Area Forecast Discussion
Issued by NWS Hastings, NE

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000
FXUS63 KGID 290900
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
400 AM CDT WED JUL 29 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT WED JUL 29 2015

FOR THE MAJORITY OF THE CWA (ESPECIALLY NEB ZONES)...THIS SHOULD
BE A PRETTY STRAIGHTFORWARD NEXT 24 HOURS...WITH A CONTINUED
EXPECTATION OF DRY CONDITIONS AND SEASONABLY PLEASANT
TEMPS/DEWPOINTS...ALTHOUGH IT MAY BE A SOMEWHAT CLOUDIER DAY THAN
PREVIOUSLY THOUGHT. HOWEVER...THINGS GET A BIT TRICKIER SOUTHWARD
INTO KS ZONES (ESPECIALLY OUR BOTTOM-MOST 3 COUNTIES)...AS THERE
ARE SOME MODELS (FOR EXAMPLE THE GFS) SUGGESTING THAT THIS AREA
WILL BE BRUSHED BY THE FAR NORTHERN EDGES OF SOMEWHAT BETTER
SHOWER/WEAK THUNDERSTORM POTENTIAL THAT SHOULD MAINLY FOCUS JUST
SOUTH OF THE CWA...ESPECIALLY TONIGHT. THAT BEING SAID...OTHER
MODELS INCLUDING SIMULATED REFLECTIVITY FROM 4KM WRF/ARW RUNS
(INCLUDING THE OFTEN-RELIABLE NSSL WRF) ARE MORE SUPPORTIVE OF
THESE MEASURABLE RAIN CHANCES REMAINING JUST SOUTH OF THE
CWA...ALBEIT A RATHER CLOSE CALL. TO MAKE A LONG STORY
SHORTER...CONSIDERED ADDING A FORMAL SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS TO PARTS OF OUR KS COUNTIES FOR MUCH OF THIS
TIME FRAME...BUT GIVEN THE MIXED MESSAGES IN THE MODEL WORLD...AND
ALSO CONSIDERING THAT WE HAD BEEN CONSISTENTLY ADVERTISING A "DRY"
WEDNESDAY-WEDNESDAY NIGHT FORECAST CWA-WIDE THESE PAST FEW
DAYS...OPTED TO TAKE A "MIDDLE GROUND" APPROACH FOR NOW BY SIMPLY
INSERTING A "SLIGHT CHANCE OF SPRINKLES" INTO OUR FAR SOUTHERN
AREAS. THE INTENDED MESSAGE HERE IS THAT ALTHOUGH WE CONTINUE TO
DOWNPLAY PRECIP CHANCES...THE SPRINKLE MENTION BETTER IMPLIES THAT
CHANCES ARE NOT TRULY "ZERO" EITHER. OBVIOUSLY THE NEXT FEW SHIFTS
WILL HAVE TO MONITOR THE LATEST TRENDS JUST IN CASE PRECIP CHANCES
(POPS) AND POSSIBLY THUNDERSTORM POTENTIAL MAY NEED BEEFED UP A
BIT IN THIS TRICKY SOUTHERN AREA.

