50S MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SOME HIGH THIN CLOUDS ARE SPREADING ACROSS THE REGION AHEAD OF AN
UPPER LEVEL SYSTEM IN THE GREAT LAKES AND VFR CONDITIONS SHOULD
PREVAIL THROUGH MUCH OF THIS MORNING. THE SYSTEM IN THE GREAT LAKES
SHOULD TRACK ACROSS OUR REGION THROUGH THE DAY AND EVENING. AN AREA
OF LIGHT RAIN CURRENTLY IN WESTERN NY IS TRACKING TOWARD EASTERN
NY. A FEW SHOWERS COULD BEGIN TO AFFECT TAF SITES BETWEEN 15Z-
17Z. ONCE THE RAIN STARTS AND BECOMES STEADY...IT SHOULD LAST
UNTIL AROUND 00Z-01Z. THE NORTHERN PERIPHERY OF THE STEADIER RAIN
SHOULD BE ABOUT KALB AND KPSF. HOWEVER...PUTTING VCSH IN KGFL.
SOME TEMPO MVFR CEILINGS AND VISIBILITIES ARE POSSIBLE DURING THE
RAIN AT KALB...KPSF AND POU THIS AFTERNOON AND EARLY EVENING. THE
EXACT END OF THE RAIN IS UNKNOWN BUT KEPT VCSH THROUGH 12Z AND
SOME MVFR CEILINGS AT ALL SITES UNTIL THE EXACT TIMING OF THE EXIT
OF THE RAIN IS KNOWN.
WINDS SHOULD BE LIGHT EAST TO NORTHEAST AT 5 KT OR LESS TROUGH THE
TAF PERIOD ENDING AT 06Z TOMORROW.
OUTLOOK...
WED...VFR/MVFR. CHC -SHRA ESPECIALLY SOUTH OF KALB.
THU-FRI...VFR. NO SIG WX.
SAT...VFR. SLGT CHC -SHRA.
&&
.FIRE WEATHER...
FIRE WEATHER RELATED CONCERNS SHOULD REMAIN MINIMAL OVER THE NEXT
3 DAYS DUE TO LIGHT WINDS AND PERSISTENT HIGH RELATIVE
HUMIDITIES. REFER TO LATEST FWFALY FOR MORE SPECIFIC DETAILS.
&&
.HYDROLOGY...
RAINFALL AMTS SHOULD GENERALLY BE ONE QUARTER...TO ONE HALF OF AN
INCH FOR AREAS NEAR AND TO THE SOUTH/WEST OF THE GREATER CAPITAL
REGION THROUGH THURSDAY...WITH LESS THAN ONE QUARTER OF AN INCH
TO THE NORTH AND EAST. SOME MINOR...WITHIN BANK RISES ARE POSSIBLE
FOR AREAS WHERE RAINFALL AMTS REACH ONE HALF INCH OR
GREATER...SUCH AS ON THE ESOPUS...RONDOUT AND SCHOHARIE CREEKS.
GENERALLY DRY CONDITIONS ARE EXPECTED FOR LATE THURSDAY THROUGH
AT LEAST EARLY SATURDAY.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...KL
HYDROLOGY...KL
AREA FORECAST DISCUSSION
NWS ALBANY NY
644 AM EDT TUE OCT 23 2012
.SYNOPSIS...
A WARM FRONT WILL APPROACH FROM THE SOUTHWEST TODAY AND
TONIGHT...AS A WEAK WAVE OF LOW PRESSURE TRAVELS ALONG IT. THIS WILL
BRING CLOUDS AND SOME RAIN TO THE REGION THROUGH WEDNESDAY
MORNING...WITH THE BEST CHANCE OF RAIN EXPECTED FROM THE GREATER
CAPITAL REGION AND AREAS SOUTH AND WEST. TEMPERATURES WILL REMAIN
SOMEWHAT COOL DUE TO CLOUDS AND RAIN THROUGH WEDNESDAY...BEFORE
GRADUALLY WARMING FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 645 AM EDT...HIGH CLOUDS ARE GRADUALLY INCREASING ACROSS THE
REGION...WITH MID LEVEL CLOUDS SLOWLY APPROACHING FROM THE WEST.
TEMPS HAVE DROPPED INTO THE UPPER 30S TO LOWER 40S IN MOST
VALLEYS...WITH MID 30S ACROSS PORTIONS OF THE SOUTHERN ADIRONDACKS.
CLOUDS WILL CONTINUE TO INCREASE/THICKEN FROM W TO E THROUGH MID
MORNING. SOME SUNSHINE MAY BE DIMLY VISIBLE AT TIMES UNTIL
THEN...ESP FOR AREAS E OF THE HUDSON RIVER VALLEY...AND INTO
SOUTHERN VT.
AS ONE SHORTWAVE...CURRENTLY OVER LOWER MICHIGAN...TRANSLATES
EASTWARD TODAY...INCREASING ISENTROPIC LIFT TO THE EAST OF THIS
FEATURE SHOULD ALLOW RAIN TO EXPAND INTO WESTERN AND SOUTHERN
PORTIONS OF THE REGION BY MID TO LATE MORNING. 00Z/23 MODELS AND
03Z/SREFS HAVE TRENDED FURTHER NORTH WITH THE EXPECTED RAIN SHIELD
WITH THIS SYSTEM...AND THIS IS FURTHER SUPPORTED BY RECENT
UPSTREAM RADAR TRENDS...AS WELL AS THE LATEST HRRR MODEL.
THEREFORE...HAVE RAISED POPS INTO THE LIKELY RANGE FOR CENTRAL AND
SOUTHERN PORTIONS OF THE REGION...FOR THIS
AFTERNOON/EVENING...WITH THE NORTHERN EDGE OF LIKELY POPS JUST N
OF SARATOGA...AND INTO EXTREME SW VT. IT IS POSSIBLE THAT THIS
INITIAL SURGE OF RAINFALL WEAKENS A BIT UPON MOVING FURTHER E INTO
OUR REGION...AS IT OUTRUNS THE BEST LOW LEVEL MOISTURE TRANSPORT
CURRENTLY FEEDING INTO IT FROM THE OHIO VALLEY REGION.
HOWEVER...RENEWED SHOWERS/RAIN WILL LIKELY DEVELOP ON THE
NORTHERN PERIPHERY OF THE SHORTWAVE AS IT TRANSLATES NEAR OR JUST
S/W OF THE CAPITAL REGION LATER THIS AFTERNOON OR EARLY THIS
EVENING.
RAINFALL AMTS SHOULD BE GENERALLY LIGHT TO MODERATE...WITH AN AREA
OF ONE QUARTER...TO ONE HALF INCH EXPECTED JUST S/W OF THE CAPITAL
REGION...ACROSS THE SCHOHARIE VALLEY AND CATSKILLS. SOMEWHAT
HIGHER AMTS ARE POSSIBLE WITHIN ANY EMBEDDED BANDS THAT
DEVELOP...AS MID LEVEL FRONTOGENETICAL FORCING INCREASES LATER
THIS AFTERNOON. THEREFORE...HAVE INCLUDED A SMALLER AREA WITHIN
THE MORE GENERAL 0.25-0.50 REGION OF 0.50-0.75.
SOME WEAK ELEVATED INSTABILITY WILL PASS ACROSS SOUTHERN AREAS
LATER THIS AFTERNOON...WHICH COULD SUPPORT A FEW RUMBLES OF
THUNDER. HOWEVER...OVERALL ELEVATED INSTABILITY LOOKS MUCH WEAKER
THAN WHAT OCCURRED UPSTREAM DURING THE OVERNIGHT HOURS WHERE SOME
CG LIGHTNING STRIKES WERE NOTED. SO...HAVE KEPT OUT MENTION OF
THUNDER AT THIS TIME.
FOR TEMPS...GIVEN THE EXPECTED INCREASE IN CLOUD COVER AND
EVENTUAL RAIN...HAVE SIDED CLOSER TO THE COOLER MET MOS IN MOST
AREAS...WITH MID TO UPPER 50S EXPECTED FOR MAX TEMPS. GIVEN
INITIAL DEWPOINTS IN THE LOWER 40S...WET BULB COOLING MAY ACTUALLY
ALLOW TEMPS TO FALL ONCE THE RAIN DEVELOPS LATER THIS MORNING INTO
THE AFTERNOON. SHOULD THE RAIN DEVELOP ANY SOONER...EVEN COOLER
MAX TEMPS WOULD BE POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
TONIGHT...THE FIRST SHORTWAVE SHOULD TRANSLATE E/SE ACROSS THE
SOUTHERN HALF OF THE REGION THIS EVENING. THEN...A SECOND
SHORTWAVE SHOULD APPROACH SOUTHERN AREAS CLOSER TO DAYBREAK. THIS
SHOULD FAVOR SOUTHERN AREAS FOR THE BEST CHC FOR RAIN
OVERNIGHT...AFTER THE INITIAL SURGE OF LIGHT TO MODERATE RAINFALL
THIS EVENING. THEREFORE...WILL TREND LIKELY POPS SOUTHWARD THROUGH THE
EVENING AND OVERNIGHT HOURS. NORTHERN AREAS MAY ACTUALLY HAVE SOME
THIN SPOTS IN THE CLOUDS DEVELOP AT TIMES OVERNIGHT...WHICH COULD
ALLOW FOR COOLER TEMPS...AND SOME PATCHY FOG. HAVE GENERALLY SIDED
WITH A MAV/MET MOS BLEND...WHICH WERE FAIRLY CLOSE IN MOST AREAS.
WED-WED NT...MAIN FORCING MECHANISMS FOR LIFT SHOULD MOVE S AND E
OF REGION WED MORNING. IN THEIR WAKE...VERY LITTLE IN THE WAY OF
DYNAMICS WILL REMAIN. HOWEVER...LOW LEVEL MOISTURE AND WEAK LOW
LEVEL ISENTROPIC LIFT SHOULD PERSIST...AND MAY ACTUALLY INTENSIFY
WED NT. THEREFORE...WILL KEEP SOME SLIGHT CHC POPS FOR WED
AFTERNOON ACROSS SOUTHERN AREAS...THEN EXPAND POPS NORTHWARD...AND
INCLUDE CHC POPS ACROSS THE EASTERN CATSKILLS. THIS WILL BE FOR
LIGHT RAIN SHOWERS AND AREAS OF DRIZZLE IN THE PERSISTENT LOW
LEVEL ISENTROPIC LIFT...AND WELL AS FOR THE INTERACTION OF THE
HIGHER TERRAIN WITH THE MOIST AND LIGHT SE FLOW. FOR TEMPS...SIDED
CLOSER TO THE COOLER MET MOS AGAIN FOR WED...WITH MAINLY 55-60
EXPECTED IN MOST AREAS DUE TO CLOUDS AND SOME LIGHT RAIN/DRIZZLE.
FOR WED NT...SIDED CLOSER TO THE WARMER MET MOS...DUE TO EXPECTED
CLOUD COVER...WITH WIDESPREAD 40S TO LOWER 50S.
THU-THU NT...DESPITE STRONGLY RISING MID AND UPPER TROPOSPHERIC
HEIGHTS...A PERSISTENT MOIST SE FLOW MAY ACT TO KEEP LOW CLOUDS
AND SOME SPOTTY DRIZZLE FAIRLY PERSISTENT THROUGH THIS PERIOD. HAVE
THEREFORE SIDED CLOSER TO THE COOLER MET MOS...WITH GENERALLY
60-65 EXPECTED FOR MAXES...AND 40S TO LOWER 50S FOR MINS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
NOT A WHOLE LOT OF CHANGE TO THE LONG RANGE FORECAST WITH LOTS OF
SPREAD IN THE GUIDANCE AS TO HOW A POTENTIAL STORM ALONG THE EAST
COAST OF THE U.S EVOLVES. THE FIRST PART OF THE LONG RANGE
FORECAST...FRIDAY AND SATURDAY...LOOKS QUIET...WITH DRY WEATHER...
INCREASING CLOUD COVER AND HIGH TEMPERATURES IN THE 60S TO AROUND
70.
THERE COULD BE SOME ISOLATED SHOWERS ADVANCING INTO WESTERN
AREAS SATURDAY AFTERNOON DEPENDING ON THE TIMING OF THE APPROACH OF
A STRONG NORTHERN STREAM SYSTEM FROM THE MIDWEST AND GREAT LAKES.
THIS NORTHERN STREAM SYSTEM...COMBINED WITH HIGH AMPLITUDE UPPER
RIDGING JUST OFF THE CANADIAN COAST...IS PREDICTED TO INFLUENCE THE
MOVEMENT OF THE TROPICAL SYSTEM CURRENTLY DEVELOPING IN THE
CARIBBEAN.
DECENT CONSENSUS THAT THESE UPPER FEATURES WILL INTERACT WITH THE
TROPICAL SYSTEM...SUPPORTING NORTHWARD MOVEMENT. HOWEVER...THE EXACT
POSITION OF THESE STEERING FEATURES WILL DETERMINE WHETHER THE STORM
IMPACTS THE EASTERN U.S. OR STAYS MAINLY OUT TO SEA. SO...THE RANGE
OF POSSIBLE IMPACTS IS STILL ANYWHERE FROM NO IMPACT TO A
SIGNIFICANT IMPACT...BUT AN EXTREMELY UNUSUAL UPPER PATTERN
CONFIGURATION AND STORM TRACK WOULD BE REQUIRED FOR THE WORST CASE
SCENARIO OF HEAVY RAIN AND WINDS IN EASTERN AND NORTHERN NY AND
WESTERN NEW ENGLAND. STILL AT THE WAIT AND SEE STAGE FOR THIS
POTENTIAL SYSTEM...WHICH AGAIN COULD HAVE MINIMAL IMPACT OR
SIGNIFICANT IMPACT OR SOMETHING IN BETWEEN.
EVEN THE GUIDANCE THAT KEEPS THE STORM WELL OFFSHORE SHOWS OUR
REGION IN THE RIGHT ENTRANCE REGION OF A STRONG UPPER JET SEGMENT
AND DECENT BOUNDARY LAYER THERMAL GRADIENT ALONG A COLD FRONT...
ASSOCIATED WITH THE ADVANCING NORTHERN STREAM SYSTEM THAT COULD BE
GOING NEGATIVE TILT AND TRENDING TOWARD BECOMING A CUT OFF UPPER
LOW. SO EVEN IF WE DO NOT SEE A DIRECT IMPACT FROM THE STORM...SOME
ENHANCED RAINFALL ALONG THE COLD FRONT...AND WITHIN THE REGION OF
STRONG UPPER DYNAMICS...COULD OCCUR SATURDAY NIGHT THROUGH MONDAY.
JUST INDICATING CLOUDY WITH CHANCES OF RAIN SATURDAY NIGHT THROUGH
MONDAY WITH HIGHS IN THE MID 50S TO LOWER 60S SUNDAY AND UPPER 40S
TO MID 50S MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SOME HIGH THIN CLOUDS ARE SPREADING ACROSS THE REGION AHEAD OF AN
UPPER LEVEL SYSTEM IN THE GREAT LAKES AND VFR CONDITIONS SHOULD
PREVAIL THROUGH THIS MORNING. THE SYSTEM IN THE GREAT LAKES
SHOULD TRACK ACROSS OUR REGION THROUGH THE DAY AND EVENING. AN
AREA OF LIGHT RAIN SHOULD TRACK ACROSS CENTRAL AND SOUTHERN AREAS
FROM ABOUT 17Z THROUGH ABOUT 01Z. THE NORTHERN PERIPHERY OF THE
STEADIER RAIN SHOULD BE ABOUT KALB AND KPSF. HOWEVER...PUTTING
VCSH IN KGFL. SOME TEMPO MVFR CEILINGS AND VISIBILITIES ARE
POSSIBLE DURING THE RAIN AT KALB...KPSF ANDK POU THIS AFTERNOON
ADN EARLY EVENING. THE EXACT END OF THE RAIN IS UNKNOWN BUT KEPT
VCSH THROUGH 06Z AT ALL SITES UNTIL THE EXACT TIMING OF THE EXIT
OF THE RAIN IS KNOWN.
WINDS SHOULD BE LIGHT EAST TO NORTHEAST AT 5 KT OR LESS TROUGH THE
TAF PERIOD ENDING AT 06Z TOMORROW.
OUTLOOK...
TUE...MAINLY VFR. CHANCES -SHRA INCREASING AS THE DAY PROGRESSES
WITH THE BEST CHANCE AT KPOU.
TUE NIGHT-WED...VFR/MVFR. CHC -SHRA ESPECIALLY SOUTH OF KALB.
THU-FRI...VFR. NO SIG WX.
SAT...VFR. SLGT CHC -SHRA.
&&
.FIRE WEATHER...
FIRE WEATHER RELATED CONCERNS SHOULD REMAIN MINIMAL OVER THE NEXT
3 DAYS DUE TO LIGHT WINDS AND PERSISTENT HIGH RELATIVE
HUMIDITIES. REFER TO LATEST FWFALY FOR MORE SPECIFIC DETAILS.
&&
.HYDROLOGY...
RAINFALL AMTS SHOULD GENERALLY BE ONE QUARTER...TO ONE HALF OF AN
INCH FOR AREAS NEAR AND TO THE SOUTH/WEST OF THE GREATER CAPITAL
REGION THROUGH THURSDAY...WITH LESS THAN ONE QUARTER OF AN INCH
TO THE NORTH AND EAST. SOME MINOR...WITHIN BANK RISES ARE POSSIBLE
FOR AREAS WHERE RAINFALL AMTS REACH ONE HALF INCH OR
GREATER...SUCH AS ON THE ESOPUS...RONDOUT AND SCHOHARIE CREEKS.
GENERALLY DRY CONDITIONS ARE EXPECTED FOR LATE THURSDAY THROUGH
AT LEAST EARLY SATURDAY.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...KL
HYDROLOGY...KL
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1036 AM CDT TUE OCT 23 2012
.DISCUSSION...
ISSUED 1036 AM CDT TUE OCT 23 2012
HAVE MADE TWEEKS TO TEMPS TODAY AND ADDED CHC POPS IN SOUTHEAST
FOR EARLY THIS AFTERNOON.
SHORTWAVE MOVING THROUGH AREA CURRENTLY IS ENHANCING PCPN
COVERAGE AND INTENSITY...PARTICULARLY SOUTHEAST HALF OF FORECAST
AREA. WAVE SHOULD MOVE PAST AREA EARLY THIS AFTERNOON AND
SHORTWAVE RIDGING SHOULD BUILD HEIGHTS AND ALLOW FOR SIGNIFICANT
SUBSIDENCE TO BRING AN END TO PCPN AND SOME BREAKS IN CLOUDS. THE
SLOWEST AREA OF IMPROVEMENT WILL LIKELY BE IN THE SOUTHEAST WHERE
REMNANT PCPN MAY LINGER AS AREA OF SHOWERS FORMED AT NOSE OF LOW-
LEVEL JET IN ERN MISSOURI MOVES EAST. ELSEWHERE...CAPPING SHOULD
INHIBIT ADDITIONAL DEVELOPMENT.
BREAKS IN CLOUDS SHOULD ALLOW TEMPS TO RESPOND. TEMPS ACROSS
SOUTHERN ILLINOIS ALREADY NEAR 70F AND WITH SOME SUN AND SOUTH
WINDS ADVECTING IN WARMER TEMPS...70S STILL LIKELY.
BARKER
&&
.AVIATION...
ISSUED 648 AM CDT TUE OCT 23 2012
WILL BE A BREAK IN THE PCPN THIS MORNING AS AREA WILL BE IN
BETWEEN COMPLEXES. THE NEXT ROUND OF PCPN SHOULD REACH SPI/PIA
AROUND 15Z...DEC/BMI AROUND 16Z AND THEN CMI AROUND 17Z. PCPN WILL
BE MAINLY SHOWERS BUT THUNDERSTORM ARE EMBEDDED IN THE COMPLEX SO
WILL ALSO HAVE A 2HR TEMPO GROUP FOR THUNDER AT EACH SITE DURING
THE LATE MORNING TO EARLY AFTERNOON. PCPN COULD LINGER BEHIND THE
MAIN AREA SO WILL BE KEEPING SHRA AND VCTS AT EACH SITE FOR COUPLE
HOURS AFTER TEMPO GROUP. ON BACK SIDE OF PCPN WINDS SHOULD ALSO
INCREASE SO WILL KEEP GUSTY WINDS DURING AFTERNOON. WINDS WILL BE
SOUTHERLY THROUGH THE PERIOD. CLOUDS WILL SCATTER OUT COUPLE OF
HOURS BEHIND THE SYSTEM AND THEN MOSTLY CLEAR AROUND SUNSET FOR
THE EVENING. NAM TRYING TO BRING SOME SC INTO THE AREA OVERNIGHT.
HOWEVER...UNSURE OF THIS SOLUTION SO WILL KEEP CLEAR FORECAST FOR
THE NIGHT HOURS FOR NOW.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 310 AM CDT TUE OCT 23 2012
WARM FRONT CURRENTLY LOCATED OVER NORTHERN ILLINOIS...ROUGHLY
ALONG THE I-80 CORRIDOR. HAVE BEEN SEEING SHOWERS AND STORMS
INCREASING ACROSS WESTERN ILLINOIS AND ESPECIALLY OVER
MISSOURI...AS AN UPPER WAVE MOVES INTO THE AREA AND AN APPARENT
MESOSCALE VORTEX TRACKS ACROSS MISSOURI PER WATER VAPOR IMAGERY.
INITIAL FORECAST CONCERN INVOLVES CONVECTIVE TRENDS FOR PRIMARILY
THIS MORNING...ALONG WITH ITS EFFECTS ON TEMPERATURES. IN THE
LONGER RANGE...THE TIMING OF A STRONG COLD FRONT ON THURSDAY
REMAINS AN ISSUE...ALONG WITH RAIN TRENDS THURSDAY AND FRIDAY.
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
LATEST HRRR DOING A REASONABLE JOB WITH THE CONVECTION OVER
MISSOURI...AND IT CONTINUES TO INCREASE THE RAIN OVER MOST OF THE
CWA THROUGH EARLY MORNING. AS SUCH...HAVE RAMPED UP RAIN CHANCES
TO THE LIKELY RANGE IN MOST AREAS...PRIMARILY ALONG AND EAST OF
I-55. ANY LINGERING RAIN SHOULD BE TAPERING OFF EARLY IN THE
AFTERNOON. THE CONVECTION YESTERDAY REALLY THREW OFF THE HIGH
TEMPERATURE FORECAST...AND WILL HAVE TO KEEP THAT POTENTIAL IN
MIND FOR TODAY...ESPECIALLY IF CLOUDS ARE SLOW TO MOVE OUT. HAVE
LOWERED HIGHS FOR TODAY BY A FEW DEGREES IN MOST AREAS...CLOSER TO
A MET/MAV BLEND. HOWEVER...HAVE KEPT HIGHS NEAR 80 DEGREES ON
WEDNESDAY AND OVER THE EASTERN 2/3 OF THE CWA ON THURSDAY AS WELL.
UPPER WAVE CURRENTLY OVER THE PACIFIC NORTHWEST IS EXPECTED TO
FORM A CLOSED LOW AS IT MOVES NORTHEAST TO THE CANADIAN PRAIRIES
BY EARLY WEDNESDAY. 50-70 KNOT JET AT 500 MB WILL FOLLOW A WAVE
SLIDING ALONG THE SOUTHERN JET STREAM TO FEED INTO THE AREA AHEAD
OF THE COLD FRONT. LATEST MODEL GUIDANCE BRINGS THE FRONT INTO THE
NORTHWESTERN CWA THURSDAY AFTERNOON...AND ENTERING THE SOUTHEAST
CWA TOWARD MIDNIGHT. A NARROW WINDOW OF OPPORTUNITY EXISTS FOR
SOME STRONGER STORMS AHEAD OF THE FRONT THURSDAY AFTERNOON...
ALTHOUGH RAPIDLY INCREASING CLOUDS MAY THWART THIS POTENTIAL.
HOWEVER...THE RAIN WILL BE ON THE INCREASE...AND HAVE INTRODUCED
LIKELY POPS NORTHWEST OF THE ILLINOIS RIVER DURING THE AFTERNOON.
WITH THE BULK OF THE RAIN BEHIND THE FRONT...WILL SPREAD THE
LIKELY POPS FROM WEST TO EAST...WITH THE RAIN DIMINISHING WEST OF
I-55 AFTER MIDNIGHT.
LONG TERM...FRIDAY THROUGH MONDAY...
MODELS HAVE BEEN BACKING OFF ON THE IDEA OF A SECONDARY WAVE
FEEDING THE AREA BEHIND THE FRONT...WITH THE 00Z ECMWF THE ONLY
ONE STILL WITH THIS GENERAL TREND. WILL DROP THE RAIN CHANCES
NORTHWEST OF THE ILLINOIS RIVER ON FRIDAY AND FRIDAY NIGHT...AND
LOWER THEM QUITE A BIT FURTHER EAST. HOWEVER...THE GFS AND
CANADIAN MODELS WOULD SUGGEST COMPLETELY DRY CONDITIONS BY EARLY
FRIDAY EVENING EVERYWHERE...SO WILL NEED TO SEE IF THIS TREND
CONTINUES. HAVE REMOVED THE RAIN ON SATURDAY ASIDE FROM SOME
SLIGHT CHANCES EAST OF I-57...MAINLY DURING THE MORNING.
WEEKEND TREND STILL LOOKS QUITE CHILLY...WITH HIGHS IN MANY AREAS
STRUGGLING TO REACH THE 50 DEGREE MARK. SUB-FREEZING LOWS ARE
EXPECTED ALONG AND WEST OF I-55 BY SUNDAY MORNING. BEYOND
THAT...THE FORECAST TRENDS BECOME COMPLICATED BY A TROPICAL SYSTEM
MOVING NORTHWARD OFF THE EAST COAST. ECMWF MODEL IS MORE AFFECTED
AND FORMS A CUTOFF LOW OVER THE GREAT LAKES...LINGERING THE CHILLY
WEATHER INTO EARLY NEXT WEEK...WHEREAS THE GFS IS MORE PROGRESSIVE
AND MILDER. NEITHER SOLUTION CURRENTLY YIELDS ANY PRECIPITATION
FOR OUR AREA SUNDAY AND MONDAY.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
944 AM CDT TUE OCT 23 2012
.DISCUSSION...
858 AM CDT
UPDATED GRIDS AND ZFP HAVE BEEN SENT WITH SIGNIFICANT CHANGES TO
FIRST PERIOD.
MORNING WATER VAPOR IMAGERY SHOWS A WELL DEFINED SHORTWAVE TROUGH
MOVING EASTWARD OVER IA/MO. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS LIKELY TO CONTINUE TO PERCOLATE IN THE VERY MOIST
AIRMASS OUT AHEAD OF THIS SHORTWAVE. MAJORITY OF THE ASCENT WITH
THIS WAVE SHOULD BE EAST OF THE CWA BY LATE AFTERNOON WITH SHOWER
AND THUNDERSTORM COVERAGE EXPECTED TO DECREASE TOWARD EVENING.
HAVE BUMPED UP SKY COVER CONSIDERABLY TODAY WITH NO HOPE OF SEEING
ANY BREAKS IN THE OVERCAST UNTIL THIS SHORTWAVE PASSES EAST OF THE
AREA LATE THIS AFTERNOON. EVEN THEN ONCE THE MID/HIGH LEVEL
MOISTURE CLEARS OUT THINKING ITS VERY LIKELY STRATUS DECK WILL
STICK AROUND AS OUR LATE OCTOBER SUN ANGLE IS ROUGHLY THE SAME AS
EARLY FEBRUARY AND WITH SUCH LATE CLEARING OF HIGH CLOUDS AND VERY
MOIST LOW LEVELS THINK IT WILL BE TOO LITTLE TOO LATE FOR THE SUN
TO EAT AWAY AT THE STRATUS. IN FACT...THERE IS A VERY REAL CHANCE
THAT STRATUS COULD STICK AROUND TONIGHT INTO TOMORROW MORNING AS
WELL AND HAVE BUMPED UP SKY GRIDS SOME TONIGHT. AFTERNOON FORECAST
MAY NEED TO CONSIDER ADJUSTING SKY COVER UP FURTHER TONIGHT INTO
TOMORROW.
GIVEN THE ANTICIPATED THICK OVERCAST MOST OF TODAY HAVE TAKEN A
HATCHET TO THE GOING HIGH TEMPERATURE FORECAST. GENERALLY WOULD
EXPECT TEMPS TO REMAIN NEARLY STEADY MOST OF THE DAY IN THE LOW TO
MID 60S...WITH A COUPLE/FEW DEGREE TEMP RISE POSSIBLE LATE THIS
AFTERNOON...ESPECIALLY FAR WESTERN CWA WHICH COULD POSSIBLY MAKE
A RUN AT 70 DEGREES STILL.
IZZI
//PREV DISCUSSION...
326 AM CDT
EARLY THIS MORNING THE FRONTAL BOUNDARY HAS STALLED ACROSS THE IL/WI
STATELINE. TO THE NORTH OF THE BOUNDARY TEMPS HAVE HELD IN THE
MID/UPR 50S WITH DEW PTS IN THE LOW/MID 50S WITH AREAS OF DENSE FOG.
SOUTH OF THE BOUNDARY TEMPS HAVE REMAINED VERY MILD FOR MID OCTOBER
IN THE 60S...ALONG WITH ANOMALOUSLY HIGH DEW PTS OF AROUND 60. IR
IMAGERY EARLY THIS MORNING DEPICTED THE LEADING EDGE OF HIGH BASED
CLOUDS FLOATING NORTH ALONG A CENTRAL IOWA...NORTHERN IL...TO FAR
SOUTHWEST LOWER MICHIGAN LINE. THIS AREA OF HIGH CLOUDS AND VERY
MOIST AIRMASS WAS ASSOCIATED WITH AN ELEVATED SHORTWAVE LIFTING
NORTHEAST ACROSS SOUTHWEST MISSOURI. SHOWERS AND THUNDERSTORMS HAVE
BEEN STEADILY GROWING IN COVERAGE ACROSS MISSOURI...AND BASED ON
CURRENT TRAJECTORIES THE LEADING PRECIP SHOULD ARRIVE ALONG THE
SOUTHWEST CWFA AROUND DAYBREAK. THEN STEADILY LIFT NORTHEAST ACROSS
THE REMAINING CWFA BY MID-MORNING. CURRENT GUIDANCE INDICATES CAPE
OF AROUND 500-750J/KG IN THE 15-18 TIMEFRAME...WHICH APPEARS TO BE
THE HIGHEST CONFIDENCE TIMING FOR CONVECTION TO OCCUR. SO HAVE
CARRIED LIKELY SHRA/TSRA AT THAT TIME.
AS THE ELEVATED WAVE ARRIVES ACROSS THE CWFA THIS MORNING...IT WILL
REMAIN PROGRESSIVE AND ALLOW PRECIP TO DIMINISH IN COVERAGE FROM
SOUTH TO NORTH ACROSS THE CWFA THIS AFTN. SUPPORTING THIS DRYING
TREND WILL BE THE SLOW RISE IN HEIGHTS ALOFT...INDICATING WEAK
DIFFLUENCE ALOFT.
WITH REGARDS TO TEMPS TODAY...GUIDANCE IS DEMONSTRATING A HIGHER
CONFIDENCE THAT TEMPS WILL EASILY WARM INTO THE 70S. THE CHALLENGE
IS DETERMINE THE LOCATIONS THAT WILL WARM INTO THE MID 70S...WHICH
CURRENTLY APPEARS TO BE ALONG AND SOUTH OF A ROCKFORD TO KANKAKEE
LINE. THE OTHER WILDCARD FOR LOCATIONS NORTH OF THIS LINE WILL BE
THE CLOUD COVER AND LINGERING PRECIP. AT THIS TIME IT APPEARS BY 21Z
ALL BUT A FEW SHRA SHOULD HAVE DEPARTED THE CWFA TO THE
NORTH...ALTHOUGH CLOUDS MAY STILL BE MOSTLY CLOUDY. PWAT VALUES WILL
REMAIN ABOVE 1 INCH THRU THE DAY TDY...WITH A HANDFUL OF LOCATIONS
RISING TO NEARLY 1.5 INCHES. THE COMBINATION OF MILD TEMPS AND HIGH
MOISTURE CONTENT IN THE ATMOSPHERE WILL MAKE TODAY AND WED FEEL MORE
LIKE SUMMER.
SOUTHERLY FLOW WILL LINGER THROUGH THE OVERNIGHT...AND SHOULD BE
JUST STRONG ENOUGH TO PREVENT DENSE FG FROM FORMING. THUS WILL ONLY
MENTION PATCHY FG IN THE FORECAST TONIGHT. ANOTHER MILD NIGHT
APPEARS LIKELY FOR TONIGHT WITH TEMPS ONLY COOLING INTO THE LOW 60S.
A FEW GUIDANCE MEMBERS WERE WARMER THAN THIS IN THE MID 60S AT A
HANDFUL OF POINTS...HOWEVER FELT THE GENERAL CONSENSUS WOULD BE
AROUND 60 TO PSBLY LOW 60S. DRY WEATHER SHOULD LAST THROUGH THE
OVERNIGHT HOURS AS WELL.
WEDNESDAY THROUGH THURSDAY...
500MB RIDGE PUSHES OVERHEAD WITH WEAK DIFFLUENT FLOW IN THE
LLVLS...SUGGESTING MUCH OF WED THRU AT LEAST DAYBREAK THUR WILL
REMAIN DRY. FOR WED THIS WILL SET THE STAGE FOR A RUN AT TEMPS
AROUND 80...PSBLY WARMING INTO THE LOW 80S FOR A FEW LOCATIONS WED
AFTN. THE DEEPER MOISTURE WILL PEEL OFF TO THE NORTHEAST WITH THE
WARM FRONTAL BOUNDARY...WHICH MAY AID IN SLIGHTLY LOWER DEW PTS AND
PWAT VALUES HOVER AROUND 1 INCH WED AFTN. IF DEW PTS CAN FALL INTO
THE MID/UPR 50S...THIS WOULD ALLOW THE SFC TO WARM MORE EFFICIENTLY
AND ALLOW THE SFC TO EASILY REACH 80 DEG IN MANY LOCATIONS OF THE
CWFA. CURRENT TEMP PLUMES FROM THE SREF AND VARIOUS OTHER GUIDANCE
SOURCES...INDICATE TEMPS WED WILL BE IN THE MID/UPR 70S OVER THE FAR
NORTHERN TIER OF COUNTIES IN IL. MEANWHILE FURTHER SOUTH OR SOUTH OF
I-88...TEMPS COULD WARM INTO THE UPR 70S TO AROUND 80. CLOUDS WILL
ALSO PLAY A ROLE...HOWEVER CURRENTLY FORECASTING P-CLOUDY CONDS WED.
THEN FOR THUR AHEAD OF THE FRONTAL BNDRY...TEMPS COULD WARM AGAIN
INTO THE MID/UPR 70S MAINLY FOR FAR EASTERN SECTIONS OF THE CWFA.
500MB TROUGH AXIS WILL BEGIN TO PUSH INTO THE CENTRAL PLAINS WED
NGT/EARLY THUR...WITH THE MAIN VORT MAX ROUNDING THE TROUGH AXIS
EARLY THUR MORNING ACROSS THE SOUTHERN PLAINS. IT APPEARS THAT THE
DOWNSTREAM RIDGE WILL EXTEND FROM QUEBEC TO THE CAROLINAS...WHICH
MAY ALLOW THE FRONTAL BNDRY TO SLOW SLIGHTLY. IF THE BNDRY SLOWS
FURTHER...PRECIP COULD REMAIN WEST OF THE CWFA THRU THE EARLY AFTN
HOURS AND ALLOW TEMPS TO BE EVEN WARMER...GIVEN THE POTENTIAL FOR
COMPRESSIONAL HEATING TO OCCUR BETWEEN THE DEPARTING SFC RIDGE AND
UPSTREAM TROUGH.
INSTABILITY WILL DEVELOP WITH THE PASSAGE THUR AFTN...THEN SHUD
STABILIZE IN THE EVENING HOURS WITH FRONTAL PASSAGE. WINDS WILL TURN
NW...WITH MUCH COOLER AIR STEADILY ADVECTING ACROSS THE CWFA.
THERMAL RIDGE OF 15 TO 17 DEG C AT 850MB RAPIDLY TRANSITIONS TO
AROUND 5 DEG C BY 06Z FRI.
FRIDAY THROUGH MONDAY...
POTENT ANTI-CYCLONIC FLOW QUICKLY ARRIVES FRI...AND SHUD PUSH THE
PRECIP/CLOUDS TO THE EAST ACROSS IN/MI. HOWEVER A FEW EASTERN AREAS
COULD CONTINUE TO SEE A SLIGHT CHC POPS FRI. FRI APPEARS TO BE THE
WARMEST DAY IN THE FINAL PERIODS OF THE EXTENDED...WITH TEMPS
EXPECTED TO BE IN THE LOW 50S. THESE HIGH TEMPS MAY ACTUALLY ARRIVE
EARLY IN THE DAY...AS COLD AIR CONTINUES TO POUR IN FROM THE
NORTHWEST THROUGHOUT THE DAY.
LAKE EFFECT CONDS DEVELOP AND BECOME OPTIMAL FRI NGT/SAT/SAT NGT FOR
THE FAVORED AREAS OF NORTHWEST IN. THERMAL TROUGH OVERHEAD WILL
CONTINUE TO COOL WITH 0 TO -3 DEG C AT 850MB POISED TO PUSH OVERHEAD
SAT/SUN. THUS IT APPEARS TEMPS WILL STRUGGLE TO WARM BEYOND THE
LOW/MID 40S. AT THIS TIME IT DOES NOT APPEAR CLOUDS WILL BE A MAJOR
PLAYER. IN ADDITION DRY WEATHER SHOULD REMAIN THRU THE BULK OF THE
EXTENDED...WITH THE EXCEPTION OF NORTHWEST IN. ANY LINGERING PRECIP
DURING THE NOCTURNAL HOURS FRI/SAT/SUN COULD BECOME MIXED WITH SOME
WET SNOW...AS TEMPS WILL BE COOLING INTO THE MID 30S EACH OF THESE
NIGHTS. SAT NGT COULD BE THE COOLEST DAY AS GUIDANCE HAS INDICATED
THE SFC RIDGE PUSHING OVER CENTRAL WI. THIS COULD ALLOW WINDS TO
DIMINISH AND CLOUDS TO REMAIN MINIMAL...ALLOWING FOR OPTIMAL
RADIATIONAL COOLING TO TAKE PLAY SAT NGT. IF THIS SCENARIO WERE TO
VERIFY...TEMPS COULD EASILY BOTTOMOUT IN THE UPR 20S ACROSS THE
CWFA.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LIFR/IFR REST OF MORNING INTO EARLY AFTERNOON.
* WIND GRADUALLY VEERING FROM E TO S LATE MORNING THROUGH EARLY
AFTERNOON.
* PERIODS OF -RA WITH LOCAL SHRA REST OF MORNING THROUGH EARLY
AFTERNOON.
TRS
//DISCUSSION...UPDATED 14Z...
TROUGH/WARM FRONT HAS NOT LIFTED NWRD AS SOON AS MODELS EARLIER
INDICATED AND EVEN LATEST AVAILABLE HI RES HRRR AND RAP PLACE IT
TOO FAR N NEAR/TO WI BORDER BY 15-16Z WHICH LOOKS TO BE A COUPLE
HRS TOO FAST. LIFR AND IFR EXPECTED TO PERSIST TIL BOUNDARY DOES
LIFT N PAST TERMINALS AND WINDS BECOME SRLY BTWN 17Z-19Z THEN
CIGS SHUD LIFT AND VSBYS IMPROVE.
