Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/22/12
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
858 AM PDT SAT OCT 20 2012
...RAINY AND BREEZY WEATHER SUNDAY NIGHT INTO MONDAY...
.DISCUSSION...AS OF 8:45 AM PDT SATURDAY...PLENTY OF CLOUDS STILL
AROUND THE CWA THIS MORNING -- IN FACT CURRENT SATELLITE IMAGE
LOOKS A LOT THIS WHAT WE WOULD SEE DURING THE SUMMER MONTHS.
HOWEVER SOME SPOTS ARE STARTING TO BREAK (INCLUDING HERE IN
MONTEREY WHERE THE SUN IS NOW OUT) SO MOST LOCATIONS SHOULD END UP
SEEING SOME SUNSHINE TODAY. NORTHERLY SURFACE GRADIENT OF 4 MB
(WITH WESTERLY PIECE OF 1.7 MB) ALSO SUGGESTS SUNSHINE BY
AFTERNOON. CURRENT HIGH TEMPERATURE FORECAST HAS ONLY A MINOR
RANGE WITH 60S TO LOW 70S AT THE COAST AND MOSTLY 70S INLAND.
MAIN STORY CONTINUES TO BE THE MAJOR CHANGE IN THE WEATHER AS A
STRONG STORM SYSTEM FOR THIS TIME OF THE YEAR CRASHES INTO THE
WEST COAST STARTING SUNDAY EVENING WITH THE MAIN IMPACT FOR US
SUNDAY NIGHT INTO MONDAY. LATEST SUITE OF MODELS ARE NOW IN AND
ALTHOUGH RAIN LOOKS LIKELY FOR ALL SPOTS THE VAST MAJORITY OF THE
ENERGY APPEARS TO STAY LOCATED NORTH OF SF BAY. JUST GOT OFF A
CALL WITH CNRFC AND CONFIDENCE IS FAIRLY HIGH WITH THE PLACEMENT
OF THE HIGHER QPF VALUES FOR THE NORTH BAY AND POINTS TO THE NORTH.
WITHOUT SOUNDING LIKE A BROKEN RECORD....TODAY IS A VERY GOOD DAY
TO MAKE SURE THAT ALL GUTTERS AND STORM DRAINS ARE CLEARED OUT.
12Z MODELS BRING THE HEAVIEST RAINFALL ACROSS SUNDAY NIGHT INTO
MONDAY MORNING AS THE COLD FRONT PUSHES ACROSS OUR CWA. GUSTY
WINDS CAN ALSO BE EXPECTED AT THIS TIME WITH 850 MB SPEEDS NEAR 40
KT (ALTHOUGH IT IS IMPORTANT TO NOTE THAT THIS IS A DECREASE OF
NEARLY 10 KT COMPARED TO PREVIOUS RUNS). SCATTERED SHOWERS ARE
EXPECTED TO CONTINUE AT LEAST INTO TUESDAY ALTHOUGH AMOUNTS ARE
ANTICIPATED TO BE LESS. WOULD NOT BE SURPRISED IF SOME PARTS OF
THE NORTH BAY PICK UP AROUND AN INCH AND A HALF BY TUESDAY MORNING
FROM THE ENTIRE EVENT.
.PREVIOUS DISCUSSION...CLOUDS COVER MOST OF THE DISTRICT EARLY
THIS MORNING EXCEPT FOR SOME OF THE HIGHER PEAKS. TEMPERATURES ARE
GENERALLY RUNNING IN THE 50S WHICH IS ABOUT 4-8 DEGREES COOLER
THAN YESTERDAY AT THIS TIME. EXPECT SLOW CLEARING THIS MORNING AS
ONSHORE WINDS WILL BE INCREASING THROUGH THE DAY. COMPARED TO
FRIDAY...HIGHS THIS AFTERNOON WILL ONCE AGAIN COOL A FEW DEGREES
WITH A STRONG SEA-BREEZE EXPECTED THIS AFTERNOON AS DEPICTED BY
THE NAM MODEL WITH AN INITIAL DRY BOUNDARY AND WIND SHIFT FORECAST
TO REACH THE COAST LATE THIS AFTERNOON. IN PARTICULAR THIS WILL
ALLOW WINDS TO PICK UP OVER THE OCEAN WITH GALE WARNINGS BEING
HOISTED. HEADS UP FOR FOLKS HEADING OUT ON THE WATER THIS WEEKEND.
INCOMING STORM IS NOW NOTED ON SATELLITE IMAGERY OUT NEAR 160 WEST
AND ASSOCIATED WITH STRONG JET STREAM ENERGY THAT WILL INTERACT
WITH UNSEASONABLY COLD AIR SPILLING OUT OF THE GULF OF ALASKA.
HIGH CLOUDS WILL BE NOTED EARLY SUNDAY MORNING AND INCREASE
THROUGH THE DAY. IF ANYTHING MODELS ARE TRENDING FASTER WITH THE
ARRIVAL OF THE INCOMING SYSTEM. CANT COMPLETELY RULE OUT A STRAY
SHOWER OR SPRINKLE OR TWO ACROSS THE BAY AREA AS EARLY AS SUNDAY
AFTERNOON. HOWEVER ANY RENEGADE SHOWERS WILL BE BRIEF AND SPOTTY
LATE IN THE DAY. THERE REMAINS BETTER MODEL CONSENSUS FOR LIGHT
RAIN OVERSPREADING THE BAY AREA AFTER 03Z MONDAY AND THEN
INCREASING IN INTENSITY IN THE PRE-DAWN HOURS OF MONDAY. THE MONDAY
MORNING COMMUTE WILL LIKELY BE UGLY WITH WET ROADS FOR THE ENTIRE
BAY AREA AND LIKELY DOWN TO THE MONTEREY BAY REGION. THE ACTUAL FRONTAL
PASSAGE LOOKS TO OCCUR SOMETIME BETWEEN 12-18Z MONDAY. DURING THIS
TIME FRAME A BRIEF WINDOW OF MODERATE RAINFALL WILL LIKELY OCCUR
WITH THE HEAVIEST RAINFALL IN THE NORTH BAY. IN ADDITION PRE-FRONTAL
WINDS FROM THE SOUTHEAST WILL SHIFT TO SW. LOCALIZED BUT FREQUENT
GUSTS IN THE 30-40 MPH RANGE WILL BE LIKELY. HISTORICALLY EARLY
SEASON FRONTAL PASSAGES SUCH AS THIS BRING DOWN WEAK OR DISEASED
TREES AND LIMBS WHICH CAN LEAD TO POWER OUTAGES AND OTHER HAZARDS.
ANY STEADY RAIN SHOULD TAPER TO SHOWERS BY MONDAY AFTERNOON AND
EVENING. UNSEASONABLY COLD AIR ALOFT WILL FILTER IN BEHIND THE
FRONT AND SHOWER CHANCES WILL CONTINUE INTO TUESDAY. THE COLD AIR
WITH THIS SYSTEM WILL ALSO BRING SNOW TO THE SIERRA AND IMPACT
ROADS UP THERE.
BY ALL ACCOUNTS THE INCOMING SYSTEM LOOKS FAIRLY FORMIDABLE AND
THE RAPID TRANSITION FROM DRY AND STABLE WEATHER TO WET WEATHER
WILL BE FAIRLY DRAMATIC. TODAY AND SUNDAY WILL OFFER THE BEST
CHANCE FOR ANY PRE-STORM PREPARATIONS SUCH AS CLEANING OF GUTTERS
AND CULVERTS OR TRIMMING OF WEAKENED TREE BRANCHES.
THE PATTERN FROM WEDS THROUGH FRIDAY REMAINS ACTIVE FOR LATE
OCTOBER BUT LATEST TRENDS SHOW THE STORM TRACK SHIFTING NORTH OF
INTERSTATE 80. HOWEVER SOME SHOWER OR LIGHT RAIN CHANCES WILL
LINGER ESPECIALLY FOR THE NORTH BAY THROUGH THE WEEK.
LOOKS LIKE THE RIDGE REBUILDS BY ABOUT NEXT FRIDAY WITH A DRYING
AND WARMING TREND BY NEXT WEEKEND. WILL FRESHEN UP THE SPECIAL
WEATHER STATEMENT FOR THE SUNDAY NIGHT/MONDAY SYSTEM.
&&
.AVIATION...AS OF 4:25 AM SATURDAY...VERY DIFFICULT FORECAST THIS
MORNING...AS MARINE LAYER CONTINUES TO DEEPEN AHEAD OF A STORM
SYSTEM. MODERATE ONSHORE FLOW OVERNIGHT ALLOWED STRATUS TO MOVE
WELL INLAND...IMPACTING ALL TERMINALS. MOST OF THE SHORT TERM
MODELS...SUCH AS THE NAM...WRF...AND HRRR ARE PESSIMISTIC...WITH
VFR CONDITIONS AFTER 20Z. OTHERWISE...MODERATE TO STRONG ONSHORE
WINDS WILL DEVELOP THIS AFTERNOON...WITH A POSSIBLE RETURN OF
STRATUS OVERNIGHT.
VICINITY OF KSFO....IFR CIGS ARE FORECAST TO LIFT TO MVFR BY
18Z...WITH VFR AFTER 20Z. LOW CONFIDENCE. MODERATE TO STRONG
ONSHORE WINDS THIS AFTERNOON...WITH POSSIBLE GUSTS NEAR 30 KT AT
KSFO BETWEEN 22Z TODAY AND 05Z SUNDAY.
KSFO BRIDGE APPROACH...APPROACH MAY BE IMPACTED THROUGH 21Z.
MONTEREY BAY AREA TERMINALS...IFR TO LIFR CIGS POSSIBLE THROUGH AT
LEAST 20Z. POSSIBLE ALL DAY EVENT AT KMRY. LOW CONFIDENCE.
&&
.MARINE...AS OF 4:30 AM PDT SATURDAY...SURFACE HIGH PRESSURE WILL
CONTINUE TO BUILD OVER THE EASTERN PACIFIC TODAY INTO SUNDAY. THIS
WILL RESULT IN MODERATE TO STRONG NORTHERLY WINDS OVER THE REGION.
WINDS WILL SIGNIFICANTLY INCREASE LATE THIS MORNING OVER THE
NORTHERN WATERS...WITH GUSTS TO 40 KT POSSIBLE THROUGH EARLY
SUNDAY MORNING. THESE STRONG WINDS WILL RESULT IN STEEP FRESH
SWELLS. WINDS WILL BEGIN TO SLOWLY SUBSIDE SUNDAY MORNING INTO
SUNDAY AFTERNOON.
BY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING...A STORM SYSTEM
WILL APPROACH THE REGION...RAPIDLY SWITCHING WINDS FROM THE NORTH
TO THE SOUTH. SOUTHERLY WINDS WITH GUSTS TO 30 KT WILL BE POSSIBLE
FOR A SHORT PERIOD OF TIME EARLY MONDAY.
MARINERS ARE ENCOURAGED TO CONTINUE TO MONITOR THE FORECAST
CLOSELY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 1 PM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 11 AM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 11 AM
GLW...PT ARENA TO PT REYES 0-10 NM FROM 11 AM
GLW...PT ARENA TO PIGEON PT 10-60 NM FROM 11 AM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...SF BAY FROM 1 PM
SCA...MRY BAY FROM 1 PM
&&
$$
PUBLIC FORECAST: BELL/RWW
AVIATION/MARINE: RILEY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
434 AM PDT SAT OCT 20 2012
...RAIN AND BREEZY WEATHER SUNDAY NIGHT INTO MONDAY...
.DISCUSSION...AS OF 4:17 AM PDT SATURDAY...CLOUDS COVER MOST OF
THE DISTRICT EARLY THIS MORNING EXCEPT FOR SOME OF THE HIGHER
PEAKS. TEMPERATURES ARE GENERALLY RUNNING IN THE 50S WHICH IS ABOUT
4-8 DEGREES COOLER THAN YESTERDAY AT THIS TIME. EXPECT SLOW
CLEARING THIS MORNING AS ONSHORE WINDS WILL BE INCREASING THROUGH
THE DAY. COMPARED TO FRIDAY...HIGHS THIS AFTERNOON WILL ONCE AGAIN
COOL A FEW DEGREES WITH A STRONG SEA-BREEZE EXPECTED THIS
AFTERNOON AS DEPICTED BY THE NAM MODEL WITH AN INITIAL DRY
BOUNDARY AND WIND SHIFT FORECAST TO REACH THE COAST LATE THIS
AFTERNOON. IN PARTICULAR THIS WILL ALLOW WINDS TO PICK UP OVER THE
OCEAN WITH GALE WARNINGS BEING HOISTED. HEADS UP FOR FOLKS HEADING
OUT ON THE WATER THIS WEEKEND.
INCOMING STORM IS NOW NOTED ON SATELLITE IMAGERY OUT NEAR 160 WEST
AND ASSOCIATED WITH STRONG JET STREAM ENERGY THAT WILL INTERACT
WITH UNSEASONABLY COLD AIR SPILLING OUT OF THE GULF OF ALASKA.
HIGH CLOUDS WILL BE NOTED EARLY SUNDAY MORNING AND INCREASE
THROUGH THE DAY. IF ANYTHING MODELS ARE TRENDING FASTER WITH THE
ARRIVAL OF THE INCOMING SYSTEM. CANT COMPLETELY RULE OUT A STRAY
SHOWER OR SPRINKLE OR TWO ACROSS THE BAY AREA AS EARLY AS SUNDAY
AFTERNOON. HOWEVER ANY RENEGADE SHOWERS WILL BE BRIEF AND SPOTTY
LATE IN THE DAY. THERE REMAINS BETTER MODEL CONSENSUS FOR LIGHT
RAIN OVERSPREADING THE BAY AREA AFTER 03Z MONDAY AND THEN
INCREASING IN INTENSITY IN THE PRE-DAWN HOURS OF MONDAY. THE MONDAY
MORNING COMMUTE WILL LIKELY BE UGLY WITH WET ROADS FOR THE ENTIRE
BAY AREA AND LIKELY DOWN TO THE MONTEREY BAY REGION. THE ACTUAL FRONTAL
PASSAGE LOOKS TO OCCUR SOMETIME BETWEEN 12-18Z MONDAY. DURING THIS
TIME FRAME A BRIEF WINDOW OF MODERATE RAINFALL WILL LIKELY OCCUR
WITH THE HEAVIEST RAINFALL IN THE NORTH BAY. IN ADDITION PRE-FRONTAL
WINDS FROM THE SOUTHEAST WILL SHIFT TO SW. LOCALIZED BUT FREQUENT
GUSTS IN THE 30-40 MPH RANGE WILL BE LIKELY. HISTORICALLY EARLY
SEASON FRONTAL PASSAGES SUCH AS THIS BRING DOWN WEAK OR DISEASED
TREES AND LIMBS WHICH CAN LEAD TO POWER OUTAGES AND OTHER HAZARDS.
ANY STEADY RAIN SHOULD TAPER TO SHOWERS BY MONDAY AFTERNOON AND
EVENING. UNSEASONABLY COLD AIR ALOFT WILL FILTER IN BEHIND THE
FRONT AND SHOWER CHANCES WILL CONTINUE INTO TUESDAY. THE COLD AIR
WITH THIS SYSTEM WILL ALSO BRING SNOW TO THE SIERRA AND IMPACT
ROADS UP THERE.
BY ALL ACCOUNTS THE INCOMING SYSTEM LOOKS FAIRLY FORMIDABLE AND
THE RAPID TRANSITION FROM DRY AND STABLE WEATHER TO WET WEATHER
WILL BE FAIRLY DRAMATIC. TODAY AND SUNDAY WILL OFFER THE BEST
CHANCE FOR ANY PRE-STORM PREPARATIONS SUCH AS CLEANING OF GUTTERS
AND CULVERTS OR TRIMMING OF WEAKENED TREE BRANCHES.
THE PATTERN FROM WEDS THROUGH FRIDAY REMAINS ACTIVE FOR LATE
OCTOBER BUT LATEST TRENDS SHOW THE STORM TRACK SHIFTING NORTH OF
INTERSTATE 80. HOWEVER SOME SHOWER OR LIGHT RAIN CHANCES WILL
LINGER ESPECIALLY FOR THE NORTH BAY THROUGH THE WEEK.
LOOKS LIKE THE RIDGE REBUILDS BY ABOUT NEXT FRIDAY WITH A DRYING
AND WARMING TREND BY NEXT WEEKEND. WILL FRESHEN UP THE SPECIAL
WEATHER STATEMENT FOR THE SUNDAY NIGHT/MONDAY SYSTEM.
&&
.AVIATION...AS OF 4:25 AM SATURDAY...VERY DIFFICULT FORECAST THIS
MORNING...AS MARINE LAYER CONTINUES TO DEEPEN AHEAD OF A STORM
SYSTEM. MODERATE ONSHORE FLOW OVERNIGHT ALLOWED STRATUS TO MOVE
WELL INLAND...IMPACTING ALL TERMINALS. MOST OF THE SHORT TERM
MODELS...SUCH AS THE NAM...WRF...AND HRRR ARE PESSIMISTIC...WITH
VFR CONDITIONS AFTER 20Z. OTHERWISE...MODERATE TO STRONG ONSHORE
WINDS WILL DEVELOP THIS AFTERNOON...WITH A POSSIBLE RETURN OF
STRATUS OVERNIGHT.
VICINITY OF KSFO....IFR CIGS ARE FORECAST TO LIFT TO MVFR BY
18Z...WITH VFR AFTER 20Z. LOW CONFIDENCE. MODERATE TO STRONG
ONSHORE WINDS THIS AFTERNOON...WITH POSSIBLE GUSTS NEAR 30 KT AT
KSFO BETWEEN 22Z TODAY AND 05Z SUNDAY.
KSFO BRIDGE APPROACH...APPROACH MAY BE IMPACTED THROUGH 21Z.
MONTEREY BAY AREA TERMINALS...IFR TO LIFR CIGS POSSIBLE THROUGH AT
LEAST 20Z. POSSIBLE ALL DAY EVENT AT KMRY. LOW CONFIDENCE.
&&
.MARINE...AS OF 4:30 AM PDT SATURDAY...SURFACE HIGH PRESSURE WILL
CONTINUE TO BUILD OVER THE EASTERN PACIFIC TODAY INTO SUNDAY. THIS
WILL RESULT IN MODERATE TO STRONG NORTHERLY WINDS OVER THE REGION.
WINDS WILL SIGNIFICANTLY INCREASE LATE THIS MORNING OVER THE
NORTHERN WATERS...WITH GUSTS TO 40 KT POSSIBLE THROUGH EARLY
SUNDAY MORNING. THESE STRONG WINDS WILL RESULT IN STEEP FRESH
SWELLS. WINDS WILL BEGIN TO SLOWLY SUBSIDE SUNDAY MORNING INTO
SUNDAY AFTERNOON.
BY LATE SUNDAY NIGHT INTO EARLY MONDAY MORNING...A STORM SYSTEM
WILL APPROACH THE REGION...RAPIDLY SWITCHING WINDS FROM THE NORTH
TO THE SOUTH. SOUTHERLY WINDS WITH GUSTS TO 30 KT WILL BE POSSIBLE
FOR A SHORT PERIOD OF TIME EARLY MONDAY.
MARINERS ARE ENCOURAGED TO CONTINUE TO MONITOR THE FORECAST
CLOSELY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 1 PM
SCA...PT ARENA TO PT REYES 0-10 NM UNTIL 11 AM
SCA...PT ARENA TO PIGEON PT 10-60 NM UNTIL 11 AM
GLW...PT ARENA TO PT REYES 0-10 NM FROM 11 AM
GLW...PT ARENA TO PIGEON PT 10-60 NM FROM 11 AM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 8 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 8 AM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 8 AM
SCA...SF BAY FROM 1 PM
SCA...MRY BAY FROM 1 PM
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: RILEY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
846 PM CDT SUN OCT 21 2012
.DISCUSSION...
ISSUED 846 PM CDT SUN OCT 21 2012
AN APPROACHING UPPER-LEVEL WAVE WILL SPREAD CLOUDS ACROSS CENTRAL
ILLINOIS OVER THE NEXT COUPLE OF HOURS...WITH OVERCAST CONDITIONS
EXPECTED ACROSS THE BOARD AFTER MIDNIGHT. MAIN QUESTION IN THE
SHORT-TERM WILL BE WHETHER ANY SHOWERS CAN DEVELOP ACROSS THE
AREA. LATEST RUN OF THE HRRR CONTINUES TO SHOW CONVECTION FORMING
OVER NORTHERN MISSOURI LATE TONIGHT...THEN LIFTING NORTHEASTWARD
TOWARD WEST-CENTRAL ILLINOIS BY DAWN. 18Z NAM WAS A BIT MORE
AGGRESSIVE IN SPREADING SHOWERS EASTWARD INTO ILLINOIS BETWEEN 09Z
AND 12Z. WITH 00Z KILX UPPER AIR SOUNDING SHOWING QUITE A BIT OF
DRY AIR IN PLACE ABOVE 850MB...WILL CONTINUE TO FAVOR THE SLOWER
HRRR. AS A RESULT...WILL ONLY MAINTAIN LOW CHANCE POPS FOR SHOWERS
ACROSS THE W/SW KILX CWA AFTER MIDNIGHT...WITH DRY CONDITIONS
PERSISTING ACROSS MOST OF THE AREA. HAVE ADJUSTED POPS AND SKY
COVER TO BETTER REFLECT CURRENT TRENDS. HAVE ALSO RAISED OVERNIGHT
LOW TEMPS INTO THE LOWER 60S ALONG/SOUTH OF I-70...WHERE SKIES
HAVE ALREADY BECOME CLOUDY. ZONE UPDATE WILL BE ISSUED SHORTLY.
BARNES
&&
.AVIATION...
ISSUED 646 PM CDT SUN OCT 21 2012
A WEAK SHORT-WAVE TROUGH CURRENTLY OVER KANSAS WILL LIFT
NORTHEASTWARD TOWARD THE GREAT LAKES OVER THE NEXT 24
HOURS...SPREADING CLOUDS AND PERHAPS A FEW SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. LATEST HRRR CONTINUES TO SUGGEST
CONVECTION DEVELOPING ALONG THE NOSE OF AN INCREASING LOW-LEVEL
JET AHEAD OF THIS FEATURE WILL REMAIN LARGELY WEST OF THE
MISSISSIPPI RIVER THROUGH 12Z. OTHER HIGH-RES MODELS SUCH AS THE
NAM TRY TO SPREAD AT LEAST ISOLATED CONVECTION INTO THE ILLINOIS
RIVER VALLEY BETWEEN 09Z AND 12Z. GIVEN INITIAL DRY AIRMASS IN
PLACE ACROSS THE AREA...WILL TREND TOWARD THE SLOWER HRRR. USING
SATELLITE TIMING TOOLS...VFR CEILINGS OF BETWEEN 3500 AND 4500FT
WILL SPREAD ACROSS CENTRAL ILLINOIS LATER THIS EVENING...ARRIVING
AT KSPI BY 03Z...THEN FURTHER NORTHEAST TO KCMI BY AROUND 06Z. AS
AIRMASS GRADUALLY MOISTENS AND UPPER WAVE TRACKS INTO IOWA...A
BAND OF SHOWERS WILL LIKELY DEVELOP WEST OF THE MISSISSIPPI LATE
TONIGHT...THEM LIFT N/NE INTO NORTHERN ILLINOIS MONDAY MORNING.
MODEL CONSENSUS KEEPS STRONGEST FORCING JUST W/NW OF CENTRAL
ILLINOIS...SO MOST WIDESPREAD PRECIP WILL LIKELY MISS THE KILX
TERMINALS. HAVE THEREFORE ONLY INCLUDED VCSH AFTER THE 14-16Z TIME
FRAME AT MOST SITES. THE EXCEPTION IS KPIA...WHERE HIGHER RAIN
CHANCES WARRANT A TEMPO GROUP FOR SHRA AND MVFR CEILINGS BETWEEN
15Z AND 18Z. WINDS WILL INITIALLY BE FROM THE S/SE AT 5 TO 10MPH
TONIGHT...THEN WILL INCREASE AND GUST TO AROUND 20MPH ON MONDAY.
BARNES
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT SUN OCT 21 2012
THE MUCH ABOVE NORMAL WARMTH WILL HIGHLIGHT MOST OF THIS
FORECAST...ALONG WITH PERIODIC RAIN CHANCES THROUGH THE WEEK. A
COLD FRONT WILL USHER IN A SIGNIFICANT AIRMASS CHANGE TO BELOW
NORMAL CONDITIONS FOR LATE NEXT WEEKEND AND INTO THE FOLLOWING
WEEK.
SHORT TERM...TONIGHT THROUGH WEDNESDAY.
AS THE LONG WAVE TROUGH CONTINUES TO SLIDE FARTHER EAST OF
ILLINOIS...MUCH WARMER AIR IS FLOWING NORTH INTO THE AREA AS UPPER
LEVEL RIDGING INCREASES UP THE MISSISSIPPI RIVER VALLEY. WARM
ADVECTION CLOUDS ARE ADVANCING STEADILY NORTHEASTWARD THROUGH
MISSOURI TOWARD SW ILLINOIS. THOSE CLOUDS WILL EVENTUALLY
OVERSPREAD MOST OF OUR COUNTIES BY MONDAY MORNING...AIDED BY AN
INTENSIFYING LOW LEVEL JET. A SURFACE LOW AND 500MB SHORTWAVE IN
KANSAS WILL MOVE NORTHEAST INTO NW MISSOURI/SW IOWA BY 12Z/7AM
MONDAY.
A WARM FRONT EXTENDING EAST OF THE LOW WILL APPROACH CLOSE TO OUR
SW COUNTIES DURING THAT TIME. AS A RESULT OF THAT APPROACHING
ENERGY AND ENHANCE LIFT...WE MAY SEE A FEW SHOWERS OR THUNDERSTORMS
LATE TONIGHT IN OUR W/SW AREA...MAINLY WEST OF PIA TO SPI.
THE PRIMARY FORCING SHOULD REMAIN WEST OF OUR COUNTIES UNTIL
DURING THE DAY ON MONDAY. THE SURFACE LOW WILL LIFT NORTH INTO
IOWA...AND WARM FRONTOGENESIS WILL REDEFINE ACROSS NORTHERN
ILLINOIS BY MONDAY NIGHT. DURING THAT TIME A STEADY STREAM OF
MOISTURE WILL FLOW INTO OUR COUNTIES...EXPANDING CHANCES OF
SHOWERS AND STORMS FARTHER EASTWARD TO INCLUDE MOST OF OUR
COUNTIES NORTH OF I-70. THAT SAME COVERAGE SHOULD CONTINUE INTO
MONDAY NIGHT BEFORE DIMINISHING CHANCES ON TUESDAY AS THE WARM
FRONT LIFTS FARTHER NORTH AWAY FROM C IL. MARGINAL INSTABILITY AND
SHEAR PARAMETERS FROM LATE TONIGHT THROUGH MONDAY NIGHT COULD
ALLOW FOR A FEW STORMS TO PRODUCE SOME HAIL AND GUSTY WINDS...BUT
SEVERE WEATHER DOES NOT APPEAR LIKELY AT THIS TIME.
WE KEPT SLIGHT CHANCE POPS ACROSS ALL OF C IL FOR TUESDAY...AS WE
REMAIN IN AN UNSTABLE MOIST AIRMASS IN THE WARM SECTOR. THE
REMNANTS OF THE TROPICAL SYSTEM OFF THE BAJA OF CALIFORNIA WILL
MOVE ACROSS SOUTHERN IL ON TUESDAY AS WELL...HELPING TO PROVIDE
SOME DIFFUSE LIFT ACROSS THE AREA.
BY WEDNESDAY...WE SHOULD SEE DRY CONDITIONS RETURN AS SHORTWAVE
ENERGY AND FORCING FOR PRECIP REMAINS WEST AND NORTH OF C IL.
ADDITIONAL SUNSHINE ON WEDNESDAY WILL HELP BOOST HIGH TEMPS INTO
THE LOW 80S IN OUR SW COUNTIES...WITH MID TO UPPER 70S ELSEWHERE.
LONG TERM...THURSDAY THROUGH SUNDAY.
AN APPROACHING COLD FRONT FOR LATE WEEK HAS BEEN SLOWED DOWN BY
THE MODELS WITH EACH OF THE LAST 3 MODEL CYCLES. THAT WOULD HELP
BOOST THURSDAY HIGH TEMPS WELL ABOVE NORMAL FOR THE LAST TIME THIS
WEEK...AND KEEP PRECIP CHANCES HELD OFF UNTIL THURSDAY AFTERNOON
AT THE EARLIEST...AND MOST LIKELY UNTIL THURSDAY NIGHT. WE BEGAN
TO SHOW THAT TIMING TREND BY RAISING HIGH TEMPS IN THE SE HALF OF
OUR COUNTIES ON THURS...AND PUSH BACK CHANCE POPS TO THUR
AFTERNOON AND MAINLY NW OF THE IL RIVER.
AS THE FRONT MOVES INTO SOUTHEAST IL FRIDAY NIGHT...A SECONDARY
WAVE IS FORECAST TO QUICKLY MOVE OUT OF THE PLAINS AND UP ACROSS
ILLINOIS FRI NIGHT AND SATURDAY. TO REFLECT THAT CHANGE IN THE
EXTENDED FORECAST...WE INCREASED POPS FOR RAIN SHOWERS FRIDAY
NIGHT AND SATURDAY. BY SUNDAY...AND MUCH COOLER AIR IS EXPECTED TO
ADVANCE INTO ILLINOIS...STARTING AND EXTENDED PERIOD OF BELOW
NORMAL TEMPS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
646 PM CDT SUN OCT 21 2012
.DISCUSSION...
ISSUED 300 PM CDT SUN OCT 21 2012
THE MUCH ABOVE NORMAL WARMTH WILL HIGHLIGHT MOST OF THIS
FORECAST...ALONG WITH PERIODIC RAIN CHANCES THROUGH THE WEEK. A
COLD FRONT WILL USHER IN A SIGNIFICANT AIRMASS CHANGE TO BELOW
NORMAL CONDITIONS FOR LATE NEXT WEEKEND AND INTO THE FOLLOWING
WEEK.
SHORT TERM...TONIGHT THROUGH WEDNESDAY.
AS THE LONG WAVE TROUGH CONTINUES TO SLIDE FARTHER EAST OF
ILLINOIS...MUCH WARMER AIR IS FLOWING NORTH INTO THE AREA AS UPPER
LEVEL RIDGING INCREASES UP THE MISSISSIPPI RIVER VALLEY. WARM
ADVECTION CLOUDS ARE ADVANCING STEADILY NORTHEASTWARD THROUGH
MISSOURI TOWARD SW ILLINOIS. THOSE CLOUDS WILL EVENTUALLY
OVERSPREAD MOST OF OUR COUNTIES BY MONDAY MORNING...AIDED BY AN
INTENSIFYING LOW LEVEL JET. A SURFACE LOW AND 500MB SHORTWAVE IN
KANSAS WILL MOVE NORTHEAST INTO NW MISSOURI/SW IOWA BY 12Z/7AM
MONDAY.
A WARM FRONT EXTENDING EAST OF THE LOW WILL APPROACH CLOSE TO OUR
SW COUNTIES DURING THAT TIME. AS A RESULT OF THAT APPROACHING
ENERGY AND ENHANCE LIFT...WE MAY SEE A FEW SHOWERS OR THUNDERSTORMS
LATE TONIGHT IN OUR W/SW AREA...MAINLY WEST OF PIA TO SPI.
THE PRIMARY FORCING SHOULD REMAIN WEST OF OUR COUNTIES UNTIL
DURING THE DAY ON MONDAY. THE SURFACE LOW WILL LIFT NORTH INTO
IOWA...AND WARM FRONTOGENESIS WILL REDEFINE ACROSS NORTHERN
ILLINOIS BY MONDAY NIGHT. DURING THAT TIME A STEADY STREAM OF
MOISTURE WILL FLOW INTO OUR COUNTIES...EXPANDING CHANCES OF
SHOWERS AND STORMS FARTHER EASTWARD TO INCLUDE MOST OF OUR
COUNTIES NORTH OF I-70. THAT SAME COVERAGE SHOULD CONTINUE INTO
MONDAY NIGHT BEFORE DIMINISHING CHANCES ON TUESDAY AS THE WARM
FRONT LIFTS FARTHER NORTH AWAY FROM C IL. MARGINAL INSTABILITY AND
SHEAR PARAMETERS FROM LATE TONIGHT THROUGH MONDAY NIGHT COULD
ALLOW FOR A FEW STORMS TO PRODUCE SOME HAIL AND GUSTY WINDS...BUT
SEVERE WEATHER DOES NOT APPEAR LIKELY AT THIS TIME.
WE KEPT SLIGHT CHANCE POPS ACROSS ALL OF C IL FOR TUESDAY...AS WE
REMAIN IN AN UNSTABLE MOIST AIRMASS IN THE WARM SECTOR. THE
REMNANTS OF THE TROPICAL SYSTEM OFF THE BAJA OF CALIFORNIA WILL
MOVE ACROSS SOUTHERN IL ON TUESDAY AS WELL...HELPING TO PROVIDE
SOME DIFFUSE LIFT ACROSS THE AREA.
BY WEDNESDAY...WE SHOULD SEE DRY CONDITIONS RETURN AS SHORTWAVE
ENERGY AND FORCING FOR PRECIP REMAINS WEST AND NORTH OF C IL.
ADDITIONAL SUNSHINE ON WEDNESDAY WILL HELP BOOST HIGH TEMPS INTO
THE LOW 80S IN OUR SW COUNTIES...WITH MID TO UPPER 70S ELSEWHERE.
LONG TERM...THURSDAY THROUGH SUNDAY.
AN APPROACHING COLD FRONT FOR LATE WEEK HAS BEEN SLOWED DOWN BY
THE MODELS WITH EACH OF THE LAST 3 MODEL CYCLES. THAT WOULD HELP
BOOST THURSDAY HIGH TEMPS WELL ABOVE NORMAL FOR THE LAST TIME THIS
WEEK...AND KEEP PRECIP CHANCES HELD OFF UNTIL THURSDAY AFTERNOON
AT THE EARLIEST...AND MOST LIKELY UNTIL THURSDAY NIGHT. WE BEGAN
TO SHOW THAT TIMING TREND BY RAISING HIGH TEMPS IN THE SE HALF OF
OUR COUNTIES ON THURS...AND PUSH BACK CHANCE POPS TO THUR
AFTERNOON AND MAINLY NW OF THE IL RIVER.
AS THE FRONT MOVES INTO SOUTHEAST IL FRIDAY NIGHT...A SECONDARY
WAVE IS FORECAST TO QUICKLY MOVE OUT OF THE PLAINS AND UP ACROSS
ILLINOIS FRI NIGHT AND SATURDAY. TO REFLECT THAT CHANGE IN THE
EXTENDED FORECAST...WE INCREASED POPS FOR RAIN SHOWERS FRIDAY
NIGHT AND SATURDAY. BY SUNDAY...AND MUCH COOLER AIR IS EXPECTED TO
ADVANCE INTO ILLINOIS...STARTING AND EXTENDED PERIOD OF BELOW
NORMAL TEMPS.
&&
.AVIATION...
ISSUED 646 PM CDT SUN OCT 21 2012
A WEAK SHORT-WAVE TROUGH CURRENTLY OVER KANSAS WILL LIFT
NORTHEASTWARD TOWARD THE GREAT LAKES OVER THE NEXT 24
HOURS...SPREADING CLOUDS AND PERHAPS A FEW SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. LATEST HRRR CONTINUES TO SUGGEST
CONVECTION DEVELOPING ALONG THE NOSE OF AN INCREASING LOW-LEVEL
JET AHEAD OF THIS FEATURE WILL REMAIN LARGELY WEST OF THE
MISSISSIPPI RIVER THROUGH 12Z. OTHER HIGH-RES MODELS SUCH AS THE
NAM TRY TO SPREAD AT LEAST ISOLATED CONVECTION INTO THE ILLINOIS
RIVER VALLEY BETWEEN 09Z AND 12Z. GIVEN INITIAL DRY AIRMASS IN
PLACE ACROSS THE AREA...WILL TREND TOWARD THE SLOWER HRRR. USING
SATELLITE TIMING TOOLS...VFR CEILINGS OF BETWEEN 3500 AND 4500FT
WILL SPREAD ACROSS CENTRAL ILLINOIS LATER THIS EVENING...ARRIVING
AT KSPI BY 03Z...THEN FURTHER NORTHEAST TO KCMI BY AROUND 06Z. AS
AIRMASS GRADUALLY MOISTENS AND UPPER WAVE TRACKS INTO IOWA...A
BAND OF SHOWERS WILL LIKELY DEVELOP WEST OF THE MISSISSIPPI LATE
TONIGHT...THEM LIFT N/NE INTO NORTHERN ILLINOIS MONDAY MORNING.
MODEL CONSENSUS KEEPS STRONGEST FORCING JUST W/NW OF CENTRAL
ILLINOIS...SO MOST WIDESPREAD PRECIP WILL LIKELY MISS THE KILX
TERMINALS. HAVE THEREFORE ONLY INCLUDED VCSH AFTER THE 14-16Z TIME
FRAME AT MOST SITES. THE EXCEPTION IS KPIA...WHERE HIGHER RAIN
CHANCES WARRANT A TEMPO GROUP FOR SHRA AND MVFR CEILINGS BETWEEN
15Z AND 18Z. WINDS WILL INITIALLY BE FROM THE S/SE AT 5 TO 10MPH
TONIGHT...THEN WILL INCREASE AND GUST TO AROUND 20MPH ON MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1155 PM CDT FRI OCT 19 2012
.DISCUSSION...
ISSUED 855 PM CDT FRI OCT 19 2012
UPDATED THE FORECAST THIS EVENING TO INCREASE CHANCE OF SHOWERS
FROM LINCOLN NORTHEAST AND ALSO ADDED PATCHY FOG LATE TONIGHT NORTH
OF LINCOLN WITH SOME DECREASING LOW CLOUDS LATE. COOLED LOWS
CLOSER TO 40F OVER THE IL RIVER VALLEY WITH 40 TO 45F MOST REST
OF CENTRAL AND SE IL. WEST WINDS OF 8 TO 16 MPH THIS EVENING
DIMINISHING TO 5 TO 10 MPH OVERNIGHT. LOW CLOUDS BLANKET CENTRAL
AND SE IL THIS EVENING.
STRONG 538 DM 500 MB LOW OVER SOUTHERN LAKE MI HAS A FAIRLY STRONG
SHORT WAVE OVER NW IL PIVOTING SE INTO CENTRAL IL DURING MID EVENING
WITH ONE MORE BATCH OF SHOWERS AFFECTING AREAS FROM LINCOLN NE
UNTIL MIDNIGHT. POCKETS OF HEAVIER RAIN NE OF I-74 AND HAD A
REPORT OF PEA SIZE GRAPEL (SOFT HAIL) AT HOOPESTON AT 555 PM. 1001
MB SURFACE LOW WAS OVER SE LAKE MICHIGAN AND GRADUALLY WEAKENING
TODAY SINCE LOW PRESSURE SYSTEM IS NEARLY VERTICALLY STACKED. COOL
TEMPS CURRENTLY IN THE UPPER 40S AND LOWER 50S WITH WSW WINDS 8 TO
16 MPH AND A FEW GUSTS NEAR 20 MPH.
THE HRRR MODEL HANDLED QPF FIELDS THE BEST AND USED IT FOR THE
FORECAST UPDATE THIS EVENING WITH LIKELY CHANCES OF SHOWERS OVER
AREAS NE OF LINCOLN UNTIL MIDNIGHT. COULD BE A FEW LINGERING LIGHT
RAIN SHOWERS OR DRIZZLE EARLY OVERNIGHT FROM LINCOLN EAST. A LARGE
BREAK IN THE LOW CLOUDS OVER THE UPPER MS VALLEY OF NE
IA...EASTERN MN AND WESTERN WI TO TRACK SSE INTO THE IL RIVER
VALLEY LATER TONIGHT SO DECREASED CLOUDS THERE TO BECOME PARTLY
CLOUDY LATE AND ADDED PATCHY FOG LATE TONIGHT UNTIL MID MORNING SAT
NORTH OF LINCOLN. MODELS TAKE LOW PRESSURE JUST EAST OF SE PARTS
OF LOWER MI BY SUNRISE AND INTO SE ONTARIO BY 18Z/SAT. SO SHOWERS
TO DIMINISH BY EARLY OVERNIGHT WITH LOW CLOUDS DECREASE FROM NW TO
SE LATER TONIGHT AND SAT MORNING. LOWS MOSTLY 40 TO 45F...CLOSER
TO 40F OVER THE IL RIVER VALLEY WHERE SOME DECREASING CLOUDS
EXPECTED LATER.
07
&&
.AVIATION...
ISSUED 1155 PM CDT FRI OCT 19 2012
MVFR TO IFR CEILINGS WILL PREVAIL ACROSS THE CENTRAL IL AIRPORTS
DURING PART OF OVERNIGHT. A LINGERING BAND OF SHOWERS IS STILL
AFFECTING BMI AND ESPECIALLY CMI NEXT HOUR OR TWO WITH VSBYS
REDUCED TO MVFR AT TIMES WITH SHOWERS. MOST OF THESE SHOWERS
SHOULD EXIT SE INTO CENTRAL INDIANA BY 07Z/2 AM AS SHORT WAVE EXITS
SE FROM EAST CENTRAL IL INTO THE CENTRAL OHIO VALLEY DURING
OVERNIGHT. STRONG 539 DM 500 MB LOW AND CORRELATING 1002 SURFACE
LOW WAS OVER SOUTH CENTRAL/SW LOWER MI AND TO CONTINUE TO SLOWLY
WEAKEN AS IT LIFTS NE INTO SOUTHEAST ONTARIO SAT. FOG DEVELOPMENT A
CONCERN ESPECIALLY AT NORTHERN AIRPORTS OF PIA AND BMI LATER
TONIGHT AFTER 09Z UNTIL MID MORNING SAT AS A LARGE CLEARING AREA
OF THE LOW CLOUDS WAS SHIFTING SSE FROM THE UPPER MS VALLEY
ALREADY INTO NORTHERN IL LATE THIS EVENING. LOWERED VSBYS TO
BETWEEN 1/2 AND 1 MILE LATER TONIGHT AT PIA AND BMI WHILE VSBYS
SHOULD BE 1-3 MILES ALONG I-72 AIRPORTS WHERE LESS CLEARING EXPECTED
FURTHER SOUTH. REMAINING LOW CLOUDS TO ELEVATE TO VFR AND SCATTER
OUT ACROSS AREA LATER SAT MORNING WITH FAIR SKIES EXPECTED BY SAT
EVENING. WEST WINDS 7-11 KTS TO TURN WSW AT 5-10 KTS SAT AND THEN
SSE NEAR 5 KTS BY SUNSET SAT AS WEAK HIGH PRESSURE RIDGES MOVES
INTO THE MID MS AND OHIO VALLEYS.
07
&&
.PREV DISCUSSION...
ISSUED 254 PM CDT FRI OCT 19 2012
THE CHILLY CUT-OFF LOW WILL FINALLY MAKE AN EXIT TO THE EAST BY
SATURDAY MORNING...BRINGING AN END TO THIS ROUND OF COLD
RAIN/DRIZZLE TOWARD MIDNIGHT TONIGHT. CLOUDS WILL BE TOUGH TO
CLEAR OUT...BUT SUNSHINE SHOULD DEVELOP ON SATURDAY...HELPING TO
JUMP START OUR WARMING TREND. AN EXTENDED PERIOD OF ABOVE NORMAL
TEMPS WILL HIGHLIGHT THE EXTENDED FORECAST FROM SUNDAY THROUGH
THURSDAY. A LATE WEEK COLD FRONT WILL BRING NUMBERS BACK TOWARD OR
BELOW NORMAL FOR FRIDAY AND INTO NEXT WEEKEND. RAIN CHANCES WILL
BE FOCUSED FROM MONDAY THROUGH TUES WITH STRONG WARM ADVECTION AND
A NEARBY LOW PRESSURE/FRONTAL SYSTEM...AND AGAIN WITH THE
THURS/THUR NIGHT COLD FRONT.
SHORT TERM...TONIGHT THROUGH TUESDAY.
THE CHILLY AIRMASS WITH 850MB TEMPS AROUND -1C OVERHEAD IS HELPING
PRODUCE FAVORABLE CONDITIONS FOR SHOWERY PRECIP. THE HEAVIER
SHOWERS ARE BEING DRIVEN BY 500MB SHORTWAVES...THE NEXT OF WHICH
IS APPROACHING OUR NW COUNTIES FROM IOWA. THAT WAVE WILL KEEP
SHOWER CHANCES THROUGH THE EVENING ACROSS ALL OF C/SE IL. AS
MIXING DIMINISHES AFTER SUNSET...STRATUS AND DRIZZLE MAY BECOME
MORE PROMINENT. THE BULK OF THE PRECIP SHOULD BE DONE BY
MIDNIGHT...BUT CANT RULE OUT SOME LINGERING DRIZZLE AFTER MIDNIGHT
ACROSS THE NORTHEAST. A BLANKET OF LOW CLOUDS WILL REMAIN THROUGH
SATURDAY MORNING.
CLEARING WILL BEGIN SATURDAY MORNING WITH THE HEATING OF THE DAY
AND MIXING OF DRY AIR FROM JUST ABOVE THE CLOUD LAYER. INCREASING
SUNSHINE BY AFTERNOON WILL HELP PUSH TEMPS ABOUT 10 DEG F ABOVE
TODAY/S READINGS...WITH HIGHS IN THE LOW 60S.
MORE SIGNIFICANT WARMING IS ON TAP FOR SUNDAY...WITH PLENTY OF
SUNSHINE. HIGHS SHOULD TOP OUT ANOTHER 10-13F ABOVE
SATURDAY...WITH READINGS IN THE LOW TO MID 70S. HOWEVER...THE
STRONG MID LEVEL WARM ADVECTION WILL ALSO BE ACCOMPANIED BY STRONG
MOISTURE FLUX AS WELL. SURFACE DEWPOINTS WILL LIKEWISE CLIMB INTO
THE LOWER 60S...AIDING IN POSSIBLE SHOWERS AND THUNDERSTORMS
SUNDAY NIGHT.
SHOWER/STORM DEVELOPMENT WILL BE ENHANCED BY A SURFACE LOW MOVING
OUT OF THE PLAINS UP THROUGH IOWA BY SUNDAY NIGHT AND MONDAY
MORNING. INSTABILITY PARAMS SUPPORT THUNDERSTORM DEVELOPMENT...
ESPECIALLY DUE TO THE RELATIVELY HIGH SURFACE DEWPOINTS
ACCOMPANIED WITH FAVORABLE WIND SHEAR.
THE PRECIP CHANCES WILL BE SUSTAINED INTO TUESDAY AS THE REMNANTS
OF A TROPICAL SYSTEM /CURRENTLY OFF OF THE BAJA OF CALIFORNIA/
TRAIL INTO OUR AREA QUICKLY ON THE HEELS OF THE INITIAL LOW
PRESSURE SYSTEM.
LONG TERM...WEDNESDAY THROUGH FRIDAY.
THE MAIN EXTENDED FORECAST ISSUE WILL BE TIMING OF THE COLD FRONT
FOR EITHER THURSDAY /ECMWF & CANADIAN GEM/ OR THURSDAY NIGHT
/GFS/. AHEAD OF THE FRONT...THERE IS GOOD AGREEMENT THAT WED WILL
BE A DRY AND WARM DAY...WITH HIGHS POSSIBLY THE WARMEST OF THE
NEXT WEEK. SOME UPPER 70S IN OUR SW AREA WITH AT LEAST MID 70S ALL
ACROSS OUR AREA. SOME QUESTION MARKS REMAIN FOR THURSDAY
HIGHS...DEPENDING IF PRECIP RETURNS EARLY OR LATE THURSDAY. WE
WENT WITH THE PREMISE THAT EVEN WITH REDUCED SUNSHINE...ENOUGH
BURN-THROUGH HEATING SHOULD PUSH HIGHS INTO THE LOWER 70S.
THE PASSAGE OF THE COLD FRONT WILL BRING AN AIRMASS CHANGE FOR
FRIDAY AND THROUGH NEXT WEEKEND. TEMPS WILL LIKELY DIP BELOW
NORMAL FOR THE WEEKEND AND POSSIBLY INTO EARLY NEXT WEEK AS A DEEP
TROUGH BECOME ESTABLISHED IN THE MIDWEST ONCE AGAIN.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1129 PM CDT FRI OCT 19 2012
.AVIATION...
A CHALLENGING AVIATION FORECAST IS IN STORE FOR THE NEXT 10
HOURS...AS HIGH PRESSURE MOVES IN...CLEARING SKIES...BUT ALSO
ALLOWING FOR WIDESPREAD IFR/LIFR CONDITIONS TO DEVELOP. IT NOW
APPEARS THAT MINIMUM CONDITIONS ARE LIKELY AT MLI/CID/DBQ THROUGH
13Z...POSSIBLY 14Z. 1/4MI VISIBILITY AND VV001/BKN003 CONDITIONS
WILL BE COMMON THROUGH 13Z. AFTER SUNRISE...OR AFT 13Z/20...A
PERIOD OF VFR CLEAR/UNLIMITED WEATHER IS FORECAST FROM THE HIGH PRESSURE.
ERVIN
&&
.PREV DISCUSSION... /ISSUED 258 PM CDT FRI OCT 19 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS THE UPPER LOW OVER WISCONSIN WITH NUMEROUS
TROFS FROM THE OHIO VALLEY BACK INTO THE PLAINS AND UPPER MIDWEST.
SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOWS THE INITIAL
SUBSIDENCE HAS FILLED BACK IN WITH DIURNAL CLOUDS. A VORT MAX
ROTATING SOUTHEAST OUT OF MINNESOTA IS HELPING TO GENERATE NEW
SHOWERS/SPRINKLES.
18Z SFC ANALYSIS HAS A LOW OVER SOUTHERN LAKE MICHIGAN WEST OF
KBIV. NUMEROUS TROFS RAN FROM THE LOW FROM THE LOWER OHIO VALLEY
BACK UP THROUGH WISCONSIN AND MINNESOTA. DEW POINTS WERE IN THE
30S AND 40S ACROSS THE MIDWEST.
SHORT TERM...LATE THIS AFTERNOON THROUGH SATURDAY...
THE VORT MAX HELPING TO GENERATE THE SHRA ACTIVITY ACROSS THE CWFA
IS FURTHER TO THE NORTH/EAST THAN WHAT THE RAP WAS SUGGESTING
EARLIER TODAY. BASED ON THE CURRENT AND EXTRAPOLATED POSITION OF
THE SHRA ACTIVITY...THERE SHOULD BE AN AREA OF CONCENTRATED
SHOWERS BETWEEN KDBQ/KALO TO THE SOUTHEAST LATE THIS AFTERNOON.
SAID ACTIVITY WILL CONTINUE INTO THE EARLY EVENING FROM NORTHEAST
OF KIOW DOWN TOWARDS KGBG BEFORE DISSIPATING LATER THIS EVENING.
AROUND THIS BAND OF CONCENTRATED SHRA ACTIVITY ISOLATED TO LOW END
SCATTERED DIURNAL SHRA WILL BE SEEN THAT DISSIPATE SHORTLY AFTER
SUNSET.
BASED ON THE LUMPY NATURE OF THE CLOUDS ON SATELLITE...SUBSIDENCE
AND THE SETTING SUN WILL RESULT IN A CLEARING POCKET THAT DEVELOPS
ACROSS MN AND WESTERN WISCONSIN THAT SHOULD BEGIN ROTATING SOUTH
AND THEN SOUTHEAST ACROSS THE CWFA BY LATE EVENING WITH PARTIAL
CLEARING CONTINUING OVERNIGHT. WINDS WILL DIMINISH BUT NOT AS MUCH
AS LAST NIGHT. HOWEVER...IN SHELTERED AREAS AND SOME RIVER VALLEYS
THERE IS A POTENTIAL FOR PATCHY FOG TO DEVELOP LATE TONIGHT.
IF FOG DEVELOPS LATE TONIGHT IT WILL LINGER INTO EARLY SATURDAY
MORNING BEFORE BURNING OFF.
SATURDAY WILL BE A MUCH NICER DAY WITH SUNSHINE...POSSIBLY
FILTERED...WITH TEMPERATURES CLOSE TO NORMAL. 08
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
FLOW PATTERN ALOFT WILL TRANSITION TO SOUTHWESTERLY FLOW BY EARLY
IN THE WEEK. HEIGHT RISES... GOOD LOW LEVEL WARM ADVECTION AND
ABUNDANT SUNSHINE SHOULD COMBINE TO BRING ABOUT A NICE BOOST IN
TEMPS ON SUNDAY... WITH HIGHS MOSTLY IN THE UPPER 60S TO LOWER 70S
ON GUSTY S/SE WINDS.
SUN NGT THROUGH MON WILL BRING THE FIRST OF SEVERAL RAIN CHANCES
THROUGHOUT THE EXTENDED... AS 30+ KT LOW LEVEL JET AND ATTENDANT
MOISTURE TRANSPORT AND CONVERGENCE AIMED OVER THE REGION BY LATE SUN
EVE INTO MON AM AHEAD OF AN UPPER LEVEL DISTURBANCE LIFTING OUT
OF THE CENTRAL PLAINS. ISOLD/SCTD ELEVATED STORMS SEEM REASONABLE
WITH BOTH NAM AND GFS MODELS ADVECTING STEEP PLUME OF MID LEVEL
LAPSE RATES IN EXCESS OF 7 C/KM IN 700-500 MB LAYER BY 12Z MON. IN
ADDITION... CANT RULE OUT SEEING SOME FOG AND DRIZZLE WITH SUCH
STRONG LOW LEVEL MOISTURE TRANSPORT WITH SFC DEWPTS CLIMBING THROUGH
THE 50S INTO 60S. ALSO... EXPECTING NON DIURNAL TEMP TREND WITH
TEMPS STEADY TO RISING OVRNGT SUN NGT. RAIN CHANCES WILL PERSIST
MON NGT INTO TUE WITH SUGGESTIONS OF ADDITIONAL UPPER LEVEL ENERGY
LIFTING OUT OF THE PLAINS AHEAD OF WESTERN CONUS TROUGH.
OUR REGION WILL CONTINUE TO RESIDE IN SOUTHWESTERLY FLOW ALOFT THROUGH
AT LEAST MIDWEEK WITH BROAD... DEEP TROUGH CENTERED OFF THE PACIFIC
NORTHWEST COAST. THIS WILL RESULT IN CONTINUATION OF ABOVE TO MUCH
ABOVE NORMAL TEMPS WHILE STAYING UNSETTLED... ALTHOUGH SUGGESTION OF
LOWER RISK OF PCPN TUE INTO WED WITH MAIN FRONTAL ZONE LOCATED TO
OUR NORTH/WEST. ANTICIPATE FLOW PATTERN ALOFT TO FLATTEN OR TRANSITION
TO SEMI-ZONAL LATE WEEK AS MORE SUBSTANTIAL ENERGY EJECTS FROM
WESTERN TROUGH. THIS WILL SEND THE BOUNDARY BACK THROUGH AS COLD
FRONT ACCOMPANIED BY SHOWERS AND STORMS WED NGT THROUGH THU BASED ON
THE RECENT MODEL TRENDS OR DPROG/DT OF UKMET... ECMWF AND GFS.
MOST AREAS LIKELY TO SEE 0.25 TO 0.75 INCH OF RAIN WITH AREAS OF 1+
INCHES BETWEEN THE TWO MAIN PCPN WINDOWS OF SUN NGT-MON NGT AND WED NGT-
THU NGT. MCCLURE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
606 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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 546 PM MDT SUN OCT 21 2012
MODELS STILL INDICATING THAT STRATUS DECK WILL DEVELOP AROUND THE
06-08Z TIMEFRAME AT BOTH TERMINALS. HRRR BRINGS IFR STRATUS INTO KGLD
AROUND 10Z...SO THERE IS STILL SOME DISAGREEMENT IN TIMING BUT
WILL ADJUST AT NEXT ISSUANCE IF NECESSARY. DEWPOINTS HAVE ALREADY
INCREASED DRAMATICALLY ACROSS NORTH CENTRAL KANSAS WITH EASTERLY
SURFACE WINDS DUE TO SURFACE OVER WEST CENTRAL KANSAS. STRATUS
DESK WILL BEGIN TO DISSIPATE BY MID MORNING AT BOTH TERMINALS WITH
SCATTERED CUMULUS DEVELOPING BY EARLY AFTERNOON.
&&
.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 WARRANT 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...PMM
FIRE WEATHER...JTL
CLIMATE...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
236 PM MDT SAT OCT 20 2012
.UPDATE...
ISSUED AT 140 PM MDT SAT OCT 20 2012
EARLIER SENT OUT ANOTHER UPDATE. TODAYS MAXES APPROACHING FORECAST
MAXES WITH ANOTHER HOUR OR TWO OF HEATING.
UPDATE ISSUED AT 1038 AM MDT SAT OCT 20 2012
TEMPERATURES RESPONDING VERY WELL WITH DOWNSLOPE WINDS AND DRY AIR
MASS PLACE...ESPECIALLY IN THE WESTERN PORTION OF THE AREA. RUC IS
NOT ONLY CATCHING THE WARM UP WELL BUT ALSO THE WIND FIELD THE
BEST AS WELL. NAM IS ALSO CATCHING THE WARMUP AS WELL. SO PER THAT
DATA COMPARED TO THE RECENT OBSERVATIONAL TRENDS...RAISED THE
MAXES 3 TO 5 DEGREES. OTHERWISE...JUST ADJUSTED THE TRENDS ON THE
HOURLY GRIDS.
&&
.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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1142 AM MDT SAT OCT 20 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. MODELS ARE HAVE A
HARD TIME RESOLVING THE WIND FIELD AS SEVERAL SMALL SCALE
SHORTWAVE TROUGHS MOVE THROUGH IN THE WESTERLY FLOW ALOFT. NUMBER
OF WIND SHIFT LINES ASSOCIATED WITH THOSE MID LEVEL FEATURES. AT
THIS TIME NAM AND RUC LOOK TO BE DEPICTING THIS THE BEST. AS A
RESULT WINDS WILL BE SHIFTING THROUGH TONIGHT AS A RESULT OF THESE
PROGRESSIVE SURFACE TROUGHS. A FRONT MOVES INTO THE AREA BETWEEN
12Z AND 15Z TOMORROW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
203 PM MDT SAT OCT 20 2012
.UPDATE...
ISSUED AT 140 PM MDT SAT OCT 20 2012
EARLIER SENT OUT ANOTHER UPDATE. TODAYS MAXES APPROACHING FORECAST
MAXES WITH ANOTHER HOUR OR TWO OF HEATING.
UPDATE ISSUED AT 1038 AM MDT SAT OCT 20 2012
TEMPERATURES RESPONDING VERY WELL WITH DOWNSLOPE WINDS AND DRY AIR
MASS PLACE...ESPECIALLY IN THE WESTERN PORTION OF THE AREA. RUC IS
NOT ONLY CATCHING THE WARM UP WELL BUT ALSO THE WIND FIELD THE
BEST AS WELL. NAM IS ALSO CATCHING THE WARMUP AS WELL. SO PER THAT
DATA COMPARED TO THE RECENT OBSERVATIONAL TRENDS...RAISED THE
MAXES 3 TO 5 DEGREES. OTHERWISE...JUST ADJUSTED THE TRENDS ON THE
HOURLY GRIDS.
&&
.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...(TUESDAY THROUGH FRIDAY)
ISSUED AT 248 AM MDT SAT OCT 20 2012
NUMERICAL GUIDANCE IS IN DECENT AGREEMENT THROUGH 12Z TUESDAY...AT
WHICH TIME SIGNIFICANT DIFFERENCES OCCUR...LEADING TO LOW CONFIDENCE
IN THE EXTENDED PERIOD ESPECIALLY IN THE THU-FRI TIME FRAME. GFS IS
MUCH MORE AGGRESSIVE IN BRINGING A STRONG TROUGH/UPPER JET INTO THE
CENTRAL ROCKIES AFTER MID-WEEK WHILE THE EC BRINGS THESE FEATURES
ACROSS THE NORTHERN ROCKIES/NORTHERN PLAINS. BOTH MODELS DO PUSH A
COLD FRONT THROUGH THE AREA WEDNESDAY BUT THE SFC EVOLUTION AFTER
THAT DIFFERS MARKEDLY. AS A RESULT KEPT THE ALL-BLEND INIT FOR THE
EXTENDED PERIOD WITH MINIMAL CHANGES.
IN TERMS OF SENSIBLE WEATHER...CURRENT FORECAST SHOWS A CONTINUATION
OF UNSEASONABLY WARM TEMPERATURES THROUGH TUESDAY WITH HIGHS NEAR
80...BUT BY THU-FRI HIGHS IN THE 50S ARE FORECAST. KEPT THE CHANCE
OF SHOWERS GOING WEDNESDAY NIGHT FOR NOW WITH BOTH GFS/EC SHOWING AN
UPPER TROUGH PASSAGE AND DECENT JET SUPPORT AT 250 MB.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1142 AM MDT SAT OCT 20 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. MODELS ARE HAVE A
HARD TIME RESOLVING THE WIND FIELD AS SEVERAL SMALL SCALE
SHORTWAVE TROUGHS MOVE THROUGH IN THE WESTERLY FLOW ALOFT. NUMBER
OF WIND SHIFT LINES ASSOCIATED WITH THOSE MID LEVEL FEATURES. AT
THIS TIME NAM AND RUC LOOK TO BE DEPICTING THIS THE BEST. AS A
RESULT WINDS WILL BE SHIFTING THROUGH TONIGHT AS A RESULT OF THESE
PROGRESSIVE SURFACE TROUGHS. A FRONT MOVES INTO THE AREA BETWEEN
12Z AND 15Z TOMORROW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1145 AM MDT SAT OCT 20 2012
.UPDATE...
ISSUED AT 1038 AM MDT SAT OCT 20 2012
TEMPERATURES RESPONDING VERY WELL WITH DOWNSLOPE WINDS AND DRY AIR
MASS PLACE...ESPECIALLY IN THE WESTERN PORTION OF THE AREA. RUC IS
NOT ONLY CATCHING THE WARM UP WELL BUT ALSO THE WIND FIELD THE
BEST AS WELL. NAM IS ALSO CATCHING THE WARMUP AS WELL. SO PER THAT
DATA COMPARED TO THE RECENT OBSERVATIONAL TRENDS...RAISED THE
MAXES 3 TO 5 DEGREES. OTHERWISE...JUST ADJUSTED THE TRENDS ON THE
HOURLY GRIDS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 248 AM MDT SAT OCT 20 2012
WESTERLY FLOW WILL CONTINUE ACROSS THE CENTRAL PLAINS THROUGH
TONIGHT TRANSITIONING TO SOUTHWESTERLY FLOW SUNDAY AHEAD OF A TROUGH
OVER THE DESERT SOUTHWEST. THE TROUGH WILL MOVE NORTHEAST AND MOVE
INTO SOUTHWEST KANSAS MONDAY. SOUTHWEST FLOW WILL CONTINUE MONDAY
NIGHT BEHIND THE EXITING TROUGH. A SURFACE TROUGH OVER EASTERN
COLORADO WILL EVENTUALLY MOVE EAST ACROSS NORTHWEST KANSAS SUNDAY
NIGHT. HIGH PRESSURE WILL BUILD INTO NORTHWEST KANSAS MONDAY AND
MONDAY NIGHT.
SHORTWAVE ENERGY MOVES THROUGH SOUTHWEST FLOW INTO WESTERN KANSAS
SUNDAY. HOWEVER, MOISTURE IS MEAGER SO WILL KEEP POPS NIL. ALL OTHER
PERIODS LOOK DRY WITH SUBSIDENCE AND LACK OF MOISTURE.
ABOVE NORMAL TEMPERATURES IN THE LOWER 80S ARE EXPECTED TODAY.
COOLER READINGS IN THE UPPER 60S AND 70S WILL OCCUR SUNDAY AND
MONDAY. MIN TEMPERATURES WILL BE IN THE 40S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 248 AM MDT SAT OCT 20 2012
NUMERICAL GUIDANCE IS IN DECENT AGREEMENT THROUGH 12Z TUESDAY...AT
WHICH TIME SIGNIFICANT DIFFERENCES OCCUR...LEADING TO LOW CONFIDENCE
IN THE EXTENDED PERIOD ESPECIALLY IN THE THU-FRI TIME FRAME. GFS IS
MUCH MORE AGGRESSIVE IN BRINGING A STRONG TROUGH/UPPER JET INTO THE
CENTRAL ROCKIES AFTER MID-WEEK WHILE THE EC BRINGS THESE FEATURES
ACROSS THE NORTHERN ROCKIES/NORTHERN PLAINS. BOTH MODELS DO PUSH A
COLD FRONT THROUGH THE AREA WEDNESDAY BUT THE SFC EVOLUTION AFTER
THAT DIFFERS MARKEDLY. AS A RESULT KEPT THE ALL-BLEND INIT FOR THE
EXTENDED PERIOD WITH MINIMAL CHANGES.
IN TERMS OF SENSIBLE WEATHER...CURRENT FORECAST SHOWS A CONTINUATION
OF UNSEASONABLY WARM TEMPERATURES THROUGH TUESDAY WITH HIGHS NEAR
80...BUT BY THU-FRI HIGHS IN THE 50S ARE FORECAST. KEPT THE CHANCE
OF SHOWERS GOING WEDNESDAY NIGHT FOR NOW WITH BOTH GFS/EC SHOWING AN
UPPER TROUGH PASSAGE AND DECENT JET SUPPORT AT 250 MB.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1142 AM MDT SAT OCT 20 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. MODELS ARE HAVE A
HARD TIME RESOLVING THE WIND FIELD AS SEVERAL SMALL SCALE
SHORTWAVE TROUGHS MOVE THROUGH IN THE WESTERLY FLOW ALOFT. NUMBER
OF WIND SHIFT LINES ASSOCIATED WITH THOSE MID LEVEL FEATURES. AT
THIS TIME NAM AND RUC LOOK TO BE DEPICTING THIS THE BEST. AS A
RESULT WINDS WILL BE SHIFTING THROUGH TONIGHT AS A RESULT OF THESE
PROGRESSIVE SURFACE TROUGHS. A FRONT MOVES INTO THE AREA BETWEEN
12Z AND 15Z TOMORROW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...FS
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1044 AM MDT SAT OCT 20 2012
.UPDATE...
ISSUED AT 1038 AM MDT SAT OCT 20 2012
TEMPERATURES RESPONDING VERY WELL WITH DOWNSLOPE WINDS AND DRY AIR
MASS PLACE...ESPECIALLY IN THE WESTERN PORTION OF THE AREA. RUC IS
NOT ONLY CATCHING THE WARM UP WELL BUT ALSO THE WIND FIELD THE
BEST AS WELL. NAM IS ALSO CATCHING THE WARMUP AS WELL. SO PER THAT
DATA COMPARED TO THE RECENT OBSERVATIONAL TRENDS...RAISED THE
MAXES 3 TO 5 DEGREES. OTHERWISE...JUST ADJUSTED THE TRENDS ON THE
HOURLY GRIDS.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 248 AM MDT SAT OCT 20 2012
WESTERLY FLOW WILL CONTINUE ACROSS THE CENTRAL PLAINS THROUGH
TONIGHT TRANSITIONING TO SOUTHWESTERLY FLOW SUNDAY AHEAD OF A TROUGH
OVER THE DESERT SOUTHWEST. THE TROUGH WILL MOVE NORTHEAST AND MOVE
INTO SOUTHWEST KANSAS MONDAY. SOUTHWEST FLOW WILL CONTINUE MONDAY
NIGHT BEHIND THE EXITING TROUGH. A SURFACE TROUGH OVER EASTERN
COLORADO WILL EVENTUALLY MOVE EAST ACROSS NORTHWEST KANSAS SUNDAY
NIGHT. HIGH PRESSURE WILL BUILD INTO NORTHWEST KANSAS MONDAY AND
MONDAY NIGHT.
SHORTWAVE ENERGY MOVES THROUGH SOUTHWEST FLOW INTO WESTERN KANSAS
SUNDAY. HOWEVER, MOISTURE IS MEAGER SO WILL KEEP POPS NIL. ALL OTHER
PERIODS LOOK DRY WITH SUBSIDENCE AND LACK OF MOISTURE.
