FXUS63 KDDC 012131
AFDDDC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DODGE CITY KS
331 PM CST TUE DEC 1 2009
.DISCUSSION...
DAYS 1-2...
STRONG COLD FRONT WILL BE PUSHING THROUGH SOUTHWEST KANSAS THIS
EVENING ON A NICE ISALLOBARIC SURGE...WITH THE STRONGEST PUSH
OCCURRING FROM 03-09Z ACROSS MUCH OF THE DDC FA. MID-LEVEL HEIGHTS
WILL ALSO BE IN FREE-FALL WITH ABOUT A 60 TO 80 METER H5 HEIGHT
FALL FROM 18Z WEDNESDAY TO 06Z THURSDAY. VERY STRONG MID LEVEL
COLD ADVECTION WILL ALSO EXIST...STRONGEST OCCURRING DURING THE
DAY WEDNESDAY...WITH H5/7 TEMPERATURES FALLING TO -26/-15C
RESPECTIVELY AT KDDC. SO THIS WILL BE A DEEP, ARCTIC AIRMASS...NOT
A SHALLOW ONE. WESTERN KANSAS WILL BE AMIDST BROAD CYCLONICALLY
CURVED MID LEVEL FLOW PATTERN WITH THE CENTER OF THE VERY COLD H5
GYRE CENTERED OVER SOUTHERN MINNESOTA AT ABOUT 526 DAM.
COLD AIR WILL BE THE STORY OVER THE NEXT COUPLE OF DAYS. BOTH
WEDNESDAY AND THURSDAY WILL BE COLD WITH AFTERNOON TEMPERATURES
ONLY REACHING THE MID TO UPPER 30S...WITH PERHAPS A FEW 40 TO 42
DEGREE READINGS ACROSS BARBER AND COMANCHE COUNTIES. SUNSHINE WILL
NOT HELP MUCH EITHER, ALTHOUGH NOT MUCH SUN IS EXPECTED GIVEN THE
COLD MID LEVEL AIRMASS WITH SOME AT LEAST MEDIOCRE MID LEVEL
MOISTURE. HAVE INSERTED SOME 20 POPS ACROSS THE EXTREME WEST ALONG
THE COLORADO BORDER AS SOME LIGHT SNOW MAY DEVELOP ALONG THE H7
BAROCLINIC ZONE WEDNESDAY NIGHT INTO THURSDAY...HOWEVER ANY
ACCUMULATING SNOWFALL SHOULD REMAIN WELL TO THE WEST UP AGAINST
THE HIGHER TERRAIN OF NORTHEASTERN NEW MEXICO AND SOUTHEASTERN
COLORADO. AFTER A COLD DAY WEDNESDAY WITH NORTH WINDS IN THE 20 TO
30 MPH RANGE (EARLY)...WINDS WILL GRADUALLY SUBSIDE LATE IN THE
DAY...AND BECOME VERY WEAK DURING THE NIGHT. WITH COLD SURFACE
RIDGE AXIS ALMOST OVERHEAD ACROSS WESTERN KANSAS...ANY AMOUNT OF
CLEAR SKIES WOULD ALLOW TEMPERATURES TO PLUMMET AS DEWPOINTS WILL
BE VERY LOW. IF IT WERE TO BE CLEAR THE WHOLE NIGHT WEDNESDAY
NIGHT...LOW TEMPERATURES WILL EASILY REACH 13 TO 16F...AND THE
CURRENT FORECAST WILL REFLECT SOMETHING CLOSE TO THIS. IT WILL
MOST DEFINITELY BE THE COLDEST NIGHT OF THE SEASON UP TO THIS POINT.
ANOTHER MINOR JET STREAK WILL MOVE SOUTH DOWN THE INTERMOUNTAIN
WEST REGION...ONLY HELPING REINFORCE THE COLD DEEP LAYER AIRMASS
ACROSS THE WESTERN PLAINS. DEPENDING ON THE TIMING OF THE
SECONDARY COLD FRONTAL SURGE THURSDAY...SOME PORTIONS OF WEST-
CENTRAL KANSAS MAY NOT GET ABOVE 32 DEGREES F. THIS IS A VERY COLD
MID LEVEL AIRMASS THAT WILL BE DISPLACED RATHER FAR TO THE SOUTH
EVEN FOR THE FIRST FEW DAYS OF DECEMBER. (USUALLY IF WE SEE A MID
LEVEL COLD/LOW HEIGHT ANOMALY LIKE THIS IT HAPPENS LATER IN
DECEMBER OR IN JANUARY DURING THE HEART OF THE COLD SEASON). THIS
PATTERN ACTUALLY HAS SOME SIMILARITIES TO THE 10 OCTOBER EVENT
LAST MONTH. -UMSCHEID
DAYS 3-7...
