We're continuing to monitor incoming model data and the observational network as this strong storm system to our west draws closer to the region. The next 48 hours may provide several rounds of strong to severe storms across portions of the state including the potential for large hail, damaging winds, and tornadoes. There be a slight chance of severe storms forming this afternoon and evening well east of the dry line across eastern OK that may also be severe with all modes of severe weather possible. The environment may be conducive to a few large long track tornadoes late Saturday afternoon and evening across central OK into central Kansas.
The last two runs of the NAM indicate some convective development possible well east of the surface dry line which will be located across the far western part of the state this afternoon. Because the central and eastern part of the state will be in the warm sector this afternoon, increasing low level moisture will allow for increasing convective and potential energy across the area. A layer of warm air aloft, the cap, may suppress storm activity for the day, but a few showers or storms may attempt to form later this afternoon or early evening. Some may form near the I-35 area late this afternoon. If this occurs, some overnight showers and storms may occur across far NE OK into NW Arkansas.
The big upper level system will spread the strongest forcing across the state Saturday evening into overnight Sunday. As the forcing arrives Saturday afternoon, the dry line will be moving closer to west central OK. Scattered super cell storms will attempt to form and then move rapidly northeast with time capable of producing very large hail, damaging wind, and possibly long track tornadoes. The SPC (Storm Prediction Center) has upgraded the day2 Moderate Risk to a High Risk of severe weather for much of central OK into the early evening hours including the potential for a regional tornado outbreak. The actual coverage of storm activity remains a mystery. Operational model data does not model a high number of storms which suggest the capping issues may be very strong Saturday afternoon or early evening. But the parameters of the system have prompted the SPC to include the potential for a high end severe weather event Saturday evening across the high and moderate risk areas. The following is a paragraph from the SPC regarding the issues with the model data. ( The SPC uses ALL CAPS for all of their text products)
"THE MAIN CONCERN FOR THIS FORECAST IS CONVECTIVE COVERAGE. MANY OF
THE MODELS DO NOT DEVELOP NUMEROUS THUNDERSTORMS ALONG THE DRYLINE.
IN SPITE OF THIS...THE MODELS DIMINISH THE CAP ACROSS THE SRN AND
CNTRL PLAINS LATE SATURDAY AFTERNOON SO THIS BRINGS THE MODELS INTO
QUESTION. IN ADDITION...THE MODELS DRIVE A BAND OF LARGE-SCALE
ASCENT ACROSS CNTRL KS DURING THE EARLY EVENING SUGGESTING MANY
STORMS SHOULD INITIATE WITH STORMS INITIATING SWD WITH TIME EARLY
SATURDAY EVENING AS THE LOW-LEVEL JET STRENGTHENS. THESE FACTORS
COMBINED WITH SFC DEWPOINTS IN THE LOWER TO MID 60S F AND VERY
FAVORABLE LOW-LEVEL SHEAR PROFILES SHOULD PRODUCE AND ENVIRONMENT
FAVORABLE FOR A TORNADO OUTBREAK. AFTER COLLABORATION WITH WFOS
WICHITA...NORMAN...TOPEKA...TULSA AND DODGE CITY...A HIGH RISK WILL
BE ISSUED DUE TO THE POTENTIAL FOR A HIGH-END LIFE THREATENING EVENT
ACROSS THE SRN AND CNTRL PLAINS."
The upper air profile will allow the storms to consolidate into a line or several line segments of storms overnight into Sunday morning. Embedded tornadoes will be possible along with damaging winds. The main upper level forcing will be moving into the Midwest by Sunday afternoon and the thunderstorm threat will be moving away from our area into Western Arkansas, SE OK, East Texas, and southwestern Missouri. Most operational data now supports the system exiting the region Sunday midday or early afternoon. Mild and dry weather will be likely Monday into Wednesday of next week.
Severe weather is a normal occurrence during the spring and fall seasons in Oklahoma. Tornadoes are a common feature along with large hail and damaging winds. This weekend's set up, however, is a pattern to follow closely and carefully. Please remain aware of weather surroundings this weekend just in case severe weather approaches your area. We encourage everyone to have a severe weather safety plan in place, not only for this weekend, but for any adverse weather that approaches during our active weather periods of the year. It's also a good idea to have several ways of receiving weather warnings that are issued by the National Weather Service. A NOAA weather radio is a good idea. Smart phones, IPADS, and computers with battery backups are another possibility.