ABOVE NORMAL TEMPERATURES IN THE LOWER 80S ARE EXPECTED TODAY.
COOLER READINGS IN THE UPPER 60S AND 70S WILL OCCUR SUNDAY AND
MONDAY. MIN TEMPERATURES WILL BE IN THE 40S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 248 AM MDT SAT OCT 20 2012
NUMERICAL GUIDANCE IS IN DECENT AGREEMENT THROUGH 12Z TUESDAY...AT
WHICH TIME SIGNIFICANT DIFFERENCES OCCUR...LEADING TO LOW CONFIDENCE
IN THE EXTENDED PERIOD ESPECIALLY IN THE THU-FRI TIME FRAME. GFS IS
MUCH MORE AGGRESSIVE IN BRINGING A STRONG TROUGH/UPPER JET INTO THE
CENTRAL ROCKIES AFTER MID-WEEK WHILE THE EC BRINGS THESE FEATURES
ACROSS THE NORTHERN ROCKIES/NORTHERN PLAINS. BOTH MODELS DO PUSH A
COLD FRONT THROUGH THE AREA WEDNESDAY BUT THE SFC EVOLUTION AFTER
THAT DIFFERS MARKEDLY. AS A RESULT KEPT THE ALL-BLEND INIT FOR THE
EXTENDED PERIOD WITH MINIMAL CHANGES.
IN TERMS OF SENSIBLE WEATHER...CURRENT FORECAST SHOWS A CONTINUATION
OF UNSEASONABLY WARM TEMPERATURES THROUGH TUESDAY WITH HIGHS NEAR
80...BUT BY THU-FRI HIGHS IN THE 50S ARE FORECAST. KEPT THE CHANCE
OF SHOWERS GOING WEDNESDAY NIGHT FOR NOW WITH BOTH GFS/EC SHOWING AN
UPPER TROUGH PASSAGE AND DECENT JET SUPPORT AT 250 MB.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 440 AM MDT SAT OCT 20 2012
VFR CONDITIONS WILL PERSIST OVER THE NEXT 24 HOURS AT KGLD AND
KMCK. LIGHT SOUTHWEST WINDS WILL PRECEDE A TROUGH IN EASTERN
COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...FS
LONG TERM...DLF
AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 PM EDT SAT OCT 20 2012
.UPDATE...
ISSUED AT 950 AM EDT SAT OCT 20 2012
THE FORECAST APPEARS TO BE ON TRACK THIS MORNING WITH MINIMAL TWEAKS
TO HOURLY TEMPS AND DEW PTS. LOOKING AT THE FIRST ECHOS OF THE DAY
DRIFTING THROUGH FLEMING AND ROWAN COUNTIES IT IS APPARENT THAT
LITTLE IF ANY OF THIS IS REACHING THE GROUND AND WILL CONTINUE WITH
THE IDEA OF SCATTERED SPRINKLES THROUGH THE DAY PRIMARILY ALONG AND
NORTH OF THE MOUNTAIN PARKWAY. ZONES AND HWO LOOK GOOD...AND NO
UPDATE APPEARS TO BE NEEDED THERE ATTM.
UPDATE ISSUED AT 724 AM EDT SAT OCT 20 2012
TEMPERATURES HAVE STAYED UP IN THE MID AND UPPER 40S THIS MORNING DUE
TO THE EXTENSIVE CLOUD COVER. HAVE FRESHENED UP THE FORECAST GRIDS TO
RESEMBLE THIS. OTHERWISE...THE FORECAST IS GOOD TO GO.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 346 AM EDT SAT OCT 20 2012
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE AN UPPER LEVEL
LOW CENTERED OVER MI KEEPING CONTINUED CLOUD COVER OVER THE OHIO
VALLEY. THEREFORE...THIS WILL KEEP MORNING TEMPERATURES WARM IN THE
MID 40S. WITH THE HEATING OF DAY AND AT LEAST A TAD OF INSTABILITY
AND THE UPPER LEVEL LOW PROVIDING SEVERAL WEAK VORT MAXES MOVING
THROUGH...WILL KEEP ISOLATED SPRINKLES ACROSS THE AREA THROUGH THE
AFTERNOON...MAINLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY. GIVEN
THE CURRENT TREND OF THE MODELS...WILL LEAN TOWARD A SLOWER EXIT OF
THE UPPER LOW TO THE NORTHEAST. THEREFORE...KEEPING HIGH TEMPS FOR
TODAY TEMPERED TO THE UPPER 50S. LOCALES SUCH AS BLACK MOUNTAIN WILL
STRUGGLE TO REACH THE MID 40S.
HEADING INTO TONIGHT...THE FORECAST CHALLENGE ARISES...AS THE NAM
AND RUC HINT AT THE UPPER LOW AND ASSOCIATED 850 MOISTURE/CLOUD
COVER FINALLY EXITING TO THE NORTHEAST. THIS PROCESS CONTINUING
THROUGH TONIGHT WILL SLOWLY ALLOW CLEARING FROM THE SOUTHWEST TO THE
NORTHEAST. SO HAVE TRIED TO SHOW THIS IN THE SUN NIGHT MIN TEMPS AS
STATIONS SUCH AS MONTICELLO COULD BOTTOM OUT INTO THE MID 30S
TONIGHT. SO WENT WITH A SIGNIFICANT RIDGE VALLEY SPLIT WHERE AREAS
WILL CLEAR OUT ALONG WITH A GENERAL GRADIENT WITH THE SOUTHWEST
BEING COOLER TO THE NORTHEAST BEING WARMER AS THE CLOUD COVER EXITS.
THIS WILL ALSO ALLOW FOR SOME EXTENSIVE FOG DEVELOPMENT TONIGHT
ESPECIALLY WHERE AREAS CLEAR OUT. THE COLDEST LOCATIONS WILL ALSO
SEE SOME PATCHY FROST.
FOR SUNDAY...CLOUD COVER IS EXPECT TO CLEAR OUT WITH A SHORTWAVE
RIDGE OVERHEAD AND AN OVERALL GREAT WEATHER DAY WITH LIGHT SOUTHERLY
WINDS. HEATING TO START THE DAY WILL BE HINDERED AT FIRST AS MORNING
FOG WILL BE SLOW TO BURN OFF. HEADING INTO THE COLDER MONTHS MORNING
FOG WILL TAKE A BIT LATER TO CLEAR OUT. BUT SUNDAYS HIGHS WILL
QUICKLY WARM INTO THE UPPER 60S AND AROUND 70 IN SOUTHERLY FLOW. SO
A PLEASANT AND DRY FORECAST IS ON TAP BY SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 346 AM EDT SAT OCT 20 2012
AT THE START OF THE PERIOD...A TROUGH IS EXPECTED TO BE DEPARTING
THE NORTHEASTERN US WITH RIDGING EXTENDING FROM MEXICO NORTH INTO THE
WESTERN GULF AND MUCH OF THE SOUTHEASTERN US AND MS VALLEY TO LOWER
OH VALLEY REGIONS. MEANWHILE A TROUGH IS EXPECTED TO BE DIGGING OFF
THE NORTHWEST COAST. A COUPLE OF SHORTWAVES PER MODEL CONSENSUS ARE
EXPECTED TO BE WORKING AROUND THE SOUTHEASTERN RIDGING...ONE MOVING
THROUGH THE PLAINS AND APPROACHING THE MID MS VALLEY REGION AT THE
START OF THE PERIOD WITH ANOTHER WORKING FROM THE DESERT SOUTHWEST
TOWARD THE SOUTHERN PLAINS.
THROUGH MONDAY NIGHT AND TUESDAY...HEIGHTS WILL RISE ALONG THE
EASTERN SEABOARD AS THE TROUGH DEPARTS THE NORTHEASTERN US WITH
RIDGING EXTENDING FROM MEXICO ACROSS THE GULF AND INTO THE
SOUTHEASTERN STATES AROUND 12Z TUE PER MODEL CONSENSUS. THE FIRST OF
THE SHORTWAVES MENTIONED PREVIOUSLY IS PROGGED TO PASS WELL TO OUR
NW AND THEN NORTH AS IT MOVES IT AROUND THE RIDGING FROM SUN NIGHT
INTO MONDAY. FAIRLY CLOSE ON ITS HEELS WILL BE THE NEXT SHORTWAVE
WORKING ACROSS THE PLAINS AND TOWARD THE MID MS VALLEY REGION AND
THEN NORTH OF THE AREA ON TUE. BOTH OF THESE SHOULD BRING JUST SOME
HIGH AND MID CLOUDS FOR THE MOST PART...WITH ANY PRECIP CHANCES WELL
WEST AND NORTH OF THE REGION. RIDING SHOULD THEN REASSERT ITSELF AT
MIDWEEK OVER THE WESTERN GULF AND INTO THE SOUTHEASTERN US...WITH A
RATHER BROAD TROUGH OVER THE WESTERN US AND EAST INTO THE PLAINS. A
SHORTWAVE TROUGH ASSOCIATED WITH THIS BROAD THROUGH SHOULD GRADUALLY
EJECT NORTHEAST TOWARD THE GREAT LAKES ON THU INTO THU NIGHT WITH
RATHER ZONAL FLOW LEFT IN PLACE AT MIDWEEK. THERE ARE TIMING
DIFFERENCES WITH THIS LAST SHORTWAVE AND THE EVOLUTION/STRENGTH OF A
CLOSED LOW OVER THE GREAT LAKES/ONTARIO AREA AT THE END OF THE WEEK.
HOWEVER...YET ANOTHER IN A SERIES OF SFC LOWS TRACKING ACROSS THE
PLAINS AND INTO THE GREAT LAKES REGION IS ANTICIPATED WITH THE
TRAILING RATHER SHEARED OUT BOUNDARY WORKING INTO THE REGION LATE IN
THE PERIOD. THE ECMWF RUNS HAVE BEEN FASTER WITH THIS BOUNDARY OVER
THE PAST FEW RUNS COMPARED TO THE GFS RUN.
SFC RIDGING SHIFTING EAST INITIALLY IN THE PERIOD ALONG WITH SOME
SUBSIDENCE ASSOCIATED WITH HEIGHT RISES SHOULD BE FAVORABLE FOR
RIVER VALLEY FOG ON SUN NIGHT AND A RIDGE/VALLEY TEMP SPLIT. MANY OF
THE VALLEY LOCATIONS...ESPECIALLY EAST SHOULD REACH THE UPPER 30S TO
LOW 40S ON SUN NIGHT. TEMPERATURES WILL CONTINUE TO MODERATE
ASSOCIATED WITH THE RISING HEIGHTS AND SOUTHERLY FLOW ON MON. THE
MODEL CONSENSUS IS CURRENTLY BELOW THE MEX NUMBERS...BUT NUDGED
TEMPS A DEGREE ABOVE THE MODEL CONSENSUS FOR MON. MIN T SHOULD
MODERATE ON MON NIGHT AS WELL...THOUGH A RIDGE/VALLEY SPLIT IS STILL
EXPECTED OVER THE SOUTHEASTERN COUNTIES WITH A SIMILAR MAGNITUDE AS
SUN NIGHT. MIN T ON TUE NIGHT SHOULD BE A COLDER ON AVERAGE COMPARED
TO MON NIGHT WITH THE RIDGE STARTING TO REASSERT ITSELF AND A BIT
LESS CLOUD COVER ON AVERAGE WITH YET ANOTHER IN A SERIES OF
RIDGE/VALLEY TEMP SPLITS. WED NIGHT SHOULD ALSO FAVOR A RIDGE/VALLEY
TEMP SPLIT...BUT THU NIGHT SHOULD FEATURE A MINIMAL OR NO
RIDGE/VALLEY TEMP SPLIT AS THE GRADIENT INCREASES AHEAD OF AN
APPROACHING COLD FRONT. SOME TERRAIN ADJUSTMENTS WERE MADE TO THE
GRID LOAD FOR MIN T FROM MON NIGHT THROUGH WED NIGHT TO REFLECT THE
ABOVE MENTIONED RIDGE/VALLEY TEMP SPLITS.
MAX TEMPS WILL MODERATE FURTHER INTO MIDWEEK AND REMAIN ABOVE NORMAL
THROUGH THE END OF THE PERIOD. MAX TEMPS SHOULD NEAR 15 DEGREES
ABOVE NORMAL ON WED AS 850 MB TEMPS REACH ABOUT THE 12 TO 15C RANGE.
WED IS EXPECTED TO BE THE WARMEST DAY. DURING THE PAST COUPLE OF
WARMER DAYS THE MEX HAS BEEN TOO WARM WITH MAX T AND THE GRID LOAD
TEMPS IN THE UPPER 70S WERE ACCEPTED.
THE ONLY POPS IN THE PERIOD WILL COME AT THE END OF THE PERIOD. IF
THE FASTER ECMWF IS RIGHT OR MODELS TREND TOWARD IT...THEN POPS MAY
NEED TO BE INCREASED ON THU NIGHT. HOWEVER...THE MODEL CONSENSUS
GRID LOAD FAVORED POPS MAINLY ON FRI...AND THIS SEEMED TO BE A
REASONABLE COMPROMISE GIVEN THE MODEL DIFFERENCES NOTED ABOVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 135 PM EDT SAT OCT 20 2012
CIGS REMAIN IN THE LOW END VFR TERRITORY THROUGH 00Z BEFORE GRADUALLY
LIFTING OUT OVERNIGHT AS HIGH PRESSURE BEGINS TO MOVE IN FROM THE
SW...BRINGING CALM WINDS ALONG WITH A POTENTIAL FOR IFR FOG OR WORSE
TOWARDS DAYBREAK AROUND THE VALLEYS. ANY FOG THAT DEVELOPS WILL BEGIN
TO MIX OUT BY 13Z WITH VFR PREVAILING UNDER CLEAR SKIES AND CONTINUED
LIGHT WINDS THROUGH THE REMAINDER OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER/MB
SHORT TERM...SHALLENBERGER
LONG TERM....JP
AVIATION...MB
AREA FORECAST DISCUSSION
NWS JACKSON KY
950 AM EDT SAT OCT 20 2012
.UPDATE...
ISSUED AT 950 AM EDT SAT OCT 20 2012
THE FORECAST APPEARS TO BE ON TRACK THIS MORNING WITH MINIMAL TWEAKS
TO HOURLY TEMPS AND DEW PTS. LOOKING AT THE FIRST ECHOS OF THE DAY
DRIFTING THROUGH FLEMING AND ROWAN COUNTIES IT IS APPARENT THAT
LITTLE IF ANY OF THIS IS REACHING THE GROUND AND WILL CONTINUE WITH
THE IDEA OF SCATTERED SPRINKLES THROUGH THE DAY PRIMARILY ALONG AND
NORTH OF THE MOUNTAIN PARKWAY. ZONES AND HWO LOOK GOOD...AND NO
UPDATE APPEARS TO BE NEEDED THERE ATTM.
UPDATE ISSUED AT 724 AM EDT SAT OCT 20 2012
TEMPERATURES HAVE STAYED UP IN THE MID AND UPPER 40S THIS MORNING DUE
TO THE EXTENSIVE CLOUD COVER. HAVE FRESHENED UP THE FORECAST GRIDS TO
RESEMBLE THIS. OTHERWISE...THE FORECAST IS GOOD TO GO.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 346 AM EDT SAT OCT 20 2012
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE AN UPPER LEVEL
LOW CENTERED OVER MI KEEPING CONTINUED CLOUD COVER OVER THE OHIO
VALLEY. THEREFORE...THIS WILL KEEP MORNING TEMPERATURES WARM IN THE
MID 40S. WITH THE HEATING OF DAY AND AT LEAST A TAD OF INSTABILITY
AND THE UPPER LEVEL LOW PROVIDING SEVERAL WEAK VORT MAXES MOVING
THROUGH...WILL KEEP ISOLATED SPRINKLES ACROSS THE AREA THROUGH THE
AFTERNOON...MAINLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY. GIVEN
THE CURRENT TREND OF THE MODELS...WILL LEAN TOWARD A SLOWER EXIT OF
THE UPPER LOW TO THE NORTHEAST. THEREFORE...KEEPING HIGH TEMPS FOR
TODAY TEMPERED TO THE UPPER 50S. LOCALES SUCH AS BLACK MOUNTAIN WILL
STRUGGLE TO REACH THE MID 40S.
HEADING INTO TONIGHT...THE FORECAST CHALLENGE ARISES...AS THE NAM
AND RUC HINT AT THE UPPER LOW AND ASSOCIATED 850 MOISTURE/CLOUD
COVER FINALLY EXITING TO THE NORTHEAST. THIS PROCESS CONTINUING
THROUGH TONIGHT WILL SLOWLY ALLOW CLEARING FROM THE SOUTHWEST TO THE
NORTHEAST. SO HAVE TRIED TO SHOW THIS IN THE SUN NIGHT MIN TEMPS AS
STATIONS SUCH AS MONTICELLO COULD BOTTOM OUT INTO THE MID 30S
TONIGHT. SO WENT WITH A SIGNIFICANT RIDGE VALLEY SPLIT WHERE AREAS
WILL CLEAR OUT ALONG WITH A GENERAL GRADIENT WITH THE SOUTHWEST
BEING COOLER TO THE NORTHEAST BEING WARMER AS THE CLOUD COVER EXITS.
THIS WILL ALSO ALLOW FOR SOME EXTENSIVE FOG DEVELOPMENT TONIGHT
ESPECIALLY WHERE AREAS CLEAR OUT. THE COLDEST LOCATIONS WILL ALSO
SEE SOME PATCHY FROST.
FOR SUNDAY...CLOUD COVER IS EXPECT TO CLEAR OUT WITH A SHORTWAVE
RIDGE OVERHEAD AND AN OVERALL GREAT WEATHER DAY WITH LIGHT SOUTHERLY
WINDS. HEATING TO START THE DAY WILL BE HINDERED AT FIRST AS MORNING
FOG WILL BE SLOW TO BURN OFF. HEADING INTO THE COLDER MONTHS MORNING
FOG WILL TAKE A BIT LATER TO CLEAR OUT. BUT SUNDAYS HIGHS WILL
QUICKLY WARM INTO THE UPPER 60S AND AROUND 70 IN SOUTHERLY FLOW. SO
A PLEASANT AND DRY FORECAST IS ON TAP BY SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 346 AM EDT SAT OCT 20 2012
AT THE START OF THE PERIOD...A TROUGH IS EXPECTED TO BE DEPARTING
THE NORTHEASTERN US WITH RIDGING EXTENDING FROM MEXICO NORTH INTO THE
WESTERN GULF AND MUCH OF THE SOUTHEASTERN US AND MS VALLEY TO LOWER
OH VALLEY REGIONS. MEANWHILE A TROUGH IS EXPECTED TO BE DIGGING OFF
THE NORTHWEST COAST. A COUPLE OF SHORTWAVES PER MODEL CONSENSUS ARE
EXPECTED TO BE WORKING AROUND THE SOUTHEASTERN RIDGING...ONE MOVING
THROUGH THE PLAINS AND APPROACHING THE MID MS VALLEY REGION AT THE
START OF THE PERIOD WITH ANOTHER WORKING FROM THE DESERT SOUTHWEST
TOWARD THE SOUTHERN PLAINS.
THROUGH MONDAY NIGHT AND TUESDAY...HEIGHTS WILL RISE ALONG THE
EASTERN SEABOARD AS THE TROUGH DEPARTS THE NORTHEASTERN US WITH
RIDGING EXTENDING FROM MEXICO ACROSS THE GULF AND INTO THE
SOUTHEASTERN STATES AROUND 12Z TUE PER MODEL CONSENSUS. THE FIRST OF
THE SHORTWAVES MENTIONED PREVIOUSLY IS PROGGED TO PASS WELL TO OUR
NW AND THEN NORTH AS IT MOVES IT AROUND THE RIDGING FROM SUN NIGHT
INTO MONDAY. FAIRLY CLOSE ON ITS HEELS WILL BE THE NEXT SHORTWAVE
WORKING ACROSS THE PLAINS AND TOWARD THE MID MS VALLEY REGION AND
THEN NORTH OF THE AREA ON TUE. BOTH OF THESE SHOULD BRING JUST SOME
HIGH AND MID CLOUDS FOR THE MOST PART...WITH ANY PRECIP CHANCES WELL
WEST AND NORTH OF THE REGION. RIDING SHOULD THEN REASSERT ITSELF AT
MIDWEEK OVER THE WESTERN GULF AND INTO THE SOUTHEASTERN US...WITH A
RATHER BROAD TROUGH OVER THE WESTERN US AND EAST INTO THE PLAINS. A
SHORTWAVE TROUGH ASSOCIATED WITH THIS BROAD THROUGH SHOULD GRADUALLY
EJECT NORTHEAST TOWARD THE GREAT LAKES ON THU INTO THU NIGHT WITH
RATHER ZONAL FLOW LEFT IN PLACE AT MIDWEEK. THERE ARE TIMING
DIFFERENCES WITH THIS LAST SHORTWAVE AND THE EVOLUTION/STRENGTH OF A
CLOSED LOW OVER THE GREAT LAKES/ONTARIO AREA AT THE END OF THE WEEK.
HOWEVER...YET ANOTHER IN A SERIES OF SFC LOWS TRACKING ACROSS THE
PLAINS AND INTO THE GREAT LAKES REGION IS ANTICIPATED WITH THE
TRAILING RATHER SHEARED OUT BOUNDARY WORKING INTO THE REGION LATE IN
THE PERIOD. THE ECMWF RUNS HAVE BEEN FASTER WITH THIS BOUNDARY OVER
THE PAST FEW RUNS COMPARED TO THE GFS RUN.
SFC RIDGING SHIFTING EAST INITIALLY IN THE PERIOD ALONG WITH SOME
SUBSIDENCE ASSOCIATED WITH HEIGHT RISES SHOULD BE FAVORABLE FOR
RIVER VALLEY FOG ON SUN NIGHT AND A RIDGE/VALLEY TEMP SPLIT. MANY OF
THE VALLEY LOCATIONS...ESPECIALLY EAST SHOULD REACH THE UPPER 30S TO
LOW 40S ON SUN NIGHT. TEMPERATURES WILL CONTINUE TO MODERATE
ASSOCIATED WITH THE RISING HEIGHTS AND SOUTHERLY FLOW ON MON. THE
MODEL CONSENSUS IS CURRENTLY BELOW THE MEX NUMBERS...BUT NUDGED
TEMPS A DEGREE ABOVE THE MODEL CONSENSUS FOR MON. MIN T SHOULD
MODERATE ON MON NIGHT AS WELL...THOUGH A RIDGE/VALLEY SPLIT IS STILL
EXPECTED OVER THE SOUTHEASTERN COUNTIES WITH A SIMILAR MAGNITUDE AS
SUN NIGHT. MIN T ON TUE NIGHT SHOULD BE A COLDER ON AVERAGE COMPARED
TO MON NIGHT WITH THE RIDGE STARTING TO REASSERT ITSELF AND A BIT
LESS CLOUD COVER ON AVERAGE WITH YET ANOTHER IN A SERIES OF
RIDGE/VALLEY TEMP SPLITS. WED NIGHT SHOULD ALSO FAVOR A RIDGE/VALLEY
TEMP SPLIT...BUT THU NIGHT SHOULD FEATURE A MINIMAL OR NO
RIDGE/VALLEY TEMP SPLIT AS THE GRADIENT INCREASES AHEAD OF AN
APPROACHING COLD FRONT. SOME TERRAIN ADJUSTMENTS WERE MADE TO THE
GRID LOAD FOR MIN T FROM MON NIGHT THROUGH WED NIGHT TO REFLECT THE
ABOVE MENTIONED RIDGE/VALLEY TEMP SPLITS.
MAX TEMPS WILL MODERATE FURTHER INTO MIDWEEK AND REMAIN ABOVE NORMAL
THROUGH THE END OF THE PERIOD. MAX TEMPS SHOULD NEAR 15 DEGREES
ABOVE NORMAL ON WED AS 850 MB TEMPS REACH ABOUT THE 12 TO 15C RANGE.
WED IS EXPECTED TO BE THE WARMEST DAY. DURING THE PAST COUPLE OF
WARMER DAYS THE MEX HAS BEEN TOO WARM WITH MAX T AND THE GRID LOAD
TEMPS IN THE UPPER 70S WERE ACCEPTED.
THE ONLY POPS IN THE PERIOD WILL COME AT THE END OF THE PERIOD. IF
THE FASTER ECMWF IS RIGHT OR MODELS TREND TOWARD IT...THEN POPS MAY
NEED TO BE INCREASED ON THU NIGHT. HOWEVER...THE MODEL CONSENSUS
GRID LOAD FAVORED POPS MAINLY ON FRI...AND THIS SEEMED TO BE A
REASONABLE COMPROMISE GIVEN THE MODEL DIFFERENCES NOTED ABOVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 724 AM EDT SAT OCT 20 2012
WILL EXPECT A 4 KFT LAYER TO BE PERSISTENT THROUGH THE DAY TODAY
WITH A 5 TO 10 KNOT WEST WINDS BEFORE DECOUPLING BY 23Z. WITH
CLEARING SKIES TONIGHT...PATCHY DENSE FOG WILL DEVELOP. SME AND LOZ
WILL DROP TO VLIFR VISIBILITY BY 10Z TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER/MB
SHORT TERM...SHALLENBERGER
LONG TERM....JP
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
722 AM EDT SAT OCT 20 2012
.UPDATE...
ISSUED AT 724 AM EDT SAT OCT 20 2012
TEMPERATURES HAVE STAYED UP IN THE MID AND UPPER 40S THIS MORNING DUE
TO THE EXTENSIVE CLOUD COVER. HAVE FRESHENED UP THE FORECAST GRIDS TO
RESEMBLE THIS. OTHERWISE...THE FORECAST IS GOOD TO GO.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 346 AM EDT SAT OCT 20 2012
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE AN UPPER LEVEL
LOW CENTERED OVER MI KEEPING CONTINUED CLOUD COVER OVER THE OHIO
VALLEY. THEREFORE...THIS WILL KEEP MORNING TEMPERATURES WARM IN THE
MID 40S. WITH THE HEATING OF DAY AND AT LEAST A TAD OF INSTABILITY
AND THE UPPER LEVEL LOW PROVIDING SEVERAL WEAK VORT MAXES MOVING
THROUGH...WILL KEEP ISOLATED SPRINKLES ACROSS THE AREA THROUGH THE
AFTERNOON...MAINLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY. GIVEN
THE CURRENT TREND OF THE MODELS...WILL LEAN TOWARD A SLOWER EXIT OF
THE UPPER LOW TO THE NORTHEAST. THEREFORE...KEEPING HIGH TEMPS FOR
TODAY TEMPERED TO THE UPPER 50S. LOCALES SUCH AS BLACK MOUNTAIN WILL
STRUGGLE TO REACH THE MID 40S.
HEADING INTO TONIGHT...THE FORECAST CHALLENGE ARISES...AS THE NAM
AND RUC HINT AT THE UPPER LOW AND ASSOCIATED 850 MOISTURE/CLOUD
COVER FINALLY EXITING TO THE NORTHEAST. THIS PROCESS CONTINUING
THROUGH TONIGHT WILL SLOWLY ALLOW CLEARING FROM THE SOUTHWEST TO THE
NORTHEAST. SO HAVE TRIED TO SHOW THIS IN THE SUN NIGHT MIN TEMPS AS
STATIONS SUCH AS MONTICELLO COULD BOTTOM OUT INTO THE MID 30S
TONIGHT. SO WENT WITH A SIGNIFICANT RIDGE VALLEY SPLIT WHERE AREAS
WILL CLEAR OUT ALONG WITH A GENERAL GRADIENT WITH THE SOUTHWEST
BEING COOLER TO THE NORTHEAST BEING WARMER AS THE CLOUD COVER EXITS.
THIS WILL ALSO ALLOW FOR SOME EXTENSIVE FOG DEVELOPMENT TONIGHT
ESPECIALLY WHERE AREAS CLEAR OUT. THE COLDEST LOCATIONS WILL ALSO
SEE SOME PATCHY FROST.
FOR SUNDAY...CLOUD COVER IS EXPECT TO CLEAR OUT WITH A SHORTWAVE
RIDGE OVERHEAD AND AN OVERALL GREAT WEATHER DAY WITH LIGHT SOUTHERLY
WINDS. HEATING TO START THE DAY WILL BE HINDERED AT FIRST AS MORNING
FOG WILL BE SLOW TO BURN OFF. HEADING INTO THE COLDER MONTHS MORNING
FOG WILL TAKE A BIT LATER TO CLEAR OUT. BUT SUNDAYS HIGHS WILL
QUICKLY WARM INTO THE UPPER 60S AND AROUND 70 IN SOUTHERLY FLOW. SO
A PLEASANT AND DRY FORECAST IS ON TAP BY SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 346 AM EDT SAT OCT 20 2012
AT THE START OF THE PERIOD...A TROUGH IS EXPECTED TO BE DEPARTING
THE NORTHEASTERN US WITH RIDGING EXTENDING FROM MEXICO NORTH INTO THE
WESTERN GULF AND MUCH OF THE SOUTHEASTERN US AND MS VALLEY TO LOWER
OH VALLEY REGIONS. MEANWHILE A TROUGH IS EXPECTED TO BE DIGGING OFF
THE NORTHWEST COAST. A COUPLE OF SHORTWAVES PER MODEL CONSENSUS ARE
EXPECTED TO BE WORKING AROUND THE SOUTHEASTERN RIDGING...ONE MOVING
THROUGH THE PLAINS AND APPROACHING THE MID MS VALLEY REGION AT THE
START OF THE PERIOD WITH ANOTHER WORKING FROM THE DESERT SOUTHWEST
TOWARD THE SOUTHERN PLAINS.
THROUGH MONDAY NIGHT AND TUESDAY...HEIGHTS WILL RISE ALONG THE
EASTERN SEABOARD AS THE TROUGH DEPARTS THE NORTHEASTERN US WITH
RIDGING EXTENDING FROM MEXICO ACROSS THE GULF AND INTO THE
SOUTHEASTERN STATES AROUND 12Z TUE PER MODEL CONSENSUS. THE FIRST OF
THE SHORTWAVES MENTIONED PREVIOUSLY IS PROGGED TO PASS WELL TO OUR
NW AND THEN NORTH AS IT MOVES IT AROUND THE RIDGING FROM SUN NIGHT
INTO MONDAY. FAIRLY CLOSE ON ITS HEELS WILL BE THE NEXT SHORTWAVE
WORKING ACROSS THE PLAINS AND TOWARD THE MID MS VALLEY REGION AND
THEN NORTH OF THE AREA ON TUE. BOTH OF THESE SHOULD BRING JUST SOME
HIGH AND MID CLOUDS FOR THE MOST PART...WITH ANY PRECIP CHANCES WELL
WEST AND NORTH OF THE REGION. RIDING SHOULD THEN REASSERT ITSELF AT
MIDWEEK OVER THE WESTERN GULF AND INTO THE SOUTHEASTERN US...WITH A
RATHER BROAD TROUGH OVER THE WESTERN US AND EAST INTO THE PLAINS. A
SHORTWAVE TROUGH ASSOCIATED WITH THIS BROAD THROUGH SHOULD GRADUALLY
EJECT NORTHEAST TOWARD THE GREAT LAKES ON THU INTO THU NIGHT WITH
RATHER ZONAL FLOW LEFT IN PLACE AT MIDWEEK. THERE ARE TIMING
DIFFERENCES WITH THIS LAST SHORTWAVE AND THE EVOLUTION/STRENGTH OF A
CLOSED LOW OVER THE GREAT LAKES/ONTARIO AREA AT THE END OF THE WEEK.
HOWEVER...YET ANOTHER IN A SERIES OF SFC LOWS TRACKING ACROSS THE
PLAINS AND INTO THE GREAT LAKES REGION IS ANTICIPATED WITH THE
TRAILING RATHER SHEARED OUT BOUNDARY WORKING INTO THE REGION LATE IN
THE PERIOD. THE ECMWF RUNS HAVE BEEN FASTER WITH THIS BOUNDARY OVER
THE PAST FEW RUNS COMPARED TO THE GFS RUN.
SFC RIDGING SHIFTING EAST INITIALLY IN THE PERIOD ALONG WITH SOME
SUBSIDENCE ASSOCIATED WITH HEIGHT RISES SHOULD BE FAVORABLE FOR
RIVER VALLEY FOG ON SUN NIGHT AND A RIDGE/VALLEY TEMP SPLIT. MANY OF
THE VALLEY LOCATIONS...ESPECIALLY EAST SHOULD REACH THE UPPER 30S TO
LOW 40S ON SUN NIGHT. TEMPERATURES WILL CONTINUE TO MODERATE
ASSOCIATED WITH THE RISING HEIGHTS AND SOUTHERLY FLOW ON MON. THE
MODEL CONSENSUS IS CURRENTLY BELOW THE MEX NUMBERS...BUT NUDGED
TEMPS A DEGREE ABOVE THE MODEL CONSENSUS FOR MON. MIN T SHOULD
MODERATE ON MON NIGHT AS WELL...THOUGH A RIDGE/VALLEY SPLIT IS STILL
EXPECTED OVER THE SOUTHEASTERN COUNTIES WITH A SIMILAR MAGNITUDE AS
SUN NIGHT. MIN T ON TUE NIGHT SHOULD BE A COLDER ON AVERAGE COMPARED
TO MON NIGHT WITH THE RIDGE STARTING TO REASSERT ITSELF AND A BIT
LESS CLOUD COVER ON AVERAGE WITH YET ANOTHER IN A SERIES OF
RIDGE/VALLEY TEMP SPLITS. WED NIGHT SHOULD ALSO FAVOR A RIDGE/VALLEY
TEMP SPLIT...BUT THU NIGHT SHOULD FEATURE A MINIMAL OR NO
RIDGE/VALLEY TEMP SPLIT AS THE GRADIENT INCREASES AHEAD OF AN
APPROACHING COLD FRONT. SOME TERRAIN ADJUSTMENTS WERE MADE TO THE
GRID LOAD FOR MIN T FROM MON NIGHT THROUGH WED NIGHT TO REFLECT THE
ABOVE MENTIONED RIDGE/VALLEY TEMP SPLITS.
MAX TEMPS WILL MODERATE FURTHER INTO MIDWEEK AND REMAIN ABOVE NORMAL
THROUGH THE END OF THE PERIOD. MAX TEMPS SHOULD NEAR 15 DEGREES
ABOVE NORMAL ON WED AS 850 MB TEMPS REACH ABOUT THE 12 TO 15C RANGE.
WED IS EXPECTED TO BE THE WARMEST DAY. DURING THE PAST COUPLE OF
WARMER DAYS THE MEX HAS BEEN TOO WARM WITH MAX T AND THE GRID LOAD
TEMPS IN THE UPPER 70S WERE ACCEPTED.
THE ONLY POPS IN THE PERIOD WILL COME AT THE END OF THE PERIOD. IF
THE FASTER ECMWF IS RIGHT OR MODELS TREND TOWARD IT...THEN POPS MAY
NEED TO BE INCREASED ON THU NIGHT. HOWEVER...THE MODEL CONSENSUS
GRID LOAD FAVORED POPS MAINLY ON FRI...AND THIS SEEMED TO BE A
REASONABLE COMPROMISE GIVEN THE MODEL DIFFERENCES NOTED ABOVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 724 AM EDT SAT OCT 20 2012
WILL EXPECT A 4 KFT LAYER TO BE PERSISTENT THROUGH THE DAY TODAY
WITH A 5 TO 10 KNOT WEST WINDS BEFORE DECOUPLING BY 23Z. WITH
CLEARING SKIES TONIGHT...PATCHY DENSE FOG WILL DEVELOP. SME AND LOZ
WILL DROP TO VLIFR VISIBILITY BY 10Z TONIGHT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM....JP
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
346 AM EDT SAT OCT 20 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 346 AM EDT SAT OCT 20 2012
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE AN UPPER LEVEL
LOW CENTERED OVER MI KEEPING CONTINUED CLOUD COVER OVER THE OHIO
VALLEY. THEREFORE...THIS WILL KEEP MORNING TEMPERATURES WARM IN THE
MID 40S. WITH THE HEATING OF DAY AND AT LEAST A TAD OF INSTABILITY
AND THE UPPER LEVEL LOW PROVIDING SEVERAL WEAK VORT MAXES MOVING
THROUGH...WILL KEEP ISOLATED SPRINKLES ACROSS THE AREA THROUGH THE
AFTERNOON...MAINLY ALONG AND NORTH OF THE MOUNTAIN PARKWAY. GIVEN
THE CURRENT TREND OF THE MODELS...WILL LEAN TOWARD A SLOWER EXIT OF
THE UPPER LOW TO THE NORTHEAST. THEREFORE...KEEPING HIGH TEMPS FOR
TODAY TEMPERED TO THE UPPER 50S. LOCALES SUCH AS BLACK MOUNTAIN WILL
STRUGGLE TO REACH THE MID 40S.
HEADING INTO TONIGHT...THE FORECAST CHALLENGE ARISES...AS THE NAM
AND RUC HINT AT THE UPPER LOW AND ASSOCIATED 850 MOISTURE/CLOUD
COVER FINALLY EXITING TO THE NORTHEAST. THIS PROCESS CONTINUING
THROUGH TONIGHT WILL SLOWLY ALLOW CLEARING FROM THE SOUTHWEST TO THE
NORTHEAST. SO HAVE TRIED TO SHOW THIS IN THE SUN NIGHT MIN TEMPS AS
STATIONS SUCH AS MONTICELLO COULD BOTTOM OUT INTO THE MID 30S
TONIGHT. SO WENT WITH A SIGNIFICANT RIDGE VALLEY SPLIT WHERE AREAS
WILL CLEAR OUT ALONG WITH A GENERAL GRADIENT WITH THE SOUTHWEST
BEING COOLER TO THE NORTHEAST BEING WARMER AS THE CLOUD COVER EXITS.
THIS WILL ALSO ALLOW FOR SOME EXTENSIVE FOG DEVELOPMENT TONIGHT
ESPECIALLY WHERE AREAS CLEAR OUT. THE COLDEST LOCATIONS WILL ALSO
SEE SOME PATCHY FROST.
FOR SUNDAY...CLOUD COVER IS EXPECT TO CLEAR OUT WITH A SHORTWAVE
RIDGE OVERHEAD AND AN OVERALL GREAT WEATHER DAY WITH LIGHT SOUTHERLY
WINDS. HEATING TO START THE DAY WILL BE HINDERED AT FIRST AS MORNING
FOG WILL BE SLOW TO BURN OFF. HEADING INTO THE COLDER MONTHS MORNING
FOG WILL TAKE A BIT LATER TO CLEAR OUT. BUT SUNDAYS HIGHS WILL
QUICKLY WARM INTO THE UPPER 60S AND AROUND 70 IN SOUTHERLY FLOW. SO
A PLEASANT AND DRY FORECAST IS ON TAP BY SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 346 AM EDT SAT OCT 20 2012
AT THE START OF THE PERIOD...A TROUGH IS EXPECTED TO BE DEPARTING
THE NORTHEASTERN US WITH RIDGING EXTENDING FROM MEXICO NORTH INTO THE
WESTERN GULF AND MUCH OF THE SOUTHEASTERN US AND MS VALLEY TO LOWER
OH VALLEY REGIONS. MEANWHILE A TROUGH IS EXPECTED TO BE DIGGING OFF
THE NORTHWEST COAST. A COUPLE OF SHORTWAVES PER MODEL CONSENSUS ARE
EXPECTED TO BE WORKING AROUND THE SOUTHEASTERN RIDGING...ONE MOVING
THROUGH THE PLAINS AND APPROACHING THE MID MS VALLEY REGION AT THE
START OF THE PERIOD WITH ANOTHER WORKING FROM THE DESERT SOUTHWEST
TOWARD THE SOUTHERN PLAINS.
THROUGH MONDAY NIGHT AND TUESDAY...HEIGHTS WILL RISE ALONG THE
EASTERN SEABOARD AS THE TROUGH DEPARTS THE NORTHEASTERN US WITH
RIDGING EXTENDING FROM MEXICO ACROSS THE GULF AND INTO THE
SOUTHEASTERN STATES AROUND 12Z TUE PER MODEL CONSENSUS. THE FIRST OF
THE SHORTWAVES MENTIONED PREVIOUSLY IS PROGGED TO PASS WELL TO OUR
NW AND THEN NORTH AS IT MOVES IT AROUND THE RIDGING FROM SUN NIGHT
INTO MONDAY. FAIRLY CLOSE ON ITS HEELS WILL BE THE NEXT SHORTWAVE
WORKING ACROSS THE PLAINS AND TOWARD THE MID MS VALLEY REGION AND
THEN NORTH OF THE AREA ON TUE. BOTH OF THESE SHOULD BRING JUST SOME
HIGH AND MID CLOUDS FOR THE MOST PART...WITH ANY PRECIP CHANCES WELL
WEST AND NORTH OF THE REGION. RIDING SHOULD THEN REASSERT ITSELF AT
MIDWEEK OVER THE WESTERN GULF AND INTO THE SOUTHEASTERN US...WITH A
RATHER BROAD TROUGH OVER THE WESTERN US AND EAST INTO THE PLAINS. A
SHORTWAVE TROUGH ASSOCIATED WITH THIS BROAD THROUGH SHOULD GRADUALLY
EJECT NORTHEAST TOWARD THE GREAT LAKES ON THU INTO THU NIGHT WITH
RATHER ZONAL FLOW LEFT IN PLACE AT MIDWEEK. THERE ARE TIMING
DIFFERENCES WITH THIS LAST SHORTWAVE AND THE EVOLUTION/STRENGTH OF A
CLOSED LOW OVER THE GREAT LAKES/ONTARIO AREA AT THE END OF THE WEEK.
HOWEVER...YET ANOTHER IN A SERIES OF SFC LOWS TRACKING ACROSS THE
PLAINS AND INTO THE GREAT LAKES REGION IS ANTICIPATED WITH THE
TRAILING RATHER SHEARED OUT BOUNDARY WORKING INTO THE REGION LATE IN
THE PERIOD. THE ECMWF RUNS HAVE BEEN FASTER WITH THIS BOUNDARY OVER
THE PAST FEW RUNS COMPARED TO THE GFS RUN.
SFC RIDGING SHIFTING EAST INITIALLY IN THE PERIOD ALONG WITH SOME
SUBSIDENCE ASSOCIATED WITH HEIGHT RISES SHOULD BE FAVORABLE FOR
RIVER VALLEY FOG ON SUN NIGHT AND A RIDGE/VALLEY TEMP SPLIT. MANY OF
THE VALLEY LOCATIONS...ESPECIALLY EAST SHOULD REACH THE UPPER 30S TO
LOW 40S ON SUN NIGHT. TEMPERATURES WILL CONTINUE TO MODERATE
ASSOCIATED WITH THE RISING HEIGHTS AND SOUTHERLY FLOW ON MON. THE
MODEL CONSENSUS IS CURRENTLY BELOW THE MEX NUMBERS...BUT NUDGED
TEMPS A DEGREE ABOVE THE MODEL CONSENSUS FOR MON. MIN T SHOULD
MODERATE ON MON NIGHT AS WELL...THOUGH A RIDGE/VALLEY SPLIT IS STILL
EXPECTED OVER THE SOUTHEASTERN COUNTIES WITH A SIMILAR MAGNITUDE AS
SUN NIGHT. MIN T ON TUE NIGHT SHOULD BE A COLDER ON AVERAGE COMPARED
TO MON NIGHT WITH THE RIDGE STARTING TO REASSERT ITSELF AND A BIT
LESS CLOUD COVER ON AVERAGE WITH YET ANOTHER IN A SERIES OF
RIDGE/VALLEY TEMP SPLITS. WED NIGHT SHOULD ALSO FAVOR A RIDGE/VALLEY
TEMP SPLIT...BUT THU NIGHT SHOULD FEATURE A MINIMAL OR NO
RIDGE/VALLEY TEMP SPLIT AS THE GRADIENT INCREASES AHEAD OF AN
APPROACHING COLD FRONT. SOME TERRAIN ADJUSTMENTS WERE MADE TO THE
GRID LOAD FOR MIN T FROM MON NIGHT THROUGH WED NIGHT TO REFLECT THE
ABOVE MENTIONED RIDGE/VALLEY TEMP SPLITS.
MAX TEMPS WILL MODERATE FURTHER INTO MIDWEEK AND REMAIN ABOVE NORMAL
THROUGH THE END OF THE PERIOD. MAX TEMPS SHOULD NEAR 15 DEGREES
ABOVE NORMAL ON WED AS 850 MB TEMPS REACH ABOUT THE 12 TO 15C RANGE.
WED IS EXPECTED TO BE THE WARMEST DAY. DURING THE PAST COUPLE OF
WARMER DAYS THE MEX HAS BEEN TOO WARM WITH MAX T AND THE GRID LOAD
TEMPS IN THE UPPER 70S WERE ACCEPTED.
THE ONLY POPS IN THE PERIOD WILL COME AT THE END OF THE PERIOD. IF
THE FASTER ECMWF IS RIGHT OR MODELS TREND TOWARD IT...THEN POPS MAY
NEED TO BE INCREASED ON THU NIGHT. HOWEVER...THE MODEL CONSENSUS
GRID LOAD FAVORED POPS MAINLY ON FRI...AND THIS SEEMED TO BE A
REASONABLE COMPROMISE GIVEN THE MODEL DIFFERENCES NOTED ABOVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 142 AM EDT SAT OCT 20 2012
WITH PERSISTENT CLOUD COVER OVER THE AREA AT AROUND 4 TO 5 KFT...NOT
EXPECTING MUCH FOG DEVELOPMENT TONIGHT. LOCATIONS SUCH AS JKL HAVE
SEEN SOME RAINFALL TODAY WILL SEE A LOWERING OF THE CEILINGS AND A
MVFR CEILING WILL DEVELOP AT JKL BY 10Z AND WILL LIFT BY 13Z. WILL
EXPECT A 4 KFT LAYER TO BE PERSISTENT THROUGH THE DAY TOMORROW WITH A
5 TO 10 KNOT WEST WINDS BEFORE DECOUPLING BY 23Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SHALLENBERGER
LONG TERM....JP
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS GRAY ME
607 PM EDT SAT OCT 20 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE COAST THIS EVENING. HIGH PRESSURE WILL
BUILD TO OUR SOUTH LATE TONIGHT AND SUNDAY. AN UPPER LOW WILL
GRADUALLY EXIT THE REGION ON MONDAY. A FRONT DRAPED ACROSS
SOUTHERN NEW ENGLAND COULD BRUSH THE AREA WITH A FEW SHOWERS
MIDWEEK. ANOTHER SYSTEM MAY IMPINGE ON THE REGION LATE NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
600 PM UPDATE...
ALTHOUGH THE FRONT IS PUSHING THROUGH THE AREA IT IS TAKING ITS
TIME MIXING OUT THE FOG...SO ADDED AN AREA OF PATCHY FOG BASED ON
CURRENT OBSERVATIONS AND LIFTED IT OUT BASED ON THE HRRR FORECAST
MIXING OUT THE FOG AND STRATUS AT ABOUT 02Z. TWEAKED SKY COVER AND
ALSO TEMPERATURES BASED ON THE CURRENT OBSERVATIONS AND TRENDS.
350 PM UPDATE...
STARTING TO SEE SOME CONVECTION IN THE NORTHERN ZONES AND WESTERN
NEW HAMPSHIRE...SO ADDED SLIGHT CHANCE OF A THUNDERSTORM UNTIL 6
PM. THE CONVECTION SHOULD DISSIPATE SHORTLY AFTER SUNSET.
PREVIOUS DISCUSSION...
A FRONT WILL MOVE OFFSHORE BY THIS EVENING AND IN
ITS WAKE A DRIER AIRMASS WILL ADVECT ACROSS THE AREA FROM SW TO NE.
THE FOG OVER COASTAL AND ERN AREAS WILL GRADUALLY BE SWEPT EAST BY
THIS EVENING AS THE WLY WINDS KICK IN BHND THE FROPA. A FEW SHWRS
ARE PSBL ACRS NRN AREAS TNGT OTRW DRY CONDS AND COOLER TEMPS WILL
PREVAIL. THERE SHOULD BE ENOUGH OF A WEST WIND AND MIXING TO
PREVENT ANY FOG FROM DEVELOPING. USED A BLEND OF THE MAV/MET GUID
FOR TEMPS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
AN UPPER TROF CENTERED OVER QUEBEC MOVING NEWD WILL CONTINUE A
CYCLONIC WSWLY FLOW ALOFT WITH A MORE WEST FLOW IN THE LOWER
LEVELS. A FEW INSTBLTY SHWRS OVER THE MTNS ARE PSBL OTRW DRY
DOWNSLOPING WINDS WILL PROVIDE PARTLY TO MOSTLY SUNNY CONDS WITH
HIGH TEMPS MOSTLY IN THE 60S. MORE OF THE SAME IS EXPECTED SUN
NIGHT ONLY DROPPING INTO THE 40S SINCE A LIGHT WLY BREEEZE SHOULD
PERSIST ALLOWING ENOUGH MIXING AND NOT ALLOWING TEMPS TO FALL MUCH
FURTHER. USED A BLEND OF THE MAV/MET GUID.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
SOME UNCERTAINTY IN THE MODELS AS FAR AS TIMING OF LIGHT
PRECIPITATION CHANCES FOR MIDWEEK. NW FLOW PATTERN IN PLACE...WITH
SFC HIGH PRESSURE NOSING FROM THE NORTH. THIS SHOULD RESULT IN A
DECENT N-S TEMPERATURE GRADIENT ACROSS THE NORTHEAST AND SOUTHERN
CANADA. HOWEVER...MODELS DIFFER ON AMPLITUDE OF FLOW AND TIMING OF
ANY SHORT WAVE TROUGH ENERGY. THE 12Z ECMWF IS PRETTY DRY ALL
WEEK. HOWEVER...GFS ENS...OP GFS AND GGEM ALL HINTING AT ONE OR
TWO PERIODS OF SHOWERS RIDING DOWN THE BAROCLINIC ZONE BETWEEN
LATE TUESDAY AND THURSDAY. NOT SOLD ON ANY HIGH POPS AT THIS
TIME...BUT DID CENTER SOME LOW CHANCES OR SLIGHT CHANCES TUESDAY
NIGHT INTO THURSDAY.
THEREAFTER...IT LOOKS LIKE THE CHANCES FOR PRECIPITATION INCREASES
LATE NEXT WEEKEND AS A SYSTEM LOOKS TO EJECT OUT OF THE
PLAINS/LAKES. HOWEVER...IT/S A LONG WAY OUT.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY/...MVFR TO IFR CONDS OVR COASTAL AND
ERN AREAS THRU LATE EVENING BUT IMPROVING TO VFR BY LATER TONIGHT.
ELSEWHR VFR CONDS THRU SUN NIGHT.
LONG TERM...MAINLY VFR DURING THE UPCOMING WEEK. HOWEVER...THERE
COULD BE A FEW BRIEF PERIODS OF MVFR CIGS AND/OR VSBYS TUESDAY
NIGHT INTO WEDNESDAY NIGHT IN LIGHT SHOWERS. AS FAR AS WINDS
GO...SFC GUSTS FROM THE W/NW MONDAY TO 25 KT.
&&
.MARINE...
SHORT TERM...WILL CONTINUE THE SCA BUT ONLY DUE TO SEAS AS WINDS
WILL BE BELOW SCA CRITERIA BUT THE SEAS WILL BE SLOW TO SUBSIDE.
THE SEAS WILL SUBSIDE TO BELOW 5 FT BY MRNG WHILE THE OUTER WATERS
MAY NOT DROP BELOW 5 FT UNTIL SUNDAY EVENING.
LONG TERM...SCA CONDITIONS MONDAY AND MONDAY NIGHT WITH W GUSTS
AROUND 25 KT. THEREAFTER...CONDITIONS SUBSIDE AS HIGH PRESSURE
MOVES IN.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT SUNDAY
FOR ANZ151-153.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT SUNDAY
FOR ANZ150-152-154.
&&
$$
NEAR TERM...KISTNER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1006 AM EDT SAT OCT 20 2012
.SYNOPSIS...
A LARGE UPPER LEVEL LOW CENTER WILL SLOWLY MOVE EASTWARD THROUGH
THE GREAT LAKES TODAY...AND PROVIDE THE UPPER OHIO VALLEY WITH CLOUDS...
SHOWERS AND COOLER TEMPERATURES. HIGH PRESSURE WILL BUILD IN
LATER SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NOT MUCH IN THE WAY OF CHANGES TO THE FORECAST WERE MADE FOR THE
MID-MORNING UPDATE. ONLY SLIGHT ADJUSTMENTS TO TEMPERATURES AS
CLOUDY SKIES WILL MOST LIKELY KEEP TEMPERATURES FOR RISING TOO
MUCH TODAY. OTHERWISE..SCATTERED SHOWERS SHOULD CONTINUE AS THE
UPPER LEVEL SHORTWAVE LIFTS THROUGH THE TROUGH.
PREVIOUS DISCUSSION FOLLOWS...
BLEND OF RECENT SREF AND RAP MODEL OUTPUT...CONFIRMED BY RECENT
SURFACE...RADAR...AND SATELLITE DATA...SHOW AN UPPER LEVEL LOW
WILL ROTATE EASTWARD THROUGH THE GREAT LAKES TODAY...AND CAUSE
CLOUDY SKIES AND SCATTERED SHOWERS ACROSS THE UPPER OHIO VALLEY.
SURFACE WINDS CAN GUST UP TO 25 MPH THIS AFTERNOON.
ANY REMAINING SHOWERS SHOULD DISSIPATE BY MIDNIGHT. CONTINUED TO
FORECAST MOSTLY CLOUDY SKIES...BUT TREND IN RECENT GFS AND NAM MOS
SUGGEST CLOUDS COULD BREAK UP OVERNIGHT. HOWEVER IF THIS
HAPPENS...ITS POSSIBLE THERE CAN BE PATCHY FOG FORMING LATE TONIGHT.
FOR NOW...INCLUDED ISOLATED RIVER VALLEY FOG PATCHES SOUTH AND WEST
OF PITTSBURGH NEAR DAWN SUNDAY.
FORECASTED HIGH TEMPERATURES TODAY AND LOWS TONIGHT TO BE UP TO 5 DEGREES
COOLER THAN NORMAL...PER RECENT GFS AND NAM MOS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
50H LOW WILL PICK UP SPEED AND MOVE ACROSS NEW ENGLAND ON SUNDAY.
ALTHOUGH THE CORE OF THE SYSTEM WILL BE WELL TO THE NORTH...FLOW
IN THE MID AN UPPER LEVELS WILL REMAIN CYCLONIC. BECAUSE OF THE
AFOREMENTIONED FLOW AND COOLER AIR ALOFT...THINK THAT CLOUDS WILL
HOLD AT LEAST INTO SUNDAY AFTERNOON. THE EXTRA CLOUD COVER WILL
ALSO KEEP TEMPS BELOW GUIDANCE.
MID AND LOW LEVEL WAA BEGINS TO INCREASE SUNDAY NIGHT...AND A
SURFACE HIGH WILL MOVE ACROSS THE MID-ATLANTIC. SKIES WILL CLEAR
SUNDAY NIGHT. SFC HIGH WILL MOVE VERY LITTLE ON MONDAY...AS UPPER
LEVEL RIDGE MOVES OVER OHIO. EXPECT SUNSHINE ON MONDAY WITH NEAR
NORMAL TEMPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE MODELS GENERALLY AGREE THAT AN UPPER LEVEL RIDGE WILL BE IN
PLACE OVER MUCH OF THE CENTRAL-EASTERN HALF OF THE US FOR THE START
OF THE PERIOD. WHAT REMAINS A BIT MORE INCONSISTENT ARE THE TIMING
AND STRENGTH OF THE SYSTEMS THAT DEVELOP AND ATTEMPT TO BREAK DOWN
THE RIDGE LATER TUESDAY/WEDNESDAY AND THE TIMING OF THE EVENTUAL
COLD FRONT SUGGESTED BY BOTH THE GFS/ECMWF FOR FRIDAY.
THE GFS TENDS TO BE A BIT FASTER WITH THE WARM-FRONTAL SHOWERS
TUESDAY AFTERNOON/EVENING THAN THE ECMWF...WHICH HAS A STRONGER HIGH
PRESSURE RIDGE AND KEEPS MORE OF THE MOISTURE NORTH. AT THIS
POINT...WILL MAINTAIN A FORECAST CLOSE TO HPC VALUES FOR POPS. BOTH
MODELS AND ENSEMBLE MEANS/MOS GUIDANCE SUGGEST THAT TEMPERATURES
WILL REMAIN 10 DEGREES ABOVE NORMAL THROUGH MUCH OF THE PERIOD UNDER
THE UPPER LEVEL RIDGE AND SOUTHERLY FLOW.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
WITH THE UPPER LOW STILL CENTERED OVER THE GREAT LAKES...PERIODS
OF SHOWERS AND VARIABLE STRATOCUMULUS WILL CONTINUE TO PLAGUE THE
TAF SITES TODAY. PREVAILING MVFR CIGS COULD RAISE TO VFR
OCCASIONALLY THIS AFTERNOON.
SURFACE WINDS WILL BE FROM THE SOUTHWEST AROUND 10 KTS...BUT GUSTS
TO 20-25 KTS ARE POSSIBLE THIS AFTERNOON. WIND SPEEDS WILL LOWER
TO NEAR 5 KTS LATE TONIGHT.
AS UPPER LEVEL LOW CENTER EXITS EAST TONIGHT...THE STRATOCUMULUS
MAY BECOME SCATTERED. HOWEVER...IF THIS HAPPENS...NOCTURNAL
COOLING WILL INCREASE...AND THIS MAY HELP FORM LATE NIGHT MVFR
STRATUS AND FOG.
REGARDLESS OF ANY LATE NIGHT STRATUS/FOG FORMATION...THESE CLOUDS
WILL EITHER DISSIPATE OR LIFT TO VFR CUMULUS BY LATE MORNING...AS
HIGH PRESSURE SUBSIDENCE AND DRYING BEGIN.
.OUTLOOK.../SUNDAY NIGHT THROUGH WEDNESDAY/...
VFR INTO AT LEAST TUESDAY...AND PERHAPS WEDNESDAY DUE TO
UNCERTAINTIES REGARDING TRACK OF NEXT LOW PRESSURE SYSTEM AND ITS
IMPACTS ON THE UPPER OHIO VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
709 AM EDT SAT OCT 20 2012
.SYNOPSIS...
A LARGE UPPER LEVEL LOW CENTER WILL SLOWLY MOVE EASTWARD THROUGH
THE GREAT LAKES TODAY...AND PROVIDE THE UPPER OHIO VALLEY WITH CLOUDS...
SHOWERS AND COOLER TEMPERATURES. HIGH PRESSURE WILL BUILD IN
LATER SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
BLEND OF RECENT SREF AND RAP MODEL OUTPUT...CONFIRMED BY RECENT
SURFACE...RADAR...AND SATELLITE DATA...SHOW AN UPPER LEVEL LOW
WILL ROTATE EASTWARD THROUGH THE GREAT LAKES TODAY...AND CAUSE
CLOUDY SKIES AND SCATTERED SHOWERS ACROSS THE UPPER OHIO VALLEY.
SURFACE WINDS CAN GUST UP TO 25 MPH THIS AFTERNOON.
ANY REMAINING SHOWERS SHOULD DISSIPATE BY MIDNIGHT. CONTINUED TO
FORECAST MOSTLY CLOUDY SKIES...BUT TREND IN RECENT GFS AND NAM MOS
SUGGEST CLOUDS COULD BREAK UP OVERNIGHT. HOWEVER IF THIS
HAPPENS...ITS POSSIBLE THERE CAN BE PATCHY FOG FORMING LATE TONIGHT.
FOR NOW...INCLUDED ISOLATED RIVER VALLEY FOG PATCHES SOUTH AND WEST
OF PITTSBURGH NEAR DAWN SUNDAY.
FORECASTED HIGH TEMPERATURES TODAY AND LOWS TONIGHT TO BE UP TO 5 DEGREES
COOLER THAN NORMAL...PER RECENT GFS AND NAM MOS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
50H LOW WILL PICK UP SPEED AND MOVE ACROSS NEW ENGLAND ON SUNDAY.
ALTHOUGH THE CORE OF THE SYSTEM WILL BE WELL TO THE NORTH...FLOW
IN THE MID AN UPPER LEVELS WILL REMAIN CYCLONIC. BECAUSE OF THE
AFOREMENTIONED FLOW AND COOLER AIR ALOFT...THINK THAT CLOUDS WILL
HOLD AT LEAST INTO SUNDAY AFTERNOON. THE EXTRA CLOUD COVER WILL
ALSO KEEP TEMPS BELOW GUIDANCE.
MID AND LOW LEVEL WAA BEGINS TO INCREASE SUNDAY NIGHT...AND A
SURFACE HIGH WILL MOVE ACROSS THE MID-ATLANTIC. SKIES WILL CLEAR
SUNDAY NIGHT. SFC HIGH WILL MOVE VERY LITTLE ON MONDAY...AS UPPER
LEVEL RIDGE MOVES OVER OHIO. EXPECT SUNSHINE ON MONDAY WITH NEAR
NORMAL TEMPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE MODELS GENERALLY AGREE THAT AN UPPER LEVEL RIDGE WILL BE IN
PLACE OVER MUCH OF THE CENTRAL-EASTERN HALF OF THE US FOR THE START
OF THE PERIOD. WHAT REMAINS A BIT MORE INCONSISTENT ARE THE TIMING
AND STRENGTH OF THE SYSTEMS THAT DEVELOP AND ATTEMPT TO BREAK DOWN
THE RIDGE LATER TUESDAY/WEDNESDAY AND THE TIMING OF THE EVENTUAL
COLD FRONT SUGGESTED BY BOTH THE GFS/ECMWF FOR FRIDAY.
THE GFS TENDS TO BE A BIT FASTER WITH THE WARM-FRONTAL SHOWERS
TUESDAY AFTERNOON/EVENING THAN THE ECMWF...WHICH HAS A STRONGER HIGH
PRESSURE RIDGE AND KEEPS MORE OF THE MOISTURE NORTH. AT THIS
POINT...WILL MAINTAIN A FORECAST CLOSE TO HPC VALUES FOR POPS. BOTH
MODELS AND ENSEMBLE MEANS/MOS GUIDANCE SUGGEST THAT TEMPERATURES
WILL REMAIN 10 DEGREES ABOVE NORMAL THROUGH MUCH OF THE PERIOD UNDER
THE UPPER LEVEL RIDGE AND SOUTHERLY FLOW.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
PER RECENT SURFACE AND RADAR DATA...COUPLED WITH RECENT RAP MODEL
OUTPUT AND GFS LAMP AND NAM MOS...EXPECT MAINLY MVFR
STRATOCUMULUS CEILINGS TODAY. VISIBILITIES MAY BRIEFLY BECOME MVFR
IN PASSING SCATTERED SHOWERS.
SURFACE WINDS WILL BE FROM THE SOUTHWEST AROUND 10 KTS...BUT GUSTS
TO 20-25 KTS ARE POSSIBLE THIS AFTERNOON. WIND SPEEDS WILL LOWER
TO NEAR 5 KTS LATE TONIGHT.
AS CAUSATIVE UPPER LEVEL LOW CENTER EXITS EAST TONIGHT...THE
STRATOCUMULUS MAY BECOME SCATTERED. HOWEVER...IF THIS
HAPPENS...NOCTURNAL COOLING WILL INCREASE...AND THIS MAY HELP FORM
LATE NIGHT MVFR STRATUS AND FOG.
REGARDLESS OF ANY LATE NIGHT STRATUS/FOG FORMATION...THESE CLOUDS
WILL EITHER DISSIPATE OR LIFT TO VFR CUMULUS BY LATE MORNING...AS
HIGH PRESSURE SUBSIDENCE AND DRYING BEGIN.
.OUTLOOK.../SUNDAY NIGHT THROUGH WEDNESDAY/...
VFR INTO AT LEAST TUESDAY...AND PERHAPS WEDNESDAY DUE TO
UNCERTAINTIES REGARDING TRACK OF NEXT LOW PRESSURE SYSTEM AND ITS
IMPACTS ON THE UPPER OHIO VALLEY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
949 PM MDT SUN OCT 21 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
UPDATED THE FORECAST TO RAISE OVERNIGHT TEMPERATURES ACROSS MY SE
FOR TONIGHT. ALSO ADJUST CLOUD COVER AND LEFT THE POPS AS CHANCE
POPS ACROSS THE YELLOWSTONE VALLEY. DROPPED POPS ACROSS MY
WESTERN ZONES. PACIFIC MOISTURE IS CURRENTLY BE PUSHED ACROSS
WYOMING AND INTO EASTERN MONTANA BY A FAST MOVING JET STREAK.
WEAK SURFACE CIRCULATION IS TRYING TO DEVELOP ON THE WESTERN SIDE
OF THIS MOISTURE PLUME. THE PROBLEM IS THIS PLUME IS NOW TO FAR TO
THE EAST AND THE SURFACE CIRCULATION WOULD HAVE TO BE STRONG
ENOUGH TO STEER THIS IN A MORE NORTHERLY DIRECTION TO REALLY IMPACT
ALL OF OUR CWA THE WAY THE NAM IS SHOWING. IT LOOKS TO ME THAT
MOST OF THE PRECIPITATION WILL FALL ACROSS THE YELLOWSTONE VALLEY
AND EAST OF WOLF POINT TONIGHT INTO TOMORROW MORNING. ALSO EXPECT
THE PRECIPITATION TO BE FAIRLY LIGHT BETWEEN .10TH AND.15TH OF AN
INCH. THE LATEST HRRR AGREES WITH THIS ASSESSMENT. REST OF THE
SHORT TERM LOOKS GOOD. RSMITH
PREVIOUS DISCUSSION...AN UPPER-LEVEL LOW PRESSURE SYSTEM CENTERED
OVER NORTHERN SASKATCHEWAN AND A DEVELOPING LOW OFFSHORE OF THE
PACIFIC NORTHWEST WILL BE THE MAIN FEATURES DRIVING THE WEATHER
OVER THE NEXT COUPLE OF DAYS. SOUTHWEST FLOW HAS SET UP OVER THE
REGION DUE TO THE POSITION OF THE LOW PRESSURE SYSTEM IN CANADA
AND AS A RESULT MID-LEVEL CLOUDS HAVE STREAMED ACROSS PORTIONS OF
EASTERN MONTANA TODAY.
NOW THROUGH TUESDAY THE UPPER LOW IN SASKATCHEWAN WILL RETROGRADE
AND WEAKEN WHILE THE DEVELOPING LOW PRESSURE SYSTEM OVER THE
PACIFIC WILL DEEPEN AS PUSHES ONSHORE. SHORT WAVE ENERGY WILL FIRE
ACROSS THE REGION FROM THIS APPROACHING SYSTEM. SHOWERS WILL
DEVELOP ON MONDAY AHEAD OF A COLD FRONT THAT WILL PUSH THROUGH ON
TUESDAY.
A MIX OF RAIN AND SNOW WILL BE POSSIBLE NORTH OF THE MISSOURI
RIVER AND ALSO FOR A FEW AREAS WITH THE HIGHER ELEVATIONS SOUTH OF
THE RIVER. AT THIS TIME TOTAL MOISTURE ACROSS NORTHEAST FOR MONDAY
AND TUESDAY MAY BE UP TO 0.25 INCH. SNOW ACCUMULATION...IF
ANY...IS EXPECTED TO BE LIGHT. AES
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
GOING FORECAST WAS IN GOOD SHAPE WITH ONLY TWEAKS MADE TO TEMPS
TUESDAY NIGHT-WEDNESDAY NIGHT AND WINDS (TO HELP WITH COORDINATION).
JAMBA
PREVIOUS DISCUSSION...
THE MODELS IN THE EXTENDED ARE STILL HAVING ISSUES WITH THE UPPER
LOW PROJECTED AT THE START OF THE FORECAST PERIOD ON 00Z WED WHICH
IS LOCATED OVER SOUTHERN ALBERTA. THE GFS DEEPENS THE UPPER LOW
OVER CENTRAL SASKATCHEWAN... WHEREAS THE EC/GEM MOVES THE SYSTEM
TO THE NORTHWEST FASTER. LOOKED AT THE ENSEMBLES FOR THE GFS AND
EC...AND THEY HOLD MOSTLY TO THEIR OPERATIONAL SOLUTIONS...WHICH
MAKES FOR A HARD FORECAST FOR NORTHEAST MONTANA THROUGH THE
EXTENDED.