BETWEEN AREA OF RA AND TS MOVING ENE OVER NRN IN AND ANOTHER AREA
OF MAINLY RA AND A FEW TS MOVING SLIGHTLY N OF E FM ERN MO ACROSS
THE MS RIVER ARE SCT DISORGANIZED -SHRA AND ISOLD SHRA. MODELS
SHOW BULK OF QPF E OF LOCAL TERMINALS BY 18Z AS UPPER TROUGH FROM
NRN MO SSE TO NERN AR MOVES OVER AND PAST THE LOCAL AREA. MODELS
DO INDICATE SPOTTY QPF 18Z-00Z BUT AMOUNTS OF ONLY A COUPLE
HUNDREDTHS OF AN INCH. DO NOT SEE ANY SIGNIFICANT FORCING
MECHANISMS FOR ADDITIONAL SHRA GENERATION BEYOND EARLY AFTERNOON.
TRS
PREVIOUS DISCUSSION...UPDATED 12Z...
TWO MAIN CONCERNS/CHALLENGES...CIGS AND TSRA THIS MORNING. LIFR
CIGS HAVE REMAINED LOCKED IN AND WITH CONTINUED LIGHT NORTHEAST
WINDS OFF THE LAKE...EXPECT AT LEAST A FEW MORE HOURS OF LIFR CIGS
UNTIL WINDS START TO TURN MORE SOUTHERLY AND CIGS LIFT. CONFIDENCE
REGARDING TIMING REMAINS LOW. ONCE CIGS DO LIFT...MVFR CIGS LIKELY
TO CONTINUE INTO THE EARLY/MID AFTERNOON.
ONE COMPLEX OF TSRA OVER EASTERN IL/WESTERN INDIANA WILL REMAIN
SOUTH OF THE TERMINALS WHILE CONVECTION OVER MISSOURI HAS WEAKENED
CONSIDERABLY IN THE PAST FEW HOURS. SHORT TERM GUIDANCE STILL
SUGGESTS FURTHER SHRA DEVELOPMENT ACROSS WESTERN IL THIS MORNING
BUT CONFIDENCE REGARDING TSRA POTENTIAL IS DECREASING AND TRENDS
WILL NEED TO BE MONITORED FOR POSSIBLE UPDATES.
SOUTHERLY WINDS MAY GUST INTO THE MID TEENS THIS AFTERNOON BUT
THIS WILL BE DEPENDENT ON SUNSHINE AND LOW LEVEL MIXING WHICH MAY
NOT OCCUR. SOUTHERLY WINDS WILL PERSIST TONIGHT AND SHOULD BEGIN
TO GUST SOME WEDNESDAY MORNING. WITH THE WARM FRONT EXPECTED TO BE
WELL NORTH OF THE AREA TONIGHT...NOT EXPECTING ANY WIDESPREAD FOG
OR LOW CIG PROBLEMS BUT HAVE INCLUDED SOME MVFR VIS AT RFD/DPA.
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE LIFR AND IFR CIGS WILL LIFT TO MVFR LATE
MORNING-EARLY AFTERNOON AND TO VFR EARLY-MID AFTERNOON.
* MEDIUM CONFIDENCE SCT -SHRA/ISOLD SHRA REST OF MORNING INTO
EARLY AFTERNOON.
* MEDIUM CONFIDENCE IN TIMING OF WINDS VEERING FM E TO S.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...VFR.
* THURSDAY...STRONG/GUSTY SOUTHWEST WINDS. SHRA/TSRA THURSDAY
AFTERNOON/EARLY EVENING...ALONG/AHEAD OF WIND SHIFT/COLD FRONT.
* FRIDAY AND SATURDAY...SLIGHT CHANCE OF SHRA.
* SUNDAY AND MONDAY...VFR.
&&
.MARINE...
308 AM...A FRONTAL BOUNDARY HAS BECOME NEARLY STATIONARY JUST
SOUTH OF LAKE MICHIGAN EARLY THIS MORNING. IT WILL BEGIN TO SLOWLY
LIFT NORTH LATER TODAY AND TONIGHT AS LOW PRESSURE OVER THE
NORTHERN PLAINS LIFTS NORTH INTO SOUTHERN CANADA. HOWEVER...WITH
HIGH PRESSURE ACROSS ONTARIO...THE GRADIENT WILL REMAIN FAIRLY
STRONG ACROSS THE NORTHERN THIRD OR QUARTER OF THE LAKE WITH
EASTERLY WINDS 15-25 KTS INTO TONIGHT...SLOWLY TURNING SOUTHEAST
AND WEAKENING BY WEDNESDAY MORNING. NEW LOW PRESSURE WILL DEVELOP
OVER EASTERN COLORADO TONIGHT AND MOVE NORTHEAST TO NEAR LAKE
SUPERIOR BY THURSDAY AFTERNOON. THE GRADIENT WILL STEADILY TIGHTEN
AHEAD OF THIS FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING BUT
FORECAST SOUNDINGS SHOW A FAIRLY STRONG MARINE LAYER/INVERSION.
BUT WINDS STILL EXPECTED TO REACH 30 KTS OR SO. WINDS WILL
DIMINISH AHEAD OF THE COLD FRONT LATE THURSDAY AFTERNOON/EARLY
THURSDAY EVENING THEN SHIFT OUT OF THE NORTHWEST BEHIND THE FRONT.
WITH HIGH PRESSURE BUILDING ACROSS THE PLAINS...THE GRADIENT
BEHIND THE FRONT WILL LIKELY SUPPORT GUSTS TO 30 KTS. COULD BE AN
HOUR OR TWO OF HIGHER GUSTS WITH/JUST BEHIND THE FRONT.
LIGHT WINDS ACROSS THE SOUTHERN TWO THIRDS OF THE LAKE...COMBINED
WITH THE VERY MOIST LOW LEVELS WILL LIKELY LEAD TO AREAS OF FOG
AND MAYBE SOME PATCHY DENSE FOG...THIS MORNING WHICH SHOULD
IMPROVE AS WINDS TURN MORE SOUTHERLY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
648 AM CDT TUE OCT 23 2012
.DISCUSSION...
ISSUED 310 AM CDT TUE OCT 23 2012
WARM FRONT CURRENTLY LOCATED OVER NORTHERN ILLINOIS...ROUGHLY
ALONG THE I-80 CORRIDOR. HAVE BEEN SEEING SHOWERS AND STORMS
INCREASING ACROSS WESTERN ILLINOIS AND ESPECIALLY OVER
MISSOURI...AS AN UPPER WAVE MOVES INTO THE AREA AND AN APPARENT
MESOSCALE VORTEX TRACKS ACROSS MISSOURI PER WATER VAPOR IMAGERY.
INITIAL FORECAST CONCERN INVOLVES CONVECTIVE TRENDS FOR PRIMARILY
THIS MORNING...ALONG WITH ITS EFFECTS ON TEMPERATURES. IN THE
LONGER RANGE...THE TIMING OF A STRONG COLD FRONT ON THURSDAY
REMAINS AN ISSUE...ALONG WITH RAIN TRENDS THURSDAY AND FRIDAY.
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
LATEST HRRR DOING A REASONABLE JOB WITH THE CONVECTION OVER
MISSOURI...AND IT CONTINUES TO INCREASE THE RAIN OVER MOST OF THE
CWA THROUGH EARLY MORNING. AS SUCH...HAVE RAMPED UP RAIN CHANCES
TO THE LIKELY RANGE IN MOST AREAS...PRIMARILY ALONG AND EAST OF
I-55. ANY LINGERING RAIN SHOULD BE TAPERING OFF EARLY IN THE
AFTERNOON. THE CONVECTION YESTERDAY REALLY THREW OFF THE HIGH
TEMPERATURE FORECAST...AND WILL HAVE TO KEEP THAT POTENTIAL IN
MIND FOR TODAY...ESPECIALLY IF CLOUDS ARE SLOW TO MOVE OUT. HAVE
LOWERED HIGHS FOR TODAY BY A FEW DEGREES IN MOST AREAS...CLOSER TO
A MET/MAV BLEND. HOWEVER...HAVE KEPT HIGHS NEAR 80 DEGREES ON
WEDNESDAY AND OVER THE EASTERN 2/3 OF THE CWA ON THURSDAY AS WELL.
UPPER WAVE CURRENTLY OVER THE PACIFIC NORTHWEST IS EXPECTED TO
FORM A CLOSED LOW AS IT MOVES NORTHEAST TO THE CANADIAN PRAIRIES
BY EARLY WEDNESDAY. 50-70 KNOT JET AT 500 MB WILL FOLLOW A WAVE
SLIDING ALONG THE SOUTHERN JET STREAM TO FEED INTO THE AREA AHEAD
OF THE COLD FRONT. LATEST MODEL GUIDANCE BRINGS THE FRONT INTO THE
NORTHWESTERN CWA THURSDAY AFTERNOON...AND ENTERING THE SOUTHEAST
CWA TOWARD MIDNIGHT. A NARROW WINDOW OF OPPORTUNITY EXISTS FOR
SOME STRONGER STORMS AHEAD OF THE FRONT THURSDAY AFTERNOON...
ALTHOUGH RAPIDLY INCREASING CLOUDS MAY THWART THIS POTENTIAL.
HOWEVER...THE RAIN WILL BE ON THE INCREASE...AND HAVE INTRODUCED
LIKELY POPS NORTHWEST OF THE ILLINOIS RIVER DURING THE AFTERNOON.
WITH THE BULK OF THE RAIN BEHIND THE FRONT...WILL SPREAD THE
LIKELY POPS FROM WEST TO EAST...WITH THE RAIN DIMINISHING WEST OF
I-55 AFTER MIDNIGHT.
LONG TERM...FRIDAY THROUGH MONDAY...
MODELS HAVE BEEN BACKING OFF ON THE IDEA OF A SECONDARY WAVE
FEEDING THE AREA BEHIND THE FRONT...WITH THE 00Z ECMWF THE ONLY
ONE STILL WITH THIS GENERAL TREND. WILL DROP THE RAIN CHANCES
NORTHWEST OF THE ILLINOIS RIVER ON FRIDAY AND FRIDAY NIGHT...AND
LOWER THEM QUITE A BIT FURTHER EAST. HOWEVER...THE GFS AND
CANADIAN MODELS WOULD SUGGEST COMPLETELY DRY CONDITIONS BY EARLY
FRIDAY EVENING EVERYWHERE...SO WILL NEED TO SEE IF THIS TREND
CONTINUES. HAVE REMOVED THE RAIN ON SATURDAY ASIDE FROM SOME
SLIGHT CHANCES EAST OF I-57...MAINLY DURING THE MORNING.
WEEKEND TREND STILL LOOKS QUITE CHILLY...WITH HIGHS IN MANY AREAS
STRUGGLING TO REACH THE 50 DEGREE MARK. SUB-FREEZING LOWS ARE
EXPECTED ALONG AND WEST OF I-55 BY SUNDAY MORNING. BEYOND
THAT...THE FORECAST TRENDS BECOME COMPLICATED BY A TROPICAL SYSTEM
MOVING NORTHWARD OFF THE EAST COAST. ECMWF MODEL IS MORE AFFECTED
AND FORMS A CUTOFF LOW OVER THE GREAT LAKES...LINGERING THE CHILLY
WEATHER INTO EARLY NEXT WEEK...WHEREAS THE GFS IS MORE PROGRESSIVE
AND MILDER. NEITHER SOLUTION CURRENTLY YIELDS ANY PRECIPITATION
FOR OUR AREA SUNDAY AND MONDAY.
GEELHART
&&
.AVIATION...
ISSUED 648 AM CDT TUE OCT 23 2012
WILL BE A BREAK IN THE PCPN THIS MORNING AS AREA WILL BE IN
BETWEEN COMPLEXES. THE NEXT ROUND OF PCPN SHOULD REACH SPI/PIA
AROUND 15Z...DEC/BMI AROUND 16Z AND THEN CMI AROUND 17Z. PCPN WILL
BE MAINLY SHOWERS BUT THUNDERSTORM ARE EMBEDDED IN THE COMPLEX SO
WILL ALSO HAVE A 2HR TEMPO GROUP FOR THUNDER AT EACH SITE DURING
THE LATE MORNING TO EARLY AFTERNOON. PCPN COULD LINGER BEHIND THE
MAIN AREA SO WILL BE KEEPING SHRA AND VCTS AT EACH SITE FOR COUPLE
HOURS AFTER TEMPO GROUP. ON BACK SIDE OF PCPN WINDS SHOULD ALSO
INCREASE SO WILL KEEP GUSTY WINDS DURING AFTERNOON. WINDS WILL BE
SOUTHERLY THROUGH THE PERIOD. CLOUDS WILL SCATTER OUT COUPLE OF
HOURS BEHIND THE SYSTEM AND THEN MOSTLY CLEAR AROUND SUNSET FOR
THE EVENING. NAM TRYING TO BRING SOME SC INTO THE AREA OVERNIGHT.
HOWEVER...UNSURE OF THIS SOLUTION SO WILL KEEP CLEAR FORECAST FOR
THE NIGHT HOURS FOR NOW.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
647 AM CDT TUE OCT 23 2012
.SHORT TERM...
ISSUED AT 214 AM CDT TUE OCT 23 2012
(TODAY AND TONIGHT)
FOCUS WILL ONCE AGAIN BE TSRA CHANCES TODAY...TURNING TO TEMPS ONCE
PRECIP HAS ENDED.
ONGOING TSRA JUST W OF THE CWA IS ANTICIPATED TO CONTINUE TO MOVE
ENE THRU THE CWA TODAY. THE 23/04Z HRRR AND 23/00Z 4KM NCEP WRF ARE
IN GOOD AGREEMENT AND HANDLE THE ONGOING SITUATION RATHER WELL. PLAN
IS TO CLOSELY FOLLOW THESE MDLS FOR POPS TODAY...PROVIDED THIS TREND
CONTINUES. THESE MDLS...AS WELL AS THE OPERATIONAL MDLS...ARE IN
GOOD AGREEMENT WITH PRECIP ENDING BY EARLY AFTERNOON AT THE LATEST
AS THE S/W WILL BE NEARING THE IL/IN BOARDER BY 21Z.
WITH PRECIP COMING TO AN END AND CLOUDS CLEARING THRU THE
AFTERNOON...AMPLE INSOLATION SHUD BE AVAILABLE FOR A QUICK WARM UP
TODAY. MADE ONLY MINOR CHANGES TO THE GOING FORECAST FOR TEMPS TODAY
AND TONIGHT. RAISED TEMPS A COUPLE OF DEGREES ACROSS CNTL MO AS
850MB TEMPS SHUD BE NEARING 18C ACCORDING TO THE NAM. WHILE THIS IS
A WARM OUTLIER AMONG THE 00Z GUIDANCE...THIS SOLN SEEMS PROBABLE
GIVEN THE WARM 850MB TEMPS ADVECTING NEWD BEHIND THIS S/W. THAT
SAID...MDL SOUNDINGS FOR TODAY SUGGEST MUCH OF THE REGION WILL NOT
MIX TO 850MB AND HAVE THEREFORE TRENDED TWD THE WARMER
GUIDANCE...BUT REMAINED JUST UNDER ACROSS CNTL MO. SIMILAR TRENDS
CONTINUE TONIGHT WITH SLY TO SWLY WINDS WILL REMAIN AOA 7 KTS.
TILLY
&&
.LONG TERM...
ISSUED AT 349 AM CDT TUE OCT 23 2012
(WEDNESDAY THROUGH THURSDAY)
ONCE THE S/W RESPONSIBLE FOR THE ONGOING TSRA MOVES E OF THE
AREA...THE SHORT TERM IS EXPECTED TO REMAIN DRY UNTIL THURS. MDLS
ARE IN RELATIVELY GOOD AGREEMENT UNTIL WED NIGHT. THE GFS SUGGESTS A
REINFORCING S/W ROUNDING THE BASE OF THE UPPER LOW WHICH HELPS TO
SPEED UP FROPA THURS NIGHT. HAVE TRENDED TWD THE CONSENSUS OF THE
OTHER MDLS...BUT KEPT CHANCE POPS TO ACCOUNT FOR THE FASTER GFS
SOLN.
UNTIL THURS...FOCUS REMAINS TEMPS. NOT MUCH HAS CHANGED WITH THE
23/00Z GUIDANCE AND SAW NO REASON TO MAKE MANY CHANGES TO THE GOING
FORECAST. OVERALL...CONTINUED TREND GOING AOA WARMEST GUIDANCE.
(FRIDAY THROUGH MONDAY)
MDL TRENDS DO NOT CHANGE MUCH EARLY IN THE EXTD PERIOD. THE 22/18Z
DGEX DEVELOPS AN AMPLIFIED TROF WITH THE SYSTEM AFFECTING THE CWA AT
THE BEGINNING OF THE PERIOD AND CONTINUES TO DEEPEN THIS TROF THRU
THE WEEKEND. THIS SOLN IS AN OUTLIER AMONG THE OPERATIONAL
MDLS...EVEN AMONG THE GEFS...AND HAVE TRENDED TWD THE OTHER
OPERATIONAL MDLS THRU THE PERIOD.
THE GEM BEGINS TO SPEED UP TO COME INTO BETTER AGREEMENT WITH THE
GFS LATE FRI INTO SAT. HAVE THEREFORE TRENDED TWD THESE SOLNS
REGARDING POPS LOWERING POPS FRI NIGHT ACROSS NWRN PORTIONS OF THE
CWA AND KEPT SAT DRY. REMAINDER OF THE EXTD IS DRY FOR NOW...BUT
MDLS SUGGEST A COUPLE OF S/WS THAT MAY BRING PRECIP ACROSS NRN
PORTIONS OF THE CWA LATE IN THE EXTD PERIOD.
AS FOR TEMPS...MDLS ARE IN RELATIVELY GOOD AGREEMENT EARLY IN THE
PERIOD...LARGE DIFFERENCES BEGIN BY SUN AND PROVIDE A VARIETY OF
SOLNS THRU THE PERIOD. HAVE TRENDED TWD A COMPROMISE OF THE
GFS/ECMWF/GEM FOR FRI. WITH UNCERTAINTY GROWING THRU THE EXTD...HAVE
TRENDED TWD A BLEND OF THE GFS/ECMWF BEYOND FRI AS THESE SOLNS
REMAIN SOMEWHAT CLOSE.
TILLY
&&
.AVIATION...
ISSUED AT 628 AM CDT TUE OCT 23 2012
A LARGE AREA OF RAIN WITH SOME EMBEDDED THUNDERSTORMS OVER CENTRAL
AND EASTERN MO WILL CONTINUE TO PROGRESS EASTWARD AND IMPACT THE
TAFS SITES DURING THE MORNING HOURS. OBSERVATIONS DURING THE
OVERNIGHT HOURS WITHIN THE RAIN AREA SUGGESTS MUCH OF THE RAIN
WILL OCCUR WITH VFR CONDITIONS OCCASIONALLY LOWERING TO MVFR WITH
SOME OF THE EMBEDDED THUNDER. ENDING OF THE PRECIPITATION IS A
LITTLE UNCERTAIN. THERE CONTINUE TO BE NEW CELLS DEVELOPING IN
WEST CENTRAL MO ON THE BACK EDGE. AT THIS TIME I HAVE ENDED
PRECITATION AT KUIN AND THE ST LOUIS AREA TAF SITES AT 16Z BUT IT
COULD BE A LITTLE LATER. AFTER THE PRECIPATION ENDS...VFR
CONDITIONS SHOULD PREVIAL WITH DECREASING CLOUDS.
SPECIFICS FOR KSTL...
LIGHT RAIN SHOULD BEGIN WITH THE NEXT HOUR AND CONTINUE THROUGH
LATE MORNING. UPSTREAM OBSERVATIONS OVERNIGHT SUGGESTS MUCH OF
THE RAIN WILL OCCUR WITH VFR CONDITIONS OCCASIONALLY LOWERING TO
MVFR WITH SOME OF THE EMBEDDED THUNDER. ENDING OF THE PRECIPITATION
IS A LITTLE UNCERTAIN. AT THIS TIME I HAVE ENDED PRECITATION AT
16Z BUT IT COULD BE A LITTLE LATER. AFTER THE PRECIPATION
ENDS...VFR CONDITIONS SHOULD PREVIAL WITH DECREASING CLOUDS.
GLASS
&&
.CLIMATE...
ISSUED AT 319 PM CDT SUN OCT 21 2012
RECORD HIGHS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
OCTOBER 23 86(1939) 91(1939) 86(1939)
OCTOBER 24 85(1940) 86(1940) 84(1940)
RECORD HIGH MINIMUMS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
OCTOBER 23 67(2010) 65(1963) 63(1991)
OCTOBER 24 66(1991) 65(1991) 65(1991)
OCTOBER 25 69(1939) 68(1939) 63(1963)
MILLER
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 83 63 86 66 / 80 5 0 10
QUINCY 83 62 83 64 / 60 10 5 10
COLUMBIA 86 64 86 65 / 60 10 0 10
JEFFERSON CITY 86 64 86 65 / 70 10 0 10
SALEM 80 62 83 62 / 80 5 0 5
FARMINGTON 82 59 83 59 / 80 5 0 5
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
633 AM CDT TUE OCT 23 2012
.UPDATE...
.AVIATION...
LIFR/IFR CIGS AND VSBY IMPROVE TO VFR FROM WEST TO EAST BETWEEN 15Z
AND 18Z ALONG AND WEST OF HIGHWAY 83. EAST OF HIGHWAY 83...LIFR/IFR
CIGS AND VIS IMPROVE TO IFR/MVFR CIGS AROUND 18Z AND THEN VFR BY 21Z.
A COLD FRONT WILL DROP INTO THE FCST AREA TONIGHT. A NARROW AREA
OF MVFR/IFR CIGS MAY DEVELOP POSSIBLE AFTER 09Z TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 410 AM CDT TUE OCT 23 2012/
DISCUSSION...
PRIMARY FOCUS THROUGH THIS FORECAST PERIOD IS FOG AND TEMPERATURES
TODAY...THEN RAIN/SNOW CHANCES FOCUSED ON WEDNESDAY NIGHT AND
THURSDAY. BEYOND THAT...COLDER TEMPERATURES FOR THE LATTER HALF OF
THE WEEK.
WATER VAPOR IMAGERY THIS MORNING SHOWS A LONGWAVE TROUGH OVER THE
EASTERN PACIFIC INTO THE WESTERN CONUS...WITH RIDGING ACROSS THE
GREAT LAKES. A WEAK SHORTWAVE TROUGH WAS OBSERVED ACROSS THE
NORTHERN PLAINS...WITH SUBSIDENCE ALOFT ACROSS NEBRASKA HELPING TO
KEEP THE MID-LEVELS DRY THIS MORNING. SEVERAL OTHER SHORTWAVES OF
NOTE WITHIN THE LONGWAVE TROUGH WERE ONE OVER NEVADA...WITH
ANOTHER STILL OVER THE OCEAN. AT THE SURFACE...SOUTH TO SOUTHEAST
FLOW WAS BRINGING IN LOW LEVEL MOISTURE AND WITH THE DRY AIR
ALOFT...FOG HAS DEVELOPED ACROSS ALMOST ALL OF NEBRASKA BY 08Z.
THIS HAS KEPT TEMPERATURES UP...WITH READINGS IN THE MID 40S TO
LOW 50S. THE OTHER FEATURE TO NOTE IS LOW PRESSURE ON THE LEE SIDE
OF THE ROCKIES.
SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ACCORDING TO THE RUC AND THE NAM...FOG SHOULD SLOWLY DISSIPATE
FROM THE WEST...BUT PLACES OVER THE EASTERN PART OF THE FORECAST
AREA...EAST OF HIGHWAY 83 COULD SEE THE FOG LINGER INTO THE EARLY
AFTERNOON HOURS. THE FOG WILL HAVE A BIG IMPACT ON HIGH
TEMPERATURES TODAY SO IF IT FAILS TO DISSIPATE BY 18Z OR
19Z...TEMPERATURES COULD BE UP TO 10 DEGREES TO WARM IN PLACES.
DAY SHIFT WILL NEED TO MONITOR TRENDS IN CASE TEMPERATURE FORECAST
NEEDS TO BE MODIFIED. 850MB TEMPERATURES WILL INCREASE TODAY
/BETWEEN 15C AND 23C/ DUE TO WARM AIR ADVECTION AHEAD OF THE AREA
OF LOW PRESSURE TO THE WEST. ASSUMING SKIES CLEAR...TEMPERATURES
SHOULD WARM CONSIDERABLY...WITH LOW 80S POSSIBLE ACROSS SOUTHWEST
NEBRASKA. THE SHORTWAVE TROUGH OVER NEVADA WILL LIFT INTO MONTANA
TODAY...WHICH WILL GIVE THE FRONT TO THE WEST A BIT OF A PUSH
EASTWARD. THE NAM PUSHES A DRYLINE ACROSS THE SANDHILLS THIS
AFTERNOON...WHICH COULD DROP DEWPOINTS INTO THE LOW 30S. GOING
SOUTH...DEWPOINTS WILL DROP INTO THE 30S AS WELL AS THE DRYLINE
PROGRESSES EAST. THIS WILL PROMOTE DEEP MIXING TO NEAR 700MB.
WINDS THROUGH THE MIXED LAYER WILL BE STRONGEST ACROSS NORTHWEST
NEBRASKA...WHERE GUSTS TO 30 MPH LOOK POSSIBLE THIS AFTERNOON.
GOING SOUTH...WINDS ALOFT DECREASE SO WINDY CONDITIONS ARE NOT
EXPECTED. WITH THE TEMPERATURES EXPECTED TODAY...LOWEST RELATIVE
HUMIDITY WILL BE ACROSS SOUTHWEST NEBRASKA...WITH VALUES DROPPING
TO THE MID 20S WHERE WINDS WILL BE STRONG. AS IS
FORECAST...CRITICAL FIRE WEATHER CONDITIONS WILL NOT BE
MET...ALTHOUGH MARGINAL CONDITIONS WILL BE LIKELY IN A FEW
LOCATIONS FOR AT LEAST A FEW HOURS TODAY. AGAIN...CLOUD COVER
COULD HAMPER THIS FROM OCCURRING...SO WILL NEED TO MONITOR TRENDS
FOR POTENTIAL FIRE WEATHER ISSUES TODAY.
THE MONTANA WAVE LIFTS INTO CANADA TONIGHT...WITH A COLD FRONT TO
THE WEST PROGRESSING SOUTHEAST ACROSS NEBRASKA TONIGHT. BY MID
MORNING WEDNESDAY SHOULD BE THROUGH MOST OF THE FORECAST AREA.
COULD AGAIN SEE SOME FOG WEDNESDAY MORNING...BUT THIS SHOULD BE
CONFINED TO AREAS RIGHT ALONG AND BEHIND THE FRONT WHERE LOW LEVEL
MOISTURE POOLS. A THE SHORTWAVE TROUGH WILL ALSO MOVE ONLAND
TONIGHT...WHICH WILL THEN PROGRESS ACROSS UTAH AND INTO COLORADO
ON WEDNESDAY. AS THIS IS ONGOING...A 700MB TROUGH WILL PASS ACROSS
THE NORTHERN AND CENTRAL PLAINS WEDNESDAY AND WEDNESDAY NIGHT.
MODELS ARE SHOWING GOOD FRONTOGENETICAL FORCING...WHILE THE
LOCATION OF THE UPPER LEVEL JET STREAK PUTS NORTHWEST NEBRASKA IN
AN AREA OF GOOD LARGE-SCALE LIFT. THE SIGNAL HAS BEEN QUITE
CONSISTENT IN TIMING AND LOCATION OF THE BEST FORCING FROM THE
DIFFERENT MODELS OVER THE PAST FEW DAYS SO CONFIDENCE HAS
INCREASED IN GETTING PRECIPITATION ACROSS THE FORECAST AREA. IT
MAY TAKE A BIT OF TIME TO SATURATE THE LOW LEVELS...SO ONLY BEGAN
CHANCES FOR RAIN IN THE FAR NORTHERN PARTS OF SHERIDAN AND CHERRY
COUNTIES WEDNESDAY MORNING AND SLOWLY EXPANDING SOUTH THROUGH THE
AFTERNOON. WEDNESDAY EVENING LOOKS TO SEE THE BEST CHANCES FOR
PRECIPITATION IN AREAS NORTHWEST OF AN IMPERIAL TO VALENTINE
LINE...AND THOUGH DO HAVE RAIN CHANCES TO THE EAST...LOWERED
CHANCES BEFORE MIDNIGHT AS TOO MUCH DRY AIR LOOKS TO EXIST IN
THESE AREAS. THE PRECIPITATION AREA DOES SHIFT TO THE SOUTH AND
EAST AFTER MIDNIGHT...BUT AS THE PRIMARY SHORTWAVE TROUGH EXITS
THE AREA BY 12Z THURSDAY MORNING...LARGE-SCALE FORCING WILL
DETERIORATE SO CHANCES HAVE LOWERED FOR THURSDAY. BY LATE
AFTERNOON THURSDAY...EXPECT THE FORECAST AREA TO SEE PRIMARILY DRY
CONDITIONS. THERE IS ANOTHER SHORTWAVE THAT WILL ROUND THE
LONGWAVE TROUGH LATER THURSDAY AND THURSDAY NIGHT...BUT THE TREND
CONTINUES TO GO SOUTH SO PRECIPITATION CHANCES LOOK TO STAY TO THE
SOUTH. TEMPERATURE PROFILES CONTINUE TO SHOW THE PRECIPITATION
TYPE BEGIN AS RAIN...BUT CHANGE OVER TO A RAIN/SNOW MIX WITH SNOW
BECOMING THE DOMINANT TYPE ACROSS THE NORTHWEST AREAS AFTER
MIDNIGHT WEDNESDAY NIGHT. HAVE RAIN OR SNOW IN THE FORECAST ACROSS
THE ENTIRE AREA FOR THURSDAY MORNING AS THE PROFILES HUG 0C IN THE
LOWEST LEVELS ABOVE THE SURFACE. DON/T EXPECT MUCH ACCUMULATION OF
SNOW...WITH PRECIPITATION ACCUMULATIONS UP TO A THIRD OF AN INCH
MAINLY NORTH OF INTERSTATE 80.
LONG TERM...FRIDAY THROUGH MONDAY
COLD TEMPERATURES WILL BE THE HIGHLIGHT FOR THE WEEKEND AS HIGHS
WILL BE HARD PRESSED TO MAKE IT OUT OF THE 30S AND 40S FOR FRIDAY
AND SATURDAY. LOWS ALSO WILL BE QUITE COLD...ALTHOUGH THE 23.00Z
MODEL SOLUTIONS ARE A BIT WARMER FOR BOTH FRIDAY AND SATURDAY
NIGHTS WITH THE SURFACE HIGH NOW LOOKING TO STAY OFF TO THE EAST
OF THE FORECAST AREA. LOWS SHOULD STILL EASILY DROP INTO THE
20S...WITH TEENS POSSIBLE FRIDAY NIGHT.
THE TREND NOW LOOKS FOR WARMER CONDITIONS GOING INTO NEXT WEEK AS
RIDGING BUILDS OVER THE WESTERN HALF OF THE COUNTRY. THIS WILL
BRING MILD TEMPERATURES BACK INTO THE CENTRAL PLAINS WITH 850MB
TEMPERATURES WARMING INTO THE TEENS AGAIN BY MONDAY...COMPARED TO
READINGS BELOW 0C WHICH WILL BE EXPERIENCED FRIDAY AND SATURDAY.
THE FORECAST IS DRY THROUGH THIS PERIOD AS THE LONGWAVE TROUGH
WILL PUSH THE MOISTURE ACROSS THE PLAINS WELL TO THE
SOUTHEAST.
AVIATION...
LIFR/IFR CIGS AND VSBY IMPROVE TO VFR FROM WEST TO EAST BETWEEN 15Z
AND 18Z ALONG AND WEST OF HIGHWAY 83. EAST OF HIGHWAY 83...LIFR/IFR
CIGS AND VIS IMPROVE TO IFR/MVFR CIGS AROUND 18Z AND THEN VFR BY 21Z.
A COLD FRONT WILL DROP INTO THE FCST AREA TONIGHT WITH MVFR/IFR CIGS
POSSIBLE AFTER 06Z TUESDAY NIGHT.
FIRE WEATHER...
POTENTIAL RED FLAG CONDITIONS WILL BE MONITORED ACROSS WRN NEB THIS
AFTERNOON DEPENDING ON THE PROGRESS OF A CLEARING LINE FCST TO
DEVELOP ACROSS THE PANHANDLE THIS MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
556 AM CDT TUE OCT 23 2012
.AVIATION...12Z KGRI TAF...STRATUS CONTINUES TO COVER A GOOD
PORTION OF THE CENTRAL PLAINS THIS MORNING WITH LIFR/IFR CIGS
MIXED THROUGHOUT AREAS OF FG/BR/-DZ. EXPECT THE LIFR/IFR
CONDITIONS WILL PERSIST THROUGH AROUND 23/16Z...WHEN CIGS AND
VISIBILITIES ARE EXPECTED TO BEGIN TO IMPROVE MORE SUBSTANTIALLY
AS WINDS BEGIN TO INCREASE OUT OF THE SOUTH AND SOME MIXING ALLOWS
FOR CIGS/VSBYS TO BEGIN TO LIFT/IMPROVE. THIS IMPROVING TREND IS
EXPECTED TO CONTINUE THROUGH EARLY AFTERNOON...WITH A RETURN TO
VFR CIGS/VSBYS EXPECTED BY 23/19Z...AS INDICATED BY LATEST SHORT
TERM GUIDANCE.
&&
.PREV DISCUSSION... /ISSUED 516 AM CDT TUE OCT 23 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. ANOTHER NIGHT...AND ANOTHER
SET OF SEVERAL TRICKY FORECAST ELEMENTS DURING THE NEXT 72
HOURS...NAMELY HIGH TEMPS AND PRECIP/FOG TRENDS...AND WHETHER ANY
STORMS WED NIGHT MIGHT GO SEVERE.
09Z OBJECTIVE SURFACE ANALYSIS CONFIRMS THAT THE ENTIRE CWA LIES
NORTH OF A QUASI-STATIONARY BOUNDARY SNAKING EAST-NORTHEAST ACROSS
SOUTHERN/EASTERN KANSAS AND EXTENDING FROM A WEAK 1003MB LOW IN
SOUTHEAST CO. BREEZES ACROSS THE CWA RANGE FROM LIGHT/VARIABLE TO
LIGHT EASTERLY...WITH LITTLE IF ANY TEMP/DEWPOINT DEPRESSION WITH
VALUES RANGING GENERALLY 47-53 ALL AREAS. AS EXPECTED 24 HOURS
AGO...VARYING DEGREES OF FOG HAVE SETTLED IN OVERNIGHT...WITH THE
ENTIRE CWA SEEING NO BETTER THAN 2-3 MILE VISIBILITY...AND THE MOST
CONCENTRATED ZONE OF DENSE FOG 1/4 MILE OR LOWER VSBY FOCUSED FROM
I-80 SOUTHWARD INTO KANSAS PER AUTOMATED OBS AND WEBCAMS. LIGHT
DRIZZLE HAS SEEMINGLY BEEN OFF AND ON OVERNIGHT...BUT IS LIKELY
STILL PRESENT IN MUCH OF THE CWA. ALOFT...WATER VAPOR SATELLITE
IMAGERY AND LATEST MODEL DATA CONFIRM BROAD WEST- SOUTHWEST FLOW
OVER THE CENTRAL PLAINS...WHICH IS POSITIONED DOWNSTREAM FROM A
LARGE SCALE TROUGH ANCHORED ACROSS THE PACIFIC NORTHWEST WITH A
CLOSED 500MB LOW OFF THE WASHINGTON STATE COAST. CLOSER TO
HOME...A SMALL SCALE SHORTWAVE TROUGH IS CURRENTLY DEPARTING
EASTWARD ACROSS MO...PROMOTING CONSIDERABLE ELEVATED THUNDERSTORM
ACTIVITY IN THAT AREA.
STARTING OFF EARLY THIS MORNING...THE MOST IMMEDIATE ISSUE IS THE
ONGOING CWA-WIDE DENSE FOG ADVISORY VALID THROUGH 15Z...AND WILL
LET IT RIDE AS-IS FOR NOW. TECHNICALLY SPEAKING...AUTOMATED OBS
SUGGEST THAT SO FAR THE MAJORITY OF ANY LOCALLY DENSE FOG HAS BEEN
CONFINED TO AREAS SOUTH OF THE I-80 CORRIDOR...BUT VARIOUS SHORT
TERM VISIBILITY GUIDANCE FROM THE HRRR/SREF SUGGEST THAT A
NORTHWARD EXPANSION OF DENSE FOG IS QUITE POSSIBLE YET THIS
MORNING...AND AM NOT ABOUT TO CANCEL ANY OF THIS ADVISORY UNTIL
TRENDS CAN BE MONITORED FOR AT LEAST A FEW MORE HOURS. IN
FACT...AM STARTING TO EVEN WONDER IF THE 15Z EXPIRATION TIME WILL
BE LONG ENOUGH...WITH BOTH THE HRRR AND HOURLY GFS LAMP GUIDANCE
SUGGESTING THAT SOME AREAS COULD REMAIN RATHER SOCKED IN UNTIL AT
LEAST 16Z-17Z. DAY SHIFT WILL HAVE TO KEEP AN EYE ON THE POSSIBLE
NEED FOR AN EXTENSION. AS FOR THE OFF AND ON LIGHT DRIZZLE SUCH AS
OBSERVED HERE AT THE WFO TONIGHT...HAVE IT MENTIONED CWA-WIDE
THROUGH 12Z...BUT HAVE THEN ATTEMPTED TO CONFINE IT TO ONLY A
HANDFUL OF COUNTIES EAST OF HWY 281 POST-SUNRISE...WHERE NAM
SOUNDINGS INDICATED THAT THE SATURATED LAYER WOULD REMAIN
DEEPER...GENERALLY NEAR/IN EXCESS OF 2500 FT. THAT BEING
SAID...CANNOT COMPLETELY RULE OUT POST-SUNRISE LIGHT DRIZZLE EVEN
IN THE TRI-CITIES AREA WESTWARD GIVEN SUCH A MOIST LOW LEVEL
PROFILE. AS FOR SKY COVER...CONFIDENCE IS CONSIDERABLY HIGHER
TODAY THAT MUCH OF THE CWA WILL SEE AT LEAST A FEW HOURS OF PARTLY
TO MOSTLY SUNNY SKIES AT SOME POINT...BUT EXACTLY WHEN IS STILL
IN QUESTION. HAVE GENERALLY FOLLOWED THE 00Z/06Z NAM SOLUTION OF
KEEPING NEARLY ALL AREAS SOCKED IN WITH STRATUS AND AT LEAST LIGHT
FOG THROUGH THE MORNING HOURS...BUT THEN ERODING FROM WEST-EAST
THROUGH THE AFTERNOON WEARS ON AS EVIDENCED BY THE 900MB RELATIVE
HUMIDITY FIELD. THIS MEANS THAT FAR EASTERN COUNTIES ALONG THE HWY
81 WOULD BE LAST TO SEE ANY CLEARING. AFTER BUSTING HIGH TEMPS BY
10+ DEGREES YESTERDAY DUE TO WIDESPREAD LOW STRATUS...AM IN NO
HURRY TO GO WITH THE WARM END OF AVAILABLE GUIDANCE/MODEL
SOLUTIONS TODAY ESPECIALLY IN EASTERN ZONES. AFTER TRYING VARIOUS
SOLUTIONS ON FOR SIZE...ENDED UP GOING WITH THE 00Z NAM ALMOST
EXACTLY...AS ITS TEMP FIELD SEEMED TO BEST-CAPTURE THE GRADUAL
WEST-EAST CLEARING. THIS RESULTS IN A DECENT RANGE FROM NEAR 80
FAR WEST ...LOW-MID 70S CENTRAL AND UPPER 60S EAST. PLEASE NOTE
THESE VALUES ARE AT LEAST A FEW DEGREES COOLER THAN PREVIOUS
FORECAST ALL AREAS...AND AS MUCH AS 5-8 DEGREES COOLER IN THE
EAST. LIKE YESTERDAY...COULD EASILY FORESEE HIGHS BEING OFF BY 5+
DEGREES DEPENDING ON STRATUS/FOG TRENDS.