TAKING A LOOK AT THE HERE AND NOW AS OF 08Z/3AM: WE ARE ALREADY
IN THE MIDST OF A "CLOSE CALL" REGARDING SHOWER/THUNDERSTORM
CHANCES IN OUR FAR SOUTHERN CWA...AS A FAIRLY CONCENTRATED AXIS OF
SHOWERS /NON-SEVERE STORMS EXTENDING FROM NORTHEAST-CENTRAL KS IS
JUST BARELY REMAINING OUTSIDE OUR CWA FOR THE MOST PART. THIS
CONVECTION IS FOCUSED SLIGHTLY NORTH OF THE SYNOPTIC SURFACE COLD
FRONT POSITIONED OVER SOUTHERN AND EAST-CENTRAL KS...AND IS
LARGELY TIED TO AN AXIS OF LOW-MID LEVEL CONVERGENCE/FRONTOGENESIS
IN THE 850-700MB LAYER. NOT SURPRISINGLY...THE NORTHERN FRINGE OF
THIS CONVECTION IS ALIGNED ALMOST PERFECTLY WITH THE NORTHERN
FRINGES OF A VERY SLOWLY SOUTHWARD-SINKING ELEVATED INSTABILITY
AXIS...WHICH CLEARED THE VAST MAJORITY OF THE CWA BEHIND THE COLD
FRONTAL PASSAGE DURING THE PAST 24 HOURS. IN THE BIGGER PICTURE OF
THE MID-UPPER LEVELS...WATER VAPOR SATELLITE AND THE LATEST MODEL
DATA DEPICT LIMITED LARGE-SCALE FORCING OVER THE CENTRAL
PLAINS...AS THE LOCAL REGION IS SANDWICHED BETWEEN ANTICYCLONIC
FLOW ASSOCIATED WITH THE SOUTHERN PLAINS SUBTROPICAL HIGH...AND
THE SOUTHERN EDGES OF STRONGER WESTERLY FLOW ASSOCIATED WITH THE
VIGOROUS CLOSED LOW PRESSURE SYSTEM SLOWLY DEPARTING NORTHEAST
ACROSS THE MANITOBA/ONTARIO BORDER AREA. HOWEVER...THERE IS
EVIDENCE OF A SUBTLE DISTURBANCE PASSING NORTHEAST THROUGH
SOUTHWEST KS ASSOCIATED WITH A CLUSTER OF CONVECTION NEAR DODGE
CITY. WHILE 11-3.9 MICRON SATELLITE IMAGERY HAS REVEALED A LARGELY
CLEAR NIGHT THUS FAR OVER MUCH OF THE CWA...AT LEAST A THIN VEIL
OF HIGH CLOUDS IS INCREASINGLY SPREADING NORTHEAST INTO THE CWA FROM
THE SOUTHWEST KS CONVECTION. AT THE SURFACE...THINGS ARE LARGELY
PLAYING OUT AS EXPECTED TONIGHT...WITH THE SOUTHEASTERN REACH OF
BROAD HIGH PRESSURE CENTERED OVER THE NORTHERN ROCKIES PROVIDING
VERY LIGHT/MAINLY NORTHERLY BREEZES TO THE LOCAL AREA. THIS HIGH
PRESSURE AXIS...COMBINED WITH THE WELCOMED PRESENCE OF NOTICEABLY
DRIER AIR MARKED BY DEWPOINTS MAINLY IN THE 50S...HAS ALLOWED
TEMPS TO FALL SLIGHTLY BELOW LATE-JULY NORMALS IN MOST
AREAS...AND ULTIMATELY EXPECT OVERNIGHT LOWS TO RANGE FROM MID 50S
NORTHWEST...NEAR 60 CENTRAL AND MID-60S SOUTH.

NOW LOOKING AHEAD FORECAST-WISE:

EARLY THIS MORNING (THROUGH 7AM): OTHER THAN A CONTINUED GRADUAL
INCREASE IN HIGH CLOUDS SPREADING IN FROM THE SOUTHWEST...LITTLE
CHANGE FROM THE CURRENT SITUATION EXPECTED. GIVEN THAT IT APPEARS
THAT THE EXTREME SOUTHERN FRINGES OF THE CWA WILL CONTINUE TO
BARELY MISS OUT ON THE CENTRAL-NORTHEAST KS CONVECTION...WILL BE
REMOVING THE PREVIOUSLY-EXISTING SLIGHT CHANCE OF SHOWERS/STORMS
IN OUR FAR SOUTH FOR THE PRE-DAWN HOURS.

TODAY (7AM-7PM): SEE THE OPENING PARAGRAPH ABOVE FOR THE BASIC
REASONING BEHIND INTRODUCING SPRINKLE POTENTIAL INTO OUR FAR
SOUTHERN CWA IN KS. HOWEVER...BARRING AN UNEXPECTED NORTHWARD
SHIFT IN THE ONGOING EARLY MORNING CONVECTION IN CENTRAL KS...PLAN
ON MAINTAINING A THUNDERSTORM-FREE FORECAST GOING FORWARD INTO THE
OFFICIAL DAYTIME FORECAST PERIOD. AGAIN...FOR THE MAJORITY OF THE
CWA (ESSENTIALLY NEB ZONES)...CONFIDENCE IS STILL HIGH ENOUGH IN A
DRY DAY TO PRECLUDE EVEN A SPRINKLE MENTION. THAT BEING SAID
THOUGH...THE LAST FEW HRRR RUNS ACTUALLY DO TRY TO DROP A FEW
SPRINKLES OUT OF AN INCREASING MID LEVEL CLOUD DECK...BUT WILL
LARGELY IGNORE THIS FOR NOW WITH VERY LITTLE SUPPORT FROM OTHER
MODELS AND GIVEN THAT THIS LIMITED MOISTURE IS LARGELY AT/ABOVE
600MB. IN THE MID-UPPER LEVELS...SEASONABLY STRONG WESTERLY FLOW
PERSISTS OVERHEAD...WITH HINTS OF A SUBTLE DISTURBANCE PASSING
THROUGH THE CWA...POSSIBLY INCLUDING THE REMNANTS OF THE
AFOREMENTIONED SOUTHWEST KS ONE. MEANWHILE...THE NORTHERN EDGES
OF THE ELEVATED INSTABILITY AXIS OVER KS SHOULD LARGELY STALL OUT
JUST SOUTH OF THE CWA IN A WEST-T0-EAST FASHION. ALTHOUGH DO NOT
HAVE A GREAT FEEL FOR CLOUD COVER TODAY...BEEFED UP SKY COVER
PERCENTAGES SOLIDLY INTO PARTLY CLOUDY TERRITORY MOST AREAS FOR
MOST OF THE DAY...AND THERE COULD EASILY BE PERIODS OF MOSTLY
CLOUDY TOO...ESPECIALLY IF THE NAM IS CORRECT IN DEPICTING A
FAIRLY WIDESPREAD COVERAGE OF MID-HIGH CLOUDS DEVELOPING IN
RESPONSE TO THE AFOREMENTIONED WEAK DISTURBANCE(S) PASSING
THROUGH. AT THE SURFACE...BROAD HIGH PRESSURE WILL PASS EASTWARD
OVER THE HEART OF THE CWA...PROMOTING NOT ONLY LIGHT BREEZES THAT
WILL LARGELY AVERAGE UNDER 10 MPH...BUT ALSO A GRADUALLY VARYING
DIRECTION AS MANY PLACES SEE A TRANSITION FROM NORTHERLY TO
EASTERLY TO SOUTHERLY BY LATE IN THE DAY. TEMP-WISE...WOULD NOT BE
SURPRISED IF INCREASING CLOUDS HOLD THINGS BACK A TOUCH AND DID
DROP SOME AREAS (INCLUDING TRI-CITIES) 1-2 DEGREES FROM PREVIOUS
FORECAST...BUT OVERALL STILL CALLING FOR MOST OF THE CWA TO TOP
OUT IN THE 82-85 RANGE...WHICH COMBINED WITH LIGHT WIND AND
DEWPOINTS LARGELY IN THE 50S SHOULD MAKE FOR A VERY COMFORTABLE
LATE JULY DAY.