WILL STAY WITH THE TREND OF SLIGHT CHANCE TO CHANCE POPS OF SNOW
WITH A LITTLE RAIN MIXED IN DURING THE DAYTIME THROUGH THE
FORECAST. ALL GUIDANCE RUNS HAS TEMPERATURES WELL BELOW NORMAL
THROUGH THE PERIOD THEREFORE WILL MAINTAIN THE FORECAST FOR THE
COOLEST TEMPERATURES OF THE FALL SEASON. PROTON
&&
.AVIATION...
LATE AFTERNOON UPDATE...
VFR INITALLY... DECREASING TO MVFR CEILINGS DURING THE MORNING.
TEMPORARY IFR POSSIBLE MONDAY.
CLOUD COVERAGE WILL INCREASE THIS EVENING AS A STORM SYSTEM
APPROACHES. CEILINGS WILL THEN BEGIN TO SLOWLY LOWER TO MVFR
THROUGH THE MORNING HOURS ON MONDAY.
RAIN WILL ALSO BEGIN TO COVER THE AREA AFTER MIDNIGHT WITH
TEMPORARY OBSCURATION TO VISIBILITIES AND IFR CEILINGS POSSIBLE WITH
STRONGER SHOWERS.
WINDS WILL BE OUT OF THE EAST AND LIGHT THIS EVENING INCREASING TO
AROUND 10 KTS BY TOMORROW AFTERNOON. GAH
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
624 PM CDT SUN OCT 21 2012
.AVIATION...00Z TAF. LOTS OF ISSUES THIS FORECAST PERIOD AND THE
POTENTIAL FOR THINGS GOING OFF THE BEATEN PATH IS PRETTY STRONG.
SAGGING FRONTAL BOUNDARY HAS JUST CLEARED KGRI...BUT NOT AURORA
OR HASTINGS. DEWPOINT DROPPED ABOUT 10 DEGREES LAST HOUR OR SO.
LOW LEVEL MOISTURE STREAM FROM THE SOUTHEAST HAS RESULTED IN A
SCATTERED TO BROKEN DECK OF CLOUDS...WHICH LOOK LIKE THEY WILL
INFILTRATE THE KGRI AREA THE NEXT FEW HOURS. LATER TONIGHT...
MOST MODELS ARE BULLISH WITH EXTENSIVE LOW CLOUDS NEAR AND
SOUTHEAST OF THE FRONT...AS WELL AS SOME WEAK BUT BROAD ISENTROPIC
LIFT JUST EAST OF KGRI. THAT COULD SPARK SOME MID LEVEL TYPE
SPRINKLES BUT IT APPEARS BEST RAIN SHOT WILL BE EAST OF KGRI.
IT SHOULD RESULT IN FAIRLY WIDESPREAD AND GRADUALLY LOWERING OF
CEILINGS AS SEEN ON THE HRRR THROUGH THE NIGHT. NAM IS AGGRESSIVE
IN KEEPING LOW CLOUDS AROUND MUCH OF THE DAY MONDAY...A SECOND
ROUND OF WHICH ACTUALLY PULLS SOUTH POST FRONTAL FROM NORTHERN
NEBRASKA. HAVE KEPT A PESSIMISTIC VIEW FOR THE TAF WITH MOSTLY
MVFR CONDITIONS FROM LATER TONIGHT THROUGH MIDDAY MONDAY.
&&
.PREV DISCUSSION... /ISSUED 344 PM CDT SUN OCT 21 2012/
SHORT TERM...TONIGHT THROUGH MONDAY. PATTERN ALOFT FEATURED UPPER
LOW PRESSURE SYSTEMS OFF OF BRITISH COLUMBIA...IN SASKATCHEWAN AND
QUEBEC...WITH SOUTHWEST FLOW ACROSS MUCH OF THE WESTERN/CENTRAL
CONUS. A SHORTWAVE TROUGH WAS LIFTING INTO ARIZONA...WHILE
ADDITIONAL SHORTWAVE ENERGY WAS LIFTING OUT AHEAD OF THIS SYSTEM IN
CO/OK. MAIN JET WAS ORIENTED FM THE PACIFIC NORTHWEST ACROSS THE
NORTHERN PLAINS/DAKOTAS. AT THE SURFACE...LOW PRESSURE STRETCHED FM
SW KANSAS TO NORTHWEST IOWA...WITH SURFACE TROUGH/COOL FRONTAL
BOUNDARY ORIENTED FM KBVN TO KMCK TO GLD EARLY THIS AFTN. AHEAD OF
THE FRONT...MOISTURE WAS MIGRATING NORTH FM CENTRAL/EASTERN KS NORTH
INTO NEB. SFC DPS HAD RISEN INTO THE LOW 60S IN KS/FAR SOUTHERN
NEB. WHILE BEHIND THE FRONT...DPS WERE THE UPPER 30S/NEAR 40F.
WEAK SFC FRONT WILL SLOWLY MIGRATE SOUTHEASTWARD TONIGHT AS SFC LOW
DEEPENS IN SOUTHERN KS AND AND LOW EDGES EASTWARD AND LIFTS NORTH
ALONG THE FRONT. MOISTURE WILL POOL ALONG AND AHEAD OF THE
BOUNDARY...AND WILL AID IN DEVELOPMENT OF LOW CLOUDS/STRATUS
TONIGHT...SIMILAR TO EARLIER THIS MORNING IN KS. IN ADDITION...NOT
OVERLY DRY CONDITIONS EXIST BEHIND THE FRONT AND STRATUS DEVELOPMENT
WAS ALSO NOTED ACROSS PORTIONS OF THE NEB PANHANDLE THIS MORNING.
AS WE HEAD INTO TONIGHT AFTER DARK...CLOUD COVER WILL BE ON THE
INCREASE INITIALLY ACROSS OUR EASTERN ZONES...BUT THEN WILL SETTLE
IN BEHIND THE FRONT IN OUR NORTHWEST ZONES AS WELL. IN RICHER
MOISTURE IN OUR EASTERN ZONES AND WHERE WINDS WILL BE LIGHT ALONG SFC
TROUGH AXIS...CONDITIONS WILL BE FAVORABLE FOR FOG DEVELOPMENT WHICH
MAY BECOME DENSE AT TIMES. WILL INCLUDE FOG IN FCST WITH VSBYS
BELOW A MILE AND MONITOR TRENDS FOR FURTHER VSBY REDUCTIONS. SREF
VSBY PROBS ALSO INDICATE A 50 PCNT CHC OR SO FOR VSBYS BELOW ONE
MILE IN OUR SOUTHEAST COUNTIES...WITH EVEN HIGH PROBS OF VSBYS BELOW
THREE MILES.
ALSO TONIGHT...LIFT INCREASES AHEAD OF MID LEVEL SHORTWAVE LIFTING
ACROSS THE CENTRAL PLAINS. GOOD MID LEVEL WAA IS PROGGED FM OUR FAR
EASTERN CWA ACROSS EASTERN KS/NEB...AND THE LLVL JET STRENGTHENS TO
AROUND 40KTS. THE ORIENTATION OF THE LLVL JET IS PRIMARILY ACROSS
EASTERN NEB/KS AND POINTS EASTWARD WITH OUR FAR EASTERN ZONES ON THE
PERIPHERY OF THIS MAIN LIFT. WITH BOUNDARY ACROSS OUR EASTERN
CWA...AND MOISTURE IN PLACE...MUCAPES INCREASE TO OVER 1000 J/KG IN
OUR EASTERN CWA AND CANNOT RULE OUT AN ISOLATED STORM IN OUR EASTERN
ZONES LATER TONIGHT OR INTO MONDAY MORNING UNTIL FRONT PUSHES
FARTHER EAST. FCST SOUNDING SUGGEST LLVL MOISTURE WILL DEEPEN ABOVE
H85 IN PORTIONS OF OUR EAST/NORTHEAST ZONES AND WITH THE INCREASING
LIFT OVER THE MOISTURE...COULD SEE GENERATION OF DRIZZLE ALSO AND
WILL INCLUDE POTENTIAL FOR THIS AS WELL.
POTENTIAL FOR A TSTM/DRIZZLE/FOG/STRATUS LINGER INTO THE MORNING
HOURS ON MONDAY...THEN CLOUDS WILL BEGIN TO DECREASE WEST/EAST DURING
THE DAY. HAVE SOME CONCERNS THAT MODELS MAY BE ATTEMPTING TO BREAK
UP LOW CLOUDS TOO QUICKLY...ESPECIALLY IN OUR EAST AS FRONT BEGINS
TO WASH VS SWEEP EAST AND LLVL MOISTURE LINGERS INTO AFTN. WITH
THIS IN MIND...WILL TREND TEMPS COOLER FOR MONDAY MAXES.
LONG TERM...MONDAY NIGHT THROUGH SUNDAY. FORECAST CONCERNS CENTER
AROUND FOG MONDAY NIGHT...EXTENT OF TEMPERATURE RISES ON
TUESDAY...TIMING OF COLD FRONTAL PASSAGE ON WEDNESDAY...AND THEN
POST FRONTAL TEMPERATURES AND PRECIPITATION CHANCES WEDNESDAY NIGHT
ONWARD.
MONDAY NIGHT INTO TUESDAY. THE 12Z NAM AND SREF SHORT RANGE
ENSEMBLES ARE INDICATING A DECENT CHANCE OF FOG LATE MONDAY NIGHT
INTO TUESDAY MORNING WITH A WARM FRONT IN THE AREA. THE WARM FRONT
WILL TRY TO LIFT NORTH ACROSS THE CWA DURING THE DAY ON TUESDAY.
KANSAS ZONES SHOULD BE SOUTH OF THIS WARM FRONT AND WILL LIKELY SEE
HIGHS IN THE 80S. THE TEMPERATURE FORECAST ACROSS NEBRASKA IS LESS
CERTAIN WITH SOME MODELS SHOWING THE WARM FRONT STALLING ACROSS OUR
NORTHERN CWA...WHILE OTHER MODELS WASH THE FRONT OUT. THE POSSIBLE
PRESENCE OF CLOUDS WILL BE ONE OF THE BIG FACTORS TO WATCH OUT FOR.
CLOUDS WILL MORE THAN LIKELY CLEAR DURING THE DAY ON TUESDAY ACROSS
KANSAS...BUT MAY STRUGGLE TO BREAK UP ACROSS SOME NEBRASKA
ZONES...ESPECIALLY NORTHEASTERN ZONES. OVERALL THIS SHOULD STILL BE
ONE OF THE NICER DAYS OF THE WEEK WITH HIGHS RANGING FROM THE UPPER
70S NORTH TO THE LOWER 80S OVER KANSAS.
WEDNESDAY...THE 12Z NAM...12Z GFS...AND 12Z ECMWF ARE ALL IN PRETTY
GOOD AGREEMENT IN BRINGING THE STRONG COLD FRONT INTO OUR CWA DURING
THE DAY ON WEDNESDAY. THE FRONT IS SLOW MOVING AND MAY NOT EXIT OUR
SOUTHEAST CWA UNTIL WEDNESDAY NIGHT. THERE WILL LIKELY BE A SHARP
TEMPERATURE GRADIENT ACROSS OUR CWA WEDNESDAY WITH HIGHS RANGING
FROM THE LOWER 60S OVER OUR NORTHEAST WHERE THE FRONT COULD PASS
THROUGH IN THE MORNING...TO THE LOWER 80S OVER OUR SOUTHEAST ZONES
WHERE THE FRONT SHOULD NOT PASS THROUGH UNTIL AFTER SUNSET WEDNESDAY
EVENING. PRECIPITATION IS CURRENTLY NOT EXPECTED WITH THE WEDNESDAY
FRONTAL PASSAGE BUT MAY BE POSSIBLE LATER WEDNESDAY NIGHT BEHIND THE
FRONT AS A SHORT WAVE VORT MAX PUSHES THROUGH. FORECAST MODELS ARE
SPLIT ON WHETHER OR NOT WE WILL SEE ANY PRECIPITATION WEDNESDAY
NIGHT...AND THOSE THAT INDICATE PRECIPITATION TEND TO SHOW IT BEING
JUST A LIGHT RAIN WITH VERY MINOR ACCUMULATION IF ANY.
THURSDAY THROUGH FRIDAY...MUCH COOLER AIR WILL CONTINUE TO FILTER
INTO THE REGION WITH HIGHS ON THURSDAY IN THE 40S AND 50S...WITH
PRIMARILY 40S BY FRIDAY. AM CONCERNED THAT WE MIGHT BE TOO WARM WITH
OUR FORECAST...ESPECIALLY IF WE END UP SEEING LIGHT PRECIPITATION.
WOULD NOT BE SURPRISED IF SOME OF OUR NORTHWEST ZONES END UP BEING
STUCK IN THE UPPER 30S ON FRIDAY. THE NEW 12Z ECMWF QUICKLY ENDS
PRECIPITATION CHANCES THURSDAY MORNING...WHILE THE GFS AND CANADIAN
LINGER PRECIPITATION CHANCES INTO FRIDAY. THIS IS SIGNIFICANT AS THE
TEMPERATURES WILL BE COLD ENOUGH BY THURSDAY NIGHT AND FRIDAY TO
SUPPORT SNOW AS A POTENTIAL PRECIPITATION TYPE. 850MB TEMPERATURES
ON FRIDAY RANGE FROM AROUND -3C TO -7C ACROSS THE CWA DEPENDING ON
WHICH MODEL YOU LOOK AT. THE MAIN POINT BEING THAT ALL MAJOR
DETERMINISTIC MODELS HAVE OUR CWA BELOW FREEZING JUST OFF THE SFC.
THE CHANCE OF SEEING ANY PRECIPITATION IS RATHER LOW...BUT SHOULD WE
SEE PRECIPITATION...IT MAY BE A LITTLE MORE LIKELY TO BE SNOW RATHER
THAN RAIN...AND OUR HIGH TEMPERATURES WOULD ALSO BE A BIT COOLER
THAN CURRENTLY FORECAST IF THAT SHOULD HAPPEN.
SATURDAY AND SUNDAY...EXPECT DRY WEATHER BY THE WEEKEND BUT
CONTINUED VERY COOL FOR THIS TIME OF YEAR WITH HIGHS IN THE 40S ON
SATURDAY AND THEN 40S TO LOWER 50S ON SUNDAY.
AVIATION...18Z TAF. SFC TROUGH/COOL FRONTAL BOUNDARY WAS SAGGING
SOUTH INTO CENTRAL NEB EARLY THIS AFTN...AND THE FRONT WILL CONTINUE
TO SINK SOUTH THRU TONIGHT...WITH LIGHT SOUTHEASTERLY WINDS
GRADUALLY SHIFTING EAST...NORTHEAST AND NORTHERLY. LOWLEVEL
MOISTURE WILL WORK NORTH FM CENTRAL/EASTERN NEB INTO PORTIONS OF
CENTRAL AND EASTERN NEB TONIGHT WHILE ADDITIONAL MOISTURE SETTLES
IN BEHIND THE FRONT AS WELL. THIS WILL LEAD TO PREVALENT CLOUD
COVER INTO THE OVERNIGHT PERIODS AND INTO THE MORNING HOURS ON
MONDAY. LIFT INCREASES AS A MID LEVEL SHORTWAVE TROUGH LIFTS
ACROSS THE CENTRAL PLAINS TONIGHT AND THE LLVL JET TO NEAR 40KTS.
KGRI IS ON THE WESTERN PERIPHERY OF THE BETTER DYNAMICS AND IT
LOOKS LIKE BETTER CHCS FOR DZ OR LIGHT PCPN WILL FOCUS EAST OF THE
TERMINAL. WILL KEEP KGRI DRY BUT WITH THE INCREASING MOISTURE WILL
DROP CIGS OVERNIGHT INTO LIFR CATEGORY. WINDS MAY REMAIN STEADY
ENOUGH TO HOLD UP VSBYS BUT CONFIDENCE IS NOT HIGH WITH VFR VSBYS
AND WILL INCLUDE POTENTIAL FOR LIFR VSBY IN BR ALSO.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 AM EDT SAT OCT 20 2012
.SYNOPSIS...
DRY HIGH PRESSURE WILL BUILD INTO THE CAROLINAS FROM THE WEST OVER
THE WEEKEND AND PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 1005 PM FRIDAY...
THE LEAD LOW LEVEL FRONTAL ZONE HAD MOVED JUST EAST OF THE NC OUTER
BANKS AT 02Z...WHILE A REINFORCING COLD FRONT HAD MOVED TO THE
VICINITY OF THE BLUE RIDGE. THIS TRAILING/REINFORCING COLD FRONT
WILL PRODUCE A BRIEF PERIOD OF LOW LEVEL CAA IN THE WEST TOWARD
DAYBREAK...THEN FOR A FEW HOURS SHORTLY THEREAFTER ACROSS THE
REMAINDER OF CENTRAL NC. OTHERWISE...THE NIGHT WILL BE CLEAR WITH
ALTERNATING PERIODS OF CALM AND SOUTHWESTERLY STIRRING IN ADVANCE OF
THE TRAILING FRONT...WHICH WILL RESULT IN CONTINUED WIDE-RANGING AND
VARIABLE TEMPERATURES -- HIGHLIGHTED AT 02Z BY 45 DEGREES AT K5W8
AND A PAIR OF 60S AT KINT AND KFAY -- OVERNIGHT. PROVIDED EVERYONE
HAS AT LEAST A BRIEF PERIOD OF CALM AS EXPECTED...LOWS WILL BOTTOM
IN THE 41 TO 48 DEGREE RANGE. -MWS
AS OF 220 PM FRIDAY...
THE COLD FRONT EXTENDING SOUTH FROM THE OCCLUDED LOW OVER THE GREAT
LAKES HAS BEEN MOVING VERY SLOWLY ACROSS THE CWA TODAY...STRUGGLING
TO GET PAST US HWY 1 THROUGH NOON. HOWEVER...DEWPOINTS ARE FINALLY
BEGINNING TO MIX OUT MORE EFFICIENTLY BEHIND THE FRONT...AND THE
SHARP DEWPOINT/INSTABILITY GRADIENT IS SHIFTING EAST INTO THE
COASTAL PLAIN. DRIER AIR ALOFT NOTED IN WATER VAPOR IMAGERY IS
LIMITING CUMULUS DEVELOPMENT TO A NARROW STRIP ALONG A REGION
CONFLUENCE FROM LEXINGTON TO ROXBORO. HRRR RUNS HAVE BEEN SHOWING A
FEW ISOLATED SHOWERS OVER THE NORTHERN PIEDMONT AFTER 20Z...BUT THIS
SEEMS OVERDONE GIVEN THE AMOUNT OF DRY AIR ALOFT.
OTHERWISE...SOUTHWESTERLY WIND GUSTS ARE STARTING TO
DEVELOP...MOSTLY IN THE TEENS THUS FAR...BUT A FEW MAY REACH 20-25KT
BEFORE SUNSET.
TONIGHT...
A SHORTWAVE IN THE BASE OF THE UPPER TROUGH WILL SWING ACROSS
GA/SC...WITH CONTINUED DRY CONDITIONS AND MOSTLY CLEAR SKIES ACROSS
CENTRAL NC. A LIGHT WESTERLY WIND MAY LIMIT FULL RADIATIONAL
COOLING...MID TO UPPER 40S WEST TO EAST.
SATURDAY AND SATURDAY NIGHT...
BROAD CYCLONIC UPPER LEVEL FLOW WILL CONTINUE OVER THE AREA AS THE
GREAT LAKES UPPER LOW BEGINS TO OPEN UP AND LIFT NORTHEAST. A
SPEED MAX DIVING THROUGH THE BACK SIDE OF THE UPPER TROUGH WILL
SHARPEN THE TROUGH AXIS AS IT CROSSES THE AREA SATURDAY EVENING.
THE ADDED DPVA MAY BE ENOUGH TO HELP ENHANCE SOME LATE AFTERNOON
CLOUD COVER AS RH CROSS SECTIONS SHOW A LAYER OF MOISTURE AT THE TOP
OF THE BOUNDARY LAYER (5-8KT FT). WITH WEAK THERMAL ADVECTION/FLOW
AHEAD OF THE TROUGH AXIS...WILL USE 1000-850MB THICKNESSES FOR
HIGHS...YIELDING UPPER 60S TO LOWER 70S.
ONCE THE TROUGH AXIS MOVES EAST...NORTHWESTERLY FLOW WILL DEVELOP
ALOFT SATURDAY NIGHT. THIS TYPE OF PATTERN SUGGESTS THE POTENTIAL
FOR OROGRAPHIC CIRRUS...ALTHOUGH THE NAM/GFS SHOW THE BEST UPPER
LEVEL MOISTURE DIVING JUST SOUTH OF THE APPALACHIANS. WITHOUT
CIRRUS...THE ARRIVAL OF BETTER LOW LEVEL COLD ADVECTION BEHIND THE
TROUGH AXIS SHOULD LEAD TO LOWS IN THE LOW TO MID 40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 230 PM FRIDAY...
CLOSED UPPER LOW AND ASSOCIATED UPPER TROUGH OVER THE EASTERN US
WILL LIFT NORTHEASTWARD INTO SOUTHEASTERN CANADA DURING THE DAY ON
SUNDAY...WITH STRONG SYNOPTIC SCALE SUBSIDENCE SETTLING OVER THE
REGION IN IT WAKE AS THE UPSTREAM RIDGE OVER THE CENTRAL US
SHIFTS EASTWARD INTO THE AREA. THIS WILL RESULT IN CONTINUED DRY
CONDITIONS WITH A RAPID WARM-UP/MODERATION FROM BELOW NORMAL
DAYTIME TEMPERATURES IN THE MID TO UPPER 60S ON SUNDAY TO
ABOVE NORMAL READINGS IN THE LOWER TO MID 70S BY MONDAY. STRONG
RADIATIONAL COOLING AND A DRY AIRMASS IN PLACE WILL STILL ALLOW FOR
CHILLY MORNING LOWS BOTH MORNINGS. LOWS IN THE LOWER TO MID 40S.
&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...
BROAD SUBTROPICAL RIDGING WILL ENVELOP THE SOUTHEASTERN/EASTERN US
THROUGH THE UPCOMING WORK WEEK...DOWNSTREAM OF THE WESTERN/CENTRAL US
TROUGH. WHILE THERE ARE SOME GROSS DIFFERENCES WITH HOW NWP MODELS
HANDLE THE EVOLUTION OF THE WESTERN US TROUGH AND ASSOCIATED REX
BLOCK...CENTRAL NC LOOKS TO BE WELL UNDER THE INFLUENCE OF THE
SUBTROPICAL RIDGE TO CLOSE THE WORK WEEK...KEEPING SHORTWAVE
DISTURBANCES AT ARMS LENGTH...TRACKING NORTHEAST THROUGH THE
PLAINS...THROUGH THE THE GREAT LAKES AND THEN INTO SOUTHEASTERN
CANADA.
THIS WILL RESULT IN WARM AND QUITE WEATHER CONDITIONS("INDIAN
SUMMER")THROUGH THE WEEK. DAYTIME HIGHS WELL IN THE MID TO UPPER 70S.
LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 200 AM SATURDAY...
24-HR TAF PERIOD:
VFR CONDITIONS WILL RULE THROUGH THE TAF PERIOD IN ASSOC/W A DRY
AIRMASS IN PLACE IN THE WAKE OF A RECENT COLD FRONTAL PASSAGE. ASIDE
FROM SCATTERED DIURNAL CU AT 5-6 KFT AGL AT THE INT/GSO TAF SITES
THIS AFTERNOON...CLEAR SKIES WILL PREVAIL. LIGHT/VARIABLE WINDS AT
~5 KT WILL BECOME WESTERLY AT 5-10 KT THIS AFTERNOON...THEN
NORTHWEST AT ~5 KT AFTER SUNSET.
LOOKING AHEAD:
SURFACE HIGH PRESSURE ANCHORED OVER THE CAROLINAS WILL RESULT IN
DRY/VFR CONDITIONS THROUGH EARLY TO MID NEXT WEEK. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...MWS/BLS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...VINCENT
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
828 PM CDT SUN OCT 21 2012
.DISCUSSION...TEMPERATURES WILL BE THE MAIN CHALLENGE TONIGHT.
AREAS ACROSS THE NORTHERN FA ARE CURRENTLY BELOW THE EXPECTED
DIURNAL CURVE. THIS AREA SHOULD REMAIN UNDER THE INFLUENCE OF
SURFACE HIGH PRESSURE THROUGH THE NIGHT. THE BIGGEST UNKNOWN IS
HOW HIGH CLOUDS WILL AFFECT THE TEMPERATURE DROP. AS OF
8PM...THESE CLOUDS DO NOT APPEAR TO BE HAVING MUCH AFFECT AT ALL.
WILL LOWER MIN TEMPS ACROSS THE NORTHERN FA ABOUT 5F...LEAVING THE
SOUTHERN FA ALONE. USED THE 22Z HRRR AS A GUIDE.
&&
.AVIATION...VFR CONDITIONS THRU MON AFTN EXPECTED. LOOKS LIKE
CONSIDERABLE HIGH AND MID LEVEL MOISTURE TO CONTINUE TO MOVE
NORTHEAST ACROSS THE AREA THROUGH MONDAY AFTN...THOUGH SOME CLEAR
AREAS WILL BE FOUND. WINDS WILL BE NORTH-NORTHWEST TONIGHT 10 KTS
OR LESS AND THEN GRADUALLY TURN TO THE NORTHEAST AND THEN EAST ON
MONDAY.
&&
.PREV DISCUSSION... /ISSUED 300 PM CDT SUN OCT 21 2012/
SHORT TERM...
KIND OF AN UNSETTLED PERIOD COMING UP WITH NUMEROUS CHANCES FOR
LIGHT RAIN. NOT SEEING GREAT AGREEMENT BETWEEN THE MODELS SO WILL
TRY NOT TO DEVIATE TOO FAR FROM CONTINUITY.
TONIGHT...SPRINKLES OR VERY LIGHT RAIN PRETTY WELL TAPERING OFF
LATE THIS AFTERNOON BUT QUITE A BIT OF CLOUD COVER LINGERS. PRETTY
STRONG UPPER JET OVER THE REGION HELPING TO KEEP THESE LIGHT
SHOWERS GOING. 12Z GFS KEEPS SOME OF THESE GOING TONIGHT BUT WILL
STICK WITH THE DRY ROUTE FOR NOW. COULD VERY WELL BE VIRGA. SOME
CLEARING IS WORKING INTO THE NORTHWEST FA NOW AND LOWS UP IN THIS
AREA COULD BE PROBLEMATIC. THINK THERE WILL BE SOME INCREASING
CLOUD COVER AGAIN LATE SO TEMPS COULD FALL THIS EVENING WITH SOME
STEADYING OFF LATER.
MON-WED...DO NOT HAVE A GOOD FEEL FOR PCPN ARRIVAL AGAIN ON
MONDAY. MOST MODEL SOLUTIONS KEEP ANY WEST OF THE RED RIVER VALLEY
IN THE MORNING BUT DIFFER BY AFTERNOON. EITHER WAY ANY PCPN WOULD
STILL BE ON THE LIGHT SIDE. MUCH BETTER MODEL AGREEMENT BY MON
NIGHT WHICH ALSO HAS GOOD CONTINUITY IN DEPICTING MUCH BETTER
PCPN CHANCES IN THE NORTHWEST FA. THESE BETTER CHANCES FOR PCPN
SHOULD LINGER ACROSS THE NORTHERN FA INTO TUE THEN INTO THE NE FA
TUE NIGHT. ANOTHER STRONG JET AND LOW LIFT UP INTO THE FA ON WED
WHICH SHOULD INCREASE PCPN CHANCES AGAIN THIS TIME ACROSS THE
SOUTHEAST FA. BUMPED UP PCPN CHANCES INTO THE LIKELY REALM.
LONG TERM (WED NIGHT-SUN)...
MAIN ISSUE WILL BE STORM POTENTIAL ON THURSDAY. MAY DAYS AGO THE
GFS MODEL WAS INDICATING A PRETTY GOOD STORM FOR ERN ND/NW MN ON
THURSDAY...SINCE THEN IT HAS BACKED OFF OVER THE LAST SEVERAL RUNS.
THE 00Z 10/21 MODEL PACKAGE CAME IN WITH 00Z ECMWF AND 00Z GEM WITH
NOW SHOWING A PRETTY GOOD STORM FOR OUR AREA WITH SFC LOW MOVING TO
DULUTH THEN INTO ONTARIO AND ENOUGH COLD AIR TO THE WEST FOR
ACCUMULATING SNOWS OVER ERN ND INTO PARTS OF NW MN. THE 00Z AND 06Z
GFS WASNT AS GUNG-HO AND WAS FLATTER AND WEAKER WITH WAVE. 12Z
MODEL SUITE SHOWS GFS TURNING A BIT TOWARD STRONGER SOLN...BUT STILL
WEAKER AND FARTHER EAST WITH LOW BUT NOT AS WEAK AS PREV RUNS AND
12Z GEM BACK TO BEING SIMILAR...WEAK AND FARTHER EAST. 12Z ECMWF
RUN IS PRETTY CONSISTENT FROM ITS 00Z RUN IN SHOWING SFC LOW
DEVELOPING FROM SW MINNESOTA INTO NORTHEAST MINNESOTA THURSDAY AND
THEN INTO ONTARIO FRIDAY WITH ENOUGH COLD AIR FOR A SWATH OF SNOW
ACROSS MUCH OF ERN ND INTO NW MN. SO...STILL SOME MODEL DIFFERENCES
BUT ALL SIGNS POINT TO SOME PRECIP POTENTIAL WED NIGHT INTO THURSDAY
OF SOME DEGREE. USING A BIT COLDER REGIME FROM ALL BLEND WOULD HAVE
TEMPS IN BTWN COLDER EURO AND WARMER GFS AND TRENDED PRECIP AS
MOSTLY LIQUID WED NIGHT TO A MORE MIX THURSDAY TO MOSTLY -SN
THURSDAY NIGHT. UPPER LOW THAT DEVELOPS DUE TO STORM IN CNTRL
MANITOBA-NW ONTARIO TO KEEP AT LEAST NRN FCST AREA IN SOME CLOUDS
AND SNOW SHOWERS/FLURRIES FRIDAY. THEN DRY FOR THE WEEKEND. LOOKS
CHILLY WITH TEMPS BLOW NORMAL.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
331 AM CDT SAT OCT 20 2012
.SHORT TERM...TODAY THROUGH SUNDAY...
LATEST WATER VAPOR IMAGERY SATELLITE IMAGERY SHOWS MID/HIGH LEVEL
CLOUDS STREAMING THROUGH MONTANA INTO NORTH DAKOTA AS A STRONG H3
120KT JET PUNCHES INTO CENTRAL/NORTHERN IDAHO THIS MORNING. AT THE
SURFACE...A WARM FRONT WAS OBSERVED MOVING THROUGH WESTERN AND
CENTRAL NORTH DAKOTA AND THIS WILL CONTINUE TO PROGRESS EAST
DURING THE MORNING. LATEST REGIONAL RADAR SHOWS SOME ENHANCEMENT
TO ECHOES IN EAST CENTRAL MONTANA. THE 00Z GFS WAS FIRST TO LATCH
ONTO THIS...AND NOW WITH DEVELOPMENT UNDERWAY...THE 06Z NAM AND
LATEST RUC SPILL SOME MINOR QPF INTO OUR WESTERN ZONES AROUND 15Z.
HAVE ADDED IN A SLIGHT CHC FOR THE MORNING HOURS. OTHERWISE
WESTERN AND CENTRAL NORTH DAKOTA REMAIN IN THE WARM SECTOR TODAY
WITH HIGHS RANGING BETWEEN 65F AND 75F. WINDS WILL BE STRONGEST
ACROSS THE NORTHWEST INTO NORTH CENTRAL NORTH DAKOTA WHERE THE
NAM/GFS BUFKIT SOUNDINGS SHOW MIXED LAYER WINDS IN THE 20KT TO
25KT RANGE. BEST FORCING/LIFT THIS AFTERNOON REMAINS IN SOUTHERN
CANADA TODAY...HOWEVER CONSENSUS AMONG THE MODELS IS THAT A SLIGHT
CHC FOR A RAINSHOWER IN THE WEST AND NORTH CENTRAL IS POSSIBLE
DURING THE AFTERNOON. HOWEVER THE BETTER CHANCE FOR RAIN SHOWERS
ARRIVES TONIGHT ALONG AND AHEAD OF A COLD FRONT. MUCH COOLER
BEHIND THE COLD FRONT LATE SATURDAY NIGHT INTO SUNDAY WITH HIGHS
COMING BACK TO NORMAL FOR THIS TIME OF YEAR...EXPECT HIGH
TEMPERATURES IN THE LOW TO MID 50S ACROSS WESTERN AND CENTRAL
NORTH DAKOTA. ANY SHOWERS WOULD BE CONFINED TO THE FAR SOUTHWEST.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
PRECIPITATION CHANCES THROUGH MUCH OF THE PERIOD WILL BE THE MAIN
FORECAST CONCERN. THE START OF THE LONG TERM PERIOD WILL FEATURE A
LARGE H5 VORTEX OFF THE COAST OF THE PACIFIC NORTHWEST...WITH
SOUTHWESTERLY FLOW ACROSS THE NORTHERN PLAINS. THE H5 LOW WILL
SEND OCCASIONAL WAVES TOWARDS NORTH DAKOTA ON THE SOUTHWESTERLY
FLOW WHICH WILL BRING OFF AND ON PRECIPITATION CHANCES TO THE
FORECAST AREA.
ONE OF THE HIGHER CHANCES OF PRECIPITATION APPEARS TO COME MONDAY
NIGHT AS A FAIRLY STRONG H7 WAVE MOVES ACROSS THE NORTHERN PLAINS.
MODEL GENERATED VERTICAL MOTION INCREASES IN THE H85-7 LAYER WITH
THE BEST SATURATION IN PARTS OF WESTERN AND NORTHERN NORTH DAKOTA.
WILL CARRY 50 POPS ACROSS THE NORTH...WITH LESSER CHANCES IN THE
20-30 PERCENT RANGE IN THE SOUTHEAST FOR MONDAY NIGHT. FORECAST
SOUNDINGS SUGGEST A RAIN/SNOW MIX IS POSSIBLE MONDAY NIGHT INTO
TUESDAY MORNING ESPECIALLY IN THE NORTHWEST.
THE LARGER SCALE TROUGH ACROSS THE WESTERN CONUS EVENTUALLY MOVES
EAST TOWARDS THE MIDDLE OF NEXT WEEK...THOUGH THE VARIOUS
DETERMINISTIC MODEL RUNS STILL SHOW DIFFERENCES IN HOW THEY HANDLE
ITS PROGRESSION. FOR NOW WILL GO WITH MORE OF A ENSEMBLE/BLENDED
MODEL APPROACH WHICH KEEPS A CHANCE OF PRECIPITATION THROUGH THE
REST OF THE EXTENDED FORECAST PERIOD. WILL GENERALLY CARRY RAIN
DURING THE DAY TIME HOURS...WITH RAIN/SNOW AT NIGHT INTO THE EARLY
MORNINGS.
LOOKING AT TEMPERATURES...A GENERAL COOLING TREND IS EXPECTED
THROUGH THE PERIOD WITH HIGHS MONDAY IN THE MID 40S TO MID
50S...FALLING INTO THE 30S TO LOWER 40S BY FRIDAY.
&&
.AVIATION...THE LOW CLOUDS HAVE EXITED KJMS...HOWEVER A PATCH OF
LOWER CLOUDS STILL EXISTS JUST TO THE WEST OF THE TERMINAL
LOCATION. WILL KEEP AN EYE ON THOSE...AND MAY STILL NEED TO ADD A
PERIOD OF LOWER CLOUDS TO KJMS EARLY THIS MORNING. THE OTHER
TERMINAL LOCATIONS SHOULD REMAIN VFR. THERE WILL BE OCCASIONAL MID
AND HIGH LEVEL CLOUDS...HOWEVER WITH LIMITED LOW LEVEL
MOISTURE...VFR WILL PREVAIL. WINDS BE LIGHT AND FROM THE SOUTH
EARLY THIS MORNING...BUT THEY WILL BECOME MORE WESTERLY WITH TIME
FROM WEST TO EAST AS A WEAK FRONTAL BOUNDARY CROSSES THE AREA.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM/AVIATION...CK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
651 AM EDT SAT OCT 20 2012
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES WILL
CONTINUE TO MOVE NORTHEAST AWAY FROM THE REGION TODAY. HIGH
PRESSURE WILL BUILD IN ITS WAKE TONIGHT INTO SUNDAY. THE HIGH WILL
CONTINUE TO INFLUENCE THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN UPPER LEVEL CLOSED LOW CENTERED OVER SRN MICHIGAN THIS MORNING
WILL CONTINUE TO MOVE NORTHEAST AWAY FROM THE REGION TODAY. IN THE
MEANTIME...AN EMBEDDED VORT LOBE ROTATING AROUND THE LOW WILL
QUICKLY MOVE EAST ACRS THE REGION EARLY THIS MORNING. MOSAIC
RADAR DEPICTED AN AREA OF SHOWERS IN ASSOCIATION WITH THIS
FEATURE... WHICH WAS MOVING INTO THE WHITEWATER AND MIAMI VALLEYS.
AM EXPECTING THESE SHOWERS TO HOLD TOGETHER LONG ENOUGH FOR LIKELY
POPS ACRS THE WHITEWATER AND MIAMI VALLEYS (DAYTON AREA) WITH A
WEAKENING TREND AS IT SHIFTS TOWARD CENTRAL OHIO BY SUNRISE PER
THE HRRR MODEL. OTHERWISE...THE REMAINDER OF THE DAY WILL EXHIBIT
LOW CHANCE POPS DUE TO WEAK DAYTIME INSTABILITY WITH THE THREAT OF
RAIN COMING TO AN END BY THIS EVENING. MOSTLY CLOUDY SKIES WILL
BEGIN TO PARTIALLY CLEAR LATE IN THE DAY. HIGHS TODAY WILL REMAIN
BELOW NORMAL...PEAKING INTO THE LOWER AND MID 50S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD INTO THE OHIO VALLEY
FROM THE SOUTHWEST TONIGHT. SKIES WILL CLEAR...AND WITH WINDS
BECOMING LIGHT...SOME FROST FORMATION IS EXPECTED. PARTS OF THE
AREA REMAIN IN THE FROST/FREEZE PROGRAM AND HAVE ISSUED A FROST
ADVISORY FOR THESE LOCATIONS. LOWS WILL GENERALLY FALL INTO THE
MID AND UPPER 30S...BUT A FEW LOWER 30S CAN NOT BE RULED OUT.
SURFACE HIGH PRESSURE WILL REMAIN OVER THE REGION ON SUNDAY. WITH
AMPLE SUNSHINE AND A MODIFYING AIRMASS...TEMPERATURES WILL WARM
INTO THE LOWER AND MID 60S...WHICH IS ABOUT NORMAL FOR THIS TIME
OF THE YEAR.
FOR THE PERIOD SUNDAY NIGHT INTO MONDAY...CENTER OF THE SURFACE
HIGH WILL MOVE TO A POSITION OVER THE MID ATLANTIC/SE U.S. MODELS
CONTINUE TO INDICATE THAT ALTHOUGH A MID LVL RIDGE WILL BUILD ACRS
THE REGION...IT WILL BE RELATIVELY FLAT IN AMPLITUDE...AND AS
SUCH...WILL ALLOW FOR WEAK FEATURES TO MOVE THROUGH IT. ONE SUCH
FEATURE IS EXPECTED TO BRUSH BY OUR NW MONDAY AFTERNOON INTO
MONDAY EVENING. AT THIS TIME...HAVE INCREASED CLOUDS ACRS THE
REGION...ESPECIALLY NORTHWEST...AND HAVE KEPT THE THREAT FOR
SHOWERS JUST OUTSIDE OUR AREA. THE AIRMASS WILL CONTINUE TO WARM
AND WITH A SOUTHERLY FLOW...TEMPERATURES WILL RISE INTO THE LOWER
AND MID 70S.
FOR MONDAY NIGHT INTO TUESDAY NIGHT...ANOTHER WEAK DISTURBANCE IS
FORECAST TO MOVE THROUGH THE RIDGE. THIS FEATURE WILL COMBINE
WITH SOME ISENTROPIC LIFT TO BRING A THREAT FOR A FEW SHOWERS TO
OUR NWRN ZONES...PARTICULARLY MONDAY NIGHT INTO TUESDAY. OTHER
LOCATIONS WILL GENERALLY SEE PARTLY CLOUDY CONDITIONS.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
MID LEVEL RIDGE WILL REBOUND ON WEDNESDAY AHEAD OF THE NEXT
WEATHER SYSTEM TO AFFECT THE REGION BY THE END OF THE WEEK. ABOVE
NORMAL TEMPERATURES WILL CONTINUE.
A COLD FRONT WILL APPROACH AND MOVE THROUGH THE AREA THURSDAY
NIGHT INTO FRIDAY. AFTER THE FRONT MOVES THROUGH HIGH TEMPERATURES
ON FRIDAY WILL BE IN THE MIDDLE 60S TO AROUND 70.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A LARGE AREA OF LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST AWAY
FROM THE REGION TODAY. BEHIND THE LOW...THERE IS STILL A
CONSIDERABLE AMOUNT OF LOW LEVEL MOISTURE...LEADING TO A DIFFICULT
SET OF TAFS FOR THE FIRST 6-12 HOURS.
RAIN SHOWERS WILL CONTINUE MOVING THROUGH CENTRAL OHIO THIS
MORNING...IMPACTING THE COLUMBUS TAF SITES. MEANWHILE...MOISTURE
HAS BECOME THICKER NEAR THE SURFACE OVER INDIANA OVER THE PAST FEW
HOURS. THIS HAS LED WIDESPREAD CEILINGS THAT ARE STRADDLING THE
MVFR/IFR THRESHOLD...AND SOME IFR CONDITIONS ARE EXPECTED FOR THE
NORTHERN TAF SITES THIS MORNING. THIS FORECAST WILL SLOW DOWN THE
IMPROVEMENT OVER THE COURSE OF THE DAY...WITH NEW MODEL DATA
INDICATING THAT MOSITURE WILL BE SLOW TO SCOUR OUT.
A FEW LIGHT SHOWERS ARE POSSIBLE IN CENTRAL OHIO (KCMH/KLCK)
DURING THE PEAK HEATING HOURS OF THE AFTERNOON...BUT CONFIDENCE IN
TIMING AND PLACEMENT IS LOW.
FOG POTENTIAL ON SUNDAY MORNING IS ALSO A SIGNIFICANT FORECAST
QUESTION. IF CLOUDS ARE ABLE TO CLEAR OUT...CONDITIONS WILL
CERTAINLY SUPPORT FOG DEVELOPMENT.
.OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM 2 AM TO 9 AM EDT SUNDAY FOR OHZ046-055-061-
062-064-070-071-077>079.
KY...FROST ADVISORY FROM 2 AM TO 9 AM EDT SUNDAY FOR KYZ089>099.
IN...FROST ADVISORY FROM 2 AM TO 9 AM EDT SUNDAY FOR INZ073>075-080.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
359 AM EDT SAT OCT 20 2012
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES WILL
CONTINUE TO MOVE NORTHEAST AWAY FROM THE REGION TODAY. HIGH
PRESSURE WILL BUILD IN ITS WAKE TONIGHT INTO SUNDAY. THE HIGH WILL
CONTINUE TO INFLUENCE THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN UPPER LEVEL CLOSED LOW CENTERED OVER SRN MICHIGAN THIS MORNING
WILL CONTINUE TO MOVE NORTHEAST AWAY FROM THE REGION TODAY. IN THE
MEANTIME...AN EMBEDDED VORT LOBE ROTATING AROUND THE LOW WILL
QUICKLY MOVE EAST ACRS THE REGION EARLY THIS MORNING. MOSAIC
RADAR DEPICTED AN AREA OF SHOWERS IN ASSOCIATION WITH THIS
FEATURE... WHICH WAS MOVING INTO THE WHITEWATER AND MIAMI VALLEYS.
AM EXPECTING THESE SHOWERS TO HOLD TOGETHER LONG ENOUGH FOR LIKELY
POPS ACRS THE WHITEWATER AND MIAMI VALLEYS (DAYTON AREA) WITH A
WEAKENING TREND AS IT SHIFTS TOWARD CENTRAL OHIO BY SUNRISE PER
THE HRRR MODEL. OTHERWISE...THE REMAINDER OF THE DAY WILL EXHIBIT
LOW CHANCE POPS DUE TO WEAK DAYTIME INSTABILITY WITH THE THREAT OF
RAIN COMING TO AN END BY THIS EVENING. MOSTLY CLOUDY SKIES WILL
BEGIN TO PARTIALLY CLEAR LATE IN THE DAY. HIGHS TODAY WILL REMAIN
BELOW NORMAL...PEAKING INTO THE LOWER AND MID 50S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD INTO THE OHIO VALLEY
FROM THE SOUTHWEST TONIGHT. SKIES WILL CLEAR...AND WITH WINDS
BECOMING LIGHT...SOME FROST FORMATION IS EXPECTED. PARTS OF THE
AREA REMAIN IN THE FROST/FREEZE PROGRAM AND HAVE ISSUED A FROST
ADVISORY FOR THESE LOCATIONS. LOWS WILL GENERALLY FALL INTO THE
MID AND UPPER 30S...BUT A FEW LOWER 30S CAN NOT BE RULED OUT.
SURFACE HIGH PRESSURE WILL REMAIN OVER THE REGION ON SUNDAY. WITH
AMPLE SUNSHINE AND A MODIFYING AIRMASS...TEMPERATURES WILL WARM
INTO THE LOWER AND MID 60S...WHICH IS ABOUT NORMAL FOR THIS TIME
OF THE YEAR.
FOR THE PERIOD SUNDAY NIGHT INTO MONDAY...CENTER OF THE SURFACE
HIGH WILL MOVE TO A POSITION OVER THE MID ATLANTIC/SE U.S. MODELS
CONTINUE TO INDICATE THAT ALTHOUGH A MID LVL RIDGE WILL BUILD ACRS
THE REGION...IT WILL BE RELATIVELY FLAT IN AMPLITUDE...AND AS
SUCH...WILL ALLOW FOR WEAK FEATURES TO MOVE THROUGH IT. ONE SUCH
FEATURE IS EXPECTED TO BRUSH BY OUR NW MONDAY AFTERNOON INTO
MONDAY EVENING. AT THIS TIME...HAVE INCREASED CLOUDS ACRS THE
REGION...ESPECIALLY NORTHWEST...AND HAVE KEPT THE THREAT FOR
SHOWERS JUST OUTSIDE OUR AREA. THE AIRMASS WILL CONTINUE TO WARM
AND WITH A SOUTHERLY FLOW...TEMPERATURES WILL RISE INTO THE LOWER
AND MID 70S.
FOR MONDAY NIGHT INTO TUESDAY NIGHT...ANOTHER WEAK DISTURBANCE IS
FORECAST TO MOVE THROUGH THE RIDGE. THIS FEATURE WILL COMBINE
WITH SOME ISENTROPIC LIFT TO BRING A THREAT FOR A FEW SHOWERS TO
OUR NWRN ZONES...PARTICULARLY MONDAY NIGHT INTO TUESDAY. OTHER
LOCATIONS WILL GENERALLY SEE PARTLY CLOUDY CONDITIONS.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
MID LEVEL RIDGE WILL REBOUND ON WEDNESDAY AHEAD OF THE NEXT
WEATHER SYSTEM TO AFFECT THE REGION BY THE END OF THE WEEK. ABOVE
NORMAL TEMPERATURES WILL CONTINUE.
A COLD FRONT WILL APPROACH AND MOVE THROUGH THE AREA THURSDAY
NIGHT INTO FRIDAY. AFTER THE FRONT MOVES THROUGH HIGH TEMPERATURES
ON FRIDAY WILL BE IN THE MIDDLE 60S TO AROUND 70.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
SCATTERED RAIN SHOWERS WILL CONTINUE MOVING THROUGH THE REGION
TONIGHT. THE CURRENT BATCH OF SHOWERS WILL EXIT THE AREAS NEAR THE
TAF SITES BY 08Z-10Z...BUT ADDITIONAL RAIN DEVELOPING OVER INDIANA
WILL ALSO BE MOVING IN CLOSER TO DAYBREAK. WHILE PREVAILING VFR
VISIBILITIES ARE EXPECTED IN THE MEAN TIME (WITH MVFR
CEILINGS)...THE SHOWERS WILL BE CAPABLE OF PRODUCING MVFR
VISIBILITIES.
AS THE MOISTURE OVER INDIANA WORKS ITS WAY IN...CONDITIONS WILL
DETERIORATE A BIT FURTHER NEAR DAYBREAK (12Z). CEILINGS WILL
STRADDLE THE MVFR/IFR THRESHOLD...AND MVFR VISIBILITIES WILL
BECOME MORE COMMON. HOWEVER...AFTER 12Z...PRECIPITATION WILL
BECOME LESS LIKELY. CLOUDS MAY BE SLOW TO RISE IN THE
MORNING...BUT VFR CONDITIONS ARE EXPECTED BY AFTERNOON.
A FEW LIGHT SHOWERS ARE POSSIBLE IN CENTRAL OHIO (KCMH/KLCK)
DURING THE PEAK HEATING HOURS OF THE AFTERNOON...BUT CONFIDENCE IN
TIMING AND PLACEMENT IS LOW.
.OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM 2 AM TO 9 AM EDT SUNDAY FOR OHZ046-055-061-
062-064-070-071-077>079.
KY...FROST ADVISORY FROM 2 AM TO 9 AM EDT SUNDAY FOR KYZ089>099.
IN...FROST ADVISORY FROM 2 AM TO 9 AM EDT SUNDAY FOR INZ073>075-080.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/NOVAK
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1157 PM CDT FRI OCT 19 2012
.UPDATE...FOR AVIATION.
&&
.AVIATION...
06Z TAFS...BKN-OVC VFR CIGS ARE EXPECTED THROUGH THE NIGHT WITH
LIGHT WSW WINDS. W WINDS NEAR 8KT EXPECTED SATURDAY...WITH BKN
VFR CIGS GRADUALLY BECMG SCT.
13
&&
.PREV DISCUSSION... /ISSUED 1119 PM CDT FRI OCT 19 2012/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO DEPICT CONTINUED
CLOUDINESS ACROSS NRN PORTIONS OF THE MID STATE WITH BREAKS IN
CLOUD COVERAGE MOST LIKELY ACROSS SRN PORTIONS OF THE MID STATE.
WITH OVERALL CLOUD COVERAGE IN MIND AND CURRENT TEMPS...HAVE ALSO
RAISED LOWS BY A COUPLE OF DEGREES ACROSS THE VAST MAJORITY OF THE
MID STATE...EXPECT LOCATIONS NEAR THE TN/AL BORDER WHERE BREAKS IN
CLOUD COVERAGE MOST LIKELY...THUS ALLOWING FOR COOLER TEMPS. ALSO
MADE AN ADJUSTMENT TO PATCHY FOG FOR SAT NIGHT INTO SUN MORNING...
MENTIONING PATCHY FOG FORMATION MAINLY AFTER MIDNIGHT NEAR BODIES
OF WATER AND THE ELEVATED VALLEYS OF THE PLATEAU AND EXTENDING
THIS THRU THE MID MORNING HRS ON SUN.
PREV DISCUSSION.../ISSUED 601 PM CDT FRI OCT 19 2012/
UPDATE...
CURRENT SFC OBS AND CONSENSUS SHORT RANGE MODEL GUIDANCE...INCLUDING THE
LATEST HIGH RESOLUTION RAPID REFRESH...SHOWING CLDY SKIES ACROSS THE MID
STATE CONTINUING THRU AT LEAST THE MID EVENING HRS...WITH SOME DECREASE
IN CLOUDINESS POSSIBLE LATE EVENING AND OVERNIGHT. HRRR MOST AGGRESSIVE IN
ERODING CLOUD COVERAGE AS COMPARED TO SREF AND RUC 13KM. ACCORDINGLY...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CLDY SKIES THRU
THE EVENING HRS...WITH PTCLDY SKIES OVERNIGHT. ALSO MADE SOME MINOR CHANGES
TO CLOUD COVERAGE ON SAT FOR A TRANSITION TO PTSUNNY SKIES ACROSS THE ENTIRE
MID STATE DURING THIS TIME PERIOD.
31
PREV DISCUSSION.../ISSUED 149 PM CDT FRI OCT 19 2012/
SHORT TERM...LOW LEVEL WRAP-AROUND CLOUDS CONTINUED TO SINK
SOUTHWARD ACROSS THE MID STATE EARLY THIS AFTERNOON. TEMPERATURES
ACROSS THE EXTREME NORTH, WHERE SKIES HAVE BEEN OVC MUCH OF THE
DAY, STALLED OUT IN THE UPPER 50S TO AROUND 60, WHILE SUNNY
SOUTHERN AREAS SAW TEMPS PUSH TO AROUND 70 BY 1 PM. THE LIGHT
RAIN AND SPRINKLES HAVE, SO FAR, REMAINED MOSTLY NORTH OF THE
BORDER (UP ACROSS KY).
BELIEVE LOW LEVEL MOISTURE WILL CONTINUE TO ROTATE AROUND BASE OF
GREAT LAKES AND OHIO VALLEY TROUGH THROUGH SATURDAY, PROVIDING
VARIABLE CLOUDINESS ACROSS OUR NORTHERN COUNTIES. THIS WILL
PRODUCE A TEMP GRADIENT MUCH LIKE TODAY`S, WITH HIGHS TOMORROW
RANGING FROM THE UPPER 50S AND LOWER 60S NORTH AND PLATEAU, TO
AROUND 70 OVER THE SOUTH.
CLOUDS FINALLY DISSIPATE BY SATURDAY NIGHT AND AN UPPER LEVEL
RIDGE BUILDS IN ACROSS THE TENNESSEE VALLEY FOR SUNDAY AND MONDAY.
A WEAKENING SHORTWAVE IS FORECAST TO MOVE OUT OF THE MID-
MISSISSIPPI VALLEY ACROSS THE OHIO RIVER VALLEY ON TUESDAY.
HOWEVER, MAINLY JUST HIGH CLOUDS ARE EXPECTED TO SWEEP ACROSS THE
MID STATE AND KEEP OUR DRY WEATHER IN PLACE.
RIDGE BUILDS BACK IN AFTER WEAK SHORTWAVE PASSES TO OUR NORTHWEST
ON TUESDAY AND, ASIDE FROM SOME HIGH CLOUDS STREAMING IN ON
SOUTHWEST FLOW, DRY WEATHER PERSISTS AT LEAST INTO THE MIDDLE OF
NEXT WEEK.
LONG TERM...LATEST GFS SWEEPS A COLD FRONT ACROSS OUR AREA LATE
NEXT WEEK, ALONG WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS.
HOWEVER, PREVIOUS ECMWF KEPT TENNESSEE VALLEY MORE UNDER THE
INFLUENCE OF HIGH PRESSURE AND DRY WEATHER INTO LATE NEXT WEEK.
UNLESS NEW ECMWF COMES IN WITH A MORE SOLID TREND TOWARD THE GFS,
WILL PROBABLY KEEP A DRY FORECAST RUNNING THROUGH THE EXTENDED PERIOD.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1119 PM CDT FRI OCT 19 2012
.UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO DEPICT CONTINUED
CLOUDINESS ACROSS NRN PORTIONS OF THE MID STATE WITH BREAKS IN
CLOUD COVERAGE MOST LIKELY ACROSS SRN PORTIONS OF THE MID STATE.
WITH OVERALL CLOUD COVERAGE IN MIND AND CURRENT TEMPS...HAVE ALSO
RAISED LOWS BY A COUPLE OF DEGREES ACROSS THE VAST MAJORITY OF THE
MID STATE...EXPECT LOCATIONS NEAR THE TN/AL BORDER WHERE BREAKS IN
CLOUD COVERAGE MOST LIKELY...THUS ALLOWING FOR COOLER TEMPS. ALSO
MADE AN ADJUSTMENT TO PATCHY FOG FOR SAT NIGHT INTO SUN MORNING...
MENTIONING PATCHY FOG FORMATION MAINLY AFTER MIDNIGHT NEAR BODIES
OF WATER AND THE ELEVATED VALLEYS OF THE PLATEAU AND EXTENDING
THIS THRU THE MID MORNING HRS ON SUN.
&&
.PREV DISCUSSION.../ISSUED 640 PM CDT FRI OCT 19 2012/
UPDATE...FOR AVIATION.
AVIATION...
BKN-OVC VFR CIGS ARE EXPECTED THROUGH THE NIGHT WITH DIMINISHING
WSW WINDS. W WINDS WILL PICK UP NEAR 10KT SATURDAY...WITH BKN VFR
CIGS GRADUALLY BECMG SCT.
13
PREV DISCUSSION.../ISSUED 601 PM CDT FRI OCT 19 2012/
UPDATE...
CURRENT SFC OBS AND CONSENSUS SHORT RANGE MODEL GUIDANCE...INCLUDING THE
LATEST HIGH RESOLUTION RAPID REFRESH...SHOWING CLDY SKIES ACROSS THE MID
STATE CONTINUING THRU AT LEAST THE MID EVENING HRS...WITH SOME DECREASE
IN CLOUDINESS POSSIBLE LATE EVENING AND OVERNIGHT. HRRR MOST AGGRESSIVE IN
ERODING CLOUD COVERAGE AS COMPARED TO SREF AND RUC 13KM. ACCORDINGLY...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CLDY SKIES THRU
THE EVENING HRS...WITH PTCLDY SKIES OVERNIGHT. ALSO MADE SOME MINOR CHANGES
TO CLOUD COVERAGE ON SAT FOR A TRANSITION TO PTSUNNY SKIES ACROSS THE ENTIRE
MID STATE DURING THIS TIME PERIOD.
31
PREV DISCUSSION.../ISSUED 149 PM CDT FRI OCT 19 2012/
SHORT TERM...LOW LEVEL WRAP-AROUND CLOUDS CONTINUED TO SINK
SOUTHWARD ACROSS THE MID STATE EARLY THIS AFTERNOON. TEMPERATURES
ACROSS THE EXTREME NORTH, WHERE SKIES HAVE BEEN OVC MUCH OF THE
DAY, STALLED OUT IN THE UPPER 50S TO AROUND 60, WHILE SUNNY
SOUTHERN AREAS SAW TEMPS PUSH TO AROUND 70 BY 1 PM. THE LIGHT
RAIN AND SPRINKLES HAVE, SO FAR, REMAINED MOSTLY NORTH OF THE
BORDER (UP ACROSS KY).
BELIEVE LOW LEVEL MOISTURE WILL CONTINUE TO ROTATE AROUND BASE OF
GREAT LAKES AND OHIO VALLEY TROUGH THROUGH SATURDAY, PROVIDING
VARIABLE CLOUDINESS ACROSS OUR NORTHERN COUNTIES. THIS WILL
PRODUCE A TEMP GRADIENT MUCH LIKE TODAY`S, WITH HIGHS TOMORROW
RANGING FROM THE UPPER 50S AND LOWER 60S NORTH AND PLATEAU, TO
AROUND 70 OVER THE SOUTH.
CLOUDS FINALLY DISSIPATE BY SATURDAY NIGHT AND AN UPPER LEVEL
RIDGE BUILDS IN ACROSS THE TENNESSEE VALLEY FOR SUNDAY AND MONDAY.
A WEAKENING SHORTWAVE IS FORECAST TO MOVE OUT OF THE MID-
MISSISSIPPI VALLEY ACROSS THE OHIO RIVER VALLEY ON TUESDAY.
HOWEVER, MAINLY JUST HIGH CLOUDS ARE EXPECTED TO SWEEP ACROSS THE
MID STATE AND KEEP OUR DRY WEATHER IN PLACE.
RIDGE BUILDS BACK IN AFTER WEAK SHORTWAVE PASSES TO OUR NORTHWEST
ON TUESDAY AND, ASIDE FROM SOME HIGH CLOUDS STREAMING IN ON
SOUTHWEST FLOW, DRY WEATHER PERSISTS AT LEAST INTO THE MIDDLE OF
NEXT WEEK.
LONG TERM...LATEST GFS SWEEPS A COLD FRONT ACROSS OUR AREA LATE
NEXT WEEK, ALONG WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS.
HOWEVER, PREVIOUS ECMWF KEPT TENNESSEE VALLEY MORE UNDER THE
INFLUENCE OF HIGH PRESSURE AND DRY WEATHER INTO LATE NEXT WEEK.
UNLESS NEW ECMWF COMES IN WITH A MORE SOLID TREND TOWARD THE GFS,
WILL PROBABLY KEEP A DRY FORECAST RUNNING THROUGH THE EXTENDED PERIOD.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
1102 PM CDT SUN OCT 21 2012
.UPDATE...
AS OF 11 PM...SATELLITE IMAGERY SHOWS THE SHORT WAVE TROUGH LIFTING
NORTHEAST INTO SOUTHERN NEW MEXICO AND SOUTHWEST TEXAS...WITH
SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE TRANS PECOS REGION.
LATEST NAM AND HRRR GUIDANCE HAS BACKED OFF ON RAIN CHANCES ACROSS
WESTERN AND NORTHWEST SECTIONS OVERNIGHT...KEEPING PRECIPITATION
WELL WEST OF THE AREA THROUGH 12Z. THIS SEEMS REASONABLE AS THE
MAJORITY OF THE LIFT ASSOCIATED WITH THE SHORT WAVE WILL STAY WEST
OF US OVERNIGHT. STILL CANNOT RULE OUT SOME ACTIVITY OVER WESTERN
SECTIONS AFTER MIDNIGHT. FOR THIS UPDATE...POPS WERE REMOVED ACROSS
THE EASTERN BIG COUNTRY FOR THE REST OF THE NIGHT AND SKY GRIDS
WERE ADJUSTED TO REFLECT CURRENT TRENDS. ALSO TWEAKED TEMPERATURES
A BIT...MAINLY ACROSS THE BIG COUNTRY WHERE MIN TEMPERATURES WERE
RAISED A COUPLE OF DEGREES. UPDATED PRODUCTS HAVE BEEN SENT.
&&
.PREV DISCUSSION... /ISSUED 556 PM CDT SUN OCT 21 2012/
AVIATION...
/00Z UPDATE/
CEILINGS OVER ALL BUT KABI WILL DEGRADE TO MVFR AFTER
MIDNIGHT...AROUND SUNRISE AT KSJT AND A FEW HOURS EARLIER AT THE
SOUTHERN TERMINALS. KABI SHOULD REMAIN VFR. CEILINGS AT ALL
TERMINALS WILL LIFT TO VFR BY NOON. SOUTHERLY WINDS AT KABI WILL
REMAIN ELEVATED THROUGH THE PERIOD GUSTING TO AROUND 25KT. AT THE
REMAINING TERMINALS WINDS WILL GUST TO NEAR 25 KTS BY NOON...WITH
KSJT WINDS GUSTING TO AROUND 20 KTS AT DAYBREAK AND INCREASING TO
AROUND 25 KTS BY NOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 90 69 82 67 84 / 10 20 30 10 0
SAN ANGELO 90 68 85 67 85 / 10 20 20 10 0
JUNCTION 90 69 87 67 85 / 10 10 10 10 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JW/99
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
334 AM CDT SAT OCT 20 2012
.SHORT TERM...
TEMPS ARE RUNNING 10-15 DEGREES WARMER THAN THEY WERE 24 HOURS AGO
AND THIS TREND WILL CONTINUE THROUGHOUT THE DAY. A STRONG H250 JET
MOVING ACROSS THE PACNW AND NORTHERN ROCKIES WILL PROPAGATE INTO THE
NORTHERN PLAINS LATER TODAY. THE RIGHT EXIT REGION OF THIS JET...IN
CONJUNCTION WITH ENHANCED DPVA CONCOMITANT WITH THE ASSOCIATED
SHORTWAVE TROF...WILL PROMOTE LEE CYCLOGENESIS THROUGHOUT THE SHORT
TERM. THE EFFECT WILL BE GUSTY SOUTH TO SOUTHWEST WINDS TODAY AND A
STRONG LOW LEVEL JET OVERNIGHT. BOTH THE NAM/GFS BUFR SOUNDINGS
INDICATE H800 TEMPS NEAR 19C...WHICH IS ABOUT 5 DEGREES WARMER THAN
WHAT WE SAW YESTERDAY /PER RAP SOUNDINGS/. GIVEN IDENTICAL MIXING
AND INSOLATION...THAT WOULD TRANSLATE TO SURFACE TEMPS BEING 9F
WARMER THAN ON FRIDAY. A SLIGHT INCREASE IN HIGH CLOUD COVER MAY BE
ABLE TO OFFSET THE ENHANCED COMPRESSIONAL HEATING FROM THE SOUTHWEST
WINDS TO KEEP TEMPS FROM WARMING FURTHER. THE RECORD HIGH TODAY FOR
BOTH ABILENE AND SAN ANGELO IS 93 DEGREES. I DO NOT THINK WE WILL
GET THERE BUT SAN ANGELO MAY GET CLOSE.
A SIGNIFICANT INCREASE IN LOW LEVEL MOISTURE TODAY WILL CARRY OVER
INTO THE OVERNIGHT HOURS AND WILL KEEP TEMPS FROM COOLING AS QUICKLY
AS IN PAST DAYS. MOS FORECAST TEMPS FOR ABILENE/SAN ANGELO INDICATE
OVERNIGHT LOWS IN THE VICINITY OF THE RECORD HIGH MINIMUMS /UPPER
60S/. MY GUT SAYS WE WILL COOL JUST BELOW THE MOS VALUES BUT LOWS IN
THE 64-67 DEGREE RANGE SHOULD BE COMMON. WINDS ARE EXPECTED TO GUST
AS WE APPROACH MIDNIGHT ALONG I-20 AND THE CONCHO VALLEY AS THE LOW
LEVEL JET INTENSIFIES. FINALLY...LOW CLOUDS ARE EXPECTED TO DEVELOP
OVER THE HILL COUNTRY AND SPREAD NORTH OVERNIGHT...POTENTIALLY
REACHING AS FAR NORTH AS I-20. NO RAIN IS EXPECTED IN THE NEXT 24
HOURS.
JOHNSON
.LONG TERM...
CUT OFF UPPER LOW OFF THE WEST COAST OF BAJA CALIFORNIA EXPECTED
TO MOVE EAST THIS WEEKEND. NAM...GFS...AND EC MODELS SHOW FAIRLY
GOOD CONSENSUS...BRINGING LIFT AHEAD OF THE LOW AFTER 1 AM
MONDAY...WITH THE BEST LIFT AND SHOWER AND THUNDERSTORM CHANCES
DAYBREAK THROUGH NOON MONDAY. BIG COUNTRY AND NORTHERN CONCHO
VALLEY INDICATED TO HAVE THE BEST POTENTIAL RAIN. COULD SEE A FEW
STRONG ELEVATED STORMS DEVELOP WITH 0-6 KM BULK SHEARS OF 35 KTS
AND MUCAPES OF 1500 TO 2000 J/KG. EARLY MORNING IS NOT AS CONDUCIVE
TO SEVERE WEATHER BUT CAN NOT RULE IT OUT.
GFS AND EC STILL INDICATING COLD FRONTS LATE NEXT WEEK...ONE
MOVING THROUGH THURSDAY...WITH SECOND REINFORCEMENT OF COLDER AIR
SATURDAY. WILL CONTINUE TO TREND TOWARD COLDER TEMPERATURES.
RAINFALL POTENTIAL FOR THURSDAY LOOKS LOW...BUT COULD POTENTIALLY
SEE SOME OVERRUNNING NEXT WEEKEND.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 89 68 90 68 82 / 0 0 10 20 30
SAN ANGELO 91 67 90 67 85 / 0 0 10 20 20
JUNCTION 89 67 89 69 87 / 0 0 10 20 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
604 PM CDT SUN OCT 21 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
309 PM CDT SUN OCT 21 2012
PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS EXPECTED INTO MID
WEEK WITH A WARM AND HUMID AIR MASS THAT WILL MOVE INTO THE REGION
OVERNIGHT.