TONIGHT...KEPT OUT ALL MENTION OF PRECIP CWA-WIDE...AND AM NOT
EXPECTING A DENSE FOG REPEAT SUCH AS THE ONGOING ONE...BUT DID
INSERT A PATCHY FOG MENTION INTO SEVERAL COUNTIES NORTH OF I-80
AFTER MIDNIGHT IN CLOSEST PROXIMITY TO THE HIGHEST BOUNDARY LAYER
RELATIVE HUMIDITY POOLING IN THE VICINITY OF THE LEADING EDGES OF
THE INVADING COLD FRONT. CLOUD TRENDS TONIGHT ARE CERTAINLY A
CHALLENGE...WITH THE POTENTIAL FOR QUITE AN INCREASE IN STRATUS
TOWARD SUNRISE NEAR THIS BOUNDARY...FOLLOWING WHAT SHOULD BE A
FAIRLY CLEAR EVENING FOR MOST AREAS. ALOFT...THE BIG PICTURE
INVOLVES A LEAD SHORTWAVE TRACKING ACROSS FAR SOUTH CENTRAL
CANADA...WHICH HELPS DRIVE THE SURFACE FRONT INTO THE NORTHERN
CWA...WHILE A TROUGH AXIS SETS UP FROM SOUTHWEST-NORTHEAST ACROSS
KS. KEPT LOWS SIMILAR TO PREVIOUS FORECAST AND A GUIDANCE
BLEND...RANGING FROM LOW-MID 40S NORTHWEST TO UPPER 50S/NEAR 60
SOUTHEAST WHERE DEWPOINTS WILL BE ON THE INCREASE.
WEDNESDAY...OTHER THAN THE LINGERING PATCHY FOG MENTION NORTH IN
THE MORNING...HAVE KEPT OUT ANY OTHER WEATHER MENTION THROUGH
SUNSET...AS THE GENERAL MODEL CONSENSUS IS TO KEEP ANY LIGHT
DAYTIME DRIZZLY PRECIP NORTHEAST OF THE CWA...AND ANY LATE-DAY
CONVECTION ALONG/NEAR THE INVADING COLD FRONT JUST SOUTHEAST OF
THE CWA. THAT BEING SAID...SKY COVER AND TEMP TRENDS ARE AGAIN
QUITE A CHALLENGE...AS QUITE A BIT OF STRATUS SHOULD DOMINATE MUCH
OF THE NORTHWEST CWA WITH MORE SUNSHINE SOUTHEAST.
FORTUNATELY...THE LATEST MODEL RUNS ARE IN REASONABLY GOOD
AGREEMENT REGARDING WHAT WILL CERTAINLY BE A SHARP TEMP
GRADIENT...AND ONLY MADE MINOR ADJUSTMENTS TO PREVIOUS
FORECAST...AIMING FOR A RANGE FROM UPPER 50S FAR NORTH...MID 60S
TO LOW 70S TRI CITIES AREA...AND LOW 80S FAR SOUTHEAST IN THE
HEBRON-BELOIT CORRIDOR. AGAIN THOUGH...5+ DEGREE DEVIATIONS FROM
CURRENT FORECAST ARE VERY POSSIBLE IF NOT LIKELY. PONDERED GOING
WITH A NON-DIURNAL TEMP TREND BEHIND THE FRONT...BUT MODELS ARE
NOT REALLY SHOWING MUCH OF AN AFTERNOON DROP SO STUCK WITH
TRADITIONAL MID-LATE AFTERNOON HIGHS ALL AREAS FOR NOW. THIS COLD
FRONT WILL NOT EXACTLY BLAST THROUGH THE AREA...AND BY SUNSET WILL
JUST BE REACHING FAR SOUTHEAST ZONES...WHILE MOST OF THE CWA WILL
ALREADY BE IN SUSTAINED NORTH WINDS 15-20 MPH.
WEDNESDAY NIGHT IS CLEARLY STILL THE MAIN 12-HOUR WINDOW FOR
POTENTIALLY DECENT RAIN AMOUNTS...AND ACTUALLY RAISED POPS INTO
THE 60-70 PERCENT RANGE ACROSS MUCH OF THE EASTERN CWA...WHILE
LEAVING SOUTHWEST AREAS IN THE 40-50 PERCENT RANGE. IN
SHORT...LARGE SCALE FORCING/MID LEVEL FRONTOGENESIS RAMPS UP AS A
POTENT OPEN WAVE OVER THE CENTRAL ROCKIES MOVES INTO THE CENTRAL
PLAINS...FEATURING A 110+KT 300MB JET STREAK. LEFT THE POP/WEATHER
GRIDS AS ONE 12-HOUR BLOCK FOR NOW...BUT GENERAL THINKING IS THAT
MOST WIDESPREAD COVERAGE OF SHOWERS/STORMS WILL HOLD OFF UNTIL
NEAR/AFTER MIDNIGHT...UNLESS SOME EVENING ACTIVITY FLARES UP IN
THE FAR SOUTH/SOUTHEAST NEAR THE MAIN SURFACE FRONT. LATEST NAM
CONTINUES TO SHOW A HEALTHY CORRIDOR OF MUCAPE 1500+ J/KG IN THE
850-700MB LAYER MAINLY ACROSS THE SOUTHEAST 1/2 OF THE
CWA...DROPPING OFF SHORTLY TO THE NORTHWEST. HOWEVER...WILL KEEP
ISOLATED THUNDER EVEN IN THIS NORTHWEST AREAS. WITH VERY STRONG
DEEP-LAYER SHEAR OF 60+ KNOTS MOVING IN...HAVE INCREASING CONCERNS
THAT AT LEAST MARGINALLY SEVERE HAIL COULD OCCUR IN SOUTHEAST
COUNTIES...AND DESPITE SPC KEEPING THE OFFICIAL DAY2 SLIGHT RISK
OUTLOOK JUST EAST OF THE CWA...AT LEAST FOR NOW...WILL GO AHEAD
AND ADD THIS MENTION TO THE HAZARDOUS WEATHER OUTLOOK AS THESE
STRONG DYNAMICS ARE HARD TO IGNORE. DEPENDING ON HOW WIDESPREAD
STORMS ARE...COULD FORESEE SOME FORTUNATE AREAS RECEIVING IN
EXCESS OF ONE-HALF INCH OF RAIN BUT THIS WILL PROBABLY BE THE
EXCEPTION. ALTHOUGH SOME SNOW OR RAIN/SNOW MIX COULD TRY
DEVELOPING IN WESTERN NEBRASKA IN THE COLDER AIR WELL BEHIND THE
FRONT...LATEST CONSENSUS IS THAT WINTRY PRECIP WED NIGHT SHOULD
FOCUS AT LEAST 50 MILES WEST OF THE CWA...AND THUS WILL KEEP ANY
SNOW MENTION OUT FOR NOW.
THURSDAY...SPLIT THE DAY INTO 6-HOUR BLOCKS...WITH ALL PRECIP GONE
BY THE AFTERNOON HOURS...AND POTENTIALLY EVEN GONE BY MID-MORNING
IN MOST AREAS PER SOME OF THE LATEST TRENDS INCLUDING THE 00Z
ECMWF...WHICH QUICKLY SHUTS OFF THE MID LEVEL LIFT/SATURATION FROM
NORTHWEST-SOUTHEAST. LATER ADJUSTMENTS WILL BE NEEDED...BUT FOR NOW
KEPT 20-40 POPS ACROSS MOST OF THE CWA IN THE MORNING FOR GENERAL
LIGHT RAIN...WITH NO THUNDER MENTION AND STILL NO SNOW
MENTION...ALTHOUGH SUPPOSE A FEW FLURRIES COULD SNEAK INTO FAR
NORTHWEST ZONES JUST BEFORE PRECIP SHUTS OFF FOR GOOD GIVEN
SURFACE TEMPS FORECAST TO DROP INTO THE MID 30S EARLY THURSDAY
MORNING. OTHERWISE...EXPECT INCREASING SUNSHINE AS THE DAY WEARS
ON...ALTHOUGH IT WILL REMAIN QUITE BREEZY WITH SUSTAINED NORTH
WINDS AROUND 20 MPH WITH GUSTS TO AROUND 30 MPH. FOR HIGH
TEMPS...RAW NAM VALUES ARE WELL INTO THE MID 50S ALL AREAS...BUT
WAS NOT WILLING TO GO QUITE THIS WARM YET...AND THUS ONLY MADE
MINOR ADJUSTMENTS TO PREVIOUS FORECAST WITH MOST NEB ZONES TOPPING
OUT UPPER 40S AND KS LOWER 50S.
THURS NIGHT...THIS LOOKS TO BE THE MOST UNEVENTFUL PERIOD OF THE
NEXT 72 HOURS...AS AN EXPANSIVE SURFACE RIDGE AXIS SETTLES INTO
THE REGION FROM THE NORTH...AND ANY LIGHT SNOW ACCUMULATIONS
ASSOCIATED WITH TRAILING MID LEVEL SHORTWAVE ENERGY AND LOW LEVEL
UPSLOPE FLOW SHOULD REMAIN NO CLOSER THAN THE NEB/CO/KS BORDER
AREA. DESPITE A POTENTIAL INCREASE IN MID LEVEL CLOUDS...OPTED TO
LOWER LOW TEMPS 2-3 DEGREES FROM PREVIOUS FCST AND POSSIBLY NOT
ENOUGH...BUT AT LEAST GETTING ALL AREAS INTO THE SUB-FREEZING
26-32 RANGE.
LONG TERM...STARTING 12Z FRIDAY...THE LONGWAVE TROUGH ACROSS THE
WEST COAST THIS MORNING WILL BE CENTERED OVER THE PLAINS ON
FRIDAY...WITH SEVERAL EMBEDDED WEAK DISTURBANCES EXPECTED TO HAVE
LITTLE IMPACT IN THE WAY OF CHANCES FOR PRECIP ACROSS THE LOCAL
AREA. SOME DISCREPANCIES EVIDENT WITH THE HANDLING OF THIS TROUGH
AS IT PUSHES EAST LATE IN THE WEEKEND...WITH THE EC QUICKLY BUILDING
A RIDGE OVER THE INTERMOUNTAIN WEST RESULTING IN RISING HEIGHTS
ACROSS THE PLAINS...IN RESPONSE TO THE LONGWAVE TROUGH INTERACTS
WITH A TROPICAL DISTURBANCE OFF THE EASTERN SEABOARD...AND THE
LATEST GFS DEPICTING A MORE ZONAL WEST TO NORTHWEST FLOW ACROSS THE
REGION BY EARLY NEXT WEEK...AS THE AFOREMENTIONED TROPICAL
DISTURBANCE INSTEAD TRACKS OUT INTO THE OPEN ATLANTIC. EITHER
WAY...THIS APPEARS TO BE A DRY PATTERN FOR THE LOCAL AREA AS THERE
ARE NO SIGNIFICANT FEATURES FORECAST TO IMPACT THE AREA IN THE
DIVERGENT UPPER LEVEL FLOW PATTERNS DEPICTED AMONGST THE LONG TERM
MODELS. THEREFORE...EXPECT DRY CONDITIONS...WITH CONTINUED
UNSEASONABLY COOL TEMPERATURES...TO AT LEAST START THE EXTENDED
PERIODS...WITH TEMPERATURES POSSIBLY WARMING CLOSER TO
CLIMATOLOGY...WHILE REMAINING DRY...EARLY NEXT WEEK IF THE EC
SOLUTION ENDS UP BEING CORRECT. HOWEVER...DUE TO THE UNCERTAINTY OF
THE SYNOPTIC SCALE PATTERN EARLY NEXT WEEK...STUCK WITH ALLBLEND
MODEL SOLUTION THIS MORNING...WITH NO NOTABLE TWEAKS TO SPEAK OF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
516 AM CDT TUE OCT 23 2012
.SHORT TERM...THROUGH THURSDAY NIGHT. ANOTHER NIGHT...AND ANOTHER
SET OF SEVERAL TRICKY FORECAST ELEMENTS DURING THE NEXT 72
HOURS...NAMELY HIGH TEMPS AND PRECIP/FOG TRENDS...AND WHETHER ANY
STORMS WED NIGHT MIGHT GO SEVERE.
09Z OBJECTIVE SURFACE ANALYSIS CONFIRMS THAT THE ENTIRE CWA LIES
NORTH OF A QUASI-STATIONARY BOUNDARY SNAKING EAST-NORTHEAST ACROSS
SOUTHERN/EASTERN KANSAS AND EXTENDING FROM A WEAK 1003MB LOW IN
SOUTHEAST CO. BREEZES ACROSS THE CWA RANGE FROM LIGHT/VARIABLE TO
LIGHT EASTERLY...WITH LITTLE IF ANY TEMP/DEWPOINT DEPRESSION WITH
VALUES RANGING GENERALLY 47-53 ALL AREAS. AS EXPECTED 24 HOURS
AGO...VARYING DEGREES OF FOG HAVE SETTLED IN OVERNIGHT...WITH THE
ENTIRE CWA SEEING NO BETTER THAN 2-3 MILE VISIBILITY...AND THE MOST
CONCENTRATED ZONE OF DENSE FOG 1/4 MILE OR LOWER VSBY FOCUSED FROM
I-80 SOUTHWARD INTO KANSAS PER AUTOMATED OBS AND WEBCAMS. LIGHT
DRIZZLE HAS SEEMINGLY BEEN OFF AND ON OVERNIGHT...BUT IS LIKELY
STILL PRESENT IN MUCH OF THE CWA. ALOFT...WATER VAPOR SATELLITE
IMAGERY AND LATEST MODEL DATA CONFIRM BROAD WEST- SOUTHWEST FLOW
OVER THE CENTRAL PLAINS...WHICH IS POSITIONED DOWNSTREAM FROM A
LARGE SCALE TROUGH ANCHORED ACROSS THE PACIFIC NORTHWEST WITH A
CLOSED 500MB LOW OFF THE WASHINGTON STATE COAST. CLOSER TO
HOME...A SMALL SCALE SHORTWAVE TROUGH IS CURRENTLY DEPARTING
EASTWARD ACROSS MO...PROMOTING CONSIDERABLE ELEVATED THUNDERSTORM
ACTIVITY IN THAT AREA.
STARTING OFF EARLY THIS MORNING...THE MOST IMMEDIATE ISSUE IS THE
ONGOING CWA-WIDE DENSE FOG ADVISORY VALID THROUGH 15Z...AND WILL
LET IT RIDE AS-IS FOR NOW. TECHNICALLY SPEAKING...AUTOMATED OBS
SUGGEST THAT SO FAR THE MAJORITY OF ANY LOCALLY DENSE FOG HAS BEEN
CONFINED TO AREAS SOUTH OF THE I-80 CORRIDOR...BUT VARIOUS SHORT
TERM VISIBILITY GUIDANCE FROM THE HRRR/SREF SUGGEST THAT A
NORTHWARD EXPANSION OF DENSE FOG IS QUITE POSSIBLE YET THIS
MORNING...AND AM NOT ABOUT TO CANCEL ANY OF THIS ADVISORY UNTIL
TRENDS CAN BE MONITORED FOR AT LEAST A FEW MORE HOURS. IN
FACT...AM STARTING TO EVEN WONDER IF THE 15Z EXPIRATION TIME WILL
BE LONG ENOUGH...WITH BOTH THE HRRR AND HOURLY GFS LAMP GUIDANCE
SUGGESTING THAT SOME AREAS COULD REMAIN RATHER SOCKED IN UNTIL AT
LEAST 16Z-17Z. DAY SHIFT WILL HAVE TO KEEP AN EYE ON THE POSSIBLE
NEED FOR AN EXTENSION. AS FOR THE OFF AND ON LIGHT DRIZZLE SUCH AS
OBSERVED HERE AT THE WFO TONIGHT...HAVE IT MENTIONED CWA-WIDE
THROUGH 12Z...BUT HAVE THEN ATTEMPTED TO CONFINE IT TO ONLY A
HANDFUL OF COUNTIES EAST OF HWY 281 POST-SUNRISE...WHERE NAM
SOUNDINGS INDICATED THAT THE SATURATED LAYER WOULD REMAIN
DEEPER...GENERALLY NEAR/IN EXCESS OF 2500 FT. THAT BEING
SAID...CANNOT COMPLETELY RULE OUT POST-SUNRISE LIGHT DRIZZLE EVEN
IN THE TRI-CITIES AREA WESTWARD GIVEN SUCH A MOIST LOW LEVEL
PROFILE. AS FOR SKY COVER...CONFIDENCE IS CONSIDERABLY HIGHER
TODAY THAT MUCH OF THE CWA WILL SEE AT LEAST A FEW HOURS OF PARTLY
TO MOSTLY SUNNY SKIES AT SOME POINT...BUT EXACTLY WHEN IS STILL
IN QUESTION. HAVE GENERALLY FOLLOWED THE 00Z/06Z NAM SOLUTION OF
KEEPING NEARLY ALL AREAS SOCKED IN WITH STRATUS AND AT LEAST LIGHT
FOG THROUGH THE MORNING HOURS...BUT THEN ERODING FROM WEST-EAST
THROUGH THE AFTERNOON WEARS ON AS EVIDENCED BY THE 900MB RELATIVE
HUMIDITY FIELD. THIS MEANS THAT FAR EASTERN COUNTIES ALONG THE HWY
81 WOULD BE LAST TO SEE ANY CLEARING. AFTER BUSTING HIGH TEMPS BY
10+ DEGREES YESTERDAY DUE TO WIDESPREAD LOW STRATUS...AM IN NO
HURRY TO GO WITH THE WARM END OF AVAILABLE GUIDANCE/MODEL
SOLUTIONS TODAY ESPECIALLY IN EASTERN ZONES. AFTER TRYING VARIOUS
SOLUTIONS ON FOR SIZE...ENDED UP GOING WITH THE 00Z NAM ALMOST
EXACTLY...AS ITS TEMP FIELD SEEMED TO BEST-CAPTURE THE GRADUAL
WEST-EAST CLEARING. THIS RESULTS IN A DECENT RANGE FROM NEAR 80
FAR WEST ...LOW-MID 70S CENTRAL AND UPPER 60S EAST. PLEASE NOTE
THESE VALUES ARE AT LEAST A FEW DEGREES COOLER THAN PREVIOUS
FORECAST ALL AREAS...AND AS MUCH AS 5-8 DEGREES COOLER IN THE
EAST. LIKE YESTERDAY...COULD EASILY FORESEE HIGHS BEING OFF BY 5+
DEGREES DEPENDING ON STRATUS/FOG TRENDS.
TONIGHT...KEPT OUT ALL MENTION OF PRECIP CWA-WIDE...AND AM NOT
EXPECTING A DENSE FOG REPEAT SUCH AS THE ONGOING ONE...BUT DID
INSERT A PATCHY FOG MENTION INTO SEVERAL COUNTIES NORTH OF I-80
AFTER MIDNIGHT IN CLOSEST PROXIMITY TO THE HIGHEST BOUNDARY LAYER
RELATIVE HUMIDITY POOLING IN THE VICINITY OF THE LEADING EDGES OF
THE INVADING COLD FRONT. CLOUD TRENDS TONIGHT ARE CERTAINLY A
CHALLENGE...WITH THE POTENTIAL FOR QUITE AN INCREASE IN STRATUS
TOWARD SUNRISE NEAR THIS BOUNDARY...FOLLOWING WHAT SHOULD BE A
FAIRLY CLEAR EVENING FOR MOST AREAS. ALOFT...THE BIG PICTURE
INVOLVES A LEAD SHORTWAVE TRACKING ACROSS FAR SOUTH CENTRAL
CANADA...WHICH HELPS DRIVE THE SURFACE FRONT INTO THE NORTHERN
CWA...WHILE A TROUGH AXIS SETS UP FROM SOUTHWEST-NORTHEAST ACROSS
KS. KEPT LOWS SIMILAR TO PREVIOUS FORECAST AND A GUIDANCE
BLEND...RANGING FROM LOW-MID 40S NORTHWEST TO UPPER 50S/NEAR 60
SOUTHEAST WHERE DEWPOINTS WILL BE ON THE INCREASE.
WEDNESDAY...OTHER THAN THE LINGERING PATCHY FOG MENTION NORTH IN
THE MORNING...HAVE KEPT OUT ANY OTHER WEATHER MENTION THROUGH
SUNSET...AS THE GENERAL MODEL CONSENSUS IS TO KEEP ANY LIGHT
DAYTIME DRIZZLY PRECIP NORTHEAST OF THE CWA...AND ANY LATE-DAY
CONVECTION ALONG/NEAR THE INVADING COLD FRONT JUST SOUTHEAST OF
THE CWA. THAT BEING SAID...SKY COVER AND TEMP TRENDS ARE AGAIN
QUITE A CHALLENGE...AS QUITE A BIT OF STRATUS SHOULD DOMINATE MUCH
OF THE NORTHWEST CWA WITH MORE SUNSHINE SOUTHEAST.
FORTUNATELY...THE LATEST MODEL RUNS ARE IN REASONABLY GOOD
AGREEMENT REGARDING WHAT WILL CERTAINLY BE A SHARP TEMP
GRADIENT...AND ONLY MADE MINOR ADJUSTMENTS TO PREVIOUS
FORECAST...AIMING FOR A RANGE FROM UPPER 50S FAR NORTH...MID 60S
TO LOW 70S TRI CITIES AREA...AND LOW 80S FAR SOUTHEAST IN THE
HEBRON-BELOIT CORRIDOR. AGAIN THOUGH...5+ DEGREE DEVIATIONS FROM
CURRENT FORECAST ARE VERY POSSIBLE IF NOT LIKELY. PONDERED GOING
WITH A NON-DIURNAL TEMP TREND BEHIND THE FRONT...BUT MODELS ARE
NOT REALLY SHOWING MUCH OF AN AFTERNOON DROP SO STUCK WITH
TRADITIONAL MID-LATE AFTERNOON HIGHS ALL AREAS FOR NOW. THIS COLD
FRONT WILL NOT EXACTLY BLAST THROUGH THE AREA...AND BY SUNSET WILL
JUST BE REACHING FAR SOUTHEAST ZONES...WHILE MOST OF THE CWA WILL
ALREADY BE IN SUSTAINED NORTH WINDS 15-20 MPH.
WEDNESDAY NIGHT IS CLEARLY STILL THE MAIN 12-HOUR WINDOW FOR
POTENTIALLY DECENT RAIN AMOUNTS...AND ACTUALLY RAISED POPS INTO
THE 60-70 PERCENT RANGE ACROSS MUCH OF THE EASTERN CWA...WHILE
LEAVING SOUTHWEST AREAS IN THE 40-50 PERCENT RANGE. IN
SHORT...LARGE SCALE FORCING/MID LEVEL FRONTOGENESIS RAMPS UP AS A
POTENT OPEN WAVE OVER THE CENTRAL ROCKIES MOVES INTO THE CENTRAL
PLAINS...FEATURING A 110+KT 300MB JET STREAK. LEFT THE POP/WEATHER
GRIDS AS ONE 12-HOUR BLOCK FOR NOW...BUT GENERAL THINKING IS THAT
MOST WIDESPREAD COVERAGE OF SHOWERS/STORMS WILL HOLD OFF UNTIL
NEAR/AFTER MIDNIGHT...UNLESS SOME EVENING ACTIVITY FLARES UP IN
THE FAR SOUTH/SOUTHEAST NEAR THE MAIN SURFACE FRONT. LATEST NAM
CONTINUES TO SHOW A HEALTHY CORRIDOR OF MUCAPE 1500+ J/KG IN THE
850-700MB LAYER MAINLY ACROSS THE SOUTHEAST 1/2 OF THE
CWA...DROPPING OFF SHORTLY TO THE NORTHWEST. HOWEVER...WILL KEEP
ISOLATED THUNDER EVEN IN THIS NORTHWEST AREAS. WITH VERY STRONG
DEEP-LAYER SHEAR OF 60+ KNOTS MOVING IN...HAVE INCREASING CONCERNS
THAT AT LEAST MARGINALLY SEVERE HAIL COULD OCCUR IN SOUTHEAST
COUNTIES...AND DESPITE SPC KEEPING THE OFFICIAL DAY2 SLIGHT RISK
OUTLOOK JUST EAST OF THE CWA...AT LEAST FOR NOW...WILL GO AHEAD
AND ADD THIS MENTION TO THE HAZARDOUS WEATHER OUTLOOK AS THESE
STRONG DYNAMICS ARE HARD TO IGNORE. DEPENDING ON HOW WIDESPREAD
STORMS ARE...COULD FORESEE SOME FORTUNATE AREAS RECEIVING IN
EXCESS OF ONE-HALF INCH OF RAIN BUT THIS WILL PROBABLY BE THE
EXCEPTION. ALTHOUGH SOME SNOW OR RAIN/SNOW MIX COULD TRY
DEVELOPING IN WESTERN NEBRASKA IN THE COLDER AIR WELL BEHIND THE
FRONT...LATEST CONSENSUS IS THAT WINTRY PRECIP WED NIGHT SHOULD
FOCUS AT LEAST 50 MILES WEST OF THE CWA...AND THUS WILL KEEP ANY
SNOW MENTION OUT FOR NOW.
THURSDAY...SPLIT THE DAY INTO 6-HOUR BLOCKS...WITH ALL PRECIP GONE
BY THE AFTERNOON HOURS...AND POTENTIALLY EVEN GONE BY MID-MORNING
IN MOST AREAS PER SOME OF THE LATEST TRENDS INCLUDING THE 00Z
ECMWF...WHICH QUICKLY SHUTS OFF THE MID LEVEL LIFT/SATURATION FROM
NORTHWEST-SOUTHEAST. LATER ADJUSTMENTS WILL BE NEEDED...BUT FOR NOW
KEPT 20-40 POPS ACROSS MOST OF THE CWA IN THE MORNING FOR GENERAL
LIGHT RAIN...WITH NO THUNDER MENTION AND STILL NO SNOW
MENTION...ALTHOUGH SUPPOSE A FEW FLURRIES COULD SNEAK INTO FAR
NORTHWEST ZONES JUST BEFORE PRECIP SHUTS OFF FOR GOOD GIVEN
SURFACE TEMPS FORECAST TO DROP INTO THE MID 30S EARLY THURSDAY
MORNING. OTHERWISE...EXPECT INCREASING SUNSHINE AS THE DAY WEARS
ON...ALTHOUGH IT WILL REMAIN QUITE BREEZY WITH SUSTAINED NORTH
WINDS AROUND 20 MPH WITH GUSTS TO AROUND 30 MPH. FOR HIGH
TEMPS...RAW NAM VALUES ARE WELL INTO THE MID 50S ALL AREAS...BUT
WAS NOT WILLING TO GO QUITE THIS WARM YET...AND THUS ONLY MADE
MINOR ADJUSTMENTS TO PREVIOUS FORECAST WITH MOST NEB ZONES TOPPING
OUT UPPER 40S AND KS LOWER 50S.
THURS NIGHT...THIS LOOKS TO BE THE MOST UNEVENTFUL PERIOD OF THE
NEXT 72 HOURS...AS AN EXPANSIVE SURFACE RIDGE AXIS SETTLES INTO
THE REGION FROM THE NORTH...AND ANY LIGHT SNOW ACCUMULATIONS
ASSOCIATED WITH TRAILING MID LEVEL SHORTWAVE ENERGY AND LOW LEVEL
UPSLOPE FLOW SHOULD REMAIN NO CLOSER THAN THE NEB/CO/KS BORDER
AREA. DESPITE A POTENTIAL INCREASE IN MID LEVEL CLOUDS...OPTED TO
LOWER LOW TEMPS 2-3 DEGREES FROM PREVIOUS FCST AND POSSIBLY NOT
ENOUGH...BUT AT LEAST GETTING ALL AREAS INTO THE SUB-FREEZING
26-32 RANGE.
.LONG TERM...STARTING 12Z FRIDAY...THE LONGWAVE TROUGH ACROSS THE
WEST COAST THIS MORNING WILL BE CENTERED OVER THE PLAINS ON
FRIDAY...WITH SEVERAL EMBEDDED WEAK DISTURBANCES EXPECTED TO HAVE
LITTLE IMPACT IN THE WAY OF CHANCES FOR PRECIP ACROSS THE LOCAL
AREA. SOME DISCREPANCIES EVIDENT WITH THE HANDLING OF THIS TROUGH
AS IT PUSHES EAST LATE IN THE WEEKEND...WITH THE EC QUICKLY BUILDING
A RIDGE OVER THE INTERMOUNTAIN WEST RESULTING IN RISING HEIGHTS
ACROSS THE PLAINS...IN RESPONSE TO THE LONGWAVE TROUGH INTERACTS
WITH A TROPICAL DISTURBANCE OFF THE EASTERN SEABOARD...AND THE
LATEST GFS DEPICTING A MORE ZONAL WEST TO NORTHWEST FLOW ACROSS THE
REGION BY EARLY NEXT WEEK...AS THE AFOREMENTIONED TROPICAL
DISTURBANCE INSTEAD TRACKS OUT INTO THE OPEN ATLANTIC. EITHER
WAY...THIS APPEARS TO BE A DRY PATTERN FOR THE LOCAL AREA AS THERE
ARE NO SIGNIFICANT FEATURES FORECAST TO IMPACT THE AREA IN THE
DIVERGENT UPPER LEVEL FLOW PATTERNS DEPICTED AMONGST THE LONG TERM
MODELS. THEREFORE...EXPECT DRY CONDITIONS...WITH CONTINUED
UNSEASONABLY COOL TEMPERATURES...TO AT LEAST START THE EXTENDED
PERIODS...WITH TEMPERATURES POSSIBLY WARMING CLOSER TO
CLIMATOLOGY...WHILE REMAINING DRY...EARLY NEXT WEEK IF THE EC
SOLUTION ENDS UP BEING CORRECT. HOWEVER...DUE TO THE UNCERTAINTY OF
THE SYNOPTIC SCALE PATTERN EARLY NEXT WEEK...STUCK WITH ALLBLEND
MODEL SOLUTION THIS MORNING...WITH NO NOTABLE TWEAKS TO SPEAK OF.
&&
.PREV DISCUSSION... /ISSUED 1243 AM CDT TUE OCT 23 2012/
AVIATION...06Z TAF. STRATUS CONTINUES TO ENCOMPASS A GOOD
PORTION OF THE CENTRAL PLAINS AND CIGS ARE EXPECTED TO REMAIN LIFR
THROUGH THE EARLY MORNING HOURS TUESDAY. IN PRESENCE OF LLVL
MOISTURE AND MIXING ABOVE THE MOISTURE/CLOUD DECK...LOOK FOR
INTERMITTENT DRIZZLE FOR AT LEAST THE FIRST PART OF THE NIGHT WITH
VSBYS IN THE LIFR CATEGORY IN AREAS OF FG/BR. THE LIFR/IFR
CONDITIONS WILL PERSIST INTO THE FIRST HALF OF THE DAY
TUESDAY...WITH IMPROVEMENT BY MIDDAY...AS CLOUDS BEGIN TO
SCATTER AND DRY AIR BEGINS TO ADVECT IN ACROSS THE REGION. WINDS
OVERNIGHT WILL CONTINUE TO BE LIGHT AND VARIABLE...EVENTUALLY
REACHING ABOUT 10 KTS OUT OF THE SOUTH TUESDAY AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
720 AM EDT TUE OCT 23 2012
.SYNOPSIS...
A FRONT WILL LINGER ACROSS LAKE ERIE THROUGH MID WEEK. NEXT COLD
FRONT WILL PUSH THROUGH LATE FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TWEAKED THE TIMING OF THE SHOWERS THIS MORNING.
ORIGINAL DISCUSSION...
FRONTAL BOUNDARY LINGERING ACROSS THE CENTRAL AND LOWER GREAT LAKES. TWO
SEPARATE WAVES WILL MOVE ALONG THE BOUNDARY TODAY. THE FIRST WAVE
IS WITH THE CONVECTION THIS MORNING. EXPECT A BREAK BY LATE
MORNING THEN A SECOND WAVE LATER THIS AFTERNOON. WHERE WILL THE
SHOWERS SET UP. STILL DOUBTS IN MY MIND...BEST CHANCES WOULD BE
THE LAKESHORE COUNTIES WITH DECREASING CHANCES THE FURTHER SOUTH
YOU GO. EXPECT TEMPS TO REMAIN WELL ABOVE NORMAL WITH TEMPS IN THE
LOWER TO MID 70S. IF GET SOME CLOUD BREAKS EARLY THIS AFTERNOON
BEFORE SECOND WAVE COULD EVEN BE A LITTLE WARMER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
SECOND WAVE WILL EXIT AREA OVERNIGHT WITH A CHANCE OF A FEW
LINGERING SHOWERS INTO WEDNESDAY MORNING. UPPER RIDGE BUILDS
QUICKLY OVER THE AREA WEDNESDAY AND REMAINS IN PLACE TO THE END OF
THE WORK WEEK. AS A RESULT MUCH ABOVE NORMAL TEMPERATURES WILL
CONTINUE THROUGH THURSDAY. BUT ALL GOOD THINGS COME TO AN END. THE ECMWF
IS COMING MORE IN LINE WITH THE GFS TIMING OF THE NEXT SYSTEM.
MODELS PUSH FRONT INTO NW OH FRIDAY AND ACROSS MOST OF AREA FRIDAY
NIGHT.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THIS PERIOD IS BECOMING A LITTLE MORE CLEAR BUT IT STILL HAS SOME
DIFFERENCES. THE FRONT IS EAST OF THE AREA BY SATURDAY MORNING WITH
COLD AIR FLOWING IN FROM MICHIGAN. BY SATURDAY EVENING THE LAKE AND
850 MB TEMPERATURE DIFFERENCE WILL BE NEAR 14C. THE THREAT OF
SHOWERS WILL BE DECREASING FROM WEST TO EAST SATURDAY. HIGH PRESSURE
WILL BE BUILDING IN SLOWLY FROM THE NORTHWEST SATURDAY INTO SUNDAY
AND THAT WILL DECREASE ANY LAKE ENHANCED SHOWERS THAT TRY TO MOVE
INTO NORTHWEST OHIO FROM LAKE MICHIGAN. HOWEVER...LAKE EFFECT
SHOWERS WILL CONTINUE OVER THE EASTERN COUNTIES. ON MONDAY THE 00Z
ECMWF HAS A MORE PRONOUNCED TROF OVER THE EASTERN LAKES. IF THIS
OCCURS IT MAY
KEEP THE THREAT OF PRECIPITATION GOING LONGER AND IT WILL BRING IN A
LITTLE COLDER AIR...SO WE WILL HAVE TO CONTINUE TO MONITOR THE
PRECIPITATION TYPE. AT THIS TIME STILL JUST FORECASTING RAIN. DIDN`T
MAKE MUCH IN THE WAY OF CHANGES TO THE EXTENDED FOR
TEMPERATURES...THEY WILL BE BELOW NORMAL.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
ONE SHORT WAVE WAS MOVING THROUGH THE AREA THIS MORNING AND
CAUSING SOME SHOWERS. ANOTHER SHORT WAVE WILL MOVE THROUGH FOR
THE AFTERNOON. SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THIS ARE
OVER CENTRAL IL AND WEST CENTRAL INDIANA. THEY SEEM TO BE MOVING
FASTER THAN ONE WOULD THINK BASED ON THE LOCATION OF THE SHORT
WAVE. THE HRRR MODEL SEEMS TO HAVE A GOOD HANDLE ON THIS SO WENT
WITH THAT TIMING. CONFIDENCE IS MODERATE ON HOW IT WILL ALL PLAY
OUT WITH THE BEST CHANCES OVER NORTHWEST OHIO AND ALONG THE
LAKESHORE. A STATIONARY FRONT JUST TO THE NORTH OF LAKE ERIE WILL
HELP FOCUS THE PRECIPITATION. CONDITIONS WILL BE MAINLY VFR
EXCEPT BRIEFLY MVFR OR LESS IN THE HEAVIER SHOWERS AND
THUNDERSTORMS. HOWEVER...SOME MVFR CEILINGS COULD DEVELOP IN THE
HIGH MOISTURE NEAR LAKE ERIE. CONFIDENCE IS LOW.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AT TIMES FRIDAY EVENING
THROUGH SATURDAY.
&&
.MARINE...
A BOUNDARY MAY TRY TO DRIFT INTO THE EASTERN PORTION OF LAKE ERIE
LATER TODAY INTO WEDNESDAY. OTHER THAN THAT MAINLY A SOUTH TO
SOUTHWEST FLOW THROUGH FRIDAY. CONDITIONS SHOULD NOT MEET SMALL
CRAFT ADVISORY CRITERIA. THE ONLY THREAT ON THE LAKE THROUGH
WEDNESDAY WILL BE A NEED FOR A SPECIAL MARINE WARNING BECAUSE OF
THUNDERSTORMS AND THAT IS A SMALL CHANCE.
A COLD FRONT WILL MOVE THROUGH FRIDAY INTO FRIDAY NIGHT AND
NORTHERLY WINDS BEHIND IT MAY PROMPT A NEED FOR A SMALL CRAFT
ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DJB
NEAR TERM...DJB
SHORT TERM...DJB
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
920 AM CDT TUE OCT 23 2012
.DISCUSSION.../ISSUED AT 920 AM CDT/
DENSE FOG PERSISTING ACROSS NORTHEAST QUARTER OF THE FORECAST AREA
LONGER THAN EARLIER ANTICIPATED. FOR NOW...HAVE EXTENDED DENSE FOG
ADVISORY FOR SOUTHWEST MINNESOTA AND I-29 CORRIDOR FROM SIOUX FALLS
NORTHWARD UNTIL 10 AM...THOUGH HRRR SUGGESTS LOW VISIBILITY MAY LAST
EVEN LONGER THAN THAT...ESPECIALLY ALONG AND WEST/UPSLOPE OF BUFFALO
RIDGE. WILL CONTINUE TO EVALUATE THAT OVER THE NEXT HOUR AND ADJUST
AGAIN IF NECESSARY PRIOR TO 15Z. FOG/STRATUS WILL HOLD TEMPERATURES
DOWN ACCORDINGLY...AND HAVE BEGUN TO TREND AFTERNOON READINGS LOWER
ACROSS THE NORTHEAST CWA...THOUGH AGAIN...FURTHER ADJUSTMENTS MAY BE
NECESSARY IF FOG PERSISTS LATER INTO THE MORNING. LEFT HIGHS IN THE
70S ALONE ACROSS THE SOUTHWEST CWA...AS MODELS STILL SHOW BOUNDARY
AND ASSOCIATED SHIFT TO SOUTHWEST LOW LEVEL FLOW PUSHING INTO THAT
AREA DURING THE AFTERNOON. THIS SHOULD ALLOW DECENT DRYING/MIXING IN
AREAS WEST OF THE JAMES VALLEY.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
AVIATION FORECAST FOR THE TAF SITES CONTINUE TO SHOW BELOW NORMAL
CONFIDENCE IN THE DETAILS. OBSERVATION HAS DROPPED OUT AT KHON AND
WEB CAMS DO NOT SHOW FOG HAS SET IN THERE. SATELLITE INDICATES LOWER
CLOUDS HAVE WORKED INTO THE AREA...BUT NOT SURE AT WHAT HEIGHT. AS
SUCH...HAVE ADDED NO AMENDMENT NOTE TO KHON TAF UNTIL OBSERVATION
EQUIPMENT IS FIXED. WIDESPREAD DENSE FOG HAS SET IN EAST OF THE
JAMES RIVER VALLEY IN EASTERN SOUTH DAKOTA INTO SOUTHWEST MINNESOTA
AND NORTHWEST IOWA. FOG AND LOW CEILINGS WILL BE STUBBORN TO LEAVE
AHEAD OF AN APPROACHING COLD FRONT...AND MOST LIKELY WILL NOT MIX
OUT AT KSUX. KFSD WAS A TOUGH CALL BUT FOR NOW HAVE THEM BREAKING
OUT IMMEDIATELY AHEAD OF THE FRONT. IF TRENDS CONTINUES...THE BREAK
IN MVFR TO IFR CONDITIONS MAY NOT COME TILL AFTER 24/03Z WHEN THE
COLD FRONT MOVES THROUGH. LIGHT NORTH FLOW TRANSITIONING TO
NORTHEAST IS EXPECTED BEHIND THE FRONT.