TONIGHT (7PM-7AM): AGAIN...SEE OPENING PARAGRAPH FOR FURTHER
INSIGHT INTO THE DECISION TO ADD SPRINKLE POSSIBILITY INTO PARTS
OF KS ZONES. ALTHOUGH MODEL DISCREPANCY CONTINUES REGARDING
NORTHERN KS PRECIP POTENTIAL...ITS WORTH NOTING THAT THE VERY
LATEST 06Z NAM HAS BACKED OFF THE NORTHWARD EXTENT OF
SHOWER/THUNDERSTORM POTENTIAL...NOW KEEPING OVERNIGHT CONVECTION
JUST SOUTH OF THE CWA (MUCH THE SAME PLACEMENT AS THE ONGOING
ACTIVITY). IN THE MID-UPPER LEVELS TONIGHT...FLOW OVER THE CWA
STARTS TO TURN EVER-SO-SLIGHTLY NORTHWESTERLY...IN RESPONSE TO
THE SOUTHERN PLAINS RIDGE STARTING TO RETROGRADE WESTWARD A BIT.
WHILE FAIRLY SUBTLE LOW-MID LEVEL LIFT/CONVERGENCE IS EXPECTED TO
PROMOTE "SOME" COVERAGE OF SHOWERS/STORMS MAINLY JUST SOUTH OF THE
CWA...THE VAST MAJORITY OF THE LOCAL AREA SHOULD REMAIN VOID OF
EVEN SPRINKLES...WITH A LIKELY DECREASE IN MID-HIGH LEVEL CLOUDS
AS WELL FROM THE DAYTIME...THUS PROMOTING MOSTLY CLEAR SKIES
ESPECIALLY NORTH OF THE STATE LINE. AT THE SURFACE...LIGHT BREEZES
WILL CONTINUE IN THE PRESENCE OF BROAD HIGH PRESSURE...BUT LIKELY
TAKING ON MORE OF A SOUTHERLY AND/OR WESTERLY COMPONENT. ALL IN
ALL...LOW TEMPS ACROSS MOST OF THE CWA MAY END UP BEING VERY
SIMILAR TO THOSE OBSERVED THIS MORNING...BUT FOR NOW WILL AIM MOST
PLACES VERY SLIGHTLY WARMER...WITH MOST OF THE CWA BOTTOMING OUT
SOMEWHERE IN THE 58-63 RANGE.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 400 AM CDT WED JUL 29 2015

AFTER A VERY NICE WEDNESDAY WE WILL WARM RIGHT BACK UP INTO THE
UPPER 80S TO LOWER 90S FOR THURSDAY THROUGH THE WEEKEND AND INTO
NEXT MONDAY...BEFORE PERHAPS ANOTHER COOL DOWN NEXT TUESDAY. WE DO
HAVE SEVERAL RAIN CHANCES...BUT CONFIDENCE IN SEEING PRECIPITATION
IS NOT THAT HIGH ON ANY GIVEN DAY. MOST LOCATIONS WILL LIKELY END UP
DRY THROUGH FRIDAY...BUT WE WILL SEE AT LEAST A FEW MORE CHANCES OF
RAIN THEREAFTER.