CURRENTLY...A MID TO UPPER LEVEL RIDGE EXTENDS FROM THE GREAT
LAKES DOWN TO THE GULF COAST WITH BROAD MID LEVEL TROUGHING SLOWLY
PROPAGATING EAST ACROSS THE PACIFIC NORTHWEST AND SOUTHWESTERN
CANADA. A PREVIOUSLY CUT OFF MID LEVEL LOW OVER THE NORTHERN PART
OF BAJA CALIFORNIA HAS BEEN PICKED UP BY THE STRENGTHENING
SOUTHWEST FLOW WITH A SECONDARY MID LEVEL SHORTWAVE NOTED ON WATER
VAPOR AND RAP ANALYSIS ACROSS THE SOUTHERN PLAINS. THE FIRST WEAK
SHORTWAVE IN THE SOUTHERN PLAINS WILL MOVE INTO THE REGION THIS
EVENING AND BRING THE FIRST WAVE OF CLOUD COVER ALONG WITH IT.
LOW LEVEL MOISTURE TRANSPORT WILL RAPIDLY INCREASE OVERNIGHT AS
THE SECOND MID LEVEL SHORT WAVE LIFTS UP INTO THE REGION BETWEEN
6-12Z. ELEVATED INSTABILITY INCREASES AS THIS TRANSPORT KICKS IN
WITH 0-3KM SKINNY MUCAPE OF AROUND 500 J/KG GETTING INTO NORTHEAST
IOWA AND SOUTHWEST WISCONSIN BEFORE DAYBREAK. BASED ON THIS
INCREASING FORCING AND INSTABILITY...FELT CONFIDENT ENOUGH TO RAMP
UP THE PRECIPITATION CHANCES OVERNIGHT ON INTO TOMORROW. THE
SEVERE THREAT DOES NOT LOOK TOO HIGH WITH THE SKINNY CAPE AND
BETTER SHEAR FURTHER NORTH FROM THIS INSTABILITY AXIS THOUGH SOME
SMALL HAIL WILL BE POSSIBLE THOUGH OUT OF SOME OF THIS CONVECTION.
THE COLUMN SATURATES OUT REGION WIDE TOMORROW MORNING WITH THE
MOISTURE TRANSPORT SHIFTING EAST THROUGH THE DAY ALONG WITH THE
SHORTWAVE. AS PREVIOUSLY MENTIONED...CONFIDENCE HAS INCREASED
ENOUGH WITH THE 21.12Z NAM/GFS/GEM/ECMWF AND 21.09Z SREF ALL
SHOWING HIGH PROBABILITIES OF PRECIPITATION DEVELOPING ACROSS
THE AREA IN THE MORNING AND SHIFTING EAST IN THE AFTERNOON.
DESPITE THE LOW LEVEL WARM AIR ADVECTION...HAVE DECIDED TO SHAVE A
FEW DEGREES OFF OF HIGH TEMPERATURES TOMORROW WITH THE AMOUNT OF
CLOUD COVER AND RAIN THAT WILL BE AROUND THROUGH MUCH OF THE DAY.
SOME CLEARING COULD OCCUR IN THE AFTERNOON FROM THE SOUTHWEST AND
WILL PROBABLY BE WHEN WE HIT OUR HIGHS FOR THE DAY. WITH THE
BETTER SHEAR REMAINING OFF TO THE NORTH OF THE
FORCING/MOISTURE...IT DOES NOT APPEAR AS THOUGH THERE WILL BE ANY
WIDESPREAD SEVERE WEATHER THOUGH A FEW STORMS COULD STILL PRODUCE
SOME HAIL DURING THE DAY.
THE WARM FRONT WILL THEN STALL OUT ACROSS THE REGION TOMORROW
NIGHT THROUGH WEDNESDAY BEFORE THE NEXT SYSTEM MOVES ACROSS THE
NORTHERN PLAINS AND LIFTS THE FRONT TO THE NORTH. WITH THIS FRONT
LINGERING...THERE WILL REMAIN A CHANCE FOR SOME SHOWERS/STORMS
THROUGH MID WEEK THOUGH THERE DOES NOT APPEAR TO BE MUCH IN THE
WAY OF A FORCING TRIGGER. HAVE KEPT PRECIPITATION CHANCES ON THE
LOW SIDE GOING INTO MID WEEK AS A RESULT. TEMPERATURES AND
HUMIDITY WILL BE ABOVE NORMAL WITH DEW POINTS LINGERING AROUND 60
ACROSS THE FORECAST AREA AND TEMPERATURES IN THE 70S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
309 PM CDT SUN OCT 21 2012
PATTERN CHANGE COMING LATER THIS WEEK AFTER A COLD FRONT COMES
THROUGH AND THE SOUTHWESTERLY FLOW ALOFT GOES WEST TO NORTHWEST.
A BROAD MID TO UPPER LEVEL TROUGH WILL SLOWLY PROPAGATE ACROSS THE
NORTHERN PLAINS AND INTO THE GREAT LAKES FROM MID WEEK INTO NEXT
WEEKEND WITH AM EMBEDDED MID LEVEL TROUGH THAT DEVELOPS ALONG THE
SOUTHEASTERN PERIPHERY OF IT WEDNESDAY NIGHT INTO THURSDAY. THE
GFS HAS BEEN THE MOST CONSISTENT WITH THIS SYSTEM AND THE COLD
FRONT PASSAGE WITH THE ECMWF AND GEM COMING AROUND TO ITS TREND
OVER THE PAST FEW RUNS. THIS SOLUTION IS A LESS AMPLIFIED TO WHAT
THE 21.12Z ECMWF OFFERS UP WITH A POSITIVELY TILTED MID LEVEL
TROUGH SWINGING THROUGH. THE 21.12Z GFS/GEM BRING THIS COLD FRONT
INTO THE REGION WEDNESDAY NIGHT AND HAVE IT INTO THE WESTERN GREAT
LAKES BY THURSDAY AFTERNOON.
AFTER THE FRONT COMES THROUGH...NORTHWESTERLY FLOW WILL USHER IN
MUCH COLDER AIR IN FROM CANADA WITH 850MB TEMPERATURES DROPPING
DOWN TO AROUND -7C WITH HIGH TEMPERATURES STUCK IN THE 40S BY NEXT
WEEKEND. ANOTHER SYSTEM TRACKS ALONG THE COLD FRONT ON FRIDAY BUT
EACH FORM OF 21.12Z GUIDANCE HAS A DIFFERING SOLUTION WITH HOW FAR
NORTHWEST THE PRECIPITATION MAKES IT. WITH THE GFS BEING THE MOST
CONSISTENT OVER THE PAST FEW DAYS...HAVE OPTED TO GO ALONG WITH IT
AND ITS TIMING. 21.12Z GFS BUFKIT SOUNDINGS SHOW THAT IT COULD BE
COLD ENOUGH TO CHANGE THE PRECIPITATION TYPE OVER TO SNOW
BRIEFLY...SO HAVE INTRODUCED A MIX OF RAIN AND SNOW SHOWERS EARLY
SATURDAY MORNING.
&&
.AVIATION...TONIGHT AND MONDAY
603 PM CDT SUN OCT 21 2012
SHORT WAVE TROUGH OVER EASTERN COLORADO THIS AFTERNOON IS EXPECTED
TO MOVE SLOWLY NORTHEAST TOWARD THE AREA TONIGHT AND THEN ACROSS
THE REGION MONDAY. THE FORCING AHEAD OF THE WAVE WILL BEGIN TO
INCREASE LATE TONIGHT...BUT THE 21.18Z NAM SUGGESTS THE BEST PV
ADVECTION IN THE 500-300 MB LAYER WILL STAY SOUTH OF THE AREA WITH
AROUND 4 PVU/S PASSING THROUGH MONDAY MORNING. THIS IS STILL
EXPECTED TO BE ENOUGH FORCING ALONG WITH AROUND 2-3 UBAR/S OF UP
GLIDE ON THE 300K ISENTROPIC SURFACE TO PRODUCE SOME SHOWERS. THE
TIMING OF THE NAM ALONG WITH THE 21.12Z HI-RES ARW AND NMM SUGGEST
THESE SHOWERS WILL HOLD OFF UNTIL AFTER 12Z MONDAY AND THEN EXIT
TO THE EAST DURING THE MIDDLE OF THE AFTERNOON. AREA OF
STRATOCUMULUS OVER NORTHERN MISSOURI IS SPREADING STEADILY NORTH
AND EXPECT THIS MOISTURE TO ARRIVE AT THE TAF SITES AROUND 06Z
LOWERING BOTH THE VISIBILITY AND CEILINGS TO MVFR. THESE
CONDITIONS SHOULD THEN HOLD UNTIL A COUPLE HOURS AFTER THE RAIN
BEGINS AND THE LOW LEVELS BECOME SATURATED ALLOWING THE CEILINGS
TO COME DOWN TO IFR AND THEN STAY THERE THROUGH THE REMAINDER OF
THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
309 PM CDT SUN OCT 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 PM CDT SUN OCT 21 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
309 PM CDT SUN OCT 21 2012
PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS EXPECTED INTO MID
WEEK WITH A WARM AND HUMID AIR MASS THAT WILL MOVE INTO THE REGION
OVERNIGHT.
CURRENTLY...A MID TO UPPER LEVEL RIDGE EXTENDS FROM THE GREAT
LAKES DOWN TO THE GULF COAST WITH BROAD MID LEVEL TROUGHING SLOWLY
PROPAGATING EAST ACROSS THE PACIFIC NORTHWEST AND SOUTHWESTERN
CANADA. A PREVIOUSLY CUT OFF MID LEVEL LOW OVER THE NORTHERN PART
OF BAJA CALIFORNIA HAS BEEN PICKED UP BY THE STRENGTHENING
SOUTHWEST FLOW WITH A SECONDARY MID LEVEL SHORTWAVE NOTED ON WATER
VAPOR AND RAP ANALYSIS ACROSS THE SOUTHERN PLAINS. THE FIRST WEAK
SHORTWAVE IN THE SOUTHERN PLAINS WILL MOVE INTO THE REGION THIS
EVENING AND BRING THE FIRST WAVE OF CLOUD COVER ALONG WITH IT.
LOW LEVEL MOISTURE TRANSPORT WILL RAPIDLY INCREASE OVERNIGHT AS
THE SECOND MID LEVEL SHORT WAVE LIFTS UP INTO THE REGION BETWEEN
6-12Z. ELEVATED INSTABILITY INCREASES AS THIS TRANSPORT KICKS IN
WITH 0-3KM SKINNY MUCAPE OF AROUND 500 J/KG GETTING INTO NORTHEAST
IOWA AND SOUTHWEST WISCONSIN BEFORE DAYBREAK. BASED ON THIS
INCREASING FORCING AND INSTABILITY...FELT CONFIDENT ENOUGH TO RAMP
UP THE PRECIPITATION CHANCES OVERNIGHT ON INTO TOMORROW. THE
SEVERE THREAT DOES NOT LOOK TOO HIGH WITH THE SKINNY CAPE AND
BETTER SHEAR FURTHER NORTH FROM THIS INSTABILITY AXIS THOUGH SOME
SMALL HAIL WILL BE POSSIBLE THOUGH OUT OF SOME OF THIS CONVECTION.
THE COLUMN SATURATES OUT REGION WIDE TOMORROW MORNING WITH THE
MOISTURE TRANSPORT SHIFTING EAST THROUGH THE DAY ALONG WITH THE
SHORTWAVE. AS PREVIOUSLY MENTIONED...CONFIDENCE HAS INCREASED
ENOUGH WITH THE 21.12Z NAM/GFS/GEM/ECMWF AND 21.09Z SREF ALL
SHOWING HIGH PROBABILITIES OF PRECIPITATION DEVELOPING ACROSS
THE AREA IN THE MORNING AND SHIFTING EAST IN THE AFTERNOON.
DESPITE THE LOW LEVEL WARM AIR ADVECTION...HAVE DECIDED TO SHAVE A
FEW DEGREES OFF OF HIGH TEMPERATURES TOMORROW WITH THE AMOUNT OF
CLOUD COVER AND RAIN THAT WILL BE AROUND THROUGH MUCH OF THE DAY.
SOME CLEARING COULD OCCUR IN THE AFTERNOON FROM THE SOUTHWEST AND
WILL PROBABLY BE WHEN WE HIT OUR HIGHS FOR THE DAY. WITH THE
BETTER SHEAR REMAINING OFF TO THE NORTH OF THE
FORCING/MOISTURE...IT DOES NOT APPEAR AS THOUGH THERE WILL BE ANY
WIDESPREAD SEVERE WEATHER THOUGH A FEW STORMS COULD STILL PRODUCE
SOME HAIL DURING THE DAY.
THE WARM FRONT WILL THEN STALL OUT ACROSS THE REGION TOMORROW
NIGHT THROUGH WEDNESDAY BEFORE THE NEXT SYSTEM MOVES ACROSS THE
NORTHERN PLAINS AND LIFTS THE FRONT TO THE NORTH. WITH THIS FRONT
LINGERING...THERE WILL REMAIN A CHANCE FOR SOME SHOWERS/STORMS
THROUGH MID WEEK THOUGH THERE DOES NOT APPEAR TO BE MUCH IN THE
WAY OF A FORCING TRIGGER. HAVE KEPT PRECIPITATION CHANCES ON THE
LOW SIDE GOING INTO MID WEEK AS A RESULT. TEMPERATURES AND
HUMIDITY WILL BE ABOVE NORMAL WITH DEW POINTS LINGERING AROUND 60
ACROSS THE FORECAST AREA AND TEMPERATURES IN THE 70S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
309 PM CDT SUN OCT 21 2012
PATTERN CHANGE COMING LATER THIS WEEK AFTER A COLD FRONT COMES
THROUGH AND THE SOUTHWESTERLY FLOW ALOFT GOES WEST TO NORTHWEST.
A BROAD MID TO UPPER LEVEL TROUGH WILL SLOWLY PROPAGATE ACROSS THE
NORTHERN PLAINS AND INTO THE GREAT LAKES FROM MID WEEK INTO NEXT
WEEKEND WITH AM EMBEDDED MID LEVEL TROUGH THAT DEVELOPS ALONG THE
SOUTHEASTERN PERIPHERY OF IT WEDNESDAY NIGHT INTO THURSDAY. THE
GFS HAS BEEN THE MOST CONSISTENT WITH THIS SYSTEM AND THE COLD
FRONT PASSAGE WITH THE ECMWF AND GEM COMING AROUND TO ITS TREND
OVER THE PAST FEW RUNS. THIS SOLUTION IS A LESS AMPLIFIED TO WHAT
THE 21.12Z ECMWF OFFERS UP WITH A POSITIVELY TILTED MID LEVEL
TROUGH SWINGING THROUGH. THE 21.12Z GFS/GEM BRING THIS COLD FRONT
INTO THE REGION WEDNESDAY NIGHT AND HAVE IT INTO THE WESTERN GREAT
LAKES BY THURSDAY AFTERNOON.
AFTER THE FRONT COMES THROUGH...NORTHWESTERLY FLOW WILL USHER IN
MUCH COLDER AIR IN FROM CANADA WITH 850MB TEMPERATURES DROPPING
DOWN TO AROUND -7C WITH HIGH TEMPERATURES STUCK IN THE 40S BY NEXT
WEEKEND. ANOTHER SYSTEM TRACKS ALONG THE COLD FRONT ON FRIDAY BUT
EACH FORM OF 21.12Z GUIDANCE HAS A DIFFERING SOLUTION WITH HOW FAR
NORTHWEST THE PRECIPITATION MAKES IT. WITH THE GFS BEING THE MOST
CONSISTENT OVER THE PAST FEW DAYS...HAVE OPTED TO GO ALONG WITH IT
AND ITS TIMING. 21.12Z GFS BUFKIT SOUNDINGS SHOW THAT IT COULD BE
COLD ENOUGH TO CHANGE THE PRECIPITATION TYPE OVER TO SNOW
BRIEFLY...SO HAVE INTRODUCED A MIX OF RAIN AND SNOW SHOWERS EARLY
SATURDAY MORNING.
&&
.AVIATION...THROUGH 18Z MONDAY
1137 AM CDT SUN OCT 21 2012
A SURGE OF MOISTURE AHEAD OF LOW PRESSURE OVER THE PLAINS WILL PUSH
STRATUS INTO THE AREA THIS EVENING. QUESTION REMAINS HOW LOW CLOUD
BASES WILL BE WHEN THE STRATUS ROLLS IN. MODEL SOUNDING CONSENSUS
SHOWS MAINLY MVFR SOMEWHERE IN THE 2-3KFT RANGE. STRATUS AND
VISIBILITY WILL LIKELY LOWER INTO IFR/POSSIBLY LIFR RANGE AROUND
8-10Z WITH LOWER BOUNDARY LAYER BECOMING VERY SATURATED. FURTHER
LIFT AND SATURATION ALONG WITH WEAK INSTABILITY ALOFT WILL ALSO
BRING SCATTERED SHRA/ISOLD T INTO THE AREA IN THE SAME TIME FRAME.
THESE CONDITIONS ARE THEN EXPECTED TO LAST THROUGH THE DAY MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
309 PM CDT SUN OCT 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
319 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 18Z SUNDAY
1236 PM CDT SAT OCT 20 2012
STRATUS/FOG WILL CONTINUE TO BE THE MAIN CONCERN THROUGH THE TAF
PERIOD. SKIES HAVE FINALLY CLEARED AT KLSE WITH MOSTLY IFR STRATUS
HOLDING FIRM ACROSS THE HIGHER TERRAIN OF SOUTHEAST MN/NORTHEAST
IA...INCLUDING KRST TAF SITE. THIS LOW LEVEL MOISTURE IS TRAPPED
UNDER A RIDGE OF HIGH PRESSURE EXTENDING PRETTY MUCH N/S ALONG THE
MISSISSIPPI RIVER VALLEY. RIDGE AXIS TO SHIFT SLOWLY EASTWARD
TONIGHT WITH WINDS OUT THE SOUTH AROUND 5KT OR SO AT THE
KLSE/KRST TAF SITES. WITH COOLING OF THE RELATIVELY MOIST LOWER
BOUNDARY LAYER...EXPECTING IFR/LIFR STRATUS FILL IN AGAIN AFTER
SUNSET. MODEL SOUNDINGS HAVE WINDS JUST OFF THE SURFACE AT
600-900FT AGL EXPECTED IN THE 15-20KT RANGE FROM THE SOUTH-
SOUTHWEST OVERNIGHT. THIS SHOULD PREVENT DENSE FOG FORMATION AT
THE SURFACE BUT MAINTAINING IFR/LIFR STRATUS. EXPECTING LOW CLOUDS
TO SCATTER FINALLY AROUND 14Z SUNDAY AS BETTER BOUNDARY LAYER
MIXING OCCURS IN SOUTHERLY FLOW. THROUGH THE REST OF
SUNDAY...AFTER THE STRATUS SCATTERS...PLAN ON SCATTERED MID/HIGH
CLOUDS WITH BASES AOA 12KFT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
319 PM CDT SAT OCT 20 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1034 PM PDT SUN OCT 21 2012
...RAINY AND BREEZY WEATHER LATE TONIGHT AND MONDAY MORNING...
.DISCUSSION...AS OF 9:00 PM PDT SUNDAY...MAJOR CHANGE IN OUR
WEATHER PATTERN IS UNDERWAY AND CONTINUE TO EXPECT RAIN TO SPREAD
OVER MUCH OF OUR DISTRICT LATE TONIGHT AND MONDAY. LATEST IR SAT
IMAGERY IS CONSISTENT WITH NEW 00Z NAM MODEL OUTPUT IN DEPICTING A
FRONTAL WAVE IN ITS EARLY STAGE OF DEVELOPMENT A FEW HUNDRED KM
OFFSHORE FROM SAN FRANCISCO AND MOVING RAPIDLY TO THE EAST. THE
ASSOCIATED UPPER LEVEL FLOW HAS ALSO ENTRAINED A SUBTROPICAL
MOISTURE PLUME WHICH IS NOW APPROACHING THE CENTRAL CALIFORNIA
COAST. RECENTLY RECEIVED 03Z NESDIS ANALYSIS HAS LATEST SATELLITE
MICROWAVE DERIVED MAX 6-HR RAIN ACCUMULATIONS THROUGH 23Z OF
0.25-0.5" CENTERED AROUND 35N/132W TO 38N/130W. NESDIS ANALYSIS ALSO
NOTES GOES SAT RAIN ESTIMATES SHOWING A SLIGHT INCREASING TREND TO
OFFSHORE RAIN RATES CONSISTENT WITH INCREASING ORGANIZATION
APPARENT IN BAROCLINIC LEAF CLOUD AND COOLING OF CLOUD TOPS.
LATEST KMUX BASE REFLECTIVITY IS INDICATING SCATTERED RETURNS IN
THE 30 TO 35 DBZ RANGE NOW TO WITHIN ABOUT 30 MILES OF OUR COAST
(ALBEIT ABOVE 10K FT DUE TO 0.5 DEG TILT OF BASE SCAN).
BOTH 00Z NAM AND 00Z 3-KM HRRR INDICATE ONSET OF PRECIP IN OUR CWA
WILL OCCUR AROUND MIDNIGHT IN THE GENERAL VICINITY OF THE SANTA
CRUZ MTNS...IN ASSOCIATION WITH THE AFOREMENTIONED MOISTURE PLUME.
THEN DURING THE OVERNIGHT HOURS...THIS BAND OF LIGHT RAIN IS
PROJECTED TO RAPIDLY SPREAD OVER THE SOUTHERN SF BAY AREA AND
MONTEREY BAY REGION...WHILE AT THE SAME TIME THE PRIMARY FRONTAL
RAIN BAND BEGINS MOVING IN TO THE NORTHERN SONOMA COUNTY COAST. LATEST
MODEL OUTPUT INDICATES IT WILL SPREAD MODERATE RAIN...AND LOCALLY
GUSTY SOUTHERLY WINDS...INTO THE CENTRAL SF BAY AREA AROUND THE
TIME OF THE MONDAY MORNING COMMUTE. IT DOES LOOK LIKE IT WILL MOVE
THROUGH PRETTY QUICKLY THOUGH...SO PERIOD OF MORE SIGNIFICANT
RAIN RATES SHOULD BE PRETTY SHORT. AND NEW GUIDANCE INDICATES
SOMEWHAT LOWER SHOWER CHANCES THEN PREVIOUS THINKING DURING THE
DAY FOLLOWING PASSAGE...AS WELL AS ONLY PARTLY CLOUDY SKIES.
RAINFALL TOTALS THROUGH MIDDAY MONDAY SHOULD RANGE FROM UP TO ABOUT 1
AND 1/4 INCHES IN THE WETTEST PORTIONS OF THE NORTH BAY COASTAL
HILLS...TO AROUND THE 1/4 TO 1/2 INCH RANGE LOWER ELEVATIONS
AROUND SF BAY. ANOTHER ROUND OF SHOWERS CONTINUES TO APPEAR ON
TAP FOR MONDAY NIGHT HOWEVER.
WILL MAKE SOME UPDATES TO THE FORECAST CONSISTENT WITH THE ABOVE.
AM ALSO GOING TO UPDATE THE HAZARDOUS WEATHER OUTLOOK (SEE
SFOHWOMTR...FLUS46 KMTR) TO HIGHLIGHT POTENTIAL RISK TO MOTORISTS
OF THIS FIRST SIGNIFICANT RAIN OF SEASON FOR MUCH OF THE BAY
AREA...AS LONG-ACCUMULATED OILS IN THE PAVEMENT ARE LEACHED OUT
AND ENHANCE SLIPPERINESS OF ROADWAYS.
FROM PREVIOUS DISCUSSION...RAIN CHANCES WILL CONTINUE AT LEAST THROUGH
WEDNESDAY AS PIECES OF ENERGY ROTATE AROUND THE LONGWAVE TROF THAT
WILL BECOME ELONGATED. NONE OF THESE LOOK NEARLY AS STRONG AS
WHEAT WE ARE EXPECTING FOR TOMORROW...HOWEVER RAINFALL TOTALS FOR
MULTIPLE EVENTS WILL START TO ADD UP. ANOTHER INCH LOCALLY WOULD
NOT BE OUT OF THE QUESTION FOR TUESDAY THROUGH THURSDAY. IT IS
ALSO WORTH NOTING THAT BEHIND THE FRONT INSTABILITY WILL INCREASE
AS COLD AIR ADVECTION TAKES PLACE. DECIDED TO ADD A SLIGHT CHANCE
FOR THUNDER ON TUESDAY OVER THE NORTH BAY WHERE THE DYNAMICS ARE
THE MOST FAVORABLE.
DRIER WEATHER RETURNS BY NEXT WEEKENDS AS THE STORM TRACK MOVES
BACK MORE TO THE NORTH. HIGHS WILL RETURN TO THE 60S AND 70S.
&&
.AVIATION...AS OF 10:30 PM SUNDAY...CLOUDS INCREASING TONIGHT
AHEAD OF THE FRONTAL SYSTEM. REMAINING VFR TONIGHT BUT CIGS
LOWERING INTO MVFR RANGE BY 14Z AS MAIN PART OF THE FRONT ARRIVES.
RADAR PICKING UP RETURNS JUST OFFSHORE SO LOOK FOR RAIN TO BEGIN BY
AROUND MIDNIGHT. SOUTHERLY WINDS INCREASING LATE TONIGHT REACHING
THEIR MAXIMUM SPEEDS MONDAY MORNING. WIND SHIFT WITH FRONTAL
PASSAGE EXPECTED AROUND NOON IN THE SFO BAY AREA AND 21Z IN THE
MRY BAY AREA WITH WINDS SWITCHING TO WEST. RAIN TURNS TO SHOWERS
AFTER FRONTAL PASSAGE.
VICINITY OF KSFO...CONDITIONS WILL REMAIN VFR THROUGH TONIGHT AS
CIGS WILL STAY ABOVE 3000 FEET. MVFR CIGS AFTER 14Z WITH CIGS NEAR
OR JUST BELOW 3000 FEET. RAIN BEGINNING AFTER AROUND 08Z TURNING
TO SHOWERS AFTER 18Z. WINDS WILL TURN MORE SOUTHERLY LATE TONIGHT
WITH SOUTH TO SOUTHEAST WINDS GUSTING UP TO 25 KT MONDAY MORNING.
WIND SHIFT TO WEST EXPECTED 18-20Z WITH GUSTS UP TO 30 KT IN THE
AFTERNOON BECOMING VFR. WIND DECREASING BY MONDAY EVENING.
KSFO BRIDGE APPROACH...SAME AS KSFO.
MONTEREY BAY AREA TERMINALS...CONDITIONS WILL REMAIN VFR THROUGH
TONIGHT AS CIGS WILL STAY ABOVE 3000 FEET. SOUTHERLY WINDS
INCREASING TO 10 TO 20 KT MONDAY MORNING WITH STRONGEST WINDS IN
THE SNS VALLEY. RAIN BEGINNING AFTER 09-10Z ENDING AFTER FRONTAL
PASSAGE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 11 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 2 AM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 2 AM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 5 AM
&&
$$
PUBLIC FORECAST: BLIER/BELL
AVIATION/MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
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WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
934 PM PDT SUN OCT 21 2012
.SHORT TERM DISCUSSION...
UPPER LOW IS CENTERED JUST OFF THE BRITISH COLUMBIA COAST WITH
ASSOCIATED LARGE TROUGH EXTENDING SOUTH ALONG THE WEST COAST.
PLENTY OF COLD AIR ACCOMPANIES THIS TROUGH AS NOTED BY SPECKLED
NATURE TO CLOUDS ROTATING SOUTH TOWARDS THE NORTHWEST COAST AND
HAVE EVEN SEEN A FEW LIGHTNING STRIKES WEST OF EUREKA. TROUGH
WILL DEEPEN SOUTHWARD OVER THE WESTERN STATES TONIGHT AND MONDAY
PRODUCING SIGNIFICANT HEIGHT FALLS AND MUCH COOLER TEMPERATURES
OVER NORCAL. THE FIRST SIGNIFICANT PRECIPITATION EVENT OF THE
SEASON IS SET TO BEGIN LATER TONIGHT AS MOISTURE WITH STRONG JET
STREAM ENERGY MOVES OVER THE AREA.
RADAR IS SHOWING PRECIP INCREASING IN COVERAGE JUST WEST OF THE
BAY AREA AT 930 PM. HRRR BRINGS THIS PRECIP INTO THE SACRAMENTO
AREA BETWEEN 11 PM AND 12 AM AND THIS LOOKS LIKE PRETTY GOOD
TIMING GIVEN TRENDS. CURRENT POP GRIDS ALSO HANDLE THIS WELL WITH
LIKELY OR HIGHER POPS AREA-WIDE AFTER 11 PM. HEAVIER BAND OF
PRECIP IS CURRENTLY FROM CRESCENT CITY TO EUREKA AND WILL DROP
SOUTHEAST INTO THE NRN SAC VALLEY OVERNIGHT AND CENT/SRN SAC
VALLEY MONDAY MORNING. TEMPERATURES ARE SLIGHTLY COOLER THIS
EVENING WITH 9 PM READINGS FROM THE LOW 50`S DELTA TO LOW 60`S
NRN SAC VALLEY. THESE VALUES ARE 2 TO 5 DEGS COOLER VERSUS
YESTERDAY AT THIS TIME. FORECASTED VALLEY LOWS FROM THE MID 40`S
TO LOW 50`S LOOK ON TRACK AND NO EVENING UPDATE WILL BE MADE.
PREVIOUS DISCUSSION...
WE/RE ON THE VERGE OF A SIGNIFICANT CHANGE TOWARD COOLER AND MORE
UNSETTLED WEATHER ACROSS INTERIOR NORCAL. A COLD EARLY SEASON
TROUGH OVER THE EPAC WILL SEND SEVERAL WEATHER SYSTEMS THROUGH THE
REGION INTO MID-WEEK BRINGING RAIN TO THE VALLEY AND SNOW TO THE
MOUNTAINS ALONG WITH MUCH COOLER TEMPERATURES.
MID AND HIGH CLOUDS ASSOCIATED WITH THE UPPER-LEVEL FRONT AND
INITIAL BATCH OF UPPER JET ENERGY HAS BEEN SLOWLY MOVING SOUTHWARD
THROUGH THE FORECAST AREA TODAY. MUCH OF THE SACRAMENTO VALLEY IS
CLEARING OUT BY MID-AFTERNOON AND IT LOOKS LIKE WE COULD STILL
MAKE A RUN FOR SOME 70 DEGREE MAX TEMPS TODAY. THE NORTHERN SAN
JOAQUIN VALLEY AND MUCH OF THE NORTHERN SIERRA REMAIN OVERCAST.
KDAX RADAR IS STARTING TO PICK UP SOME LIGHT ELEVATED RETURNS
SOUTH OF I-80...MOST LIKELY VIRGA...BUT WOULD NOT BE TOO SURPRISED
TO SEE SOME REPORTS OF SPRINKLES OR LIGHT SHOWERS THROUGH THE LATE
AFTERNOON AS THESE CLOUDS MOVE SOUTH OUT OF THE AREA.
SATIMG SHOWS A DOUBLE LEAF STRUCTURE BEGINNING TO DEVELOP OFF THE
COAST. MODELS CONTINUE TO SHOW RAPID DEVELOPMENT OF THIS SYSTEM
OFFSHORE THIS EVENING...SO EXPECT SATIMG TO SHOW QUITE A BIT OF
ENHANCEMENT DURING THE NEXT 6 TO 8 HOURS. PRECIP IS STILL EXPECTED
TO SPREAD INLAND LATER TONIGHT AS WARM ADVECTION INCREASES. THE
HEAVIEST PRECIP IS EXPECTED THROUGH MIDDAY MONDAY AS THE COLD
FRONT MOVES THROUGH FOLLOWED BY SCATTERED SHOWERS AND A FEW
THUNDERSTORMS. UPSLOPE FLOW AND STEEPER MID-LEVEL LAPSE RATE WILL
CONTINUE SIGNIFICANT PRECIP IN THE NORTHERN SIERRA INTO AT LEAST
TUESDAY MORNING.
ANOTHER SYSTEMS IS FORECAST TO BRING MORE SHOWERS TO THE REGION
TUESDAY INTO WEDNESDAY.
&&
.EXTENDED DISCUSSION (THURSDAY THROUGH SUNDAY)
SHOWERS DECREASE THURSDAY AS UPPER LOW PROGRESSES INTO THE
INTER-MOUNTAIN WEST. MODELS DIFFER ON AMOUNT OF UPSTREAM RIDGING OVER
THE AREA FRIDAY INTO THE WEEKEND. OPER GFS HAS TRENDED A MORE FLAT
RIDGE WHILE THE ECMWF-HIRES AND GEM FAVOR A HIGHER AMPLITUDE WAVE.
CURRENT FORECAST IS A COMPILATION OF THE SOLUTIONS WITH A SLIGHT
CHANCE OF WEEKEND SHOWERS ADVERTISED OVER NORTHERN MOUNTAINS WHILE
THE REMAINDER OF THE CWA HAS DRIER AND WARMER WEATHER THROUGH SUNDAY.
&&
.AVIATION...
OFFSHR UPR TROF AND ASSOCD CDFNT MOV INTO INTR NORCAL OVNGT INTO
MON. DTRTG CONDS AFT MIDNGT WITH AREAS OF MVFR IN THE CNTRL VLY AFT
10Z. OMTNS AREAS MVFR/IFR CONDS OVNGT BCMG WSPRD MON MRNG. SN LVLS
LWRG TO ARND 045 OVR SHASTA MTNS BY MON MRNG AND 050-060 OVR CSTL
MTNS AND SIERNEV MON. INCRSG WLY FLOW ALF WITH SLY SFC WND TO 25KTS
IN CNTRL VLY AFT 10Z AND LCL S-SW 35G50KT OVR HYR MTN TRRN MON.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 AM PDT TUESDAY ABOVE 5500 FEET FOR
THE WEST SLOPE NORTHERN SIERRA NEVADA...WESTERN PLUMAS
COUNTY/LASSEN PARK.
WINTER WEATHER ADVISORY UNTIL 5 PM PDT MONDAY ABOVE 5000 FEET
FOR THE MOUNTAINS SOUTHWESTERN SHASTA COUNTY TO NORTHERN LAKE
COUNTY.
WINTER WEATHER ADVISORY UNTIL 5 PM PDT MONDAY ABOVE 3500 FEET
FOR THE BURNEY BASIN / EASTERN SHASTA COUNTY...SHASTA LAKE AREA
/ NORTHERN SHASTA COUNTY.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
918 PM PDT SUN OCT 21 2012
.SYNOPSIS...
A PACIFIC STORM SYSTEM IS CURRENTLY APPROACHING CENTRAL CALIFORNIA
AND WILL MOVE OVER THE AREA TONIGHT...BRINGING A CHANCE OF RAIN AND
HIGHER ELEVATION SNOW. THIS SYSTEM WILL CONTINUE IMPACTING THE AREA
THROUGH AT LEAST TUESDAY...TEMPERATURES ARE EXPECTED TO BE COOLER
FOR THE REMAINDER OF THIS WEEK AS ONSHORE FLOW CONTINUES.
&&
.DISCUSSION...SATELLITE AND RADAR SHOW THE LEADING FRONTAL BAND
HAS DISSIPATED OVER THE YOSEMITE AREA. MEANWHILE WATER VAPOR
IMAGERY SHOWS AN IMPRESSIVE BAROCLINIC LEAF TO THE NORTHWEST OF
THE BAY AREA. THIS INDICATES INCREASING LIFT AND DYNAMICS WHICH
WILL HELP TO DEVELOP A SECONDARY MORE POTENT FRONTAL SYSTEM WHICH
MODELS DRIVE SOUTHEAST INTO THE CENTRAL CALIFORNIA INTERIOR ON
MONDAY. BOTH RUC AND LATEST NAM12 MODELS GENERATE MOST QPF OVER
THE SIERRA WITH AMOUNTS OF UP TO AROUND 0.15" NEAR MERCED AND NEAR
ZERO DOWN TO FRESNO. QUITE A DIFFERENT STORY IN THE SIERRA WHERE
SAME MODELS GENERATE UP TO 1.50" AT YOSEMITE. CURRENT FORECAST HAS
THESE AREAS TARGETED AND WILL NOT NEED TO UPDATE THIS EVENING.
MEANWHILE WINDS OVER THE ANTELOPE VALLEY SECTION OF THE KERN
COUNTY DESERT DIED OFF EARLIER THIS EVENING PROMPTING THE
CANCELLATION OF THE WIND ADVISORY FOR TONIGHT. WINDS SHOULD PICK
UP AGAIN ON MONDAY OVER THESE SAME AREAS. &&
.AVIATION...
AREAS MVFR CIGS DEVELOPING AND SPREADING SOUTH OVER THE SOUTHERN
SIERRA WITH SCATTERED SHOWERS...LOWERING CIGS AND AREAS MOUNTAIN
OBSCURATION THROUGH 06Z TUESDAY. ISOLATED MVFR IN SHOWERS ACROSS THE
SAN JOAQUIN VALLEY AFTER 12Z MONDAY. VFR CONDITIONS CAN BE EXPECTED
ACROSS THE KERN COUNTY DESERT THROUGH 06Z TUESDAY.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS LOW.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS LOW.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO MIDNIGHT PDT
MONDAY NIGHT ABOVE 6000 FEET FOR THE CAZ096.
WIND ADVISORY FROM 11 AM TO 8 PM PDT MONDAY CAZ098-099.
&&
$$
PUBLIC...DUDLEY
AVN/FW...DCH
SYNOPSIS...WP
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
911 PM PDT SUN OCT 21 2012
...RAINY AND BREEZY WEATHER LATE TONIGHT AND MONDAY MORNING...
.DISCUSSION...AS OF 9:00 PM PDT SUNDAY...MAJOR CHANGE IN OUR
WEATHER PATTERN IS UNDERWAY AND CONTINUE TO EXPECT RAIN TO SPREAD
OVER MUCH OF OUR DISTRICT LATE TONIGHT AND MONDAY. LATEST IR SAT
IMAGERY IS CONSISTENT WITH NEW 00Z NAM MODEL OUTPUT IN DEPICTING A
FRONTAL WAVE IN ITS EARLY STAGE OF DEVELOPMENT A FEW HUNDRED KM
OFFSHORE FROM SAN FRANCISCO AND MOVING RAPIDLY TO THE EAST. THE
ASSOCIATED UPPER LEVEL FLOW HAS ALSO ENTRAINED A SUBTROPICAL
MOISTURE PLUME WHICH IS NOW APPROACHING THE CENTRAL CALIFORNIA
COAST. RECENTLY RECEIVED 03Z NESDIS ANALYSIS HAS LATEST SATELLITE
MICROWAVE DERIVED MAX 6-HR RAIN ACCUMULATIONS THROUGH 23Z OF
0.25-0.5" CENTERED AROUND 35N/132W TO 38N/130W. NESDIS ANALYSIS ALSO
NOTES GOES SAT RAIN ESTIMATES SHOWING A SLIGHT INCREASING TREND TO
OFFSHORE RAIN RATES CONSISTENT WITH INCREASING ORGANIZATION
APPARENT IN BAROCLINIC LEAF CLOUD AND COOLING OF CLOUD TOPS.
LATEST KMUX BASE REFLECTIVITY IS INDICATING SCATTERED RETURNS IN
THE 30 TO 35 DBZ RANGE NOW TO WITHIN ABOUT 30 MILES OF OUR COAST
(ALBEIT ABOVE 10K FT DUE TO 0.5 DEG TILT OF BASE SCAN).
BOTH 00Z NAM AND 00Z 3-KM HRRR INDICATE ONSET OF PRECIP IN OUR CWA
WILL OCCUR AROUND MIDNIGHT IN THE GENERAL VICINITY OF THE SANTA
CRUZ MTNS...IN ASSOCIATION WITH THE AFOREMENTIONED MOISTURE PLUME.
THEN DURING THE OVERNIGHT HOURS...THIS BAND OF LIGHT RAIN IS
PROJECTED TO RAPIDLY SPREAD OVER THE SOUTHERN SF BAY AREA AND
MONTEREY BAY REGION...WHILE AT THE SAME TIME THE PRIMARY FRONTAL
RAIN BAND BEGINS MOVING IN TO THE NORTHERN SONOMA COUNTY COAST. LATEST
MODEL OUTPUT INDICATES IT WILL SPREAD MODERATE RAIN...AND LOCALLY
GUSTY SOUTHERLY WINDS...INTO THE CENTRAL SF BAY AREA AROUND THE
TIME OF THE MONDAY MORNING COMMUTE. IT DOES LOOK LIKE IT WILL MOVE
THROUGH PRETTY QUICKLY THOUGH...SO PERIOD OF MORE SIGNIFICANT
RAIN RATES SHOULD BE PRETTY SHORT. AND NEW GUIDANCE INDICATES
SOMEWHAT LOWER SHOWER CHANCES THEN PREVIOUS THINKING DURING THE
DAY FOLLOWING PASSAGE...AS WELL AS ONLY PARTLY CLOUDY SKIES.
RAINFALL TOTALS THROUGH MIDDAY MONDAY SHOULD RANGE FROM UP TO ABOUT 1
AND 1/4 INCHES IN THE WETTEST PORTIONS OF THE NORTH BAY COASTAL
HILLS...TO AROUND THE 1/4 TO 1/2 INCH RANGE LOWER ELEVATIONS
AROUND SF BAY. ANOTHER ROUND OF SHOWERS CONTINUES TO APPEAR ON
TAP FOR MONDAY NIGHT HOWEVER.
WILL MAKE SOME UPDATES TO THE FORECAST CONSISTENT WITH THE ABOVE.
AM ALSO GOING TO UPDATE THE HAZARDOUS WEATHER OUTLOOK (SEE
SFOHWOMTR...FLUS46 KMTR) TO HIGHLIGHT POTENTIAL RISK TO MOTORISTS
OF THIS FIRST SIGNIFICANT RAIN OF SEASON FOR MUCH OF THE BAY
AREA...AS LONG-ACCUMULATED OILS IN THE PAVEMENT ARE LEACHED OUT
AND ENHANCE SLIPPERINESS OF ROADWAYS.
FROM PREVIOUS DISCUSSION...RAIN CHANCES WILL CONTINUE AT LEAST THROUGH
WEDNESDAY AS PIECES OF ENERGY ROTATE AROUND THE LONGWAVE TROF THAT
WILL BECOME ELONGATED. NONE OF THESE LOOK NEARLY AS STRONG AS
WHEAT WE ARE EXPECTING FOR TOMORROW...HOWEVER RAINFALL TOTALS FOR
MULTIPLE EVENTS WILL START TO ADD UP. ANOTHER INCH LOCALLY WOULD
NOT BE OUT OF THE QUESTION FOR TUESDAY THROUGH THURSDAY. IT IS
ALSO WORTH NOTING THAT BEHIND THE FRONT INSTABILITY WILL INCREASE
AS COLD AIR ADVECTION TAKES PLACE. DECIDED TO ADD A SLIGHT CHANCE
FOR THUNDER ON TUESDAY OVER THE NORTH BAY WHERE THE DYNAMICS ARE
THE MOST FAVORABLE.
DRIER WEATHER RETURNS BY NEXT WEEKENDS AS THE STORM TRACK MOVES
BACK MORE TO THE NORTH. HIGHS WILL RETURN TO THE 60S AND 70S.
&&
.AVIATION...AS OF 4:30 PM SUNDAY...MID AND HIGH CLOUDS WILL
INCREASE EARLY TONIGHT AHEAD OF A FRONTAL SYSTEM. RAIN SPREADING
SOUTH AFTER 08Z BUT CIGS WILL STAY IN THE VFR RANGE. SOUTHERLY
WINDS INCREASE LATE TONIGHT REACHING THEIR MAXIMUM SPEEDS MONDAY
MORNING. WIND SHIFT WITH FRONTAL PASSAGE EXPECTED AROUND NOON IN
THE SFO BAY AREA AND 21Z IN THE MRY BAY AREA WITH WINDS SWITCHING
TO WEST. RAIN TURNS TO SHOWERS AFTER FRONTAL PASSAGE.
VICINITY OF KSFO...CONDITIONS WILL REMAIN VFR THROUGH MONDAY AS
CIGS WILL STAY ABOVE 3000 FEET. RAIN BEGINNING AFTER AROUND 08Z
TURNING TO SHOWERS AFTER 18Z. WINDS WILL TURN MORE SOUTHERLY LATE
TONIGHT WITH SOUTH WINDS TO 16 KT MONDAY MORNING. WIND SHIFT TO
WEST EXPECTED 18-20Z BECOMING GUSTY UP TO 30 KT IN THE AFTERNOON.
KSFO BRIDGE APPROACH...SAME AS KSFO.
MONTEREY BAY AREA TERMINALS...CONDITIONS WILL REMAIN VFR THROUGH
MONDAY AS CIGS WILL STAY ABOVE 3000 FEET. LIGHT SOUTHERLY WINDS
DEVELOPING AFTER 04Z INCREASING TO 10 KT MIDMORNING MONDAY. RAIN
BEGINNING AFTER AROUND 12Z ENDING AFTER FRONTAL PASSAGE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 11 PM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM FROM 2 AM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 2 AM
SCA...PT REYES TO PIGEON PT 0-10 NM FROM 5 AM
&&
$$
PUBLIC FORECAST: BLIER/BELL
AVIATION/MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS TAUNTON MA
409 AM EDT MON OCT 22 2012
.SYNOPSIS...
DRY AND SEASONABLE WEATHER IS EXPECTED TO CONTINUE THROUGH TUESDAY
AFTERNOON. A WEAK WARM FRONT COULD BRING A PERIOD OF LIGHT RAIN
FROM LATE TUE INTO WED NIGHT. THEREAFTER CANADIAN HIGH PRESSURE
DELIVERS DRY AND SEASONABLE WEATHER THU AND FRI. A BRIEF WARM UP
MAY OCCUR SAT BEFORE WET AND WINDY WEATHER POSSIBLY MOVES UP THE
EASTERN SEABOARD SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WV IMG COMBINED WITH CURRENT RAP DATA SUGGESTS SHEARED VORT MAX IS
JUST NOW MAKING ITS WAY INTO NW PORTIONS OF THE FA THIS MORNING.
THE COMBINATION OF THIS WAVE AN H85 LLJ OF ABOUT 40 KT AND STRONG
CAA FROM AN EXITING CUTOFF HAVE GENERATED A FAIR AMOUNT OF SC
OVERNIGHT...AND KEPT A 5-12KT WIND. GIVEN THIS FACT...MODELS
STRUGGLE WITH TEMPS/DWPTS AND ARE GENERALLY TOO LOW ACROSS THE
BOARD. HAVE ADJUSTED TEMPS/DWPTS CLOSER TO THE HIGHER BC GRIDS FOR
THE REMAINING OVERNIGHT TEMPS AND THE HIGHS TODAY. THIS LED TO
ANOTHER DAY OF TEMPS IN THE LOWER 60S ACROSS THE AREA...WHICH IS
GENERALLY SEASONABLE FOR THIS TIME OF YEAR.
OTHERWISE...THE WEAK VORT MAX WILL ALLOW FOR A WEAK SFC WAVE TO
TIGHTEN THE SFC PRES GRADIENT IN ADVANCE OF THE HIGH PRES BUILDING
OVER FROM THE SW. WHILE THE LLJ IS 40+ KT IN THE EARLY MORNING
HOURS THIS MORNING...THE COMBINATION OF LACKING DIURNAL MIXING AND
A FAIRLY ROBUST SUBSIDENCE INVERSION WILL KEEP BL FROM TAPPING
THIS LEVEL. HOWEVER...SHOULD STILL SEE A BIT STRONGER W TO NW
GUSTS TODAY THAN YESTERDAY WITH SOME 30 MPH POSSIBLE. THESE
BLUSTERY CONDITIONS WILL MAKE THINGS SEEM A BIT COOLER THAN
NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
HIGH PRES BEGINS TO CREST OVER THE REGION AS WEAK H5 RIDGE MOVES
IN BEHIND THE EXITING VORT MAX. THIS SHOULD ALLOW SKIES TO CLEAR
AND WINDS TO DECOUPLE OVERNIGHT. THEREFORE...DRY CONDITIONS
PREVAIL AND MIN TEMPS COOLER THAN SUN NIGHT. UPPER 30S NW WITH
LOWER 40S TOWARD THE SE.
TUE...
EXPECTING CLOUDS TO GRADUALLY INCREASE FROM THE SW AS A SLOWING
WARM FRONT APPROACHES. NOT EXPECTING THE FRONT ITSELF TO MAKE IT
INTO SRN NEW ENGLAND AS IT ENCOUNTERS BLOCKING FLOW PATTERN TO THE
NE AND BECOMES PARALLEL WITH MID AND UPPER LVL FLOW.
HOWEVER...GUIDANCE SOUNDINGS SUPPORT SOME MOISTURE LOADING OF THE
COLUMN AND GIVEN SOME WEAK OVERRUNNING FLOW AND F-GEN...MAY SEE
THE DEVELOPMENT OF SCATTERED SHOWERS BY LATE DAY...PARTICULARLY TO
THE W AND S. NOT EXPECTING A WASHOUT...AS SOUNDINGS TAKE SOME TIME
TO MOISTEN AND FORCING IS RELATIVELY WEAK. HIGHS WILL BE SIMILAR
TO PREVIOUS DAYS GIVEN LITTLE CHANGE IN AIRMASS AND LOW LVL COOL
AIR SHOULD KEEP WARM FRONT AT BAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* LIGHT RAIN POSSIBLE TUE NIGHT THRU WED NGT...OTHERWISE DRY WX
* SEASONABLE TEMPERATURES MUCH OF THE WORK WEEK
* RAIN AND WIND POSSIBLE LATE NEXT WEEKEND INTO EARLY NXT WK
TUE NIGHT THROUGH FRI...
00Z MODELS IN VERY GOOD AGREEMENT ON LONG WAVE TROUGH PERSISTING
OVER NEWFOUNDLAND MUCH OF THIS WEEK. THIS PRECLUDES WARM AIRMASS
OVER THE GREAT LAKES AND MID ATLC REGION FROM ADVECTING NORTHEAST
INTO NEW ENGLAND. THE WARM AIR DOES MAKES A RUN AT NEW ENGLAND TUE
NIGHT INTO WED NIGHT AS SURFACE WAVE RIDES THE BOUNDARY INTO THE
REGION. THUS A PERIOD OF LIGHT RAIN IS POSSIBLE DURING THIS TIME.
DESPITE LIKELY POPS FROM THE GMOS...WE PREFERRED TO CAP POPS AT HIGH
CHANCE GIVEN QPF APPEARS LIGHT AND THERE MAY BE SUFFICIENT DRY AIR
OVER THE AREA TO ERODE SOME OF THE PRECIP. WED WILL LIKELY BE THE
COOLEST DAY OF THE WEEK...ESP IF RAIN MATERIALIZES.
GIVEN THE DEVELOPING BLOCK PATTERN THE WARM FRONT REMAINS SOUTH OF
THE AREA WITH CANADIAN HIGH PRES SETTLING OVER NEW ENGLAND THU INTO
FRI. THUS SHALLOW COOL AIR SHOULD WIN OUT OVER THE AREA MUCH OF THE
WEEK. HOWEVER THIS STILL YIELDS TEMPERATURES NEAR NORMAL WITH HIGHS
IN THE 60S. IN FACT IT WILL FEEL QUITE PLEASANT FOR LATE OCT WITH AT
LEAST PARTIAL SUNSHINE AND LIGHT WINDS.
SAT/SUN...
A PIECE OF THE WARM AIRMASS OVER THE GREAT LAKES AND OH VLY MAY
ADVECT INTO THE REGION FRI OR SAT AS MID LEVEL RIDGE BRIEFLY SLIDES
ACROSS NEW ENGLAND. THIS SHOULD CONTINUE DRY WEATHER FROM FRI INTO
SAT. THEREAFTER THE DRAMA BUILDS AS TELECONNECTIONS/ENSEMBLES AND
DETERMINISTIC MODEL RUNS ALL SUPPORT A PATTERN/FLOW REGIME CHANGE AS
THE NAO AND AO BECOMING INCREASINGLY NEGATIVE LATE NEXT WEEKEND INTO
EARLY NEXT WEEK. TO INCREASE THE COMPLEXITY OF THE PATTERN CHANGE
IS THE LIKELIHOOD /TPC EST 80% CHC OF DVLPMNT/ OF A TROPICAL CYCLONE
/TS SANDY/ EMERGING FROM THE CARIBBEAN TO THE NEAR THE SOUTHEAST
STATES OF THE U.S. THE ECMWF/ECENS AND TO A LESSER EXTENT THE UKMET
HAVE A PHASED SOLUTION...WITH THE AMPLIFIED POLAR JET CAPTURING THE
TROPICAL CYCLONE OFF THE SOUTHEAST COAST FORMING A HYBRID SYSTEM
INTO THE MID ATLC AND NORTHEAST SUN/MON.
THE NEW GFS OFFERS AN UNPHASED SOLUTION...HAVING THE POLAR JET
KICKING THE TROPICAL CYCLONE OUT TO SEA WITHOUT MUCH FANFARE FOR THE
NORTHEAST. AT THIS TIME RANGE WE MUST EXPECT THE DETERMINISTIC
MODELS TO WAVER BACK AND FORTH BETWEEN PHASED AND UNPHASED SOLUTIONS
FOR THE REMAINDER OF THE UPCOMING WEEK. THE INTERACTION BETWEEN THE
POLAR JET /ITS AMPLITUDE AND TILT/ AND POTENTIAL TROPICAL CYCLONE IS
VERY COMPLEX AND OFFERS LOW PREDICTABILITY AT THIS TIME RANGE. THUS
MODELS WILL UNLIKELY RESOLVE THESE COMPLEX INTERACTIONS UNTIL
SOMETIME FRI OR SAT. SO WILL MAINTAIN CHANCE POPS SUN TO ADDRESS
THIS UNCERTAINTY AND INCLUDE SOME WORDING IN THE HWO TO HIGHLIGHT A
LOW RISK OF SIGNIFICANT PRECIP AND STRONG WINDS WITH HYBRID LOW
ALONG OR NEAR THE EAST COAST.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...HIGH CONFIDENCE.
VFR. W TO NW WINDS WITH GUSTS 20-30 KT FROM MID MORNING THROUGH
THE AFTERNOON. WINDS DIMINISH DURING THE EVENING.
KBOS TAF...HIGH CONFIDENCE IN TAF.
VFR. W TO NW WINDS GUST 20-30 KT MID MORNING INTO THE
AFTERNOON...WEAKENING IN THE EVENING.
KBDL TAF...HIGH CONFIDENCE IN TAF.
VFR. W TO NW WINDS GUST 20-30 KT MID MORNING INTO THE
AFTERNOON...WEAKENING IN THE EVENING.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE TO HIGH CONFIDENCE FOR A PERIOD OF MVFR IN LIGHT RAIN TUE
NGT THRU WED NGT. LOW RISK OF IFR DURING THIS TIME. IMPROVING
CONDITIONS THU AND FRI...LIKELY TO VFR BUT CAN/T RULE OUT MVFR CIGS
AT TIMES.
&&
.MARINE...
HIGH CONFIDENCE.
W TO NW WINDS TODAY WITH GUSTS OF 20-30 KT OVER ALL WATERS.
THEREFORE...SMALL CRAFT ADVISORIES STAND INTO THE EVENING FOR NEAR
SHORE WATERS...AND INTO THE OVERNIGHT FOR OUTER WATERS AS SEAS OF
5-6 FT MAY TAKE SOME TIME TO DIMINISH ON THE OUTER WATERS.
HIGH PRES BUILDS OVER THE WATERS LATE TONIGHT INTO TUE...WHICH
WILL ALLOW WINDS/SEAS TO SUBSIDE AND QUIET BOATING WX TO RETURN.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE TO HIGH CONFIDENCE FOR QUIET WEATHER WITH HIGH PRES OVER
THE NORTHEAST. A WARM FRONT APPROACHES NEW ENGLAND TUE NGT THRU WED
NGT YIELDING PERIODS OF LIGHT RAIN AND REDUCED VSBY. HOWEVER WARM
FRONT SLIDES SOUTH OF NEW ENGLAND THU AND FRI WITH HIGH PRES
REINSERTING ITSELF OVER THE NORTHEAST. THUS NO SIGNIFICANT WIND OR
SEAS THIS PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ231>234.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 7 PM EDT THIS
EVENING FOR ANZ230-235>237-251.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ254>256.
&&
$$
SYNOPSIS...NOCERA/DOODY
NEAR TERM...DOODY
SHORT TERM...DOODY
LONG TERM...NOCERA
AVIATION...NOCERA/DOODY
MARINE...NOCERA/DOODY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
355 AM EDT MON OCT 22 2012
.SYNOPSIS...
DRY AND SEASONABLE WEATHER IS EXPECTED TO CONTINUE THROUGH
TUESDAY AFTERNOON. A WEAK WARM FRONT COULD BRING A FEW SHOWERS
TUESDAY NIGHT INTO WEDNESDAY. UNSEASONABLY MILD WEATHER MAY
BRIEFLY RETURN BY LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WV IMG COMBINED WITH CURRENT RAP DATA SUGGESTS SHEARED VORT MAX IS
JUST NOW MAKING ITS WAY INTO NW PORTIONS OF THE FA THIS MORNING.
THE COMBINATION OF THIS WAVE AN H85 LLJ OF ABOUT 40 KT AND STRONG
CAA FROM AN EXITING CUTOFF HAVE GENERATED A FAIR AMOUNT OF SC
OVERNIGHT...AND KEPT A 5-12KT WIND. GIVEN THIS FACT...MODELS
STRUGGLE WITH TEMPS/DWPTS AND ARE GENERALLY TOO LOW ACROSS THE
BOARD. HAVE ADJUSTED TEMPS/DWPTS CLOSER TO THE HIGHER BC GRIDS FOR
THE REMAINING OVERNIGHT TEMPS AND THE HIGHS TODAY. THIS LED TO
ANOTHER DAY OF TEMPS IN THE LOWER 60S ACROSS THE AREA...WHICH IS
GENERALLY SEASONABLE FOR THIS TIME OF YEAR.
OTHERWISE...THE WEAK VORT MAX WILL ALLOW FOR A WEAK SFC WAVE TO
TIGHTEN THE SFC PRES GRADIENT IN ADVANCE OF THE HIGH PRES BUILDING
OVER FROM THE SW. WHILE THE LLJ IS 40+ KT IN THE EARLY MORNING
HOURS THIS MORNING...THE COMBINATION OF LACKING DIURNAL MIXING AND
A FAIRLY ROBUST SUBSIDENCE INVERSION WILL KEEP BL FROM TAPPING
THIS LEVEL. HOWEVER...SHOULD STILL SEE A BIT STRONGER W TO NW
GUSTS TODAY THAN YESTERDAY WITH SOME 30 MPH POSSIBLE. THESE
BLUSTERY CONDITIONS WILL MAKE THINGS SEEM A BIT COOLER THAN
NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
HIGH PRES BEGINS TO CREST OVER THE REGION AS WEAK H5 RIDGE MOVES
IN BEHIND THE EXITING VORT MAX. THIS SHOULD ALLOW SKIES TO CLEAR
AND WINDS TO DECOUPLE OVERNIGHT. THEREFORE...DRY CONDITIONS
PREVAIL AND MIN TEMPS COOLER THAN SUN NIGHT. UPPER 30S NW WITH
LOWER 40S TOWARD THE SE.
TUE...
EXPECTING CLOUDS TO GRADUALLY INCREASE FROM THE SW AS A SLOWING
WARM FRONT APPROACHES. NOT EXPECTING THE FRONT ITSELF TO MAKE IT
INTO SRN NEW ENGLAND AS IT ENCOUNTERS BLOCKING FLOW PATTERN TO THE
NE AND BECOMES PARALLEL WITH MID AND UPPER LVL FLOW.
HOWEVER...GUIDANCE SOUNDINGS SUPPORT SOME MOISTURE LOADING OF THE
COLUMN AND GIVEN SOME WEAK OVERRUNNING FLOW AND F-GEN...MAY SEE
THE DEVELOPMENT OF SCATTERED SHOWERS BY LATE DAY...PARTICULARLY TO
THE W AND S. NOT EXPECTING A WASHOUT...AS SOUNDINGS TAKE SOME TIME
TO MOISTEN AND FORCING IS RELATIVELY WEAK. HIGHS WILL BE SIMILAR
TO PREVIOUS DAYS GIVEN LITTLE CHANGE IN AIRMASS AND LOW LVL COOL
AIR SHOULD KEEP WARM FRONT AT BAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* RAIN POSSIBLE WITH WARM FRONT TUE NIGHT AND WED
* UNSEASONABLY WARM TEMPERATURES POSSIBLE FRI AND SAT
* ANOTHER CHANCE OF RAIN SAT NIGHT AND SUN
MODELS ARE ACTUALLY IN DECENT AGREEMENT THROUGHOUT THE PERIOD. THERE
ARE SOME TIMING DIFFERENCES AS WE GET LATE INTO THE WEEK AND THIS
WEEKEND BUT OVERALL THE PATTERN IS VERY SIMILAR. A WEAK WARM FRONT
MAY DEVELOP SOUTH OF THE REGION BRINGING THE POSSIBILITY OF RAIN
TUESDAY NIGHT AND WEDNESDAY. THEN HIGH PRESSURE DOMINATES THROUGH
MUCH OF THE REST OF THE WEEK. TIMING DIFFERENCES INCREASE AS THE
WEEKEND NEARS AND AN UPPER LEVEL TROUGH STARTS TO IMPACT SOUTHERN
NEW ENGLAND/S WEATHER. MUCH OF THE WORK WEEK SHOULD BE DRY...WITH
THE EXCEPTION OF TUE NIGHT AND WED...THEN A PERIOD OF UNSETTLED
WEATHER RETURNS SUNDAY INTO EARLY NEXT WEEK.
DETAILS...
TUESDAY...HIGH PRESSURE BRINGS DRY SEASONABLE WEATHER TO THE
REGION.
TUESDAY NIGHT THROUGH WEDNESDAY...WEAK WARM FRONT DEVELOPS SOUTH OF
SOUTHERN NEW ENGLAND RESULTING IN LIGHT PRECIPITATION TUESDAY NIGHT
INTO WEDNESDAY. SEASONABLE TEMPERATURES EXPECTED.
THURSDAY THROUGH SATURDAY...SOME DIFFERENCES IN MODEL TIMING TOWARDS
SATURDAY. HOWEVER...THURSDAY AND FRIDAY HIGH PRESSURE IS STILL THE
DOMINANT FEATURE. DRY...SEASONABLE WEATHER IS EXPECTED WITH ABOVE
NORMAL TEMPERATURES POSSIBLE FRIDAY AND SATURDAY.
SUNDAY AND BEYOND...HIGH PRESSURE DEPARTS THE AREA AS AN UPPER LEVEL
TROUGH MOVES INTO THE GREAT LAKES. MODELS ARE LOOKING AT A VERY
DYNAMIC SYSTEM THAT WOULD LIKELY BRING SUBTROPICAL MOISTURE INTO THE
REGION. THIS WOULD RESULT IN A PERIOD OF UNSETTLED WEATHER. THERE
IS VERY LOW CONFIDENCE IN ANY MODEL SOLUTION FOR THIS PERIOD AS IT
IS A WEEK OR MORE OUT IN THE FUTURE...BUT IT WILL WARRANT WATCHING
OVER THE NEXT WEEK.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...HIGH CONFIDENCE.
VFR. W TO NW WINDS WITH GUSTS 20-30 KT FROM MID MORNING THROUGH
THE AFTERNOON. WINDS DIMINISH DURING THE EVENING.
KBOS TAF...HIGH CONFIDENCE IN TAF.
VFR. W TO NW WINDS GUST 20-30 KT MID MORNING INTO THE
AFTERNOON...WEAKENING IN THE EVENING.
KBDL TAF...HIGH CONFIDENCE IN TAF.
VFR. W TO NW WINDS GUST 20-30 KT MID MORNING INTO THE
AFTERNOON...WEAKENING IN THE EVENING.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE TO HIGH CONFIDENCE. WINDS AND SEAS WILL REMAIN BELOW SCA
CRITERIA THROUGH THE PERIOD. PERIODS OF REDUCED VISIBILITY IN FOG
ARE POSSIBLE EACH LATE NIGHT/EARLY MORNING. RAIN SHOWERS ARE
POSSIBLE TUESDAY NIGHT INTO WEDNESDAY.
&&
.MARINE...
HIGH CONFIDENCE.
W TO NW WINDS TODAY WITH GUSTS OF 20-30 KT OVER ALL WATERS.
THEREFORE...SMALL CRAFT ADVISORIES STAND INTO THE EVENING FOR NEAR
SHORE WATERS...AND INTO THE OVERNIGHT FOR OUTER WATERS AS SEAS OF
5-6 FT MAY TAKE SOME TIME TO DIMINISH ON THE OUTER WATERS.
HIGH PRES BUILDS OVER THE WATERS LATE TONIGHT INTO TUE...WHICH
WILL ALLOW WINDS/SEAS TO SUBSIDE AND QUIET BOATING WX TO RETURN.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE TO HIGH CONFIDENCE. WINDS AND SEAS WILL REMAIN BELOW SCA
CRITERIA THROUGH THE PERIOD. PERIODS OF REDUCED VISIBILITY IN FOG
ARE POSSIBLE EACH LATE NIGHT/EARLY MORNING. RAIN SHOWERS ARE
POSSIBLE TUESDAY NIGHT INTO WEDNESDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ231>234.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 7 PM EDT THIS
EVENING FOR ANZ230-235>237-251.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ254>256.
&&
$$
SYNOPSIS...NOCERA/DOODY
NEAR TERM...DOODY
SHORT TERM...DOODY
LONG TERM...NOCERA
AVIATION...NOCERA/DOODY
MARINE...NOCERA/DOODY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
259 AM CDT MON OCT 22 2012
.DISCUSSION...
ISSUED 258 AM CDT MON OCT 22 2012
EARLY MORNING SURFACE MAP SHOWS A WARM FRONT ARCHING NORTHEAST
FROM LOW PRESSURE IN KANSAS...REACHING INTO NORTHEAST IOWA AND
SOUTHERN WISCONSIN. SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING
OVER THE LAST FEW HOURS IN SOUTHWEST IOWA AND NORTHWEST
MISSOURI...AS LOW LEVEL JET FOCUSES IN THAT AREA AHEAD OF A
SHORTWAVE MOVING THROUGH KANSAS. FURTHER EAST...CLOUDS HAVE
OVERSPREAD MOST OF THE CWA...FROM THE SOUTHEAST AND THE WEST.
SHORT TERM...TODAY THROUGH WEDNESDAY...
MAIN FOCUS IN THIS PERIOD IS WITH THE CONTINUED DEVELOPMENT OF THE
CONVECTION TODAY...AS WELL AS TEMPERATURES A GOOD 15 DEGREES ABOVE
NORMAL THE NEXT FEW DAYS.
CONVECTION ACROSS IOWA/MISSOURI EXPECTED TO CONTINUE TO EXPAND
OVER THE NEXT SEVERAL HOURS. MOST OF THE 00Z MODELS FOCUS THE
NORTHWEST HALF OF THE CWA AS MOST LIKELY TO SEE THE ACTIVITY
THROUGH AT LEAST THE MORNING...WITH THE 4KM SPC-WRF LINGERING SOME
ACTIVITY THROUGH THE AFTERNOON NEAR THE I-72 CORRIDOR. AS SUCH...
WILL HAVE THE HIGHEST POPS THIS MORNING...WITH AROUND 30 PERCENT
CHANCES THIS AFTERNOON. HAVE KEPT THE SOUTHEAST CWA MAINLY DRY...
WITH JUST SOME SLIGHT CHANCES.
UPPER WAVE CURRENTLY IN NEW MEXICO WILL LIFT NORTHEAST INTO
MISSOURI BY LATE EVENING. LOW LEVEL JET WILL DEVELOP AGAIN TO OUR
WEST AHEAD OF THE WAVE...HELPING PRODUCE SOME ADDITIONAL
SHOWER/STORM ACTIVITY TONIGHT. SOME OF THE RAIN WILL LINGER INTO
EARLY WEDNESDAY...BUT SHOULD END BY MIDDAY AS THE WAVE PASSES THE
AREA.