&&
.PREV DISCUSSION.../ISSUED AT 420 AM CDT/
BROAD SWATH OF STRATUS BLANKETING MUCH OF THE NORTHERN AND CENTRAL
PLAINS REMAINS THE PRIMARY CONCERN FOR TODAY. MODELS HOLD ONTO THE
LOW LEVEL MOISTURE THROUGH MUCH OF THE MORNING RESULTING IN THE
WIDESPREAD LOW CLOUDS AND PATCHY DRIZZLE AND FOG WILL LIKELY STICK
AROUND THROUGH MID TO LATE MORNING. SOUTHWESTERLY FLOW WILL BEGIN TO
INCREASE ACROSS THE WEST LATER THIS MORNING WHICH SHOULD BEGIN
MIXING DRIER AIR INTO THE LOW LEVELS WHICH SHOULD SCOUR OUT THE
CLOUDS BY AFTERNOON. THE BIG QUESTION IS HOW QUICKLY THE CLEARING
WILL WORK INTO OUR EASTERN HALF AND WHETHER OUR FAR NORTHEAST WILL
SEE SIGNIFICANT CLEARING BY LATE AFTERNOON. THIS WILL LARGE
IMPLICATIONS ON TEMPERATURE TRENDS...AS HEFTY WARM AIR ADVECTION
WILL EASILY PLACE HIGH TEMPERATURES IN THE MID TO UPPER 70S IN THE
WEST. DID KNOCK BACK HIGHS SLIGHTLY TO THE UPPER 60S IN OUR
NORTHEAST GIVEN THE POTENTIAL TO BE CLOUDY FOR THE BETTER PART OF
THE DAYLIGHT HOURS.
THE MILDER TEMPERATURES WILL BE SHORT LIVED AS A LARGE UPPER LEVEL
LOW TRACKS INTO THE SOUTHERN CANADIAN PRAIRIE PROVINCES BY WEDNESDAY
AND DROPS A COLD FRONT THROUGH THE NORTHERN PLAINS. THE SURFACE
FRONT DIGS THROUGH THE FORECAST AREA TUESDAY AFTERNOON AND TUESDAY
NIGHT THEN STALLS JUST SOUTH OF THE FORECAST AREA WITH LITTLE IMPACT
OUTSIDE OF SOME INCREASED CLOUD COVERAGE. ON WEDNESDAY...SURFACE LOW
PRESSURE DEVELOPS IN EASTERN KANSAS AND PUSHES NORTHEAST INTO
WESTERN IOWA LATE IN THE DAY. THE PRECISE TIMING OF THIS FEATURE AND
THE POTENTIAL LIFTING OF THE WARM FRONT INTO OUR SOUTHEASTERN
COUNTIES ARE STILL A BIT UNCERTAIN. HOWEVER...WITH INCREASED SHEAR
AND NAM MUCAPE APPROACHING 2000 J/KG NEAR THE BOUNDARY...COULD SEE
SOME THUNDERSTORM ACTIVITY IN ADDITION TO SHOWERS. A LARGE DETERRENT
TO ANY SURFACED BASED/SEVERE CONVECTION WILL BE THE STRONG CAPPING
IN PLACE IN THIS AREA. A SECOND AREA TO WATCH FOR POTENTIAL
PRECIPITATION ON WEDNESDAY WILL BE ACROSS THE FAR WESTERN CWA...WITH
STRONG 850 MB FRONTOGENESIS SETTING UP ACROSS CENTRAL AND
NORTHEASTERN SOUTH DAKOTA. WILL KEEP CHANCEY POPS IN PLACE FOR THE
DAY WITH LARGE UNCERTAINTY WITH THE BOUNDARY PLACEMENTS AND
CONDITIONAL CONVECTIVE POTENTIAL.
THE MID LEVEL TROUGH STARTS KICKING EASTWARD WEDNESDAY NIGHT WITH
THE MID LEVEL FRONTOGENESIS SHIFTING INTO OUR CENTRAL CWA BY
DAYBREAK THURSDAY. IT LOOKS LIKE A VERY STRONG POTENTIAL FOR SOME
DECENT RAINFALL WEDNESDAY NIGHT AND EARLY THURSDAY AND HAVE BOOSTED
POPS TO CATEGORICAL FOR THE CENTRAL AND EASTERN CWA. RAINFALL
AMOUNTS OF AROUND A QUARTER TO HALF INCH LOOK REASONABLE AT THIS
POINT. MUCH COOLER TEMPERATURES WILL ARRIVE DURING THIS TIME...WITH
TEMPERATURES ON THURSDAY SHOWING LITTLE TO NO DIURNAL CHANGE OR EVEN
SOME FALLING TEMPERATURES. HIGHS WILL BE IN THE 40S.
IN THE EXTENDED...BROAD UPPER LEVEL TROUGHING SETTLES OVER THE
CENTRAL STATES AND WILL KEEP COOL AND DRY CONDITIONS IN PLACE INTO
THE END OF THE WEEK. MODELS ARE IN DECENT AGREEMENT WITH THIS DRY
AND COLD PATTERN WHICH PLACE WITH HIGHS ONLY IN THE UPPER 30S TO MID
40S AND LOWS IN THE 20S. MODELS DO DIVERGE A BIT FOR THE WEEKEND
WITH A MORE ZONAL MID LEVEL PATTERN IN THE GFS BRINGING A WAVE
THROUGH THE MISSOURI VALLEY ON SUNDAY. MEANWHILE THE ECMWF ALSO
HINTS AT A WAVE...BUT DROPS IT THROUGH SOUTHWEST MINNESOTA. DID ADD
A SLIGHT CHANCE POP IN OUR NORTHEAST FOR SUNDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ071-072-
080-081-089-090-097-098.
NE...NONE.
SD...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR SDZ040-056-
062.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
631 AM CDT TUE OCT 23 2012
.SHORT TERM...TODAY THROUGH THURSDAY
350 AM CDT TUE OCT 23 2012
AT 3 AM...A WARM FRONT EXTENDED FROM SIOUX CITY IOWA /KSUX/ TO
MUSCATINE IOWA /KMUT/. THERE IS LITTLE WEATHER ASSOCIATED WITH
THIS FRONT. MEANWHILE FURTHER NORTH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WERE DEVELOPING ALONG A BAND OF 900 TO 800 MB
FRONTOGENESIS ACROSS SOUTHEAST MINNESOTA. THE RUC SHOWS THAT THIS
BAND OF FRONTOGENESIS LIFTS QUICKLY NORTHEAST OF THE INTERSTATE 90
CORRIDOR AND BY LATE MORNING IT EXTENDS FROM HUDSON WISCONSIN TO
MILWAUKEE. THE MESO MODELS SEEM TO HAVE A FAIRLY GOOD HANDLE ON
THIS...SO FOLLOWED THEM. FURTHER SOUTHEAST...A SHORT WAVE TROUGH
WILL BE LIFTING NORTHEAST THROUGH THE MID MISSISSIPPI RIVER VALLEY
INTO THE LOWER GREAT LAKES. THERE IS MODERATE 850 MB MOISTURE INTO
PARTS OF OF NORTHEAST IOWA AND SOUTHWEST WISCONSIN THROUGHOUT THIS
MORNING...SO KEPT A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS
IN THESE AREAS THROUGHOUT THIS MORNING.
FOR THIS AFTERNOON...WEAK 300K ISENTROPIC LIFT CONTINUES NORTH OF
THE WARM FRONT NORTH OF THE INTERSTATE 94 CORRIDOR. AS A
RESULT...KEPT ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST
FOR THIS AREA.
FOR TONIGHT...THE 23.00Z MODELS ARE IN GENERAL AGREEMENT THAT
THERE WILL BE WEAK TO MODERATE 850 MOISTURE TRANSPORT INTO THE
REGION. THE MESO MODELS /ARW...NMM...AND SPC WRF/ SUGGEST THAT
THERE WILL BE SOME ISOLATED SHOWERS AND THUNDERSTORMS...SO KEPT
THE 20 PERCENT PROBABILITY OF RAIN ACROSS THE ENTIRE AREA.
ON WEDNESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT A WARM AIR
MASS BETWEEN 850 MB AND 675 MB WILL ADVECT NORTHWARD IN ADVANCE OF
AN APPROACHING COLD FRONT. THIS CAP SHOULD GREATLY INHIBIT THE
DEVELOPMENT OF PRECIPITATION AHEAD OF THE APPROACHING COLD FRONT
FOR MUCH OF THE DAY...THUS WENT DRY IN THE MORNING...AND SLOWLY
INCREASED THE PRECIPITATION CHANCES ACROSS NORTHEAST
IOWA...SOUTHEAST MINNESOTA...AND WEST-CENTRAL AND NORTH-CENTRAL
WISCONSIN. THINKING THAT THE STRONG CAP WILL LIMIT ANY SHOWER AND
THUNDERSTORM DEVELOPMENT TO ALONG AND JUST AHEAD OF THE COLD
FRONT. THE 0-6 KM BULK SHEAR IS FAVORABLE FOR THE DEVELOPMENT OF
SUPERCELL THUNDERSTORM DEVELOPMENT. THE GFS GENERATES SOME LIGHT
SHOWERS AHEAD OF THIS FRONT...THUS...ITS MLCAPES ARE RUNNING
BETWEEN 1000 AND 1500 J/KG. MEANWHILE THE NAM/WRF IS DRY AND
ALLOWS TEMPERATURES TO CLIMB TO AROUND 80. THE COMBINATION OF
THESE TEMPERATURES AND MID 60 DEW POINTS /HIGHEST THIS LATE IN THE
YEAR SINCE OCTOBER 26 2010/ WILL RESULT IN THE ML CAPES AROUND
2500 J/KG. INITIALLY THINKING THAT THE CONVECTION WILL START TO
DEVELOP ALONG THE FRONT BETWEEN 24.19 AND 24.21Z AS ELEVATED CELLS
AND THEN BECOME SURFACE BASED BETWEEN 24.21Z AND 25.00Z. THE NAM
HAS A WEAK LOW ALONG THIS FRONT WHICH HELPS INCREASE THE 0-1KM
BULK SHEAR WHICH MAY POSSIBLY RESULT IN ISOLATED TORNADOES ACROSS
NORTH-CENTRAL IOWA AND SOUTH-CENTRAL AND SOUTHEAST MINNESOTA.
OTHERWISE...THE MAIN SEVERE WEATHER THREATS WILL BE LARGE HAIL AND
DAMAGING WIND DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS
NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND WEST-CENTRAL WISCONSIN.
ON THURSDAY...THE MODELS STILL DIFFER ON THE TIMING OF THE FRONT.
THE GFS IS THE SLOWEST AND LINGER PRECIPITATION ACROSS THE ENTIRE
AREA THROUGH THE DAY. MEANWHILE THE GEM IS THE FASTEST AND HAS THE
AFTERNOON DRY. DUE TO THESE DIFFERENCES...DID NOT GET TOO FANCY
WITH TRYING TO TIME THE PRECIPITATION OUT OF THE AREA.
REGARDLESS...THE MOST NOTICEABLE FEATURE WILL BE THE RAPIDLY
FALLING TEMPERATURES IN THE WAKE OF THE FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
350 AM CDT TUE OCT 23 2012
ON THURSDAY NIGHT...THE MODELS WERE IN GOOD CONSENSUS THAT THE
PRECIPITATION WOULD BE ENDING ACROSS WESTERN WISCONSIN DURING THE
EVENING. AS A RESULT...CONFINED THE PRECIPITATION CHANCES TO THAT
TIME PERIOD.
ON MONDAY...THE 23.00Z GFS WAS VERY SIMILAR WITH ITS 22.18Z RUN AT
GENERATING SOME WARM AIR ADVECTION PRECIPITATION ACROSS THE AREA.
MEANWHILE THE ECMWF CONTINUE TO SHOW THAT THIS PRECIPITATION WILL
DRY UP AS IT HEADS INTO THE AREA. DUE TO THESE DIFFERENCES
MENTIONED A SLIGHT CHANCE OF PRECIPITATION NORTH OF AN OELWEIN
IOWA TO MEDFORD WISCONSIN LINE. THE PRECIPITATION HAS THE
POTENTIAL OF BEING A MIX OF RAIN AND SNOW IN THE EARLY MORNING.
HOWEVER SINCE IT WAS VERY UNCLEAR IT WAS EVEN GOING TO
OCCUR...JUST OPTED TO GO WITH RAIN FOR NOW.
&&
.AVIATION...TODAY AND TONIGHT
630 AM CDT TUE OCT 23 2012
A WARM FRONT CURRENTLY DRAPED ACROSS CENTRAL IOWA WILL LIFT
NORTHWARD TODAY. IFR CEILINGS/VISIBILITIES COMMON TO THE NORTH OF
THE FRONT AT BOTH TAF SITES. EXPECT THESE CONDITIONS TO CONTINUE
THROUGH MID MORNING...BEFORE CEILINGS AND VISIBILITIES IMPROVE.
CEILING HEIGHTS ARE EXPECTED TO RISE INTO THE MVFER CATEGORY
BETWEEN 14Z-16Z AND REMAIN THERE THROUGH THE REMAINDER OF THE TAF
PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
350 AM CDT TUE OCT 23 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
920 AM MDT TUE OCT 23 2012
.UPDATE...
WENT AHEAD AND LET THE HIGH WIND WARNING EXPIRE THIS MORNING AS
OBSERVED WINDS HAVE STAYED DOWN BELOW WARNING CRITERIA. THERE IS
STILL A CHANCE FOR WINDS TO BECOME STRONG AS WE MIX OUT...BUT DO
NOT THINK WE WILL HIT HIGH WIND WARNING CRITERIA ANY MORE TODAY.
STILL FAIRLY DENSE FOG OUT IN THE PANHANDLE AND WILL CONTINUE THE
SPS WE HAVE GOING THROUGH NOON. FOG MAY BURN OFF EARLIER THAN
THAT...BUT FOR NOW...WILL GO FOR NOON. DEFINITELY SOME QUESTIONS
ON THE UPCOMING WINTER EVENT THAT WE WILL NEED TO WORK OUT FOR THE
AFTERNOON PACKAGE. WAITING FOR THE 12Z MODEL RUNS TO MAKE ANY
DECISIONS ON HIGHLIGHTS.
CLAYCOMB
&&
.PREV DISCUSSION... /ISSUED 623 AM MDT TUE OCT 23 2012/
SHORT TERM...TODAY THROUGH THURSDAY...
LOTS OF FORECAST CONCERNS OVER THE SHORT TERM. WINDS HAVE BEEN
APPROACHING HIGH WIND CRITERIA IN THE ARLINGTON AREA OVER THE PAST
FEW HOURS...BUT HAVE GENERALLY REMAINED BELOW 50MPH. THE GFS SHOWS
700MB 50-60 KTS TO THE WEST OF THE LARAMIE RANGE THROUGH 12Z
BEFORE DECREASING TO 45 KTS BY 18Z. BELIEVE THAT THE LACK OF
MIXING IS KEEPING WIND GUSTS BELOW 50 KTS DESPITE THE FAVORABLE
SFC PRESSURE PATTERN AND STRONG WINDS JUST OFF THE SFC. WILL KEEP
THE HIGH WIND WARNING GOING THROUGH THE MORNING BUT CONDITIONS ARE
CURRENTLY LOOKING MARGINAL FOR WIDESPREAD HIGH WINDS OUTSIDE OF
ARLINGTON. THE SFC LOW CURRENTLY OVER NORTHERN WYOMING IS PROGGED
TO SHIFT EASTWARD INTO WESTERN SOUTH DAKOTA BY MIDDAY. THIS WILL
CAUSE LLVL FLOW TO GO MORE WESTERLY...BUT STILL EXPECT BREEZY-
TO-WINDY CONDITIONS TO CONTINUE ALONG AND WEST OF THE LARAMIE
RANGE WITH 700MB FLOW AT THE AFOREMENTIONED 30-40 KTS.
LOW CLOUDS AND FOG HAVE DEVELOPED OVER THE WESTERN NEBRASKA
PANHANDLE EARLY THIS MORNING. THE HRRR MODEL SHOWS LIFR CONDITIONS
PERSISTING THROUGH AROUND 15Z. SOME LOCATIONS ACROSS THE SOUTHERN
PANHANDLE HAVE REPORTED DENSE FOG. CURRENTLY HAVE AN SPS OUT TO
COVER THE DENSE FOG THREAT BUT MAY NEED TO CONSIDER AN ADVISORY IF
THE CONDITIONS PERSIST. WATER VAPOR IMAGERY SHOWS THE STRONG UPPER
LEVEL TROUGH CURRENTLY OVER THE WEST COAST WITH THE MOISTURE
STREAMING ACROSS WESTERN WY. THIS TROUGH WILL PROGRESS EASTWARD
OVER THE COURSE OF THE DAY WITH THE MOISTURE AND LIFT PRODUCING A
SLIGHT CHANCE OF SHOWERS OVER THE WESTERN ZONES BY AFTERNOON.
THE MAIN FORECAST CHALLENGE OVER THE SHORT TERM INVOLVES THE
POTENTIAL MAJOR WINTER STORM EVENT BEGINNING ON WEDNESDAY. THE
MODELS ARE IN AGREEMENT IN SHOWING THE LARGE SCALE TROUGH AXIS
BEING LOCATED OVER UTAH AND IDAHO ON WEDNESDAY AFTERNOON. A 125 KT
UPPER LEVEL JET IS SITUATED OVER WYOMING ON WEDNESDAY. A SW-NE
ORIENTED MIDLEVEL FRONTOGENESIS LINE DEVELOPS FROM RAWLINS TO
DOUGLAS BY MIDDAY WEDNESDAY. SNOW BECOMES LIKELY TO THE WEST OF THE
LARAMIE RANGE ON WEDNESDAY MORNING WITH 700MB TEMPS AROUND -4C. A
STRONG SHORTWAVE IN THE TROUGH IS FORECASTED TO MOVE OVER COLORADO
ON WEDNESDAY NIGHT. INCREASING LARGE SCALE LIFT AND UPPER LEVEL
DIVERGENCE WILL CAUSE WIDESPREAD SNOW TO DEVELOP MAINLY AFTER 00Z
THURS OVER THE PLAINS. IT IS THE 00Z-12Z PERIOD THAT SNOWFALL
RATES WILL BE HIGHEST IN SOUTHEAST WYOMING WITH EXCELLENT LARGE
SCALE UPWARD MOTION AND DEEP LAYERED SATURATION. THE SHORTWAVE
QUICKLY PROGRESSES EASTWARD INTO THE CENTRAL PLAINS ON THURS
MORNING WITH SNOWFALL RATES COMING DOWN SUBSTANTIALLY. THURS WILL
BE QUITE COLD FOR LATE OCTOBER WITH LLVL UPSLOPE AND 700MB TEMPS
AROUND -10C. WITH A LACK OF LARGE SCALE FORCING ON THURS...LIGHT
SNOW SHOWERS WILL LIKELY BE CONFINED TO THE MTNS AND FAVORED
UPSLOPE AREAS ALONG THE LARAMIE RANGE.
WITH REGARD TO WINTER WEATHER HIGHLIGHTS...DECIDED TO ISSUE A
WINTER STORM WATCH FOR AREAS ALONG THE LARAMIE RANGE AND THE
SIERRA MADRE AND SNOWY RANGES. HAVE THE WATCH CONTINUING THROUGH
THE 00Z FRI AS LIGHT SNOW WILL LIKELY CONTINUE THROUGH THURS
AFTN OVER THE HIGHER ELEVATIONS. FUTURE SHIFTS CAN DECIDE IF THE
HIGHLIGHTS SHOULD BE ENDED OVER LOWER ELEVATIONS AFTER THE
SNOWFALL RATES COME DOWN ON THURS MORNING AS THE MODELS ARE
SHOWING. SNOWFALL ACCUMULATIONS WILL LIKELY BE ON THE LOW END OF
WARNING CRITERIA WITH THIS EVENT. WINDS WILL NOT BE MUCH OF A
CONCERN WITH THIS SYSTEM...HOWEVER OCCASIONAL GUSTS TO 35 MPH WILL
BE POSSIBLE AS THE COLD FRONT MOVES ACROSS THE PLAINS ON WED
EVENING. MUCH WEAKER WINDS CWA-WIDE ON THURS AS THE SFC HIGH
PRESSURE SETTLES OVER THE PLAINS.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
LATEST MEDIUM RANGE MODEL OUTPUT OFFER FAIRLY SIMILAR SOLUTIONS
THROUGH THE WEEKEND WITH SOME DIVERGENCE NOTED EARLY NEXT WEEK.
INITIALLY...A TRAILING SHORTWAVE WILL ROUND THE BASE OF THE BROAD
TROUGH FROM NRN UTAH INTO COLORADO THURSDAY NIGHT.
MEANWHILE...UPSLOPE FLOW WILL PERSIST IN THE LLVLS PARTICULARLY FOR
LOCATIONS NEAREST THE LARAMIE RANGE. SO...WOULD EXPECT ANOTHER BOUT
OF LIGHT SNOW ON THURSDAY NIGHT ADDING ANOTHER INCH OR TWO TO THE
THE SNOWFALL TOTALS.
THE SHORTWAVE WILL ACCELERATE EAST OUT ONTO THE PLAINS FOR
FRIDAY...LEAVING NORTHWEST FLOW TO PREVAIL ACROSS THE CWFA. THERE
MAY BE SOME LIGHT SNOW OR FLURRIES CONTINUING MAINLY FOR OROGRAPHIC
AREAS ON FRIDAY MORNING...WITH A GRADUAL DRYING TREND DURING THE
AFTERNOON. TEMPERATURES WILL CONTINUE TO BE COLD ON FRIDAY WITH H7
TEMPERATURES REMAINING AROUND -10C. THIS WILL KEEP HIGH TEMPERATURES
IN THE 30S ACROSS THE AREA. FRANKLY WITH SNOW ON THE GROUND WOULD
NOT BE AT ALL SURPRISED TO ONLY SEE 20S AT SOME AREAS ON FRIDAY.
ON SATURDAY...THE LATEST GFS TRACKING ANOTHER SHORTWAVE INTO THE
AREA IN NORTHWEST FLOW. THE ECMWF/UKMET/GEM/GFES DO NOT SUPPORT SUCH
A SOLUTION...SO HAVE CONSIDER IT TO BE THE OUTLIER AND HAVE
DISCOUNTED. AS SUCH A DRY DAY IS IN STORE ON SATURDAY WITH
TEMPERATURES THAT WILL CLIMB INTO THE 30S AND 40S. WINDS WILL
INCREASE FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE AS LLVL
GRADIENT TIGHTENS. SO EVEN THOUGH TEMPERATURES WILL BE SLIGHTLY
WARMER...THE WINDS WILL MAKE IT FEEL MUCH COOLER IN THESE AREAS.
NORTHWEST FLOW WILL CONTINUE ON SUNDAY. BUT THE ECMWF IS SHOWING THE
EARLY SIGNS OF ANTICYLONIC FLOW DEVELOPING OVER THE AREA BY LATE
SUNDAY. COMPARATIVELY THE GFS MAINTAINS NORTHWEST FLOW OVR THE AREA
AS A RESULT OF A STRONGER TROUGH OVER WRN CANADA. THE GEM/UKMET
SOLUTIONS OVER A REASONABLE COMPROMISE BETWEEN THE GFS/ECMWF. IN ANY
CASE...EXPECT CONDITIONS TO REMAIN DRY WITH TEMPERATURES MODERATING
BACK INTO THE 50S AND 60S FOR THE SUNDAY THROUGH TUESDAY TIMEFRAME.
AVIATION...12Z TAF ISSUANCE...
MAIN AVIATION CONCERN WILL BE THE FOG...SOME OF WHICH HAS BEEN
LOCALLY DENSE THAT HAS DEVELOPED ACROSS THE WESTERN NEBRASKA
AIRFIELDS THIS MORNING. THESE LOW CIGS WILL HANG ON UNTIL AROUND
15 OR 16Z BEFORE LIFTING. SE WYOMING TERMINALS WILL HAVE GUSTY
WINDS TO CONTEND WITH BY LATE THIS MORNING AND MORE SO DURING THE
AFTERNOON TIMEFRAME. EXPECT TO SEE THESE GUSTS APPROACH 30 OR 40
KNOTS THROUGH THIS PERIOD. SNOW WILL DEVELOP AT KRWL AFTER 03Z OR
SO...AS THE NEXT STORM SYSTEM BEGINS TO IMPACT THE REGION.
FIRE WEATHER...
A WINDY START TO THE DAY FOR AREAS WEST ALONG AND WEST OF THE
LARAMIE RANGE TODAY...AS GUSTS OF 40 TO 50 MPH HAVE BEEN COMMON.
THESE WINDS WILL CONTINUE THROUGH MUCH OF THE DAY BEFORE RELAXING
THIS EVENING AND OVERNIGHT. MEANWHILE...FOGGY CONDITIONS ACROSS THE
WESTERN PANHANDLE WILL PERSIST THROUGH MID/LATE MORNING BEFORE
LIFTING. ONE MORE WARM DAY IS IN STORE TODAY WITH HIGH TEMPERATURES
THAT WILL REACH THE 50S WEST OF THE LARAMIE RANGE AND 60S AND 70S
OUT ON THE EASTERN PLAINS. BIG CHANGES ARE ON THE WAY TOMORROW
HOWEVER...AS A COLD FRONT BEGINS TO PUSH THROUGH THE AREA.
PRECIPITATION WILL TRANSITION FROM RAIN TO SNOW THROUGH THE DAY AS
THE FRONT PROGRESSES SOUTH. PRECIPITATION WILL TURN TO ALL SNOW FOR
WEDNESDAY NIGHT AND THURSDAY. SIGNIFICANT ACCUMULATING SNOW IS
LOOKING INCREASINGLY POSSIBLE. MUCH COLDER AIR WILL FILTER IN FOR
THURSDAY AND FRIDAY AS WELL...WITH HIGHS ONLY CLIMBING INTO THE 20S
AND 30S.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM 6 AM WEDNESDAY TO 6 PM THURSDAY FOR
WYZ103-WYZ105-WYZ110-WYZ112-WYZ114.
WINTER STORM WATCH FROM 6 PM WEDNESDAY TO 6 PM THURSDAY FOR
WYZ106-WYZ115-WYZ116-WYZ117-WYZ118.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...FINCH
LONG TERM/AVIATION...HAHN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
623 AM MDT TUE OCT 23 2012
.SHORT TERM...TODAY THROUGH THURSDAY...
LOTS OF FORECAST CONCERNS OVER THE SHORT TERM. WINDS HAVE BEEN
APPROACHING HIGH WIND CRITERIA IN THE ARLINGTON AREA OVER THE PAST
FEW HOURS...BUT HAVE GENERALLY REMAINED BELOW 50MPH. THE GFS SHOWS
700MB 50-60 KTS TO THE WEST OF THE LARAMIE RANGE THROUGH 12Z
BEFORE DECREASING TO 45 KTS BY 18Z. BELIEVE THAT THE LACK OF
MIXING IS KEEPING WIND GUSTS BELOW 50 KTS DESPITE THE FAVORABLE
SFC PRESSURE PATTERN AND STRONG WINDS JUST OFF THE SFC. WILL KEEP
THE HIGH WIND WARNING GOING THROUGH THE MORNING BUT CONDITIONS ARE
CURRENTLY LOOKING MARGINAL FOR WIDESPREAD HIGH WINDS OUTSIDE OF
ARLINGTON. THE SFC LOW CURRENTLY OVER NORTHERN WYOMING IS PROGGED
TO SHIFT EASTWARD INTO WESTERN SOUTH DAKOTA BY MIDDAY. THIS WILL
CAUSE LLVL FLOW TO GO MORE WESTERLY...BUT STILL EXPECT BREEZY-
TO-WINDY CONDITIONS TO CONTINUE ALONG AND WEST OF THE LARAMIE
RANGE WITH 700MB FLOW AT THE AFOREMENTIONED 30-40 KTS.
LOW CLOUDS AND FOG HAVE DEVELOPED OVER THE WESTERN NEBRASKA
PANHANDLE EARLY THIS MORNING. THE HRRR MODEL SHOWS LIFR CONDITIONS
PERSISTING THROUGH AROUND 15Z. SOME LOCATIONS ACROSS THE SOUTHERN
PANHANDLE HAVE REPORTED DENSE FOG. CURRENTLY HAVE AN SPS OUT TO
COVER THE DENSE FOG THREAT BUT MAY NEED TO CONSIDER AN ADVISORY IF
THE CONDITIONS PERSIST. WATER VAPOR IMAGERY SHOWS THE STRONG UPPER
LEVEL TROUGH CURRENTLY OVER THE WEST COAST WITH THE MOISTURE
STREAMING ACROSS WESTERN WY. THIS TROUGH WILL PROGRESS EASTWARD
OVER THE COURSE OF THE DAY WITH THE MOISTURE AND LIFT PRODUCING A
SLIGHT CHANCE OF SHOWERS OVER THE WESTERN ZONES BY AFTERNOON.
THE MAIN FORECAST CHALLENGE OVER THE SHORT TERM INVOLVES THE
POTENTIAL MAJOR WINTER STORM EVENT BEGINNING ON WEDNESDAY. THE
MODELS ARE IN AGREEMENT IN SHOWING THE LARGE SCALE TROUGH AXIS
BEING LOCATED OVER UTAH AND IDAHO ON WEDNESDAY AFTERNOON. A 125 KT
UPPER LEVEL JET IS SITUATED OVER WYOMING ON WEDNESDAY. A SW-NE
ORIENTED MIDLEVEL FRONTOGENESIS LINE DEVELOPS FROM RAWLINS TO
DOUGLAS BY MIDDAY WEDNESDAY. SNOW BECOMES LIKELY TO THE WEST OF THE
LARAMIE RANGE ON WEDNESDAY MORNING WITH 700MB TEMPS AROUND -4C. A
STRONG SHORTWAVE IN THE TROUGH IS FORECASTED TO MOVE OVER COLORADO
ON WEDNESDAY NIGHT. INCREASING LARGE SCALE LIFT AND UPPER LEVEL
DIVERGENCE WILL CAUSE WIDESPREAD SNOW TO DEVELOP MAINLY AFTER 00Z
THURS OVER THE PLAINS. IT IS THE 00Z-12Z PERIOD THAT SNOWFALL
RATES WILL BE HIGHEST IN SOUTHEAST WYOMING WITH EXCELLENT LARGE
SCALE UPWARD MOTION AND DEEP LAYERED SATURATION. THE SHORTWAVE
QUICKLY PROGRESSES EASTWARD INTO THE CENTRAL PLAINS ON THURS
MORNING WITH SNOWFALL RATES COMING DOWN SUBSTANTIALLY. THURS WILL
BE QUITE COLD FOR LATE OCTOBER WITH LLVL UPSLOPE AND 700MB TEMPS
AROUND -10C. WITH A LACK OF LARGE SCALE FORCING ON THURS...LIGHT
SNOW SHOWERS WILL LIKELY BE CONFINED TO THE MTNS AND FAVORED
UPSLOPE AREAS ALONG THE LARAMIE RANGE.
WITH REGARD TO WINTER WEATHER HIGHLIGHTS...DECIDED TO ISSUE A
WINTER STORM WATCH FOR AREAS ALONG THE LARAMIE RANGE AND THE
SIERRA MADRE AND SNOWY RANGES. HAVE THE WATCH CONTINUING THROUGH
THE 00Z FRI AS LIGHT SNOW WILL LIKELY CONTINUE THROUGH THURS
AFTN OVER THE HIGHER ELEVATIONS. FUTURE SHIFTS CAN DECIDE IF THE
HIGHLIGHTS SHOULD BE ENDED OVER LOWER ELEVATIONS AFTER THE
SNOWFALL RATES COME DOWN ON THURS MORNING AS THE MODELS ARE
SHOWING. SNOWFALL ACCUMULATIONS WILL LIKELY BE ON THE LOW END OF
WARNING CRITERIA WITH THIS EVENT. WINDS WILL NOT BE MUCH OF A
CONCERN WITH THIS SYSTEM...HOWEVER OCCASIONAL GUSTS TO 35 MPH WILL
BE POSSIBLE AS THE COLD FRONT MOVES ACROSS THE PLAINS ON WED
EVENING. MUCH WEAKER WINDS CWA-WIDE ON THURS AS THE SFC HIGH
PRESSURE SETTLES OVER THE PLAINS.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
LATEST MEDIUM RANGE MODEL OUTPUT OFFER FAIRLY SIMILAR SOLUTIONS
THROUGH THE WEEKEND WITH SOME DIVERGENCE NOTED EARLY NEXT WEEK.
INITIALLY...A TRAILING SHORTWAVE WILL ROUND THE BASE OF THE BROAD
TROUGH FROM NRN UTAH INTO COLORADO THURSDAY NIGHT.
MEANWHILE...UPSLOPE FLOW WILL PERSIST IN THE LLVLS PARTICULARLY FOR
LOCATIONS NEAREST THE LARAMIE RANGE. SO...WOULD EXPECT ANOTHER BOUT
OF LIGHT SNOW ON THURSDAY NIGHT ADDING ANOTHER INCH OR TWO TO THE
THE SNOWFALL TOTALS.
THE SHORTWAVE WILL ACCELERATE EAST OUT ONTO THE PLAINS FOR
FRIDAY...LEAVING NORTHWEST FLOW TO PREVAIL ACROSS THE CWFA. THERE
MAY BE SOME LIGHT SNOW OR FLURRIES CONTINUING MAINLY FOR OROGRAPHIC
AREAS ON FRIDAY MORNING...WITH A GRADUAL DRYING TREND DURING THE
AFTERNOON. TEMPERATURES WILL CONTINUE TO BE COLD ON FRIDAY WITH H7
TEMPERATURES REMAINING AROUND -10C. THIS WILL KEEP HIGH TEMPERATURES
IN THE 30S ACROSS THE AREA. FRANKLY WITH SNOW ON THE GROUND WOULD
NOT BE AT ALL SURPRISED TO ONLY SEE 20S AT SOME AREAS ON FRIDAY.
ON SATURDAY...THE LATEST GFS TRACKING ANOTHER SHORTWAVE INTO THE
AREA IN NORTHWEST FLOW. THE ECMWF/UKMET/GEM/GFES DO NOT SUPPORT SUCH
A SOLUTION...SO HAVE CONSIDER IT TO BE THE OUTLIER AND HAVE
DISCOUNTED. AS SUCH A DRY DAY IS IN STORE ON SATURDAY WITH
TEMPERATURES THAT WILL CLIMB INTO THE 30S AND 40S. WINDS WILL
INCREASE FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE AS LLVL
GRADIENT TIGHTENS. SO EVEN THOUGH TEMPERATURES WILL BE SLIGHTLY
WARMER...THE WINDS WILL MAKE IT FEEL MUCH COOLER IN THESE AREAS.
NORTHWEST FLOW WILL CONTINUE ON SUNDAY. BUT THE ECMWF IS SHOWING THE
EARLY SIGNS OF ANTICYLONIC FLOW DEVELOPING OVER THE AREA BY LATE
SUNDAY. COMPARATIVELY THE GFS MAINTAINS NORTHWEST FLOW OVR THE AREA
AS A RESULT OF A STRONGER TROUGH OVER WRN CANADA. THE GEM/UKMET
SOLUTIONS OVER A REASONABLE COMPROMISE BETWEEN THE GFS/ECMWF. IN ANY
CASE...EXPECT CONDITIONS TO REMAIN DRY WITH TEMPERATURES MODERATING
BACK INTO THE 50S AND 60S FOR THE SUNDAY THROUGH TUESDAY TIMEFRAME.
&&
.AVIATION...12Z TAF ISSUANCE...
MAIN AVIATION CONCERN WILL BE THE FOG...SOME OF WHICH HAS BEEN
LOCALLY DENSE THAT HAS DEVELOPED ACROSS THE WESTERN NEBRASKA
AIRFIELDS THIS MORNING. THESE LOW CIGS WILL HANG ON UNTIL AROUND
15 OR 16Z BEFORE LIFTING. SE WYOMING TERMINALS WILL HAVE GUSTY
WINDS TO CONTEND WITH BY LATE THIS MORNING AND MORE SO DURING THE
AFTERNOON TIMEFRAME. EXPECT TO SEE THESE GUSTS APPROACH 30 OR 40
KNOTS THROUGH THIS PERIOD. SNOW WILL DEVELOP AT KRWL AFTER 03Z OR
SO...AS THE NEXT STORM SYSTEM BEGINS TO IMPACT THE REGION.
&&
.FIRE WEATHER...
A WINDY START TO THE DAY FOR AREAS WEST ALONG AND WEST OF THE
LARAMIE RANGE TODAY...AS GUSTS OF 40 TO 50 MPH HAVE BEEN COMMON.
THESE WINDS WILL CONTINUE THROUGH MUCH OF THE DAY BEFORE RELAXING
THIS EVENING AND OVERNIGHT. MEANWHILE...FOGGY CONDITIONS ACROSS THE
WESTERN PANHANDLE WILL PERSIST THROUGH MID/LATE MORNING BEFORE
LIFTING. ONE MORE WARM DAY IS IN STORE TODAY WITH HIGH TEMPERATURES
THAT WILL REACH THE 50S WEST OF THE LARAMIE RANGE AND 60S AND 70S
OUT ON THE EASTERN PLAINS. BIG CHANGES ARE ON THE WAY TOMORROW
HOWEVER...AS A COLD FRONT BEGINS TO PUSH THROUGH THE AREA.
PRECIPITATION WILL TRANSITION FROM RAIN TO SNOW THROUGH THE DAY AS
THE FRONT PROGRESSES SOUTH. PRECIPITATION WILL TURN TO ALL SNOW FOR
WEDNESDAY NIGHT AND THURSDAY. SIGNIFICANT ACCUMULATING SNOW IS
LOOKING INCREASINGLY POSSIBLE. MUCH COLDER AIR WILL FILTER IN FOR
THURSDAY AND FRIDAY AS WELL...WITH HIGHS ONLY CLIMBING INTO THE 20S
AND 30S.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL 9 AM TUESDAY FOR WYZ104-WYZ105-WYZ106-
WYZ109-WYZ110.
WINTER STORM WATCH FROM 6 AM WEDNESDAY TO 6 PM THURSDAY FOR
WYZ103-WYZ105-WYZ110-WYZ112-WYZ114.
WINTER STORM WATCH FROM 6 PM WEDNESDAY TO 6 PM THURSDAY FOR
WYZ106-WYZ115-WYZ116-WYZ117-WYZ118.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM/AVIATION/FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1042 AM MDT TUE OCT 23 2012
.UPDATE...
ISSUED AT 1042 AM MDT TUE OCT 23 2012
PUBLIC REPORT THAT STRONG WINDS ARE BUFFETING VEHICLES NEAR RIDGWAY.
WITH REMOTE MOUNTAIN SITES IN THE NWRN SAN JUANS AND DOUGLAS PASS
INDICATING GUSTY WINDS...WILL EXPAND THE WIND ADVISORY TO INCLUDE
THESE AREAS. THESE REPORTS CONFIRM HRRR MODEL SURFACE WIND GUST
TRENDS THAT SHOW THE UNCOMPAHGRE RIDGE TOP INTO THE NWRN SAN
JUANS BEING THE BULLSEYE FOR STRONGEST WINDS.
