Statewide Forecast Discussion:

Forecast Discussion
Oklahoma Weather Lab
Issued:  4:45 PM CDT Sun Sep 06 2009


...SYNOPSIS...
Satellite imagery at this hour depicted low level cyclone across portions of Missouri/northeastern Oklahoma. A weak trough evident on mid morning/later afternoon surface observations suggests weak surface trough and localized surface convergence has lead to thunderstorms across portions of southwestern and southern Oklahoma. 

...SHORT TERM...(SUN EVE-TUES)
Main issue with the short term was concern for fog across northeastern sections of the state this evening/Monday morning. Early morning hourly wx observations noted that visibilities were as poor as a forth of a mile in northeastern Oklahoma. With that said, will mention the possibility of early morning fog in HWO. NAM and GFS forecast wind fields keep the predominant flow out the southeast which should lead to an increase in low level moisture. Forecast soundings also suggest that deeper moisture (through 700MB) should result in an increase in cloudiness, therefore will increase cloud cover late Monday through Tuesday. The 12Z NAM is quite aggressive in terms of moisture as it suggests PW values near 2.0 inches across central Oklahoma. For now will follow previous shifts lead and keep slight PoPs and increase clouds on Tuesday and Wednesday. MOS guidance is fairly warm on the temperatures on Tuesday, so I will probably trim temperatures down a bit. Surface boundary was very hard to depict in forecast surface temperatures late Monday and Tuesday. HPC guidance depicts weak stationary front across southern Oklahoma. Long term forecast looks to be in good shape and no amendments were necessary for that portion of the forecast. 

...LONG TERM...(WED-FRI)
With the jet stream and any major impulses associated with it residing to the north, the state of Oklahoma should experience mostly tranquil conditions. High pressure will be present for much of the forecast period and should result in skies remaining mostly clear to partly cloudy throughout the daytime and nighttime hours. Highs will range in the mid to upper 80s throughout the northern and eastern parts of the state to the lower 90s in the western areas each day during the Sunday through Wednesday interval (per latest NAM and GFS model outputs). Lows should remain in the mid to upper 60s across eastern Oklahoma while the western areas may experience lows in the low to mid 70s range. GFS model outputs have also been hinting at the chance for precipitation across the state on Wednesday. Because of the amount of moisture and instability likely to be present across the area on Wednesday, some of the convective activity could contain heavier rains and lightning thus thunderstorm chances have been added to the extended forecasts.


Forecasters:
BAIN SQUITIERI ZWINK