TEMPERATURE-WISE...THE RAIN THREAT MAY CAUSE SOME COMPLICATIONS
WITH HIGHS TODAY...BUT STRONG WARM AIR ADVECTION SHOULD GET
TEMPERATURES IN THE MID TO UPPER 70S EVERYWHERE. MAY SEE A COUPLE
80 DEGREE READINGS ACROSS THE SOUTHEAST...WHICH IS MOST LIKELY TO
SEE ANY APPRECIABLE SUNSHINE TODAY. TUESDAY AND WEDNESDAY STILL
LOOKING TO SEE TEMPERATURES NEAR 80 DEGREES...ESPECIALLY ON
WEDNESDAY.
LONG TERM...THURSDAY THROUGH SUNDAY...
TIMING OF A COLD FRONTAL PASSAGE REMAINS A CHALLENGE...AS THE
EVENING MODELS HAVE CONTINUED WITH A SLOWER TREND. MODELS FOCUS ON
THURSDAY NIGHT AS THE MOST LIKELY TIME...WITH A LOT OF THE
ASSOCIATED RAIN ALONG AND BEHIND THE FRONT. MOST RAIN CHANCES ON
THURSDAY WILL BE IN THE AFTERNOON...PRIMARILY WEST OF I-55...WITH
THE RAIN SPREADING EASTWARD IN THE EVENING. BROAD UPPER TROUGH
ACROSS THE PLAINS WILL CONTINUE TO PRODUCE RAIN BEHIND THE FRONT
INTO FRIDAY...WITH THE BEST CHANCES FRIDAY NIGHT AS THE TROUGH
GETS CLOSER TO THE STATE.
THE WEEKEND LOOKS VERY COOL BUT MAINLY DRY. THE LATEST ECMWF HAS
SHIFTED QUITE A BIT AND COME MORE IN LINE WITH THE GFS SOLUTION OF
BOOTING THE PRECIPITATION OUT OF THE AREA SATURDAY MORNING...AND A
SURGE OF CHILLY AIR IN THE UPPER TROUGH WILL RESULT IN HIGH
TEMPERATURES CLOSE TO 50 DEGREES ON BOTH SATURDAY AND SUNDAY.
GEELHART
&&
.AVIATION...
ISSUED 1144 PM CDT SUN OCT 21 2012
A WEAK SHORT-WAVE TROUGH CURRENTLY OVER KANSAS WILL LIFT
NORTHEASTWARD TOWARD THE GREAT LAKES OVER THE NEXT 12
HOURS...SPREADING CLOUDS AND PERHAPS A FEW SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. LATEST HRRR CONTINUES TO SUGGEST
CONVECTION DEVELOPING ALONG THE NOSE OF AN INCREASING LOW-LEVEL
JET AHEAD OF THIS FEATURE WILL REMAIN LARGELY WEST OF THE
MISSISSIPPI RIVER THROUGH 12Z. OTHER HIGH-RES MODELS SUCH AS THE
NAM TRY TO SPREAD AT LEAST ISOLATED CONVECTION INTO THE ILLINOIS
RIVER VALLEY BETWEEN 09Z AND 12Z. GIVEN INITIAL DRY AIRMASS IN
PLACE ACROSS THE AREA...WILL TREND TOWARD THE SLOWER HRRR. AS
AIRMASS GRADUALLY MOISTENS AND UPPER WAVE TRACKS INTO IOWA...A
BAND OF SHOWERS WILL LIKELY DEVELOP WEST OF THE MISSISSIPPI LATE
TONIGHT...THEN LIFT N/NE INTO NORTHERN ILLINOIS MONDAY MORNING.
MODEL CONSENSUS KEEPS STRONGEST FORCING ACROSS THE W/NW KILX
CWA...SO HAVE INCLUDED A TEMPO GROUP FOR -SHRA AND MVFR CEILINGS
AT BOTH KPIA AND KBMI DURING THE 14Z TO 19Z TIME PERIOD. FURTHER
SOUTHEAST AT KDEC AND KCMI...HAVE ONLY MENTIONED VCSH. WINDS WILL
INITIALLY BE FROM THE S/SE AT 5 TO 10MPH TONIGHT...THEN WILL
INCREASE AND GUST TO AROUND 20MPH ON MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1144 PM CDT SUN OCT 21 2012
.DISCUSSION...
ISSUED 846 PM CDT SUN OCT 21 2012
AN APPROACHING UPPER-LEVEL WAVE WILL SPREAD CLOUDS ACROSS CENTRAL
ILLINOIS OVER THE NEXT COUPLE OF HOURS...WITH OVERCAST CONDITIONS
EXPECTED ACROSS THE BOARD AFTER MIDNIGHT. MAIN QUESTION IN THE
SHORT-TERM WILL BE WHETHER ANY SHOWERS CAN DEVELOP ACROSS THE
AREA. LATEST RUN OF THE HRRR CONTINUES TO SHOW CONVECTION FORMING
OVER NORTHERN MISSOURI LATE TONIGHT...THEN LIFTING NORTHEASTWARD
TOWARD WEST-CENTRAL ILLINOIS BY DAWN. 18Z NAM WAS A BIT MORE
AGGRESSIVE IN SPREADING SHOWERS EASTWARD INTO ILLINOIS BETWEEN 09Z
AND 12Z. WITH 00Z KILX UPPER AIR SOUNDING SHOWING QUITE A BIT OF
DRY AIR IN PLACE ABOVE 850MB...WILL CONTINUE TO FAVOR THE SLOWER
HRRR. AS A RESULT...WILL ONLY MAINTAIN LOW CHANCE POPS FOR SHOWERS
ACROSS THE W/SW KILX CWA AFTER MIDNIGHT...WITH DRY CONDITIONS
PERSISTING ACROSS MOST OF THE AREA. HAVE ADJUSTED POPS AND SKY
COVER TO BETTER REFLECT CURRENT TRENDS. HAVE ALSO RAISED OVERNIGHT
LOW TEMPS INTO THE LOWER 60S ALONG/SOUTH OF I-70...WHERE SKIES
HAVE ALREADY BECOME CLOUDY. ZONE UPDATE WILL BE ISSUED SHORTLY.
BARNES
&&
.AVIATION...
ISSUED 1144 PM CDT SUN OCT 21 2012
A WEAK SHORT-WAVE TROUGH CURRENTLY OVER KANSAS WILL LIFT
NORTHEASTWARD TOWARD THE GREAT LAKES OVER THE NEXT 12
HOURS...SPREADING CLOUDS AND PERHAPS A FEW SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. LATEST HRRR CONTINUES TO SUGGEST
CONVECTION DEVELOPING ALONG THE NOSE OF AN INCREASING LOW-LEVEL
JET AHEAD OF THIS FEATURE WILL REMAIN LARGELY WEST OF THE
MISSISSIPPI RIVER THROUGH 12Z. OTHER HIGH-RES MODELS SUCH AS THE
NAM TRY TO SPREAD AT LEAST ISOLATED CONVECTION INTO THE ILLINOIS
RIVER VALLEY BETWEEN 09Z AND 12Z. GIVEN INITIAL DRY AIRMASS IN
PLACE ACROSS THE AREA...WILL TREND TOWARD THE SLOWER HRRR. AS
AIRMASS GRADUALLY MOISTENS AND UPPER WAVE TRACKS INTO IOWA...A
BAND OF SHOWERS WILL LIKELY DEVELOP WEST OF THE MISSISSIPPI LATE
TONIGHT...THEN LIFT N/NE INTO NORTHERN ILLINOIS MONDAY MORNING.
MODEL CONSENSUS KEEPS STRONGEST FORCING ACROSS THE W/NW KILX
CWA...SO HAVE INCLUDED A TEMPO GROUP FOR -SHRA AND MVFR CEILINGS
AT BOTH KPIA AND KBMI DURING THE 14Z TO 19Z TIME PERIOD. FURTHER
SOUTHEAST AT KDEC AND KCMI...HAVE ONLY MENTIONED VCSH. WINDS WILL
INITIALLY BE FROM THE S/SE AT 5 TO 10MPH TONIGHT...THEN WILL
INCREASE AND GUST TO AROUND 20MPH ON MONDAY.
BARNES
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT SUN OCT 21 2012
THE MUCH ABOVE NORMAL WARMTH WILL HIGHLIGHT MOST OF THIS
FORECAST...ALONG WITH PERIODIC RAIN CHANCES THROUGH THE WEEK. A
COLD FRONT WILL USHER IN A SIGNIFICANT AIRMASS CHANGE TO BELOW
NORMAL CONDITIONS FOR LATE NEXT WEEKEND AND INTO THE FOLLOWING
WEEK.
SHORT TERM...TONIGHT THROUGH WEDNESDAY.
AS THE LONG WAVE TROUGH CONTINUES TO SLIDE FARTHER EAST OF
ILLINOIS...MUCH WARMER AIR IS FLOWING NORTH INTO THE AREA AS UPPER
LEVEL RIDGING INCREASES UP THE MISSISSIPPI RIVER VALLEY. WARM
ADVECTION CLOUDS ARE ADVANCING STEADILY NORTHEASTWARD THROUGH
MISSOURI TOWARD SW ILLINOIS. THOSE CLOUDS WILL EVENTUALLY
OVERSPREAD MOST OF OUR COUNTIES BY MONDAY MORNING...AIDED BY AN
INTENSIFYING LOW LEVEL JET. A SURFACE LOW AND 500MB SHORTWAVE IN
KANSAS WILL MOVE NORTHEAST INTO NW MISSOURI/SW IOWA BY 12Z/7AM
MONDAY.
A WARM FRONT EXTENDING EAST OF THE LOW WILL APPROACH CLOSE TO OUR
SW COUNTIES DURING THAT TIME. AS A RESULT OF THAT APPROACHING
ENERGY AND ENHANCE LIFT...WE MAY SEE A FEW SHOWERS OR THUNDERSTORMS
LATE TONIGHT IN OUR W/SW AREA...MAINLY WEST OF PIA TO SPI.
THE PRIMARY FORCING SHOULD REMAIN WEST OF OUR COUNTIES UNTIL
DURING THE DAY ON MONDAY. THE SURFACE LOW WILL LIFT NORTH INTO
IOWA...AND WARM FRONTOGENESIS WILL REDEFINE ACROSS NORTHERN
ILLINOIS BY MONDAY NIGHT. DURING THAT TIME A STEADY STREAM OF
MOISTURE WILL FLOW INTO OUR COUNTIES...EXPANDING CHANCES OF
SHOWERS AND STORMS FARTHER EASTWARD TO INCLUDE MOST OF OUR
COUNTIES NORTH OF I-70. THAT SAME COVERAGE SHOULD CONTINUE INTO
MONDAY NIGHT BEFORE DIMINISHING CHANCES ON TUESDAY AS THE WARM
FRONT LIFTS FARTHER NORTH AWAY FROM C IL. MARGINAL INSTABILITY AND
SHEAR PARAMETERS FROM LATE TONIGHT THROUGH MONDAY NIGHT COULD
ALLOW FOR A FEW STORMS TO PRODUCE SOME HAIL AND GUSTY WINDS...BUT
SEVERE WEATHER DOES NOT APPEAR LIKELY AT THIS TIME.
WE KEPT SLIGHT CHANCE POPS ACROSS ALL OF C IL FOR TUESDAY...AS WE
REMAIN IN AN UNSTABLE MOIST AIRMASS IN THE WARM SECTOR. THE
REMNANTS OF THE TROPICAL SYSTEM OFF THE BAJA OF CALIFORNIA WILL
MOVE ACROSS SOUTHERN IL ON TUESDAY AS WELL...HELPING TO PROVIDE
SOME DIFFUSE LIFT ACROSS THE AREA.
BY WEDNESDAY...WE SHOULD SEE DRY CONDITIONS RETURN AS SHORTWAVE
ENERGY AND FORCING FOR PRECIP REMAINS WEST AND NORTH OF C IL.
ADDITIONAL SUNSHINE ON WEDNESDAY WILL HELP BOOST HIGH TEMPS INTO
THE LOW 80S IN OUR SW COUNTIES...WITH MID TO UPPER 70S ELSEWHERE.
LONG TERM...THURSDAY THROUGH SUNDAY.
AN APPROACHING COLD FRONT FOR LATE WEEK HAS BEEN SLOWED DOWN BY
THE MODELS WITH EACH OF THE LAST 3 MODEL CYCLES. THAT WOULD HELP
BOOST THURSDAY HIGH TEMPS WELL ABOVE NORMAL FOR THE LAST TIME THIS
WEEK...AND KEEP PRECIP CHANCES HELD OFF UNTIL THURSDAY AFTERNOON
AT THE EARLIEST...AND MOST LIKELY UNTIL THURSDAY NIGHT. WE BEGAN
TO SHOW THAT TIMING TREND BY RAISING HIGH TEMPS IN THE SE HALF OF
OUR COUNTIES ON THURS...AND PUSH BACK CHANCE POPS TO THUR
AFTERNOON AND MAINLY NW OF THE IL RIVER.
AS THE FRONT MOVES INTO SOUTHEAST IL FRIDAY NIGHT...A SECONDARY
WAVE IS FORECAST TO QUICKLY MOVE OUT OF THE PLAINS AND UP ACROSS
ILLINOIS FRI NIGHT AND SATURDAY. TO REFLECT THAT CHANGE IN THE
EXTENDED FORECAST...WE INCREASED POPS FOR RAIN SHOWERS FRIDAY
NIGHT AND SATURDAY. BY SUNDAY...AND MUCH COOLER AIR IS EXPECTED TO
ADVANCE INTO ILLINOIS...STARTING AND EXTENDED PERIOD OF BELOW
NORMAL TEMPS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
400 AM CDT MON OCT 22 2012
...UPDATED FOR LONG TERM...
.SYNOPSIS...
ISSUED AT 1100 PM CDT SUN OCT 21 2012
THE 22.00Z 250 HPA RAOB MAP SHOWED JET LEVEL WINDS AROUND 100 KT ACROSS
THE NORTHERN PORTION OF THE COUNTRY. A SOUTHWESTERLY JET WAS OBSERVED
FROM THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS. DOWNSTREAM, THIS
FLOW TURNED NORTHWESTERLY ACROSS THE GREAT LAKES. AT 500 HPA, A LARGE
TROF WAS LOCATED JUST WEST OF BRITISH COLUMBIA. ANOTHER TROF WAS FOUND
ACROSS NORTHERN SASKATCHEWAN. VERY COLD MID LEVEL TEMPERATURES AROUND
-33 TO -36 DEG C WERE ASSOCIATED WITH THESE TWO DISTURBANCES. SOME MID
LEVEL MOISTURE WAS NOTED ACROSS THE CENTRAL AND NORTHERN ROCKIES. THERE
WAS AN OPEN TROF MOVING NORTHEAST ACROSS THE DESERT SW/SONORA. SHORTWAVE
RIDGING WAS LOCATED ACROSS THE MIDWEST/LOWER MISSISSIPPI RIVER VALLEY.
AT 700 AND 850 HPA, THE WARM PLUME STILL PREVAILED ACROSS THE CENTRAL
AND SOUTHERN PLAINS. SOME LOW LEVEL MOISTURE ADVECTION WAS OBSERVED
ACROSS OKLAHOMA/EASTERN KANSAS. A DOWNSLOPE WARM AND DRY PLUME WAS VERY
OBVIOUS PER THE KDDC RAOB. AT THE SFC, A COLD FRONT EXTENDED FROM MINNESOTA
TO WESTERN KANSAS. DEWPOINTS WERE RUNNING IN THE 60S DEG F AHEAD OF
THIS BOUNDARY FROM TEXAS TO IOWA.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 321 AM CDT MON OCT 22 2012
COMPLICATED FORECAST TODAY WITH HIGH TEMPERATURE BUST POTENTIAL,
PARTICULARLY ALONG INTERSTATE 70. LOW STRATUS IS BEGINNING TO INCREASE
IN AERIAL COVERAGE PER THE 11U-3.9U SATELLITE CHANNEL AND KHYS IS ALREADY
IN THE LOW STRATUS/IFR CONDITIONS. FOR THE TEMPERATURE FORECAST, WILL
PUT MORE OF AN EMPHASIS ON THE 00Z NAM/ARW-NMM MESOSCALE MODELS WHICH
KEEPS CENTRAL KANSAS UNDER STRATUS AND RESULTANT COOLER TEMPERATURES.
THE ARW-NMM IS VERY AGGRESSIVE WITH COOLER TEMPERATURES AND KEEPS KHYS
IN THE 50S DEG F. THE NAM SUGGESTS MID 60S DEG F. WILL COMPROMISE BETWEEN
THE PREVIOUS FORECAST AND THE NEW 00Z DATA AND KEEP TEMPERATURES AROUND
70 DEG F ACROSS WEST CENTRAL AND CENTRAL KANSAS. THERE IS LARGE UNCERTAINTY
ON HOW LONG THE STRATUS WILL STICK AROUND AS ISENTROPIC DOWNGLIDE IS
EVENTUALLY FORECAST. WILL ALSO KEEP PATCHY FOG IN THE WX GRIDS GENERALLY
EAST OF HIGHWAY 283 THIS MORNING. HRRR SUGGESTS DENSE FOG THIS MORNING
BUT WILL GO WITH PATCHY FOR NOW AS CURRENT OBSERVATIONS SHOW THAT THE
HRRR MODEL IS BEING A BIT AGGRESSIVE ON FORECAST VISIBILITIES FOR THE
CURRENT HOUR. THERE ALSO COULD BE SOME DRIZZLE ALONG I-70 BUT NOT SURE
OF THE SATURATED LAYER WILL BE THICK ENOUGH AS BUFR SOUNDINGS ARE AROUND
2000 FEET INSTEAD OF THE 3000 FEET IDEAL THICKNESS. THE WARMEST TEMPERATURES
ARE EXPECTED ALONG THE FRONTAL BOUNDARY ACROSS SOUTH CENTRAL KANSAS
WHERE 80S DEG ARE LIKELY AS A NARROW WEDGE OF WARMER 850 HPA TEMPERATURES
/DOWNSLOPE WINDS ARE FORECAST.
BY THIS EVENING, THE AFOREMENTIONED BOUNDARY WILL RETURN NORTHWARD AS
A WARM FRONT. WILL GO WITH WARMER MINIMUM TEMPERATURES ACROSS SOUTH
CENTRAL KANSAS AS FAIRLY HIGH SURFACE DEWPOINTS ADVECT NORTHWARD AGAIN.
PATCHY FOG LOOKS POSSIBLE AGAIN TOMORROW MORNING VIA BUFR SOUNDINGS
/MOS GUIDANCE/ AND BOUNDARY LAYER RELATIVE HUMIDITY PROGS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 AM CDT MON OCT 22 2012
MAIN CONCERNS IN THIS PERIOD ARE FIRE WEATHER CONDITIONS FOR TUESDAY
AND WEDNESDAY AFTERNOONS IN THE SOUTHWEST FA FROM NESS CITY TO DODGE
CITY AND WEST, CHANCES OF THUNDERSTORMS IN THE EAST FA FROM HAYS TO
COLDWATER AND EAST WITH A COLD FRONT FOR WEDNESDAY NIGHT INTO
THURSDAY MORNING, AND THE POSSIBILITY FOR BELOW FREEZING
TEMPERATURES FOR NEXT SATURDAY AND SUNDAY MORNINGS.
FOR TUESDAY AND WEDNESDAY SOUTHWEST AND SOUTH CENTRAL KANSAS WILL BE
IN THE WARM SECTOR AHEAD OF A STRONG UPPER LEVEL BROAD TROUGH MOVING
FROM THE WESTERN CONUS AND INTO THE ROCKIES AND 4 CORNERS REGION. A
DRYLINE IS FORECAST TO SET UP FROM WAKEENEY TO DODGE CITY AND MEADE,
THEN PROGRESS EASTWARD DURING THE AFTERNOON. THE SAME SITUATION
REPEATS ITSELF ON WEDNESDAY AFTERNOON. SURFACE LOW PRESSURE IN THE
LEE OF THE ROCKIES WILL DEEPEN INTO WEDNESDAY WITH THE STRONGEST
PRESSURE GRADIENT ON WEDNESDAY AFTERNOON. BY TUESDAY AFTERNOON THE
SOUTH TO SOUTHWEST WINDS COULD BE FROM 15 TO 25 MPH AND THEN 20 TO
30 MPH ON WEDNESDAY AFTERNOON. RELATIVE HUMIDITIES SHOULD FALL BELOW
15 TO 20 PERCENT BOTH AFTERNOONS, SO WILL HAVE TO KEEP A CLOSE EYE
OUT FOR A FIRE WEATHER WATCH ESPECIALLY FOR WEDNESDAY AFTERNOON FOR
OUR SOUTHWESTERN COUNTIES. SINCE TUESDAY AFTERNOON WINDS ARE NOT AS
STRONG WILL NOT GO WITH A WATCH AT THIS TIME. AFTERNOON HIGHS SHOULD
BE IN THE MID TO UPPER 80S FOR BOTH DAYS. OVERNIGHT LOWS ARE
FORECAST TO BE VERY MILD ON TUESDAY NIGHT WITH SOUTH BREEZES AT 10
TO 20 MPH.
THEN FOR WEDNESDAY NIGHT AND THURSDAY THE BROAD UPPER LEVEL TROUGH
MOVES ACROSS THE PLAINS PUSHING A STRONG COLD FRONT ACROSS WESTERN
KANSAS. WITH GOOD MOISTURE AHEAD OF THE COLD FRONT A FEW STRONG TO
POSSIBLY SEVERE THUNDERSTORMS MAY DEVELOP ALONG AND AHEAD OF THE
COLD FRONT. THERE WILL BE PLENTY OF LAYER WIND SHEAR WITH FORECAST
CAPE AROUND 1000 J/KG. THE AREA FROM HAYS SOUTH TO GREENSBURG AND
COLDWATER AND EAST HAS THE BEST CHANCES FOR THUNDERSTORMS INTO LATE
WEDNESDAY NIGHT. NORTH WINDS OF 15 TO 25 MPH AND GUSTY WILL FOLLOW
THE FRONT THAT SHOULD BE MOVING LASTLY THROUGH MEDICINE LODGE BY 7
AM THURSDAY MORNING. THURSDAY MORNING LOWS ARE FORECAST TO RANGE
FROM THE MID 40S WEST TO THE MID 50S EAST FROM SAINT JOHN TO
MEDICINE LODGE. DAYTIME HIGHS ON THURSDAY WILL ONLY BE IN THE MID TO
UPPER 50S NORTH TO MID 60S SOUTH AS MUCH COLDER SURFACE HIGH
PRESSURE FOLLOWS THE COLD FRONT. THURSDAY NIGHT LOWS LOOK TO BE IN
THE MID TO UPPER 30S WITH SOME MIXING.
FOR FRIDAY A SECONDARY UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE
PLAINS WITH MAINLY MID AND HIGH LEVEL CLOUDINESS. THE GFS LOOKS WAY
OVER SATURATED AND IS A TYPICAL MODEL BIAS WHILE THE NEW ECMWF LOOK
VERY DRY THROUGH THE LAYER. WILL GO AHEAD AND HEDGE TOWARD THE ECMWF
AND TAKE POPS DOWN TO SILENT. A STRONG RIDGE OF SURFACE HIGH
PRESSURE WILL REINFORCE ITSELF INTO THE WESTERN HIGH PLAINS WITH
HIGHS ONLY IN THE UPPER 40S TO LOWER 50S.
FOR THE WEEKEND A VERY DRY AIRMASS IS FORECAST WITH DEWPOINTS IN THE
20`S. DAYTIME HIGHS FOR SATURDAY ARE AGAIN ONLY IN THE UPPER 40S TO
LOWER 50S THEN WARM INTO THE 50S ON SUNDAY. BY SATURDAY MORNING THE
MODELS ARE FORECASTING A SHARP RIDGE AXIS OF HIGH PRESSURE WITH
LIGHT WINDS AND CLEAR SKIES. ON SUNDAY MORNING THE GFS HAS THE RIDGE
MOVING EAST INTO CENTRAL KANSAS WHILE THE ECMWF HAS IT AGAIN OVER
SOUTHWEST KANSAS. IF THE MODELS ARE CORRECT THERE IS A GOOD
POSSIBILITY OF A FREEZE OR KILLING FREEZE ON BOTH EARLY MORNINGS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1200 AM CDT MON OCT 22 2012
SOMEWHAT PROBLEMATIC 06Z TAFS AS THERE IS UNCERTAINTY IN HOW LOW CIGS
WILL BECOME ASSOCIATED WITH WRAP AROUND CLOUDS IN THE WAKE OF A WEAK
FRONT. THE HRRR IS SUGGESTING LIFR CIGS, HOWEVER, OBSERVATIONS ARE NOT
TRENDING THE MODEL OUT CURRENTLY SO AM A LITTLE DUBIOUS OF THIS SOLUTION.
HAVE TRENDED THE TAFS UPWARDS AND BROUGHT IN A LOW VFR CLOUD DECK THROUGH
THE OVERNIGHT HOURS. OTHERWISE, VFR CONDITIONS EXPECTED FOR THE REST
OF TODAY. WINDS WILL EVENTUALLY BECOME SOUTHERLY THIS AFTERNOON AS A
WARM FRONT MOVES NORTHWARD ACROSS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 75 52 87 60 / 0 0 0 0
GCK 74 47 87 56 / 0 0 0 0
EHA 78 50 87 57 / 0 0 0 0
LBL 79 48 88 55 / 0 0 0 0
HYS 69 52 85 56 / 0 0 0 0
P28 84 61 90 65 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
321 AM CDT MON OCT 22 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1100 PM CDT SUN OCT 21 2012
THE 22.00Z 250 HPA RAOB MAP SHOWED JET LEVEL WINDS AROUND 100 KT ACROSS
THE NORTHERN PORTION OF THE COUNTRY. A SOUTHWESTERLY JET WAS OBSERVED
FROM THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS. DOWNSTREAM, THIS
FLOW TURNED NORTHWESTERLY ACROSS THE GREAT LAKES. AT 500 HPA, A LARGE
TROF WAS LOCATED JUST WEST OF BRITISH COLUMBIA. ANOTHER TROF WAS FOUND
ACROSS NORTHERN SASKATCHEWAN. VERY COLD MID LEVEL TEMPERATURES AROUND
-33 TO -36 DEG C WERE ASSOCIATED WITH THESE TWO DISTURBANCES. SOME MID
LEVEL MOISTURE WAS NOTED ACROSS THE CENTRAL AND NORTHERN ROCKIES. THERE
WAS AN OPEN TROF MOVING NORTHEAST ACROSS THE DESERT SW/SONORA. SHORTWAVE
RIDGING WAS LOCATED ACROSS THE MIDWEST/LOWER MISSISSIPPI RIVER VALLEY.
AT 700 AND 850 HPA, THE WARM PLUME STILL PREVAILED ACROSS THE CENTRAL
AND SOUTHERN PLAINS. SOME LOW LEVEL MOISTURE ADVECTION WAS OBSERVED
ACROSS OKLAHOMA/EASTERN KANSAS. A DOWNSLOPE WARM AND DRY PLUME WAS VERY
OBVIOUS PER THE KDDC RAOB. AT THE SFC, A COLD FRONT EXTENDED FROM MINNESOTA
TO WESTERN KANSAS. DEWPOINTS WERE RUNNING IN THE 60S DEG F AHEAD OF
THIS BOUNDARY FROM TEXAS TO IOWA.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 321 AM CDT MON OCT 22 2012
COMPLICATED FORECAST TODAY WITH HIGH TEMPERATURE BUST POTENTIAL,
PARTICULARLY ALONG INTERSTATE 70. LOW STRATUS IS BEGINNING TO INCREASE
IN AERIAL COVERAGE PER THE 11U-3.9U SATELLITE CHANNEL AND KHYS IS ALREADY
IN THE LOW STRATUS/IFR CONDITIONS. FOR THE TEMPERATURE FORECAST, WILL
PUT MORE OF AN EMPHASIS ON THE 00Z NAM/ARW-NMM MESOSCALE MODELS WHICH
KEEPS CENTRAL KANSAS UNDER STRATUS AND RESULTANT COOLER TEMPERATURES.
THE ARW-NMM IS VERY AGGRESSIVE WITH COOLER TEMPERATURES AND KEEPS KHYS
IN THE 50S DEG F. THE NAM SUGGESTS MID 60S DEG F. WILL COMPROMISE BETWEEN
THE PREVIOUS FORECAST AND THE NEW 00Z DATA AND KEEP TEMPERATURES AROUND
70 DEG F ACROSS WEST CENTRAL AND CENTRAL KANSAS. THERE IS LARGE UNCERTAINTY
ON HOW LONG THE STRATUS WILL STICK AROUND AS ISENTROPIC DOWNGLIDE IS
EVENTUALLY FORECAST. WILL ALSO KEEP PATCHY FOG IN THE WX GRIDS GENERALLY
EAST OF HIGHWAY 283 THIS MORNING. HRRR SUGGESTS DENSE FOG THIS MORNING
BUT WILL GO WITH PATCHY FOR NOW AS CURRENT OBSERVATIONS SHOW THAT THE
HRRR MODEL IS BEING A BIT AGGRESSIVE ON FORECAST VISIBILITIES FOR THE
CURRENT HOUR. THERE ALSO COULD BE SOME DRIZZLE ALONG I-70 BUT NOT SURE
OF THE SATURATED LAYER WILL BE THICK ENOUGH AS BUFR SOUNDINGS ARE AROUND
2000 FEET INSTEAD OF THE 3000 FEET IDEAL THICKNESS. THE WARMEST TEMPERATURES
ARE EXPECTED ALONG THE FRONTAL BOUNDARY ACROSS SOUTH CENTRAL KANSAS
WHERE 80S DEG ARE LIKELY AS A NARROW WEDGE OF WARMER 850 HPA TEMPERATURES
/DOWNSLOPE WINDS ARE FORECAST.
BY THIS EVENING, THE AFOREMENTIONED BOUNDARY WILL RETURN NORTHWARD AS
A WARM FRONT. WILL GO WITH WARMER MINIMUM TEMPERATURES ACROSS SOUTH
CENTRAL KANSAS AS FAIRLY HIGH SURFACE DEWPOINTS ADVECT NORTHWARD AGAIN.
PATCHY FOG LOOKS POSSIBLE AGAIN TOMORROW MORNING VIA BUFR SOUNDINGS
/MOS GUIDANCE/ AND BOUNDARY LAYER RELATIVE HUMIDITY PROGS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 238 PM CDT SUN OCT 21 2012
MEDIUM RANGE MODELS INDICATE A SMALL UPPER LEVEL SHORTWAVE LIFTING
NORTHEAST OUT OF MISSOURI INTO THE SOUTHERN GREAT LAKES REGION
TUESDAY GIVING WAY TO A PREVAILING SOUTHWESTERLY FLOW ALOFT ACROSS
THE WESTERN HIGH PLAINS. ALONG WITH THE LACK OF ANY DEEP LOW LEVEL
MOISTURE PRESENT, GENERALLY DRY CONDITIONS CAN BE EXPECTED ACROSS
WESTERN KANSAS THROUGH AT LEAST LATE WEDNESDAY AFTERNOON. A LARGER
SCALE UPPER LEVEL TROUGH IS THEN EXPECTED TO TRACK EASTWARD
ACROSS THE INTERMOUNTAIN WEST WEDNESDAY PUSHING INTO THE WESTERN
HIGH PLAINS THURSDAY BRINGING THE POSSIBILITY FOR SHOWERS AND
THUNDERSTORMS TO THE CENTRAL PLAINS, INCLUDING PORTIONS OF KANSAS.
AN ATTENDANT COLD FRONT TO THE APPROACHING UPPER LEVEL SYSTEM IS
PROJECTED TO PUSH SOUTHEAST INTO WESTERN KANSAS DURING THE LATE
WEDNESDAY TO THURSDAY TIME FRAME. MEANWHILE, AMPLE LOW LEVEL
MOISTURE WILL BE ADVECTING NORTHWARD ACROSS OKLAHOMA INTO EASTERN
AND PORTIONS OF CENTRAL KANSAS AHEAD OF A DRYLINE EXPECTED TO
EXTEND FROM A SURFACE LOW IN CENTRAL KANSAS SOUTHWARD INTO THE
EASTERN TEXAS PANHANDLE/WESTERN OKLAHOMA REGION. SHOWERS AND
THUNDERSTORMS ARE LIKELY TO DEVELOP ALONG THE FRONTAL BOUNDARY
WEDNESDAY NIGHT INTO THURSDAY AS A STRONG UPPER LEVEL JET CYCLES
THROUGH THE TROUGH AXIS AND NUDGES EAST INTO THE WESTERN HIGH
PLAINS. THE QUESTION WILL BE HOW FAR SOUTHWEST ALONG THE BOUNDARY
INTO KANSAS WILL CONVECTION EXTEND AND THE TIMING OF THE SYSTEM
OVERALL. IT LOOKS AS THOUGH THE BEST LOW LEVEL CONVERGENCE WILL BE
NORTHEAST OF THE PROJECTED SURFACE LOW IN WESTERN/CENTRAL KANSAS.
SO, WITH TIMING STILL AN ISSUE, WILL RETAIN THE SLIGHT POPS
ALREADY INTRODUCED ACROSS CENTRAL KANSAS WEDNESDAY NIGHT INTO
EARLY THURSDAY. ANOTHER CHANCE FOR PRECIP EXISTS LATE IN THE WEEK
AS THE BROAD UPPER LEVEL TROUGH TRANSITIONS EAST ACROSS THE
CENTRAL PLAINS.
TEMPERATURES WILL BE WELL ABOVE NORMAL TUESDAY AS A LEE SIDE TROUGH
OF LOW PRESSURE QUICKLY DEVELOPS ACROSS EASTERN COLORADO HELPING
LIFT A STALLED FRONTAL BOUNDARY BACK NORTH ACROSS WESTERN KANSAS
BY TUESDAY AFTERNOON. THIS WILL RETURN A LOW LEVEL SOUTHERLY FLOW
TO WESTERN KANSAS ENHANCING WARM AIR ADVECTION BACK INTO THE
AREA. THE NAM, GFS, AND ECMWF SHOW H85 TEMPERATURES RANGING AROUND
THE LOWER TO MID 20S(C) TUESDAY AFTERNOON WITH THE WARMEST
TEMPERATURES IN EXTREME SOUTHWEST KANSAS. ALONG WITH PLENTY OF
SUNSHINE, WIDESPREAD 80S(F) ARE EXPECTED FOR HIGHS TUESDAY
AFTERNOON WITH NEAR 90F POSSIBLE IN SOME LOCATIONS IN SOUTHWEST
AND POSSIBLY SOUTH CENTRAL KANSAS. A SIGNIFICANT COOLING TREND
WILL THEN TAKE PLACE BY FRIDAY AS THE BROAD UPPER LEVEL TROUGH
PUSHES EAST THROUGH THE INTERMOUNTAIN WEST INTO THE WESTERN HIGH
PLAINS. AS MENTIONED EARLIER, AN ATTENDANT COLD FRONT TO THIS
SYSTEM IS EXPECTED TO PUSH INTO AND ACROSS WESTERN KANSAS BY LATE
FRIDAY ALLOWING MUCH COLDER AIR TO SURGE SOUTHWARD INTO THE
REGION. BELOW NORMAL TEMPERATURES ARE LIKELY BY THIS WEEKEND
AS A RESULT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1200 AM CDT MON OCT 22 2012
SOMEWHAT PROBLEMATIC 06Z TAFS AS THERE IS UNCERTAINTY IN HOW LOW CIGS
WILL BECOME ASSOCIATED WITH WRAP AROUND CLOUDS IN THE WAKE OF A WEAK
FRONT. THE HRRR IS SUGGESTING LIFR CIGS, HOWEVER, OBSERVATIONS ARE NOT
TRENDING THE MODEL OUT CURRENTLY SO AM A LITTLE DUBIOUS OF THIS SOLUTION.
HAVE TRENDED THE TAFS UPWARDS AND BROUGHT IN A LOW VFR CLOUD DECK THROUGH
THE OVERNIGHT HOURS. OTHERWISE, VFR CONDITIONS EXPECTED FOR THE REST
OF TODAY. WINDS WILL EVENTUALLY BECOME SOUTHERLY THIS AFTERNOON AS A
WARM FRONT MOVES NORTHWARD ACROSS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 75 52 87 60 / 0 0 0 0
GCK 74 47 87 56 / 0 0 0 0
EHA 78 50 87 57 / 0 0 0 0
LBL 79 48 88 55 / 0 0 0 0
HYS 69 52 85 56 / 0 0 0 0
P28 84 61 90 65 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1120 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 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1120 PM MDT SUN OCT 21 2012
THE MAIN FORECAST CONCERN IS THE POSSIBILITY OF STRATUS ADVECTING
FROM THE NORTH OR DEVELOPING OVER KMCK/KGLD. HRRR/SREF MODELS
INDICATE THAT MVFR CEILINGS WILL BE OVER KMCK FROM 09Z-16Z...THOUGH
ARE LESS AGGRESSIVE AT KGLD. LATEST FOG SATELLITE IMAGERY SHOWS
LOW CLOUDS DEVELOPING OVER NORTH CENTRAL NEBRASKA. EXPECT LOW
LEVEL MOISTURE TO DECREASE SLIGHTLY EARLY IN THE MORNING...BUT DEW
POINT DEPRESSIONS WILL BE LOW ENOUGH FOR MVFR CEILINGS AT KMCK.
LOW CLOUDS ARE NOT AS LIKELY FURTHER WEST INCLUDING AT KGLD. ANY
CLOUDS OVER THE AREA WILL DISSIPATE BY 16Z WITH VFR CONDITIONS
AFTER THAT.
&&
.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 WARRANT 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
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...MENTZER
FIRE WEATHER...JTL
CLIMATE...JTL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT MON OCT 22 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 1100 PM CDT SUN OCT 21 2012
THE 22.00Z 250 HPA RAOB MAP SHOWED JET LEVEL WINDS AROUND 100 KT ACROSS
THE NORTHERN PORTION OF THE COUNTRY. A SOUTHWESTERLY JET WAS OBSERVED
FROM THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS. DOWNSTREAM, THIS
FLOW TURNED NORTHWESTERLY ACROSS THE GREAT LAKES. AT 500 HPA, A LARGE
TROF WAS LOCATED JUST WEST OF BRITISH COLUMBIA. ANOTHER TROF WAS FOUND
ACROSS NORTHERN SASKATCHEWAN. VERY COLD MID LEVEL TEMPERATURES AROUND
-33 TO -36 DEG C WERE ASSOCIATED WITH THESE TWO DISTURBANCES. SOME MID
LEVEL MOISTURE WAS NOTED ACROSS THE CENTRAL AND NORTHERN ROCKIES. THERE
WAS AN OPEN TROF MOVING NORTHEAST ACROSS THE DESERT SW/SONORA. SHORTWAVE
RIDGING WAS LOCATED ACROSS THE MIDWEST/LOWER MISSISSIPPI RIVER VALLEY.
AT 700 AND 850 HPA, THE WARM PLUME STILL PREVAILED ACROSS THE CENTRAL
AND SOUTHERN PLAINS. SOME LOW LEVEL MOISTURE ADVECTION WAS OBSERVED
ACROSS OKLAHOMA/EASTERN KANSAS. A DOWNSLOPE WARM AND DRY PLUME WAS VERY
OBVIOUS PER THE KDDC RAOB. AT THE SFC, A COLD FRONT EXTENDED FROM MINNESOTA
TO WESTERN KANSAS. DEWPOINTS WERE RUNNING IN THE 60S DEG F AHEAD OF
THIS BOUNDARY FROM TEXAS TO IOWA.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 117 PM CDT SUN OCT 21 2012
AS NOTED ABOVE IN THE SYNOPSIS, A COLD FRONT CAN BE DETECTED FROM
EASTERN DAKOTAS SOUTHWESTWARD TO NEAR NORTHEASTERN COLORADO, THEN
BACK WEST TO NORTHERN UTAH. THE UPPER JET WAS NEARLY PARALLEL AND
JUST NORTH OF THE FRONT, ACROSS IDAHO, SOUTH DAKOTA AND
INTERSECTING THE BOUNDARY LAYER FRONT NEAR A SURFACE LOW PRESSURE
CENTER OVER EXTREME SOUTHWEST SOUTH DAKOTA. A WARM FRONT ALSO
EXTENDED SOUTHEAST FROM THE SOUTHEASTERN SOUTH DAKOTA LOW, EXTENDING
SOUTHEAST INTO SOUTHEASTERN MISSOURI. A WEAK SURFACE LOW WAS OVER
CENTRAL KANSAS AT 18Z, WITH A TROUGH SOUTH-SOUTHWESTWARD TROUGH THE
TEXAS PANHANDLE INTO MEXICO. A SMALL SCALE HIGH PRESSURE AREA WAS
OVER SOUTHERN COLORADO. SINCE UPPER LEVEL FORCING DOES NOT SUPPORT
THE FRONT MOVING SOUTH VERY FAST, WILL STAY PRETTY CLOSE TO THE
PREVIOUS FORECAST OF BRINGING THE FRONT SOUTHEASTWARD INTO THE HYS
AREA BY 06Z, THE GCK AREA BY 07Z AND THE DDC AREA BY 09Z, AND NOT
TROUGH THE P28 AREA BEFORE 12Z. THERE ARE NOT ANY STRONG PRESSURE
RISES FORECAST BEHIND THE FROPA, SO DO NOT EXPECT ANY STRONG WINDS
BEHIND THE FRONT, AS HAS HAPPENED WITH RECENT COLD FRONT PASSAGES.
MID AND HIGH CLOUDS MOVING SOUTH INTO OUR FORECAST AREA WILL SLOW
DOWN ANY RADIATIONAL COOLING AFFECT THE FROPA MIGHT HAVE HAD.
PARTLY TO MOSTLY CLOUDY SKIES SHOULD BE OVER OUR SOUTHERN 2/3RDS OF
THE CWA FROM ABOUT 08Z TO 16Z MONDAY, BEFORE SUBSIDENCE FROM THE
HIGH PRESSURE BUILDING IN SCATTERS OUT THE CLOUDS BY MONDAY
MID-MORNING. ALSO, THE FRONT WILL NOT BRING VERY COLD AIR DOWN INTO
WESTERN KANSAS, SO MINIMUM TEMPERATURES TONIGHT WILL BE THE COOLEST
IN MY NORTHWEST ZONES NEAR SYRACUSE AND SCOTT CITY IN THE LOWER
40S. TEMPERATURES IN LBL AND DDC MAY ONLY SINK TO THE MID 40S DUE
TO TIMING OF THE COLD FRONT PASSAGE, WHILE PRATT AND COLDWATER
WILL JUST COOL TO THE MID 50S. THE FRONT MAY NOT GET PAST MY
SOUTHEAST ZONES BEFORE MONDAY MORNING.
MONDAY WILL BE COOLER BEHIND THE FRONT, WITH SURFACE HIGH PRESSURE
BUILDING IN FROM THE NORTH. A LOW PRESSURE AREA OVER THE PANHANDLE
WILL LIKELY CAUSE THE FRONT TO MIGRATE BACK NORTHWARD MONDAY
AFTERNOON AS A WARM FRONT. THE NAM MODEL SHOWS THIS NORTH MOVING
WARM FRONT WELL MONDAY AFTERNOON, IN THE 1000-880MB THICKNESS
PROGS. MORNING CLOUDS WILL SLOW UP THE WARMING, AND COOLER LOW
LEVEL AIR WILL BRING MAX TEMPS IN THE LOWER TO MID 70S ACROSS OUR
AREA NORTH OF 1-70, WITH LOWER 80S LIKELY IN THE MEDICINE LODGE
AREA PRIOR TO THE COLD FRONTAL PASSAGE. WINDS MAY BE FROM THE
NORTH AT 10 TO 20 MPH JUST BEHIND THE FRONT FOR A FEW HOURS, BUT
HIGH PRESSURE ON MONDAY AND THE RETURNING WARM FRONT WILL SUPPRESS
A PRESSURE GRADIENT, AND LIGHT WINDS SHOULD RETURN MONDAY
AFTERNOON.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 238 PM CDT SUN OCT 21 2012
MEDIUM RANGE MODELS INDICATE A SMALL UPPER LEVEL SHORTWAVE LIFTING
NORTHEAST OUT OF MISSOURI INTO THE SOUTHERN GREAT LAKES REGION
TUESDAY GIVING WAY TO A PREVAILING SOUTHWESTERLY FLOW ALOFT ACROSS
THE WESTERN HIGH PLAINS. ALONG WITH THE LACK OF ANY DEEP LOW LEVEL
MOISTURE PRESENT, GENERALLY DRY CONDITIONS CAN BE EXPECTED ACROSS
WESTERN KANSAS THROUGH AT LEAST LATE WEDNESDAY AFTERNOON. A LARGER
SCALE UPPER LEVEL TROUGH IS THEN EXPECTED TO TRACK EASTWARD
ACROSS THE INTERMOUNTAIN WEST WEDNESDAY PUSHING INTO THE WESTERN
HIGH PLAINS THURSDAY BRINGING THE POSSIBILITY FOR SHOWERS AND
THUNDERSTORMS TO THE CENTRAL PLAINS, INCLUDING PORTIONS OF KANSAS.
AN ATTENDANT COLD FRONT TO THE APPROACHING UPPER LEVEL SYSTEM IS
PROJECTED TO PUSH SOUTHEAST INTO WESTERN KANSAS DURING THE LATE
WEDNESDAY TO THURSDAY TIME FRAME. MEANWHILE, AMPLE LOW LEVEL
MOISTURE WILL BE ADVECTING NORTHWARD ACROSS OKLAHOMA INTO EASTERN
AND PORTIONS OF CENTRAL KANSAS AHEAD OF A DRYLINE EXPECTED TO
EXTEND FROM A SURFACE LOW IN CENTRAL KANSAS SOUTHWARD INTO THE
EASTERN TEXAS PANHANDLE/WESTERN OKLAHOMA REGION. SHOWERS AND
THUNDERSTORMS ARE LIKELY TO DEVELOP ALONG THE FRONTAL BOUNDARY
WEDNESDAY NIGHT INTO THURSDAY AS A STRONG UPPER LEVEL JET CYCLES
THROUGH THE TROUGH AXIS AND NUDGES EAST INTO THE WESTERN HIGH
PLAINS. THE QUESTION WILL BE HOW FAR SOUTHWEST ALONG THE BOUNDARY
INTO KANSAS WILL CONVECTION EXTEND AND THE TIMING OF THE SYSTEM
OVERALL. IT LOOKS AS THOUGH THE BEST LOW LEVEL CONVERGENCE WILL BE
NORTHEAST OF THE PROJECTED SURFACE LOW IN WESTERN/CENTRAL KANSAS.
SO, WITH TIMING STILL AN ISSUE, WILL RETAIN THE SLIGHT POPS
ALREADY INTRODUCED ACROSS CENTRAL KANSAS WEDNESDAY NIGHT INTO
EARLY THURSDAY. ANOTHER CHANCE FOR PRECIP EXISTS LATE IN THE WEEK
AS THE BROAD UPPER LEVEL TROUGH TRANSITIONS EAST ACROSS THE
CENTRAL PLAINS.
TEMPERATURES WILL BE WELL ABOVE NORMAL TUESDAY AS A LEE SIDE TROUGH
OF LOW PRESSURE QUICKLY DEVELOPS ACROSS EASTERN COLORADO HELPING
LIFT A STALLED FRONTAL BOUNDARY BACK NORTH ACROSS WESTERN KANSAS
BY TUESDAY AFTERNOON. THIS WILL RETURN A LOW LEVEL SOUTHERLY FLOW
TO WESTERN KANSAS ENHANCING WARM AIR ADVECTION BACK INTO THE
AREA. THE NAM, GFS, AND ECMWF SHOW H85 TEMPERATURES RANGING AROUND
THE LOWER TO MID 20S(C) TUESDAY AFTERNOON WITH THE WARMEST
TEMPERATURES IN EXTREME SOUTHWEST KANSAS. ALONG WITH PLENTY OF
SUNSHINE, WIDESPREAD 80S(F) ARE EXPECTED FOR HIGHS TUESDAY
AFTERNOON WITH NEAR 90F POSSIBLE IN SOME LOCATIONS IN SOUTHWEST
AND POSSIBLY SOUTH CENTRAL KANSAS. A SIGNIFICANT COOLING TREND
WILL THEN TAKE PLACE BY FRIDAY AS THE BROAD UPPER LEVEL TROUGH
PUSHES EAST THROUGH THE INTERMOUNTAIN WEST INTO THE WESTERN HIGH
PLAINS. AS MENTIONED EARLIER, AN ATTENDANT COLD FRONT TO THIS
SYSTEM IS EXPECTED TO PUSH INTO AND ACROSS WESTERN KANSAS BY LATE
FRIDAY ALLOWING MUCH COLDER AIR TO SURGE SOUTHWARD INTO THE
REGION. BELOW NORMAL TEMPERATURES ARE LIKELY BY THIS WEEKEND
AS A RESULT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1200 AM CDT MON OCT 22 2012
SOMEWHAT PROBLEMATIC 06Z TAFS AS THERE IS UNCERTAINTY IN HOW LOW CIGS
WILL BECOME ASSOCIATED WITH WRAP AROUND CLOUDS IN THE WAKE OF A WEAK
FRONT. THE HRRR IS SUGGESTING LIFR CIGS, HOWEVER, OBSERVATIONS ARE NOT
TRENDING THE MODEL OUT CURRENTLY SO AM A LITTLE DUBIOUS OF THIS SOLUTION.
HAVE TRENDED THE TAFS UPWARDS AND BROUGHT IN A LOW VFR CLOUD DECK THROUGH
THE OVERNIGHT HOURS. OTHERWISE, VFR CONDITIONS EXPECTED FOR THE REST
OF TODAY. WINDS WILL EVENTUALLY BECOME SOUTHERLY THIS AFTERNOON AS A
WARM FRONT MOVES NORTHWARD ACROSS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 46 78 53 86 / 0 0 0 0
GCK 43 76 50 85 / 0 0 0 0
EHA 47 80 52 87 / 0 0 0 0
LBL 46 80 51 87 / 0 0 0 0
HYS 47 75 52 84 / 0 10 0 0
P28 54 83 60 88 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...BURKE
LONG TERM...JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
331 AM CDT MON OCT 22 2012
.SHORT TERM...TODAY THROUGH TUESDAY...
LATEST WATER VAPOR IMAGERY SHOWS A LONG FETCH OF SOUTHWEST FLOW
ALOFT STRETCHING FROM THE EASTERN PACIFIC AND STREAMING INTO NORTH
DAKOTA. A LARGE AND POWERFUL UPPER LOW JUST SOUTH OF QUEEN CHARLOTTE
ISLANDS IS RESPONSIBLE FOR THIS LONG FETCH OF MOISTURE...AND WITH
SEVERAL JET STREAKS/SHORT WAVES ROTATING AROUND AND EJECTING THROUGH
THE UPPER TROUGH...SUPPORT FOR LARGE SCALE ASCENT WILL DOMINATE
MOST OF THE SHORT TERM PERIOD. TWO SHORTWAVES WILL IMPACT NORTH
DAKOTA THROUGH TUESDAY...THE FIRST SHORTWAVE IS SLIDING THROUGH
EASTERN MONTANA AND PRODUCING AN AREA OF RAIN SHOWERS IN
SOUTHEAST MONTANA/SOUTHWEST NORTH DAKOTA/AND NORTHWEST SOUTH
DAKOTA. SURFACE HIGH PRESSURE ALONG THE NORTHERN BORDER INTO
SOUTHERN MANITOBA SHOULD KEEP ENOUGH DRY AIR IN PLACE VIA A
NORTHEAST FLOW THROUGH MORNING HOURS...WHICH WILL INHIBIT
PRECIPITATION FROM REACHING THE GROUND. THE HRRR MODEL SEEMS TO BE
HANDLING THE CURRENT RADAR TRENDS WELL. EXPECT CEILINGS TO
GRADUALLY LOWER ACROSS CENTRAL NORTH DAKOTA WITH SCATTERED SHOWERS
DEVELOPING. THIS TREND WILL CONTINUE THROUGH THE DAY. THE HIGHEST
POPS/LIKELY CATEGORY WILL RESIDE IN THE NORTHWEST DURING THE
MORNING HOURS CLOSEST TO THE SHORTWAVE AND STRONGEST ASCENT. THE
RAP/NAM SOUNDINGS INDICATE A SHALLOW WARM LAYER OF AROUND OR LESS
THAN 1500FT EARLY THIS MORNING WHICH INDICATES THAT A RAIN/SNOW
MIX IS LIKELY IN THE WEST FOR A BRIEF PERIOD. SURFACE OBSERVATIONS
REVEAL THAT BEACH ALREADY HAD A MIX AND PROBABLY EXPERIENCED A
CHANGEOVER TO SNOW WITH A TEMPERATURE AT 34F. TEMPERATURES TODAY
WILL BE SIMILAR TO SUNDAY WITH HIGHS IN THE MID TO UPPER 40S NORTH
AND WEST...TO LOWER 50S FAR SOUTH CENTRAL.
THE SECOND SHORTWAVE IS ALREADY SLIDING INTO NORTHWEST CALIFORNIA
WITH LARGE SCALE ASCENT EVIDENT OVER OREGON AND IDAHO. THIS
SHORTWAVE WILL MOVE INTO MONTANA MONDAY NIGHT INDUCING A SURFACE
LOW PRESSURE AND FRONTAL SYSTEM OVER EASTERN MONTANA. THIS WILL
THEN SHIFT INTO CENTRAL AND NORTHERN NORTH DAKOTA TUESDAY.
ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS WILL COMMENCE
MONDAY NIGHT THROUGH TUESDAY. WITH THE TRACK OF THE SHORTWAVE AND
SURFACE LOW...H85 TEMPS WILL REMAIN ABOVE FREEZING IN ALL LOCATIONS
EXCEPT THE FAR NORTH WHERE A RAIN/SNOW MIX WILL OCCUR MONDAY
NIGHT. SHOWERS WILL TAPER OFF IN THE SOUTH TUESDAY BUT CONTINUE
THROUGH THE AFTERNOON IN THE NORTH. HIGHS TUESDAY WILL WARM TO
BETWEEN 60F AND 65F SOUTH CENTRAL AND THE JAMES RIVER VALLEY...BUT
REMAIN RATHER COOL IN THE NORTH WITH HIGHS REMAINING IN THE UPPER 40S.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY.
MODELS IN BETTER AGREEMENT WITH LARGE SCALE FEATURES IN EXTENDED
PERIOD...CONTINUING TO INDICATE AN ACTIVE WEEK AND SIGNIFICANT
COOL DOWN. TUESDAY NIGHT WILL SEE COLD FRONT DEPARTING EAST OF
STATE WITH A BAND OF PRECIP NUDGING INTO SOUTHEASTERN ND. COOLER
TEMPS ON WED WITH HIGHS IN THE 40S AND LOW POPS CONFINED TO
SOUTHERN AND EASTERN SECTIONS AS SURFACE HIGH PRESSURE TO THE
NORTHWEST PUSHES COLDER AIR ACROSS REGION. BY 00Z THU 850MB TEMPS
RANGE FROM 2C SOUTHEAST TO -6 NORTHWEST DROPPING TO AROUND -8C TO
-10C BY 00Z SAT. ECMWF SHOWS A LITTLE MORE PRECIP OVER THE
SOUTHEAST WED NIGHT COMPARED TO GFS AND GRIDS SHOW UP TO AN INCH
OF SNOW POSSIBLE OVER THIS AREA. OTHERWISE REMAINDER OF THE WEEK
REMAINS COLD AND MOSTLY DRY AS UPPER LEVEL LOW CENTER ROTATES
TOWARD HUDSON BAY WITH BROAD CYCLONIC FLOW OVER MOST OF NORTH
AMERICA. HIGH TEMPS FROM THU-SUN MAINLY IN THE 30S AND LOWS IN
TEENS AND 20S.
&&
.AVIATION...RAIN SHOWERS CONTINUE TO SPREAD FROM SOUTHWEST TO
NORTHEAST AND ARE CURRENTLY AFFECTING KDIK WITH LIGHT RAIN AND
CEILINGS NEAR 2000 FEET AT 08Z. EXPECT MVFR CONDITIONS AT TIMES OVER
KDIK AND KISN INTO THE AFTERNOON. A MIX WITH SNOW IS POSSIBLE OVER
WESTERN SITES EARLY THIS MORNING. VFR CONDITIONS EXPECTED OVER
KBIS...KMOT AND KJMS WITH BEST COVERAGE OF SHOWERS EXPECTED TO
REMAIN OVER WESTERN NORTH DAKOTA. ANOTHER SYSTEM APPROACHES LATER
TODAY BRINGING A CHANCE OF SHOWERS...LOWER CIGS AND MVFR CONDITIONS
TO ALL TAF SITES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM/AVIATION....JNS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1143 PM CDT SUN OCT 21 2012
.DISCUSSION...LATEST WATER VAPOR IMAGERY SHOWS A FAST MOVING
SHORTWAVE TROUGH/BAROCLINIC LEAF OVER SOUTHEAST MONTANA MOVING
NORTHEAST WITH TIME. A WEAK S-SHAPED APPEARANCE IS EVIDENT BUT
NOT EXPECTING IT TO DEVELOP MUCH FURTHER AS SIGNIFICANT 3HR
SURFACE PRESSURE FALLS ARE ABSENT...AS THE SPEED/POSITION OF THE
120KT H3 JET STREAK PEELS AWAY AND SHIFTS FURTHER NORTH AND EAST.
HOWEVER LARGE SCALE LIFT HAS AND CONTINUES TO INCREASE ACROSS
SOUTHEAST MONTANA/SOUTHWEST NORTH DAKOTA/AND NORTHWEST SOUTH
DAKOTA AS DENOTED BY THE INCREASED RADAR RETURNS. FULLY EXPECT THE
SOUTHWEST AND WESTERN ZONES TO FILL IN WITH PRECIPITATION AS
INDICATED BY THE CURRENT GRIDS/LIKELY POPS. THE NAM/RUC SOUNDINGS
SHOW A SHALLOW WARM LAYER ROM KDIK TO KISN AFTER 06Z. THE
WARM/MELTING LAYER IS GENERALLY AROUND OR SLIGHTLY LESS THAN 1500
FEET THICK WHICH WOULD INDICATE A RAIN/SNOW MIX. WILL CONTINUE TO
MONITOR THE SURFACE TEMPS AND WETBULB TEMPS...AS THE GRIDS DO
MENTION A SMALL RAIN/SNOW AREA IN THE WEST. THE HRRR PRECIPITATION
FIELD PICKS UP THE ENHANCING PRECIPITATION ECHOES IN SOUTH DAKOTA
AND DRIVES THEM INTO LINTON TO NEAR JAMESTOWN BY 12Z. BELIEVE
THIS LOOKS REASONABLE AND HAVE EXPANDED THE SLIGHT CHC FURTHER EAST.
&&
.AVIATION...CURRENTLY...RAIN SHOWERS ARE PROGRESSING INTO SOUTHWEST
NORTH DAKOTA. PRECIPITATION SHOULD BE TO KDIK BY THE 06 UTC TAF
ISSUANCE. WILL SPREAD RAIN NORTH AND EAST TO KISN AND KBIS BY AROUND
09 UTC...KJMS AROUND 10 UTC AND KMOT AFTER 12 UTC. DID PUT A MENTION
OF RAIN/SNOW MIX FOR A BRIEF PERIOD AROUND 12 UTC AT KISN. WILL
BRING MVFR-IFR CEILINGS INTO KDIK AROUND 09 UTC AND MVFR CEILINGS TO
KISN AROUND 11 UTC. AT THIS TIME WILL KEEP VFR CEILINGS FOR CENTRAL
TAF SITES WITH THIS INITIAL WAVE. MAINLY VFR CEILINGS DURING THE DAY
MONDAY...BUT SCATTERED MVFR CEILINGS CAN NOT BE RULED OUT. AFTER 00
UTC TUESDAY...LOW LEVEL MOISTURE INCREASES ACROSS WESTERN AND
CENTRAL NORTH DAKOTA AHEAD OF AN APPROACHING SURFACE LOW PRESSURE
SYSTEM. EXPECT MVFR CEILINGS AT ALL TAF SITES BY THE END OF THE
FORECAST PERIOD. SURFACE FLOW WILL REMAIN EASTERLY THROUGH THE
FORECAST PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...KS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
352 AM CDT MON OCT 22 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
351 AM CDT MON OCT 22 2012
AT 3 AM...A BAND OF SHOWERS AND THUNDERSTORMS WERE DEVELOPING
ALONG A WARM FRONT ACROSS SOUTHWEST IOWA AND NORTHERN MISSOURI.
THE LATEST RAP SHOWS THAT THERE IS STRONG 900 TO 800 MB
FRONTOGENESIS. IT SHOWS THAT AS THIS BAND MOVES NORTHEAST TOWARD
THE AREA THAT THIS FRONTOGENESIS GRADUALLY WEAKENS. IN
ADDITION...THESE STORMS WILL BE MOVING INTO AN AREA OF LESS
INSTABILITY. THEREFORE THINKING THAT THE THUNDERSTORMS WILL BECOME
MORE ISOLATED AS THEY MOVE THROUGH OUR AREA THIS MORNING AND EARLY
THIS AFTERNOON. WITH THE BEST MOISTURE TRANSPORT MAINLY OVER
NORTHERN ILLINOIS...THE HIGHEST PRECIPITATION PROBABILITIES SHOULD
BE LOCATED ACROSS NORTHEAST IOWA...AND SOUTHWEST AND CENTRAL
WISCONSIN. MANY OF THE MESO MODELS SUGGEST THAT THE CONVECTION
WILL EVOLVE INTO A LINE AS IT MOVES NORTHEAST THROUGH THE AREA. AS
A RESULT...TRIED TO TIME THE HIGHEST PRECIPITATION PROBABILITIES
TO ITS PARENT SHORT WAVE TROUGH. BUFKIT SOUNDINGS SHOW VERY SKINNY
CAPE ACROSS THE AREA...SO THE CHANCES OF ANY HAIL WITH ANY OF
THESE STORMS LOOKS RATHER MINUTE.
FOR TONIGHT...THE 22.00Z MODELS ARE IN FAIRLY GOOD AGREEMENT THAT
A WEAK LOW PRESSURE SYSTEM AND ITS WARM FRONT WILL APPROACH THE
AREA. THERE IS SOME WEAK TO MODERATE OMEGA AND ISENTROPIC LIFT
ASSOCIATED WITH THIS SYSTEM...SO EXPECT SOME LIGHT RAIN OR DRIZZLE
ACROSS THE AREA. THE SOUNDINGS SHOW THAT THERE WILL BE SOME
INSTABILITY ALOFT...BUT THERE IS SOME QUESTION WHETHER IT CAN BE
TAPPED. AS A RESULT...JUST LEFT ISOLATED THUNDERSTORMS IN THE FORECAST.
ON TUESDAY...THE MODELS SHOW THAT THE WARM FRONT WILL MOVE SLOWLY
NORTHEAST THROUGH THE AREA. THIS FRONT WILL USHER IN LOWER 60 DEW
POINTS AND TEMPERATURES IN THE 70S. IT WILL ALSO BE THE FOCUS FOR
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
ON TUESDAY NIGHT...BOTH THE NAM/WRF AND ECMWF SUGGEST THAT ANOTHER
SHORT WAVE TROUGH WILL MOVE NORTHEAST THROUGH THE AREA. DUE TO
THIS...KEPT A SLIGHT CHANCE OF PRECIPITATION IN THE FORECAST.
ON WEDNESDAY AFTERNOON AND EVENING...THE MODELS SHOW THAT A STRONG
COLD FRONT WILL MOVE EAST INTO THE FORECAST AREA. THE GEM AND
NAM/WRF ARE THE FASTEST AT MOVING THE COLD FRONT THROUGH THE AREA.
MEANWHILE THE ECMWF IS THE SLOWEST. THIS WILL GREATLY AFFECT THE
LOW TEMPERATURES ON WEDNESDAY NIGHT. IN ADDITION...WILL HAVE TO WATCH THIS
COLD FRONT FOR THE POSSIBILITY OF SEVERE WEATHER. THE NAM/WRF
SHOWS A LOW PRESSURE SYSTEM MOVING ALONG THIS FRONT WHICH HELPS
INCREASE THE LOW LEVEL SHEAR ACROSS THE AREA. THE 0-1 KM BULK SHEAR
EXCEEDS 25 KNOTS AND THE 0-1 KM HELICITY EXCEEDS 300 M2/S2 FROM
NORTH CENTRAL IOWA NORTHEAST INTO NORTHWEST WISCONSIN. THE ML
CAPES CLIMBS APPROACHES 2K. THIS HELPS THE SIGNIFICANT TORNADO
PARAMETER CLIMB TO 5. THE GFS ALSO SHOWS A POSSIBILITY OF
TORNADOES...BUT ITS VALUES ARE MUCH WEAKER. THE TORNADO
POSSIBILITIES WILL DEPEND A LOT ON WHETHER THE STORMS ARE ABLE TO
BECOME SURFACE BASED OR NOT. THE NAM/WRF WOULD SUGGEST THAT THEY
WILL BECOME SURFACE BASED DURING THE AFTERNOON. MEANWHILE THE GFS
WOULD SAY THAT THEY WILL REMAIN ELEVATED. FOR THE TIME
BEING...WILL JUST MENTION THE POSSIBILITY OF SEVERE WEATHER IN THE
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...THURSDAY THROUGH SUNDAY
351 AM CDT MON OCT 22 2012
ON THURSDAY...STRONG COLD AIR ADVECTION WILL MOVE INTO THE AREA.
AS THIS OCCURS...EXPECT THE TEMPERATURES TO FALL RAPIDLY INTO THE
40S BY THE AFTERNOON.
ON FRIDAY NIGHT...BOTH THE GFS AND ECMWF HAVE SHIFTED A LOW
PRESSURE SYSTEM FURTHER SOUTHEAST AWAY FROM THE AREA. MEANWHILE
THE GEM DEVELOPS A WAVE ALONG THE FRONT TO OUR SOUTHEAST AND THIS
BRINGS THE PRECIPITATION NORTHWEST INTO NORTHEAST IOWA AND
SOUTHWEST AND CENTRAL WISCONSIN. THIS IS IMPORTANT BECAUSE THE
TEMPERATURES ALOFT WILL BE COLD ENOUGH FOR SOME SNOW. FOR THE TIME
BEING...JUST WENT WITH THE SLIGHT CHANCES THAT WERE IN THE ALL BLEND.
&&
.AVIATION...THROUGH 06Z TUESDAY
1142 PM CDT SUN OCT 21 2012
SYSTEM FROM THE SOUTHWEST HAS BEEN SLOW TO MOVE TOWARD THE AREA
THIS EVENING WHICH HAS RESULTED IN A SLOWING TREND IN THE
FORECAST. THE STRATOCUMULUS HAS CONTINUED TO MOVE NORTH ACROSS IOWA
MOVING PAST THE I80 CORRIDOR. EXPECTING THIS TO CONTINUE TO PUSH
TOWARD THE AREA AND SPREAD ACROSS BOTH TAF SITES DURING THE
OVERNIGHT HOURS WITH VFR CEILINGS AND NO VISIBILITY RESTRICTIONS.
THE 22.00Z NAM CONTINUES TO SHOW THE BEST PV ADVECTION IN THE
500-300 MB LAYER MOVING BY TO THE SOUTH AS THE WEAK SHORT WAVE
TROUGH APPROACHES. THE ISENTROPIC UP GLIDE ON THE 300K SURFACE
WILL STILL OCCUR BUT IS SHOWN TO BE SLIGHTLY WEAKER AT 1-2 UBAR/S.
WITH SUCH WEAK FORCING NOT EXPECTING THE RAIN TO PRODUCE ANY
VISIBILITY RESTRICTIONS BUT CEILINGS SHOULD STILL COME DOWN TO
MVFR BUT NOT EXPECTING IFR AND REMOVED THIS FROM THE FORECAST. LOW
LEVELS WILL REMAIN SATURATED ONCE THE RAIN ENDS AND WITH A LITTLE
COOLING MONDAY EVENING COULD SEE SOME FOG DEVELOP WITH A GENERAL
LOWERING OF THE CEILINGS BUT REMAINING MVFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
313 AM CDT MON OCT 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1142 PM CDT SUN OCT 21 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
309 PM CDT SUN OCT 21 2012
PERIODIC CHANCES FOR SHOWERS AND THUNDERSTORMS EXPECTED INTO MID
WEEK WITH A WARM AND HUMID AIR MASS THAT WILL MOVE INTO THE REGION
OVERNIGHT.
