Well, it is now 3pm and we have yet to get out of the teens. It is currently 17F at the airport, which is down a degree since the last hour, and all signs are that temperatures will stay in this range through sunset. This means that the NWS forecast has busted by at least 5-8 degrees today (they
were calling for 25-26F but revised it down to 23F earlier this afternoon). Now it looks like the NWS is going to bust again tonight too. For some unknown reason they are only forecasting 17F for our low tonight, but considering that is our
current temperature I think their forecast is way too warm. Based on the 3pm dewpoints (below zero) and the fact that we still have north winds blowing (continuing CAA), I think somewhere in the range of 10-15F is a better forecast. The NWS forecast is also looking bustable the next few days too. They are predicting that we get up to 32-33F tomorrow and 37-40F by Wednesday. I have some serious doubts that those numbers will verify. We shall see...
EDITED TO THE INCLUDE THE LATEST AFD:AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
322 PM CST MON DEC 15 2008
.AVIATION...WINDS WILL DIP UNDER 12 KNOTS AS COLD ADVECTION
CEASES...AND WINDS SWING AROUND TO EAST/SOUTHEASTERLY WITH THE
PASSING OF A RIDGE AXIS. EXPECT CEILINGS TO LOWER OVERNIGHT AND
TUESDAY MORNING WITHIN RETURN FLOW ABOVE THE SURFACE. DISTINCT
POSSIBILITY THAT INCREASED LIFT WITHIN LOW CLOUD DECK WILL
GENERATE LIGHT ICE PELLETS OR FREEZING DRIZZLE DURING DAY TUESDAY
FROM SPS-LAW-OKC/OUN.
.DISCUSSION...LIGHT WINTRY PRECIP AND SHALLOW COLD AIR PRESENT
NUMEROUS CHALLENGES BETWEEN TONIGHT AND FRIDAY. ARCTIC COLD DOME
WILL MAINTAIN ITS GRIP...WITH 1040 MB HIGH SLIDING JUST TO OUR
NORTH. MID LEVEL FRONTOGENESIS IS RESPONSIBLE FOR THE WIDESPREAD
VIRGA OVER NORTHERN OKLAHOMA...BASES AROUND 8 TO 9 THOUSAND FEET.
FORCING SHOULD WEAKEN AS SHORTWAVE RIDGE DEVELOPS ALOFT
TONIGHT...AND GIVEN THE EXTREMELY DRY LOW LEVELS WE WILL STICK WITH
NO POPS COMPARED TO HIGH CHANCE POPS FORECAST BY MAV MOS.
OUR ATTENTION WILL TURN BACK TO THE SOUTHEAST...HOWEVER...AS LOWER
LEVEL MOISTURE STARTS TO RETURN...RESPONDING TO PRESSURE FALLS OUT
WEST. MODEL QPF IS SPORADIC AND LIGHT FROM LATE NIGHT THROUGH THE
DAY ON TUESDAY...BUT THE COLD SURFACE TEMPERATURES ARE CAUSE FOR
CONCERN. MODEL SOUNDINGS INDICATE LOW OVERCAST DEVELOPING IN THE
925-850 MB LAYER. A LOW LEVEL JET WILL STRENGTHEN UP TO 40 KNOTS
DURING THE DAY...GENERATING SOME TURBULENCE IN THE CLOUD LAYER...AND
WILL LIKELY RESULT IN SOME LIGHT FREEZING RAIN OR SLEET. BEST CHANCE
APPEARS TO BE ALONG/EAST OF WICHITA FALLS TO LAWTON AND OKC AROUND
MIDDAY. IF THE EVENT IS DOMINATED BY FREEZING RAIN RATHER THAN
SLEET...THEN A SHORT FUSE ADVISORY MAY BE NEEDED FOR THE ANTICIPATED
IMPACTS ON TRAVELERS. THE OUTCOME MAY NOT BE APPARENT UNTIL THE
EVENT BEGINS. IT SHOULD BE OVER AS QUICKLY AS IT STARTS...THOUGH...
WITH THE LLJ VEERING AND CLOUD LAYER THINNING.
TUESDAY NIGHT ANOTHER FRONT WILL DROP INTO NORTHERN AND WESTERN
OKLAHOMA. IT SHOULD BE DRY EVERYWHERE INITIALLY...BUT FRONTOGENESIS
WILL AGAIN INCREASE WITHIN THE RIGHT REAR OF A SIGNIFICANT JET
STREAK. THE NAM HAS BEEN CONSISTENT IN SHOWING A STRIPE OF
PRECIPITATION ALONG AND NORTH OF THIS FRONT...ESPECIALLY ON
WEDNESDAY...SO WE MAINTAINED THE CHANCE POPS IN THAT AREA. HIGHER
ODDS FOR MORE WIDESPREAD PRECIP ARE EXPECTED WEDNESDAY NIGHT INTO
THURSDAY...WHEN A SHORTWAVE TROUGH WILL EJECT FROM THE SOUTHWEST
STATES AND INTERACT WITH A BIT DEEPER GULF AIR OVERRIDING THE COLD
DOME. WE STRONGLY SUSPECT THE GFS AND EVEN ECMWF ARE TOO QUICK TO
ERODE THE COLD AIR...AND GENERATE TOO STRONG A SURFACE LOW IN WHAT
SHOULD BE A STATICALLY STABLE AIRMASS. THE NAM IS PROBABLY
CLOSER...AS IT MAINTAINS HIGHER SURFACE PRESSURE AND MORE EASTERLY
RATHER THAN SOUTHERLY FLOW. THIS WILL KEEP THE FREEZING LINE FARTHER
SOUTH FOR A LONGER DURATION...LEADING TO ANOTHER POSSIBILITY OF
LIGHT FREEZING RAIN OR SLEET FROM WEDNESDAY NIGHT INTO THURSDAY.
ONCE THE WAVE SCOOTS BY...IT IS POSSIBLE THAT WRAPAROUND NORTHERLY
FLOW AND LOW CLOUDS WILL MAKE FRIDAY CHILLY IN SOME AREAS AS WELL. A
BRIEF RECOVERY IS THEN IN ORDER UNTIL ANOTHER STRONG COLD FRONT
ARRIVES LATER IN THE DAY ON SATURDAY. CHANGES TO THE GRIDDED
FORECAST WERE BASED PRIMARILY ON THE NAM OUT THROUGH THURSDAY. NO
CHANGES IN THE EXTENDED.
Their AFD is great and is quite detailed, but their actual forecast still makes little sense. Another front moving in on Tuesday night, yet getting warmer at the same time? Possible freezing rain/sleet band setting up over central Oklahoma tomorrow, yet only a 20% chance of precipitation forecasted? It just seems a bit odd to me.