THE 12Z EC IS NOW BEGINNING TO COME AROUND TO A SOLUTION THAT LOOKS
MORE LIKE THE OTHER EXTENDED MODELS. THERE ARE STILL CONSIDERABLE
DIFFERENCES ON SPECIFICS BETWEEN THE EC AND THE RELATIVE CONSENSUS
THAT EXISTS BETWEEN THE GFS/GEM/UKMET. HOWEVER, GIVEN THE EC TREND
TOWARD THE CONSENSUS (AS WELL AS ITS RADICAL FLIP FLOPPING OF THE
LAST SEVERAL DAYS), AM STILL LEANING AWAY FROM IT WHERE IT DIFFERS
FROM THE OTHERS. THUS GFS WAS USED FOR GRID MODS AGAIN TODAY.
THE OVERALL THEME OF THE EXTENDED PERIOD IS COLDER THAN NORMAL WITH
THE NEXT CHANCE OF PRECIP COMING IN DAY6 AND BEYOND. A FAIRLY DEEP,
COLD AIRMASS WILL REMAIN IN PLACE OVER THE PLAINS FRI AND SAT. SOME
TEMP MODERATION IS LIKELY, ESP BY SAT WHEN A LEE TROF DEVELOPS OVER
ERN COLORADO OR WRN KANSAS. AT THE SAME TIME, TWO THINGS WILL BE
HAPPENING. A LOW WILL DROP IN OVER THE PACNW AND CLOSE OFF AND A
WEAK SHORTWAVE WILL MOVE THROUGH THE NRN PLAINS. THE LATTER WILL
DRIVE A REINFORCING SHALLOW COLD AIRMASS SOUTH INTO THE CENTRAL
PLAINS SAT NIGHT. THIS WILL KNOCK OUR TEMPS BACK, POSSIBLY QUITE A
BIT SUN-TUE.
AS THE WESTERN LOW MEANDERS S AND E-WARD SUN INTO MON, ARCTIC HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL ALSO BE OOZING SOUTH. THE
RESULTING UPSLOPE FLOW OVER THE CENTRAL PLAINS IS STARTING TO LOOK
FAVORABLE FOR FREEZING DRIZZLE. THE MID LEVELS REMAIN DRY AND
MOISTURE IS CONFINED TO THE LOWEST FEW THOUSAND FEET WITH TEMPS WELL
BELOW FREEZING. THERE MAY BE A FEW BOUTS OF SNOW SUN NGT-MON AS WELL
AS S/WAVES (WITH POCKETS OF DEEPER MOISTURE) COME THROUGH THE WSW
FLOW. IT WILL TAKE A WHILE TO GET THIS GOING SO AM KEEPING SUNDAY
DRY. BUT WILL BE INTRODUCING SOME SGT CHC POPS AND A WINTRY MIX FOR
MON.
TUE IS TRICKY. ALL THE MODELS SHOW THE WESTERN CLOSED LOW EJECTING
OUT IN SOME FORM AND I FIND NO REASON TO DOUBT THAT. THE CONSENSUS
IS TO HOLD SW KS RIGHT ON THE CUSP OF COLD AIR (BUT STILL ON THE
COLD SIDE) WHEREAS THE EC PUTS US IN THE WARM SECTOR. IT IS
REASONABLE TO SAY THAT SOMEWHERE CLOSE TO US HEAVY SNOW, FREEZING
RAIN, AND RAIN WILL ALL BE POSSIBLE. I IMAGINE IT WILL BE DIFFICULT
TO MIX OUT THE SHALLOW COLD AIR AND THUS I WOULD SIDE WITH FZ
PRECIP. BUT THERE IS NO WAY TO NAIL DOWN ANY SPECIFICS FOR DAY 7, SO
WILL SIMPLY COVER WITH A CHANCE OF SNOW/RAIN. -WRIGHT
&&
.AVIATION...
VFR CONDITIONS WILL PERSIST THROUGH 24 HRS. A COLD FRONT WILL PASS
THROUGH THE TAF SITES BETWEEN 02/00Z AND 02/03Z, WITH WINDS SHIFTING
TO THE NORTH AND INCREASING TO 20-30KTS. CIGS WILL LOWER TO AROUND
050 AFTER 02/06Z BUT SHOULD NOT DROP BELOW VFR. PRECIP/VIS
RESTRICTIONS ARE NOT EXPECTED. -WRIGHT
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 27 38 18 36 / 0 0 0 0
GCK 25 37 15 32 / 0 0 0 0
EHA 25 36 17 31 / 0 10 20 20
LBL 28 38 19 34 / 0 10 10 10
HYS 25 37 16 32 / 0 0 0 0
P28 30 42 23 39 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN25/34/34