CURRENTLY...A MID TO UPPER LEVEL RIDGE EXTENDS FROM THE GREAT
LAKES DOWN TO THE GULF COAST WITH BROAD MID LEVEL TROUGHING SLOWLY
PROPAGATING EAST ACROSS THE PACIFIC NORTHWEST AND SOUTHWESTERN
CANADA. A PREVIOUSLY CUT OFF MID LEVEL LOW OVER THE NORTHERN PART
OF BAJA CALIFORNIA HAS BEEN PICKED UP BY THE STRENGTHENING
SOUTHWEST FLOW WITH A SECONDARY MID LEVEL SHORTWAVE NOTED ON WATER
VAPOR AND RAP ANALYSIS ACROSS THE SOUTHERN PLAINS. THE FIRST WEAK
SHORTWAVE IN THE SOUTHERN PLAINS WILL MOVE INTO THE REGION THIS
EVENING AND BRING THE FIRST WAVE OF CLOUD COVER ALONG WITH IT.
LOW LEVEL MOISTURE TRANSPORT WILL RAPIDLY INCREASE OVERNIGHT AS
THE SECOND MID LEVEL SHORT WAVE LIFTS UP INTO THE REGION BETWEEN
6-12Z. ELEVATED INSTABILITY INCREASES AS THIS TRANSPORT KICKS IN
WITH 0-3KM SKINNY MUCAPE OF AROUND 500 J/KG GETTING INTO NORTHEAST
IOWA AND SOUTHWEST WISCONSIN BEFORE DAYBREAK. BASED ON THIS
INCREASING FORCING AND INSTABILITY...FELT CONFIDENT ENOUGH TO RAMP
UP THE PRECIPITATION CHANCES OVERNIGHT ON INTO TOMORROW. THE
SEVERE THREAT DOES NOT LOOK TOO HIGH WITH THE SKINNY CAPE AND
BETTER SHEAR FURTHER NORTH FROM THIS INSTABILITY AXIS THOUGH SOME
SMALL HAIL WILL BE POSSIBLE THOUGH OUT OF SOME OF THIS CONVECTION.
THE COLUMN SATURATES OUT REGION WIDE TOMORROW MORNING WITH THE
MOISTURE TRANSPORT SHIFTING EAST THROUGH THE DAY ALONG WITH THE
SHORTWAVE. AS PREVIOUSLY MENTIONED...CONFIDENCE HAS INCREASED
ENOUGH WITH THE 21.12Z NAM/GFS/GEM/ECMWF AND 21.09Z SREF ALL
SHOWING HIGH PROBABILITIES OF PRECIPITATION DEVELOPING ACROSS
THE AREA IN THE MORNING AND SHIFTING EAST IN THE AFTERNOON.
DESPITE THE LOW LEVEL WARM AIR ADVECTION...HAVE DECIDED TO SHAVE A
FEW DEGREES OFF OF HIGH TEMPERATURES TOMORROW WITH THE AMOUNT OF
CLOUD COVER AND RAIN THAT WILL BE AROUND THROUGH MUCH OF THE DAY.
SOME CLEARING COULD OCCUR IN THE AFTERNOON FROM THE SOUTHWEST AND
WILL PROBABLY BE WHEN WE HIT OUR HIGHS FOR THE DAY. WITH THE
BETTER SHEAR REMAINING OFF TO THE NORTH OF THE
FORCING/MOISTURE...IT DOES NOT APPEAR AS THOUGH THERE WILL BE ANY
WIDESPREAD SEVERE WEATHER THOUGH A FEW STORMS COULD STILL PRODUCE
SOME HAIL DURING THE DAY.
THE WARM FRONT WILL THEN STALL OUT ACROSS THE REGION TOMORROW
NIGHT THROUGH WEDNESDAY BEFORE THE NEXT SYSTEM MOVES ACROSS THE
NORTHERN PLAINS AND LIFTS THE FRONT TO THE NORTH. WITH THIS FRONT
LINGERING...THERE WILL REMAIN A CHANCE FOR SOME SHOWERS/STORMS
THROUGH MID WEEK THOUGH THERE DOES NOT APPEAR TO BE MUCH IN THE
WAY OF A FORCING TRIGGER. HAVE KEPT PRECIPITATION CHANCES ON THE
LOW SIDE GOING INTO MID WEEK AS A RESULT. TEMPERATURES AND
HUMIDITY WILL BE ABOVE NORMAL WITH DEW POINTS LINGERING AROUND 60
ACROSS THE FORECAST AREA AND TEMPERATURES IN THE 70S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
309 PM CDT SUN OCT 21 2012
PATTERN CHANGE COMING LATER THIS WEEK AFTER A COLD FRONT COMES
THROUGH AND THE SOUTHWESTERLY FLOW ALOFT GOES WEST TO NORTHWEST.
A BROAD MID TO UPPER LEVEL TROUGH WILL SLOWLY PROPAGATE ACROSS THE
NORTHERN PLAINS AND INTO THE GREAT LAKES FROM MID WEEK INTO NEXT
WEEKEND WITH AM EMBEDDED MID LEVEL TROUGH THAT DEVELOPS ALONG THE
SOUTHEASTERN PERIPHERY OF IT WEDNESDAY NIGHT INTO THURSDAY. THE
GFS HAS BEEN THE MOST CONSISTENT WITH THIS SYSTEM AND THE COLD
FRONT PASSAGE WITH THE ECMWF AND GEM COMING AROUND TO ITS TREND
OVER THE PAST FEW RUNS. THIS SOLUTION IS A LESS AMPLIFIED TO WHAT
THE 21.12Z ECMWF OFFERS UP WITH A POSITIVELY TILTED MID LEVEL
TROUGH SWINGING THROUGH. THE 21.12Z GFS/GEM BRING THIS COLD FRONT
INTO THE REGION WEDNESDAY NIGHT AND HAVE IT INTO THE WESTERN GREAT
LAKES BY THURSDAY AFTERNOON.
AFTER THE FRONT COMES THROUGH...NORTHWESTERLY FLOW WILL USHER IN
MUCH COLDER AIR IN FROM CANADA WITH 850MB TEMPERATURES DROPPING
DOWN TO AROUND -7C WITH HIGH TEMPERATURES STUCK IN THE 40S BY NEXT
WEEKEND. ANOTHER SYSTEM TRACKS ALONG THE COLD FRONT ON FRIDAY BUT
EACH FORM OF 21.12Z GUIDANCE HAS A DIFFERING SOLUTION WITH HOW FAR
NORTHWEST THE PRECIPITATION MAKES IT. WITH THE GFS BEING THE MOST
CONSISTENT OVER THE PAST FEW DAYS...HAVE OPTED TO GO ALONG WITH IT
AND ITS TIMING. 21.12Z GFS BUFKIT SOUNDINGS SHOW THAT IT COULD BE
COLD ENOUGH TO CHANGE THE PRECIPITATION TYPE OVER TO SNOW
BRIEFLY...SO HAVE INTRODUCED A MIX OF RAIN AND SNOW SHOWERS EARLY
SATURDAY MORNING.
&&
.AVIATION...THROUGH 06Z TUESDAY
1142 PM CDT SUN OCT 21 2012
SYSTEM FROM THE SOUTHWEST HAS BEEN SLOW TO MOVE TOWARD THE AREA
THIS EVENING WHICH HAS RESULTED IN A SLOWING TREND IN THE
FORECAST. THE STRATOCUMULUS HAS CONTINUED TO MOVE NORTH ACROSS IOWA
MOVING PAST THE I80 CORRIDOR. EXPECTING THIS TO CONTINUE TO PUSH
TOWARD THE AREA AND SPREAD ACROSS BOTH TAF SITES DURING THE
OVERNIGHT HOURS WITH VFR CEILINGS AND NO VISIBILITY RESTRICTIONS.
THE 22.00Z NAM CONTINUES TO SHOW THE BEST PV ADVECTION IN THE
500-300 MB LAYER MOVING BY TO THE SOUTH AS THE WEAK SHORT WAVE
TROUGH APPROACHES. THE ISENTROPIC UP GLIDE ON THE 300K SURFACE
WILL STILL OCCUR BUT IS SHOWN TO BE SLIGHTLY WEAKER AT 1-2 UBAR/S.
WITH SUCH WEAK FORCING NOT EXPECTING THE RAIN TO PRODUCE ANY
VISIBILITY RESTRICTIONS BUT CEILINGS SHOULD STILL COME DOWN TO
MVFR BUT NOT EXPECTING IFR AND REMOVED THIS FROM THE FORECAST. LOW
LEVELS WILL REMAIN SATURATED ONCE THE RAIN ENDS AND WITH A LITTLE
COOLING MONDAY EVENING COULD SEE SOME FOG DEVELOP WITH A GENERAL
LOWERING OF THE CEILINGS BUT REMAINING MVFR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
309 PM CDT SUN OCT 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...04
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
850 AM PDT MON OCT 22 2012
.DISCUSSION...
COLD FRONT LOCATED FROM ABOUT BUTTE MEADOWS-CHICO-CAPAY-VALLEJO THIS
MORNING MOVING SEWD ABOUT 20 KTS. BROAD AREA OF PRE-FRONTAL PCPN
EXTENDS AHEAD OF THE FRONT WITH MODERATE TO HEAVY AREAS/POCKETS OF
HEAVIER PRECIP. DUAL POL DATA SUGGEST WET SNOW DOWN TO AROUND 4 KFT
OVER W SLOPE SIERNEV THIS MORNING. THE HRRR MODEL INDICATES THE
PRECIP WILL BE TAPERING IN INTENSITY OVER THE SIERRA WITH ISOLATED
SHOWERS IN THE VALLEY DURING THE AFTERNOON. DARKENING/SUBSIDENCE IN
THE WATER VAPOR IMAGERY MOVING ONSHORE INDICATES THE END OF THE MAIN
PRE-FRONTAL PRECIP...BUT SAT IMAGERY ALSO SHOWS COLD UNSTABLE AIR
WITH ISOLD THUNDER JUST OFF THE COAST WILL BE ROTATING INLAND THIS
AFTERNOON BEHIND THIS AREA OF SUBSIDENCE. THE HRRR PICKS UP THE
PRECIP OVER THE COASTAL RANGE AND WRN SAC VLY THIS AFTERNOON...WITH
UPSLOPE FLOW CONTINUING PRECIP OVER THE HIGH SIERRA. WHILE THE NAM
HIGHLIGHTS THE COASTAL RANGE AND W SIDE OF THE SAC VLY FOR THE
GREATEST INSTABILITY THIS AFTERNOON...THE HRRR HIGHLIGHTS THE NRN
SAC VLY AND NE SAC VLY FOOTHILLS.
RAINFALL AMOUNTS ARE NEARING/EXCEEDING AN INCH OVER SOME PARTS OF
THE VALLEY AND SNOWFALL AROUND 6 TO 12 INCHES ABOVE 5500 FEET IN THE
NORTHERN SIERRA ARE EXPECTED....THOUGH A FEW HIGHER ELEVATION SPOTS
MAY SEE A COUPLE OF FEET.
A MINUS 3 TO 4 STANDARD DEVIATION 500 MBS HEIGHT ANOMALY WILL BE
AFFECTING NORCAL THROUGH WED. PRECIP CHANCES WILL ALSO CONTINUE AS
DISTURBANCES/VORT MAXES MOVE THROUGH THE LARGE UPPER TROUGH. DRIER
AND MILDER WEATHER EXPECTED TO RETURN LATER IN THE WEEK AS RIDGING
FROM THE EPAC SHIFTS OVERHEAD. JHM
&&
.AVIATION...
COLDFRONT IMPACTING NORCAL TODAY. TAF SITES WILL OSCILLATE BTWN
VFR-MVFR VSBYS...BRIEF PERIODS OF MVFR CIGS DURING HEAVIER RAIN.
SLY WINDS THRU THE VLY TODAY AROUND 10-25 KTS. OVER SIERRA...
MVFR/IFR CONDS WITH SNOW LEVELS AROUND 5000 FT AND SLY TO SWLY
WINDS AROUND 20-35 KTS WITH GUSTS UP TO 50 KTS...LCLLY HIGHER
GUSTS OVER SIERRA RIDGETOPS. FOR COASTAL MTNS...SNOW LEVEL BTWN
5000-6000 FT WITH VFR/MVFR CONDS AND W TO SW WINDS 10-20 KTS WITH
GUSTS AROUND 25 KTS. JBB
&&
.STO WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 AM PDT TUESDAY ABOVE 5500 FEET FOR
THE WEST SLOPE NORTHERN SIERRA NEVADA...WESTERN PLUMAS
COUNTY/LASSEN PARK.
WINTER WEATHER ADVISORY UNTIL 5 PM PDT THIS AFTERNOON ABOVE 5000
FEET FOR THE MOUNTAINS SOUTHWESTERN SHASTA COUNTY TO NORTHERN
LAKE COUNTY.
WINTER WEATHER ADVISORY UNTIL 5 PM PDT THIS AFTERNOON ABOVE 3500
FEET FOR THE BURNEY BASIN / EASTERN SHASTA COUNTY...SHASTA LAKE
AREA / NORTHERN SHASTA COUNTY.
&&
$$
AREA FORECAST DISCUSSION
NWS TAUNTON MA
647 AM EDT MON OCT 22 2012
.SYNOPSIS...
DRY AND SEASONABLE WEATHER IS EXPECTED TO CONTINUE THROUGH TUESDAY
AFTERNOON. A WEAK WARM FRONT COULD BRING A PERIOD OF LIGHT RAIN
FROM LATE TUE INTO WED NIGHT. THEREAFTER CANADIAN HIGH PRESSURE
DELIVERS DRY AND SEASONABLE WEATHER THU AND FRI. A BRIEF WARM UP
MAY OCCUR SAT BEFORE WET AND WINDY WEATHER POSSIBLY MOVES UP THE
EASTERN SEABOARD SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7 AM UPDATE...
ONLY CHANGE TO PREVIOUS FORECAST WAS TO SLIGHTLY MODIFY OUR SKY
GRIDS TO BETTER REFLECT LATEST SATELLITE TRENDS...WHICH INDICATE
SOME HIGH BASED SC IN THE NW FLOW ALOFT MOVING ACROSS THE AREA.
CLOUDS ARE FAIRLY PATCHY AND THIN SO EXPECTING AT LEAST PARTIAL
SUNSHINE THIS MORNING. OTHERWISE PREVIOUS FORECAST MATCHING UP
WELL WITH LATEST OBSERVATIONS. PREVIOUS DISCUSSION BELOW.
====================================================================
WV IMG COMBINED WITH CURRENT RAP DATA SUGGESTS SHEARED VORT MAX IS
JUST NOW MAKING ITS WAY INTO NW PORTIONS OF THE FA THIS MORNING.
THE COMBINATION OF THIS WAVE AN H85 LLJ OF ABOUT 40 KT AND STRONG
CAA FROM AN EXITING CUTOFF HAVE GENERATED A FAIR AMOUNT OF SC
OVERNIGHT...AND KEPT A 5-12KT WIND. GIVEN THIS FACT...MODELS
STRUGGLE WITH TEMPS/DWPTS AND ARE GENERALLY TOO LOW ACROSS THE
BOARD. HAVE ADJUSTED TEMPS/DWPTS CLOSER TO THE HIGHER BC GRIDS FOR
THE REMAINING OVERNIGHT TEMPS AND THE HIGHS TODAY. THIS LED TO
ANOTHER DAY OF TEMPS IN THE LOWER 60S ACROSS THE AREA...WHICH IS
GENERALLY SEASONABLE FOR THIS TIME OF YEAR.
OTHERWISE...THE WEAK VORT MAX WILL ALLOW FOR A WEAK SFC WAVE TO
TIGHTEN THE SFC PRES GRADIENT IN ADVANCE OF THE HIGH PRES BUILDING
OVER FROM THE SW. WHILE THE LLJ IS 40+ KT IN THE EARLY MORNING
HOURS THIS MORNING...THE COMBINATION OF LACKING DIURNAL MIXING AND
A FAIRLY ROBUST SUBSIDENCE INVERSION WILL KEEP BL FROM TAPPING
THIS LEVEL. HOWEVER...SHOULD STILL SEE A BIT STRONGER W TO NW
GUSTS TODAY THAN YESTERDAY WITH SOME 30 MPH POSSIBLE. THESE
BLUSTERY CONDITIONS WILL MAKE THINGS SEEM A BIT COOLER THAN
NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
HIGH PRES BEGINS TO CREST OVER THE REGION AS WEAK H5 RIDGE MOVES
IN BEHIND THE EXITING VORT MAX. THIS SHOULD ALLOW SKIES TO CLEAR
AND WINDS TO DECOUPLE OVERNIGHT. THEREFORE...DRY CONDITIONS
PREVAIL AND MIN TEMPS COOLER THAN SUN NIGHT. UPPER 30S NW WITH
LOWER 40S TOWARD THE SE.
TUE...
EXPECTING CLOUDS TO GRADUALLY INCREASE FROM THE SW AS A SLOWING
WARM FRONT APPROACHES. NOT EXPECTING THE FRONT ITSELF TO MAKE IT
INTO SRN NEW ENGLAND AS IT ENCOUNTERS BLOCKING FLOW PATTERN TO THE
NE AND BECOMES PARALLEL WITH MID AND UPPER LVL FLOW.
HOWEVER...GUIDANCE SOUNDINGS SUPPORT SOME MOISTURE LOADING OF THE
COLUMN AND GIVEN SOME WEAK OVERRUNNING FLOW AND F-GEN...MAY SEE
THE DEVELOPMENT OF SCATTERED SHOWERS BY LATE DAY...PARTICULARLY TO
THE W AND S. NOT EXPECTING A WASHOUT...AS SOUNDINGS TAKE SOME TIME
TO MOISTEN AND FORCING IS RELATIVELY WEAK. HIGHS WILL BE SIMILAR
TO PREVIOUS DAYS GIVEN LITTLE CHANGE IN AIRMASS AND LOW LVL COOL
AIR SHOULD KEEP WARM FRONT AT BAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* LIGHT RAIN POSSIBLE TUE NIGHT THRU WED NGT...OTHERWISE DRY WX
* SEASONABLE TEMPERATURES MUCH OF THE WORK WEEK
* RAIN AND WIND POSSIBLE LATE NEXT WEEKEND INTO EARLY NXT WK
TUE NIGHT THROUGH FRI...
00Z MODELS IN VERY GOOD AGREEMENT ON LONG WAVE TROUGH PERSISTING
OVER NEWFOUNDLAND MUCH OF THIS WEEK. THIS PRECLUDES WARM AIRMASS
OVER THE GREAT LAKES AND MID ATLC REGION FROM ADVECTING NORTHEAST
INTO NEW ENGLAND. THE WARM AIR DOES MAKES A RUN AT NEW ENGLAND TUE
NIGHT INTO WED NIGHT AS SURFACE WAVE RIDES THE BOUNDARY INTO THE
REGION. THUS A PERIOD OF LIGHT RAIN IS POSSIBLE DURING THIS TIME.
DESPITE LIKELY POPS FROM THE GMOS...WE PREFERRED TO CAP POPS AT HIGH
CHANCE GIVEN QPF APPEARS LIGHT AND THERE MAY BE SUFFICIENT DRY AIR
OVER THE AREA TO ERODE SOME OF THE PRECIP. WED WILL LIKELY BE THE
COOLEST DAY OF THE WEEK...ESP IF RAIN MATERIALIZES.
GIVEN THE DEVELOPING BLOCK PATTERN THE WARM FRONT REMAINS SOUTH OF
THE AREA WITH CANADIAN HIGH PRES SETTLING OVER NEW ENGLAND THU INTO
FRI. THUS SHALLOW COOL AIR SHOULD WIN OUT OVER THE AREA MUCH OF THE
WEEK. HOWEVER THIS STILL YIELDS TEMPERATURES NEAR NORMAL WITH HIGHS
IN THE 60S. IN FACT IT WILL FEEL QUITE PLEASANT FOR LATE OCT WITH AT
LEAST PARTIAL SUNSHINE AND LIGHT WINDS.
SAT/SUN...
A PIECE OF THE WARM AIRMASS OVER THE GREAT LAKES AND OH VLY MAY
ADVECT INTO THE REGION FRI OR SAT AS MID LEVEL RIDGE BRIEFLY SLIDES
ACROSS NEW ENGLAND. THIS SHOULD CONTINUE DRY WEATHER FROM FRI INTO
SAT. THEREAFTER THE DRAMA BUILDS AS TELECONNECTIONS/ENSEMBLES AND
DETERMINISTIC MODEL RUNS ALL SUPPORT A PATTERN/FLOW REGIME CHANGE AS
THE NAO AND AO BECOMING INCREASINGLY NEGATIVE LATE NEXT WEEKEND INTO
EARLY NEXT WEEK. TO INCREASE THE COMPLEXITY OF THE PATTERN CHANGE
IS THE LIKELIHOOD /TPC EST 80% CHC OF DVLPMNT/ OF A TROPICAL CYCLONE
/TS SANDY/ EMERGING FROM THE CARIBBEAN TO THE NEAR THE SOUTHEAST
STATES OF THE U.S. THE ECMWF/ECENS AND TO A LESSER EXTENT THE UKMET
HAVE A PHASED SOLUTION...WITH THE AMPLIFIED POLAR JET CAPTURING THE
TROPICAL CYCLONE OFF THE SOUTHEAST COAST FORMING A HYBRID SYSTEM
INTO THE MID ATLC AND NORTHEAST SUN/MON.
THE NEW GFS OFFERS AN UNPHASED SOLUTION...HAVING THE POLAR JET
KICKING THE TROPICAL CYCLONE OUT TO SEA WITHOUT MUCH FANFARE FOR THE
NORTHEAST. AT THIS TIME RANGE WE MUST EXPECT THE DETERMINISTIC
MODELS TO WAVER BACK AND FORTH BETWEEN PHASED AND UNPHASED SOLUTIONS
FOR THE REMAINDER OF THE UPCOMING WEEK. THE INTERACTION BETWEEN THE
POLAR JET /ITS AMPLITUDE AND TILT/ AND POTENTIAL TROPICAL CYCLONE IS
VERY COMPLEX AND OFFERS LOW PREDICTABILITY AT THIS TIME RANGE. THUS
MODELS WILL UNLIKELY RESOLVE THESE COMPLEX INTERACTIONS UNTIL
SOMETIME FRI OR SAT. SO WILL MAINTAIN CHANCE POPS SUN TO ADDRESS
THIS UNCERTAINTY AND INCLUDE SOME WORDING IN THE HWO TO HIGHLIGHT A
LOW RISK OF SIGNIFICANT PRECIP AND STRONG WINDS WITH HYBRID LOW
ALONG OR NEAR THE EAST COAST.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
7 AM UPDATE...
NO CHANGE FROM PREVIOUS FORECAST...HIGH CONFIDENCE FOR VFR
CONDITIONS ALONG WITH GUSTY WEST WINDS DURING THE DAYLIGHT HOURS.
OVERVIEW...HIGH CONFIDENCE.
VFR. W TO NW WINDS WITH GUSTS 20-30 KT FROM MID MORNING THROUGH
THE AFTERNOON. WINDS DIMINISH DURING THE EVENING.
KBOS TAF...HIGH CONFIDENCE IN TAF.
VFR. W TO NW WINDS GUST 20-30 KT MID MORNING INTO THE
AFTERNOON...WEAKENING IN THE EVENING.
KBDL TAF...HIGH CONFIDENCE IN TAF.
VFR. W TO NW WINDS GUST 20-30 KT MID MORNING INTO THE
AFTERNOON...WEAKENING IN THE EVENING.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE TO HIGH CONFIDENCE FOR A PERIOD OF MVFR IN LIGHT RAIN TUE
NGT THRU WED NGT. LOW RISK OF IFR DURING THIS TIME. IMPROVING
CONDITIONS THU AND FRI...LIKELY TO VFR BUT CAN/T RULE OUT MVFR CIGS
AT TIMES.
&&
.MARINE...
HIGH CONFIDENCE.
W TO NW WINDS TODAY WITH GUSTS OF 20-30 KT OVER ALL WATERS.
THEREFORE...SMALL CRAFT ADVISORIES STAND INTO THE EVENING FOR NEAR
SHORE WATERS...AND INTO THE OVERNIGHT FOR OUTER WATERS AS SEAS OF
5-6 FT MAY TAKE SOME TIME TO DIMINISH ON THE OUTER WATERS.
HIGH PRES BUILDS OVER THE WATERS LATE TONIGHT INTO TUE...WHICH
WILL ALLOW WINDS/SEAS TO SUBSIDE AND QUIET BOATING WX TO RETURN.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
MODERATE TO HIGH CONFIDENCE FOR QUIET WEATHER WITH HIGH PRES OVER
THE NORTHEAST. A WARM FRONT APPROACHES NEW ENGLAND TUE NGT THRU WED
NGT YIELDING PERIODS OF LIGHT RAIN AND REDUCED VSBY. HOWEVER WARM
FRONT SLIDES SOUTH OF NEW ENGLAND THU AND FRI WITH HIGH PRES
REINSERTING ITSELF OVER THE NORTHEAST. THUS NO SIGNIFICANT WIND OR
SEAS THIS PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ230-
235>237-251.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ254>256.
&&
$$
SYNOPSIS...NOCERA/DOODY
NEAR TERM...NOCERA/DOODY
SHORT TERM...DOODY
LONG TERM...NOCERA
AVIATION...NOCERA/DOODY
MARINE...NOCERA/DOODY
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
606 AM CDT MON OCT 22 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 1100 PM CDT SUN OCT 21 2012
THE 22.00Z 250 HPA RAOB MAP SHOWED JET LEVEL WINDS AROUND 100 KT ACROSS
THE NORTHERN PORTION OF THE COUNTRY. A SOUTHWESTERLY JET WAS OBSERVED
FROM THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS. DOWNSTREAM, THIS
FLOW TURNED NORTHWESTERLY ACROSS THE GREAT LAKES. AT 500 HPA, A LARGE
TROF WAS LOCATED JUST WEST OF BRITISH COLUMBIA. ANOTHER TROF WAS FOUND
ACROSS NORTHERN SASKATCHEWAN. VERY COLD MID LEVEL TEMPERATURES AROUND
-33 TO -36 DEG C WERE ASSOCIATED WITH THESE TWO DISTURBANCES. SOME MID
LEVEL MOISTURE WAS NOTED ACROSS THE CENTRAL AND NORTHERN ROCKIES. THERE
WAS AN OPEN TROF MOVING NORTHEAST ACROSS THE DESERT SW/SONORA. SHORTWAVE
RIDGING WAS LOCATED ACROSS THE MIDWEST/LOWER MISSISSIPPI RIVER VALLEY.
AT 700 AND 850 HPA, THE WARM PLUME STILL PREVAILED ACROSS THE CENTRAL
AND SOUTHERN PLAINS. SOME LOW LEVEL MOISTURE ADVECTION WAS OBSERVED
ACROSS OKLAHOMA/EASTERN KANSAS. A DOWNSLOPE WARM AND DRY PLUME WAS VERY
OBVIOUS PER THE KDDC RAOB. AT THE SFC, A COLD FRONT EXTENDED FROM MINNESOTA
TO WESTERN KANSAS. DEWPOINTS WERE RUNNING IN THE 60S DEG F AHEAD OF
THIS BOUNDARY FROM TEXAS TO IOWA.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 321 AM CDT MON OCT 22 2012
COMPLICATED FORECAST TODAY WITH HIGH TEMPERATURE BUST POTENTIAL,
PARTICULARLY ALONG INTERSTATE 70. LOW STRATUS IS BEGINNING TO INCREASE
IN AERIAL COVERAGE PER THE 11U-3.9U SATELLITE CHANNEL AND KHYS IS ALREADY
IN THE LOW STRATUS/IFR CONDITIONS. FOR THE TEMPERATURE FORECAST, WILL
PUT MORE OF AN EMPHASIS ON THE 00Z NAM/ARW-NMM MESOSCALE MODELS WHICH
KEEPS CENTRAL KANSAS UNDER STRATUS AND RESULTANT COOLER TEMPERATURES.
THE ARW-NMM IS VERY AGGRESSIVE WITH COOLER TEMPERATURES AND KEEPS KHYS
IN THE 50S DEG F. THE NAM SUGGESTS MID 60S DEG F. WILL COMPROMISE BETWEEN
THE PREVIOUS FORECAST AND THE NEW 00Z DATA AND KEEP TEMPERATURES AROUND
70 DEG F ACROSS WEST CENTRAL AND CENTRAL KANSAS. THERE IS LARGE UNCERTAINTY
ON HOW LONG THE STRATUS WILL STICK AROUND AS ISENTROPIC DOWNGLIDE IS
EVENTUALLY FORECAST. WILL ALSO KEEP PATCHY FOG IN THE WX GRIDS GENERALLY
EAST OF HIGHWAY 283 THIS MORNING. HRRR SUGGESTS DENSE FOG THIS MORNING
BUT WILL GO WITH PATCHY FOR NOW AS CURRENT OBSERVATIONS SHOW THAT THE
HRRR MODEL IS BEING A BIT AGGRESSIVE ON FORECAST VISIBILITIES FOR THE
CURRENT HOUR. THERE ALSO COULD BE SOME DRIZZLE ALONG I-70 BUT NOT SURE
OF THE SATURATED LAYER WILL BE THICK ENOUGH AS BUFR SOUNDINGS ARE AROUND
2000 FEET INSTEAD OF THE 3000 FEET IDEAL THICKNESS. THE WARMEST TEMPERATURES
ARE EXPECTED ALONG THE FRONTAL BOUNDARY ACROSS SOUTH CENTRAL KANSAS
WHERE 80S DEG ARE LIKELY AS A NARROW WEDGE OF WARMER 850 HPA TEMPERATURES
/DOWNSLOPE WINDS ARE FORECAST.
BY THIS EVENING, THE AFOREMENTIONED BOUNDARY WILL RETURN NORTHWARD AS
A WARM FRONT. WILL GO WITH WARMER MINIMUM TEMPERATURES ACROSS SOUTH
CENTRAL KANSAS AS FAIRLY HIGH SURFACE DEWPOINTS ADVECT NORTHWARD AGAIN.
PATCHY FOG LOOKS POSSIBLE AGAIN TOMORROW MORNING VIA BUFR SOUNDINGS
/MOS GUIDANCE/ AND BOUNDARY LAYER RELATIVE HUMIDITY PROGS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 AM CDT MON OCT 22 2012
MAIN CONCERNS IN THIS PERIOD ARE FIRE WEATHER CONDITIONS FOR TUESDAY
AND WEDNESDAY AFTERNOONS IN THE SOUTHWEST FA FROM NESS CITY TO DODGE
CITY AND WEST, CHANCES OF THUNDERSTORMS IN THE EAST FA FROM HAYS TO
COLDWATER AND EAST WITH A COLD FRONT FOR WEDNESDAY NIGHT INTO
THURSDAY MORNING, AND THE POSSIBILITY FOR BELOW FREEZING
TEMPERATURES FOR NEXT SATURDAY AND SUNDAY MORNINGS.
FOR TUESDAY AND WEDNESDAY SOUTHWEST AND SOUTH CENTRAL KANSAS WILL BE
IN THE WARM SECTOR AHEAD OF A STRONG UPPER LEVEL BROAD TROUGH MOVING
FROM THE WESTERN CONUS AND INTO THE ROCKIES AND 4 CORNERS REGION. A
DRYLINE IS FORECAST TO SET UP FROM WAKEENEY TO DODGE CITY AND MEADE,
THEN PROGRESS EASTWARD DURING THE AFTERNOON. THE SAME SITUATION
REPEATS ITSELF ON WEDNESDAY AFTERNOON. SURFACE LOW PRESSURE IN THE
LEE OF THE ROCKIES WILL DEEPEN INTO WEDNESDAY WITH THE STRONGEST
PRESSURE GRADIENT ON WEDNESDAY AFTERNOON. BY TUESDAY AFTERNOON THE
SOUTH TO SOUTHWEST WINDS COULD BE FROM 15 TO 25 MPH AND THEN 20 TO
30 MPH ON WEDNESDAY AFTERNOON. RELATIVE HUMIDITIES SHOULD FALL BELOW
15 TO 20 PERCENT BOTH AFTERNOONS, SO WILL HAVE TO KEEP A CLOSE EYE
OUT FOR A FIRE WEATHER WATCH ESPECIALLY FOR WEDNESDAY AFTERNOON FOR
OUR SOUTHWESTERN COUNTIES. SINCE TUESDAY AFTERNOON WINDS ARE NOT AS
STRONG WILL NOT GO WITH A WATCH AT THIS TIME. AFTERNOON HIGHS SHOULD
BE IN THE MID TO UPPER 80S FOR BOTH DAYS. OVERNIGHT LOWS ARE
FORECAST TO BE VERY MILD ON TUESDAY NIGHT WITH SOUTH BREEZES AT 10
TO 20 MPH.
THEN FOR WEDNESDAY NIGHT AND THURSDAY THE BROAD UPPER LEVEL TROUGH
MOVES ACROSS THE PLAINS PUSHING A STRONG COLD FRONT ACROSS WESTERN
KANSAS. WITH GOOD MOISTURE AHEAD OF THE COLD FRONT A FEW STRONG TO
POSSIBLY SEVERE THUNDERSTORMS MAY DEVELOP ALONG AND AHEAD OF THE
COLD FRONT. THERE WILL BE PLENTY OF LAYER WIND SHEAR WITH FORECAST
CAPE AROUND 1000 J/KG. THE AREA FROM HAYS SOUTH TO GREENSBURG AND
COLDWATER AND EAST HAS THE BEST CHANCES FOR THUNDERSTORMS INTO LATE
WEDNESDAY NIGHT. NORTH WINDS OF 15 TO 25 MPH AND GUSTY WILL FOLLOW
THE FRONT THAT SHOULD BE MOVING LASTLY THROUGH MEDICINE LODGE BY 7
AM THURSDAY MORNING. THURSDAY MORNING LOWS ARE FORECAST TO RANGE
FROM THE MID 40S WEST TO THE MID 50S EAST FROM SAINT JOHN TO
MEDICINE LODGE. DAYTIME HIGHS ON THURSDAY WILL ONLY BE IN THE MID TO
UPPER 50S NORTH TO MID 60S SOUTH AS MUCH COLDER SURFACE HIGH
PRESSURE FOLLOWS THE COLD FRONT. THURSDAY NIGHT LOWS LOOK TO BE IN
THE MID TO UPPER 30S WITH SOME MIXING.
FOR FRIDAY A SECONDARY UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE
PLAINS WITH MAINLY MID AND HIGH LEVEL CLOUDINESS. THE GFS LOOKS WAY
OVER SATURATED AND IS A TYPICAL MODEL BIAS WHILE THE NEW ECMWF LOOK
VERY DRY THROUGH THE LAYER. WILL GO AHEAD AND HEDGE TOWARD THE ECMWF
AND TAKE POPS DOWN TO SILENT. A STRONG RIDGE OF SURFACE HIGH
PRESSURE WILL REINFORCE ITSELF INTO THE WESTERN HIGH PLAINS WITH
HIGHS ONLY IN THE UPPER 40S TO LOWER 50S.
FOR THE WEEKEND A VERY DRY AIRMASS IS FORECAST WITH DEWPOINTS IN THE
20`S. DAYTIME HIGHS FOR SATURDAY ARE AGAIN ONLY IN THE UPPER 40S TO
LOWER 50S THEN WARM INTO THE 50S ON SUNDAY. BY SATURDAY MORNING THE
MODELS ARE FORECASTING A SHARP RIDGE AXIS OF HIGH PRESSURE WITH
LIGHT WINDS AND CLEAR SKIES. ON SUNDAY MORNING THE GFS HAS THE RIDGE
MOVING EAST INTO CENTRAL KANSAS WHILE THE ECMWF HAS IT AGAIN OVER
SOUTHWEST KANSAS. IF THE MODELS ARE CORRECT THERE IS A GOOD
POSSIBILITY OF A FREEZE OR KILLING FREEZE ON BOTH EARLY MORNINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 559 AM CDT MON OCT 22 2012
A COLD FRONT WILL CONTINUE TO MOVE ACROSS WESTERN KANSAS TODAY
WITH LIGHT NORTH TO NORTHWEST WINDS. SOME IFR CONDITIONS ARE
FORECAST WITH LOW STRATUS AND FOG THROUGH 14Z AT KDDC AND KGCK AND
AND MAINLY LOW CIGS THROUGH 06Z AT KHYS. AN UPPER LEVEL SHORTWAVE
TROUGH WILL THEN BRING SOME MID AND HIGH CLOUDINESS THROUGH MID TO
LATE AFTERNOON, THEN LOOK FOR CLEARING SKIES. AS LOW PRESSURE
DEEPENS IN EASTERN COLORADO TONIGHT, LIGHT EAST TO SOUTHEASTERLY
WINDS BECOME SOUTH TO SOUTHWEST WITH A RETURNING WARM FROM AFTER
06Z TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 75 52 87 60 / 0 0 0 0
GCK 74 47 87 56 / 0 0 0 0
EHA 78 50 87 57 / 0 0 0 0
LBL 79 48 88 55 / 0 0 0 0
HYS 69 52 85 56 / 0 0 0 0
P28 84 61 90 65 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1041 AM CDT MON OCT 22 2012
.UPDATE...
A COMPLEX OF SHOWERS AND THUNDERSTORMS CONTINUES TO PUSH EASTWARD
INTO YOUNG...JACK AND STEPHENS COUNTY LATE THIS MORNING. THE CAPPING
INVERSION EVIDENT ON BOTH THE FWD AND OUN SOUNDINGS SHOULD
WEAKEN AS THE SHORTWAVE OVER THE TX PANHANDLE LIFTS ENE...ALLOWING
ACTIVITY TO SPREAD EAST-NORTHEAST ACROSS THE NORTH AND NORTHWEST
COUNTIES THROUGH THE LATE MORNING AND AFTERNOON HOURS. A FEW
STORMS HAVE BECOME STRONG TO SEVERE...WHICH IS NOT SURPRISING
GIVEN THE 1000 J/KG OF ML CAPE. IN FACT WE JUST GOT A REPORT OF
PING PONG BALL SIZED HAIL IN THE TOWN OF LOVING IN YOUNG COUNTY. AN
ISOLATED SEVERE STORM OR TWO WILL REMAIN A DECENT POSSIBILITY AS
THE COMPLEX MIGRATES EAST-NORTHEAST ACROSS THE RED RIVER
REGION...BUT THE THREAT FOR WIDESPREAD SEVERE STORMS REMAINS LOW.
THE LATEST HI-RES MODEL DATA STILL KEEPS THE BRUNT OF THE ACTIVITY
NORTHWEST OF THE DALLAS-FORT WORTH METROPLEX...BUT A FEW STORMS
WILL PROBABLY MAKE IT INTO THE AREA BY MID AFTERNOON.
TEMPS MIGHT NEED TO ME ADJUSTED DOWN A TAD OVER THE NORTHWEST
COUNTIES WHERE RAIN-COOLED AIR WILL KEEP READINGS MAINLY IN THE
70S. OTHERWISE GRIDS ARE IN GOOD SHAPE.
30
&&
.AVIATION...
/12Z TAFS/
WIDESPREAD MVFR CIGS PREVAIL ACROSS NORTH TEXAS THIS MORNING WITH
MOIST SOUTHERLY FLOW WELL ESTABLISHED. A FAST MOVING BUT POTENT
DISTURBANCE WILL MOVE THROUGH THE SOUTHERN PLAINS TODAY RESULTING
IN SCATTERED SHOWERS AND THUNDERSTORMS. MOST OF THE ACTIVITY IS
EXPECTED TO REMAIN TO THE NORTHWEST OF THE MAJOR AIRPORTS HOWEVER
IT WILL BE CLOSE ENOUGH TO IMPACT OPERATIONS. SOME LIGHT SCATTERED
ACTIVITY IS ALREADY ONGOING FROM BRECKENRIDGE TO GAINESVILLE. WILL
MAINTAIN MVFR CIGS THROUGH THE MORNING AND FOR NOW WILL LEAVE THE
MENTION OF THUNDERSTORMS OUT WITH THE THINKING THAT THEY WILL
MAINLY BE OFF TO THE NORTHWEST. TIMING ON CONVECTIVE ACTIVITY
WOULD MOST LIKELY BE 18-21Z IN THE METROPLEX IF IT HOLDS TOGETHER
THIS FAR EAST. OTHERWISE...SOUTHERLY WINDS 15 TO 20KTS WILL
PERSIST. ANOTHER ROUND OF MVFR CIGS IS EXPECTED LATE TONIGHT.
DUNN
&&
.PREV UPDATE...
.UPDATE...
SHORTWAVE CONTINUES LIFTING NORTHEAST ACROSS THE TEXAS AND
OKLAHOMA PANHANDLES THIS MORNING. LATEST HIGH RES HRRR MODEL AND
NAM12 RUNS ARE PICKING UP ON THE LATEST TRENDS WITH THE WEST TX
STORMS THIS MORNING. THE TECH AND NCEP WRF MODELS PICK UP SOME OF
IT...BUT ARE TOO WEAK AS THE SHORTWAVE HAS IMPRESSIVE STRUCTURE ON
WATER VAPOR SATELLITE THIS MORNING.
12Z FWD SOUNDING DOES SHOW THE CAPPING INVERSION HAS STRENGTHENED
ONCE AGAIN WITHIN SWLY FLOW ALOFT...SO THE QUESTION REMAINS ON HOW
FAR SOUTH AND EAST TO BRING RAIN CHANCES. FOR NOW...HAVE KEPT THE
LINE THE SAME FOR RAIN CHANCES. HOWEVER...DID RAISE POPS ACROSS
THOSE AREAS WHERE THE CAP IS LIFTING AND MOISTENING TO HIGH CHANCE
AND LIKELY ACROSS NORTHWEST COUNTIES DUE TO STRENGTH OF ASCENT
AND EXPECTED INSTABILITY.
05/
&&
.PREV DISCUSSION... /ISSUED 339 AM CDT MON OCT 22 2012/
SHORTWAVE NOW SEEN MOVING PROGRESSIVELY NORTHEAST ACROSS NEW
MEXICO AND FAR WEST TEXAS THIS MORNING. SCATTERED THUNDERSTORMS
WERE IN PROGRESS FROM THE PERMIAN BASIN BACK INTO THE TRANS PECOS
MOVING FAIRLY QUICKLY. CURRENT HIGH RESOLUTION MODEL ANALYSIS
INDICATES LARGE SCALE ASCENT WILL AFFECT FAR NORTHWEST COUNTIES BY
MID-LATE MORNING. ASCENT WILL PROGRESS EAST ACROSS THE NORTHERN
COUNTIES THROUGH THE DAY WITH THE DISTURBANCE LIFTING ACROSS
OKLAHOMA/KANSAS. MORNING STRATUS HAS DEVELOPED SOUTHEAST OF A
SHERMAN...DFW...COMANCHE LINE WITH INCREASING HIGH CLOUDS IN
ADVANCE OF SHORTWAVE ACROSS THE NORTHEAST COUNTIES. WILL CONTINUE
A TIGHT GRADIENT ON RAIN CHANCES WITH THE FAR NORTHWEST AND RED
RIVER COUNTIES SEEING THE HIGHEST PROBABILITY THIS AFTERNOON AND
EVENING PER SYSTEM TRACK.
WITH REGARD TO SEVERE WEATHER...INSTABILITY WILL HINGE ON HOW MUCH
INSOLATION AND HEATING THESE AREAS CAN ACHIEVE BEFORE THE BEST
LIFT ARRIVES THIS AFTERNOON. THE CAP HAS LIFTED AND MOISTENED
SOMEWHAT THE PAST 24 HOURS ON THE LATEST FWD SOUNDING. DO FEEL THE
SOUTHEAST HALF OF THE CWA WILL LIKELY STAY CAPPED PER THE TRACK OF
THIS SHORTWAVE. IF STRATUS CAN STAY OUT OF OUR NORTHWEST COUNTIES...
THEN HIGHS WARMING INTO THE MID 80S THIS AFTERNOON MAY YIELD
ENOUGH INSTABILITY FOR A FEW STRONG TO MARGINALLY SEVERE STORMS.
WESTERLY BULK SHEAR OF 30-35 KTS INDICATE A MULTI- CELL SCENARIO
WITH THE POTENTIAL FOR A LOCALIZED DAMAGING WIND THREAT. WE DO NOT
EXPECT WIDESPREAD SEVERE WEATHER WITH THE LACK OF A SURFACE FOCUS
AND CLOUD COVER LIMITING THE POTENTIAL. THE SHORTWAVE AND
ASSOCIATED LIFT EXIT NORTHEAST AWAY FROM NORTH TEXAS OVERNIGHT
WITH RAIN CHANCES ENDING. OTHERWISE...A STRONG PRESSURE GRADIENT
WILL CONTINUE THE WINDY CONDITIONS TODAY WITH GUSTY SOUTH WINDS
15-25 MPH.
A FLAT SHORTWAVE RIDGE WILL DOMINATE ACROSS THE SOUTHERN PLAINS
DURING THE MIDDLE OF THE WEEK...AS DEEP ENERGY ALOFT ORGANIZES
ACROSS THE ROCKIES AND PACIFIC NORTHWEST. THIS WILL MAINTAIN LEE
CYCLOGENESIS ACROSS THE LEE OF THE ROCKIES WITH BREEZY AND WARM
CONDITIONS CONTINUING. A LEAD SHORTWAVE ROTATING EAST ACROSS THE
CENTRAL AND NORTHERN PLAINS ON THURSDAY WILL ASSIST IN MOVING A
STRONG COLD FRONT SOUTH TOWARD THE RED RIVER THURSDAY NIGHT.
MEDIUM RANGE MODELS ARE COMING INTO MORE AGREEMENT OF THE FRONT
CROSSING THE RED RIVER AND MOVING TOWARD THE I-20 CORRIDOR BY
DAYBREAK FRIDAY MORNING. BEST FORCING WILL REMAIN TO OUR NORTH ON
FRIDAY...BUT FORCING ALONG THE FRONT SHOULD LEND TO ISOLATED-
SCATTERED THUNDERSTORMS DURING THE DAY. ANALYSIS OF INSTABILITY
AND LAPSE RATES ALOFT DO NOT INDICATE A SEVERE WEATHER THREAT WITH
THE SYSTEM FRIDAY. A FEW STRONG STORMS ALONG THE FRONT WILL BE
POSSIBLE AS IT PROGRESSES QUICKLY SOUTH ACROSS THE CWA.
BRISK AND MUCH COOLER CONDITIONS ARE EXPECTED ACROSS NORTH TEXAS
INTO THE WEEKEND WITH STRONG CAA NOTED IN ALL THE MODELS. A
STRONG SHORTWAVE WILL ROTATE ACROSS THE SOUTHERN PLAINS FRIDAY
NIGHT AND SATURDAY MORNING WITH RAIN CHANCES CONTINUING. FORCING
ABOVE THE FRONTAL INVERSION WILL STEEPEN LAPSE RATES ALOFT ENOUGH
FOR EMBEDDED THUNDER FRIDAY NIGHT. MEANWHILE...LOWS BY SATURDAY
WILL FALL INTO THE 40S WITH BRISK CONDITIONS EXPECTED THE MAJORITY
OF THE WEEKEND. RAIN CHANCES END FROM WEST TO EAST DURING THE
DAY SATURDAY IN WAKE OF THE SHORTWAVE. HOWEVER...CONTINUING CAA
AND CLOUD COVER WILL RESULT IN HIGHS ONLY CREEPING INTO THE 50S
MOST AREAS.
CLEARING SKIES SATURDAY NIGHT AND DIMINISHING NORTH WINDS WILL
RESULT IN AREAS NORTH-WEST OF DFW FALLING INTO THE 30S BY SUNDAY
MORNING WITH LOWER-MID 40S ELSEWHERE. NORTH TEXAS WILL SEE MORE
SUNSHINE ON SUNDAY...BUT CONTINUING COOL WEATHER WITH HIGHS ONLY
CREEPING INTO THE LOWER 60S WITH A SECONDARY SURGE OF COOL
CANADIAN AIR BEING SUPPORTED BY CYCLONIC/NORTHWEST FLOW ALOFT.
LOWS IN THE 30S LOOK LIKELY BY NEXT MONDAY MORNING AND COULD NOT
RULE OUT SOME LIGHT FROST ACROSS THE NORTHERN COUNTIES. A DRY
FORECAST WILL CONTINUE INTO EARLY NEXT WEEK WITH ONLY A SLOW
MODERATION IN TEMPERATURES PER CONTINUED CYCLONIC NORTHWEST FLOW
ALOFT INDICATED BY ALL THE MODELS.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 86 70 85 68 86 / 30 10 5 0 0
WACO, TX 87 69 86 65 86 / 10 5 5 0 0
PARIS, TX 85 65 84 64 84 / 40 30 5 0 0
DENTON, TX 84 68 84 66 86 / 40 10 5 0 0
MCKINNEY, TX 84 67 84 65 85 / 40 20 5 0 0
DALLAS, TX 86 71 85 68 86 / 20 10 5 0 0
TERRELL, TX 86 68 84 66 85 / 10 10 5 0 0
CORSICANA, TX 86 68 85 66 85 / 10 5 5 5 5
TEMPLE, TX 87 68 85 64 86 / 10 5 5 5 5
MINERAL WELLS, TX 84 65 84 62 85 / 40 10 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
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.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/67
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
732 AM CDT MON OCT 22 2012
.UPDATE...
SHORTWAVE CONTINUES LIFTING NORTHEAST ACROSS THE TEXAS AND
OKLAHOMA PANHANDLES THIS MORNING. LATEST HIGH RES HRRR MODEL AND
NAM12 RUNS ARE PICKING UP ON THE LATEST TRENDS WITH THE WEST TX
STORMS THIS MORNING. THE TECH AND NCEP WRF MODELS PICK UP SOME OF
IT...BUT ARE TOO WEAK AS THE SHORTWAVE HAS IMPRESSIVE STRUCTURE ON
WATER VAPOR SATELLITE THIS MORNING.
12Z FWD SOUNDING DOES SHOW THE CAPPING INVERSION HAS STRENGTHENED
ONCE AGAIN WITHIN SWLY FLOW ALOFT...SO THE QUESTION REMAINS ON HOW
FAR SOUTH AND EAST TO BRING RAIN CHANCES. FOR NOW...HAVE KEPT THE
LINE THE SAME FOR RAIN CHANCES. HOWEVER...DID RAISE POPS ACROSS
THOSE AREAS WHERE THE CAP IS LIFTING AND MOISTENING TO HIGH CHANCE
AND LIKELY ACROSS NORTHWEST COUNTIES DUE TO STRENGTH OF ASCENT
AND EXPECTED INSTABILITY.
05/
&&
.AVIATION...
/12Z TAFS/
WIDESPREAD MVFR CIGS PREVAIL ACROSS NORTH TEXAS THIS MORNING WITH
MOIST SOUTHERLY FLOW WELL ESTABLISHED. A FAST MOVING BUT POTENT
DISTURBANCE WILL MOVE THROUGH THE SOUTHERN PLAINS TODAY RESULTING
IN SCATTERED SHOWERS AND THUNDERSTORMS. MOST OF THE ACTIVITY IS
EXPECTED TO REMAIN TO THE NORTHWEST OF THE MAJOR AIRPORTS HOWEVER
IT WILL BE CLOSE ENOUGH TO IMPACT OPERATIONS. SOME LIGHT SCATTERED
ACTIVITY IS ALREADY ONGOING FROM BRECKENRIDGE TO GAINESVILLE. WILL
MAINTAIN MVFR CIGS THROUGH THE MORNING AND FOR NOW WILL LEAVE THE
MENTION OF THUNDERSTORMS OUT WITH THE THINKING THAT THEY WILL
MAINLY BE OFF TO THE NORTHWEST. TIMING ON CONVECTIVE ACTIVITY
WOULD MOST LIKELY BE 18-21Z IN THE METROPLEX IF IT HOLDS TOGETHER
THIS FAR EAST. OTHERWISE...SOUTHERLY WINDS 15 TO 20KTS WILL
PERSIST. ANOTHER ROUND OF MVFR CIGS IS EXPECTED LATE TONIGHT.
DUNN
&&
.PREV DISCUSSION... /ISSUED 339 AM CDT MON OCT 22 2012/
SHORTWAVE NOW SEEN MOVING PROGRESSIVELY NORTHEAST ACROSS NEW
MEXICO AND FAR WEST TEXAS THIS MORNING. SCATTERED THUNDERSTORMS
WERE IN PROGRESS FROM THE PERMIAN BASIN BACK INTO THE TRANS PECOS
MOVING FAIRLY QUICKLY. CURRENT HIGH RESOLUTION MODEL ANALYSIS
INDICATES LARGE SCALE ASCENT WILL AFFECT FAR NORTHWEST COUNTIES BY
MID-LATE MORNING. ASCENT WILL PROGRESS EAST ACROSS THE NORTHERN
COUNTIES THROUGH THE DAY WITH THE DISTURBANCE LIFTING ACROSS
OKLAHOMA/KANSAS. MORNING STRATUS HAS DEVELOPED SOUTHEAST OF A
SHERMAN...DFW...COMANCHE LINE WITH INCREASING HIGH CLOUDS IN
ADVANCE OF SHORTWAVE ACROSS THE NORTHEAST COUNTIES. WILL CONTINUE
A TIGHT GRADIENT ON RAIN CHANCES WITH THE FAR NORTHWEST AND RED
RIVER COUNTIES SEEING THE HIGHEST PROBABILITY THIS AFTERNOON AND
EVENING PER SYSTEM TRACK.
WITH REGARD TO SEVERE WEATHER...INSTABILITY WILL HINGE ON HOW MUCH
INSOLATION AND HEATING THESE AREAS CAN ACHIEVE BEFORE THE BEST
LIFT ARRIVES THIS AFTERNOON. THE CAP HAS LIFTED AND MOISTENED
SOMEWHAT THE PAST 24 HOURS ON THE LATEST FWD SOUNDING. DO FEEL THE
SOUTHEAST HALF OF THE CWA WILL LIKELY STAY CAPPED PER THE TRACK OF
THIS SHORTWAVE. IF STRATUS CAN STAY OUT OF OUR NORTHWEST COUNTIES...
THEN HIGHS WARMING INTO THE MID 80S THIS AFTERNOON MAY YIELD
ENOUGH INSTABILITY FOR A FEW STRONG TO MARGINALLY SEVERE STORMS.
WESTERLY BULK SHEAR OF 30-35 KTS INDICATE A MULTI- CELL SCENARIO
WITH THE POTENTIAL FOR A LOCALIZED DAMAGING WIND THREAT. WE DO NOT
EXPECT WIDESPREAD SEVERE WEATHER WITH THE LACK OF A SURFACE FOCUS
AND CLOUD COVER LIMITING THE POTENTIAL. THE SHORTWAVE AND
ASSOCIATED LIFT EXIT NORTHEAST AWAY FROM NORTH TEXAS OVERNIGHT
WITH RAIN CHANCES ENDING. OTHERWISE...A STRONG PRESSURE GRADIENT
WILL CONTINUE THE WINDY CONDITIONS TODAY WITH GUSTY SOUTH WINDS
15-25 MPH.
A FLAT SHORTWAVE RIDGE WILL DOMINATE ACROSS THE SOUTHERN PLAINS
DURING THE MIDDLE OF THE WEEK...AS DEEP ENERGY ALOFT ORGANIZES
ACROSS THE ROCKIES AND PACIFIC NORTHWEST. THIS WILL MAINTAIN LEE
CYCLOGENESIS ACROSS THE LEE OF THE ROCKIES WITH BREEZY AND WARM
CONDITIONS CONTINUING. A LEAD SHORTWAVE ROTATING EAST ACROSS THE
CENTRAL AND NORTHERN PLAINS ON THURSDAY WILL ASSIST IN MOVING A
STRONG COLD FRONT SOUTH TOWARD THE RED RIVER THURSDAY NIGHT.
MEDIUM RANGE MODELS ARE COMING INTO MORE AGREEMENT OF THE FRONT
CROSSING THE RED RIVER AND MOVING TOWARD THE I-20 CORRIDOR BY
DAYBREAK FRIDAY MORNING. BEST FORCING WILL REMAIN TO OUR NORTH ON
FRIDAY...BUT FORCING ALONG THE FRONT SHOULD LEND TO ISOLATED-
SCATTERED THUNDERSTORMS DURING THE DAY. ANALYSIS OF INSTABILITY
AND LAPSE RATES ALOFT DO NOT INDICATE A SEVERE WEATHER THREAT WITH
THE SYSTEM FRIDAY. A FEW STRONG STORMS ALONG THE FRONT WILL BE
POSSIBLE AS IT PROGRESSES QUICKLY SOUTH ACROSS THE CWA.
BRISK AND MUCH COOLER CONDITIONS ARE EXPECTED ACROSS NORTH TEXAS
INTO THE WEEKEND WITH STRONG CAA NOTED IN ALL THE MODELS. A
STRONG SHORTWAVE WILL ROTATE ACROSS THE SOUTHERN PLAINS FRIDAY
NIGHT AND SATURDAY MORNING WITH RAIN CHANCES CONTINUING. FORCING
ABOVE THE FRONTAL INVERSION WILL STEEPEN LAPSE RATES ALOFT ENOUGH
FOR EMBEDDED THUNDER FRIDAY NIGHT. MEANWHILE...LOWS BY SATURDAY
WILL FALL INTO THE 40S WITH BRISK CONDITIONS EXPECTED THE MAJORITY
OF THE WEEKEND. RAIN CHANCES END FROM WEST TO EAST DURING THE
DAY SATURDAY IN WAKE OF THE SHORTWAVE. HOWEVER...CONTINUING CAA
AND CLOUD COVER WILL RESULT IN HIGHS ONLY CREEPING INTO THE 50S
MOST AREAS.
CLEARING SKIES SATURDAY NIGHT AND DIMINISHING NORTH WINDS WILL
RESULT IN AREAS NORTH-WEST OF DFW FALLING INTO THE 30S BY SUNDAY
MORNING WITH LOWER-MID 40S ELSEWHERE. NORTH TEXAS WILL SEE MORE
SUNSHINE ON SUNDAY...BUT CONTINUING COOL WEATHER WITH HIGHS ONLY
CREEPING INTO THE LOWER 60S WITH A SECONDARY SURGE OF COOL
CANADIAN AIR BEING SUPPORTED BY CYCLONIC/NORTHWEST FLOW ALOFT.
LOWS IN THE 30S LOOK LIKELY BY NEXT MONDAY MORNING AND COULD NOT
RULE OUT SOME LIGHT FROST ACROSS THE NORTHERN COUNTIES. A DRY
FORECAST WILL CONTINUE INTO EARLY NEXT WEEK WITH ONLY A SLOW
MODERATION IN TEMPERATURES PER CONTINUED CYCLONIC NORTHWEST FLOW
ALOFT INDICATED BY ALL THE MODELS.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 86 70 85 68 86 / 30 10 5 0 0
WACO, TX 87 69 86 65 86 / 10 5 5 0 0
PARIS, TX 85 65 84 64 84 / 40 30 5 0 0
DENTON, TX 84 68 84 66 86 / 40 10 5 0 0
MCKINNEY, TX 84 67 84 65 85 / 40 20 5 0 0
DALLAS, TX 86 71 85 68 86 / 20 10 5 0 0
TERRELL, TX 86 68 84 66 85 / 10 10 5 0 0
CORSICANA, TX 86 68 85 66 85 / 10 5 5 5 5
TEMPLE, TX 87 68 85 64 86 / 10 5 5 5 5
MINERAL WELLS, TX 84 65 84 62 85 / 40 10 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/05
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1047 AM CDT MON OCT 22 2012
.UPDATE...ACTIVE WX WILL BE OCCURRING TODAY AS SHOWERS AND
THUNDERSTORMS MAKE THEIR WAY THROUGH THE CWA. RADAR MOSAIC SHOWS A
LINE OF THUNDERSTORMS AND SHOWERS MOVING NORTHEAST AT AROUND 30
KTS WITH FREQ-CONT LIGHTNING CG STRIKES. LINE STRETCHES FROM FAR
SE MN...TO BALLTOWN/DUBUQUE... TO DIXON IL...TO HENRY IL. SHOWERS
AND THUNDERSTORMS HAVE BEEN PRODUCING MAINLY MODERATE HOURLY
RAINFALL RATES. FURTHER...THERE HAVE BEEN REPORTS OF HAIL UPSTREAM
EARLIER IN THE MORNING...UP TO HALF INCH DIAMETER. AS SUCH...RAIN
RATES AND SMALL HAIL ARE THE MAIN CONCERNS CURRENTLY. WX/POPS HAVE
BEEN WALKED THROUGH INTO THE AFTERNOON AS IT HAS BEEN MOVING
STEADILY...ALONG WITH DECENT HANDLING BY SOME OF THE MESOSCALE
MODELS...E.G. HRRR AND NCEP SPC 4KM WRF. THOUGH THE LLJ WILL
WEAKEN AND BE SOUTH OF CWA...DECENT S/W TROUGH...ELEVATED
INSTABILITY...AND WITH MOISTURE IN THE SOUNDINGS/PWAT
VALUES...PROGGED AROUND 1.5 AT NOON...THE AREA SHOULD RECEIVE SOME
BENEFICIAL RAINFALL WITH THUNDER GOING INTO THE AFTERNOON.
OUTSIDE WX AND POPS...THE OTHER MAIN CONCERN IS HIGH TEMPERATURES.
GIVEN THERE WILL BE MAINLY OVERCAST SKIES...PRECIP...AND ON-SHORE
FLOW OFF THE COOLER LAKE...SOME UNCERTAINTY EXISTS. THOUGH GIVEN
THE LOW-LEVEL WAA AND WARM TEMPS ALOFT...925 HPA RANGE 14-17 C
THOUGH WITH A VERY MOIST SOUNDING...AND WHAT THE INHERITED GRIDS
WERE...HIGHS HAVE ONLY BEEN MODIFIED SLIGHTLY. WILL BE MONITORED
CLOSELY AS THE DAY PROGRESSES.
&&
.AVIATION/18Z TAFS/...LINE OF THUNDERSTORMS IS CURRENTLY PUSHING
INTO THE FORECAST AREA. UPDATED TIMING AND IMPACT OF STORMS IN
TAFS...AS THIS HAS BEEN A FAIRLY STEADY MOVING LINE. STILL
EXPECTING LINGERING CHANCE FOR SHOWERS AND STORMS THROUGH THE
REMAINDER OF THE DAY...AND THEN AGAIN TONIGHT AND TUESDAY AS A
FRONTAL BOUNDARY REMAINS IN THE AREA.
CIGS AND VSBYS WILL GO DOWN AS THE STORMS ROLL THROUGH TODAY.
WILL THEN SEE LOWER CIGS/VSBYS AT TIMES THROUGH AT LEAST TOMORROW
MORNING...AS HIGHER DEWPOINTS ADVECT INTO THE AREA AND CHANCE FOR
PRECIP LINGERS.
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT MON OCT 22 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
GOES SOUNDER INDICATES PRECIPITABLE WATER VALUES HAVE ALREADY
DOUBLED IN LAST 24 HOURS TO AROUND 1 INCH OVER SOUTHERN WI.
INCREASING SOUTH WINDS OVER CENTRAL CONUS AHEAD OF LONG WAVE
TROUGH AMPLIFICATION OUT WEST CONTINUE TO PULL DEEPER LOW LEVEL
MOISTURE NORTHWARD. SURFACE DEWPOINTS HAVE RISEN INTO THE MIDDLE
50S TO AROUND 60 AS CLOSE AS CENTRAL IA...AHEAD OF APPROACHING
WEAK SURFACE FRONT. THIS ADDED MOISTURE AND STRENGTHENING LOW
LEVEL JET PRODUCING INCREASING CONVECTION OVER SW IA/NRN MO.
UPSTREAM MID LEVEL SHORT WAVE CAUGHT IN SOUTHWEST FLOW ALSO
CONTRIBUTING LIFT TO CONVECTION. PER IR IMAGERY SHORT WAVE
UPSTREAM FROM CONVECTION OVER SOUTHEAST NE AREA. DESPITE WEAKENING
OF LOW LEVEL JET TO THE SOUTH OF WI THIS MORNING...WAVE EXPECTED
TO CONTINUE NORTHEAST ACROSS SRN WI/NRN IL AREA LATER THIS MRNG
AND AFTN. WITH MOISTURE ALREADY IN PLACE...WL CONTINUE CATEGORICAL
POPS FROM MID-MRNG THRU THE AFTN. WITH ELEVATED INSTABILITY STILL
EXPECTED TO SURGE INTO SRN WI...WL CONTINUE T MENTION. MUCAPES MAY
REACH 1000 J IN THE SOUTH. HIGH TEMPERATURES TRICKY TODAY DUE TO
THICKENING CLOUDS AND PRECIP...AND COOL NEARSHORE LAKE MI WATERS.
SYNOPTIC SCALE LIFT ASSOCIATED WITH WAVE PUSHES OFF TO THE EAST
DURING THE LATE AFTN AND EVE. HOWEVER LINGERING FRONTAL BOUNDARY
AND LOW LEVEL CONVERGENCE IN THE AREA SHOULD STILL TRIGGER SCT TO
NUMEROUS -SHRA FOR A TIME...ALONG WITH PATCHY DRIZZLE LATER IN THE
NIGHT. WL CONTINUE SMALL THREAT FOR THUNDER IN SOUTH LATER TNGT AS
LOW LEVEL JET GETS REENERGIZED JUST TO THE SOUTH. LIGHT BOUNDARY
LAYER WINDS AND DEEP MOISTURE SHOULD RESULT IN FOG AND MAYBE DENSE
FOG DURING THE LATE NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
NAM/GFS/ECMWF/CANADIAN MODELS SHOW WARM FRONT MOVING NORTH OF THE
AREA THROUGH THE DAY TUESDAY. NAM IS SLOWER THAN THE OTHER MODELS
IN MOVING THE FRONT TO THE NORTH. NAM FORECAST SOUNDINGS ARE AGAIN
SHOWING A LOT OF ELEVATED AND MEAN LAYER CAPE VERSUS THE GFS
SOUNDINGS.
GIVEN THE STRONG WARM AIR AND MOISTURE ADVECTION INTO THE
REGION...WOULD LEAN MORE TOWARD THE LOWER INSTABILITY VALUES OF
THE GFS SOUNDINGS...WHICH HAVE A MORE REALISTIC TEMPERATURE
STRUCTURE. WILL CONTINUE THE CHANCE POPS FOR TUESDAY...WITHIN WARM
AIR/MOISTURE ADVECTION REGIME. WARM TEMPERATURES INTO THE 70S ARE
EXPECTED SOUTH OF THE WARM FRONT...WITH SOUTH WINDS.
THE WARM FRONT THEN SHIFTS TO THE NORTHWEST AND LINGERS THERE
TUESDAY NIGHT INTO WEDNESDAY NIGHT. SOUTH WINDS CONTINUE TO BRING
WARM TEMPERATURES INTO THE AREA DURING THIS TIME...WITHIN THE WARM
SECTOR AIRMASS. GFS FORECAST SOUNDINGS SHOW CAPPING OF SURFACE
BASED AIR PARCELS DURING THIS TIME...WITH NAM SOUNDINGS AGAIN
SHOWING A LOT OF MEAN LAYER AND ELEVATED CAPE. LEANED TOWARD THE
GFS SOUNDINGS FOR THIS PERIOD AS WELL.
WILL TRY TO GO WITH LOWER END POPS FOR THIS PERIOD...AS WARM
SECTOR SHOULD BE CAPPED. AN EXCEPTION MAY BE WEDNESDAY AFTERNOON
IN NORTHWESTERN SECTIONS OF THE AREA...WHERE THE SOUTHWESTERLY LOW
LEVEL JET NOSE FOCUSES...WITH SOME FOCUSED WARM AIR ADVECTION. IT
IS ALSO POSSIBLE THAT THE CAP WOULD LEAD TO DRY CONDITIONS ACROSS
THE WHOLE AREA AS WELL.
ANOTHER WARM DAY FOR WEDNESDAY...WITH 70S FOR HIGHS ONCE AGAIN.
MAY SEE ANOTHER ROUND OF FOG...SOME POSSIBLY DENSE...TUESDAY NIGHT
WITH WARM AND HUMID AIRMASS IN PLACE.
THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS MEDIUM.