UPDATE ISSUED AT 925 AM MDT TUE OCT 23 2012
WINDS CONTINUE TO BE PROBLEMATIC TODAY WITH GUSTS APPROACHING 45
MPH AT SEVERAL LOCATIONS. WITH TIGHT GRADIENT FLOW AND A WELL
MIXED LAYER (AT LEAST UP TO 600 MB FROM THE MORNING SOUNDING)...WINDS
FROM ALOFT WILL TRANSLATE TO THE SURFACE...ESPECIALLY WITH THE
BOUNDARY LAYER NEARLY DRY ADIABATIC. SURFACE WINDS HAVE BEEN
ERRATIC...ESPECIALLY ALONG THE I70 CORRIDOR...BUT LAMP GUIDANCE
SUGGEST THAT WINDS WILL BECOME EVEN MORE ERRATIC. HAVE ELECTED TO
ISSUE ANOTHER WIND ADVISORY FOR THE REMAINDER OF THE DAY. APPEARS
THAT WINDS WILL DECOUPLE FAIRLY QUICKLY THIS EVENING AS SURFACE
FRONT BEGINS TO SEEP INTO THE FORECAST AREA.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 409 AM MDT TUE OCT 23 2012
TODAY: PATTERN SHOWS ONLY SLIGHT CHANGE TODAY AS THE BROAD TROUGH
OVER THE PACIFIC COAST STAYS PUT. AS A RESULT...VIGOROUS SOUTHWEST
FLOW WILL CONTINUE ACROSS THE AREA. HOWEVER...BOTH GFS40 AND NAM12
INDICATED 7H HEIGHT GRADIENT WILL RELAX ACROSS THE AREA RESULTING
IN DECREASED WIND SPEED. CONSEQUENTLY...IT NOW APPEARS UNLIKELY
THAT WIND CRITERIA WILL BE MET THIS AFTERNOON AND THEREFORE
CANCELLED THE WIND ADVISORY FOR THIS AFTERNOON AND EVENING.
THE STATIONARY FRONT JUST NORTH OF THE FORECAST AREA OVER THE PAST
SEVERAL DAYS WILL SAG SOUTHWARD AS LOW PRESSURE MOVES EASTWARD
ACROSS THE NORTHERN PLAINS. THE BOUNDARY WILL COME TO REST NEAR
THE NORTHEAST UTAH/NORTHWEST COLORADO BORDER AREA THIS AFTERNOON.
LOW LEVEL CONVERGENCE ALONG THE BOUNDARY COMBINED WITH CHANNELED
VORTICITY ALOFT SHOULD FOCUS SHOWER ACTIVITY IN THIS AREA. ADDED
SOME ISOLATED THUNDERSTORMS ACROSS THE EXTREME NORTH DURING THE
AFTERNOON AS FORECAST SOUNDINGS INDICATED THE ATMOSPHERE TO BE
CONDITIONALLY UNSTABLE IN THE VICINITY OF THE FRONTAL BOUNDARY.
ADVECTION OF COOLER AIR ACROSS THE NORTHERNMOST ZONES WILL RESULT
IN ABOUT 5 DEGREES OF COOLING TODAY WHILE TEMPERATURES SHOULD BE
LARGELY UNCHANGED SOUTH. FELT MAV MOS WAS A BIT AGGRESSIVE WITH
THE COOLING ACROSS THE NORTH SO HEWED CLOSER TO THE MET GUIDANCE.
TONIGHT-THURSDAY: COMPLICATED PATTERN WILL EVOLVE AS ENERGY
CONTINUES TO EJECT FROM THE PACIFIC LOW PRESSURE SYSTEM
TONIGHT...BEFORE THE MAIN TROUGH SHIFTS EAST OVER THE WESTERN
CONUS WED THROUGH THU.
A SURFACE FRONT WILL GENERALLY REMAIN STALLED ALONG...AND JUST TO
THE NORTH OUR THE CWA BORDER TONIGHT. SO THROUGHOUT THE NIGHT WE
SHOULD CONTINUE TO SEE A FEW SHOWERS OVER NORTHEAST UT AND FAR
NORTHWEST CO ALONG AND JUST TO THE SOUTH OF THIS BAROCLINIC ZONE.
ALSO CANNOT RULE OUT THE POSSIBILITY OF A FEW LIGHTNING STRIKES.
THE GRADIENT WILL REMAIN TIGHT ACROSS THE ENTIRE AREA. SO GUSTY
WINDS WILL CONTINUE OVER EXPOSED HIGHER TERRAIN...BUT ESPECIALLY
ALONG THE CO/WY BORDER. WINDS IN THE VALLEYS SHOULD DIMINISH BY OR
SHORTLY AFTER SUNSET AS THE AIR MASS DECOUPLES. NIGHTTIME
TEMPERATURES WILL REMAIN VERY MILD DUE TO THE UNSETTLED NATURE OF
THE PATTERN.
THE FRONT WILL FINALLY DROP SOUTHWARD AND INTO THE AREA EARLY WED
AS THE MAIN UPPER PATTERN SHIFTS EAST. THE FRONT WILL THEN
PROCEED SOUTHWARD THROUGH THE DAY...REACHING THE I-70 CORRIDOR
EARLY TO MID AFTERNOON AND TO THE SOUTHERN BORDER LATE AFTERNOON
TO EARLY EVENING. WINDS WILL AGAIN MIX INTO THE LOWER ELEVATIONS
EARLY IN THE DAY AHEAD OF THE FRONT...AND DUE TO THE CONTINUED
TIGHT GRADIENT RESULTING FROM THE APPROACHING TROUGH. THE CHANCE
FOR SHOWERS...AND A FEW THUNDERSTORMS...WILL ALSO SPREAD TO THE
SOUTH. HOWEVER MODELS INDICATE THAT MOISTURE WILL BE SOMEWHAT
LIMITED ACROSS OUR CWA AS THIS SYSTEM PASSES...ESPECIALLY OVER THE
SOUTHERN PORTION. THAT SAID...MODELS CONTINUE TO SHOW GOOD UPPER
LEVEL SUPPORT WITH THE NOSE OF THE 120+ JET CORE RAKING THE AREA
THROUGH THE DAY. INSTABILITY ALSO INCREASES AS TEMPS AT 500 MB
DROP FROM AROUND -15C AT GJT WED MORNING TO AROUND -20C IN THE
AFTERNOON. THEN AS THE MAIN TROUGH AXIS PASSES WED NIGHT 500 MB
TEMPS DROP TO -26 AT GJT BY 12Z THU. THEN ON THU...A REINFORCING
COLD SHOT WILL APPROACH FROM THE NORTHWEST TO KEEP THE AIR MASS
UNSETTLED...AND SNOW ONGOING OVER THE NORTHERN AND CENTRAL
MOUNTAINS.
SNOW LEVELS ARE EXPECTED TO FALL AS THE FRONT PASSES ON WED...WITH
SNOW LOWERING INTO THE VALLEYS WED NIGHT. THE NORTH WILL REMAIN
FAVORED...WITH MOUNTAIN SNOW LIKELY WED-THU. AGREE WITH THE
PREVIOUS SHIFT THAT ACCUMULATIONS COULD RANGE FROM 3-6 INCHES
OVER THE NORTHWEST FACING SLOPES OF THE PARK...GORE...FLATTOPS AND
ELKHEAD RANGES.
MUCH COOLER DAYTIME TEMPERATURES EXPECTED ON WED ESPECIALLY OVER
THE NORTH...WITH ANOTHER BIG DROP ON THU. OVERNIGHT LOWS WED
NIGHT WILL ALSO BE UP TO 10 DEGREES COOLER THAN TONIGHT`S VALUES.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 418 AM MDT TUE OCT 23 2012
A TRAILING SHORTWAVE SWEEPS EASTWARD ACROSS THE REGION THURSDAY
NIGHT FINALLY CARRYING THE MAIN TROUGH AXIS EAST OF THE AREA BY
SUNRISE FRIDAY. EXPECT THIS FEATURE WILL SUSTAIN SNOW OVER THE
NORTHERN AND CENTRAL MOUNTAINS OVERNIGHT. AS BEFORE...MOISTURE NOT
LOOKING ALL THAT IMPRESSIVE AND AT THIS POINT IT APPEARS
ADDITIONAL ACCUMULATIONS WILL RANGE FROM 1 TO 3 INCHES. THE SOUTH
REMAINS MOISTURE STARVED SO WILL CONTINUE WITH LOW END POPS OVER
THE SAN JUANS WITH LESS THAN 10 PERCENT POPS ACROSS THE LOWER
ELEVATIONS.
MODELS INDICATED SHOWERS WILL DISSIPATE BY MIDDAY FRIDAY WITH A
RETURN TO DRY WEATHER UNDER NORTHWEST FLOW MOVING INTO THE
WEEKEND. GFS MAINTAINS A FAIRLY VIGOROUS NORTHWEST FLOW WITH A
SERIES OF WEAK DISTURBANCES BRUSHING THE NORTHERN COLORADO
MOUNTAINS BRINGING OCCASIONAL LIGHT SHOWERS SATURDAY THROUGH
MONDAY. IN CONTRAST...BOTH THE ECMWF AND THE GEM MODELS BUILD A
FLAT RIDGE OVER THE REGION AND NO PRECIPITATION. GIVEN MODEL
DIFFERENCES FEEL COMPELLED TO HOLD THE LINE WITH THE BLENDED MODEL
SOLUTION WHICH FEATURED SLIGHT CHANCES OVER THE NORTHERN MOUNTAINS
INTO EARLY NEXT WEEK.
THE INFLUX OF COLDER AIR BEHIND THE FRONT WILL BRING SOME OF THE
COLDEST TEMPERATURES EXPERIENCED SO FAR THIS FALL WITH HIGHS
RUNNING ABOUT 15 DEGREES BELOW NORMAL FRIDAY. OVERNIGHT LOWS
SATURDAY MORNING THREATEN TO BRING SEASON ENDING FREEZING
TEMPERATURES TO SOUTHEAST UTAH...THE GRAND VALLEY...AND THE LOWER
ELEVATIONS OF MONTEZUMA AND DOLORES COUNTIES IN SOUTHWEST
COLORADO. A WARMING TREND BEGINS SATURDAY AND WILL CONTINUE INTO
EARLY NEXT WEEK WITH HIGHS RETURNING TO NEAR NORMAL LEVELS BY
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1042 AM MDT TUE OCT 23 2012
MECHANICAL TURBULENCE AND LOW LEVEL WIND SHEAR WILL BE THE MAIN
AVIATION HAZARD TODAY. SOUTHWEST WIND WITH GUSTS IN THE 25-35KT
RANGE WILL BE COMMON. SURFACE WINDS ARE EXPECTED TO DIMINISH AFTER
01Z THIS EVENING AS COLD FRONT SEEPS INTO NORTHEAST UTAH AND
NORTHWEST COLORADO.
ISOLATED SHOWERS NEAR THE WYOMING BORDER WILL PARTIALLY OBSCURE
MOUNTAIN TOPS. ISOLATED THUNDERSTORMS MAY OCCUR AS WELL.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY UNTIL 7 PM MDT THIS EVENING FOR COZ001>003-007-008-
017-018.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...NL/EH
LONG TERM...NL
AVIATION...PF
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1211 PM CDT TUE OCT 23 2012
.DISCUSSION...
ISSUED 1036 AM CDT TUE OCT 23 2012
HAVE MADE TWEEKS TO TEMPS TODAY AND ADDED CHC POPS IN SOUTHEAST
FOR EARLY THIS AFTERNOON.
SHORTWAVE MOVING THROUGH AREA CURRENTLY IS ENHANCING PCPN
COVERAGE AND INTENSITY...PARTICULARLY SOUTHEAST HALF OF FORECAST
AREA. WAVE SHOULD MOVE PAST AREA EARLY THIS AFTERNOON AND
SHORTWAVE RIDGING SHOULD BUILD HEIGHTS AND ALLOW FOR SIGNIFICANT
SUBSIDENCE TO BRING AN END TO PCPN AND SOME BREAKS IN CLOUDS. THE
SLOWEST AREA OF IMPROVEMENT WILL LIKELY BE IN THE SOUTHEAST WHERE
REMNANT PCPN MAY LINGER AS AREA OF SHOWERS FORMED AT NOSE OF LOW-
LEVEL JET IN ERN MISSOURI MOVES EAST. ELSEWHERE...CAPPING SHOULD
INHIBIT ADDITIONAL DEVELOPMENT.
BREAKS IN CLOUDS SHOULD ALLOW TEMPS TO RESPOND. TEMPS ACROSS
SOUTHERN ILLINOIS ALREADY NEAR 70F AND WITH SOME SUN AND SOUTH
WINDS ADVECTING IN WARMER TEMPS...70S STILL LIKELY.
&&
.AVIATION...
ISSUED 1159 AM CDT TUE OCT 23 2012
SUBSIDENCE BEHIND SHORTWAVE MOVING THROUGH ILLINOIS AT PRESENT
SHOULD DIMINISH REMAINING PRECIP THIS AFTERNOON AND ALLOW FOR
ADDITIONAL BREAKS IN IFR CIGS. HOWEVER...ABUNDANT MOISTURE EVIDENT
IN MVFR OVERCAST TO WEST WILL LIKELY PUSH EAST OVERNIGHT IMPACTING
CENTRAL ILLINOIS TERMINALS. WILL BRING IN MVFR CIGS AND LINGER
UNTIL MIXING ALLOWS SOME LIFTING MIDMORNING WEDNESDAY.
WITH SOME PARTIAL CLEARING...SOUTH WINDS WILL LIKELY DEVELOP SOME
GUSTING LATE THIS AFTERNOON. SOME GUSTING WILL ONCE AGAIN DEVELOP
WITH LIFTING CIGS ON WEDNESDAY MORNING.
BARKER
&&
.PREV DISCUSSION...
ISSUED 310 AM CDT TUE OCT 23 2012
WARM FRONT CURRENTLY LOCATED OVER NORTHERN ILLINOIS...ROUGHLY
ALONG THE I-80 CORRIDOR. HAVE BEEN SEEING SHOWERS AND STORMS
INCREASING ACROSS WESTERN ILLINOIS AND ESPECIALLY OVER
MISSOURI...AS AN UPPER WAVE MOVES INTO THE AREA AND AN APPARENT
MESOSCALE VORTEX TRACKS ACROSS MISSOURI PER WATER VAPOR IMAGERY.
INITIAL FORECAST CONCERN INVOLVES CONVECTIVE TRENDS FOR PRIMARILY
THIS MORNING...ALONG WITH ITS EFFECTS ON TEMPERATURES. IN THE
LONGER RANGE...THE TIMING OF A STRONG COLD FRONT ON THURSDAY
REMAINS AN ISSUE...ALONG WITH RAIN TRENDS THURSDAY AND FRIDAY.
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
LATEST HRRR DOING A REASONABLE JOB WITH THE CONVECTION OVER
MISSOURI...AND IT CONTINUES TO INCREASE THE RAIN OVER MOST OF THE
CWA THROUGH EARLY MORNING. AS SUCH...HAVE RAMPED UP RAIN CHANCES
TO THE LIKELY RANGE IN MOST AREAS...PRIMARILY ALONG AND EAST OF
I-55. ANY LINGERING RAIN SHOULD BE TAPERING OFF EARLY IN THE
AFTERNOON. THE CONVECTION YESTERDAY REALLY THREW OFF THE HIGH
TEMPERATURE FORECAST...AND WILL HAVE TO KEEP THAT POTENTIAL IN
MIND FOR TODAY...ESPECIALLY IF CLOUDS ARE SLOW TO MOVE OUT. HAVE
LOWERED HIGHS FOR TODAY BY A FEW DEGREES IN MOST AREAS...CLOSER TO
A MET/MAV BLEND. HOWEVER...HAVE KEPT HIGHS NEAR 80 DEGREES ON
WEDNESDAY AND OVER THE EASTERN 2/3 OF THE CWA ON THURSDAY AS WELL.
UPPER WAVE CURRENTLY OVER THE PACIFIC NORTHWEST IS EXPECTED TO
FORM A CLOSED LOW AS IT MOVES NORTHEAST TO THE CANADIAN PRAIRIES
BY EARLY WEDNESDAY. 50-70 KNOT JET AT 500 MB WILL FOLLOW A WAVE
SLIDING ALONG THE SOUTHERN JET STREAM TO FEED INTO THE AREA AHEAD
OF THE COLD FRONT. LATEST MODEL GUIDANCE BRINGS THE FRONT INTO THE
NORTHWESTERN CWA THURSDAY AFTERNOON...AND ENTERING THE SOUTHEAST
CWA TOWARD MIDNIGHT. A NARROW WINDOW OF OPPORTUNITY EXISTS FOR
SOME STRONGER STORMS AHEAD OF THE FRONT THURSDAY AFTERNOON...
ALTHOUGH RAPIDLY INCREASING CLOUDS MAY THWART THIS POTENTIAL.
HOWEVER...THE RAIN WILL BE ON THE INCREASE...AND HAVE INTRODUCED
LIKELY POPS NORTHWEST OF THE ILLINOIS RIVER DURING THE AFTERNOON.
WITH THE BULK OF THE RAIN BEHIND THE FRONT...WILL SPREAD THE
LIKELY POPS FROM WEST TO EAST...WITH THE RAIN DIMINISHING WEST OF
I-55 AFTER MIDNIGHT.
LONG TERM...FRIDAY THROUGH MONDAY...
MODELS HAVE BEEN BACKING OFF ON THE IDEA OF A SECONDARY WAVE
FEEDING THE AREA BEHIND THE FRONT...WITH THE 00Z ECMWF THE ONLY
ONE STILL WITH THIS GENERAL TREND. WILL DROP THE RAIN CHANCES
NORTHWEST OF THE ILLINOIS RIVER ON FRIDAY AND FRIDAY NIGHT...AND
LOWER THEM QUITE A BIT FURTHER EAST. HOWEVER...THE GFS AND
CANADIAN MODELS WOULD SUGGEST COMPLETELY DRY CONDITIONS BY EARLY
FRIDAY EVENING EVERYWHERE...SO WILL NEED TO SEE IF THIS TREND
CONTINUES. HAVE REMOVED THE RAIN ON SATURDAY ASIDE FROM SOME
SLIGHT CHANCES EAST OF I-57...MAINLY DURING THE MORNING.
WEEKEND TREND STILL LOOKS QUITE CHILLY...WITH HIGHS IN MANY AREAS
STRUGGLING TO REACH THE 50 DEGREE MARK. SUB-FREEZING LOWS ARE
EXPECTED ALONG AND WEST OF I-55 BY SUNDAY MORNING. BEYOND
THAT...THE FORECAST TRENDS BECOME COMPLICATED BY A TROPICAL SYSTEM
MOVING NORTHWARD OFF THE EAST COAST. ECMWF MODEL IS MORE AFFECTED
AND FORMS A CUTOFF LOW OVER THE GREAT LAKES...LINGERING THE CHILLY
WEATHER INTO EARLY NEXT WEEK...WHEREAS THE GFS IS MORE PROGRESSIVE
AND MILDER. NEITHER SOLUTION CURRENTLY YIELDS ANY PRECIPITATION
FOR OUR AREA SUNDAY AND MONDAY.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1141 AM CDT TUE OCT 23 2012
.DISCUSSION...
858 AM CDT
UPDATED GRIDS AND ZFP HAVE BEEN SENT WITH SIGNIFICANT CHANGES TO
FIRST PERIOD.
MORNING WATER VAPOR IMAGERY SHOWS A WELL DEFINED SHORTWAVE TROUGH
MOVING EASTWARD OVER IA/MO. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS LIKELY TO CONTINUE TO PERCOLATE IN THE VERY MOIST
AIRMASS OUT AHEAD OF THIS SHORTWAVE. MAJORITY OF THE ASCENT WITH
THIS WAVE SHOULD BE EAST OF THE CWA BY LATE AFTERNOON WITH SHOWER
AND THUNDERSTORM COVERAGE EXPECTED TO DECREASE TOWARD EVENING.
HAVE BUMPED UP SKY COVER CONSIDERABLY TODAY WITH NO HOPE OF SEEING
ANY BREAKS IN THE OVERCAST UNTIL THIS SHORTWAVE PASSES EAST OF THE
AREA LATE THIS AFTERNOON. EVEN THEN ONCE THE MID/HIGH LEVEL
MOISTURE CLEARS OUT THINKING ITS VERY LIKELY STRATUS DECK WILL
STICK AROUND AS OUR LATE OCTOBER SUN ANGLE IS ROUGHLY THE SAME AS
EARLY FEBRUARY AND WITH SUCH LATE CLEARING OF HIGH CLOUDS AND VERY
MOIST LOW LEVELS THINK IT WILL BE TOO LITTLE TOO LATE FOR THE SUN
TO EAT AWAY AT THE STRATUS. IN FACT...THERE IS A VERY REAL CHANCE
THAT STRATUS COULD STICK AROUND TONIGHT INTO TOMORROW MORNING AS
WELL AND HAVE BUMPED UP SKY GRIDS SOME TONIGHT. AFTERNOON FORECAST
MAY NEED TO CONSIDER ADJUSTING SKY COVER UP FURTHER TONIGHT INTO
TOMORROW.
GIVEN THE ANTICIPATED THICK OVERCAST MOST OF TODAY HAVE TAKEN A
HATCHET TO THE GOING HIGH TEMPERATURE FORECAST. GENERALLY WOULD
EXPECT TEMPS TO REMAIN NEARLY STEADY MOST OF THE DAY IN THE LOW TO
MID 60S...WITH A COUPLE/FEW DEGREE TEMP RISE POSSIBLE LATE THIS
AFTERNOON...ESPECIALLY FAR WESTERN CWA WHICH COULD POSSIBLY MAKE
A RUN AT 70 DEGREES STILL.
IZZI
//PREV DISCUSSION...
326 AM CDT
EARLY THIS MORNING THE FRONTAL BOUNDARY HAS STALLED ACROSS THE IL/WI
STATELINE. TO THE NORTH OF THE BOUNDARY TEMPS HAVE HELD IN THE
MID/UPR 50S WITH DEW PTS IN THE LOW/MID 50S WITH AREAS OF DENSE FOG.
SOUTH OF THE BOUNDARY TEMPS HAVE REMAINED VERY MILD FOR MID OCTOBER
IN THE 60S...ALONG WITH ANOMALOUSLY HIGH DEW PTS OF AROUND 60. IR
IMAGERY EARLY THIS MORNING DEPICTED THE LEADING EDGE OF HIGH BASED
CLOUDS FLOATING NORTH ALONG A CENTRAL IOWA...NORTHERN IL...TO FAR
SOUTHWEST LOWER MICHIGAN LINE. THIS AREA OF HIGH CLOUDS AND VERY
MOIST AIRMASS WAS ASSOCIATED WITH AN ELEVATED SHORTWAVE LIFTING
NORTHEAST ACROSS SOUTHWEST MISSOURI. SHOWERS AND THUNDERSTORMS HAVE
BEEN STEADILY GROWING IN COVERAGE ACROSS MISSOURI...AND BASED ON
CURRENT TRAJECTORIES THE LEADING PRECIP SHOULD ARRIVE ALONG THE
SOUTHWEST CWFA AROUND DAYBREAK. THEN STEADILY LIFT NORTHEAST ACROSS
THE REMAINING CWFA BY MID-MORNING. CURRENT GUIDANCE INDICATES CAPE
OF AROUND 500-750J/KG IN THE 15-18 TIMEFRAME...WHICH APPEARS TO BE
THE HIGHEST CONFIDENCE TIMING FOR CONVECTION TO OCCUR. SO HAVE
CARRIED LIKELY SHRA/TSRA AT THAT TIME.
AS THE ELEVATED WAVE ARRIVES ACROSS THE CWFA THIS MORNING...IT WILL
REMAIN PROGRESSIVE AND ALLOW PRECIP TO DIMINISH IN COVERAGE FROM
SOUTH TO NORTH ACROSS THE CWFA THIS AFTN. SUPPORTING THIS DRYING
TREND WILL BE THE SLOW RISE IN HEIGHTS ALOFT...INDICATING WEAK
DIFFLUENCE ALOFT.
WITH REGARDS TO TEMPS TODAY...GUIDANCE IS DEMONSTRATING A HIGHER
CONFIDENCE THAT TEMPS WILL EASILY WARM INTO THE 70S. THE CHALLENGE
IS DETERMINE THE LOCATIONS THAT WILL WARM INTO THE MID 70S...WHICH
CURRENTLY APPEARS TO BE ALONG AND SOUTH OF A ROCKFORD TO KANKAKEE
LINE. THE OTHER WILDCARD FOR LOCATIONS NORTH OF THIS LINE WILL BE
THE CLOUD COVER AND LINGERING PRECIP. AT THIS TIME IT APPEARS BY 21Z
ALL BUT A FEW SHRA SHOULD HAVE DEPARTED THE CWFA TO THE
NORTH...ALTHOUGH CLOUDS MAY STILL BE MOSTLY CLOUDY. PWAT VALUES WILL
REMAIN ABOVE 1 INCH THRU THE DAY TDY...WITH A HANDFUL OF LOCATIONS
RISING TO NEARLY 1.5 INCHES. THE COMBINATION OF MILD TEMPS AND HIGH
MOISTURE CONTENT IN THE ATMOSPHERE WILL MAKE TODAY AND WED FEEL MORE
LIKE SUMMER.
SOUTHERLY FLOW WILL LINGER THROUGH THE OVERNIGHT...AND SHOULD BE
JUST STRONG ENOUGH TO PREVENT DENSE FG FROM FORMING. THUS WILL ONLY
MENTION PATCHY FG IN THE FORECAST TONIGHT. ANOTHER MILD NIGHT
APPEARS LIKELY FOR TONIGHT WITH TEMPS ONLY COOLING INTO THE LOW 60S.
A FEW GUIDANCE MEMBERS WERE WARMER THAN THIS IN THE MID 60S AT A
HANDFUL OF POINTS...HOWEVER FELT THE GENERAL CONSENSUS WOULD BE
AROUND 60 TO PSBLY LOW 60S. DRY WEATHER SHOULD LAST THROUGH THE
OVERNIGHT HOURS AS WELL.
WEDNESDAY THROUGH THURSDAY...
500MB RIDGE PUSHES OVERHEAD WITH WEAK DIFFLUENT FLOW IN THE
LLVLS...SUGGESTING MUCH OF WED THRU AT LEAST DAYBREAK THUR WILL
REMAIN DRY. FOR WED THIS WILL SET THE STAGE FOR A RUN AT TEMPS
AROUND 80...PSBLY WARMING INTO THE LOW 80S FOR A FEW LOCATIONS WED
AFTN. THE DEEPER MOISTURE WILL PEEL OFF TO THE NORTHEAST WITH THE
WARM FRONTAL BOUNDARY...WHICH MAY AID IN SLIGHTLY LOWER DEW PTS AND
PWAT VALUES HOVER AROUND 1 INCH WED AFTN. IF DEW PTS CAN FALL INTO
THE MID/UPR 50S...THIS WOULD ALLOW THE SFC TO WARM MORE EFFICIENTLY
AND ALLOW THE SFC TO EASILY REACH 80 DEG IN MANY LOCATIONS OF THE
CWFA. CURRENT TEMP PLUMES FROM THE SREF AND VARIOUS OTHER GUIDANCE
SOURCES...INDICATE TEMPS WED WILL BE IN THE MID/UPR 70S OVER THE FAR
NORTHERN TIER OF COUNTIES IN IL. MEANWHILE FURTHER SOUTH OR SOUTH OF
I-88...TEMPS COULD WARM INTO THE UPR 70S TO AROUND 80. CLOUDS WILL
ALSO PLAY A ROLE...HOWEVER CURRENTLY FORECASTING P-CLOUDY CONDS WED.
THEN FOR THUR AHEAD OF THE FRONTAL BNDRY...TEMPS COULD WARM AGAIN
INTO THE MID/UPR 70S MAINLY FOR FAR EASTERN SECTIONS OF THE CWFA.
500MB TROUGH AXIS WILL BEGIN TO PUSH INTO THE CENTRAL PLAINS WED
NGT/EARLY THUR...WITH THE MAIN VORT MAX ROUNDING THE TROUGH AXIS
EARLY THUR MORNING ACROSS THE SOUTHERN PLAINS. IT APPEARS THAT THE
DOWNSTREAM RIDGE WILL EXTEND FROM QUEBEC TO THE CAROLINAS...WHICH
MAY ALLOW THE FRONTAL BNDRY TO SLOW SLIGHTLY. IF THE BNDRY SLOWS
FURTHER...PRECIP COULD REMAIN WEST OF THE CWFA THRU THE EARLY AFTN
HOURS AND ALLOW TEMPS TO BE EVEN WARMER...GIVEN THE POTENTIAL FOR
COMPRESSIONAL HEATING TO OCCUR BETWEEN THE DEPARTING SFC RIDGE AND
UPSTREAM TROUGH.
INSTABILITY WILL DEVELOP WITH THE PASSAGE THUR AFTN...THEN SHUD
STABILIZE IN THE EVENING HOURS WITH FRONTAL PASSAGE. WINDS WILL TURN
NW...WITH MUCH COOLER AIR STEADILY ADVECTING ACROSS THE CWFA.
THERMAL RIDGE OF 15 TO 17 DEG C AT 850MB RAPIDLY TRANSITIONS TO
AROUND 5 DEG C BY 06Z FRI.
FRIDAY THROUGH MONDAY...
POTENT ANTI-CYCLONIC FLOW QUICKLY ARRIVES FRI...AND SHUD PUSH THE
PRECIP/CLOUDS TO THE EAST ACROSS IN/MI. HOWEVER A FEW EASTERN AREAS
COULD CONTINUE TO SEE A SLIGHT CHC POPS FRI. FRI APPEARS TO BE THE
WARMEST DAY IN THE FINAL PERIODS OF THE EXTENDED...WITH TEMPS
EXPECTED TO BE IN THE LOW 50S. THESE HIGH TEMPS MAY ACTUALLY ARRIVE
EARLY IN THE DAY...AS COLD AIR CONTINUES TO POUR IN FROM THE
NORTHWEST THROUGHOUT THE DAY.
LAKE EFFECT CONDS DEVELOP AND BECOME OPTIMAL FRI NGT/SAT/SAT NGT FOR
THE FAVORED AREAS OF NORTHWEST IN. THERMAL TROUGH OVERHEAD WILL
CONTINUE TO COOL WITH 0 TO -3 DEG C AT 850MB POISED TO PUSH OVERHEAD
SAT/SUN. THUS IT APPEARS TEMPS WILL STRUGGLE TO WARM BEYOND THE
LOW/MID 40S. AT THIS TIME IT DOES NOT APPEAR CLOUDS WILL BE A MAJOR
PLAYER. IN ADDITION DRY WEATHER SHOULD REMAIN THRU THE BULK OF THE
EXTENDED...WITH THE EXCEPTION OF NORTHWEST IN. ANY LINGERING PRECIP
DURING THE NOCTURNAL HOURS FRI/SAT/SUN COULD BECOME MIXED WITH SOME
WET SNOW...AS TEMPS WILL BE COOLING INTO THE MID 30S EACH OF THESE
NIGHTS. SAT NGT COULD BE THE COOLEST DAY AS GUIDANCE HAS INDICATED
THE SFC RIDGE PUSHING OVER CENTRAL WI. THIS COULD ALLOW WINDS TO
DIMINISH AND CLOUDS TO REMAIN MINIMAL...ALLOWING FOR OPTIMAL
RADIATIONAL COOLING TO TAKE PLAY SAT NGT. IF THIS SCENARIO WERE TO
VERIFY...TEMPS COULD EASILY BOTTOMOUT IN THE UPR 20S ACROSS THE
CWFA.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* IFR INTO EARLY AFTERNOON.
* WIND CONTINUING TO VEER FROM SE TO S AND SSW REST OF A.M. AND
EARLY THIS AFTERNOON.
* SCT -SHRA TIL EARLY-MID AFTERNOON. FEW SMALL TS IN AREA.
TRS
//DISCUSSION...UPDATED 16Z...
WARM FRONT HAS SLOWLY MOVED N DURING THE LATE MORNING AND HAD
REACHED ORD AT 16Z. WITH THE WIND VEERING TO SOUTHERLY VISIBILITY
AND CEILINGS HAVE IMPROVED. MDW GOT UP TO 020 THEN LOWERED BACK TO
014 AS A SHOWER JUST CLIPPED THE AIRFIELD. EXPECT CEILINGS THERE
TO RISE AGAIN WITHIN NEXT HR OR SO.
ADDITIONAL SHOWERS WITH A FEW HEAVIER SMALL CELLS HAVE BEEN MOVING
NE INTO N CENTRAL IL WITH EXTRAPOLATION OF RECENT MOVEMENT HAVING
THEM ARRIVE IN THE ORD AND MDW VC 17-18Z. NO ORGANIZATION IN THIS
ACTIVITY SEEN AND MAX TOPS REMAINING AOB 250 SO HAVE ONLY INCLUDED
MENTION OF VCSH AND NO TS IN TAFORS FOR THE AFTERNOON.
TRS
PREVIOUS DISCUSSION...UPDATED 14Z...
TROUGH/WARM FRONT HAS NOT LIFTED NORTHWARD AS SOON AS MODELS
EARLIER INDICATED AND EVEN LATEST AVAILABLE HI RES HRRR AND RAP
PLACE IT TOO FAR N NEAR/TO WI BORDER BY 15-16Z WHICH LOOKS TO BE
A COUPLE HRS TOO FAST. LIFR AND IFR EXPECTED TO PERSIST TIL
BOUNDARY DOES LIFT N PAST TERMINALS AND WINDS BECOME SOUTHERLY
BTWN 17Z-19Z THEN CIGS SHUD LIFT AND VSBYS IMPROVE.
BETWEEN AREA OF RA AND TS MOVING ENE OVER NRN IN AND ANOTHER AREA
OF MAINLY RA AND A FEW TS MOVING SLIGHTLY N OF E FM ERN MO ACROSS
THE MS RIVER ARE SCT DISORGANIZED -SHRA AND ISOLD SHRA. MODELS
SHOW BULK OF QPF E OF LOCAL TERMINALS BY 18Z AS UPPER TROUGH FROM
NRN MO SSE TO NORTHEASTERN AR MOVES OVER AND PAST THE LOCAL AREA.
MODELS DO INDICATE SPOTTY QPF 18Z-00Z BUT AMOUNTS OF ONLY A
COUPLE HUNDREDTHS OF AN INCH. DO NOT SEE ANY SIGNIFICANT FORCING
MECHANISMS FOR ADDITIONAL SHRA GENERATION BEYOND EARLY AFTERNOON.
TRS
PREVIOUS DISCUSSION...UPDATED 12Z...
TWO MAIN CONCERNS/CHALLENGES...CIGS AND TSRA THIS MORNING. LIFR
CIGS HAVE REMAINED LOCKED IN AND WITH CONTINUED LIGHT NORTHEAST
WINDS OFF THE LAKE...EXPECT AT LEAST A FEW MORE HOURS OF LIFR CIGS
UNTIL WINDS START TO TURN MORE SOUTHERLY AND CIGS LIFT. CONFIDENCE
REGARDING TIMING REMAINS LOW. ONCE CIGS DO LIFT...MVFR CIGS LIKELY
TO CONTINUE INTO THE EARLY/MID AFTERNOON.
ONE COMPLEX OF TSRA OVER EASTERN IL/WESTERN INDIANA WILL REMAIN
SOUTH OF THE TERMINALS WHILE CONVECTION OVER MISSOURI HAS WEAKENED
CONSIDERABLY IN THE PAST FEW HOURS. SHORT TERM GUIDANCE STILL
SUGGESTS FURTHER SHRA DEVELOPMENT ACROSS WESTERN IL THIS MORNING
BUT CONFIDENCE REGARDING TSRA POTENTIAL IS DECREASING AND TRENDS
WILL NEED TO BE MONITORED FOR POSSIBLE UPDATES.
SOUTHERLY WINDS MAY GUST INTO THE MID TEENS THIS AFTERNOON BUT
THIS WILL BE DEPENDENT ON SUNSHINE AND LOW LEVEL MIXING WHICH MAY
NOT OCCUR. SOUTHERLY WINDS WILL PERSIST TONIGHT AND SHOULD BEGIN
TO GUST SOME WEDNESDAY MORNING. WITH THE WARM FRONT EXPECTED TO BE
WELL NORTH OF THE AREA TONIGHT...NOT EXPECTING ANY WIDESPREAD FOG
OR LOW CIG PROBLEMS BUT HAVE INCLUDED SOME MVFR VIS AT RFD/DPA.
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE CIGS WILL LIFT TO ABV 020 BY EARLY AFTERNOON.
* MEDIUM CONFIDENCE THAT NO ADDITIONAL TS AT/VC TERMINALS THIS
AFTERNOON.
* HIGH CONFIDENCE WIND DIRECTION WILL REMAIN S-SSW.
* MEDIUM CONFIDENCE WINDS WILL BE IN 05-10 KT RANGE.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
* WEDNESDAY NIGHT...VFR.
* THURSDAY...STRONG/GUSTY SOUTHWEST WINDS. SHRA/TSRA THURSDAY
AFTERNOON/EARLY EVENING...ALONG/AHEAD OF WIND SHIFT/COLD FRONT.
* FRIDAY AND SATURDAY...SLIGHT CHANCE OF SHRA.
* SUNDAY AND MONDAY...VFR.
&&
.MARINE...
308 AM...A FRONTAL BOUNDARY HAS BECOME NEARLY STATIONARY JUST
SOUTH OF LAKE MICHIGAN EARLY THIS MORNING. IT WILL BEGIN TO SLOWLY
LIFT NORTH LATER TODAY AND TONIGHT AS LOW PRESSURE OVER THE
NORTHERN PLAINS LIFTS NORTH INTO SOUTHERN CANADA. HOWEVER...WITH
HIGH PRESSURE ACROSS ONTARIO...THE GRADIENT WILL REMAIN FAIRLY
STRONG ACROSS THE NORTHERN THIRD OR QUARTER OF THE LAKE WITH
EASTERLY WINDS 15-25 KTS INTO TONIGHT...SLOWLY TURNING SOUTHEAST
AND WEAKENING BY WEDNESDAY MORNING. NEW LOW PRESSURE WILL DEVELOP
OVER EASTERN COLORADO TONIGHT AND MOVE NORTHEAST TO NEAR LAKE
SUPERIOR BY THURSDAY AFTERNOON. THE GRADIENT WILL STEADILY TIGHTEN
AHEAD OF THIS FRONT WEDNESDAY NIGHT INTO THURSDAY MORNING BUT
FORECAST SOUNDINGS SHOW A FAIRLY STRONG MARINE LAYER/INVERSION.
BUT WINDS STILL EXPECTED TO REACH 30 KTS OR SO. WINDS WILL
DIMINISH AHEAD OF THE COLD FRONT LATE THURSDAY AFTERNOON/EARLY
THURSDAY EVENING THEN SHIFT OUT OF THE NORTHWEST BEHIND THE FRONT.
WITH HIGH PRESSURE BUILDING ACROSS THE PLAINS...THE GRADIENT
BEHIND THE FRONT WILL LIKELY SUPPORT GUSTS TO 30 KTS. COULD BE AN
HOUR OR TWO OF HIGHER GUSTS WITH/JUST BEHIND THE FRONT.
LIGHT WINDS ACROSS THE SOUTHERN TWO THIRDS OF THE LAKE...COMBINED
WITH THE VERY MOIST LOW LEVELS WILL LIKELY LEAD TO AREAS OF FOG
AND MAYBE SOME PATCHY DENSE FOG...THIS MORNING WHICH SHOULD
IMPROVE AS WINDS TURN MORE SOUTHERLY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-
LMZ673-LMZ675-LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878
UNTIL 10 AM WEDNESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
351 PM EDT TUE OCT 23 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
ONGOING PRECIP CHANCES THROUGH THIS EVENING AND CONTINUED MODERATING
TREND INTO WEDNESDAY WILL BE THE MAIN FORECAST ISSUES FOR THE SHORT
TERM.
