AREA FORECAST DISCUSSION
NWS NORMAN OK
AFDOKC 258 PM CST TUE JAN 16 2001
RUNNING BEHIND DUE TO NUMEROUS COORD CALLS THIS AFTERNOON. LEAD
SHORT WAVE TROF CONTINUES TO SHEAR OUT AND WEAKEN AS IT MOVES NEWD
ACROSS THE AREA THIS AFTERNOON WITH THE TRAILING EDGE OF DEEPER
MOISTURE AND PRECIP FROM BUFFALO TO JUST WEST OF OKC TO ARDMORE.
PRECIP HAS BEEN A MIXED BAG SO FAR WITH VERY LITTLE ACCUMS. BEST
SNOW HAS ACTUALLY BEEN IN NC OK WHERE HEAVY SNOW BANDS HAVE REDUCED
VIS TO UNDER A MILE BRIEFLY IN PLACES. MODELS DID QUITE A BIT
BETTER THIS TIME WITH THE LOW LEVEL THERMAL FIELD AS VERIFIED BY AN
AIRCRAFT TEMP PROFILE FROM WILL ROGERS ABOUT 2 HOURS AGO. MODELS
ALSO DID A VERY GOOD JOB OF BRINGING THE MOISTURE IN INITIALLY AT
THE CORRECT LAYER ABOVE THE FREEZING LEVEL THIS TIME. LOOKING BACK
AT THE MASS FIELDS FROM YDAYS 12 RUNS..EVOLUTION TODAY HAS NOT BEEN
TOO FAR OFF FROM WHAT ONE WUD EXPECT..THE LACK OF BROAD DEEP
MOISTURE AND A TIGHTER THERMAL GRADIENT HAS THUS FAR RESULTED IN
PRETTY MUCH A NON-EVENT.
BAND 10 AND 12 WV IMAGERY STILL IS SHOWING A BROAD DRY SLOT SLOWLY
PUSHING ACROSS THE FA BEHIND VORT LOBE..AND CURRENT THINKING IS THAT
THE MAIN PRECIP WITH THIS FEATURE WILL SHUT OFF THIS EVENING IN NC
OK AS DEEPER MOISTURE IS SHUNTED NWD. HOWEVER..BROAD WEAK WAA WILL
CONTINUE..AND THIS WILL LEAD TO DRIZZLE/FLURRIES AND FOG OVER MOST
OF THE AREA THRU THE NITE. TEMPS EXPECTED TO REMAIN BLO FREEZING
ACROSS THE NRN THIRD OVERNITE..THUS MAY SEE SLICK ROADS DEVELOP EVEN
THO THE SIGNIFICANT PRECIP WILL BE OVR. WE WILL CONT THE WINTER WX
ADV IN THESE AREAS..BUT THE WARNING FOR THE NW WILL BE DOWNGRADED.
SOME HILITES MAY NEED TO BE EXTENDED FOR PARTS OF THE WEST AND/OR
SOUTH FOR WED. BUT EVOLUTION IS UNCERTIAN ATTM AND WILL LET MID CREW
DECIDE THAT COURSE OF ACTION.
NEXT VORT LOBE WILL SWING NEWD LATE TONITE/WED MORNING AND MAY SEE
PRECIP REDEVELOP OVER THE SRN ZONES AFTER MIDNITE. BEST LIFT
APPEARS TO BE FOCUSSED JUST SOUTHEAST OF THE FA AT THE NOSE OF THE
850 LLJ HOWEVER.
LATEST MODELS HAVE FLIP FLOPPED YET AGAIN AND NOW ARE FARTHER SOUTH
WITH THE SYSTEM FOR THURS AFTERNOON THRU FRI MORNING IN THE
SOUTH..LIKELY IN RESPONSE TO MORE ENERGY DIVING SWD IN THE NRN
STREAM. WILL KEEP CHANCE POPS GOING AND WORD CHANGING TO SNOW BEFORE
ENDING ON FRIDAY MORNING. NRN STREAM SYSTEM WILL BRING A CHANCE FOR
LITE SNOW TO MOST OF THE AREA FRI/FRI NITE. CLIMATOLOGICALLY THESE
NW FLOW SYSTEMS ARE PRONE TO DUMPING A FEW INCHES SOMEWHERE /SIMILAR
TO NEW YRS EVE SYSTEM/..BUT HARD TO TELL WHERE ATTM. COLD TEMPS
THRU THE WEEKEND WITH A WARMING TREND MON/TUE.