GFS/ECMWF AGREE FAIRLY WELL WITH TIMING OF STRONG COLD FRONT
THROUGH THE AREA ON THURSDAY. STRONG LOW LEVEL FRONTOGENESIS WITH
THE FRONT SHOULD INTERACT WITH THE WARM AND MOIST AIRMASS AHEAD OF
IT TO BRING SHOWERS AND THUNDERSTORMS.
STRONG TO SEVERE STORMS REMAIN POSSIBLE DURING THIS TIME...AS
STRONG DEEP LAYER WIND SHEAR IS IN PLACE. DEGREE OF INSTABILITY IS
STILL IN QUESTION...AND WILL DEPEND ON HOW MUCH CLOUD COVER IS
ACROSS THE AREA. TIMING OF FRONT DURING THE DAY ALSO HELPS WITH
SEVERE CHANCES. WILL CONTINUE TO MENTION POTENTIAL IN HAZARDOUS
WEATHER OUTLOOK FOR NOW.
TRAILING VORTICITY MAXIMUM SLIDES NORTHEAST THROUGH THE AREA
FRIDAY NIGHT INTO SATURDAY...STRONGER ON THE GFS THAN THE ECMWF.
THE GFS CONTINUES TO SHOW QPF WITH THIS FEATURE DURING THIS
TIME...WITH THE ECMWF DRY. WILL CONTINUE TO USE CONSENSUS OF
MEDIUM RANGE MODEL POPS. STRONG COLD AIR ADVECTION BEHIND THE
FRONT THURSDAY NIGHT THROUGH SATURDAY WILL BRING MUCH COLDER
TEMPERATURES TO THE AREA. THIS MAY LEAD TO A MIX OF RAIN AND SNOW
SHOWERS LATER FRIDAY NIGHT.
QUIET WEATHER THEN EXPECTED THROUGH THE REST OF THE WEEKEND. WENT
WITH CONSENSUS POPS AND TEMPERATURES DURING THIS TIME.
AVIATION/12Z TAFS/...EXPECT MVFR CIGS TO ACCOMPANY SHOWERS AND
THUNDERSTORMS THAT WILL SWEEP ACROSS TAF SITES LATER THIS MORNING
AND AFTERNOON. LIGHTER BOUNDARY LAYER WINDS...MOIST LOW LEVELS AND
LINGERING AREAS OF LIGHT PRECIP WILL RESULT IN LOW CIGS OF IFR OR
LOWER FOR MOST OF TNGT. DENSE FOG MAY ALSO DEVELOP.
MARINE...WINDS EXPECTED TO REMAIN LIGHTER THROUGH TUESDAY AS
FRONTAL BOUNDARY SETS UP OVER SOUTHERN WI AND LOWER LAKE MI. MAIN
PROBLEM WILL BE DENSE FOG THREAT. WARM...MOIST AIR EXPECTED TO
SURGE OVER SOUTHERN LAKE LATE TODAY AND TONIGHT AND LINGER INTO
THURSDAY. LATEST MODIS IMAGERY AND BUOY SEA SURFACE TEMPERATURE
DATA HAS THE LAKE SURFACE TEMPERATURE RANGING FROM THE MIDDLE 50S
IN THE MID LAKE TO THE MIDDLE 40S IN PORTIONS OF THE NEAR SHORE
SHALLOWER WATERS. DEWPOINTS WL LIKELY RISE INTO THE MIDDLE 50S TO
LOWER 60S IN THE NEXT 12-24 HOURS. HENCE THIS MILD MOIST AIR WOULD
BE COOLED OVER THE LAKE POSSIBLY RESULTING IN ADVECTION DENSE FOG.
SOUTHEAST WINDS WILL LIKELY PULL THE 50-55 DEGREE WATER INTO THE
NEARSHORE AREAS...REDUCING THE TEMPERATURE GRADIENT. SO FOR NOW WL
MENTION AREAS OF DENSE FOG LATE TNGT BUT HOLD OFF ON ANY ADVY.
COOLER NEARSHORE WATERS MAY RESULT IN MORE ELY SFC WINDS FOR A
TIME LATER TODAY AND TNGT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET/DDV
TODAY/TONIGHT AND AVIATION/MARINE...MBK
TUESDAY THROUGH SUNDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
634 AM CDT MON OCT 22 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
351 AM CDT MON OCT 22 2012
AT 3 AM...A BAND OF SHOWERS AND THUNDERSTORMS WERE DEVELOPING
ALONG A WARM FRONT ACROSS SOUTHWEST IOWA AND NORTHERN MISSOURI.
THE LATEST RAP SHOWS THAT THERE IS STRONG 900 TO 800 MB
FRONTOGENESIS. IT SHOWS THAT AS THIS BAND MOVES NORTHEAST TOWARD
THE AREA THAT THIS FRONTOGENESIS GRADUALLY WEAKENS. IN
ADDITION...THESE STORMS WILL BE MOVING INTO AN AREA OF LESS
INSTABILITY. THEREFORE THINKING THAT THE THUNDERSTORMS WILL BECOME
MORE ISOLATED AS THEY MOVE THROUGH OUR AREA THIS MORNING AND EARLY
THIS AFTERNOON. WITH THE BEST MOISTURE TRANSPORT MAINLY OVER
NORTHERN ILLINOIS...THE HIGHEST PRECIPITATION PROBABILITIES SHOULD
BE LOCATED ACROSS NORTHEAST IOWA...AND SOUTHWEST AND CENTRAL
WISCONSIN. MANY OF THE MESO MODELS SUGGEST THAT THE CONVECTION
WILL EVOLVE INTO A LINE AS IT MOVES NORTHEAST THROUGH THE AREA. AS
A RESULT...TRIED TO TIME THE HIGHEST PRECIPITATION PROBABILITIES
TO ITS PARENT SHORT WAVE TROUGH. BUFKIT SOUNDINGS SHOW VERY SKINNY
CAPE ACROSS THE AREA...SO THE CHANCES OF ANY HAIL WITH ANY OF
THESE STORMS LOOKS RATHER MINUTE.
FOR TONIGHT...THE 22.00Z MODELS ARE IN FAIRLY GOOD AGREEMENT THAT
A WEAK LOW PRESSURE SYSTEM AND ITS WARM FRONT WILL APPROACH THE
AREA. THERE IS SOME WEAK TO MODERATE OMEGA AND ISENTROPIC LIFT
ASSOCIATED WITH THIS SYSTEM...SO EXPECT SOME LIGHT RAIN OR DRIZZLE
ACROSS THE AREA. THE SOUNDINGS SHOW THAT THERE WILL BE SOME
INSTABILITY ALOFT...BUT THERE IS SOME QUESTION WHETHER IT CAN BE
TAPPED. AS A RESULT...JUST LEFT ISOLATED THUNDERSTORMS IN THE FORECAST.
ON TUESDAY...THE MODELS SHOW THAT THE WARM FRONT WILL MOVE SLOWLY
NORTHEAST THROUGH THE AREA. THIS FRONT WILL USHER IN LOWER 60 DEW
POINTS AND TEMPERATURES IN THE 70S. IT WILL ALSO BE THE FOCUS FOR
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
ON TUESDAY NIGHT...BOTH THE NAM/WRF AND ECMWF SUGGEST THAT ANOTHER
SHORT WAVE TROUGH WILL MOVE NORTHEAST THROUGH THE AREA. DUE TO
THIS...KEPT A SLIGHT CHANCE OF PRECIPITATION IN THE FORECAST.
ON WEDNESDAY AFTERNOON AND EVENING...THE MODELS SHOW THAT A STRONG
COLD FRONT WILL MOVE EAST INTO THE FORECAST AREA. THE GEM AND
NAM/WRF ARE THE FASTEST AT MOVING THE COLD FRONT THROUGH THE AREA.
MEANWHILE THE ECMWF IS THE SLOWEST. THIS WILL GREATLY AFFECT THE
LOW TEMPERATURES ON WEDNESDAY NIGHT. IN ADDITION...WILL HAVE TO WATCH THIS
COLD FRONT FOR THE POSSIBILITY OF SEVERE WEATHER. THE NAM/WRF
SHOWS A LOW PRESSURE SYSTEM MOVING ALONG THIS FRONT WHICH HELPS
INCREASE THE LOW LEVEL SHEAR ACROSS THE AREA. THE 0-1 KM BULK SHEAR
EXCEEDS 25 KNOTS AND THE 0-1 KM HELICITY EXCEEDS 300 M2/S2 FROM
NORTH CENTRAL IOWA NORTHEAST INTO NORTHWEST WISCONSIN. THE ML
CAPES CLIMBS APPROACHES 2K. THIS HELPS THE SIGNIFICANT TORNADO
PARAMETER CLIMB TO 5. THE GFS ALSO SHOWS A POSSIBILITY OF
TORNADOES...BUT ITS VALUES ARE MUCH WEAKER. THE TORNADO
POSSIBILITIES WILL DEPEND A LOT ON WHETHER THE STORMS ARE ABLE TO
BECOME SURFACE BASED OR NOT. THE NAM/WRF WOULD SUGGEST THAT THEY
WILL BECOME SURFACE BASED DURING THE AFTERNOON. MEANWHILE THE GFS
WOULD SAY THAT THEY WILL REMAIN ELEVATED. FOR THE TIME
BEING...WILL JUST MENTION THE POSSIBILITY OF SEVERE WEATHER IN THE
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...THURSDAY THROUGH SUNDAY
351 AM CDT MON OCT 22 2012
ON THURSDAY...STRONG COLD AIR ADVECTION WILL MOVE INTO THE AREA.
AS THIS OCCURS...EXPECT THE TEMPERATURES TO FALL RAPIDLY INTO THE
40S BY THE AFTERNOON.
ON FRIDAY NIGHT...BOTH THE GFS AND ECMWF HAVE SHIFTED A LOW
PRESSURE SYSTEM FURTHER SOUTHEAST AWAY FROM THE AREA. MEANWHILE
THE GEM DEVELOPS A WAVE ALONG THE FRONT TO OUR SOUTHEAST AND THIS
BRINGS THE PRECIPITATION NORTHWEST INTO NORTHEAST IOWA AND
SOUTHWEST AND CENTRAL WISCONSIN. THIS IS IMPORTANT BECAUSE THE
TEMPERATURES ALOFT WILL BE COLD ENOUGH FOR SOME SNOW. FOR THE TIME
BEING...JUST WENT WITH THE SLIGHT CHANCES THAT WERE IN THE ALL BLEND.
&&
.AVIATION...TODAY AND TONIGHT
634 AM CDT MON OCT 22 2012
CEILING HEIGHTS AND THE POTENTIAL FOR IFR CONDITIONS TONIGHT THE
MAIN CONCERN. INFLUX OF LOW LEVEL MOISTURE WILL CONTINUE THROUGH
THE TAF PERIOD. CONVECTION OVER IOWA PUSHING NORTHEAST ON NOSE OF
MOISTURE TRANSPORT. EXPECT THIS AREA TO CONTINUE TO PUSH NORTH
AFFECTING THE TAF SITES BETWEEN 13Z-16Z. CEILINGS WILL THEN DROP
INTO THE MVFR CATEGORY AS THE RAIN BEGINS AND WILL CONTINUE
THROUGH MUCH OF THE DAY. BUFKIT SOUNDINGS FROM BOTH THE GFS AND
NAM SHOWING LOW LEVEL SATURATION TONIGHT WITH ANOTHER PUSH OF
MOISTURE NORTHWARD AHEAD OF A WARM FRONT. EXPECT
CEILINGS/VISIBILITIES TO FALL THROUGH THE EVENING HOURS WITH IFR
CONDITIONS LIKELY AT KRST AND POSSIBLY KLSE. FOR NOW WILL ONLY
MENTION IT AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
313 AM CDT MON OCT 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
601 AM MDT MON OCT 22 2012
.AVIATION...12Z TAF ISSUANCE...
OBS AND SATELLITE IMAGERY GENERALLY SHOW IFR CIGS ACROSS THE
NEBRASKA PANHANDLE. LOW CLOUDS HAVE BEEN TRYING TO PUSH INTO
SOUTHEAST WYOMING BUT ARE NOT MAKING MUCH HEADWAY OVER THE PAST
FEW HOURS. KSNY IS SEEING THE LOWEST VIS/CIGS AND WILL CONTINUE
THIS THROUGH THE LATE MORNING. LOW CLOUDS WILL PERSIST THROUGH
AROUND 18Z BEFORE DISSIPATING. VFR CONDITIONS WILL OCCUR AT THE WY
SITES THROUGH THE ENTIRE TAF PERIOD. SOUTHWEST WINDS WILL BECOME
WINDY THIS AFTERNOON TO THE WEST OF THE LARAMIE RANGE...WITH GUSTS
OCCASIONALLY REACHING 30-35 KTS.
&&
.PREV DISCUSSION... /ISSUED 427 AM MDT MON OCT 22 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY...
BUILDING DOWN STRATUS HAS LED TO A FOGGY START TO THE DAY FOR
PORTIONS OF THE EASTERN PLAINS GENERALLY BELOW 5 KFT. THE FOG
PRODUCT CONTINUES TO SHOW BANK OF STRATUS/FOG BACKING
WEST/SOUTHWEST. LATEST HRRR OUTPUT SUGGEST THE WESTWARD PROGRESS
OF THE FOG SHOULD SLOW TOWARDS DAYBREAK. FOG WILL BEGIN TO LIFT BY
LATE MORNING AS THE LLVLS BEGINS TO MIX AND BECOME COUPLED.
OTHERWISE AN AREA OF LIGHT SHOWERS WILL CONTINUE ACROSS CARBON AND
CONVERSE COUNTIES THIS MORNING AS AN EMBEDDED SHORTWAVE LIFTS
NORTHEAST. BEST MOISTURE WILL BE HELD BACK ACROSS WESTERN
WYOMING...SO THESE SHOWERS WILL REMAIN LIGHT PRODUCING LITTLE TO
NO PRECIPITATION. TEMPERATURES WILL BE SLIGHTLY WARMER TODAY AS
H7 TEMPERATURES CLIMB NEAR 6-7C.
ATTENTION THEN TURNS TO A POSSIBLE HIGH WIND EVENT FOR WIND PRONE
AREAS LATER LATE THIS EVENING THROUGH MID-MORNING ON TUESDAY.
LATEST MODEL GUIDANCE IS CONSISTENT IN PAINTING A POCKET OF 50-60
KNOT H7 WINDS DEVELOPING ACROSS CARBON COUNTY AND THE NRN LARAMIE
RANGE AFTER 03Z. THE PROGD KCAG-KCPR GRADIENTS REMAIN ON THE LOW-
SIDE OF TYPICAL WARNING CRITERIA...HOVERING BETWEEN 47 AND 53
METERS AT H85 AND H7 BY MIDNIGHT. HOWEVER...THESE MAY BE OVERCOME
AS THE SUBSIDING RFQ OF A 110 KNOT JET STREAK WORKS INTO THE AREA
TONIGHT. IN ADDITION...THE DEVELOPMENT OF A STABLE LAYER DOWN TO
AROUND H7 WILL AID IN THE POTENTIAL FOR STRONG WINDS AT THE
TYPICAL WIND PRONE AREAS OF ARLINGTON AND BORDEAUX. SO...HAVE
ISSUED A HIGH WIND WATCH FOR THESE AREAS FROM 9P TONIGHT THROUGH
9A TUESDAY. ALTHOUGH WINDS WILL REMAIN BREEZY ACROSS OTHER LOWER
ELEVATIONS OF CARBON/ALBANY COUNTIES TONIGHT...DO NOT ANTICIPATE
THAT THESE AREAS WILL REMAIN COUPLED THRU THE OVERNIGHT HOURS AND
THUS SHOULD NOT SEE THESE STRONG WINDS. STRONGEST WINDS WILL
DEPART ON TUESDAY SO ALTHOUGH WINDS WILL REMAIN BREEZY...EXPECT
THEM TO LESSEN THROUGH THE DAY. PRECIPITATION CHANCES WILL
INCREASE ACROSS CARBON...CONVERSE AND NIOBRARA COUNTIES ON TUESDAY
AFTERNOON AS THIS AREA REMAINS ON THE WARM SIDE OF THE STRONG SW/NE
ORIENTED JET STREAK. TEMPERATURES WILL BE COOLER WEST OF THE
LARAMIE RANGE FOR TUESDAY WHILE EASTERN PLAINS WILL REMAIN WARM.
BY WEDNESDAY...THE NEXT CYCLONICALLY CURVED JET STREAK WILL NOSE
INTO COLORADO PLACING THE FAVORABLE LFQ OVER THE CWA. THIS WILL
COMBINE WITH A SURFACE COLD FRONT THAT WILL DROP SOUTH THROUGH THE
AREA DURING THE DAY. BEHIND THE FRONT...UPSLOPE FLOW ALONG WITH
THE LAGGING MID-LEVEL FRONTOGENESIS WILL COMBINE WITH OVERRUNNING
MOISTURE AND THE AFOREMENTIONED LFQ TO BEGIN TO PRODUCE MORE
WIDESPREAD PRECIPITATION ESPECIALLY DURING THE AFTERNOON HOURS.
FORTUNATELY...TEMPERATURES WILL BE WARM ENOUGH FOR PRECIPITATION
TO REMAIN ALL RAIN AT THIS POINT. THIS CHANGES IN SUBSEQUENT
PERIODS IN THE LONG TERM HOWEVER. UNSETTLED WEATHER ALONG WITH
COOLER AIR...WILL HOLD TEMPERATURES DOWN ON WEDNESDAY...WITH 40S
FOR NORTHERN AND WESTERN ZONES...AND 50S ELSEWHERE.
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...
MODELS CONTINUE TO HONE IN ON THE WED NIGHT PERIOD AS A
FAVORABLE TIME FOR WIDESPREAD PRECIP OVER THE CWA. THE GFS AND
ECMWF BOTH SHOW A STRONG SHORTWAVE MOVING OVER NORTHERN COLORADO ON
WED NIGHT WITH MOST OF THE CWA IN THE LEFT EXIT REGION OF THE 250MB
JET BETWEEN 00-12Z THURS. THICKNESSES AND SOUNDINGS SUGGEST THAT
SNOW WILL BE THE PRECIP TYPE ON WED NIGHT. PRECIP COULD START OUT
INITIALLY AS A MIX OF RAIN AND SNOW IN THE NEBRASKA PANHANDLE ON WED
EVENING...THEN TRANSITION QUICKLY TO SNOW AS COLD AIR ADVECTION
CONTINUES THROUGH THE EARLY NIGHT HOURS. MODEL QPF CONSENSUS IS IN
THE 0.25-0.50 INCH RANGE FOR THIS FIRST WAVE. SHORTWAVE AND ITS
ASSOCIATED DEEP LAYER LIFT MOVES EAST OF THE REGION ON THURS MORNING
WITH SNOW RATES DROPPING OFF. THE MODELS SHOW BROAD CYCLONIC FLOW
ON THURS WITH LLVL UPSLOPE ALONG AND EAST OF THE LARAMIE RANGE.
DROPPED HIGH TEMPERATURES ON THURS INTO THE LOW-TO-MID 30S OVER THE
PLAINS WITH CLOUD COVER...UPSLOPE...AND SNOW COVER MAKING IT
DIFFICULT TO GET MUCH WARMING. ALTHOUGH UPPER LEVEL FORCING IS WEAK
ON THURS...LLVL UPSLOPE COULD BE SUFFICIENT TO GENERATE SOME WEAK
SNOW SHOWERS/FLURRIES MAINLY ALONG THE LARAMIE RANGE.
THE NEXT STRONG SHORTWAVE IN THE CYCLONIC MIDLEVEL FLOW IS PROGGED
TO TREK FROM UTAH INTO COLORADO ON THURS NIGHT. WITH DEEP LAYER
UPWARD MOTION INCREASING ON THURS NIGHT...AND LLVL UPSLOPE ALREADY
IN PLACE...WOULD EXPECT ANOTHER ROUND OF SNOW ESPECIALLY OVER THE
SOUTHERN ZONES. NEED TO CONTINUE TO MONITOR THE TRACK OF THIS
SHORTWAVE AS A SHIFT TO THE NORTH OR SOUTH WOULD OBVIOUSLY HAVE
IMPLICATIONS ON QPF AMOUNTS. SNOW COMES TO AN END BY MIDDAY FRI
AS THE FORCING EXITS THE AREA. ANOTHER COLD DAY ON FRI WITH
TEMPERATURES AROUND 25-30 DEGREES BELOW NORMAL FOR LATE OCTOBER.
NORTHWESTERLY MIDLEVEL FLOW BECOMES ESTABLISHED OVER SOUTHEAST
WYOMING ON SAT WITH DRYING IN LOW AND MIDLEVELS. NOT GOING TO SEE
ANY BIG WARMUP UNTIL SUN...WHEN THE SFC HIGH PRESSURE OVER THE
PLAINS IS REPLACED BY A DEVELOPING SFC TROUGH AND INCREASINGLY ZONAL
FLOW ALOFT.
FIRE WEATHER...
A FAIRLY ACTIVE WEEK TAKING SHAPE ACROSS THE DISTRICT WITH BREEZY
TO LOCALLY WINDY CONDITIONS FOR AREAS ALONG AND WEST OF THE
LARAMIE RANGE FOR MONDAY AND TUESDAY FOLLOWED BY A PROLONGED
PRECIPITATION EVENT THAT WILL BEGIN AS EARLY AS WEDNESDAY
AFTERNOON AND CONTINUE INTO FRIDAY. IF CURRENT FORECASTS HOLD THIS
WILL BRING IN MUCH COLDER AIR ALONG WITH LIGHT TO MODERATE SNOW
ACCUMULATIONS. BEFORE THEN...TEMPERATURES WILL CONTINUE TO BE
UNSEASONABLY WARM TODAY AND TUESDAY WITH HIGHS THAT WILL CLIMB
INTO THE 60S AND 70S. WINDS MAY BECOME VERY STRONG ACROSS WIND
PRONE AREAS NEAR ARLINGTON AND BORDEAUX TONIGHT WITH WIND GUSTS TO
60 MPH POSSIBLE. MINIMUM RELATIVE HUMIDITIES SHOULD HOLD IN THE
20S AND 30S FOR BOTH TODAY AND TUESDAY. HOWEVER...THESE WILL
INCREASE AS COLDER UNSETTLED CONDITIONS WORK IN FOR THE LATTER
HALF OF THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM 9 PM MONDAY TO 9 AM TUESDAY FOR WYZ106-
WYZ110.
NE...NONE.
&&
$$
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
427 AM MDT MON OCT 22 2012
.SHORT TERM...ODAY THROUGH WEDNESDAY...
BUILDING DOWN STRATUS HAS LED TO A FOGGY START TO THE DAY FOR
PORTIONS OF THE EASTERN PLAINS GENERALLY BELOW 5 KFT. THE FOG
PRODUCT CONTINUES TO SHOW BANK OF STRATUS/FOG BACKING
WEST/SOUTHWEST. LATEST HRRR OUTPUT SUGGEST THE WESTWARD PROGRESS
OF THE FOG SHOULD SLOW TOWARDS DAYBREAK. FOG WILL BEGIN TO LIFT BY
LATE MORNING AS THE LLVLS BEGINS TO MIX AND BECOME COUPLED.
OTHERWISE AN AREA OF LIGHT SHOWERS WILL CONTINUE ACROSS CARBON AND
CONVERSE COUNTIES THIS MORNING AS AN EMBEDDED SHORTWAVE LIFTS
NORTHEAST. BEST MOISTURE WILL BE HELD BACK ACROSS WESTERN
WYOMING...SO THESE SHOWERS WILL REMAIN LIGHT PRODUCING LITTLE TO
NO PRECIPITATION. TEMPERATURES WILL BE SLIGHTLY WARMER TODAY AS
H7 TEMPERATURES CLIMB NEAR 6-7C.
ATTENTION THEN TURNS TO A POSSIBLE HIGH WIND EVENT FOR WIND PRONE
AREAS LATER LATE THIS EVENING THROUGH MID-MORNING ON TUESDAY.
LATEST MODEL GUIDANCE IS CONSISTENT IN PAINTING A POCKET OF 50-60
KNOT H7 WINDS DEVELOPING ACROSS CARBON COUNTY AND THE NRN LARAMIE
RANGE AFTER 03Z. THE PROGD KCAG-KCPR GRADIENTS REMAIN ON THE LOW-
SIDE OF TYPICAL WARNING CRITERIA...HOVERING BETWEEN 47 AND 53
METERS AT H85 AND H7 BY MIDNIGHT. HOWEVER...THESE MAY BE OVERCOME
AS THE SUBSIDING RFQ OF A 110 KNOT JET STREAK WORKS INTO THE AREA
TONIGHT. IN ADDITION...THE DEVELOPMENT OF A STABLE LAYER DOWN TO
AROUND H7 WILL AID IN THE POTENTIAL FOR STRONG WINDS AT THE
TYPICAL WIND PRONE AREAS OF ARLINGTON AND BORDEAUX. SO...HAVE
ISSUED A HIGH WIND WATCH FOR THESE AREAS FROM 9P TONIGHT THROUGH
9A TUESDAY. ALTHOUGH WINDS WILL REMAIN BREEZY ACROSS OTHER LOWER
ELEVATIONS OF CARBON/ALBANY COUNTIES TONIGHT...DO NOT ANTICIPATE
THAT THESE AREAS WILL REMAIN COUPLED THRU THE OVERNIGHT HOURS AND
THUS SHOULD NOT SEE THESE STRONG WINDS. STRONGEST WINDS WILL
DEPART ON TUESDAY SO ALTHOUGH WINDS WILL REMAIN BREEZY...EXPECT
THEM TO LESSEN THROUGH THE DAY. PRECIPITATION CHANCES WILL
INCREASE ACROSS CARBON...CONVERSE AND NIOBRARA COUNTIES ON TUESDAY
AFTERNOON AS THIS AREA REMAINS ON THE WARM SIDE OF THE STRONG SW/NE
ORIENTED JET STREAK. TEMPERATURES WILL BE COOLER WEST OF THE
LARAMIE RANGE FOR TUESDAY WHILE EASTERN PLAINS WILL REMAIN WARM.
BY WEDNESDAY...THE NEXT CYCLONICALLY CURVED JET STREAK WILL NOSE
INTO COLORADO PLACING THE FAVORABLE LFQ OVER THE CWA. THIS WILL
COMBINE WITH A SURFACE COLD FRONT THAT WILL DROP SOUTH THROUGH THE
AREA DURING THE DAY. BEHIND THE FRONT...UPSLOPE FLOW ALONG WITH
THE LAGGING MID-LEVEL FRONTOGENESIS WILL COMBINE WITH OVERRUNNING
MOISTURE AND THE AFOREMENTIONED LFQ TO BEGIN TO PRODUCE MORE
WIDESPREAD PRECIPITATION ESPECIALLY DURING THE AFTERNOON HOURS.
FORTUNATELY...TEMPERATURES WILL BE WARM ENOUGH FOR PRECIPITATION
TO REMAIN ALL RAIN AT THIS POINT. THIS CHANGES IN SUBSEQUENT
PERIODS IN THE LONG TERM HOWEVER. UNSETTLED WEATHER ALONG WITH
COOLER AIR...WILL HOLD TEMPERATURES DOWN ON WEDNESDAY...WITH 40S
FOR NORTHERN AND WESTERN ZONES...AND 50S ELSEWHERE.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...
MODELS CONTINUE TO HONE IN ON THE WED NIGHT PERIOD AS A
FAVORABLE TIME FOR WIDESPREAD PRECIP OVER THE CWA. THE GFS AND
ECMWF BOTH SHOW A STRONG SHORTWAVE MOVING OVER NORTHERN COLORADO ON
WED NIGHT WITH MOST OF THE CWA IN THE LEFT EXIT REGION OF THE 250MB
JET BETWEEN 00-12Z THURS. THICKNESSES AND SOUNDINGS SUGGEST THAT
SNOW WILL BE THE PRECIP TYPE ON WED NIGHT. PRECIP COULD START OUT
INITIALLY AS A MIX OF RAIN AND SNOW IN THE NEBRASKA PANHANDLE ON WED
EVENING...THEN TRANSITION QUICKLY TO SNOW AS COLD AIR ADVECTION
CONTINUES THROUGH THE EARLY NIGHT HOURS. MODEL QPF CONSENSUS IS IN
THE 0.25-0.50 INCH RANGE FOR THIS FIRST WAVE. SHORTWAVE AND ITS
ASSOCIATED DEEP LAYER LIFT MOVES EAST OF THE REGION ON THURS MORNING
WITH SNOW RATES DROPPING OFF. THE MODELS SHOW BROAD CYCLONIC FLOW
ON THURS WITH LLVL UPSLOPE ALONG AND EAST OF THE LARAMIE RANGE.
DROPPED HIGH TEMPERATURES ON THURS INTO THE LOW-TO-MID 30S OVER THE
PLAINS WITH CLOUD COVER...UPSLOPE...AND SNOW COVER MAKING IT
DIFFICULT TO GET MUCH WARMING. ALTHOUGH UPPER LEVEL FORCING IS WEAK
ON THURS...LLVL UPSLOPE COULD BE SUFFICIENT TO GENERATE SOME WEAK
SNOW SHOWERS/FLURRIES MAINLY ALONG THE LARAMIE RANGE.
THE NEXT STRONG SHORTWAVE IN THE CYCLONIC MIDLEVEL FLOW IS PROGGED
TO TREK FROM UTAH INTO COLORADO ON THURS NIGHT. WITH DEEP LAYER
UPWARD MOTION INCREASING ON THURS NIGHT...AND LLVL UPSLOPE ALREADY
IN PLACE...WOULD EXPECT ANOTHER ROUND OF SNOW ESPECIALLY OVER THE
SOUTHERN ZONES. NEED TO CONTINUE TO MONITOR THE TRACK OF THIS
SHORTWAVE AS A SHIFT TO THE NORTH OR SOUTH WOULD OBVIOUSLY HAVE
IMPLICATIONS ON QPF AMOUNTS. SNOW COMES TO AN END BY MIDDAY FRI
AS THE FORCING EXITS THE AREA. ANOTHER COLD DAY ON FRI WITH
TEMPERATURES AROUND 25-30 DEGREES BELOW NORMAL FOR LATE OCTOBER.
NORTHWESTERLY MIDLEVEL FLOW BECOMES ESTABLISHED OVER SOUTHEAST
WYOMING ON SAT WITH DRYING IN LOW AND MIDLEVELS. NOT GOING TO SEE
ANY BIG WARMUP UNTIL SUN...WHEN THE SFC HIGH PRESSURE OVER THE
PLAINS IS REPLACED BY A DEVELOPING SFC TROUGH AND INCREASINGLY ZONAL
FLOW ALOFT.
&&
.AVIATION...06Z TAF ISSUANCE. VFR CONDITIONS ACROSS SOUTHEAST
WYOMING TONIGHT. FOR WESTERN NEBRASKA TERMINALS...CURRENT
SATELLITE LOOP SHOWS STRATUS DEVELOPING AND MOVING WEST INTO KAIA
AND KCDR. EXPECT IFR CONDITIONS FROM KCDR KSNY AND KBFF TONIGHT
AND THROUGH MID MONDAY MORNING FOR CIGS BELOW 1K FEET AGL AND VIS
BETWEEN 2 TO 4 MILES...AND MAYBE EVEN BELOW A MILE AT KSNY AND
KAIA BY SUNRISE. FOG AND LOW STRATUS WILL LIFT BY MIDDAY MONDAY
WITH VERY GUSTY WINDS DEVELOPING WEST OF THE LARAMIE RANGE ACROSS
SOUTHEAST WYOMING.
&&
.FIRE WEATHER...
A FAIRLY ACTIVE WEEK TAKING SHAPE ACROSS THE DISTRICT WITH BREEZY
TO LOCALLY WINDY CONDITIONS FOR AREAS ALONG AND WEST OF THE
LARAMIE RANGE FOR MONDAY AND TUESDAY FOLLOWED BY A PROLONGED
PRECIPITATION EVENT THAT WILL BEGIN AS EARLY AS WEDNESDAY
AFTERNOON AND CONTINUE INTO FRIDAY. IF CURRENT FORECASTS HOLD THIS
WILL BRING IN MUCH COLDER AIR ALONG WITH LIGHT TO MODERATE SNOW
ACCUMULATIONS. BEFORE THEN...TEMPERATURES WILL CONTINUE TO BE
UNSEASONABLY WARM TODAY AND TUESDAY WITH HIGHS THAT WILL CLIMB
INTO THE 60S AND 70S. WINDS MAY BECOME VERY STRONG ACROSS WIND
PRONE AREAS NEAR ARLINGTON AND BORDEAUX TONIGHT WITH WIND GUSTS TO
60 MPH POSSIBLE. MINIMUM RELATIVE HUMIDITIES SHOULD HOLD IN THE
20S AND 30S FOR BOTH TODAY AND TUESDAY. HOWEVER...THESE WILL
INCREASE AS COLDER UNSETTLED CONDITIONS WORK IN FOR THE LATTER
HALF OF THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM 9 PM MONDAY TO 9 AM TUESDAY FOR WYZ106-
WYZ110.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...HAHN
LONG TERM...FINCH
AVIATION...TT
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
320 PM EDT MON OCT 22 2012
.SHORT TERM...
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.
&&
.AVIATION...
RADAR SHOWING LINE OF CONVECTION NEARING KSBN AT ISSUANCE AND WILL
BE INTO KFWA BY 20Z. HAVE TRIED TO TIME THIS LINE THROUGH TAF SITES
THROUGH LATE AFTERNOON. MCV WILL LIFT NORTH AND EXPECT SUBSIDENCE IN
WAKE TO END PCPN FOR A PERIOD THIS EVENING. DIFFICULT FORECAST
REMAINDER OF EVENING AND OVERNIGHT AS WARM FRONT WILL BE JUST NORTH
OF TAF SITES AND MODELS INDICATING ADDITIONAL CONVECTION COULD FIRE
AND MOVE EAST ALONG BOUNDARY. BETTER CHANCE FOR MORE RAIN COMES
TOWARD DAYBREAK AND INTO THE DAY TUESDAY WITH SECOND POTENT SHORT
WAVE LIFTING NORTH THROUGH OK THIS AFTERNOON. FOR NOW HAVE TRENDED
TAFS DOWN TO MVFR FOR CIGS AND VIS OVERNIGHT. SOME IFR POSSIBLE WITH
RESIDUAL LOW LEVEL MOISTURE AND UPSTREAM TRENDS THIS AFTERNOON BUT
OPTED TO KEEP OUT OF FORECAST WITH THIS PACKAGE. RAIN SHOULD BEGIN
TO TAPER OFF AT TAF SITES DURING AFTERNOON TUESDAY JUST BEYOND THIS
VALID PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1250 PM CDT MON OCT 22 2012
.UPDATE...
CONVECTION ASSOCIATED WITH THE H5 S/W THAT MOVED THROUGH THE AREA
THIS MORNING IS JUST ABOUT OUT OF THE NORTHERN CWFA AS OF NOON.
THAT MAY BE THE END OF ANY SIGNIFICANT PRECIPITATION AT LEAST
THROUGH EARLY THIS EVENING. THE WARM FRONT WAS LOCATED ROUGHLY
JUST SOUTH OF I80 AND WAS ASSOCIATED WITH A NARROW E-W ORIENTED
BAND OF STRATUS. HOLES IN THE CLOUDS HAVE OPENED UP NORTH OF THE
BOUNDARY OVER EAST CENTRAL IA AN OVER NORTHERN MO/FAR SOUTHERN IA
IN THE WARM SECTOR. NAM AND RUC SOLUTIONS ARE SHOWING SOME LIGHT
PRECIP OVER THE AREA THIS AFTERNOON BUT THAT MAY BE AN ARTIFACT OF
MOISTURE LADEN LOW LEVELS. MODEL SOUNDS SHOWED A SIGNIFICANT WARM
LAYER WITH THE INVERSION BASED AROUND H8 THROUGH MOST OF THE
AFTERNOON WHICH SHOULD KEEP THE LOW LEVEL CAPPED. HAVE KEPT SOME
LOW POPS GOING FOR THE AFTERNOON. CAPES SHOULD INCREASE TO
1000J/KG PLUS SOUTH OF THE BOUNDARY BY LATE AFTERNOON SO MENTION
TSRA THERE AND JUST SHRA NORTH OF THE BOUNDARY. MAX TEMPS WILL
HAVE TO BE ADJUSTED THIS AFTERNOON MAINLY ALONG THE WARM FRONT
WHERE THE STRATUS WILL LIMIT HIGHS FURTHER NORTH WHERE BREAKS IN
THE CLOUDS WILL ALLOW PARTS OF EAST CENTRAL IA TO WARM MORE THAN
EXPECTED.
&&
.AVIATION...
A WARM FRONT WAS LOCATED JUST SOUTH OF I80 IN EASTERN IA AND WEST
CENTRAL IL LATE THE THIS MORNING. THE FRONT IS EXPECTED TO LIFT
NORTH MOVING THROUGH THE HIGHWAY 20 CORRIDOR BY LATE TONIGHT. AS
OF LATE MORNING IFR CONDITIONS WERE OCCURRING ALONG AND SOUTH OF
THE FRONT WITH MVFR OR BETTER CONDITIONS NORTH OF BOUNDARY. WITH
THE BOUNDARY LIFTING NORTH CONDITIONS WILL DETERIORATE FROM EAST
CENTRAL IA INTO NORTHWEST IL LATE THIS AFTERNOON AND THIS EVENING
WITH AT LEAST CIGS IMPROVING SOME FROM SOUTHEAST IOWA INTO WEST
CENTRAL IL. WITH THE LOW LEVELS LOADED WITH MOISTURE THROUGH
TUESDAY MORNING EXPECT TO SEE SOME FOG THROUGH THE PERIOD WITH THE
LOWEST VSBYS OCCURRING NEAR THE WARM FRONT. HAVE NOT MENTIONED ANY
PRECIP IN THE TAFS SINCE THERE IS SUFFICIENT UNCERTAINTY COVERAGE
IF ANY PRECIP DEVELOPS AT ALL.
DLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
309 PM CDT MON OCT 22 2012
...UPDATED FOR THE LONG TERM...
.SYNOPSIS...
ISSUED AT 1242 PM CDT MON OCT 22 2012
THIS MORNING`S 12 UTC OBJECTIVE UPPER AIR ANALYSIS INDICATED A BROAD
UPPER RIDGE OVER THE CONTINENTAL U.S., MARKED BY A STRONG 100 KNOT
JET STREAK EXITING THE NORTHERN ROCKIES INTO SOUTHERN CANADA. A
SHARP TROUGH AXIS WAS LOCATED JUST OFF THE WEST COAST, WHILE
REMNANT ENERGY OF HURRICANE PAUL EVIDENT IN THE 500-300MB LAYER
WAS SPREADING ACROSS THE TEXAS PANHANDLE.
A MOIST BOUNDARY LAYER WAS EVIDENT NEAR THE SURFACE. A SURFACE
STATIONARY FRONT HAD DEVELOPED FROM NEAR MANHATTAN TO WOODWARD, OK
AND TO JUST NORTH OF AMARILLO. WIDESPREAD LOW STRATUS HAD DEVELOPED
ALONG AND NORTH OF THE BOUNDARY AS A COOLER AIRMASS FROM THE
NORTHERN HALF OF THE CENTRAL PLAINS HAD SETTLED IN OVER WESTERN
KANSAS ON LIGHT NORTH WINDS. DENSE FOG DEVELOPED IN THE
CONVERGENCE ZONE EARLIER IN THE MORNING, BUT HAD BEGUN TO IMPROVE
SIGNIFICANTLY AFTER 15 UTC THIS MORNING. A VERY SHALLOW SURFACE
MOIST LAYER WAS EVIDENT ON THE 12 UTC KDDC SOUNDING.
&&
.UPDATE...
ISSUED AT 1242 PM CDT MON OCT 22 2012
TEMPERATURES WERE TRIMMED DRAMATICALLY (HEDGED TOWARD THE 16Z RAPID
REFRESH FORECAST) FOR THE AFTERNOON AS THE LOW STRATUS HAS HELD IN
PLACE ACROSS A LARGE PORTION OF WESTERN KANSAS THROUGH THE ENTIRE
MORNING. THIS DID APPEAR REASONABLE ON 12 UTC NAM FORECAST
SOUNDINGS AS THE MOIST DEPTH APPEARED TO WORK AGAINST THE
INSOLATION IN THE LATE MORNING. THE RELATIVE SHALLOW NATURE OF THE
STRATUS DECK STILL SUGGESTS SUN EROSION OF THE LAYER AS THE
AFTERNOON PROGRESSES, AND MORE SUN BY AT LEAST MID AFTERNOON.
HOWEVER, THE PEAK HEATING PERIOD MAY COME AND GO FOR WARMING
ANYWHERE NEAR THE EARLIER EXPECTED HIGHS. THE FORECAST WILL
CONTINUE TO BE COOL BIASED IN THE VERY NEAR TERM.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 321 AM CDT MON OCT 22 2012
COMPLICATED FORECAST TODAY WITH HIGH TEMPERATURE BUST POTENTIAL,
PARTICULARLY ALONG INTERSTATE 70. LOW STRATUS IS BEGINNING TO INCREASE
IN AERIAL COVERAGE PER THE 11U-3.9U SATELLITE CHANNEL AND KHYS IS ALREADY
IN THE LOW STRATUS/IFR CONDITIONS. FOR THE TEMPERATURE FORECAST, WILL
PUT MORE OF AN EMPHASIS ON THE 00Z NAM/ARW-NMM MESOSCALE MODELS WHICH
KEEPS CENTRAL KANSAS UNDER STRATUS AND RESULTANT COOLER TEMPERATURES.
THE ARW-NMM IS VERY AGGRESSIVE WITH COOLER TEMPERATURES AND KEEPS KHYS
IN THE 50S DEG F. THE NAM SUGGESTS MID 60S DEG F. WILL COMPROMISE BETWEEN
THE PREVIOUS FORECAST AND THE NEW 00Z DATA AND KEEP TEMPERATURES AROUND
70 DEG F ACROSS WEST CENTRAL AND CENTRAL KANSAS. THERE IS LARGE UNCERTAINTY
ON HOW LONG THE STRATUS WILL STICK AROUND AS ISENTROPIC DOWNGLIDE IS
EVENTUALLY FORECAST. WILL ALSO KEEP PATCHY FOG IN THE WX GRIDS GENERALLY
EAST OF HIGHWAY 283 THIS MORNING. HRRR SUGGESTS DENSE FOG THIS MORNING
BUT WILL GO WITH PATCHY FOR NOW AS CURRENT OBSERVATIONS SHOW THAT THE
HRRR MODEL IS BEING A BIT AGGRESSIVE ON FORECAST VISIBILITIES FOR THE
CURRENT HOUR. THERE ALSO COULD BE SOME DRIZZLE ALONG I-70 BUT NOT SURE
OF THE SATURATED LAYER WILL BE THICK ENOUGH AS BUFR SOUNDINGS ARE AROUND
2000 FEET INSTEAD OF THE 3000 FEET IDEAL THICKNESS. THE WARMEST TEMPERATURES
ARE EXPECTED ALONG THE FRONTAL BOUNDARY ACROSS SOUTH CENTRAL KANSAS
WHERE 80S DEG ARE LIKELY AS A NARROW WEDGE OF WARMER 850 HPA TEMPERATURES
/DOWNSLOPE WINDS ARE FORECAST.
BY THIS EVENING, THE AFOREMENTIONED BOUNDARY WILL RETURN NORTHWARD AS
A WARM FRONT. WILL GO WITH WARMER MINIMUM TEMPERATURES ACROSS SOUTH
CENTRAL KANSAS AS FAIRLY HIGH SURFACE DEWPOINTS ADVECT NORTHWARD AGAIN.
PATCHY FOG LOOKS POSSIBLE AGAIN TOMORROW MORNING VIA BUFR SOUNDINGS
/MOS GUIDANCE/ AND BOUNDARY LAYER RELATIVE HUMIDITY PROGS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 305 PM CDT MON OCT 22 2012
THE MAIN CONCERN IN THE EXTENDED IS REALLY THE COLD SNAP SATURDAY
AND SUNDAY MORNINGS. IN THE NEARER TERM, WEDNESDAY LOOKS TO BE VERY
WARM WITH THE BORDER COUNTIES ALONG OKLAHOMA REACHING THE MID TO
UPPER 80S, WITH THE LOW END OF THE MID 80S FROM THE SYRACUSE TO HAYS
AREAS. SINCE WINDS WILL BE PICKING UP IN THE AFTERNOON WEDNESDAY AS
THE TEMPERATURE GRADIENT MERGES WITH THE PRESSURE GRADIENT, THE
RELATIVE HUMIDITY VALUES SHOULD DIP AND DRY OUT DURING THE EARLY
AFTERNOON INTO THE 16-17 PERCENT RANGE. THEREFORE, HAVE ISSUED A
FIRE WEATHER WATCH FROM 18Z TO 00Z WEDNESDAY AFTERNOON AND EVENING,
WITH THE SURFACE RH BEING MARGINAL. THERE IS A SIGNIFICANT COLD
FRONT COMING THROUGH TOWARD THE SOUTH WEDNESDAY NIGHT. THIS FRONT
WILL EFFECTIVELY LOWER THE MAXIMUM TEMPERATURES THURSDAY SOME 20 TO
30 DEGREES FROM THE DAY BEFORE (WED). HIGHS ON THURSDAY WILL VARY
FROM THE LOWER 50S IN OUR NORTH NEAR SYRACUSE, SCOTT CITY AND
WAKEENEY TO THE MID 60S IN THE COLDWATER AND MEDICINE LODGE AREAS.
MINIMUM TEMPERATURES WILL START THE DOWN HILL TREND THURSDAY
MORNING, WITH A SLIM AREA NORTHWEST OF A LINE FROM SCOTT CITY TO
JOHNSON CITY FALLING TO THE MID 30S, WITH THE STAFFORD, PRATT AND
BARBER COUNTIES ONLY COOLING TO THE MID 50S. COLD AIR WILL DROP
THROUGH THE PLAINS AND SPILL INTO THE THE SOUTHERN PLAINS THURSDAY
AND FRIDAY. FRIDAY MAY ONLY REACH THE MID 40S FOR HIGHS IN OUR WEST
AND NORTHWEST, WITH THE SOUTHEAST AREAS NEAR MEDICINE LODGE JUST
REACHING AROUND 50F DEGREES. A BROAD SCALE UPPER TROUGH WILL MOVE
WEST TO EAST ON FRIDAY, AND SMALL 17 TO 23 PERCENT POPS WERE PUT IN
FOR FRIDAY AND FRIDAY NIGHT BY THE CREXTENDFCST PROCEDURE. HAVE
DECIDED TO LOWER
THESE SLIGHT POPS TO 14 TO 17 PERCENT, AND GO WITH A PRECIPITATION
TYPE AS RAIN SHOWERS WITH ISOLATED THUNDERSTORMS. HAVE MY DOUBTS IF
WE WILL GET ANYTHING MORE THAN SPRINKLES, SINCE A SURFACE HIGH
PRESSURE RIDGE WILL BE OVER US.
LOWS SATURDAY AND SUNDAY MORNINGS WILL LIKELY BRING A HARD FREEZE TO
TO PARTS OF OUR CWA, BUT NOT ALL. FOR THOSE AREAS WHICH HAVE NOT
HAD A HARD FREEZE (28F), THERE SHOULD BE AN AREA OF OUR NORTHWEST
AND WESTERN CWA WHICH WILL SEE THEIR FIRST HARD FREEZE, WITH LOWS IN
THE 26-28F DEGREE RANGE. IT MAY COME FRIDAY NIGHT IN SOME AREAS AND
ON SATURDAY NIGHT IN OTHER LOCAL AREAS. AT THIS TIME, THOSE AREAS
SOUTHEAST OF A STAFFORD COUNTY TO MEADE COUNTY LINE MAY SEE SOME
FROST WITH TEMPERATURES IN THE LOWER 30S, BUT A HARD FREEZE IS NOT
EXPECTED THERE. SATURDAY WILL BE COOL SIMILAR TO FRIDAY, WITH HIGHS
IN THE MID 40S TO AROUND 50F. WITH MOSTLY SUNNY SKIES SUNDAY AND
MONDAY, AFTERNOON TEMPERATURES WILL WARM INTO THE MID 50S TO LOWER
60S BY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1259 PM CDT MON OCT 22 2012
IFR STRATUS HELD ACROSS A LARGER PORTION OF THE TAF AREA FOR LONER
THAN INITIAL ANTICIPATED, AND IS STILL EXPECTED TO BE A PROBLEM AT
LEAST THROUGH THE EARLY AFTERNOON NEAR THE DODGE CITY AND GARDEN CITY
AIRPORTS. THE LAYER IS QUITE SHALLOW, AND HAS THE POTENTIAL TO ERODE
VERY QUICKLY, BUT HAS LASTED LONGER THAN FORECAST MODEL SOUNDINGS
INDICATED. WITH THIS REASON WE WILL FORECAST THE STRATUS TO LAST
LONGER INTO THE AFTERNOON, WHICH GFS LAMP MOS GUIDANCE SUPPORTS, BUT
STILL WITH HIGH FORECASTER UNCERTAINTY. A SHORTWAVE TOUGH LIFTING
NORTHWARD IS EXPECTED TO AID SURFACE PRESSURE FALL AND BRING A
RETURN TO SOUTHWEST WINDS, WHICH SHOULD CLEAR THE LOW CLOUDS OUT BY
MID TO LATE AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 88 60 85 / 0 0 0 0
GCK 47 88 56 84 / 0 0 0 0
EHA 50 86 57 86 / 0 0 0 0
LBL 48 89 55 86 / 0 0 0 0
HYS 52 88 56 83 / 0 0 0 10
P28 61 92 65 87 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR KSZ061>063-074>076-084>086.
&&
$$
UPDATE...RUSSELL
SYNOPSIS...RUSSELL
SHORT TERM...SUGDEN
LONG TERM...BURKE
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
100 PM CDT MON OCT 22 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 1242 PM CDT MON OCT 22 2012
THIS MORNING`S 12 UTC OBJECTIVE UPPER AIR ANALYSIS INDICATED A BROAD
UPPER RIDGE OVER THE CONTINENTAL U.S., MARKED BY A STRONG 100 KNOT
JET STREAK EXITING THE NORTHERN ROCKIES INTO SOUTHERN CANADA. A
SHARP TROUGH AXIS WAS LOCATED JUST OFF THE WEST COAST, WHILE
REMNANT ENERGY OF HURRICANE PAUL EVIDENT IN THE 500-300MB LAYER
WAS SPREADING ACROSS THE TEXAS PANHANDLE.
A MOIST BOUNDARY LAYER WAS EVIDENT NEAR THE SURFACE. A SURFACE
STATIONARY FRONT HAD DEVELOPED FROM NEAR MANHATTAN TO WOODWARD, OK
AND TO JUST NORTH OF AMARILLO. WIDESPREAD LOW STRATUS HAD DEVELOPED
ALONG AND NORTH OF THE BOUNDARY AS A COOLER AIRMASS FROM THE
NORTHERN HALF OF THE CENTRAL PLAINS HAD SETTLED IN OVER WESTERN
KANSAS ON LIGHT NORTH WINDS. DENSE FOG DEVELOPED IN THE
CONVERGENCE ZONE EARLIER IN THE MORNING, BUT HAD BEGUN TO IMPROVE
SIGNIFICANTLY AFTER 15 UTC THIS MORNING. A VERY SHALLOW SURFACE
MOIST LAYER WAS EVIDENT ON THE 12 UTC KDDC SOUNDING.
&&
.UPDATE...
ISSUED AT 1242 PM CDT MON OCT 22 2012
TEMPERATURES WERE TRIMMED DRAMATICALLY (HEDGED TOWARD THE 16Z RAPID
REFRESH FORECAST) FOR THE AFTERNOON AS THE LOW STRATUS HAS HELD IN
PLACE ACROSS A LARGE PORTION OF WESTERN KANSAS THROUGH THE ENTIRE
MORNING. THIS DID APPEAR REASONABLE ON 12 UTC NAM FORECAST
SOUNDINGS AS THE MOIST DEPTH APPEARED TO WORK AGAINST THE
INSOLATION IN THE LATE MORNING. THE RELATIVE SHALLOW NATURE OF THE
STRATUS DECK STILL SUGGESTS SUN EROSION OF THE LAYER AS THE
AFTERNOON PROGRESSES, AND MORE SUN BY AT LEAST MID AFTERNOON.
HOWEVER, THE PEAK HEATING PERIOD MAY COME AND GO FOR WARMING
ANYWHERE NEAR THE EARLIER EXPECTED HIGHS. THE FORECAST WILL
CONTINUE TO BE COOL BIASED IN THE VERY NEAR TERM.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 321 AM CDT MON OCT 22 2012
COMPLICATED FORECAST TODAY WITH HIGH TEMPERATURE BUST POTENTIAL,
PARTICULARLY ALONG INTERSTATE 70. LOW STRATUS IS BEGINNING TO INCREASE
IN AERIAL COVERAGE PER THE 11U-3.9U SATELLITE CHANNEL AND KHYS IS ALREADY
IN THE LOW STRATUS/IFR CONDITIONS. FOR THE TEMPERATURE FORECAST, WILL
PUT MORE OF AN EMPHASIS ON THE 00Z NAM/ARW-NMM MESOSCALE MODELS WHICH
KEEPS CENTRAL KANSAS UNDER STRATUS AND RESULTANT COOLER TEMPERATURES.
THE ARW-NMM IS VERY AGGRESSIVE WITH COOLER TEMPERATURES AND KEEPS KHYS
IN THE 50S DEG F. THE NAM SUGGESTS MID 60S DEG F. WILL COMPROMISE BETWEEN
THE PREVIOUS FORECAST AND THE NEW 00Z DATA AND KEEP TEMPERATURES AROUND
70 DEG F ACROSS WEST CENTRAL AND CENTRAL KANSAS. THERE IS LARGE UNCERTAINTY
ON HOW LONG THE STRATUS WILL STICK AROUND AS ISENTROPIC DOWNGLIDE IS
EVENTUALLY FORECAST. WILL ALSO KEEP PATCHY FOG IN THE WX GRIDS GENERALLY
EAST OF HIGHWAY 283 THIS MORNING. HRRR SUGGESTS DENSE FOG THIS MORNING
BUT WILL GO WITH PATCHY FOR NOW AS CURRENT OBSERVATIONS SHOW THAT THE
HRRR MODEL IS BEING A BIT AGGRESSIVE ON FORECAST VISIBILITIES FOR THE
CURRENT HOUR. THERE ALSO COULD BE SOME DRIZZLE ALONG I-70 BUT NOT SURE
OF THE SATURATED LAYER WILL BE THICK ENOUGH AS BUFR SOUNDINGS ARE AROUND
2000 FEET INSTEAD OF THE 3000 FEET IDEAL THICKNESS. THE WARMEST TEMPERATURES
ARE EXPECTED ALONG THE FRONTAL BOUNDARY ACROSS SOUTH CENTRAL KANSAS
WHERE 80S DEG ARE LIKELY AS A NARROW WEDGE OF WARMER 850 HPA TEMPERATURES
/DOWNSLOPE WINDS ARE FORECAST.
BY THIS EVENING, THE AFOREMENTIONED BOUNDARY WILL RETURN NORTHWARD AS
A WARM FRONT. WILL GO WITH WARMER MINIMUM TEMPERATURES ACROSS SOUTH
CENTRAL KANSAS AS FAIRLY HIGH SURFACE DEWPOINTS ADVECT NORTHWARD AGAIN.
PATCHY FOG LOOKS POSSIBLE AGAIN TOMORROW MORNING VIA BUFR SOUNDINGS
/MOS GUIDANCE/ AND BOUNDARY LAYER RELATIVE HUMIDITY PROGS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 AM CDT MON OCT 22 2012
MAIN CONCERNS IN THIS PERIOD ARE FIRE WEATHER CONDITIONS FOR TUESDAY
AND WEDNESDAY AFTERNOONS IN THE SOUTHWEST FA FROM NESS CITY TO DODGE
CITY AND WEST, CHANCES OF THUNDERSTORMS IN THE EAST FA FROM HAYS TO
COLDWATER AND EAST WITH A COLD FRONT FOR WEDNESDAY NIGHT INTO
THURSDAY MORNING, AND THE POSSIBILITY FOR BELOW FREEZING
TEMPERATURES FOR NEXT SATURDAY AND SUNDAY MORNINGS.
FOR TUESDAY AND WEDNESDAY SOUTHWEST AND SOUTH CENTRAL KANSAS WILL BE
IN THE WARM SECTOR AHEAD OF A STRONG UPPER LEVEL BROAD TROUGH MOVING
FROM THE WESTERN CONUS AND INTO THE ROCKIES AND 4 CORNERS REGION. A
DRYLINE IS FORECAST TO SET UP FROM WAKEENEY TO DODGE CITY AND MEADE,
THEN PROGRESS EASTWARD DURING THE AFTERNOON. THE SAME SITUATION
REPEATS ITSELF ON WEDNESDAY AFTERNOON. SURFACE LOW PRESSURE IN THE
LEE OF THE ROCKIES WILL DEEPEN INTO WEDNESDAY WITH THE STRONGEST
PRESSURE GRADIENT ON WEDNESDAY AFTERNOON. BY TUESDAY AFTERNOON THE
SOUTH TO SOUTHWEST WINDS COULD BE FROM 15 TO 25 MPH AND THEN 20 TO
30 MPH ON WEDNESDAY AFTERNOON. RELATIVE HUMIDITIES SHOULD FALL BELOW
15 TO 20 PERCENT BOTH AFTERNOONS, SO WILL HAVE TO KEEP A CLOSE EYE
OUT FOR A FIRE WEATHER WATCH ESPECIALLY FOR WEDNESDAY AFTERNOON FOR
OUR SOUTHWESTERN COUNTIES. SINCE TUESDAY AFTERNOON WINDS ARE NOT AS
STRONG WILL NOT GO WITH A WATCH AT THIS TIME. AFTERNOON HIGHS SHOULD
BE IN THE MID TO UPPER 80S FOR BOTH DAYS. OVERNIGHT LOWS ARE
FORECAST TO BE VERY MILD ON TUESDAY NIGHT WITH SOUTH BREEZES AT 10
TO 20 MPH.
THEN FOR WEDNESDAY NIGHT AND THURSDAY THE BROAD UPPER LEVEL TROUGH
MOVES ACROSS THE PLAINS PUSHING A STRONG COLD FRONT ACROSS WESTERN
KANSAS. WITH GOOD MOISTURE AHEAD OF THE COLD FRONT A FEW STRONG TO
POSSIBLY SEVERE THUNDERSTORMS MAY DEVELOP ALONG AND AHEAD OF THE
COLD FRONT. THERE WILL BE PLENTY OF LAYER WIND SHEAR WITH FORECAST
CAPE AROUND 1000 J/KG. THE AREA FROM HAYS SOUTH TO GREENSBURG AND
COLDWATER AND EAST HAS THE BEST CHANCES FOR THUNDERSTORMS INTO LATE
WEDNESDAY NIGHT. NORTH WINDS OF 15 TO 25 MPH AND GUSTY WILL FOLLOW
THE FRONT THAT SHOULD BE MOVING LASTLY THROUGH MEDICINE LODGE BY 7
AM THURSDAY MORNING. THURSDAY MORNING LOWS ARE FORECAST TO RANGE
FROM THE MID 40S WEST TO THE MID 50S EAST FROM SAINT JOHN TO
MEDICINE LODGE. DAYTIME HIGHS ON THURSDAY WILL ONLY BE IN THE MID TO
UPPER 50S NORTH TO MID 60S SOUTH AS MUCH COLDER SURFACE HIGH
PRESSURE FOLLOWS THE COLD FRONT. THURSDAY NIGHT LOWS LOOK TO BE IN
THE MID TO UPPER 30S WITH SOME MIXING.
FOR FRIDAY A SECONDARY UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE
PLAINS WITH MAINLY MID AND HIGH LEVEL CLOUDINESS. THE GFS LOOKS WAY
OVER SATURATED AND IS A TYPICAL MODEL BIAS WHILE THE NEW ECMWF LOOK
VERY DRY THROUGH THE LAYER. WILL GO AHEAD AND HEDGE TOWARD THE ECMWF
AND TAKE POPS DOWN TO SILENT. A STRONG RIDGE OF SURFACE HIGH
PRESSURE WILL REINFORCE ITSELF INTO THE WESTERN HIGH PLAINS WITH
HIGHS ONLY IN THE UPPER 40S TO LOWER 50S.
FOR THE WEEKEND A VERY DRY AIRMASS IS FORECAST WITH DEWPOINTS IN THE
20`S. DAYTIME HIGHS FOR SATURDAY ARE AGAIN ONLY IN THE UPPER 40S TO
LOWER 50S THEN WARM INTO THE 50S ON SUNDAY. BY SATURDAY MORNING THE
MODELS ARE FORECASTING A SHARP RIDGE AXIS OF HIGH PRESSURE WITH
LIGHT WINDS AND CLEAR SKIES. ON SUNDAY MORNING THE GFS HAS THE RIDGE
MOVING EAST INTO CENTRAL KANSAS WHILE THE ECMWF HAS IT AGAIN OVER
SOUTHWEST KANSAS. IF THE MODELS ARE CORRECT THERE IS A GOOD
POSSIBILITY OF A FREEZE OR KILLING FREEZE ON BOTH EARLY MORNINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1259 PM CDT MON OCT 22 2012
IFR STRATUS HELD ACROSS A LARGER PORTION OF THE TAF AREA FOR LONER
THAN INITIAL ANTICIPATED, AND IS STILL EXPECTED TO BE A PROBLEM AT
LEAST THROUGH THE EARLY AFTERNOON NEAR THE DODGE CITY AND GARDEN CITY
AIRPORTS. THE LAYER IS QUITE SHALLOW, AND HAS THE POTENTIAL TO ERODE
VERY QUICKLY, BUT HAS LASTED LONGER THAN FORECAST MODEL SOUNDINGS
INDICATED. WITH THIS REASON WE WILL FORECAST THE STRATUS TO LAST
LONGER INTO THE AFTERNOON, WHICH GFS LAMP MOS GUIDANCE SUPPORTS, BUT
STILL WITH HIGH FORECASTER UNCERTAINTY. A SHORTWAVE TOUGH LIFTING
NORTHWARD IS EXPECTED TO AID SURFACE PRESSURE FALL AND BRING A
RETURN TO SOUTHWEST WINDS, WHICH SHOULD CLEAR THE LOW CLOUDS OUT BY
MID TO LATE AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 52 87 60 / 0 0 0 0
GCK 62 47 87 56 / 0 0 0 0
EHA 71 50 87 57 / 0 0 0 0
LBL 68 48 88 55 / 0 0 0 0
HYS 63 52 85 56 / 0 0 0 0
P28 84 61 90 65 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RUSSELL
SYNOPSIS...RUSSELL
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1246 PM CDT MON OCT 22 2012
...UPDATED FOR TRENDS...
.SYNOPSIS...
ISSUED AT 1242 PM CDT MON OCT 22 2012
THIS MORNING`S 12 UTC OBJECTIVE UPPER AIR ANALYSIS INDICATED A BROAD
UPPER RIDGE OVER THE CONTINENTAL U.S., MARKED BY A STRONG 100 KNOT
JET STREAK EXITING THE NORTHERN ROCKIES INTO SOUTHERN CANADA. A
SHARP TROUGH AXIS WAS LOCATED JUST OFF THE WEST COAST, WHILE
REMNANT ENERGY OF HURRICANE PAUL EVIDENT IN THE 500-300MB LAYER
WAS SPREADING ACROSS THE TEXAS PANHANDLE.
A MOIST BOUNDARY LAYER WAS EVIDENT NEAR THE SURFACE. A SURFACE
STATIONARY FRONT HAD DEVELOPED FROM NEAR MANHATTAN TO WOODWARD, OK
AND TO JUST NORTH OF AMARILLO. WIDESPREAD LOW STRATUS HAD DEVELOPED
ALONG AND NORTH OF THE BOUNDARY AS A COOLER AIRMASS FROM THE
NORTHERN HALF OF THE CENTRAL PLAINS HAD SETTLED IN OVER WESTERN
KANSAS ON LIGHT NORTH WINDS. DENSE FOG DEVELOPED IN THE
CONVERGENCE ZONE EARLIER IN THE MORNING, BUT HAD BEGUN TO IMPROVE
SIGNIFICANTLY AFTER 15 UTC THIS MORNING. A VERY SHALLOW SURFACE
MOIST LAYER WAS EVIDENT ON THE 12 UTC KDDC SOUNDING.
&&
.UPDATE...
ISSUED AT 1242 PM CDT MON OCT 22 2012
TEMPERATURES WERE TRIMMED DRAMATICALLY (HEDGED TOWARD THE 16Z RAPID
REFRESH FORECAST) FOR THE AFTERNOON AS THE LOW STRATUS HAS HELD IN
PLACE ACROSS A LARGE PORTION OF WESTERN KANSAS THROUGH THE ENTIRE
MORNING. THIS DID APPEAR REASONABLE ON 12 UTC NAM FORECAST
SOUNDINGS AS THE MOIST DEPTH APPEARED TO WORK AGAINST THE
INSOLATION IN THE LATE MORNING. THE RELATIVE SHALLOW NATURE OF THE
STRATUS DECK STILL SUGGESTS SUN EROSION OF THE LAYER AS THE
AFTERNOON PROGRESSES, AND MORE SUN BY AT LEAST MID AFTERNOON.
HOWEVER, THE PEAK HEATING PERIOD MAY COME AND GO FOR WARMING
ANYWHERE NEAR THE EARLIER EXPECTED HIGHS. THE FORECAST WILL
CONTINUE TO BE COOL BIASED IN THE VERY NEAR TERM.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 321 AM CDT MON OCT 22 2012
COMPLICATED FORECAST TODAY WITH HIGH TEMPERATURE BUST POTENTIAL,
PARTICULARLY ALONG INTERSTATE 70. LOW STRATUS IS BEGINNING TO INCREASE
IN AERIAL COVERAGE PER THE 11U-3.9U SATELLITE CHANNEL AND KHYS IS ALREADY
IN THE LOW STRATUS/IFR CONDITIONS. FOR THE TEMPERATURE FORECAST, WILL
PUT MORE OF AN EMPHASIS ON THE 00Z NAM/ARW-NMM MESOSCALE MODELS WHICH
KEEPS CENTRAL KANSAS UNDER STRATUS AND RESULTANT COOLER TEMPERATURES.
THE ARW-NMM IS VERY AGGRESSIVE WITH COOLER TEMPERATURES AND KEEPS KHYS
IN THE 50S DEG F. THE NAM SUGGESTS MID 60S DEG F. WILL COMPROMISE BETWEEN
THE PREVIOUS FORECAST AND THE NEW 00Z DATA AND KEEP TEMPERATURES AROUND
70 DEG F ACROSS WEST CENTRAL AND CENTRAL KANSAS. THERE IS LARGE UNCERTAINTY
ON HOW LONG THE STRATUS WILL STICK AROUND AS ISENTROPIC DOWNGLIDE IS
EVENTUALLY FORECAST. WILL ALSO KEEP PATCHY FOG IN THE WX GRIDS GENERALLY
EAST OF HIGHWAY 283 THIS MORNING. HRRR SUGGESTS DENSE FOG THIS MORNING
BUT WILL GO WITH PATCHY FOR NOW AS CURRENT OBSERVATIONS SHOW THAT THE
HRRR MODEL IS BEING A BIT AGGRESSIVE ON FORECAST VISIBILITIES FOR THE
CURRENT HOUR. THERE ALSO COULD BE SOME DRIZZLE ALONG I-70 BUT NOT SURE
OF THE SATURATED LAYER WILL BE THICK ENOUGH AS BUFR SOUNDINGS ARE AROUND
2000 FEET INSTEAD OF THE 3000 FEET IDEAL THICKNESS. THE WARMEST TEMPERATURES
ARE EXPECTED ALONG THE FRONTAL BOUNDARY ACROSS SOUTH CENTRAL KANSAS
WHERE 80S DEG ARE LIKELY AS A NARROW WEDGE OF WARMER 850 HPA TEMPERATURES
/DOWNSLOPE WINDS ARE FORECAST.
BY THIS EVENING, THE AFOREMENTIONED BOUNDARY WILL RETURN NORTHWARD AS
A WARM FRONT. WILL GO WITH WARMER MINIMUM TEMPERATURES ACROSS SOUTH
CENTRAL KANSAS AS FAIRLY HIGH SURFACE DEWPOINTS ADVECT NORTHWARD AGAIN.