CONVECTIVE COMPLEX AIDED BY MCV THIS MORNING HAS DIMINISHED...BUT
HAS LEFT SOME RESIDUAL COOL/STABLE LOW LEVELS. RAP INITIALIZATION
SOUNDINGS THIS AFTERNOON DO DEPICT SOME WEAK ELEVATED INSTABILITY
PERSISTING FOR 850 HPA BASED PARCELS HOWEVER. REMAINING SCATTERED
SHOWER ACTIVITY APPEARS TO BE FAIRLY WELL ALIGNED WITH WEAK DPVA
ZONE IN ADVANCE OF REMNANTS OF DAMPENING BAJA OF CALIFORNIA SHORT
WAVE. A STRONGER VORT MAX ASSOCIATED WITH THIS DECAYING TROUGH
APPEARS TO BE WORKING ACROSS SOUTHERN ILLINOIS THIS AFTERNOON AND
SHOULD REMAIN SOUTH OF FORECAST AREA. WILL CARRY SOME CHANCE POPS
LATE AFTERNOON INTO EARLY THIS EVENING IN ASSOCIATION WITH THE LEAD
SHORT WAVE...WITH PRECIP CHANCES DIMINISHING FROM WEST TO EAST THIS
EVENING. STILL CANNOT COMPLETELY RULE OUT AN ISOLD THUNDERSTORM
THROUGH 00Z GIVEN WEAK ELEVATED INSTABILITY AND PERIOD OF STRONGEST
FORCING WITH THIS SHORT WAVE. OTHERWISE...MILD CONDITIONS IN STORE
TONIGHT WITH LOCAL AREA REMAINING IN WARM SECTOR. SOME SCATTERING OF
LOW CLOUDS EXPECTED TONIGHT...AND RELATIVELY WEAK SFC GRADIENT
SHOULD ALLOW FOR MINS FROM THE MID TO UPPER 50S EAST...TO AROUND 60
FAR WEST. IF LOW CLOUDS DO SCATTER THIS EVENING...GRADIENT SHOULD
REMAIN WEAK ENOUGH FOR SOME PATCHY RADIATIONAL FOG TO DEVELOP BUT
STRENGTHENING LOW LEVEL HEIGHT GRADIENT LATE TONIGHT LENDS SOME LOW
CONFIDENCE IN THIS SCENARIO.
UNSEASONABLY WARM CONDITIONS IN STORE FOR TOMORROW AS REINFORCING
LOW LEVEL THERMAL RIDGE IN THE LEE OF THE ROCKIES ADVECTS NORTHEAST
INTO THE SOUTHERN GREAT LAKES. SOME LINGERING STRATUS IS POSSIBLE
MAINLY ACROSS FAR NORTH AND FAR EAST WEDNESDAY MORNING...BUT MOST
LOCATIONS SHOULD HAVE PLENTY OF AFTERNOON SUNSHINE. DESPITE LIMITED
MIXING HEIGHTS...MIXING TO 900 HPA SHOULD SUPPORT HIGHS IN THE UPPER
70S WHICH IS INLINE WITH PREVIOUS FORECAST. THE RECORD HIGH AT KSBN
FOR OCTOBER 24TH IS 79 SET BACK IN 1975 WHICH DOES APPEAR TO BE AT
RISK OF BEING REACHED. DRY...MILD CONDITIONS TO CONTINUE THROUGH
WEDNESDAY NIGHT AS AREA REMAINS IN WARM SECTOR. SOME DRIER LOW LEVEL
AIR WILL ADVECT NORTHWARD IN ADVANCE OF NEXT SIGNIFICANT UPPER
LEVEL TROUGH DIGGING ACROSS THE ROCKIES WHICH MAY TEND TO OFFSET THE
STRONGER GRADIENT WEDNESDAY NIGHT FOR LOWS SIMILAR TO THAT OF
TONIGHT.
&&
.LONG TERM.../THURSDAY THROUGH TUESDAY/
ENERGY FROM CLOSED LOW OFF THE WEST COAST WILL BEGIN TO TRANSLATE
EASTWARD WITH TIME AND BRING A CONTINUATION OF ACTIVE WEATHER AND
MUCH COOLER TEMPERATURES TO THE REGION.
THURSDAY THROUGH FRIDAY...
EFFECTS OF LARGE TROUGH DIGGING INTO THE PLAINS WILL FURTHER IMPACT
THE REGION WITH WARMEST AIR ARRIVING JUST AHEAD OF APPROACHING COLD
FRONT. MODEL SOUNDINGS SUGGEST MOSTLY SUNNY SKIES SHOULD ALLOW
MIXING THROUGH AT LEAST 900 MB AND POSSIBLY 850 MB YIELDING HIGHS
WELL INTO THE 70S WITH A FEW SPOTS RUNNING TOWARDS 80
POSSIBLE...ESPECIALLY SE. COLD FRONT WILL MOVE TOWARDS THE AREA BY
LATE AFTERNOON...INCREASING CLOUDS JUST AHEAD OF IT WITH EASTWARD
TREND EXPECTED IN TERMS OF MSTR THROUGH THURS NGT. MINOR DIFFERENCES
IN EXACT TIMING OF WIND SHIFT (GIVE OR TAKE A FEW HOURS) WITH ALL
MODELS GENERALLY AGREEING OF A SLOW PUSH AS WAVES MOVE ALONG THE
FRONT. AREA OF POST FRONTAL SHOWERS/STORMS ARE EXPECTED TO DEVELOP
TO THE WEST AND ENTER WESTERN AREAS DURING THE EVENING. COMBINATION
OF SOME DRY AIR ENTRAINMENT AND LESS OPTIMAL TIME FRAME FOR FROPA
MAY ALLOW FOR A DECREASE IN COVERAGE OF PRECIP INTO THE OVERNIGHT
HOURS. MODELS THEN REFIRE SHOWERS IN MAINLY EASTERN AREAS ON FRIDAY
AS MAIN ENERGY FINALLY DIGS IN AND PUSHES FRONT OUT OF THE AREA.
WITH INCREASED CLOUD COVER AND CAA UNDERWAY HIGHS ON FRIDAY WILL BE
A GOOD 15 TO 25 DEGREES COLDER THAN THURSDAY.
SATURDAY THROUGH TUESDAY...
CONFIDENCE IN FORECAST BEGINS TO WANE DURING THIS TIME FRAME WITH
MODEL CAMP GENERALLY SPLIT ON HANDLING ON INTERACTION BETWEEN
LONGWAVE TROUGH OVER THE GREAT LAKES AND TROPICAL CYCLONE SANDY OVER
THE WEEKEND INTO NEXT WEEK. INITIALLY...CONTINUED NW TO N FLOW OVER
THE LAKES WILL LIKELY KEEP LAKE EFFECT CLOUD COVER AND SOME CHANCES
FOR SHOWERS AROUND...POSSIBLY MIXED WITH SNOW. EXACT TRAJECTORIES
AND AMOUNT OF RESIDENT MSTR REMAIN IN QUESTION THIS FAR OUT.
GENERALLY WENT WITH COMBO OF PREV AND CONSALL TO HANDLE THIS TIME
FRAME.
RAN PRETTY MUCH WITH EITHER ALLBLEND OF GUIDANCE OR CONSALL FOR MANY
PARAMETERS INTO TUESDAY AS EXACT DETAILS OF EVOLUTION OF EAST COAST
SYSTEM REMAIN IN FLUX. ECMWF/GEM HAVE REMAINED CONSISTENT ON A
STRONG WESTWARD PULL OF THE TROPICAL SYSTEM INTO THE EASTERN STATES
VS GFS/GEFS SENDING IT OUT TO SEA. GIVEN THE PATTERN OF LATE NOD
GIVEN TO ECMWF/GEM...RESULTING IN ADDITION OF LOW END POPS TUESDAY
WHEN PROXIMITY OF ANY WRAP AROUND MSTR WOULD BE MOST FAVORABLE.
ALLBLEND RAN A BIT TOO HIGH SO WAS TEMPERED SOMEWHAT TO REMAIN
CONSERVATIVE.
&&
.AVIATION...
18Z TAFS...SEVERAL WEAK SHORT WAVES WILL CONTINUE TO ENHANCE
SHOWERS AND ISOLATED THUNDERSTORMS THROUGH MID AFTERNOON. AFTER
21Z...THE MORE PRONOUNCED OF THESE SHORT WAVES SHOULD BEGIN TO
SHIFT EAST OF THE TERMINALS...AND PRECIP COVERAGE IS EXPECTED TO
DIMINISH AFTER THIS TIME. HAVE MAINTAINED TEMPO MVFR CIGS AT KSBN
WHERE A PERIOD OF MORE SOLID RAIN SHOWERS IS EXPECTED THROUGH 20Z.
ANOTHER STRONGER SHORT WAVE NEAR STL SHOULD MAINTAIN A TRACK
PRIMARILY SOUTH OF THE TERMINALS...AND THUS WILL KEEP TAFS
TONIGHT. DESPITE SOME WEAK SFC BASED INSTABILITY EXPECTED AGAIN
FOR WEDNESDAY...BUILDING MID LEVEL HEIGHTS WILL RESULT IN DRY
CONDITIONS. SOME INCREASE IN SOUTH WINDS TOWARD THE END OF THE
PERIOD AS LOW LEVEL FLOW STRENGTHENS IN RESPONSE TO NEXT UPPER
LEVEL TROUGH DIGGING ACROSS THE ROCKIES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...MARSILI
LONG TERM...FISHER
AVIATION...MARSILI
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
449 PM EDT TUE OCT 23 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 447 PM EDT TUE OCT 23 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SW FLOW ALF OVER
THE CENTRAL CONUS BTWN DEEP TROF ALONG THE PACIFIC COAST AND UPR RDG
OVER ERN NAMERICA. THERE IS AN AREA OF SHRA/SOME TS OVER MAINLY THE
WRN CWA ASSOCIATED WITH A DISTURBANCE MOVING NEWD TO THE N OF H85
WARM FNT STRETCHING FM THE NRN PLAINS INTO THE UPR MIDWEST AND
ACCOMPANYING SHARPER H85-5 QVECTOR CNVGC/ISENTROPIC ASCENT BEST
SHOWN ON THE 300K SFC IN THE PRESENCE OF STEEP H85-5 LAPSE RATES
SHOWN ON THE 12Z MPX RAOB. SMALL HAIL FELL FM A FEW OF THE STRONGER
CELLS OVER THE WRN CWA/NW WI EARLIER. THE E HALF OF THE CWA HAS BEEN
MAINLY PCPN FREE WITH A DRIER/MORE STABLE PROFILE SHOWN ON THE 12Z
APX RAOB. EXCEPT FOR A CLUSTER OF SHRA/EMBEDDED TS OVER SCNTRL
WI...AREAS TO THE SW OF H85 WARM FNT ARE GENERALLY DRY WITH STRONG
CAP SHOWN ON THE 12Z ABERDEEN SDAKOTA RAOB DOMINATING. HOWEVER...
THERE IS QUITE A BIT OF LO CLD AND FOG WITH ABUNDANT LLVL MSTR/SFC
DEWPTS AN UNSEASONABLY HI 55 TO 60.
LATE THIS AFTN...AS AREA OF SHARPER ISENTROPIC ASCENT/DEEP LYR
QVECTOR CNVGC SUPPORTING THE NMRS SHRA/ISOLD TS OVER THE WRN CWA
EARLY THIS AFTN SHIFTS TO THE N...EXPECT DIMINISHING POPS S-N OVER
THE W. WITH ABSENCE OF UPR SUPPORT FOR PCPN OVER THE E HALF...
EXPECT ONLY ISOLD-SCT -SHRA IN THIS AREA. THE ONLY EXCEPTION MIGHT
BE THE SCNTRL...WHERE AREA OF SHRA NOW OVER WI AND DRIFTING TO THE
NE WILL BRUSH THE AREA.
TONIGHT...AS MAIN SHRTWV IN THE NRN PLAINS MOVG NEWD WELL TO THE W
LIFTS INTO SCNTRL CAN...UPR HGTS ARE FCST TO RISE SLOWLY OVER THE
CWA WITH AREA OF DEEP LYR QVECTOR CNVGC LIFTING TO THE N AND AWAY FM
UPR MI. WITH LACK OF DYANMIC SUPPORT AND FCST SDNGS HINTING AT MID
LVL DRYING/CAPPING AS SHOWN ON THE ABERDEEN RAOB...SUSPECT THERE WL
BE NOTHING MORE THAN ISOLD-SCT -SHRA WITH THE GREATER POPS THIS EVNG
OVER THE KEWEENAW INTO NCNTRL LK SUP. OTRW...INFLUX OF LLVL MSTR
WITH FLOW VEERING MORE TO THE S WL SUPPORT AREAS OF FOG...
ESPECIALLY OVER THE CNTRL CWA WITH UPSLOPE SE VEERING S FLOW. FOG IN
THIS AREA MIGHT BECOME DENSE. EXPECT LTL DIURNAL FALL OF TEMP WITH
INFLUX OF LLVL MSTR.
WED...COLD FNT ATTENDANT TO SHRTWV LIFTING TO THE NE THRU CNTRL
CANADA WL LIMP INTO THE WRN ZNS IN THE MRNG. SINCE THERE WL BE LTL
IN THE WAY OF LARGE SCALE FORCING AT THAT TIME...EXPECT NOTHING MORE
THAN SCT -SHRA TO ACCOMPANY ITS ARRIVAL. HOWEVER...APRCH OF MORE
SGNFT SHRTWV LIFTING OUT OF WRN TROF IN THE AFTN WL SUPPORT HIER
POPS THERE IN THE AFTN...WITH LOWER POPS TO THE E TOWARD HIER H5
HGTS AND AWAY FM INCOMING DEEP LYR QVECTOR CVNGC/FGEN/MSTR CNVGC
ALONG BNDRY. STEEP H7-5 LAPSE RATES SUPPORT MENTION OF TS. AREAS OF
FOG WL LIKELY PERSIST MUCH OF THE DAY UNDER CONSIDERABLE CLD
COVER...ESPECIALLY OVER THE CNTRL WITH PERSISTENT UPSLOPE LLVL FLOW.
ALTHOUGH TEMPS WL BE WELL ABV NORMAL...TENDED TO LOWER GOING FCST
MAX TEMPS A BIT TO ACCOUNT FOR EXPECTED FOG/CLD COVER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 447 PM EDT TUE OCT 23 2012
THE 500MB RIDGE WILL BE JUST TO OUR EAST /STRETCHING THROUGH THE
LOWER GREAT LAKES AND HUDSON BAY...WITH A WELL FORECASTED LOW
PUSHING IN FROM CENTRAL CANADA. SW FLOW ALOFT WILL REMAIN OVERHEAD
THROUGH SATURDAY NIGHT AS THE 500MB LOW SHIFTS FROM AROUND LAKE
WINNIPEG AT 00Z FRIDAY TO S HUDSON BAY FRIDAY...BEFORE EJECTING N
SATURDAY.
THE BEST CHANCE OF SHOWERS THROUGH THE ENTIRE EXTENDED LOOKS TO BE
WEDNESDAY NIGHT...THEN PUSHING W TO E DURING THE DAY THURSDAY AS THE
ELONGATED SFC LOW STRETCHING FROM THE KEWEENAW THROUGH N TX AT 06Z
THURSDAY DEEPENS SLIGHTLY AS IT PUSHES ACROSS LAKE SUPERIOR DURING
THE AFTERNOON HOURS...AND INTO NE ONTARIO BY 00Z FRIDAY. A FEW
THUNDERSTORMS WILL BE POSSIBLE MAINLY OVER THE W HALF WEDNESDAY
NIGHT...THEN CENTRAL AND E THURSDAY. THE SWATH OF HEAVIEST RAIN
/OVER AN INCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING/ LOOKS
TO HAVE SHIFTED SLIGHTLY WESTWARD. THIS INCLUDES AREAS FROM IWD
THROUGH CRYSTAL FALLS...AND N THROUGH THE KEWEENAW PENINSULA. THE
FAR EAST THIRD OF THE CWA MAY BE LUCKY TO RECEIVE HALF AN INCH BY
THE TIME IT IS DONE. A FEW SNOWFLAKES COULD MIX IN OVER INTERIOR W
LOCATIONS THURSDAY NIGHT AS COLD AIR WRAPS IN.
THE 23/00Z CANADIAN BRINGS A SECONDARY WAVE THAT LINGERED OVER LAKE
WINNIPEG AT 06Z FRIDAY...SLOWLY PUSHING IT TO JUST NW OF LAKE
SUPERIOR BY DAYBREAK SATURDAY...AND STILL JUST N OF THE LAKE SUNDAY
AFTERNOON. WHILE A TROUGH WILL LIKELY RESIDE NEAR LAKE SUPERIOR
THROUGH MUCH OF THIS TIME PERIOD...THE CANADIAN LOOKS TO BE A BIT
TOO STRONG/DEEP WITH THE FEATURE /AT LEAST A LITTLE TOO EARLY/. AS A
RESULT...WITH LEAN CLOSER TO THE ECMWF...AND UTILIZE A LITTLE LESS
OF THE CANADIAN OUTPUT FROM FRIDAY AFTERNOON ON.
THE 500MB TROUGH WILL LINGER OVERHEAD FROM SATURDAY THROUGH AT LEAST
SUNDAY NIGHT...AS A SFC HIGH PUSHES IN FROM THE W. BY SUNDAY NIGHT
THE GFS AND ECMWF SPLIT WAYS...ESPECIALLY WITH THE HANDLING OF THE
SYSTEM OFF THE EAST COAST. A MIX OF RAIN AND MOSTLY SNOW WILL BE
POSSIBLE SATURDAY...WITH ONSHORE ENHANCEMENT SATURDAY NIGHT OVER
THE KEWEENAW PENINSULA AS 850MB TEMPS COOL TO AROUND -9C. LOOKING AT
THE FCST MODELS CLOSER TO HOME THE GFS REMAINS MORE PROGRESSIVE...AS
AN ADDITIONAL 500MB LOW NEARS FROM S CENTRAL CANADA MONDAY NIGHT.
THE RESULT WOULD BE BRIEF RIDGING OVER THE UPPER GREAT LAKES MONDAY.
THE ECMWF ON THE OTHER HAND SINKS/WRAPS UP A LOW OVER THE OHIO
VALLEY. WILL NOT GET TOO SPECIFIC...BUT WILL LIMIT THE QUICKER
INFLUENCE OF THE NORTHERN LOW NEARING THE CWA ON DAY 6/7.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 128 PM EDT TUE OCT 23 2012
AS VEERING LLVL FLOW SHIFTING TO THE S ADVECTS MORE LLVL MSTR INTO
THE AREA...EXPECT IFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD.
DOWNSLOPE NATURE OF THE FLOW MAY LIMIT THE DROP IN CIG/VSBY AT
CMX/IWD AT TIMES THIS AFTN/TNGT...BUT WEAKENING WINDS WITH APRCH OF
LO PRES TROF LATER IN THE TAF PERIOD INDICATES LIFR CONDITIONS WL
PREDOMINATE AT THOSE SITES ON WED MRNG. AT SAW...THE SE-S WIND WL
UPSLOPE AND PRESENT A GREATER CHANCE FOR LIFR CONDITIONS. OTRW...
-SHRA WL IMPACT MAINLY CMX THIS AFTN...AND THERE COULD BE A TS THERE
AS WELL.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 PM EDT TUE OCT 23 2012
EXPECT E WINDS UP TO 30 KTS THIS EVENING...WITH A FEW GALE FORCE
GUSTS TO 35 KTS WHERE TERRAIN ENHANCES THESE WINDS OVER THE
NCENTRAL. ALTHOUGH THE STRONGER SE FLOW WILL PERSIST OVER THE E HALF
OVERNIGHT...THE WINDS WILL DIMINISH OVER THE W AFTER MIDNIGHT AS
SHARPER PRES GRADIENT SHIFTS TO THE NE IN ADVANCE OF AN APPROACHING
COLD FRONT. THIS WEAKER PRES GRADIENT WILL OVERSPREAD THE ENTIRE
LAKE ON WED...RESULTING IN DIMINISHING WINDS EVEN OVER THE E HALF.
SOME FOG IS LIKELY TO DEVELOP OVER THE W FOLLOWING THE COLD FROPA. A
NEW LOW WILL ORGANIZE ACROSS THE CENTRAL PLAINS WEDNESDAY AND LIFT
NORTHEASTWARD ACROSS LAKE SUPERIOR THURSDAY...WITH A FEW GALE FORCE
GUSTS OF 35KTS POSSIBLE OVER MAINLY CENTRAL LAKE SUPERIOR THURSDAY
NIGHT. A RIDGE OF HIGH PRESSURE WILL THEN BUILD INTO THE REGION
FRIDAY THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1251 PM CDT TUE OCT 23 2012
.SHORT TERM...
ISSUED AT 214 AM CDT TUE OCT 23 2012
(TODAY AND TONIGHT)
FOCUS WILL ONCE AGAIN BE TSRA CHANCES TODAY...TURNING TO TEMPS ONCE
PRECIP HAS ENDED.
ONGOING TSRA JUST W OF THE CWA IS ANTICIPATED TO CONTINUE TO MOVE
ENE THRU THE CWA TODAY. THE 23/04Z HRRR AND 23/00Z 4KM NCEP WRF ARE
IN GOOD AGREEMENT AND HANDLE THE ONGOING SITUATION RATHER WELL. PLAN
IS TO CLOSELY FOLLOW THESE MDLS FOR POPS TODAY...PROVIDED THIS TREND
CONTINUES. THESE MDLS...AS WELL AS THE OPERATIONAL MDLS...ARE IN
GOOD AGREEMENT WITH PRECIP ENDING BY EARLY AFTERNOON AT THE LATEST
AS THE S/W WILL BE NEARING THE IL/IN BOARDER BY 21Z.
WITH PRECIP COMING TO AN END AND CLOUDS CLEARING THRU THE
AFTERNOON...AMPLE INSOLATION SHUD BE AVAILABLE FOR A QUICK WARM UP
TODAY. MADE ONLY MINOR CHANGES TO THE GOING FORECAST FOR TEMPS TODAY
AND TONIGHT. RAISED TEMPS A COUPLE OF DEGREES ACROSS CNTL MO AS
850MB TEMPS SHUD BE NEARING 18C ACCORDING TO THE NAM. WHILE THIS IS
A WARM OUTLIER AMONG THE 00Z GUIDANCE...THIS SOLN SEEMS PROBABLE
GIVEN THE WARM 850MB TEMPS ADVECTING NEWD BEHIND THIS S/W. THAT
SAID...MDL SOUNDINGS FOR TODAY SUGGEST MUCH OF THE REGION WILL NOT
MIX TO 850MB AND HAVE THEREFORE TRENDED TWD THE WARMER
GUIDANCE...BUT REMAINED JUST UNDER ACROSS CNTL MO. SIMILAR TRENDS
CONTINUE TONIGHT WITH SLY TO SWLY WINDS WILL REMAIN AOA 7 KTS.
TILLY
&&
.LONG TERM...
ISSUED AT 349 AM CDT TUE OCT 23 2012
(WEDNESDAY THROUGH THURSDAY)
ONCE THE S/W RESPONSIBLE FOR THE ONGOING TSRA MOVES E OF THE
AREA...THE SHORT TERM IS EXPECTED TO REMAIN DRY UNTIL THURS. MDLS
ARE IN RELATIVELY GOOD AGREEMENT UNTIL WED NIGHT. THE GFS SUGGESTS A
REINFORCING S/W ROUNDING THE BASE OF THE UPPER LOW WHICH HELPS TO
SPEED UP FROPA THURS NIGHT. HAVE TRENDED TWD THE CONSENSUS OF THE
OTHER MDLS...BUT KEPT CHANCE POPS TO ACCOUNT FOR THE FASTER GFS
SOLN.
UNTIL THURS...FOCUS REMAINS TEMPS. NOT MUCH HAS CHANGED WITH THE
23/00Z GUIDANCE AND SAW NO REASON TO MAKE MANY CHANGES TO THE GOING
FORECAST. OVERALL...CONTINUED TREND GOING AOA WARMEST GUIDANCE.
(FRIDAY THROUGH MONDAY)
MDL TRENDS DO NOT CHANGE MUCH EARLY IN THE EXTD PERIOD. THE 22/18Z
DGEX DEVELOPS AN AMPLIFIED TROF WITH THE SYSTEM AFFECTING THE CWA AT
THE BEGINNING OF THE PERIOD AND CONTINUES TO DEEPEN THIS TROF THRU
THE WEEKEND. THIS SOLN IS AN OUTLIER AMONG THE OPERATIONAL
MDLS...EVEN AMONG THE GEFS...AND HAVE TRENDED TWD THE OTHER
OPERATIONAL MDLS THRU THE PERIOD.
THE GEM BEGINS TO SPEED UP TO COME INTO BETTER AGREEMENT WITH THE
GFS LATE FRI INTO SAT. HAVE THEREFORE TRENDED TWD THESE SOLNS
REGARDING POPS LOWERING POPS FRI NIGHT ACROSS NWRN PORTIONS OF THE
CWA AND KEPT SAT DRY. REMAINDER OF THE EXTD IS DRY FOR NOW...BUT
MDLS SUGGEST A COUPLE OF S/WS THAT MAY BRING PRECIP ACROSS NRN
PORTIONS OF THE CWA LATE IN THE EXTD PERIOD.
AS FOR TEMPS...MDLS ARE IN RELATIVELY GOOD AGREEMENT EARLY IN THE
PERIOD...LARGE DIFFERENCES BEGIN BY SUN AND PROVIDE A VARIETY OF
SOLNS THRU THE PERIOD. HAVE TRENDED TWD A COMPROMISE OF THE
GFS/ECMWF/GEM FOR FRI. WITH UNCERTAINTY GROWING THRU THE EXTD...HAVE
TRENDED TWD A BLEND OF THE GFS/ECMWF BEYOND FRI AS THESE SOLNS
REMAIN SOMEWHAT CLOSE.
TILLY
&&
.AVIATION...
ISSUED AT 1245 PM CDT TUE OCT 23 2012
MAIN AREA OF SHOWERS AND THUNDERSTORMS WEAKENING AND MOVING AWAY
FROM TAF SITES. SO MAIN ISSUE WILL BE THE CLOUDS THROUGH THE
FORECAST PERIOD. VFR/HIGH END MVFR CIGS TO SCATTER OUT THIS
AFTERNOON...WITH WINDS PICKING UP A BIT FROM THE SOUTH WITH GUSTS
TO NEAR 20 KTS AT TIMES. WINDS TO DIMINISH TOWARDS SUNSET...THEN
PICK BACK UP AGAIN BY MID MORNING ON WEDNESDAY AS WINDS MIX DOWN
TO SURFACE AND DIURNAL CU POP UP.
SPECIFICS FOR KSTL...MAIN AREA OF SHOWERS AND THUNDERSTORMS WEAKENING
AND MOVING AWAY FROM METRO AREA. SO MAIN ISSUE WILL BE THE CLOUDS
THROUGH THE FORECAST PERIOD. VFR CIGS TO SCATTER OUT THIS
AFTERNOON...WITH WINDS PICKING UP A BIT FROM THE SOUTH WITH GUSTS
TO NEAR 20 KTS AT TIMES. WINDS TO DIMINISH TOWARDS SUNSET...THEN
PICK BACK UP AGAIN BY MID MORNING ON WEDNESDAY AS WINDS MIX DOWN
TO SURFACE AND DIURNAL CU POP UP.
BYRD
&&
.CLIMATE...
ISSUED AT 319 PM CDT SUN OCT 21 2012
RECORD HIGHS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
OCTOBER 23 86(1939) 91(1939) 86(1939)
OCTOBER 24 85(1940) 86(1940) 84(1940)
RECORD HIGH MINIMUMS
DATE ST. LOUIS COLUMBIA QUINCY
----------------------------------------------
OCTOBER 23 67(2010) 65(1963) 63(1991)
OCTOBER 24 66(1991) 65(1991) 65(1991)
OCTOBER 25 69(1939) 68(1939) 63(1963)
MILLER
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
128 PM CDT TUE OCT 23 2012
.AVIATION...SKIES HAVE CLEARED AT BOTH THE KLBF AND KVTN TAF
SITES...AND SKIES SHOULD SLOWLY CLEAR EAST OF A LINE FROM KANW TO
KBBW THROUGH THE AFTERNOON. UNTIL SKIES CLEAR...WIDESPREAD IFR
CEILINGS WILL PREVAIL. A COLD FRONT WILL DROP INTO THE AREA
TONIGHT. A NARROW BAND OF MVFR/IFR CEILINGS MAY DEVELOP AFTER 09Z
BEHIND THE FRONT ACROSS CENTRAL AND SOUTHWEST NEBRASKA.
&&
.PREV DISCUSSION... /ISSUED 410 AM CDT TUE OCT 23 2012/
DISCUSSION...
PRIMARY FOCUS THROUGH THIS FORECAST PERIOD IS FOG AND TEMPERATURES
TODAY...THEN RAIN/SNOW CHANCES FOCUSED ON WEDNESDAY NIGHT AND
THURSDAY. BEYOND THAT...COLDER TEMPERATURES FOR THE LATTER HALF OF
THE WEEK.
WATER VAPOR IMAGERY THIS MORNING SHOWS A LONGWAVE TROUGH OVER THE
EASTERN PACIFIC INTO THE WESTERN CONUS...WITH RIDGING ACROSS THE
GREAT LAKES. A WEAK SHORTWAVE TROUGH WAS OBSERVED ACROSS THE
NORTHERN PLAINS...WITH SUBSIDENCE ALOFT ACROSS NEBRASKA HELPING TO
KEEP THE MID-LEVELS DRY THIS MORNING. SEVERAL OTHER SHORTWAVES OF
NOTE WITHIN THE LONGWAVE TROUGH WERE ONE OVER NEVADA...WITH
ANOTHER STILL OVER THE OCEAN. AT THE SURFACE...SOUTH TO SOUTHEAST
FLOW WAS BRINGING IN LOW LEVEL MOISTURE AND WITH THE DRY AIR
ALOFT...FOG HAS DEVELOPED ACROSS ALMOST ALL OF NEBRASKA BY 08Z.
THIS HAS KEPT TEMPERATURES UP...WITH READINGS IN THE MID 40S TO
LOW 50S. THE OTHER FEATURE TO NOTE IS LOW PRESSURE ON THE LEE SIDE
OF THE ROCKIES.
SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ACCORDING TO THE RUC AND THE NAM...FOG SHOULD SLOWLY DISSIPATE
FROM THE WEST...BUT PLACES OVER THE EASTERN PART OF THE FORECAST
AREA...EAST OF HIGHWAY 83 COULD SEE THE FOG LINGER INTO THE EARLY
AFTERNOON HOURS. THE FOG WILL HAVE A BIG IMPACT ON HIGH
TEMPERATURES TODAY SO IF IT FAILS TO DISSIPATE BY 18Z OR
19Z...TEMPERATURES COULD BE UP TO 10 DEGREES TO WARM IN PLACES.
DAY SHIFT WILL NEED TO MONITOR TRENDS IN CASE TEMPERATURE FORECAST
NEEDS TO BE MODIFIED. 850MB TEMPERATURES WILL INCREASE TODAY
/BETWEEN 15C AND 23C/ DUE TO WARM AIR ADVECTION AHEAD OF THE AREA
OF LOW PRESSURE TO THE WEST. ASSUMING SKIES CLEAR...TEMPERATURES
SHOULD WARM CONSIDERABLY...WITH LOW 80S POSSIBLE ACROSS SOUTHWEST
NEBRASKA. THE SHORTWAVE TROUGH OVER NEVADA WILL LIFT INTO MONTANA
TODAY...WHICH WILL GIVE THE FRONT TO THE WEST A BIT OF A PUSH
EASTWARD. THE NAM PUSHES A DRYLINE ACROSS THE SANDHILLS THIS
AFTERNOON...WHICH COULD DROP DEWPOINTS INTO THE LOW 30S. GOING
SOUTH...DEWPOINTS WILL DROP INTO THE 30S AS WELL AS THE DRYLINE
PROGRESSES EAST. THIS WILL PROMOTE DEEP MIXING TO NEAR 700MB.
WINDS THROUGH THE MIXED LAYER WILL BE STRONGEST ACROSS NORTHWEST
NEBRASKA...WHERE GUSTS TO 30 MPH LOOK POSSIBLE THIS AFTERNOON.
GOING SOUTH...WINDS ALOFT DECREASE SO WINDY CONDITIONS ARE NOT
EXPECTED. WITH THE TEMPERATURES EXPECTED TODAY...LOWEST RELATIVE
HUMIDITY WILL BE ACROSS SOUTHWEST NEBRASKA...WITH VALUES DROPPING
TO THE MID 20S WHERE WINDS WILL BE STRONG. AS IS
FORECAST...CRITICAL FIRE WEATHER CONDITIONS WILL NOT BE
MET...ALTHOUGH MARGINAL CONDITIONS WILL BE LIKELY IN A FEW
LOCATIONS FOR AT LEAST A FEW HOURS TODAY. AGAIN...CLOUD COVER
COULD HAMPER THIS FROM OCCURRING...SO WILL NEED TO MONITOR TRENDS
FOR POTENTIAL FIRE WEATHER ISSUES TODAY.
THE MONTANA WAVE LIFTS INTO CANADA TONIGHT...WITH A COLD FRONT TO
THE WEST PROGRESSING SOUTHEAST ACROSS NEBRASKA TONIGHT. BY MID
MORNING WEDNESDAY SHOULD BE THROUGH MOST OF THE FORECAST AREA.
COULD AGAIN SEE SOME FOG WEDNESDAY MORNING...BUT THIS SHOULD BE
CONFINED TO AREAS RIGHT ALONG AND BEHIND THE FRONT WHERE LOW LEVEL
MOISTURE POOLS. A THE SHORTWAVE TROUGH WILL ALSO MOVE ONLAND
TONIGHT...WHICH WILL THEN PROGRESS ACROSS UTAH AND INTO COLORADO
ON WEDNESDAY. AS THIS IS ONGOING...A 700MB TROUGH WILL PASS ACROSS
THE NORTHERN AND CENTRAL PLAINS WEDNESDAY AND WEDNESDAY NIGHT.
MODELS ARE SHOWING GOOD FRONTOGENETICAL FORCING...WHILE THE
LOCATION OF THE UPPER LEVEL JET STREAK PUTS NORTHWEST NEBRASKA IN
AN AREA OF GOOD LARGE-SCALE LIFT. THE SIGNAL HAS BEEN QUITE
CONSISTENT IN TIMING AND LOCATION OF THE BEST FORCING FROM THE
DIFFERENT MODELS OVER THE PAST FEW DAYS SO CONFIDENCE HAS
INCREASED IN GETTING PRECIPITATION ACROSS THE FORECAST AREA. IT
MAY TAKE A BIT OF TIME TO SATURATE THE LOW LEVELS...SO ONLY BEGAN
CHANCES FOR RAIN IN THE FAR NORTHERN PARTS OF SHERIDAN AND CHERRY
COUNTIES WEDNESDAY MORNING AND SLOWLY EXPANDING SOUTH THROUGH THE
AFTERNOON. WEDNESDAY EVENING LOOKS TO SEE THE BEST CHANCES FOR
PRECIPITATION IN AREAS NORTHWEST OF AN IMPERIAL TO VALENTINE
LINE...AND THOUGH DO HAVE RAIN CHANCES TO THE EAST...LOWERED
CHANCES BEFORE MIDNIGHT AS TOO MUCH DRY AIR LOOKS TO EXIST IN
THESE AREAS. THE PRECIPITATION AREA DOES SHIFT TO THE SOUTH AND
EAST AFTER MIDNIGHT...BUT AS THE PRIMARY SHORTWAVE TROUGH EXITS
THE AREA BY 12Z THURSDAY MORNING...LARGE-SCALE FORCING WILL
DETERIORATE SO CHANCES HAVE LOWERED FOR THURSDAY. BY LATE
AFTERNOON THURSDAY...EXPECT THE FORECAST AREA TO SEE PRIMARILY DRY
CONDITIONS. THERE IS ANOTHER SHORTWAVE THAT WILL ROUND THE
LONGWAVE TROUGH LATER THURSDAY AND THURSDAY NIGHT...BUT THE TREND
CONTINUES TO GO SOUTH SO PRECIPITATION CHANCES LOOK TO STAY TO THE
SOUTH. TEMPERATURE PROFILES CONTINUE TO SHOW THE PRECIPITATION
TYPE BEGIN AS RAIN...BUT CHANGE OVER TO A RAIN/SNOW MIX WITH SNOW
BECOMING THE DOMINANT TYPE ACROSS THE NORTHWEST AREAS AFTER
MIDNIGHT WEDNESDAY NIGHT. HAVE RAIN OR SNOW IN THE FORECAST ACROSS
THE ENTIRE AREA FOR THURSDAY MORNING AS THE PROFILES HUG 0C IN THE
LOWEST LEVELS ABOVE THE SURFACE. DON/T EXPECT MUCH ACCUMULATION OF
SNOW...WITH PRECIPITATION ACCUMULATIONS UP TO A THIRD OF AN INCH
MAINLY NORTH OF INTERSTATE 80.
LONG TERM...FRIDAY THROUGH MONDAY
COLD TEMPERATURES WILL BE THE HIGHLIGHT FOR THE WEEKEND AS HIGHS
WILL BE HARD PRESSED TO MAKE IT OUT OF THE 30S AND 40S FOR FRIDAY
AND SATURDAY. LOWS ALSO WILL BE QUITE COLD...ALTHOUGH THE 23.00Z
MODEL SOLUTIONS ARE A BIT WARMER FOR BOTH FRIDAY AND SATURDAY
NIGHTS WITH THE SURFACE HIGH NOW LOOKING TO STAY OFF TO THE EAST
OF THE FORECAST AREA. LOWS SHOULD STILL EASILY DROP INTO THE
20S...WITH TEENS POSSIBLE FRIDAY NIGHT.
THE TREND NOW LOOKS FOR WARMER CONDITIONS GOING INTO NEXT WEEK AS
RIDGING BUILDS OVER THE WESTERN HALF OF THE COUNTRY. THIS WILL
BRING MILD TEMPERATURES BACK INTO THE CENTRAL PLAINS WITH 850MB
TEMPERATURES WARMING INTO THE TEENS AGAIN BY MONDAY...COMPARED TO
READINGS BELOW 0C WHICH WILL BE EXPERIENCED FRIDAY AND SATURDAY.
THE FORECAST IS DRY THROUGH THIS PERIOD AS THE LONGWAVE TROUGH
WILL PUSH THE MOISTURE ACROSS THE PLAINS WELL TO THE
SOUTHEAST.
AVIATION...
LIFR/IFR CIGS AND VSBY IMPROVE TO VFR FROM WEST TO EAST BETWEEN 15Z
AND 18Z ALONG AND WEST OF HIGHWAY 83. EAST OF HIGHWAY 83...LIFR/IFR
CIGS AND VIS IMPROVE TO IFR/MVFR CIGS AROUND 18Z AND THEN VFR BY 21Z.
A COLD FRONT WILL DROP INTO THE FCST AREA TONIGHT WITH MVFR/IFR CIGS
POSSIBLE AFTER 06Z TUESDAY NIGHT.
FIRE WEATHER...
POTENTIAL RED FLAG CONDITIONS WILL BE MONITORED ACROSS WRN NEB THIS
AFTERNOON DEPENDING ON THE PROGRESS OF A CLEARING LINE FCST TO
DEVELOP ACROSS THE PANHANDLE THIS MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...WFO LBF
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1236 PM CDT TUE OCT 23 2012
.AVIATION...18 KGRI TAF. PREVAILING LIFR CONDITIONS FORECAST
THROUGH 20Z...WITH VFR CONDITIONS EVENTUALLY RESTORED BY
22Z...FOLLOWED BY ANOTHER ROUND OF LIFR CONDITIONS WEDNESDAY
MORNING. STRATUS PERSISTS ACROSS MUCH OF THE REGION AT THIS
HOUR...HOWEVER SATELLITE IMAGERY INDICATES CLEARING TO THE
SOUTHEAST AND THE NORTHWEST OF THE TERMINAL. UNFORTUNATELY KGRI
WILL BE ONE OF THE LAST LOCATIONS TO EXPERIENCE CLEARING
TODAY...BUT EVEN THEN CLOUDS ARE EXPECTED TO SCATTER OUT BY 22Z.