THANKS FOR COORD WITH TUL/ICT/DDC/AMA
MILLER
PRELIM NUMBERS..SUBJECT TO CHANGE..
OKC 30 33 28 34 / 80 80 40 30
HBR 31 33 27 35 / 80 80 30 30
SPS 35 37 30 35 / 80 80 30 40
GAG 22 29 22 35 / 80 80 10 10
PNC 28 32 27 35 / 80 80 30 10
DUA 37 39 35 36 / 80 80 50 50
.OUN...
OK...WINTER WX ADV WEST CENT/NW/NORTH CENT OK TONITE OKZ004>020.
TX...NONE.
AREA FORECAST DISCUSSION
NWS SEATTLE WA
AFDSEW 840 AM PST TUE JAN 16 2001
.OVERVIEW...
THE PICTURE IS MUCH THE SAME AS IT HAS BEEN OVER THE PAST SEVERAL
DAYS AS A STRONG JET DOMINATES THE MID LATITUDES OF THE CENTRAL AND
WRN PAC...AN AREA OF INTENSE CYCLOGENESIS CONTINUES BETWEEN ABOUT THE
DATELINE AND 160W AT 45N...THEN SPLITTING/DYING SYSTEMS ENCOUNTER A
PERSISTENT RIDGE OVER THE PAC NW. PER SATELLITE IMAGERY AND ACARS
DATA THE MODELS APPEAR WELL INITIALIZED ACROSS THE ERN PAC. WHILE THE
MODELS APPEAR SIMILAR TO PREVIOUS RUNS...THE 12Z MESOETA AND AVN IN
PARTICULAR ARE FASTER IN BRINGING THE REMNANTS OF THE SLUG OF
MOISTURE NOW CROSSING 140W INTO WRN WA WED AFTN/EVENING. THIS IS NOT
UNREASONABLE GIVEN WHAT IS SEEN ON IR/WATER VAPOR LOOPS.
.SHORT TERM...THE MAIN PROBLEM THROUGH MIDDAY WED WILL BE FOG AS
LIGHT GRADIENTS AND STRONG LOW LEVEL INVERSIONS PERSIST. ALTHOUGH THE
FOG TOPS ARE ONLY 1200-1500 FEET...INSOLATION IS STILL RATHER WEAK
THIS TIME OF YEAR. SO EXPECT FOG TO BE SLOW TO LIFT/BREAK...AND WILL
HAVE DIFFICULTY BREAKING IN TRADITIONALLY STAGNANT AREAS S OF KSEA IN
THE INTERIOR. LIGHT GRADIENTS...STRONG LOW LEVEL INVERSIONS...AND
RADIATIONAL COOLING WILL REPEAT THE FOG PROCESS TONIGHT THROUGH
MIDDAY WED. MESOETA FCST SOUNDINGS SHOW WARM ADVECTION FROM 5000-8000
FEET REACHING THE COAST MIDDAY AND THE INTR LATE AFTN. THIS WILL KEEP
THINGS CLOUDY WED AFTN AND PROVIDE SOME VERY LGT PCPN TO THE COAST
AND A FEW SPRINKLES IN THE INTR BY EVENING. WILL MAKE NECESSARY
ADJUSTMENTS.
.EXTENDED...WITH THE RIDGE AXIS PROGRESSING EWD INTO ERN WA...EXPECT
AN ALMOST ENDLESS STREAM OF STRETCHING SYSTEMS TO AFFECT WRN WA FRI
THRU MON WITH A CHANCE OF PCPN AND SEASONAL TEMPS IN GENERALLY
OFFSHORE FLOW. THU MAY BE THE NICE DAY OF THE BUNCH AS OFFSHORE
GRADIENTS INCREASE AHEAD OF FRI MRNGS STRETCHING SYS. CURRENT
FORECASTS THU AND BEYOND LOOK GOOD.
UIL 005 SEA 001 OLM 001 ALBRECHT
.KATX...VCP31/CSR32...OPERATIONAL
.SEW...SMALL CRAFT ADVISORY ON THE COAST FOR HEAVY SWELL.