PATCHY FOG LOOKS POSSIBLE AGAIN TOMORROW MORNING VIA BUFR SOUNDINGS
/MOS GUIDANCE/ AND BOUNDARY LAYER RELATIVE HUMIDITY PROGS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 355 AM CDT MON OCT 22 2012
MAIN CONCERNS IN THIS PERIOD ARE FIRE WEATHER CONDITIONS FOR TUESDAY
AND WEDNESDAY AFTERNOONS IN THE SOUTHWEST FA FROM NESS CITY TO DODGE
CITY AND WEST, CHANCES OF THUNDERSTORMS IN THE EAST FA FROM HAYS TO
COLDWATER AND EAST WITH A COLD FRONT FOR WEDNESDAY NIGHT INTO
THURSDAY MORNING, AND THE POSSIBILITY FOR BELOW FREEZING
TEMPERATURES FOR NEXT SATURDAY AND SUNDAY MORNINGS.
FOR TUESDAY AND WEDNESDAY SOUTHWEST AND SOUTH CENTRAL KANSAS WILL BE
IN THE WARM SECTOR AHEAD OF A STRONG UPPER LEVEL BROAD TROUGH MOVING
FROM THE WESTERN CONUS AND INTO THE ROCKIES AND 4 CORNERS REGION. A
DRYLINE IS FORECAST TO SET UP FROM WAKEENEY TO DODGE CITY AND MEADE,
THEN PROGRESS EASTWARD DURING THE AFTERNOON. THE SAME SITUATION
REPEATS ITSELF ON WEDNESDAY AFTERNOON. SURFACE LOW PRESSURE IN THE
LEE OF THE ROCKIES WILL DEEPEN INTO WEDNESDAY WITH THE STRONGEST
PRESSURE GRADIENT ON WEDNESDAY AFTERNOON. BY TUESDAY AFTERNOON THE
SOUTH TO SOUTHWEST WINDS COULD BE FROM 15 TO 25 MPH AND THEN 20 TO
30 MPH ON WEDNESDAY AFTERNOON. RELATIVE HUMIDITIES SHOULD FALL BELOW
15 TO 20 PERCENT BOTH AFTERNOONS, SO WILL HAVE TO KEEP A CLOSE EYE
OUT FOR A FIRE WEATHER WATCH ESPECIALLY FOR WEDNESDAY AFTERNOON FOR
OUR SOUTHWESTERN COUNTIES. SINCE TUESDAY AFTERNOON WINDS ARE NOT AS
STRONG WILL NOT GO WITH A WATCH AT THIS TIME. AFTERNOON HIGHS SHOULD
BE IN THE MID TO UPPER 80S FOR BOTH DAYS. OVERNIGHT LOWS ARE
FORECAST TO BE VERY MILD ON TUESDAY NIGHT WITH SOUTH BREEZES AT 10
TO 20 MPH.
THEN FOR WEDNESDAY NIGHT AND THURSDAY THE BROAD UPPER LEVEL TROUGH
MOVES ACROSS THE PLAINS PUSHING A STRONG COLD FRONT ACROSS WESTERN
KANSAS. WITH GOOD MOISTURE AHEAD OF THE COLD FRONT A FEW STRONG TO
POSSIBLY SEVERE THUNDERSTORMS MAY DEVELOP ALONG AND AHEAD OF THE
COLD FRONT. THERE WILL BE PLENTY OF LAYER WIND SHEAR WITH FORECAST
CAPE AROUND 1000 J/KG. THE AREA FROM HAYS SOUTH TO GREENSBURG AND
COLDWATER AND EAST HAS THE BEST CHANCES FOR THUNDERSTORMS INTO LATE
WEDNESDAY NIGHT. NORTH WINDS OF 15 TO 25 MPH AND GUSTY WILL FOLLOW
THE FRONT THAT SHOULD BE MOVING LASTLY THROUGH MEDICINE LODGE BY 7
AM THURSDAY MORNING. THURSDAY MORNING LOWS ARE FORECAST TO RANGE
FROM THE MID 40S WEST TO THE MID 50S EAST FROM SAINT JOHN TO
MEDICINE LODGE. DAYTIME HIGHS ON THURSDAY WILL ONLY BE IN THE MID TO
UPPER 50S NORTH TO MID 60S SOUTH AS MUCH COLDER SURFACE HIGH
PRESSURE FOLLOWS THE COLD FRONT. THURSDAY NIGHT LOWS LOOK TO BE IN
THE MID TO UPPER 30S WITH SOME MIXING.
FOR FRIDAY A SECONDARY UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE
PLAINS WITH MAINLY MID AND HIGH LEVEL CLOUDINESS. THE GFS LOOKS WAY
OVER SATURATED AND IS A TYPICAL MODEL BIAS WHILE THE NEW ECMWF LOOK
VERY DRY THROUGH THE LAYER. WILL GO AHEAD AND HEDGE TOWARD THE ECMWF
AND TAKE POPS DOWN TO SILENT. A STRONG RIDGE OF SURFACE HIGH
PRESSURE WILL REINFORCE ITSELF INTO THE WESTERN HIGH PLAINS WITH
HIGHS ONLY IN THE UPPER 40S TO LOWER 50S.
FOR THE WEEKEND A VERY DRY AIRMASS IS FORECAST WITH DEWPOINTS IN THE
20`S. DAYTIME HIGHS FOR SATURDAY ARE AGAIN ONLY IN THE UPPER 40S TO
LOWER 50S THEN WARM INTO THE 50S ON SUNDAY. BY SATURDAY MORNING THE
MODELS ARE FORECASTING A SHARP RIDGE AXIS OF HIGH PRESSURE WITH
LIGHT WINDS AND CLEAR SKIES. ON SUNDAY MORNING THE GFS HAS THE RIDGE
MOVING EAST INTO CENTRAL KANSAS WHILE THE ECMWF HAS IT AGAIN OVER
SOUTHWEST KANSAS. IF THE MODELS ARE CORRECT THERE IS A GOOD
POSSIBILITY OF A FREEZE OR KILLING FREEZE ON BOTH EARLY MORNINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 559 AM CDT MON OCT 22 2012
A COLD FRONT WILL CONTINUE TO MOVE ACROSS WESTERN KANSAS TODAY
WITH LIGHT NORTH TO NORTHWEST WINDS. SOME IFR CONDITIONS ARE
FORECAST WITH LOW STRATUS AND FOG THROUGH 14Z AT KDDC AND KGCK AND
AND MAINLY LOW CIGS THROUGH 06Z AT KHYS. AN UPPER LEVEL SHORTWAVE
TROUGH WILL THEN BRING SOME MID AND HIGH CLOUDINESS THROUGH MID TO
LATE AFTERNOON, THEN LOOK FOR CLEARING SKIES. AS LOW PRESSURE
DEEPENS IN EASTERN COLORADO TONIGHT, LIGHT EAST TO SOUTHEASTERLY
WINDS BECOME SOUTH TO SOUTHWEST WITH A RETURNING WARM FROM AFTER
06Z TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 52 87 60 / 0 0 0 0
GCK 62 47 87 56 / 0 0 0 0
EHA 71 50 87 57 / 0 0 0 0
LBL 68 48 88 55 / 0 0 0 0
HYS 63 52 85 56 / 0 0 0 0
P28 84 61 90 65 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RUSSELL
SYNOPSIS...RUSSELL
SHORT TERM...SUGDEN
LONG TERM...KRUSE
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1035 AM MDT MON OCT 22 2012
.SHORT TERM...VALID FOR TDY AND TUE...
THE PRECIPITATION BLOSSOMING AROUND POCATELLO ID AT 16 UTC IS TIED
TO A RATHER VIGOROUS MID-LEVEL SHORT WAVE TROUGH THAT WE EXPECT TO
AFFECT SOUTH CENTRAL MT THIS AFTERNOON AND EVENING. UTILIZING SOME
SIMPLE EXTRAPOLATION TAKES THIS MOISTURE INTO LIVINGSTON BY AROUND
19 UTC...WHICH PROVIDES STRONG CREDENCE TO THE 12 UTC NAM...GFS...
AND HRRR GUIDANCE. THOSE SOLUTIONS ALL SHOW A RATHER ROBUST SHIELD
OF PRECIPITATION FROM GARDINER AND COOKE CITY UP TO LIVINGSTON AND
HARLOWTON BETWEEN 18 AND 03 UTC THANKS TO FORCING FROM THE 700- TO
500-HPA SHORT WAVE TROUGH AND SOME MID-LEVEL FRONTOGENESIS. WE DID
INCREASE POPS INTO THE CATEGORICAL RANGE FOR THOSE LOCATIONS BASED
ON THE MULTI-MODEL CONSENSUS AND UPSTREAM TRENDS. MOISTURE CHANNEL
IMAGERY SHOWS SOME MODEST DRYING WITH THE SHORT WAVE...AND WE HAVE
EVEN NOTED SOME LIGHTNING WITH THE FEATURE ACROSS NORTHEAST NEVADA
THIS MORNING...SO IT/S DYNAMICALLY-ROBUST IN AN UNSTABLE AIR MASS.
WE ARE THUS CALLING FOR SEVERAL INCHES OF SNOW IN THE MOUNTAINS...
THOUGH WARM AIR ADVECTION COULD ACTUALLY CAUSE SNOW LEVELS TO RISE
TO 8500 FT MSL AROUND COOKE CITY IF THE 12 UTC NAM IS CORRECT.
WE RETAINED LIKELY POPS FOR BILLINGS AND CHANCE-STYLE POPS FOR THE
REMAINDER OF THE PLAINS THIS AFTERNOON AND EVENING AS 700-HPA WARM
AIR ADVECTION RAMPS UP. BILLINGS COULD BE ON THE EDGE OF THE BATCH
OF PRECIPITATION TO THE WEST OF THE CITY IF THE 12 UTC GUIDANCE IS
CORRECT...SO WE FELT COMFORTABLE KEEPING POPS THERE AT 60 PERCENT.
SCHULTZ
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MODELS IN GOOD AGREEMENT WEDNESDAY INTO EARLY NEXT WEEKEND BUT
DIVERGE QUITE A BIT BY NEXT SUNDAY. MUCH BELOW NORMAL TEMPERATURES
CAN BE EXPECTED ALONG WITH CHANCES FOR SNOW SHOWERS AT TIMES.
WEDNESDAY AND THURSDAY MODELS SHOW A LARGE TROUGH CARVED OUT
ACROSS THE CENTRAL AND NORTHERN ROCKIES. A LARGE UPPER LOW WILL BE
SITUATED OVER EAST CENTRAL CANADA WITH A STRONG JET WELL SOUTH OF
OUR AREA ACROSS THE FOUR CORNERS REGION INTO COLORADO. AS A
RESULT...BOTH THESE LOCATIONS WILL BE WHERE THE STRONGEST DYNAMICS
AND ENERGY WILL BE LOCATED. AT THIS TIME...JUST ISOLATED TO
SCATTERED SNOW SHOWERS ARE EXPECTED WEDNESDAY THROUGH FRIDAY.
BEST CHANCES WILL BE ALONG AND WEST OF A SHERIDAN TO BILLINGS TO
ROUNDUP LINE AS LOW LEVEL UPSLOPE FLOW WILL PREVAIL. EAST OF THIS
LINE A MORE NORTHERLY FLOW WILL EXIST AND...AS A RESULT...HAVE
LOWERED POPS QUITE A BIT FOR THESE LOCATIONS.
AS FOR NEXT WEEKEND...MAINLY A NORTHWEST FLOW ALOFT ALONG WITH
SOME STREAMLINE VORTICITY WILL MOVE ACROSS THE FORECAST AREA WITH
NO STRONG FORCING SHOWING UP AT THIS TIME. DYNAMICS WILL WARRANT A
SLIGHT CHANCE FOR SNOW SHOWERS. TEMPERATURES WEDNESDAY THROUGH
FRIDAY WILL REMAIN IN THE 30S FOR HIGHS WITH OVERNIGHT LOWS IN THE
TEENS AND 20S. MODELS ARE HINTING AT SOME MODERATION IN
TEMPERATURES NEXT WEEKEND. HOWEVER...MODELS HAVE NOT BEEN HANDLING
WEATHER SYSTEMS TOO WELL OUT PAST 2 OR 3 DAYS LATELY SO FORECASTER
CONFIDENCE IS LOW FOR NEXT WEEKEND. HOOLEY
&&
.AVIATION...
ISOLATED LOWER ELEVATION RAIN SHOWERS AND MOUNTAIN SNOW SHOWERS
WILL CONTINUE FOR THE NEXT FEW HOURS...RESULTING IN AREAS OF MVFR
CONDITIONS. SHOWER COVERAGE WILL INCREASE ACROSS THE REGION BY
EARLY THIS AFTERNOON...WITH PERIODS OF IFR/LIFR CONDITIONS
POSSIBLE AT ALL TERMINALS AND ACROSS ALL ROUTES INTO THE EVENING
HOURS. SHOWER CHANCES WILL DECREASE OVERNIGHT WITH VFR CONDITIONS
RETURNING TO MUCH OF THE EASTERN TWO THIRDS OF THE REGION.
MOUNTAINS WILL BE OBSCURED INTO THE OVERNIGHT HOURS. STC
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 049 037/052 029/038 023/031 019/032 020/038 025/046
6/W 42/W 44/O 32/J 22/J 22/J 22/W
LVM 044 031/048 024/036 017/032 011/031 014/039 026/046
8/R 43/W 44/S 43/J 33/J 32/J 22/W
HDN 052 037/057 030/041 025/033 018/035 019/041 018/045
4/W 42/W 34/R 32/J 22/J 22/J 22/W
MLS 053 036/055 029/040 023/034 019/034 017/036 016/040
4/W 52/W 34/O 21/B 22/J 22/J 22/W
4BQ 054 036/059 030/039 025/036 018/033 019/036 018/040
4/W 52/W 34/O 31/B 22/J 22/J 12/W
BHK 047 033/058 030/039 024/035 019/033 019/035 018/040
4/W 52/W 34/R 21/B 22/J 22/J 22/W
SHR 052 035/056 031/039 024/033 019/033 020/040 018/043
4/W 42/W 34/R 43/J 33/J 22/J 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
117 PM CDT MON OCT 22 2012
.UPDATE...UPDATED THE FORECAST TODAY TO LOWER MAXIMUM TEMPERATURES
INTO THE 50S FOR MOST OF THE CWA AS STRATUS SHOULD HOLD TOUGH FOR
THE REST OF THE DAY INTO TONIGHT LOOKING AT LATEST SATELLITE AND
MODEL TRENDS. ALSO BEEFED UP THE DRIZZLE WORDING TO WIDESPREAD ON
THE NEBRASKA SIDE OF THE CWA AND EVEN ADDED SOME SHOWERS WITH
CONVECTIVE TYPE CELLS DEVELOPING ON RADAR AND CAN BE IDENTIFIED ON
VISIBLE SATELLITE. THE HRRR INDICATES THAT THIS ACTIVITY MAY
DIMINISH FOR A FEW HOURS IN THE EARLY AFTERNOON...BUT WILL RETURN
FOR THE REST OF THE AFTERNOON...AND EVEN INTO THE EVENING FOR
AREAS NORTH OF INTERSTATE 80. THE LOWER SUN ANGLE DOES NOT LOOK
LIKE ITS HELPING ANYTHING TOWARD GETTING CLEARING INTO OUR CWA
THIS AFTERNOON AND TONIGHT. INCREASE SKY COVER AND CONTINUED THIS
INTO TUESDAY MORNING. FOG LOOKS LIKE A GOOD BET TONIGHT INTO
TUESDAY MORNING AS ENSEMBLES CONTINUE TO INDICATE
THIS...ESPECIALLY WEST.
&&
.AVIATION...18Z KGRI TAF. WE WILL BE SOCKED IN WITH STRATUS AND
CONTINUED GENERALLY POOR CONDITIONS FOR THIS FORECAST...AS THE
TERMINAL WILL BE NORTH OF A STALLED SURFACE BOUNDARY DOWN IN
KANSAS. DRIZZLE SHOULD DIMINISH BY THIS EVENING...BUT ENSEMBLES
INDICATE FOG SETTLING IN AND LOWERING STRATUS AFTER A TEMPORARILY
MODEST RAISING OF CEILINGS THIS AFTERNOON/EVENING. THE BOUNDARY
SHOULD SHIFT NORTH OF THE TERMINAL BY TUESDAY AFTERNOON...BUT THIS
WILL BE AFTER THE VALID TIME OF THIS FORECAST.
&&
PREV DISCUSSION... /ISSUED 513 AM CDT MON OCT 22 2012/
SHORT TERM...THROUGH WEDNESDAY NIGHT. DESPITE THE MAJORITY OF
THE NEXT 72 HOURS LIKELY REMAINING VOID OF MEASURABLE PRECIP
CHANCES...THERE ARE NONETHELESS A PLETHORA OF TRICKY
CHALLENGES...INCLUDING HIGH TEMPERATURES AND SKY COVER JUST TO
NAME A FEW. THE FINAL 24 HOURS OF THIS PERIOD WILL FEATURE THE
WELL-ADVERTISED COLD FRONT THAT WILL USHER IN THE SHARPLY COOLER
CHANGES FOR THE LATTER HALF OF THE WEEK.
09Z OBJECTIVE SURFACE ANALYSIS PLACES A 1003MB LOW OVER CENTRAL
KS...WITH A SOUTHWEST-NORTHEAST ORIENTED AND VERY SLOW MOVING/SOME
PLACES NEARLY STALLED COLD FRONT DRAPED BEHIND THIS LOW FROM
SOUTHWEST KS INTO WEST CENTRAL IA...AND BARELY CUTTING ACROSS THE
SOUTHEAST EDGE OF THE CWA MAINLY FROM HEBRON-BELOIT. TO THE NORTH
OF THIS BOUNDARY...FAIRLY STEADY NORTHERLY BREEZES OF 10-15 MPH
WITH SOME HIGHER GUSTS HAVE PREVAILED THROUGH THE NIGHT...WITH
DEWPOINTS PRIMARILY IN THE 40S. MEANWHILE...ALONG THE FRONT
ITSELF...LIGHT/VARIABLE BREEZES ARE THE NORM WITH QUITE A POOLING
OF DEWPOINTS IN THE UPPER 50S-MID 60S EVIDENT AT AUTOMATED
STATIONS SUCH AS HEBRON/BELOIT. NOT SURPRISINGLY...THE LATEST OBS
ARE HINTING AT A POSSIBLE EXPANSION OF DENSE FOG IN THESE EXTREME
SOUTHEAST PORTIONS OF THE CWA. OTHERWISE...11-3.9 MICRON SATELLITE
IMAGERY HAS INDICATED QUITE AN EXPLOSION OF LOW STRATUS GENERALLY
AROUND 1000 FT AGL THROUGH THE NIGHT...WITH THIS EXPANDING CLOUD
SHIELD NOW BLANKETING NEARLY THE ENTIRE CWA AND EXPANDING SOUTH-
SOUTHEAST WITH TIME. PRECIP-WISE...A FAIRLY ORGANIZED LINE/CLUSTER
OF ELEVATED THUNDERSTORMS GOT UNDERWAY IN SOUTHEAST NEBRASKA
EARLIER IN THE NIGHT AND IS NOW STREAMING NORTHEAST ACROSS
IA/NORTHERN MO...WITH NO HINT OF SHOWER/STORM DEVELOPMENT WITHIN
THE CWA THROUGH THE NIGHT. ALOFT...WATER VAPOR SATELLITE IMAGERY
AND SHORT TERM MODEL DATA REVEAL A FAIRLY BUSY SOUTHWEST FLOW
PATTERN OVER THE CENTRAL PLAINS...AS ONE LOW AMPLITUDE SHORTWAVE
IS CURRENTLY LIFTING ACROSS THE NORTHEAST KS/SOUTHEAST NEB AREA
AND HELPING SPARK THE ONGOING CONVECTION TO THE EAST...WHILE OFF
TO THE SOUTHWEST ANOTHER EMBEDDED SHORTWAVE IS CRUISING TOWARD THE
TX PANHANDLE OUT OF NM. IN THE BIGGER PICTURE...A MORE ORGANIZED
LARGE SCALE SHORTWAVE TROUGH IS PLANTED OVER THE NORTHWEST
CONUS...ANCHORED BY A CLOSED 500MB LOW OFF THE SOUTHERN BRITISH
COLUMBIA COAST.
FOR TODAY...THE MOST NOTICEABLE FORECAST CHANGES WERE TO SKY COVER
AND RESULTANT HIGH TEMPERATURES. IN SHORT...ANY SEMBLANCE OF A
PARTLY CLOUDY LET ALONE MOSTLY SUNNY PERIOD TODAY HAS BEEN
STRIPPED FROM THE PREVIOUS FORECAST IN MOST AREAS...AND REPLACED WITH
CLOUDY/MOSTLY CLOUDY. THIS PESSIMISTIC CHANGE IS WELL-SUPPORTED BY
THE 00Z/06Z NAM...WHICH DEPICTS THE LARGE AND EXPANDING AREA OF
STRATUS REMAINING FIRMLY PLANTED OVER THE HEART OF THE CWA
ESSENTIALLY ALL DAY LONG...WITH MAYBE SOME HOPE FOR SOME MID-LATE
AFTERNOON CLEARING PRIMARILY ONLY FOR A HANDFUL OF FAR
SOUTHWESTERN COUNTIES. AT THE SURFACE...THE AFOREMENTIONED CENTRAL
KS LOW IS PROGGED TO WASH OUT A BIT DURING THE DAY AS IT DRIFTS
TOWARD THE SOUTHEAST NEB/SOUTHWEST IA BORDER AREA...WITH THE
STRATUS TRAPPED WITHIN THE WEAKENING FLOW ALONG THE NORTHWEST
PERIPHERY OF THIS FEATURE. ALOFT...THE UPSTREAM SHORTWAVE WILL
GENERALLY REMAIN SOUTH OF THE CWA AND LIFT ALONG THE KS/OK BORDER
THIS AFTERNOON. STARTING WITH THE MOST IMMEDIATE ISSUES...HAVE
AREAS OF FOG WITH LESS THAN 1 MILE VSBY WORDING GOING ACROSS THE
FAR SOUTHEAST CWA THROUGH 15Z...ALTHOUGH AT THIS TIME A FORMAL
DENSE FOG ADVISORY IS NOT PLANNED GIVEN THAT THE WORST CONDITIONS
SEEM TO BE CONFINED TO JUST ONE COUNTY...MITCHELL KS. AS FOR
THUNDERSTORM POSSIBILITIES...AFTER SOME DEBATE DECIDED TO GO AHEAD
AND STRIP OUT STORM WORDING POST-12Z FROM PREVIOUS
FORECAST...DESPITE THAT THE 03Z SREF CONTINUES TO SUGGEST THAT A
MORNING FLARE-UP IS NOT OUT OF THE QUESTION MAINLY IN THE EASTERN
HALF OF THE CWA IN THE PRESENCE OF 1000+ J/KG MUCAPE IN THE
850-700MB LAYER. HOWEVER...SEVERAL SHORT TERM HIGH RES AND
DETERMINISTIC MODELS SUCH AS THE NAM/HRRR AND 4M WRF-NMM ARE
RATHER INSISTENT THAT LACK OF FORCING BEHIND THE DEPARTING LEAD
SHORTWAVE...PARTLY DUE TO THE FACT THAT THE LOW LEVEL JET IS ALREADY
AIMED WELL EAST-SOUTHEAST OF THE CWA...WILL KEEP ANY ACTUAL
CONVECTION AT BAY ALTHOUGH IT COULD BE A CLOSE CALL.
OTHERWISE...GIVEN THE WIDESPREAD STRATUS...HAVE OPTED TO CARRY A
TOKEN PATCHY DRIZZLE WORDING THROUGH THIS MORNING FOR ROUGHLY THE
EASTERN 2/3 OF THE CWA...JUST IN CASE A FEW POCKETS OF DRIZZLE CAN
BE SQUEEZED OUT...ALTHOUGH THE DEPTH OF THE SATURATED WOULD SEEM A
BIT MARGINAL FOR THIS TO HAPPEN. FOR THIS AFTERNOON...HAVE A
COMPLETELY DRY FORECAST BUT ITS NOT OUT OF THE QUESTION THAT A
PATCHY DRIZZLE MENTION MIGHT NEED EXTENDED DEPENDING ON HOW THE
MORNING PLAYS OUT. HIGH TEMP WISE...LOWERED 3-6 DEGREES FROM
PREVIOUS FCST IN MOST AREAS...BUT VERY POSSIBLY NOT ENOUGH. FOR
NOW WILL RUN WITH NEAR 60 NORTH TO UPPER 60S SOUTH...WHICH FOR
SOME AREAS IS NEARLY 10 DEGREES COOLER THAN THE FORECAST FROM 24
HOURS AGO. STILL...IF THIS STRATUS HOLDS FIRM DAY SHIFT MAY VERY
WELL HAVE TO MAKE AN EVEN MORE DRASTIC DOWNTURN AND KEEP MANY
AREAS STUCK IN THE 50S.
TONIGHT...THERE CONTINUES TO BE A FAIRLY CONSISTENT SIGNAL THAT
THE BLANKET OF LOW STRATUS WILL VACATE/ERODE FROM SOUTHWEST-
NORTHEAST AFTER SUNSET AS SOUTH-SOUTHWEST LOW LEVEL FLOW
INCREASES...ESPECIALLY EVIDENT AT 850MB. TIME WILL TELL WHETHER
THIS CLEARING IS AS RAPID AS ADVERTISED. ANOTHER CONSISTENT
MODEL/GUIDANCE SIGNAL AFTER MIDNIGHT TONIGHT HAS BEEN THE
DEVELOPMENT OF A FAIRLY EXPANSIVE AREA OF FOG WITH VISIBILITY
POTENTIAL TO AROUND 1 MILE OR LOWER. IN GENERAL...MODELS SUCH AS
THE SREF FAVOR THE WESTERN 1/2 OF THE CWA FOR THE GREATEST FOG
COVERAGE. PREVIOUS SHIFT INTRODUCED AREAS OF FOG THOUGH CWA-
WIDE...AND AM NOT ABOUT TO GET CUTE AND TAKE ANY AREAS OUT GIVEN
THE GENERALLY LIGHT/VARIABLE SURFACE FLOW EXPECTED. CAN/T SAY YET
WHETHER SOME AREAS MAY NEED A DENSE FOG HEADLINE...BUT WILL
CONTINUE TO CARRY VSBY RESTRICTIONS IN THE HWO. CHANGED LOW TEMPS
LITTLE PER MET/MAV GUIDANCE BLENDED WITH CONSALL...RESULTING IN
MID 40S WEST TO LOW 50S SOUTHEAST.
TUESDAY...THIS IS STILL LOOKING HANDS DOWN LIKE THE WARMEST DAY OF
THE WEEK...ASSUMING THAT SKIES CLEAR EFFICIENTLY IN THE WAKE OF
ANY POTENTIAL MORNING STRATUS/FOG. ALOFT...BROAD WEST-SOUTHWEST
FLOW WILL PERSIST...AS THE MAIN FORCING FOR PRECIPITATION REMAINS
WELL NORTHWEST IN ASSOCIATION WITH A SHORTWAVE TROUGH EJECTING
NORTHEAST ACROSS THE NORTHERN ROCKIES. KEPT HIGHS SIMILAR TO
PREVIOUS FORECAST PER A BLEND OF VARIOUS GUIDANCE/MODELS...WITH
MOST OF THE CWA AIMED INTO THE UPPER 70S AND LOW 80S MOST FAVORED
IN SOME OF THE SOUTHERN-MOST COUNTIES.
TUESDAY NIGHT...KEPT ANY FOG MENTION OUT OF THE FORECAST FOR
NOW...ALTHOUGH THE NAM AND SREF AGAIN EARMARK THE
EASTERN/NORTHEAST CWA FOR POSSIBLE VISIBILITY RESTRICTIONS...AND
THERE COULD ALSO BE A NORTHWARD SURGE OF LOW STRATUS INTO MUCH OF
THE CWA THROUGH THE NIGHT AS WELL AS SOUTHERLY LOW LEVEL FLOW
RAMPS UP AHEAD OF APPROACHING CENTRAL ROCKIES SHORTWAVE ENERGY.
KEPT LOW TEMPS SIMILAR TO PREVIOUS AND GENERALLY 2-3 ABOVE
GUIDANCE BLEND...RANGING MID 40S NORTHWEST TO UPPER 50S SOUTHEAST
WHERE DEWPOINTS WILL BE ON THE RISE.
WEDNESDAY...KEPT IT DRY FOR NOW WITH THE ASSUMPTION THAT THE CWA
WILL REMAIN CAPPED IN THE VICINITY OF A RATHER SHARP INVADING COLD
FRONT...ALTHOUGH THE GFS IS HINTING THAT SOME STORMS MIGHT ATTEMPT
FORMING NEAR THE FAR SOUTHEAST CWA IN THE AFTERNOON BUT WILL
DISCOUNT FOR NOW. THE BIG STORY WILL CERTAINLY BE THE INVADING
FRONT...AS NORTHERLY WINDS KICK INTO ALL BUT PARTS OF THE
SOUTHEAST...AND SPEEDS WERE RAISED 5-10 MPH FROM PREVIOUS GRIDS.
THE TIMING OF THIS FRONT AND RESULTANT HIGH TEMPS CONTINUES TO BE
A NIGHTMARE...AS THERE COULD EASILY BE A 25+ DEGREE HIGH TEMP
GRADIENT ACROSS THE CWA BASED ON THE CURRENT GENERAL EXPECTATION.
HOWEVER...MODELS HAVE NOT LOCKED INTO STEP COMPLETELY YET...AND
ADJUSTMENTS OF 10+ DEGREES FROM THE CURRENT FORECAST ARE STILL NOT
OUT OF THE QUESTION. AT LEAST FOR NOW THOUGH...LOWERED MOST OF THE
CWA A FEW DEGREES FROM PREVIOUS FORECAST...BUT SLIGHTLY RAISED THE
SOUTHEAST. AGAIN...DO NOT TAKE TOO LITERALLY...BUT AM AIMING FOR A
RANGE FROM LOW 60S NORTHWEST...MID 60S TO LOW 70S TRI-CITIES AREA
AND LOW-MID 80S FAR SOUTHEAST.
WEDNESDAY NIGHT...CLEARLY THIS IS THE NEXT BEST CHANCE OF AT LEAST
LIGHT MEASURABLE PRECIP...AS THE CWA COMES UNDER INCREASING
FORCING/JET DYNAMICS AND RESULTANT MID LEVEL SATURATION AS THE
LEADING EDGES OF A FAIRLY POTENT OPEN SHORTWAVE TROUGH ARRIVES IN
THE CENTRAL PLAINS. KEPT AT LEAST 20 POPS NEARLY ALL AREAS...BUT
NUDGED SOME AREAS NORTH OF I-80 INTO 40 PERCENT RANGE. MAIN CHANGE
WAS TO INTRODUCE THUNDER MENTION FOR ROUGHLY THE SOUTHEAST 1/2 OF
THE CWA. THIS THUNDER MENTION MAY EVENTUALLY NEED PUT ALL
AREAS...BUT WITH THE NAM DEPICTING AT LEAST 500-1000 J/KG MUCAPE
PRIMARILY IN SOUTHEAST ZONES FIGURED THIS WAS A START FROM THE
PRIOR NON-THUNDER FORECAST. SUPPOSE SOME SMALL HAIL IS NOT OUT OF
THE QUESTION AS DEEP LAYER SHEAR INCREASES CONSIDERABLY. DESPITE
SOME COLD AIR ALOFT EDGING INTO NORTHWEST ZONES BY LATE IN THE
NIGHT...AM EXPECTING ALL PRECIP TO REMAIN LIQUID WITH ANY POSSIBLE
NOW WELL OFF INTO WESTERN NEB.
LONG TERM...STARTING 12Z THURSDAY...UNSEASONABLY COOL TEMPERATURES
AND A COUPLE SMALL CHANCES FOR PRECIP WILL BE THE FOCUS THROUGH THE
EXTENDED PERIODS AS A COOL AIRMASS SETTLES IN ACROSS THE PLAINS
BEHIND WEDNESDAYS COLD FRONT. THE ASSOCIATED SURFACE HIGH BEHIND
THIS FRONT WILL EVENTUALLY SHIFT EAST LATE IN THE UPCOMING
WEEKEND...ALLOWING THE LOW LEVEL FLOW TO BECOME MORE SOUTHERLY AND
FOR POTENTIALLY A RETURN TO MORE SEASONAL TEMPERATURES JUST BEYOND
THE CURRENT SCOPE OF THE FORECAST.
IN THE MEANTIME...MODELS IN FAIR AGREEMENT KEEPING A BROAD UPPER
LEVEL TROUGH OF LOW PRESSURE CENTERED ACROSS THE CENTRAL AND
NORTHERN PLAINS THROUGH THE EXTENDED PERIODS...WITH MULTIPLE UPPER
LEVEL SHORTWAVES ROUNDING THE BASE OF THIS TROUGH...WHICH ARE
EXPECTED TO BRING SMALL CHANCES FOR PRECIP ON THURSDAY AND AGAIN
FRIDAY. WHILE OVERALL CHANCES FOR MEASURABLE PRECIP DO NOT APPEAR
GREAT AT THIS TIME...EXPECT THERE TO BE ENOUGH LOW LEVEL MOISTURE IN
PLACE ALONG WITH BROAD SCALE LIFT TO GENERATE SOME LIGHT RAIN ACROSS
THE AREA ON THURSDAY. THEREAFTER...PRECIP CHANCES BECOME A BIT MORE
DICEY...AS THERE APPEARS TO BE LESS LOW LEVEL MOISTURE TO WORK WITH
ON FRIDAY AND TIMING OF PRECIP APPEARS EARLIER IN THE DAY...SO COULD
ACTUALLY SEE A MIX OF SOME LIGHT RAIN OR SNOW DURING THE MORNING
HOURS FRIDAY IF PRECIP DOES DEVELOP. WITH LATEST EC BACKING OFF ON
POPS COMPLETELY FOR FRIDAY...DECIDED TO REDUCE ALLBLEND POPS DOWN A
BIT...WITHOUT REMOVING...AS BOTH EC AND GFS SHOW AN UPPER LEVEL WAVE
TRACKING ACROSS THE REGION DURING THE MORNING HOURS.
OTHERWISE...TEMPERATURES WILL REMAIN SEASONABLY COLD THROUGH THE
PERIOD...WITH GENERALLY HIGH TEMPERATURES IN THE 40S AND LOWER 50S
POSSIBLE THROUGHOUT...AND LOW TEMPERATURES BOTTOMING OUT IN THE 20S
AND LOWER 30S EACH MORNING. AT THIS TIME...FRIDAY AND SATURDAY
APPEAR TO BE THE COLDEST DAYS OF THE EXTENDED AS THE SURFACE HIGH
WILL EXTEND ACROSS THE LOCAL AREA THOSE DAYS...WITH TEMPERATURES NOT
EXPECTED TO CLIMB OUT OF THE 40S EITHER DAY...WITH POSSIBLY EVEN
SOME HIGH TEMPERATURES IN THE 30S MIXED IN FRIDAY AFTERNOON IF
PRECIPITATION AND CLOUD COVER ARE EVENTUALLY REALIZED WITH PASSING
SHORTWAVE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION/UPDATE...HEINLEIN
SHORT TERM...PFANNKUCH
LONG TERM...ROSSI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1222 PM CDT MON OCT 22 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
351 AM CDT MON OCT 22 2012
AT 3 AM...A BAND OF SHOWERS AND THUNDERSTORMS WERE DEVELOPING
ALONG A WARM FRONT ACROSS SOUTHWEST IOWA AND NORTHERN MISSOURI.
THE LATEST RAP SHOWS THAT THERE IS STRONG 900 TO 800 MB
FRONTOGENESIS. IT SHOWS THAT AS THIS BAND MOVES NORTHEAST TOWARD
THE AREA THAT THIS FRONTOGENESIS GRADUALLY WEAKENS. IN
ADDITION...THESE STORMS WILL BE MOVING INTO AN AREA OF LESS
INSTABILITY. THEREFORE THINKING THAT THE THUNDERSTORMS WILL BECOME
MORE ISOLATED AS THEY MOVE THROUGH OUR AREA THIS MORNING AND EARLY
THIS AFTERNOON. WITH THE BEST MOISTURE TRANSPORT MAINLY OVER
NORTHERN ILLINOIS...THE HIGHEST PRECIPITATION PROBABILITIES SHOULD
BE LOCATED ACROSS NORTHEAST IOWA...AND SOUTHWEST AND CENTRAL
WISCONSIN. MANY OF THE MESO MODELS SUGGEST THAT THE CONVECTION
WILL EVOLVE INTO A LINE AS IT MOVES NORTHEAST THROUGH THE AREA. AS
A RESULT...TRIED TO TIME THE HIGHEST PRECIPITATION PROBABILITIES
TO ITS PARENT SHORT WAVE TROUGH. BUFKIT SOUNDINGS SHOW VERY SKINNY
CAPE ACROSS THE AREA...SO THE CHANCES OF ANY HAIL WITH ANY OF
THESE STORMS LOOKS RATHER MINUTE.
FOR TONIGHT...THE 22.00Z MODELS ARE IN FAIRLY GOOD AGREEMENT THAT
A WEAK LOW PRESSURE SYSTEM AND ITS WARM FRONT WILL APPROACH THE
AREA. THERE IS SOME WEAK TO MODERATE OMEGA AND ISENTROPIC LIFT
ASSOCIATED WITH THIS SYSTEM...SO EXPECT SOME LIGHT RAIN OR DRIZZLE
ACROSS THE AREA. THE SOUNDINGS SHOW THAT THERE WILL BE SOME
INSTABILITY ALOFT...BUT THERE IS SOME QUESTION WHETHER IT CAN BE
TAPPED. AS A RESULT...JUST LEFT ISOLATED THUNDERSTORMS IN THE FORECAST.
ON TUESDAY...THE MODELS SHOW THAT THE WARM FRONT WILL MOVE SLOWLY
NORTHEAST THROUGH THE AREA. THIS FRONT WILL USHER IN LOWER 60 DEW
POINTS AND TEMPERATURES IN THE 70S. IT WILL ALSO BE THE FOCUS FOR
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
ON TUESDAY NIGHT...BOTH THE NAM/WRF AND ECMWF SUGGEST THAT ANOTHER
SHORT WAVE TROUGH WILL MOVE NORTHEAST THROUGH THE AREA. DUE TO
THIS...KEPT A SLIGHT CHANCE OF PRECIPITATION IN THE FORECAST.
ON WEDNESDAY AFTERNOON AND EVENING...THE MODELS SHOW THAT A STRONG
COLD FRONT WILL MOVE EAST INTO THE FORECAST AREA. THE GEM AND
NAM/WRF ARE THE FASTEST AT MOVING THE COLD FRONT THROUGH THE AREA.
MEANWHILE THE ECMWF IS THE SLOWEST. THIS WILL GREATLY AFFECT THE
LOW TEMPERATURES ON WEDNESDAY NIGHT. IN ADDITION...WILL HAVE TO WATCH THIS
COLD FRONT FOR THE POSSIBILITY OF SEVERE WEATHER. THE NAM/WRF
SHOWS A LOW PRESSURE SYSTEM MOVING ALONG THIS FRONT WHICH HELPS
INCREASE THE LOW LEVEL SHEAR ACROSS THE AREA. THE 0-1 KM BULK SHEAR
EXCEEDS 25 KNOTS AND THE 0-1 KM HELICITY EXCEEDS 300 M2/S2 FROM
NORTH CENTRAL IOWA NORTHEAST INTO NORTHWEST WISCONSIN. THE ML
CAPES CLIMBS APPROACHES 2K. THIS HELPS THE SIGNIFICANT TORNADO
PARAMETER CLIMB TO 5. THE GFS ALSO SHOWS A POSSIBILITY OF
TORNADOES...BUT ITS VALUES ARE MUCH WEAKER. THE TORNADO
POSSIBILITIES WILL DEPEND A LOT ON WHETHER THE STORMS ARE ABLE TO
BECOME SURFACE BASED OR NOT. THE NAM/WRF WOULD SUGGEST THAT THEY
WILL BECOME SURFACE BASED DURING THE AFTERNOON. MEANWHILE THE GFS
WOULD SAY THAT THEY WILL REMAIN ELEVATED. FOR THE TIME
BEING...WILL JUST MENTION THE POSSIBILITY OF SEVERE WEATHER IN THE
HAZARDOUS WEATHER OUTLOOK.
.LONG TERM...THURSDAY THROUGH SUNDAY
351 AM CDT MON OCT 22 2012
ON THURSDAY...STRONG COLD AIR ADVECTION WILL MOVE INTO THE AREA.
AS THIS OCCURS...EXPECT THE TEMPERATURES TO FALL RAPIDLY INTO THE
40S BY THE AFTERNOON.
ON FRIDAY NIGHT...BOTH THE GFS AND ECMWF HAVE SHIFTED A LOW
PRESSURE SYSTEM FURTHER SOUTHEAST AWAY FROM THE AREA. MEANWHILE
THE GEM DEVELOPS A WAVE ALONG THE FRONT TO OUR SOUTHEAST AND THIS
BRINGS THE PRECIPITATION NORTHWEST INTO NORTHEAST IOWA AND
SOUTHWEST AND CENTRAL WISCONSIN. THIS IS IMPORTANT BECAUSE THE
TEMPERATURES ALOFT WILL BE COLD ENOUGH FOR SOME SNOW. FOR THE TIME
BEING...JUST WENT WITH THE SLIGHT CHANCES THAT WERE IN THE ALL BLEND.
&&
.AVIATION...THIS AFTERNOON THROUGH TUESDAY
1222 PM CDT MON OCT 22 2012
CIGS/VSBYS PROBLEMATIC THROUGH THE PERIOD AS ONE WEAK SHORTWAVE
LIFTS BY THE AREA THIS AFTERNOON...THEN A WARM FRONT AND A VERY
MOIST SFC-850MB AIRMASS LIFT NORTH ACROSS THE AREA TONIGHT INTO TUE.
SHORTWAVE THIS AFTERNOON WILL BE RESPONSIBLE FOR SCT -SHRA/ISOLATED
TSRA ACROSS THE AREA. A MOIST LOW LEVEL AIRMASS WILL CONTINUE TO BE
PULLED NORTH INTO THE AREA THIS AFTERNOON/TONIGHT...AHEAD OF BROADER
LOW PRESSURE MOVING INTO THE CENTRAL/NORTHERN PLAINS. THE PLAINS LOW
WILL PUSH A WARM FRONT NORTH INTO THE AREA TONIGHT...PROVIDING THE
FOCUS FOR CONVERGENCE AND LIFT OF THE MOIST LOW LEVEL AIRMASS. ALONG
WITH DIURNAL COOLING...CIGS EXPECTED TO LOWER TO IFR TONIGHT INTO
TUE...ALONG WITH MVFR/IFR VSBYS IN BR. MAY BE SOME LIFR IN FG OVER
THE HIGHER TERRAIN AREAS LATE TONIGHT/EARLY TUE UNTIL THE FRONT
LIFTS NORTH OF THE AREA. ENOUGH DEPTH OF MOISTURE AND THE
LIFT...APPEARS -DZ PERHAPS -RA TO BE RATHER WIDESPREAD TONIGHT INTO
TUE MORNING. CONTINUED -DZ IN BOTH KRST/KLSE TAFS FROM 05-15Z. ONCE
THE FRONT LIFTS NORTH OF THE TAF SITES TUE MORNING AND WINDS
INCREASE FROM THE SOUTH...CIGS/VSBYS SHOULD GRADUALLY IMPROVE WITH
THE INCREASED MIXING AND THE LIFT MOVING NORTH OF THE AREA.
CIGS/VSBYS EXPECTED TO REMAIN MVFR THRU THE MORNING...TRENDING
TOWARD VFR TUE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
313 AM CDT MON OCT 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
110 PM MDT MON OCT 22 2012
.AVIATION...18Z TAFS. VFR. PERIODS OF MIDDLE AND HIGH CLOUDS WITH
CEILINGS ABOVE 12000 FEET AGL...EXCEPT FOR AREAS OF MVFR AND IFR
CEILINGS IN SHOWERS AFTER 12Z/TUESDAY ACROSS CARBON COUNTY AND
OVER THE SNOWY AND SIERRA MADRE RANGES AND NORTHERN LARAMIE RANGE
...WITH HIGHER PEAKS OVER THE SNOWY AND SIERRA MADRE PEAKS
OBSCURED AFTER 12Z/TUESDAY IN SHOWERS...CLOUDS AND FOG.
SOUTHWEST WINDS INCREASING SIGNIFICANTLY AFTER
12Z/TUESDAY...ESPECIALLY ACROSS CARBON AND ALBANY COUNTIES. AFTER
12Z/TUESDAY...EXPECT AN INCREASE IN MOUNTAIN WAVE CLOUDINESS...LEE
EDDY EFFECTS AND A DEVELOPING MOUNTAIN WAVE AND INCREASING
TURBULENCE...ESPECIALLY WEST OF INTERSTATE 25. RUBIN
&&
.PREV DISCUSSION... /ISSUED 1049 AM MDT MON OCT 22 2012/
UPDATE...
WENT AHEAD AND UPGRADED HIGH WIND WATCHES FOR THE BORDEAUX AND
ARLINGTON AREAS TO WARNINGS WITH THE MORNING UPDATE. STILL NOT
CONVINCED THAT OTHER ZONES...NAMELY THE SOUTHERN LARAMIE
RANGE...MAY NEED TO BE ADDED. WILL TAKE ANOTHER LOOK FOR THE
AFTERNOON PACKAGE. ALSO LOWERED MAX TEMPERATURES TODAY OUT IN THE
PANHANDLE BY SEVERAL DEGREES AS THE STRATUS IS HANGING TOUGH OUT
THAT WAY. UPDATES HAVE BEEN SENT.
CLAYCOMB
PREV DISCUSSION... /ISSUED 601 AM MDT MON OCT 22 2012/
AVIATION...12Z TAF ISSUANCE...
OBS AND SATELLITE IMAGERY GENERALLY SHOW IFR CIGS ACROSS THE
NEBRASKA PANHANDLE. LOW CLOUDS HAVE BEEN TRYING TO PUSH INTO
SOUTHEAST WYOMING BUT ARE NOT MAKING MUCH HEADWAY OVER THE PAST
FEW HOURS. KSNY IS SEEING THE LOWEST VIS/CIGS AND WILL CONTINUE
THIS THROUGH THE LATE MORNING. LOW CLOUDS WILL PERSIST THROUGH
AROUND 18Z BEFORE DISSIPATING. VFR CONDITIONS WILL OCCUR AT THE WY
SITES THROUGH THE ENTIRE TAF PERIOD. SOUTHWEST WINDS WILL BECOME
WINDY THIS AFTERNOON TO THE WEST OF THE LARAMIE RANGE...WITH GUSTS
OCCASIONALLY REACHING 30-35 KTS.
PREV DISCUSSION... /ISSUED 427 AM MDT MON OCT 22 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY...
BUILDING DOWN STRATUS HAS LED TO A FOGGY START TO THE DAY FOR
PORTIONS OF THE EASTERN PLAINS GENERALLY BELOW 5 KFT. THE FOG
PRODUCT CONTINUES TO SHOW BANK OF STRATUS/FOG BACKING
WEST/SOUTHWEST. LATEST HRRR OUTPUT SUGGEST THE WESTWARD PROGRESS
OF THE FOG SHOULD SLOW TOWARDS DAYBREAK. FOG WILL BEGIN TO LIFT BY
LATE MORNING AS THE LLVLS BEGINS TO MIX AND BECOME COUPLED.
OTHERWISE AN AREA OF LIGHT SHOWERS WILL CONTINUE ACROSS CARBON AND
CONVERSE COUNTIES THIS MORNING AS AN EMBEDDED SHORTWAVE LIFTS
NORTHEAST. BEST MOISTURE WILL BE HELD BACK ACROSS WESTERN
WYOMING...SO THESE SHOWERS WILL REMAIN LIGHT PRODUCING LITTLE TO
NO PRECIPITATION. TEMPERATURES WILL BE SLIGHTLY WARMER TODAY AS
H7 TEMPERATURES CLIMB NEAR 6-7C.
ATTENTION THEN TURNS TO A POSSIBLE HIGH WIND EVENT FOR WIND PRONE
AREAS LATER LATE THIS EVENING THROUGH MID-MORNING ON TUESDAY.
LATEST MODEL GUIDANCE IS CONSISTENT IN PAINTING A POCKET OF 50-60
KNOT H7 WINDS DEVELOPING ACROSS CARBON COUNTY AND THE NRN LARAMIE
RANGE AFTER 03Z. THE PROGD KCAG-KCPR GRADIENTS REMAIN ON THE LOW-
SIDE OF TYPICAL WARNING CRITERIA...HOVERING BETWEEN 47 AND 53
METERS AT H85 AND H7 BY MIDNIGHT. HOWEVER...THESE MAY BE OVERCOME
AS THE SUBSIDING RFQ OF A 110 KNOT JET STREAK WORKS INTO THE AREA
TONIGHT. IN ADDITION...THE DEVELOPMENT OF A STABLE LAYER DOWN TO
AROUND H7 WILL AID IN THE POTENTIAL FOR STRONG WINDS AT THE
TYPICAL WIND PRONE AREAS OF ARLINGTON AND BORDEAUX. SO...HAVE
ISSUED A HIGH WIND WATCH FOR THESE AREAS FROM 9P TONIGHT THROUGH
9A TUESDAY. ALTHOUGH WINDS WILL REMAIN BREEZY ACROSS OTHER LOWER
ELEVATIONS OF CARBON/ALBANY COUNTIES TONIGHT...DO NOT ANTICIPATE
THAT THESE AREAS WILL REMAIN COUPLED THRU THE OVERNIGHT HOURS AND
THUS SHOULD NOT SEE THESE STRONG WINDS. STRONGEST WINDS WILL
DEPART ON TUESDAY SO ALTHOUGH WINDS WILL REMAIN BREEZY...EXPECT
THEM TO LESSEN THROUGH THE DAY. PRECIPITATION CHANCES WILL
INCREASE ACROSS CARBON...CONVERSE AND NIOBRARA COUNTIES ON TUESDAY
AFTERNOON AS THIS AREA REMAINS ON THE WARM SIDE OF THE STRONG SW/NE
ORIENTED JET STREAK. TEMPERATURES WILL BE COOLER WEST OF THE
LARAMIE RANGE FOR TUESDAY WHILE EASTERN PLAINS WILL REMAIN WARM.
BY WEDNESDAY...THE NEXT CYCLONICALLY CURVED JET STREAK WILL NOSE
INTO COLORADO PLACING THE FAVORABLE LFQ OVER THE CWA. THIS WILL
COMBINE WITH A SURFACE COLD FRONT THAT WILL DROP SOUTH THROUGH THE
AREA DURING THE DAY. BEHIND THE FRONT...UPSLOPE FLOW ALONG WITH
THE LAGGING MID-LEVEL FRONTOGENESIS WILL COMBINE WITH OVERRUNNING
MOISTURE AND THE AFOREMENTIONED LFQ TO BEGIN TO PRODUCE MORE
WIDESPREAD PRECIPITATION ESPECIALLY DURING THE AFTERNOON HOURS.
FORTUNATELY...TEMPERATURES WILL BE WARM ENOUGH FOR PRECIPITATION
TO REMAIN ALL RAIN AT THIS POINT. THIS CHANGES IN SUBSEQUENT
PERIODS IN THE LONG TERM HOWEVER. UNSETTLED WEATHER ALONG WITH
COOLER AIR...WILL HOLD TEMPERATURES DOWN ON WEDNESDAY...WITH 40S
FOR NORTHERN AND WESTERN ZONES...AND 50S ELSEWHERE.
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...
MODELS CONTINUE TO HONE IN ON THE WED NIGHT PERIOD AS A
FAVORABLE TIME FOR WIDESPREAD PRECIP OVER THE CWA. THE GFS AND
ECMWF BOTH SHOW A STRONG SHORTWAVE MOVING OVER NORTHERN COLORADO ON
WED NIGHT WITH MOST OF THE CWA IN THE LEFT EXIT REGION OF THE 250MB
JET BETWEEN 00-12Z THURS. THICKNESSES AND SOUNDINGS SUGGEST THAT
SNOW WILL BE THE PRECIP TYPE ON WED NIGHT. PRECIP COULD START OUT
INITIALLY AS A MIX OF RAIN AND SNOW IN THE NEBRASKA PANHANDLE ON WED
EVENING...THEN TRANSITION QUICKLY TO SNOW AS COLD AIR ADVECTION
CONTINUES THROUGH THE EARLY NIGHT HOURS. MODEL QPF CONSENSUS IS IN
THE 0.25-0.50 INCH RANGE FOR THIS FIRST WAVE. SHORTWAVE AND ITS
ASSOCIATED DEEP LAYER LIFT MOVES EAST OF THE REGION ON THURS MORNING
WITH SNOW RATES DROPPING OFF. THE MODELS SHOW BROAD CYCLONIC FLOW
ON THURS WITH LLVL UPSLOPE ALONG AND EAST OF THE LARAMIE RANGE.
DROPPED HIGH TEMPERATURES ON THURS INTO THE LOW-TO-MID 30S OVER THE
PLAINS WITH CLOUD COVER...UPSLOPE...AND SNOW COVER MAKING IT
DIFFICULT TO GET MUCH WARMING. ALTHOUGH UPPER LEVEL FORCING IS WEAK
ON THURS...LLVL UPSLOPE COULD BE SUFFICIENT TO GENERATE SOME WEAK
SNOW SHOWERS/FLURRIES MAINLY ALONG THE LARAMIE RANGE.
THE NEXT STRONG SHORTWAVE IN THE CYCLONIC MIDLEVEL FLOW IS PROGGED
TO TREK FROM UTAH INTO COLORADO ON THURS NIGHT. WITH DEEP LAYER
UPWARD MOTION INCREASING ON THURS NIGHT...AND LLVL UPSLOPE ALREADY
IN PLACE...WOULD EXPECT ANOTHER ROUND OF SNOW ESPECIALLY OVER THE
SOUTHERN ZONES. NEED TO CONTINUE TO MONITOR THE TRACK OF THIS
SHORTWAVE AS A SHIFT TO THE NORTH OR SOUTH WOULD OBVIOUSLY HAVE
IMPLICATIONS ON QPF AMOUNTS. SNOW COMES TO AN END BY MIDDAY FRI
AS THE FORCING EXITS THE AREA. ANOTHER COLD DAY ON FRI WITH
TEMPERATURES AROUND 25-30 DEGREES BELOW NORMAL FOR LATE OCTOBER.
NORTHWESTERLY MIDLEVEL FLOW BECOMES ESTABLISHED OVER SOUTHEAST
WYOMING ON SAT WITH DRYING IN LOW AND MIDLEVELS. NOT GOING TO SEE
ANY BIG WARMUP UNTIL SUN...WHEN THE SFC HIGH PRESSURE OVER THE
PLAINS IS REPLACED BY A DEVELOPING SFC TROUGH AND INCREASINGLY ZONAL
FLOW ALOFT.
FIRE WEATHER...
A FAIRLY ACTIVE WEEK TAKING SHAPE ACROSS THE DISTRICT WITH BREEZY
TO LOCALLY WINDY CONDITIONS FOR AREAS ALONG AND WEST OF THE
LARAMIE RANGE FOR MONDAY AND TUESDAY FOLLOWED BY A PROLONGED
PRECIPITATION EVENT THAT WILL BEGIN AS EARLY AS WEDNESDAY
AFTERNOON AND CONTINUE INTO FRIDAY. IF CURRENT FORECASTS HOLD THIS
WILL BRING IN MUCH COLDER AIR ALONG WITH LIGHT TO MODERATE SNOW
ACCUMULATIONS. BEFORE THEN...TEMPERATURES WILL CONTINUE TO BE
UNSEASONABLY WARM TODAY AND TUESDAY WITH HIGHS THAT WILL CLIMB
INTO THE 60S AND 70S. WINDS MAY BECOME VERY STRONG ACROSS WIND
PRONE AREAS NEAR ARLINGTON AND BORDEAUX TONIGHT WITH WIND GUSTS TO
60 MPH POSSIBLE. MINIMUM RELATIVE HUMIDITIES SHOULD HOLD IN THE
20S AND 30S FOR BOTH TODAY AND TUESDAY. HOWEVER...THESE WILL
INCREASE AS COLDER UNSETTLED CONDITIONS WORK IN FOR THE LATTER
HALF OF THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM 9 PM MONDAY TO 9 AM TUESDAY FOR WYZ106-
WYZ110.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...HAHN
LONG TERM/AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1049 AM MDT MON OCT 22 2012
.UPDATE...
WENT AHEAD AND UPGRADED HIGH WIND WATCHES FOR THE BORDEAUX AND
ARLINGTON AREAS TO WARNINGS WITH THE MORNING UPDATE. STILL NOT
CONVINCED THAT OTHER ZONES...NAMELY THE SOUTHERN LARAMIE
RANGE...MAY NEED TO BE ADDED. WILL TAKE ANOTHER LOOK FOR THE
AFTERNOON PACKAGE. ALSO LOWERED MAX TEMPERATURES TODAY OUT IN THE
PANHANDLE BY SEVERAL DEGREES AS THE STRATUS IS HANGING TOUGH OUT
THAT WAY. UPDATES HAVE BEEN SENT.
CLAYCOMB
&&
.PREV DISCUSSION... /ISSUED 601 AM MDT MON OCT 22 2012/
AVIATION...12Z TAF ISSUANCE...
OBS AND SATELLITE IMAGERY GENERALLY SHOW IFR CIGS ACROSS THE
NEBRASKA PANHANDLE. LOW CLOUDS HAVE BEEN TRYING TO PUSH INTO
SOUTHEAST WYOMING BUT ARE NOT MAKING MUCH HEADWAY OVER THE PAST
FEW HOURS. KSNY IS SEEING THE LOWEST VIS/CIGS AND WILL CONTINUE
THIS THROUGH THE LATE MORNING. LOW CLOUDS WILL PERSIST THROUGH
AROUND 18Z BEFORE DISSIPATING. VFR CONDITIONS WILL OCCUR AT THE WY
SITES THROUGH THE ENTIRE TAF PERIOD. SOUTHWEST WINDS WILL BECOME
WINDY THIS AFTERNOON TO THE WEST OF THE LARAMIE RANGE...WITH GUSTS
OCCASIONALLY REACHING 30-35 KTS.
PREV DISCUSSION... /ISSUED 427 AM MDT MON OCT 22 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY...
BUILDING DOWN STRATUS HAS LED TO A FOGGY START TO THE DAY FOR
PORTIONS OF THE EASTERN PLAINS GENERALLY BELOW 5 KFT. THE FOG
PRODUCT CONTINUES TO SHOW BANK OF STRATUS/FOG BACKING
WEST/SOUTHWEST. LATEST HRRR OUTPUT SUGGEST THE WESTWARD PROGRESS
OF THE FOG SHOULD SLOW TOWARDS DAYBREAK. FOG WILL BEGIN TO LIFT BY
LATE MORNING AS THE LLVLS BEGINS TO MIX AND BECOME COUPLED.
OTHERWISE AN AREA OF LIGHT SHOWERS WILL CONTINUE ACROSS CARBON AND
CONVERSE COUNTIES THIS MORNING AS AN EMBEDDED SHORTWAVE LIFTS
NORTHEAST. BEST MOISTURE WILL BE HELD BACK ACROSS WESTERN
WYOMING...SO THESE SHOWERS WILL REMAIN LIGHT PRODUCING LITTLE TO
NO PRECIPITATION. TEMPERATURES WILL BE SLIGHTLY WARMER TODAY AS
H7 TEMPERATURES CLIMB NEAR 6-7C.
ATTENTION THEN TURNS TO A POSSIBLE HIGH WIND EVENT FOR WIND PRONE
AREAS LATER LATE THIS EVENING THROUGH MID-MORNING ON TUESDAY.
LATEST MODEL GUIDANCE IS CONSISTENT IN PAINTING A POCKET OF 50-60
KNOT H7 WINDS DEVELOPING ACROSS CARBON COUNTY AND THE NRN LARAMIE
RANGE AFTER 03Z. THE PROGD KCAG-KCPR GRADIENTS REMAIN ON THE LOW-
SIDE OF TYPICAL WARNING CRITERIA...HOVERING BETWEEN 47 AND 53
METERS AT H85 AND H7 BY MIDNIGHT. HOWEVER...THESE MAY BE OVERCOME
AS THE SUBSIDING RFQ OF A 110 KNOT JET STREAK WORKS INTO THE AREA
TONIGHT. IN ADDITION...THE DEVELOPMENT OF A STABLE LAYER DOWN TO
AROUND H7 WILL AID IN THE POTENTIAL FOR STRONG WINDS AT THE
TYPICAL WIND PRONE AREAS OF ARLINGTON AND BORDEAUX. SO...HAVE
ISSUED A HIGH WIND WATCH FOR THESE AREAS FROM 9P TONIGHT THROUGH
9A TUESDAY. ALTHOUGH WINDS WILL REMAIN BREEZY ACROSS OTHER LOWER
ELEVATIONS OF CARBON/ALBANY COUNTIES TONIGHT...DO NOT ANTICIPATE
THAT THESE AREAS WILL REMAIN COUPLED THRU THE OVERNIGHT HOURS AND
THUS SHOULD NOT SEE THESE STRONG WINDS. STRONGEST WINDS WILL
DEPART ON TUESDAY SO ALTHOUGH WINDS WILL REMAIN BREEZY...EXPECT
THEM TO LESSEN THROUGH THE DAY. PRECIPITATION CHANCES WILL
INCREASE ACROSS CARBON...CONVERSE AND NIOBRARA COUNTIES ON TUESDAY
AFTERNOON AS THIS AREA REMAINS ON THE WARM SIDE OF THE STRONG SW/NE
ORIENTED JET STREAK. TEMPERATURES WILL BE COOLER WEST OF THE
LARAMIE RANGE FOR TUESDAY WHILE EASTERN PLAINS WILL REMAIN WARM.
BY WEDNESDAY...THE NEXT CYCLONICALLY CURVED JET STREAK WILL NOSE
INTO COLORADO PLACING THE FAVORABLE LFQ OVER THE CWA. THIS WILL
COMBINE WITH A SURFACE COLD FRONT THAT WILL DROP SOUTH THROUGH THE
AREA DURING THE DAY. BEHIND THE FRONT...UPSLOPE FLOW ALONG WITH
THE LAGGING MID-LEVEL FRONTOGENESIS WILL COMBINE WITH OVERRUNNING
MOISTURE AND THE AFOREMENTIONED LFQ TO BEGIN TO PRODUCE MORE
WIDESPREAD PRECIPITATION ESPECIALLY DURING THE AFTERNOON HOURS.
FORTUNATELY...TEMPERATURES WILL BE WARM ENOUGH FOR PRECIPITATION
TO REMAIN ALL RAIN AT THIS POINT. THIS CHANGES IN SUBSEQUENT
PERIODS IN THE LONG TERM HOWEVER. UNSETTLED WEATHER ALONG WITH
COOLER AIR...WILL HOLD TEMPERATURES DOWN ON WEDNESDAY...WITH 40S
FOR NORTHERN AND WESTERN ZONES...AND 50S ELSEWHERE.
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...
MODELS CONTINUE TO HONE IN ON THE WED NIGHT PERIOD AS A
FAVORABLE TIME FOR WIDESPREAD PRECIP OVER THE CWA. THE GFS AND
ECMWF BOTH SHOW A STRONG SHORTWAVE MOVING OVER NORTHERN COLORADO ON
WED NIGHT WITH MOST OF THE CWA IN THE LEFT EXIT REGION OF THE 250MB
JET BETWEEN 00-12Z THURS. THICKNESSES AND SOUNDINGS SUGGEST THAT
SNOW WILL BE THE PRECIP TYPE ON WED NIGHT. PRECIP COULD START OUT
INITIALLY AS A MIX OF RAIN AND SNOW IN THE NEBRASKA PANHANDLE ON WED
EVENING...THEN TRANSITION QUICKLY TO SNOW AS COLD AIR ADVECTION
CONTINUES THROUGH THE EARLY NIGHT HOURS. MODEL QPF CONSENSUS IS IN
THE 0.25-0.50 INCH RANGE FOR THIS FIRST WAVE. SHORTWAVE AND ITS
ASSOCIATED DEEP LAYER LIFT MOVES EAST OF THE REGION ON THURS MORNING
WITH SNOW RATES DROPPING OFF. THE MODELS SHOW BROAD CYCLONIC FLOW
ON THURS WITH LLVL UPSLOPE ALONG AND EAST OF THE LARAMIE RANGE.
DROPPED HIGH TEMPERATURES ON THURS INTO THE LOW-TO-MID 30S OVER THE
PLAINS WITH CLOUD COVER...UPSLOPE...AND SNOW COVER MAKING IT
DIFFICULT TO GET MUCH WARMING. ALTHOUGH UPPER LEVEL FORCING IS WEAK
ON THURS...LLVL UPSLOPE COULD BE SUFFICIENT TO GENERATE SOME WEAK
SNOW SHOWERS/FLURRIES MAINLY ALONG THE LARAMIE RANGE.
THE NEXT STRONG SHORTWAVE IN THE CYCLONIC MIDLEVEL FLOW IS PROGGED
TO TREK FROM UTAH INTO COLORADO ON THURS NIGHT. WITH DEEP LAYER
UPWARD MOTION INCREASING ON THURS NIGHT...AND LLVL UPSLOPE ALREADY
IN PLACE...WOULD EXPECT ANOTHER ROUND OF SNOW ESPECIALLY OVER THE
SOUTHERN ZONES. NEED TO CONTINUE TO MONITOR THE TRACK OF THIS
SHORTWAVE AS A SHIFT TO THE NORTH OR SOUTH WOULD OBVIOUSLY HAVE
IMPLICATIONS ON QPF AMOUNTS. SNOW COMES TO AN END BY MIDDAY FRI
AS THE FORCING EXITS THE AREA. ANOTHER COLD DAY ON FRI WITH
TEMPERATURES AROUND 25-30 DEGREES BELOW NORMAL FOR LATE OCTOBER.
NORTHWESTERLY MIDLEVEL FLOW BECOMES ESTABLISHED OVER SOUTHEAST
WYOMING ON SAT WITH DRYING IN LOW AND MIDLEVELS. NOT GOING TO SEE
ANY BIG WARMUP UNTIL SUN...WHEN THE SFC HIGH PRESSURE OVER THE
PLAINS IS REPLACED BY A DEVELOPING SFC TROUGH AND INCREASINGLY ZONAL
FLOW ALOFT.
FIRE WEATHER...
A FAIRLY ACTIVE WEEK TAKING SHAPE ACROSS THE DISTRICT WITH BREEZY
TO LOCALLY WINDY CONDITIONS FOR AREAS ALONG AND WEST OF THE
LARAMIE RANGE FOR MONDAY AND TUESDAY FOLLOWED BY A PROLONGED
PRECIPITATION EVENT THAT WILL BEGIN AS EARLY AS WEDNESDAY
AFTERNOON AND CONTINUE INTO FRIDAY. IF CURRENT FORECASTS HOLD THIS
WILL BRING IN MUCH COLDER AIR ALONG WITH LIGHT TO MODERATE SNOW
ACCUMULATIONS. BEFORE THEN...TEMPERATURES WILL CONTINUE TO BE
UNSEASONABLY WARM TODAY AND TUESDAY WITH HIGHS THAT WILL CLIMB
INTO THE 60S AND 70S. WINDS MAY BECOME VERY STRONG ACROSS WIND
PRONE AREAS NEAR ARLINGTON AND BORDEAUX TONIGHT WITH WIND GUSTS TO
60 MPH POSSIBLE. MINIMUM RELATIVE HUMIDITIES SHOULD HOLD IN THE
20S AND 30S FOR BOTH TODAY AND TUESDAY. HOWEVER...THESE WILL
INCREASE AS COLDER UNSETTLED CONDITIONS WORK IN FOR THE LATTER
HALF OF THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING FROM 9 PM MONDAY TO 9 AM TUESDAY FOR WYZ106-
WYZ110.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...HAHN
LONG TERM/AVIATION...FINCH