VFR CONDITIONS SHOULD PERSIST THROUGH MUCH OF TONIGHT...WITH THE
REDEVELOPMENT OF STRATUS PROMOTING LIFR CONDITIONS AT THE TERMINAL
BY 11Z WEDNESDAY. VISIBILITY RESTRICTIONS IN FOG AND/OR DRIZZLE
WILL REMAIN POSSIBLE AT THE TERMINAL THROUGH 20Z TODAY...AND AGAIN
11Z AND BEYOND ON WEDNESDAY. THE SURFACE WIND WILL REMAIN
GENERALLY LIGHT AND VARIABLE THROUGH THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1111 AM CDT TUE OCT 23 2012/
UPDATE...MORNING UPPER AIR ANALYSIS INDICATES LONG WAVE TROUGHING
OVER THE WESTERN HALF OF THE CONUS AND RIDGING OVER THE EAST. MID
AND UPPER LEVEL JET ENERGY EXTENDS FROM CALIFORNIA...NORTHEAST
ACROSS THE ROCKY MOUNTAIN RANGE INTO THE NORTHERN PLAINS...THEN
INTO SOUTH CENTRAL CANADA AND THEN EAST/SOUTHEAST INTO
SOUTHEASTERN CANADA AND THE NORTHEASTERN CONUS. TROPOSPHERIC FLOW
OVER THE CENTRAL PLAINS IS NOT PARTICULARLY STRONG AS A
RESULT...WITH THE WIND PEAKING OUT AT AROUND 70KTS NEAR 200MB.
WATER VAPOR IMAGERY INDICATES INCREASED VALUES OF MID LEVEL
MOISTURE EXTENDING ALONG THE JET AXIS FROM THE WESTERN CONUS INTO
SOUTH CENTRAL CANADA...HOWEVER MUCH OF THIS MID LEVEL MOISTURE
REMAINS NORTHWEST OF OUR AREA. AT THE SURFACE A STATIONARY FRONT
IS NOTED EXTENDING FROM SOUTHWESTERN IOWA...SOUTHWEST TO NEAR
KCNK...KGBD AND KDDC. THE LOW LEVEL WIND FIELD ACROSS OUR CWA
REMAINS FAIRLY LIGHT THIS MORNING...HOWEVER THE PREDOMINANT WIND
DIRECTION REMAINS FROM THE EAST/NORTHEAST DUE TO THE LOW LEVEL
BAROCLINIC ZONE TO OUR SOUTHEAST. ISENTROPIC UPGLIDE AND
SATURATION ACROSS THE LOW LEVEL BAROCLINIC ZONE...PRIMARILY ALONG
THE 290-295K SURFACES...CONTINUES TO PROMOTE WIDESPREAD STRATUS
ACROSS THE REGION THIS MORNING...WITH CEILINGS HOLDING GENERALLY
IN THE 100-300FT AGL RANGE ACROSS OUR AREA. IN ADDITION TO THIS
STRATUS...LOW LEVEL MOISTURE FLUX INTO THE AREA IS ALSO WORKING TO
PROMOTE CONTINUED FOG ACROSS MUCH OF THE AREA...WITH ENOUGH LOW
LEVEL TURBULENT MIXING FOR DRIZZLE AS WELL...PRIMARILY ACROSS OUR
EASTERN CWA. AS OF 1530Z THE LOWEST VISIBILITIES EXIST ALONG A
LINE FROM KAUH...TO KGRI...TO KEAR...TO KHDE AND KPHG...WHICH IS
WHERE VISIBILITY RESTRICTIONS OF 1/4SM TO 1/2SM ARE IN EXISTENCE.
TO THE NORTHWEST AND SOUTHEAST OF THIS LINE...VISIBILITY
RESTRICTIONS OF AROUND 1SM ARE BEING OBSERVED.
IMPROVEMENTS IN VISIBILITY HAVE BEEN NOTED ACROSS MUCH OF THE CWA
THROUGH PAST FEW HOURS WITH MOST LOCATIONS ACROSS OUR CWA NOW
ABOVE 1/4SM. AS A RESULT...THE DENSE FOG ADVISORY WAS LET GO AT
15Z. THAT BEING SAID...FOG...WITH VISIBILITY RESTRICTIONS
GENERALLY BETWEEN 1/2SM AND 1SM...STILL PERSISTS ACROSS THE AREA
AND WILL LIKELY BE OBSERVED THROUGH AT LEAST MIDDAY. BIGGEST
QUESTION FOR THE REST OF TODAY IS WHETHER OR NOT ENOUGH DIABATIC
HEATING WILL BE REALIZED FOR COMPLETE FOG DISSIPATION. THE CURRENT
HOPE IS THAT THE LOW LEVEL BAROCLINIC ZONE...CURRENTLY TO OUR
SOUTHEAST...WILL MAKE ENOUGH PROGRESS NORTH/NORTHWEST ACROSS OUR
AREA...THUS PUSHING THE BEST ISENTROPIC UPGLIDE TO OUR NORTH AND
CARRYING THE CLOUD COVER WITH IT. WITH CLOUD COVER DIMINISHING
OVER MUCH OF OUR AREA AND INCREASING DIABATIC HEATING...ENOUGH OF
A LOW LEVEL DEWPOINT DEPRESSION SHOULD PRESENT ITSELF FOR COMPLETE
FOG DISSIPATION AND SUNNIER SKIES THIS AFTERNOON. IF HOWEVER THE
LOW LEVEL BAROCLINIC ZONE DOES NOT MAKE AS MUCH PROGRESS
NORTH/NORTHWEST AS CURRENTLY EXPECTED...THEN THIS AFTERNOON COULD
TURN OUT BEING MUCH CLOUDIER THAN FORECAST...WITH FOG POTENTIALLY
PERSISTING THROUGH MUCH OF THE DAY. WITH CURRENT SHORT TERM
GUIDANCE SUGGESTING SUNNIER SKIES ACROSS MOST ALL OF THE CWA THIS
AFTERNOON...WILL STAY THE COURSE AND CONTINUE PRESENT PARTLY
CLOUDY SKIES WITH HIGHS IN THE 60S AND 70S FOR THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 516 AM CDT TUE OCT 23 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. ANOTHER NIGHT...AND ANOTHER
SET OF SEVERAL TRICKY FORECAST ELEMENTS DURING THE NEXT 72
HOURS...NAMELY HIGH TEMPS AND PRECIP/FOG TRENDS...AND WHETHER ANY
STORMS WED NIGHT MIGHT GO SEVERE.
09Z OBJECTIVE SURFACE ANALYSIS CONFIRMS THAT THE ENTIRE CWA LIES
NORTH OF A QUASI-STATIONARY BOUNDARY SNAKING EAST-NORTHEAST ACROSS
SOUTHERN/EASTERN KANSAS AND EXTENDING FROM A WEAK 1003MB LOW IN
SOUTHEAST CO. BREEZES ACROSS THE CWA RANGE FROM LIGHT/VARIABLE TO
LIGHT EASTERLY...WITH LITTLE IF ANY TEMP/DEWPOINT DEPRESSION WITH
VALUES RANGING GENERALLY 47-53 ALL AREAS. AS EXPECTED 24 HOURS
AGO...VARYING DEGREES OF FOG HAVE SETTLED IN OVERNIGHT...WITH THE
ENTIRE CWA SEEING NO BETTER THAN 2-3 MILE VISIBILITY...AND THE MOST
CONCENTRATED ZONE OF DENSE FOG 1/4 MILE OR LOWER VSBY FOCUSED FROM
I-80 SOUTHWARD INTO KANSAS PER AUTOMATED OBS AND WEBCAMS. LIGHT
DRIZZLE HAS SEEMINGLY BEEN OFF AND ON OVERNIGHT...BUT IS LIKELY
STILL PRESENT IN MUCH OF THE CWA. ALOFT...WATER VAPOR SATELLITE
IMAGERY AND LATEST MODEL DATA CONFIRM BROAD WEST- SOUTHWEST FLOW
OVER THE CENTRAL PLAINS...WHICH IS POSITIONED DOWNSTREAM FROM A
LARGE SCALE TROUGH ANCHORED ACROSS THE PACIFIC NORTHWEST WITH A
CLOSED 500MB LOW OFF THE WASHINGTON STATE COAST. CLOSER TO
HOME...A SMALL SCALE SHORTWAVE TROUGH IS CURRENTLY DEPARTING
EASTWARD ACROSS MO...PROMOTING CONSIDERABLE ELEVATED THUNDERSTORM
ACTIVITY IN THAT AREA.
STARTING OFF EARLY THIS MORNING...THE MOST IMMEDIATE ISSUE IS THE
ONGOING CWA-WIDE DENSE FOG ADVISORY VALID THROUGH 15Z...AND WILL
LET IT RIDE AS-IS FOR NOW. TECHNICALLY SPEAKING...AUTOMATED OBS
SUGGEST THAT SO FAR THE MAJORITY OF ANY LOCALLY DENSE FOG HAS BEEN
CONFINED TO AREAS SOUTH OF THE I-80 CORRIDOR...BUT VARIOUS SHORT
TERM VISIBILITY GUIDANCE FROM THE HRRR/SREF SUGGEST THAT A
NORTHWARD EXPANSION OF DENSE FOG IS QUITE POSSIBLE YET THIS
MORNING...AND AM NOT ABOUT TO CANCEL ANY OF THIS ADVISORY UNTIL
TRENDS CAN BE MONITORED FOR AT LEAST A FEW MORE HOURS. IN
FACT...AM STARTING TO EVEN WONDER IF THE 15Z EXPIRATION TIME WILL
BE LONG ENOUGH...WITH BOTH THE HRRR AND HOURLY GFS LAMP GUIDANCE
SUGGESTING THAT SOME AREAS COULD REMAIN RATHER SOCKED IN UNTIL AT
LEAST 16Z-17Z. DAY SHIFT WILL HAVE TO KEEP AN EYE ON THE POSSIBLE
NEED FOR AN EXTENSION. AS FOR THE OFF AND ON LIGHT DRIZZLE SUCH AS
OBSERVED HERE AT THE WFO TONIGHT...HAVE IT MENTIONED CWA-WIDE
THROUGH 12Z...BUT HAVE THEN ATTEMPTED TO CONFINE IT TO ONLY A
HANDFUL OF COUNTIES EAST OF HWY 281 POST-SUNRISE...WHERE NAM
SOUNDINGS INDICATED THAT THE SATURATED LAYER WOULD REMAIN
DEEPER...GENERALLY NEAR/IN EXCESS OF 2500 FT. THAT BEING
SAID...CANNOT COMPLETELY RULE OUT POST-SUNRISE LIGHT DRIZZLE EVEN
IN THE TRI-CITIES AREA WESTWARD GIVEN SUCH A MOIST LOW LEVEL
PROFILE. AS FOR SKY COVER...CONFIDENCE IS CONSIDERABLY HIGHER
TODAY THAT MUCH OF THE CWA WILL SEE AT LEAST A FEW HOURS OF PARTLY
TO MOSTLY SUNNY SKIES AT SOME POINT...BUT EXACTLY WHEN IS STILL
IN QUESTION. HAVE GENERALLY FOLLOWED THE 00Z/06Z NAM SOLUTION OF
KEEPING NEARLY ALL AREAS SOCKED IN WITH STRATUS AND AT LEAST LIGHT
FOG THROUGH THE MORNING HOURS...BUT THEN ERODING FROM WEST-EAST
THROUGH THE AFTERNOON WEARS ON AS EVIDENCED BY THE 900MB RELATIVE
HUMIDITY FIELD. THIS MEANS THAT FAR EASTERN COUNTIES ALONG THE HWY
81 WOULD BE LAST TO SEE ANY CLEARING. AFTER BUSTING HIGH TEMPS BY
10+ DEGREES YESTERDAY DUE TO WIDESPREAD LOW STRATUS...AM IN NO
HURRY TO GO WITH THE WARM END OF AVAILABLE GUIDANCE/MODEL
SOLUTIONS TODAY ESPECIALLY IN EASTERN ZONES. AFTER TRYING VARIOUS
SOLUTIONS ON FOR SIZE...ENDED UP GOING WITH THE 00Z NAM ALMOST
EXACTLY...AS ITS TEMP FIELD SEEMED TO BEST-CAPTURE THE GRADUAL
WEST-EAST CLEARING. THIS RESULTS IN A DECENT RANGE FROM NEAR 80
FAR WEST ...LOW-MID 70S CENTRAL AND UPPER 60S EAST. PLEASE NOTE
THESE VALUES ARE AT LEAST A FEW DEGREES COOLER THAN PREVIOUS
FORECAST ALL AREAS...AND AS MUCH AS 5-8 DEGREES COOLER IN THE
EAST. LIKE YESTERDAY...COULD EASILY FORESEE HIGHS BEING OFF BY 5+
DEGREES DEPENDING ON STRATUS/FOG TRENDS.
TONIGHT...KEPT OUT ALL MENTION OF PRECIP CWA-WIDE...AND AM NOT
EXPECTING A DENSE FOG REPEAT SUCH AS THE ONGOING ONE...BUT DID
INSERT A PATCHY FOG MENTION INTO SEVERAL COUNTIES NORTH OF I-80
AFTER MIDNIGHT IN CLOSEST PROXIMITY TO THE HIGHEST BOUNDARY LAYER
RELATIVE HUMIDITY POOLING IN THE VICINITY OF THE LEADING EDGES OF
THE INVADING COLD FRONT. CLOUD TRENDS TONIGHT ARE CERTAINLY A
CHALLENGE...WITH THE POTENTIAL FOR QUITE AN INCREASE IN STRATUS
TOWARD SUNRISE NEAR THIS BOUNDARY...FOLLOWING WHAT SHOULD BE A
FAIRLY CLEAR EVENING FOR MOST AREAS. ALOFT...THE BIG PICTURE
INVOLVES A LEAD SHORTWAVE TRACKING ACROSS FAR SOUTH CENTRAL
CANADA...WHICH HELPS DRIVE THE SURFACE FRONT INTO THE NORTHERN
CWA...WHILE A TROUGH AXIS SETS UP FROM SOUTHWEST-NORTHEAST ACROSS
KS. KEPT LOWS SIMILAR TO PREVIOUS FORECAST AND A GUIDANCE
BLEND...RANGING FROM LOW-MID 40S NORTHWEST TO UPPER 50S/NEAR 60
SOUTHEAST WHERE DEWPOINTS WILL BE ON THE INCREASE.
WEDNESDAY...OTHER THAN THE LINGERING PATCHY FOG MENTION NORTH IN
THE MORNING...HAVE KEPT OUT ANY OTHER WEATHER MENTION THROUGH
SUNSET...AS THE GENERAL MODEL CONSENSUS IS TO KEEP ANY LIGHT
DAYTIME DRIZZLY PRECIP NORTHEAST OF THE CWA...AND ANY LATE-DAY
CONVECTION ALONG/NEAR THE INVADING COLD FRONT JUST SOUTHEAST OF
THE CWA. THAT BEING SAID...SKY COVER AND TEMP TRENDS ARE AGAIN
QUITE A CHALLENGE...AS QUITE A BIT OF STRATUS SHOULD DOMINATE MUCH
OF THE NORTHWEST CWA WITH MORE SUNSHINE SOUTHEAST.
FORTUNATELY...THE LATEST MODEL RUNS ARE IN REASONABLY GOOD
AGREEMENT REGARDING WHAT WILL CERTAINLY BE A SHARP TEMP
GRADIENT...AND ONLY MADE MINOR ADJUSTMENTS TO PREVIOUS
FORECAST...AIMING FOR A RANGE FROM UPPER 50S FAR NORTH...MID 60S
TO LOW 70S TRI CITIES AREA...AND LOW 80S FAR SOUTHEAST IN THE
HEBRON-BELOIT CORRIDOR. AGAIN THOUGH...5+ DEGREE DEVIATIONS FROM
CURRENT FORECAST ARE VERY POSSIBLE IF NOT LIKELY. PONDERED GOING
WITH A NON-DIURNAL TEMP TREND BEHIND THE FRONT...BUT MODELS ARE
NOT REALLY SHOWING MUCH OF AN AFTERNOON DROP SO STUCK WITH
TRADITIONAL MID-LATE AFTERNOON HIGHS ALL AREAS FOR NOW. THIS COLD
FRONT WILL NOT EXACTLY BLAST THROUGH THE AREA...AND BY SUNSET WILL
JUST BE REACHING FAR SOUTHEAST ZONES...WHILE MOST OF THE CWA WILL
ALREADY BE IN SUSTAINED NORTH WINDS 15-20 MPH.
WEDNESDAY NIGHT IS CLEARLY STILL THE MAIN 12-HOUR WINDOW FOR
POTENTIALLY DECENT RAIN AMOUNTS...AND ACTUALLY RAISED POPS INTO
THE 60-70 PERCENT RANGE ACROSS MUCH OF THE EASTERN CWA...WHILE
LEAVING SOUTHWEST AREAS IN THE 40-50 PERCENT RANGE. IN
SHORT...LARGE SCALE FORCING/MID LEVEL FRONTOGENESIS RAMPS UP AS A
POTENT OPEN WAVE OVER THE CENTRAL ROCKIES MOVES INTO THE CENTRAL
PLAINS...FEATURING A 110+KT 300MB JET STREAK. LEFT THE POP/WEATHER
GRIDS AS ONE 12-HOUR BLOCK FOR NOW...BUT GENERAL THINKING IS THAT
MOST WIDESPREAD COVERAGE OF SHOWERS/STORMS WILL HOLD OFF UNTIL
NEAR/AFTER MIDNIGHT...UNLESS SOME EVENING ACTIVITY FLARES UP IN
THE FAR SOUTH/SOUTHEAST NEAR THE MAIN SURFACE FRONT. LATEST NAM
CONTINUES TO SHOW A HEALTHY CORRIDOR OF MUCAPE 1500+ J/KG IN THE
850-700MB LAYER MAINLY ACROSS THE SOUTHEAST 1/2 OF THE
CWA...DROPPING OFF SHORTLY TO THE NORTHWEST. HOWEVER...WILL KEEP
ISOLATED THUNDER EVEN IN THIS NORTHWEST AREAS. WITH VERY STRONG
DEEP-LAYER SHEAR OF 60+ KNOTS MOVING IN...HAVE INCREASING CONCERNS
THAT AT LEAST MARGINALLY SEVERE HAIL COULD OCCUR IN SOUTHEAST
COUNTIES...AND DESPITE SPC KEEPING THE OFFICIAL DAY2 SLIGHT RISK
OUTLOOK JUST EAST OF THE CWA...AT LEAST FOR NOW...WILL GO AHEAD
AND ADD THIS MENTION TO THE HAZARDOUS WEATHER OUTLOOK AS THESE
STRONG DYNAMICS ARE HARD TO IGNORE. DEPENDING ON HOW WIDESPREAD
STORMS ARE...COULD FORESEE SOME FORTUNATE AREAS RECEIVING IN
EXCESS OF ONE-HALF INCH OF RAIN BUT THIS WILL PROBABLY BE THE
EXCEPTION. ALTHOUGH SOME SNOW OR RAIN/SNOW MIX COULD TRY
DEVELOPING IN WESTERN NEBRASKA IN THE COLDER AIR WELL BEHIND THE
FRONT...LATEST CONSENSUS IS THAT WINTRY PRECIP WED NIGHT SHOULD
FOCUS AT LEAST 50 MILES WEST OF THE CWA...AND THUS WILL KEEP ANY
SNOW MENTION OUT FOR NOW.
THURSDAY...SPLIT THE DAY INTO 6-HOUR BLOCKS...WITH ALL PRECIP GONE
BY THE AFTERNOON HOURS...AND POTENTIALLY EVEN GONE BY MID-MORNING
IN MOST AREAS PER SOME OF THE LATEST TRENDS INCLUDING THE 00Z
ECMWF...WHICH QUICKLY SHUTS OFF THE MID LEVEL LIFT/SATURATION FROM
NORTHWEST-SOUTHEAST. LATER ADJUSTMENTS WILL BE NEEDED...BUT FOR NOW
KEPT 20-40 POPS ACROSS MOST OF THE CWA IN THE MORNING FOR GENERAL
LIGHT RAIN...WITH NO THUNDER MENTION AND STILL NO SNOW
MENTION...ALTHOUGH SUPPOSE A FEW FLURRIES COULD SNEAK INTO FAR
NORTHWEST ZONES JUST BEFORE PRECIP SHUTS OFF FOR GOOD GIVEN
SURFACE TEMPS FORECAST TO DROP INTO THE MID 30S EARLY THURSDAY
MORNING. OTHERWISE...EXPECT INCREASING SUNSHINE AS THE DAY WEARS
ON...ALTHOUGH IT WILL REMAIN QUITE BREEZY WITH SUSTAINED NORTH
WINDS AROUND 20 MPH WITH GUSTS TO AROUND 30 MPH. FOR HIGH
TEMPS...RAW NAM VALUES ARE WELL INTO THE MID 50S ALL AREAS...BUT
WAS NOT WILLING TO GO QUITE THIS WARM YET...AND THUS ONLY MADE
MINOR ADJUSTMENTS TO PREVIOUS FORECAST WITH MOST NEB ZONES TOPPING
OUT UPPER 40S AND KS LOWER 50S.
THURS NIGHT...THIS LOOKS TO BE THE MOST UNEVENTFUL PERIOD OF THE
NEXT 72 HOURS...AS AN EXPANSIVE SURFACE RIDGE AXIS SETTLES INTO
THE REGION FROM THE NORTH...AND ANY LIGHT SNOW ACCUMULATIONS
ASSOCIATED WITH TRAILING MID LEVEL SHORTWAVE ENERGY AND LOW LEVEL
UPSLOPE FLOW SHOULD REMAIN NO CLOSER THAN THE NEB/CO/KS BORDER
AREA. DESPITE A POTENTIAL INCREASE IN MID LEVEL CLOUDS...OPTED TO
LOWER LOW TEMPS 2-3 DEGREES FROM PREVIOUS FCST AND POSSIBLY NOT
ENOUGH...BUT AT LEAST GETTING ALL AREAS INTO THE SUB-FREEZING
26-32 RANGE.
LONG TERM...STARTING 12Z FRIDAY...THE LONGWAVE TROUGH ACROSS THE
WEST COAST THIS MORNING WILL BE CENTERED OVER THE PLAINS ON
FRIDAY...WITH SEVERAL EMBEDDED WEAK DISTURBANCES EXPECTED TO HAVE
LITTLE IMPACT IN THE WAY OF CHANCES FOR PRECIP ACROSS THE LOCAL
AREA. SOME DISCREPANCIES EVIDENT WITH THE HANDLING OF THIS TROUGH
AS IT PUSHES EAST LATE IN THE WEEKEND...WITH THE EC QUICKLY BUILDING
A RIDGE OVER THE INTERMOUNTAIN WEST RESULTING IN RISING HEIGHTS
ACROSS THE PLAINS...IN RESPONSE TO THE LONGWAVE TROUGH INTERACTS
WITH A TROPICAL DISTURBANCE OFF THE EASTERN SEABOARD...AND THE
LATEST GFS DEPICTING A MORE ZONAL WEST TO NORTHWEST FLOW ACROSS THE
REGION BY EARLY NEXT WEEK...AS THE AFOREMENTIONED TROPICAL
DISTURBANCE INSTEAD TRACKS OUT INTO THE OPEN ATLANTIC. EITHER
WAY...THIS APPEARS TO BE A DRY PATTERN FOR THE LOCAL AREA AS THERE
ARE NO SIGNIFICANT FEATURES FORECAST TO IMPACT THE AREA IN THE
DIVERGENT UPPER LEVEL FLOW PATTERNS DEPICTED AMONGST THE LONG TERM
MODELS. THEREFORE...EXPECT DRY CONDITIONS...WITH CONTINUED
UNSEASONABLY COOL TEMPERATURES...TO AT LEAST START THE EXTENDED
PERIODS...WITH TEMPERATURES POSSIBLY WARMING CLOSER TO
CLIMATOLOGY...WHILE REMAINING DRY...EARLY NEXT WEEK IF THE EC
SOLUTION ENDS UP BEING CORRECT. HOWEVER...DUE TO THE UNCERTAINTY OF
THE SYNOPTIC SCALE PATTERN EARLY NEXT WEEK...STUCK WITH ALLBLEND
MODEL SOLUTION THIS MORNING...WITH NO NOTABLE TWEAKS TO SPEAK OF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION/UPDATE...BRYANT
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1111 AM CDT TUE OCT 23 2012
.UPDATE...MORNING UPPER AIR ANALYSIS INDICATES LONG WAVE TROUGHING
OVER THE WESTERN HALF OF THE CONUS AND RIDGING OVER THE EAST. MID
AND UPPER LEVEL JET ENERGY EXTENDS FROM CALIFORNIA...NORTHEAST
ACROSS THE ROCKY MOUNTAIN RANGE INTO THE NORTHERN PLAINS...THEN
INTO SOUTH CENTRAL CANADA AND THEN EAST/SOUTHEAST INTO
SOUTHEASTERN CANADA AND THE NORTHEASTERN CONUS. TROPOSPHERIC FLOW
OVER THE CENTRAL PLAINS IS NOT PARTICULARLY STRONG AS A
RESULT...WITH THE WIND PEAKING OUT AT AROUND 70KTS NEAR 200MB.
WATER VAPOR IMAGERY INDICATES INCREASED VALUES OF MID LEVEL
MOISTURE EXTENDING ALONG THE JET AXIS FROM THE WESTERN CONUS INTO
SOUTH CENTRAL CANADA...HOWEVER MUCH OF THIS MID LEVEL MOISTURE
REMAINS NORTHWEST OF OUR AREA. AT THE SURFACE A STATIONARY FRONT
IS NOTED EXTENDING FROM SOUTHWESTERN IOWA...SOUTHWEST TO NEAR
KCNK...KGBD AND KDDC. THE LOW LEVEL WIND FIELD ACROSS OUR CWA
REMAINS FAIRLY LIGHT THIS MORNING...HOWEVER THE PREDOMINANT WIND
DIRECTION REMAINS FROM THE EAST/NORTHEAST DUE TO THE LOW LEVEL
BAROCLINIC ZONE TO OUR SOUTHEAST. ISENTROPIC UPGLIDE AND
SATURATION ACROSS THE LOW LEVEL BAROCLINIC ZONE...PRIMARILY ALONG
THE 290-295K SURFACES...CONTINUES TO PROMOTE WIDESPREAD STRATUS
ACROSS THE REGION THIS MORNING...WITH CEILINGS HOLDING GENERALLY
IN THE 100-300FT AGL RANGE ACROSS OUR AREA. IN ADDITION TO THIS
STRATUS...LOW LEVEL MOISTURE FLUX INTO THE AREA IS ALSO WORKING TO
PROMOTE CONTINUED FOG ACROSS MUCH OF THE AREA...WITH ENOUGH LOW
LEVEL TURBULENT MIXING FOR DRIZZLE AS WELL...PRIMARILY ACROSS OUR
EASTERN CWA. AS OF 1530Z THE LOWEST VISIBILITIES EXIST ALONG A
LINE FROM KAUH...TO KGRI...TO KEAR...TO KHDE AND KPHG...WHICH IS
WHERE VISIBILITY RESTRICTIONS OF 1/4SM TO 1/2SM ARE IN EXISTENCE.
TO THE NORTHWEST AND SOUTHEAST OF THIS LINE...VISIBILITY
RESTRICTIONS OF AROUND 1SM ARE BEING OBSERVED.
IMPROVEMENTS IN VISIBILITY HAVE BEEN NOTED ACROSS MUCH OF THE CWA
THROUGH PAST FEW HOURS WITH MOST LOCATIONS ACROSS OUR CWA NOW
ABOVE 1/4SM. AS A RESULT...THE DENSE FOG ADVISORY WAS LET GO AT
15Z. THAT BEING SAID...FOG...WITH VISIBILITY RESTRICTIONS
GENERALLY BETWEEN 1/2SM AND 1SM...STILL PERSISTS ACROSS THE AREA
AND WILL LIKELY BE OBSERVED THROUGH AT LEAST MIDDAY. BIGGEST
QUESTION FOR THE REST OF TODAY IS WHETHER OR NOT ENOUGH DIABATIC
HEATING WILL BE REALIZED FOR COMPLETE FOG DISSIPATION. THE CURRENT
HOPE IS THAT THE LOW LEVEL BAROCLINIC ZONE...CURRENTLY TO OUR
SOUTHEAST...WILL MAKE ENOUGH PROGRESS NORTH/NORTHWEST ACROSS OUR
AREA...THUS PUSHING THE BEST ISENTROPIC UPGLIDE TO OUR NORTH AND
CARRYING THE CLOUD COVER WITH IT. WITH CLOUD COVER DIMINISHING
OVER MUCH OF OUR AREA AND INCREASING DIABATIC HEATING...ENOUGH OF
A LOW LEVEL DEWPOINT DEPRESSION SHOULD PRESENT ITSELF FOR COMPLETE
FOG DISSIPATION AND SUNNIER SKIES THIS AFTERNOON. IF HOWEVER THE
LOW LEVEL BAROCLINIC ZONE DOES NOT MAKE AS MUCH PROGRESS
NORTH/NORTHWEST AS CURRENTLY EXPECTED...THEN THIS AFTERNOON COULD
TURN OUT BEING MUCH CLOUDIER THAN FORECAST...WITH FOG POTENTIALLY
PERSISTING THROUGH MUCH OF THE DAY. WITH CURRENT SHORT TERM
GUIDANCE SUGGESTING SUNNIER SKIES ACROSS MOST ALL OF THE CWA THIS
AFTERNOON...WILL STAY THE COURSE AND CONTINUE PRESENT PARTLY
CLOUDY SKIES WITH HIGHS IN THE 60S AND 70S FOR THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 556 AM CDT TUE OCT 23 2012/
AVIATION...12Z KGRI TAF...STRATUS CONTINUES TO COVER A GOOD
PORTION OF THE CENTRAL PLAINS THIS MORNING WITH LIFR/IFR CIGS
MIXED THROUGHOUT AREAS OF FG/BR/-DZ. EXPECT THE LIFR/IFR
CONDITIONS WILL PERSIST THROUGH AROUND 23/16Z...WHEN CIGS AND
VISIBILITIES ARE EXPECTED TO BEGIN TO IMPROVE MORE SUBSTANTIALLY
AS WINDS BEGIN TO INCREASE OUT OF THE SOUTH AND SOME MIXING ALLOWS
FOR CIGS/VSBYS TO BEGIN TO LIFT/IMPROVE. THIS IMPROVING TREND IS
EXPECTED TO CONTINUE THROUGH EARLY AFTERNOON...WITH A RETURN TO
VFR CIGS/VSBYS EXPECTED BY 23/19Z...AS INDICATED BY LATEST SHORT
TERM GUIDANCE.
PREV DISCUSSION... /ISSUED 516 AM CDT TUE OCT 23 2012/
SHORT TERM...THROUGH THURSDAY NIGHT. ANOTHER NIGHT...AND ANOTHER
SET OF SEVERAL TRICKY FORECAST ELEMENTS DURING THE NEXT 72
HOURS...NAMELY HIGH TEMPS AND PRECIP/FOG TRENDS...AND WHETHER ANY
STORMS WED NIGHT MIGHT GO SEVERE.
09Z OBJECTIVE SURFACE ANALYSIS CONFIRMS THAT THE ENTIRE CWA LIES
NORTH OF A QUASI-STATIONARY BOUNDARY SNAKING EAST-NORTHEAST ACROSS
SOUTHERN/EASTERN KANSAS AND EXTENDING FROM A WEAK 1003MB LOW IN
SOUTHEAST CO. BREEZES ACROSS THE CWA RANGE FROM LIGHT/VARIABLE TO
LIGHT EASTERLY...WITH LITTLE IF ANY TEMP/DEWPOINT DEPRESSION WITH
VALUES RANGING GENERALLY 47-53 ALL AREAS. AS EXPECTED 24 HOURS
AGO...VARYING DEGREES OF FOG HAVE SETTLED IN OVERNIGHT...WITH THE
ENTIRE CWA SEEING NO BETTER THAN 2-3 MILE VISIBILITY...AND THE MOST
CONCENTRATED ZONE OF DENSE FOG 1/4 MILE OR LOWER VSBY FOCUSED FROM
I-80 SOUTHWARD INTO KANSAS PER AUTOMATED OBS AND WEBCAMS. LIGHT
DRIZZLE HAS SEEMINGLY BEEN OFF AND ON OVERNIGHT...BUT IS LIKELY
STILL PRESENT IN MUCH OF THE CWA. ALOFT...WATER VAPOR SATELLITE
IMAGERY AND LATEST MODEL DATA CONFIRM BROAD WEST- SOUTHWEST FLOW
OVER THE CENTRAL PLAINS...WHICH IS POSITIONED DOWNSTREAM FROM A
LARGE SCALE TROUGH ANCHORED ACROSS THE PACIFIC NORTHWEST WITH A
CLOSED 500MB LOW OFF THE WASHINGTON STATE COAST. CLOSER TO
HOME...A SMALL SCALE SHORTWAVE TROUGH IS CURRENTLY DEPARTING
EASTWARD ACROSS MO...PROMOTING CONSIDERABLE ELEVATED THUNDERSTORM
ACTIVITY IN THAT AREA.
STARTING OFF EARLY THIS MORNING...THE MOST IMMEDIATE ISSUE IS THE
ONGOING CWA-WIDE DENSE FOG ADVISORY VALID THROUGH 15Z...AND WILL
LET IT RIDE AS-IS FOR NOW. TECHNICALLY SPEAKING...AUTOMATED OBS
SUGGEST THAT SO FAR THE MAJORITY OF ANY LOCALLY DENSE FOG HAS BEEN
CONFINED TO AREAS SOUTH OF THE I-80 CORRIDOR...BUT VARIOUS SHORT
TERM VISIBILITY GUIDANCE FROM THE HRRR/SREF SUGGEST THAT A
NORTHWARD EXPANSION OF DENSE FOG IS QUITE POSSIBLE YET THIS
MORNING...AND AM NOT ABOUT TO CANCEL ANY OF THIS ADVISORY UNTIL
TRENDS CAN BE MONITORED FOR AT LEAST A FEW MORE HOURS. IN
FACT...AM STARTING TO EVEN WONDER IF THE 15Z EXPIRATION TIME WILL
BE LONG ENOUGH...WITH BOTH THE HRRR AND HOURLY GFS LAMP GUIDANCE
SUGGESTING THAT SOME AREAS COULD REMAIN RATHER SOCKED IN UNTIL AT
LEAST 16Z-17Z. DAY SHIFT WILL HAVE TO KEEP AN EYE ON THE POSSIBLE
NEED FOR AN EXTENSION. AS FOR THE OFF AND ON LIGHT DRIZZLE SUCH AS
OBSERVED HERE AT THE WFO TONIGHT...HAVE IT MENTIONED CWA-WIDE
THROUGH 12Z...BUT HAVE THEN ATTEMPTED TO CONFINE IT TO ONLY A
HANDFUL OF COUNTIES EAST OF HWY 281 POST-SUNRISE...WHERE NAM
SOUNDINGS INDICATED THAT THE SATURATED LAYER WOULD REMAIN
DEEPER...GENERALLY NEAR/IN EXCESS OF 2500 FT. THAT BEING
SAID...CANNOT COMPLETELY RULE OUT POST-SUNRISE LIGHT DRIZZLE EVEN
IN THE TRI-CITIES AREA WESTWARD GIVEN SUCH A MOIST LOW LEVEL
PROFILE. AS FOR SKY COVER...CONFIDENCE IS CONSIDERABLY HIGHER
TODAY THAT MUCH OF THE CWA WILL SEE AT LEAST A FEW HOURS OF PARTLY
TO MOSTLY SUNNY SKIES AT SOME POINT...BUT EXACTLY WHEN IS STILL
IN QUESTION. HAVE GENERALLY FOLLOWED THE 00Z/06Z NAM SOLUTION OF
KEEPING NEARLY ALL AREAS SOCKED IN WITH STRATUS AND AT LEAST LIGHT
FOG THROUGH THE MORNING HOURS...BUT THEN ERODING FROM WEST-EAST
THROUGH THE AFTERNOON WEARS ON AS EVIDENCED BY THE 900MB RELATIVE
HUMIDITY FIELD. THIS MEANS THAT FAR EASTERN COUNTIES ALONG THE HWY
81 WOULD BE LAST TO SEE ANY CLEARING. AFTER BUSTING HIGH TEMPS BY
10+ DEGREES YESTERDAY DUE TO WIDESPREAD LOW STRATUS...AM IN NO
HURRY TO GO WITH THE WARM END OF AVAILABLE GUIDANCE/MODEL
SOLUTIONS TODAY ESPECIALLY IN EASTERN ZONES. AFTER TRYING VARIOUS
SOLUTIONS ON FOR SIZE...ENDED UP GOING WITH THE 00Z NAM ALMOST
EXACTLY...AS ITS TEMP FIELD SEEMED TO BEST-CAPTURE THE GRADUAL
WEST-EAST CLEARING. THIS RESULTS IN A DECENT RANGE FROM NEAR 80
FAR WEST ...LOW-MID 70S CENTRAL AND UPPER 60S EAST. PLEASE NOTE
THESE VALUES ARE AT LEAST A FEW DEGREES COOLER THAN PREVIOUS
FORECAST ALL AREAS...AND AS MUCH AS 5-8 DEGREES COOLER IN THE
EAST. LIKE YESTERDAY...COULD EASILY FORESEE HIGHS BEING OFF BY 5+
DEGREES DEPENDING ON STRATUS/FOG TRENDS.
TONIGHT...KEPT OUT ALL MENTION OF PRECIP CWA-WIDE...AND AM NOT
EXPECTING A DENSE FOG REPEAT SUCH AS THE ONGOING ONE...BUT DID
INSERT A PATCHY FOG MENTION INTO SEVERAL COUNTIES NORTH OF I-80
AFTER MIDNIGHT IN CLOSEST PROXIMITY TO THE HIGHEST BOUNDARY LAYER
RELATIVE HUMIDITY POOLING IN THE VICINITY OF THE LEADING EDGES OF
THE INVADING COLD FRONT. CLOUD TRENDS TONIGHT ARE CERTAINLY A
CHALLENGE...WITH THE POTENTIAL FOR QUITE AN INCREASE IN STRATUS
TOWARD SUNRISE NEAR THIS BOUNDARY...FOLLOWING WHAT SHOULD BE A
FAIRLY CLEAR EVENING FOR MOST AREAS. ALOFT...THE BIG PICTURE
INVOLVES A LEAD SHORTWAVE TRACKING ACROSS FAR SOUTH CENTRAL
CANADA...WHICH HELPS DRIVE THE SURFACE FRONT INTO THE NORTHERN
CWA...WHILE A TROUGH AXIS SETS UP FROM SOUTHWEST-NORTHEAST ACROSS
KS. KEPT LOWS SIMILAR TO PREVIOUS FORECAST AND A GUIDANCE
BLEND...RANGING FROM LOW-MID 40S NORTHWEST TO UPPER 50S/NEAR 60
SOUTHEAST WHERE DEWPOINTS WILL BE ON THE INCREASE.
WEDNESDAY...OTHER THAN THE LINGERING PATCHY FOG MENTION NORTH IN
THE MORNING...HAVE KEPT OUT ANY OTHER WEATHER MENTION THROUGH
SUNSET...AS THE GENERAL MODEL CONSENSUS IS TO KEEP ANY LIGHT
DAYTIME DRIZZLY PRECIP NORTHEAST OF THE CWA...AND ANY LATE-DAY
CONVECTION ALONG/NEAR THE INVADING COLD FRONT JUST SOUTHEAST OF
THE CWA. THAT BEING SAID...SKY COVER AND TEMP TRENDS ARE AGAIN
QUITE A CHALLENGE...AS QUITE A BIT OF STRATUS SHOULD DOMINATE MUCH
OF THE NORTHWEST CWA WITH MORE SUNSHINE SOUTHEAST.