THURSDAY AND FRIDAY...THE HUMIDITY WILL BEGIN TO WORK BACK INTO THE
REGION. DEWPOINTS WILL RISE FROM THEIR LOW POINT IN THE LOWER 50S
TODAY...TO AROUND 60 ON THURSDAY...AND INTO THE MID 60S BY FRIDAY.
THE SFC WIND WILL BE FAIRLY LIGHT...BUT IS EXPECTED TO BECOME
GENERALLY SOUTHERLY...WHICH WILL HELP TO WARM THINGS UP A COUPLE
DEGREES BACK TO AROUND NORMAL IN THE UPPER 80S TO AROUND 90. THE
UPPER RIDGE OVER THE SOUTHERN PLAINS WILL RETROGRADE BACK TO THE
WEST AND SET UP OVER THE DESERT SOUTHWEST. IN OUR AREA THERE WILL BE
AN AREA OF WEAK SFC CONVERGENCE ACROSS OUR NORTHERN AND EASTERN
ZONES FRIDAY AFTERNOON THAT COULD POP A FEW ISOLATED THUNDERSTORMS
BASED ON THE 00Z NAM AND 00Z GFS. CONFIDENCE IS LOW AND CONVECTION
WOULD LIKELY BE VERY HIT AND MISS WITH MOST FOLKS LIKELY MISSING OUT
ON IT.

SATURDAY THROUGH MONDAY...NORTHWESTERLY FLOW ALOFT WILL SEND US A
FEW SHORTWAVES AND SUBSEQUENT THUNDERSTORM CHANCES. ONE SUCH
SHORTWAVE IS EVIDENT IN THE 00Z GFS AND 00Z ECMWF SATURDAY
AFTERNOON/EVENING. THEREFORE...WILL THROW SOME CHANCE POPS IN THE
FORECAST WITH THE HIGHEST POPS BEING ACROSS NORTHERN AND EASTERN
ZONES. OVERALL...AT LEAST THE WAY IT LOOK RIGHT NOW...PRECIPITATION
CHANCES WILL STILL BE FAIRLY LOW AT LESS THAN 50/50. WE SHOULD BE IN
BETWEEN SHORTWAVES ON SUNDAY SO CONFIDENCE IN DRY WEATHER IS FAIRLY
GOOD FOR SUNDAY. THE NEXT SHORTWAVE ENTERS THE PICTURE ON MONDAY BUT
FORECAST MODELS DIFFER ON THE SPEED OF THE ASSOCIATED FRONT. GIVEN
THE EXPECTATION OF HAVING SOME UPPER LEVEL SUPPORT IN THE GENERAL
AREA FROM THIS UPPER WAVE...WILL CALL FOR CHANCE POPS. TEMPERATURES
WILL REMAIN NEAR NORMAL DURING THIS STRETCH...OR GENERALLY IN THE
UPPER 80S TO LOWER 90S.

TUESDAY...CONFIDENCE IS PRETTY LOW THIS FAR OUT GIVEN THE
NORTHWESTERLY FLOW REGIME. THEREFORE...WILL STICK WITH THE
SUPERBLEND OF ALL MODELS...WHICH GIVES US A SMALL CHANCE OF
PRECIPITATION AND SLIGHTLY COOLER TEMPERATURES WITH HIGHS IN THE MID
TO UPPER 80S.

&&

.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1236 AM CDT WED JUL 29 2015

COMPARED TO THE PAST 24 HOURS...SHOULD BE A CONSIDERABLY MORE
"STRAIGHTFORWARD" UPCOMING 24 HOURS IN THE AVIATION DEPARTMENT.
FIRST OFF...NOT ANTICIPATING ANY PRECIPITATION/THUNDERSTORMS.
CONFIDENCE IS ACTUALLY VERY HIGH IN VFR CEILING...ALTHOUGH MUCH
OF THE LATTER HALF OF THE PERIOD COULD FEATURE SOME CONSIDERABLE
MID-LEVEL CLOUD COVER. VISIBILITY-WISE...CONFIDENCE IS ALSO
RATHER HIGH IN VFR...BUT THERE DOES APPEAR TO BE THE SLIMMEST
POSSIBILITY FOR A BRIEF PERIOD OF MVFR EARLY THIS MORNING IN
LIGHT HAZE...SO AT LEAST HINTED AT THIS WITH A "6SM BR" MENTION.
AS FOR SURFACE WIND...THE VAST MAJORITY OF THE PERIOD SHOULD
FEATURE SPEEDS AT/BELOW 6KT...AND WITH A HIGH PRESSURE AXIS
CENTERED OVER THE REGION...DIRECTION WILL BE RATHER VARIABLE IN
NATURE.


&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...PFANNKUCH


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