FORTUNATELY...THE LATEST MODEL RUNS ARE IN REASONABLY GOOD
AGREEMENT REGARDING WHAT WILL CERTAINLY BE A SHARP TEMP
GRADIENT...AND ONLY MADE MINOR ADJUSTMENTS TO PREVIOUS
FORECAST...AIMING FOR A RANGE FROM UPPER 50S FAR NORTH...MID 60S
TO LOW 70S TRI CITIES AREA...AND LOW 80S FAR SOUTHEAST IN THE
HEBRON-BELOIT CORRIDOR. AGAIN THOUGH...5+ DEGREE DEVIATIONS FROM
CURRENT FORECAST ARE VERY POSSIBLE IF NOT LIKELY. PONDERED GOING
WITH A NON-DIURNAL TEMP TREND BEHIND THE FRONT...BUT MODELS ARE
NOT REALLY SHOWING MUCH OF AN AFTERNOON DROP SO STUCK WITH
TRADITIONAL MID-LATE AFTERNOON HIGHS ALL AREAS FOR NOW. THIS COLD
FRONT WILL NOT EXACTLY BLAST THROUGH THE AREA...AND BY SUNSET WILL
JUST BE REACHING FAR SOUTHEAST ZONES...WHILE MOST OF THE CWA WILL
ALREADY BE IN SUSTAINED NORTH WINDS 15-20 MPH.
WEDNESDAY NIGHT IS CLEARLY STILL THE MAIN 12-HOUR WINDOW FOR
POTENTIALLY DECENT RAIN AMOUNTS...AND ACTUALLY RAISED POPS INTO
THE 60-70 PERCENT RANGE ACROSS MUCH OF THE EASTERN CWA...WHILE
LEAVING SOUTHWEST AREAS IN THE 40-50 PERCENT RANGE. IN
SHORT...LARGE SCALE FORCING/MID LEVEL FRONTOGENESIS RAMPS UP AS A
POTENT OPEN WAVE OVER THE CENTRAL ROCKIES MOVES INTO THE CENTRAL
PLAINS...FEATURING A 110+KT 300MB JET STREAK. LEFT THE POP/WEATHER
GRIDS AS ONE 12-HOUR BLOCK FOR NOW...BUT GENERAL THINKING IS THAT
MOST WIDESPREAD COVERAGE OF SHOWERS/STORMS WILL HOLD OFF UNTIL
NEAR/AFTER MIDNIGHT...UNLESS SOME EVENING ACTIVITY FLARES UP IN
THE FAR SOUTH/SOUTHEAST NEAR THE MAIN SURFACE FRONT. LATEST NAM
CONTINUES TO SHOW A HEALTHY CORRIDOR OF MUCAPE 1500+ J/KG IN THE
850-700MB LAYER MAINLY ACROSS THE SOUTHEAST 1/2 OF THE
CWA...DROPPING OFF SHORTLY TO THE NORTHWEST. HOWEVER...WILL KEEP
ISOLATED THUNDER EVEN IN THIS NORTHWEST AREAS. WITH VERY STRONG
DEEP-LAYER SHEAR OF 60+ KNOTS MOVING IN...HAVE INCREASING CONCERNS
THAT AT LEAST MARGINALLY SEVERE HAIL COULD OCCUR IN SOUTHEAST
COUNTIES...AND DESPITE SPC KEEPING THE OFFICIAL DAY2 SLIGHT RISK
OUTLOOK JUST EAST OF THE CWA...AT LEAST FOR NOW...WILL GO AHEAD
AND ADD THIS MENTION TO THE HAZARDOUS WEATHER OUTLOOK AS THESE
STRONG DYNAMICS ARE HARD TO IGNORE. DEPENDING ON HOW WIDESPREAD
STORMS ARE...COULD FORESEE SOME FORTUNATE AREAS RECEIVING IN
EXCESS OF ONE-HALF INCH OF RAIN BUT THIS WILL PROBABLY BE THE
EXCEPTION. ALTHOUGH SOME SNOW OR RAIN/SNOW MIX COULD TRY
DEVELOPING IN WESTERN NEBRASKA IN THE COLDER AIR WELL BEHIND THE
FRONT...LATEST CONSENSUS IS THAT WINTRY PRECIP WED NIGHT SHOULD
FOCUS AT LEAST 50 MILES WEST OF THE CWA...AND THUS WILL KEEP ANY
SNOW MENTION OUT FOR NOW.
THURSDAY...SPLIT THE DAY INTO 6-HOUR BLOCKS...WITH ALL PRECIP GONE
BY THE AFTERNOON HOURS...AND POTENTIALLY EVEN GONE BY MID-MORNING
IN MOST AREAS PER SOME OF THE LATEST TRENDS INCLUDING THE 00Z
ECMWF...WHICH QUICKLY SHUTS OFF THE MID LEVEL LIFT/SATURATION FROM
NORTHWEST-SOUTHEAST. LATER ADJUSTMENTS WILL BE NEEDED...BUT FOR NOW
KEPT 20-40 POPS ACROSS MOST OF THE CWA IN THE MORNING FOR GENERAL
LIGHT RAIN...WITH NO THUNDER MENTION AND STILL NO SNOW
MENTION...ALTHOUGH SUPPOSE A FEW FLURRIES COULD SNEAK INTO FAR
NORTHWEST ZONES JUST BEFORE PRECIP SHUTS OFF FOR GOOD GIVEN
SURFACE TEMPS FORECAST TO DROP INTO THE MID 30S EARLY THURSDAY
MORNING. OTHERWISE...EXPECT INCREASING SUNSHINE AS THE DAY WEARS
ON...ALTHOUGH IT WILL REMAIN QUITE BREEZY WITH SUSTAINED NORTH
WINDS AROUND 20 MPH WITH GUSTS TO AROUND 30 MPH. FOR HIGH
TEMPS...RAW NAM VALUES ARE WELL INTO THE MID 50S ALL AREAS...BUT
WAS NOT WILLING TO GO QUITE THIS WARM YET...AND THUS ONLY MADE
MINOR ADJUSTMENTS TO PREVIOUS FORECAST WITH MOST NEB ZONES TOPPING
OUT UPPER 40S AND KS LOWER 50S.
THURS NIGHT...THIS LOOKS TO BE THE MOST UNEVENTFUL PERIOD OF THE
NEXT 72 HOURS...AS AN EXPANSIVE SURFACE RIDGE AXIS SETTLES INTO
THE REGION FROM THE NORTH...AND ANY LIGHT SNOW ACCUMULATIONS
ASSOCIATED WITH TRAILING MID LEVEL SHORTWAVE ENERGY AND LOW LEVEL
UPSLOPE FLOW SHOULD REMAIN NO CLOSER THAN THE NEB/CO/KS BORDER
AREA. DESPITE A POTENTIAL INCREASE IN MID LEVEL CLOUDS...OPTED TO
LOWER LOW TEMPS 2-3 DEGREES FROM PREVIOUS FCST AND POSSIBLY NOT
ENOUGH...BUT AT LEAST GETTING ALL AREAS INTO THE SUB-FREEZING
26-32 RANGE.
LONG TERM...STARTING 12Z FRIDAY...THE LONGWAVE TROUGH ACROSS THE
WEST COAST THIS MORNING WILL BE CENTERED OVER THE PLAINS ON
FRIDAY...WITH SEVERAL EMBEDDED WEAK DISTURBANCES EXPECTED TO HAVE
LITTLE IMPACT IN THE WAY OF CHANCES FOR PRECIP ACROSS THE LOCAL
AREA. SOME DISCREPANCIES EVIDENT WITH THE HANDLING OF THIS TROUGH
AS IT PUSHES EAST LATE IN THE WEEKEND...WITH THE EC QUICKLY BUILDING
A RIDGE OVER THE INTERMOUNTAIN WEST RESULTING IN RISING HEIGHTS
ACROSS THE PLAINS...IN RESPONSE TO THE LONGWAVE TROUGH INTERACTS
WITH A TROPICAL DISTURBANCE OFF THE EASTERN SEABOARD...AND THE
LATEST GFS DEPICTING A MORE ZONAL WEST TO NORTHWEST FLOW ACROSS THE
REGION BY EARLY NEXT WEEK...AS THE AFOREMENTIONED TROPICAL
DISTURBANCE INSTEAD TRACKS OUT INTO THE OPEN ATLANTIC. EITHER
WAY...THIS APPEARS TO BE A DRY PATTERN FOR THE LOCAL AREA AS THERE
ARE NO SIGNIFICANT FEATURES FORECAST TO IMPACT THE AREA IN THE
DIVERGENT UPPER LEVEL FLOW PATTERNS DEPICTED AMONGST THE LONG TERM
MODELS. THEREFORE...EXPECT DRY CONDITIONS...WITH CONTINUED
UNSEASONABLY COOL TEMPERATURES...TO AT LEAST START THE EXTENDED
PERIODS...WITH TEMPERATURES POSSIBLY WARMING CLOSER TO
CLIMATOLOGY...WHILE REMAINING DRY...EARLY NEXT WEEK IF THE EC
SOLUTION ENDS UP BEING CORRECT. HOWEVER...DUE TO THE UNCERTAINTY OF
THE SYNOPTIC SCALE PATTERN EARLY NEXT WEEK...STUCK WITH ALLBLEND
MODEL SOLUTION THIS MORNING...WITH NO NOTABLE TWEAKS TO SPEAK OF.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...BRYANT
SHORT TERM...PFANNKUCH
LONG TERM/AVIATION...ROSSI
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1254 PM CDT TUE OCT 23 2012
.DISCUSSION.../ISSUED AT 920 AM CDT/
DENSE FOG PERSISTING ACROSS NORTHEAST QUARTER OF THE FORECAST AREA
LONGER THAN EARLIER ANTICIPATED. FOR NOW...HAVE EXTENDED DENSE FOG
ADVISORY FOR SOUTHWEST MINNESOTA AND I-29 CORRIDOR FROM SIOUX FALLS
NORTHWARD UNTIL 10 AM...THOUGH HRRR SUGGESTS LOW VISIBILITY MAY LAST
EVEN LONGER THAN THAT...ESPECIALLY ALONG AND WEST/UPSLOPE OF BUFFALO
RIDGE. WILL CONTINUE TO EVALUATE THAT OVER THE NEXT HOUR AND ADJUST
AGAIN IF NECESSARY PRIOR TO 15Z. FOG/STRATUS WILL HOLD TEMPERATURES
DOWN ACCORDINGLY...AND HAVE BEGUN TO TREND AFTERNOON READINGS LOWER
ACROSS THE NORTHEAST CWA...THOUGH AGAIN...FURTHER ADJUSTMENTS MAY BE
NECESSARY IF FOG PERSISTS LATER INTO THE MORNING. LEFT HIGHS IN THE
70S ALONE ACROSS THE SOUTHWEST CWA...AS MODELS STILL SHOW BOUNDARY
AND ASSOCIATED SHIFT TO SOUTHWEST LOW LEVEL FLOW PUSHING INTO THAT
AREA DURING THE AFTERNOON. THIS SHOULD ALLOW DECENT DRYING/MIXING IN
AREAS WEST OF THE JAMES VALLEY.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
TOUGHEST CALL FOR THE 18Z TAF ISSUANCE IS SHORT TERM DISSIPATION OF
THE WIDESPREAD IFR/MVFR STRATUS FIELD. STRONG INVERSION ON KOAX AND
KABR MORNING RAOBS DO NOT LEND CONFIDENCE TO THE ABILITY TO MIX OUT
THE LOWER CEILINGS THIS AFTERNOON...AND LIKELY WILL DEPEND GREATLY
ON ADVECTION/MIXING ON EDGE TO RESULT IN CLEARING...WHICH IS DELAYED
ON CURRENT SET BY SEVERAL HOURS OVER PREVIOUS FORECAST FOR KSUX/KFSD.
IN FACT...CEILINGS MAY RETURN LOWER FOR A COUPLE HOURS EARLY THIS
AFTERNOON AROUND KFSD WITH ADVECTION FROM SOUTH...BACK INTO IFR
LEVELS. FRONTAL ZONE OUT ACROSS WESTERN SOUTH DAKOTA WILL PROGRESS
EASTWARD WILL HAVE BEST DRYING SURGE JUST AHEAD...IMPACTING KHON BY
MID AFTERNOON. FOLLOWING FRONTAL PASSAGE...LIKELY THAT SOME AREAS OF
MVFR OR IFR CEILINGS WILL SPREAD BACK SOUTHWARD INTO KHON...AND ALSO
DEVELOP FARTHER SOUTHEAST TOWARD KFSD/KSUX ALONG WITH INCREASED
MOISTURE LEVELS. FOR NOW...HAVE NOT MENTIONED ANY PRECIPITATION...
BUT POTENTIAL FOR SOME LIGHT DRIZZLE ONCE AGAIN TOMORROW MORNING FOR
KFSD/KSUX AREAS. /CHAPMAN
&&
.PREV DISCUSSION.../ISSUED AT 420 AM CDT/
BROAD SWATH OF STRATUS BLANKETING MUCH OF THE NORTHERN AND CENTRAL
PLAINS REMAINS THE PRIMARY CONCERN FOR TODAY. MODELS HOLD ONTO THE
LOW LEVEL MOISTURE THROUGH MUCH OF THE MORNING RESULTING IN THE
WIDESPREAD LOW CLOUDS AND PATCHY DRIZZLE AND FOG WILL LIKELY STICK
AROUND THROUGH MID TO LATE MORNING. SOUTHWESTERLY FLOW WILL BEGIN TO
INCREASE ACROSS THE WEST LATER THIS MORNING WHICH SHOULD BEGIN
MIXING DRIER AIR INTO THE LOW LEVELS WHICH SHOULD SCOUR OUT THE
CLOUDS BY AFTERNOON. THE BIG QUESTION IS HOW QUICKLY THE CLEARING
WILL WORK INTO OUR EASTERN HALF AND WHETHER OUR FAR NORTHEAST WILL
SEE SIGNIFICANT CLEARING BY LATE AFTERNOON. THIS WILL LARGE
IMPLICATIONS ON TEMPERATURE TRENDS...AS HEFTY WARM AIR ADVECTION
WILL EASILY PLACE HIGH TEMPERATURES IN THE MID TO UPPER 70S IN THE
WEST. DID KNOCK BACK HIGHS SLIGHTLY TO THE UPPER 60S IN OUR
NORTHEAST GIVEN THE POTENTIAL TO BE CLOUDY FOR THE BETTER PART OF
THE DAYLIGHT HOURS.
THE MILDER TEMPERATURES WILL BE SHORT LIVED AS A LARGE UPPER LEVEL
LOW TRACKS INTO THE SOUTHERN CANADIAN PRAIRIE PROVINCES BY WEDNESDAY
AND DROPS A COLD FRONT THROUGH THE NORTHERN PLAINS. THE SURFACE
FRONT DIGS THROUGH THE FORECAST AREA TUESDAY AFTERNOON AND TUESDAY
NIGHT THEN STALLS JUST SOUTH OF THE FORECAST AREA WITH LITTLE IMPACT
OUTSIDE OF SOME INCREASED CLOUD COVERAGE. ON WEDNESDAY...SURFACE LOW
PRESSURE DEVELOPS IN EASTERN KANSAS AND PUSHES NORTHEAST INTO
WESTERN IOWA LATE IN THE DAY. THE PRECISE TIMING OF THIS FEATURE AND
THE POTENTIAL LIFTING OF THE WARM FRONT INTO OUR SOUTHEASTERN
COUNTIES ARE STILL A BIT UNCERTAIN. HOWEVER...WITH INCREASED SHEAR
AND NAM MUCAPE APPROACHING 2000 J/KG NEAR THE BOUNDARY...COULD SEE
SOME THUNDERSTORM ACTIVITY IN ADDITION TO SHOWERS. A LARGE DETERRENT
TO ANY SURFACED BASED/SEVERE CONVECTION WILL BE THE STRONG CAPPING
IN PLACE IN THIS AREA. A SECOND AREA TO WATCH FOR POTENTIAL
PRECIPITATION ON WEDNESDAY WILL BE ACROSS THE FAR WESTERN CWA...WITH
STRONG 850 MB FRONTOGENESIS SETTING UP ACROSS CENTRAL AND
NORTHEASTERN SOUTH DAKOTA. WILL KEEP CHANCEY POPS IN PLACE FOR THE
DAY WITH LARGE UNCERTAINTY WITH THE BOUNDARY PLACEMENTS AND
CONDITIONAL CONVECTIVE POTENTIAL.
THE MID LEVEL TROUGH STARTS KICKING EASTWARD WEDNESDAY NIGHT WITH
THE MID LEVEL FRONTOGENESIS SHIFTING INTO OUR CENTRAL CWA BY
DAYBREAK THURSDAY. IT LOOKS LIKE A VERY STRONG POTENTIAL FOR SOME
DECENT RAINFALL WEDNESDAY NIGHT AND EARLY THURSDAY AND HAVE BOOSTED
POPS TO CATEGORICAL FOR THE CENTRAL AND EASTERN CWA. RAINFALL
AMOUNTS OF AROUND A QUARTER TO HALF INCH LOOK REASONABLE AT THIS
POINT. MUCH COOLER TEMPERATURES WILL ARRIVE DURING THIS TIME...WITH
TEMPERATURES ON THURSDAY SHOWING LITTLE TO NO DIURNAL CHANGE OR EVEN
SOME FALLING TEMPERATURES. HIGHS WILL BE IN THE 40S.
IN THE EXTENDED...BROAD UPPER LEVEL TROUGHING SETTLES OVER THE
CENTRAL STATES AND WILL KEEP COOL AND DRY CONDITIONS IN PLACE INTO
THE END OF THE WEEK. MODELS ARE IN DECENT AGREEMENT WITH THIS DRY
AND COLD PATTERN WHICH PLACE WITH HIGHS ONLY IN THE UPPER 30S TO MID
40S AND LOWS IN THE 20S. MODELS DO DIVERGE A BIT FOR THE WEEKEND
WITH A MORE ZONAL MID LEVEL PATTERN IN THE GFS BRINGING A WAVE
THROUGH THE MISSOURI VALLEY ON SUNDAY. MEANWHILE THE ECMWF ALSO
HINTS AT A WAVE...BUT DROPS IT THROUGH SOUTHWEST MINNESOTA. DID ADD
A SLIGHT CHANCE POP IN OUR NORTHEAST FOR SUNDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1227 PM CDT TUE OCT 23 2012
.SHORT TERM...TODAY THROUGH THURSDAY
350 AM CDT TUE OCT 23 2012
AT 3 AM...A WARM FRONT EXTENDED FROM SIOUX CITY IOWA /KSUX/ TO
MUSCATINE IOWA /KMUT/. THERE IS LITTLE WEATHER ASSOCIATED WITH
THIS FRONT. MEANWHILE FURTHER NORTH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WERE DEVELOPING ALONG A BAND OF 900 TO 800 MB
FRONTOGENESIS ACROSS SOUTHEAST MINNESOTA. THE RUC SHOWS THAT THIS
BAND OF FRONTOGENESIS LIFTS QUICKLY NORTHEAST OF THE INTERSTATE 90
CORRIDOR AND BY LATE MORNING IT EXTENDS FROM HUDSON WISCONSIN TO
MILWAUKEE. THE MESO MODELS SEEM TO HAVE A FAIRLY GOOD HANDLE ON
THIS...SO FOLLOWED THEM. FURTHER SOUTHEAST...A SHORT WAVE TROUGH
WILL BE LIFTING NORTHEAST THROUGH THE MID MISSISSIPPI RIVER VALLEY
INTO THE LOWER GREAT LAKES. THERE IS MODERATE 850 MB MOISTURE INTO
PARTS OF OF NORTHEAST IOWA AND SOUTHWEST WISCONSIN THROUGHOUT THIS
MORNING...SO KEPT A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS
IN THESE AREAS THROUGHOUT THIS MORNING.
FOR THIS AFTERNOON...WEAK 300K ISENTROPIC LIFT CONTINUES NORTH OF
THE WARM FRONT NORTH OF THE INTERSTATE 94 CORRIDOR. AS A
RESULT...KEPT ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST
FOR THIS AREA.
FOR TONIGHT...THE 23.00Z MODELS ARE IN GENERAL AGREEMENT THAT
THERE WILL BE WEAK TO MODERATE 850 MOISTURE TRANSPORT INTO THE
REGION. THE MESO MODELS /ARW...NMM...AND SPC WRF/ SUGGEST THAT
THERE WILL BE SOME ISOLATED SHOWERS AND THUNDERSTORMS...SO KEPT
THE 20 PERCENT PROBABILITY OF RAIN ACROSS THE ENTIRE AREA.
ON WEDNESDAY...THE MODELS ARE IN GENERAL AGREEMENT THAT A WARM AIR
MASS BETWEEN 850 MB AND 675 MB WILL ADVECT NORTHWARD IN ADVANCE OF
AN APPROACHING COLD FRONT. THIS CAP SHOULD GREATLY INHIBIT THE
DEVELOPMENT OF PRECIPITATION AHEAD OF THE APPROACHING COLD FRONT
FOR MUCH OF THE DAY...THUS WENT DRY IN THE MORNING...AND SLOWLY
INCREASED THE PRECIPITATION CHANCES ACROSS NORTHEAST
IOWA...SOUTHEAST MINNESOTA...AND WEST-CENTRAL AND NORTH-CENTRAL
WISCONSIN. THINKING THAT THE STRONG CAP WILL LIMIT ANY SHOWER AND
THUNDERSTORM DEVELOPMENT TO ALONG AND JUST AHEAD OF THE COLD
FRONT. THE 0-6 KM BULK SHEAR IS FAVORABLE FOR THE DEVELOPMENT OF
SUPERCELL THUNDERSTORM DEVELOPMENT. THE GFS GENERATES SOME LIGHT
SHOWERS AHEAD OF THIS FRONT...THUS...ITS MLCAPES ARE RUNNING
BETWEEN 1000 AND 1500 J/KG. MEANWHILE THE NAM/WRF IS DRY AND
ALLOWS TEMPERATURES TO CLIMB TO AROUND 80. THE COMBINATION OF
THESE TEMPERATURES AND MID 60 DEW POINTS /HIGHEST THIS LATE IN THE
YEAR SINCE OCTOBER 26 2010/ WILL RESULT IN THE ML CAPES AROUND
2500 J/KG. INITIALLY THINKING THAT THE CONVECTION WILL START TO
DEVELOP ALONG THE FRONT BETWEEN 24.19 AND 24.21Z AS ELEVATED CELLS
AND THEN BECOME SURFACE BASED BETWEEN 24.21Z AND 25.00Z. THE NAM
HAS A WEAK LOW ALONG THIS FRONT WHICH HELPS INCREASE THE 0-1KM
BULK SHEAR WHICH MAY POSSIBLY RESULT IN ISOLATED TORNADOES ACROSS
NORTH-CENTRAL IOWA AND SOUTH-CENTRAL AND SOUTHEAST MINNESOTA.
OTHERWISE...THE MAIN SEVERE WEATHER THREATS WILL BE LARGE HAIL AND
DAMAGING WIND DURING THE LATE AFTERNOON AND EARLY EVENING ACROSS
NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND WEST-CENTRAL WISCONSIN.
ON THURSDAY...THE MODELS STILL DIFFER ON THE TIMING OF THE FRONT.
THE GFS IS THE SLOWEST AND LINGER PRECIPITATION ACROSS THE ENTIRE
AREA THROUGH THE DAY. MEANWHILE THE GEM IS THE FASTEST AND HAS THE
AFTERNOON DRY. DUE TO THESE DIFFERENCES...DID NOT GET TOO FANCY
WITH TRYING TO TIME THE PRECIPITATION OUT OF THE AREA.
REGARDLESS...THE MOST NOTICEABLE FEATURE WILL BE THE RAPIDLY
FALLING TEMPERATURES IN THE WAKE OF THE FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
350 AM CDT TUE OCT 23 2012
ON THURSDAY NIGHT...THE MODELS WERE IN GOOD CONSENSUS THAT THE
PRECIPITATION WOULD BE ENDING ACROSS WESTERN WISCONSIN DURING THE
EVENING. AS A RESULT...CONFINED THE PRECIPITATION CHANCES TO THAT
TIME PERIOD.
ON MONDAY...THE 23.00Z GFS WAS VERY SIMILAR WITH ITS 22.18Z RUN AT
GENERATING SOME WARM AIR ADVECTION PRECIPITATION ACROSS THE AREA.
MEANWHILE THE ECMWF CONTINUE TO SHOW THAT THIS PRECIPITATION WILL
DRY UP AS IT HEADS INTO THE AREA. DUE TO THESE DIFFERENCES
MENTIONED A SLIGHT CHANCE OF PRECIPITATION NORTH OF AN OELWEIN
IOWA TO MEDFORD WISCONSIN LINE. THE PRECIPITATION HAS THE
POTENTIAL OF BEING A MIX OF RAIN AND SNOW IN THE EARLY MORNING.
HOWEVER SINCE IT WAS VERY UNCLEAR IT WAS EVEN GOING TO
OCCUR...JUST OPTED TO GO WITH RAIN FOR NOW.
&&
.AVIATION...THIS AFTERNOON THRU WEDNESDAY MORNING
1227 PM CDT TUE OCT 23 2012
IFR CLOUDS/BR/FG ASSOCIATED WITH A WARM AND VERY MOIST AIRMASS...AND
A WARM FRONT...MOVING NORTH ACROSS THE UPPER MIDWEST LOOK TO PREVAIL
ACROSS THE AREA THIS PERIOD. CIGS/VSBYS STRUGGLING TO IMPROVE ACROSS
THE AREA AT MID-DAY AS THE WARM FRONT LIFTS SLOWLY NORTH INTO THE
AREA AND SFC-850MB MOISTURE CONTINUES TO INCREASE. SOME IMPROVEMENT
TO MVFR CIGS ACROSS NORTHERN IA BEHIND THE FRONT AT MID DAY. DID
SPREAD SOME MVFR CIGS INTO BOTH KRST/KLSE LATER THIS AFTERNOON WITH
THE FRONT EXPECTED TO LIFT NORTH OF I-90. HOWEVER...MORE LOWER END
MVFR AND IFR CLOUD DECKS BEHIND THE FRONT OVER CENTRAL/SOUTHERN IA
TO ADVECT NORTH TONIGHT...AND LOWER WITH DIURNAL COOLING. WITH FG/BR
FAILING TO CLEAR THIS AFTERNOON...STAGE IS SET FOR IFR/LIFR VSBYS IN
FOG TONIGHT AS THE LOW LEVEL MOISTURE CONTINUES TO INCREASE AND THE
AIRMASS COOLS. CARRIED IFR/LIFR CIGS/VSBYS AT BOTH KRST/KLSE IN THE
05Z-15Z TIME-FRAME TONIGHT. AREA MAY END UP COVERED WITH A DENSE FOG
ADVISORY FOR THIS TIME PERIOD. CONDITIONS LOOK SLOW TO IMPROVE WED
WITH LITTLE CHANGE OF THE AIRMASS AND BROAD LOW LEVEL WARM
ADVECTION/ASCENT OVER THE AREA...AHEAD OF A STRONG COLD FRONT TO
MOVE INTO THE AREA WED NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
350 AM CDT TUE OCT 23 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1212 PM MDT TUE OCT 23 2012
.UPDATE...
AVIATION...18Z TAF ISSUANCE...FOG AND LOW CIGS HAVE LIFTED THIS
MORNING...WITH GUSTY WEST TO SOUTHWEST WINDS THE MAIN CONCERN
FOR TODAY. SE WYOMING TERMINALS WILL SEE GUSTS OF 30 OR 40
KNOTS WITH 20 TO 30 KTS ACROSS THE PANHANDLE AHEAD OF A COLD FRONT
THAT WILL DROP SOUTH ACROSS THE AREA AFTER 21Z. WINDS WILL SHIFT
TO THE NORTH AND THEN NORTHEAST BEHIND THE FRONT...AND SNOW WILL
DEVELOP AT KRWL...UP THROUGH KDGW AND TO THE NORTHEAST AFTER 03Z
OR SO AS THE NEXT STORM SYSTEM BEGINS TO IMPACT THE REGION. RJM
&&
.PREV DISCUSSION... /ISSUED 920 AM MDT TUE OCT 23 2012/
UPDATE...
WENT AHEAD AND LET THE HIGH WIND WARNING EXPIRE THIS MORNING AS
OBSERVED WINDS HAVE STAYED DOWN BELOW WARNING CRITERIA. THERE IS
STILL A CHANCE FOR WINDS TO BECOME STRONG AS WE MIX OUT...BUT DO
NOT THINK WE WILL HIT HIGH WIND WARNING CRITERIA ANY MORE TODAY.
STILL FAIRLY DENSE FOG OUT IN THE PANHANDLE AND WILL CONTINUE THE
SPS WE HAVE GOING THROUGH NOON. FOG MAY BURN OFF EARLIER THAN
THAT...BUT FOR NOW...WILL GO FOR NOON. DEFINITELY SOME QUESTIONS
ON THE UPCOMING WINTER EVENT THAT WE WILL NEED TO WORK OUT FOR THE
AFTERNOON PACKAGE. WAITING FOR THE 12Z MODEL RUNS TO MAKE ANY
DECISIONS ON HIGHLIGHTS.
CLAYCOMB
PREV DISCUSSION... /ISSUED 623 AM MDT TUE OCT 23 2012/
SHORT TERM...TODAY THROUGH THURSDAY...
LOTS OF FORECAST CONCERNS OVER THE SHORT TERM. WINDS HAVE BEEN
APPROACHING HIGH WIND CRITERIA IN THE ARLINGTON AREA OVER THE PAST
FEW HOURS...BUT HAVE GENERALLY REMAINED BELOW 50MPH. THE GFS SHOWS
700MB 50-60 KTS TO THE WEST OF THE LARAMIE RANGE THROUGH 12Z
BEFORE DECREASING TO 45 KTS BY 18Z. BELIEVE THAT THE LACK OF
MIXING IS KEEPING WIND GUSTS BELOW 50 KTS DESPITE THE FAVORABLE
SFC PRESSURE PATTERN AND STRONG WINDS JUST OFF THE SFC. WILL KEEP
THE HIGH WIND WARNING GOING THROUGH THE MORNING BUT CONDITIONS ARE
CURRENTLY LOOKING MARGINAL FOR WIDESPREAD HIGH WINDS OUTSIDE OF
ARLINGTON. THE SFC LOW CURRENTLY OVER NORTHERN WYOMING IS PROGGED
TO SHIFT EASTWARD INTO WESTERN SOUTH DAKOTA BY MIDDAY. THIS WILL
CAUSE LLVL FLOW TO GO MORE WESTERLY...BUT STILL EXPECT BREEZY-
TO-WINDY CONDITIONS TO CONTINUE ALONG AND WEST OF THE LARAMIE
RANGE WITH 700MB FLOW AT THE AFOREMENTIONED 30-40 KTS.
LOW CLOUDS AND FOG HAVE DEVELOPED OVER THE WESTERN NEBRASKA
PANHANDLE EARLY THIS MORNING. THE HRRR MODEL SHOWS LIFR CONDITIONS
PERSISTING THROUGH AROUND 15Z. SOME LOCATIONS ACROSS THE SOUTHERN
PANHANDLE HAVE REPORTED DENSE FOG. CURRENTLY HAVE AN SPS OUT TO
COVER THE DENSE FOG THREAT BUT MAY NEED TO CONSIDER AN ADVISORY IF
THE CONDITIONS PERSIST. WATER VAPOR IMAGERY SHOWS THE STRONG UPPER
LEVEL TROUGH CURRENTLY OVER THE WEST COAST WITH THE MOISTURE
STREAMING ACROSS WESTERN WY. THIS TROUGH WILL PROGRESS EASTWARD
OVER THE COURSE OF THE DAY WITH THE MOISTURE AND LIFT PRODUCING A
SLIGHT CHANCE OF SHOWERS OVER THE WESTERN ZONES BY AFTERNOON.
THE MAIN FORECAST CHALLENGE OVER THE SHORT TERM INVOLVES THE
POTENTIAL MAJOR WINTER STORM EVENT BEGINNING ON WEDNESDAY. THE
MODELS ARE IN AGREEMENT IN SHOWING THE LARGE SCALE TROUGH AXIS
BEING LOCATED OVER UTAH AND IDAHO ON WEDNESDAY AFTERNOON. A 125 KT
UPPER LEVEL JET IS SITUATED OVER WYOMING ON WEDNESDAY. A SW-NE
ORIENTED MIDLEVEL FRONTOGENESIS LINE DEVELOPS FROM RAWLINS TO
DOUGLAS BY MIDDAY WEDNESDAY. SNOW BECOMES LIKELY TO THE WEST OF THE
LARAMIE RANGE ON WEDNESDAY MORNING WITH 700MB TEMPS AROUND -4C. A
STRONG SHORTWAVE IN THE TROUGH IS FORECASTED TO MOVE OVER COLORADO
ON WEDNESDAY NIGHT. INCREASING LARGE SCALE LIFT AND UPPER LEVEL
DIVERGENCE WILL CAUSE WIDESPREAD SNOW TO DEVELOP MAINLY AFTER 00Z
THURS OVER THE PLAINS. IT IS THE 00Z-12Z PERIOD THAT SNOWFALL
RATES WILL BE HIGHEST IN SOUTHEAST WYOMING WITH EXCELLENT LARGE
SCALE UPWARD MOTION AND DEEP LAYERED SATURATION. THE SHORTWAVE
QUICKLY PROGRESSES EASTWARD INTO THE CENTRAL PLAINS ON THURS
MORNING WITH SNOWFALL RATES COMING DOWN SUBSTANTIALLY. THURS WILL
BE QUITE COLD FOR LATE OCTOBER WITH LLVL UPSLOPE AND 700MB TEMPS
AROUND -10C. WITH A LACK OF LARGE SCALE FORCING ON THURS...LIGHT
SNOW SHOWERS WILL LIKELY BE CONFINED TO THE MTNS AND FAVORED
UPSLOPE AREAS ALONG THE LARAMIE RANGE.
WITH REGARD TO WINTER WEATHER HIGHLIGHTS...DECIDED TO ISSUE A
WINTER STORM WATCH FOR AREAS ALONG THE LARAMIE RANGE AND THE
SIERRA MADRE AND SNOWY RANGES. HAVE THE WATCH CONTINUING THROUGH
THE 00Z FRI AS LIGHT SNOW WILL LIKELY CONTINUE THROUGH THURS
AFTN OVER THE HIGHER ELEVATIONS. FUTURE SHIFTS CAN DECIDE IF THE
HIGHLIGHTS SHOULD BE ENDED OVER LOWER ELEVATIONS AFTER THE
SNOWFALL RATES COME DOWN ON THURS MORNING AS THE MODELS ARE
SHOWING. SNOWFALL ACCUMULATIONS WILL LIKELY BE ON THE LOW END OF
WARNING CRITERIA WITH THIS EVENT. WINDS WILL NOT BE MUCH OF A
CONCERN WITH THIS SYSTEM...HOWEVER OCCASIONAL GUSTS TO 35 MPH WILL
BE POSSIBLE AS THE COLD FRONT MOVES ACROSS THE PLAINS ON WED
EVENING. MUCH WEAKER WINDS CWA-WIDE ON THURS AS THE SFC HIGH
PRESSURE SETTLES OVER THE PLAINS.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
LATEST MEDIUM RANGE MODEL OUTPUT OFFER FAIRLY SIMILAR SOLUTIONS
THROUGH THE WEEKEND WITH SOME DIVERGENCE NOTED EARLY NEXT WEEK.
INITIALLY...A TRAILING SHORTWAVE WILL ROUND THE BASE OF THE BROAD
TROUGH FROM NRN UTAH INTO COLORADO THURSDAY NIGHT.
MEANWHILE...UPSLOPE FLOW WILL PERSIST IN THE LLVLS PARTICULARLY FOR
LOCATIONS NEAREST THE LARAMIE RANGE. SO...WOULD EXPECT ANOTHER BOUT
OF LIGHT SNOW ON THURSDAY NIGHT ADDING ANOTHER INCH OR TWO TO THE
THE SNOWFALL TOTALS.
THE SHORTWAVE WILL ACCELERATE EAST OUT ONTO THE PLAINS FOR
FRIDAY...LEAVING NORTHWEST FLOW TO PREVAIL ACROSS THE CWFA. THERE
MAY BE SOME LIGHT SNOW OR FLURRIES CONTINUING MAINLY FOR OROGRAPHIC
AREAS ON FRIDAY MORNING...WITH A GRADUAL DRYING TREND DURING THE
AFTERNOON. TEMPERATURES WILL CONTINUE TO BE COLD ON FRIDAY WITH H7
TEMPERATURES REMAINING AROUND -10C. THIS WILL KEEP HIGH TEMPERATURES
IN THE 30S ACROSS THE AREA. FRANKLY WITH SNOW ON THE GROUND WOULD
NOT BE AT ALL SURPRISED TO ONLY SEE 20S AT SOME AREAS ON FRIDAY.
ON SATURDAY...THE LATEST GFS TRACKING ANOTHER SHORTWAVE INTO THE
AREA IN NORTHWEST FLOW. THE ECMWF/UKMET/GEM/GFES DO NOT SUPPORT SUCH
A SOLUTION...SO HAVE CONSIDER IT TO BE THE OUTLIER AND HAVE
DISCOUNTED. AS SUCH A DRY DAY IS IN STORE ON SATURDAY WITH
TEMPERATURES THAT WILL CLIMB INTO THE 30S AND 40S. WINDS WILL
INCREASE FOR AREAS ALONG AND WEST OF THE LARAMIE RANGE AS LLVL
GRADIENT TIGHTENS. SO EVEN THOUGH TEMPERATURES WILL BE SLIGHTLY
WARMER...THE WINDS WILL MAKE IT FEEL MUCH COOLER IN THESE AREAS.
NORTHWEST FLOW WILL CONTINUE ON SUNDAY. BUT THE ECMWF IS SHOWING THE
EARLY SIGNS OF ANTICYCLONIC FLOW DEVELOPING OVER THE AREA BY LATE
SUNDAY. COMPARATIVELY THE GFS MAINTAINS NORTHWEST FLOW OVR THE AREA
AS A RESULT OF A STRONGER TROUGH OVER WRN CANADA. THE GEM/UKMET
SOLUTIONS OVER A REASONABLE COMPROMISE BETWEEN THE GFS/ECMWF. IN ANY
CASE...EXPECT CONDITIONS TO REMAIN DRY WITH TEMPERATURES MODERATING
BACK INTO THE 50S AND 60S FOR THE SUNDAY THROUGH TUESDAY TIMEFRAME.
FIRE WEATHER...
A WINDY START TO THE DAY FOR AREAS WEST ALONG AND WEST OF THE
LARAMIE RANGE TODAY...AS GUSTS OF 40 TO 50 MPH HAVE BEEN COMMON.
THESE WINDS WILL CONTINUE THROUGH MUCH OF THE DAY BEFORE RELAXING
THIS EVENING AND OVERNIGHT. MEANWHILE...FOGGY CONDITIONS ACROSS THE
WESTERN PANHANDLE WILL PERSIST THROUGH MID/LATE MORNING BEFORE
LIFTING. ONE MORE WARM DAY IS IN STORE TODAY WITH HIGH TEMPERATURES
THAT WILL REACH THE 50S WEST OF THE LARAMIE RANGE AND 60S AND 70S
OUT ON THE EASTERN PLAINS. BIG CHANGES ARE ON THE WAY TOMORROW
HOWEVER...AS A COLD FRONT BEGINS TO PUSH THROUGH THE AREA.
PRECIPITATION WILL TRANSITION FROM RAIN TO SNOW THROUGH THE DAY AS
THE FRONT PROGRESSES SOUTH. PRECIPITATION WILL TURN TO ALL SNOW FOR
WEDNESDAY NIGHT AND THURSDAY. SIGNIFICANT ACCUMULATING SNOW IS
LOOKING INCREASINGLY POSSIBLE. MUCH COLDER AIR WILL FILTER IN FOR
THURSDAY AND FRIDAY AS WELL...WITH HIGHS ONLY CLIMBING INTO THE 20S
AND 30S.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM 6 AM WEDNESDAY TO 6 PM THURSDAY FOR
WYZ103-WYZ105-WYZ110-WYZ112-WYZ114.
WINTER STORM WATCH FROM 6 PM WEDNESDAY TO 6 PM THURSDAY FOR
WYZ106-WYZ115-WYZ116-WYZ117-WYZ118.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...FINCH
LONG TERM...HAHN