Expect windy and warmer air today with highs in the lower 80s.
Yet another super great weather day was observed yesterday across the state and more so across Eastern OK with afternoon highs near 70. A surface ridge of high pressure was directly overhead allowing for light winds, clear sky, and dry air. This combination is rare for a spring day, and it will not be repeated today or tomorrow or for the rest of the week.
Our surface ridge is sliding eastward while a new upper level system is developing off the west coast. This new upper level trough will be reaching the central plains by late this week but a series of interesting weather features will occur before hand. A mid-level ridge to our west will be expanding today and tomorrow while a surface trough of low pressure will allow for gusty south to southwest winds today and tomorrow. The combination of these features will drive our daytime highs well above the seasonal average with readings today in the lower 80s and Wednesday afternoon highs in the mid or upper 80s. Some locations across western OK may hit the lower 90s Wednesday afternoon with strong southwest winds.
Short term model data supports about a 10% mention for an isolated storm late tonight and early tomorrow across northeastern OK. The upper air flow will remain from the northwest today and tonight. I don't think I'll include this probability in the main graphics package today, but it's worth a mention at times.
Despite the southwest veering component of the wind, most available model data support an increase in low level moisture soon with dew points in the 60s reaching the area by late this week. As the main upper level system approaches, a surface boundary will be oscillating near the Northern OK and southern Kansas state line for a few days. The EURO is attempting to bring this boundary southward into the state Thursday with some thunderstorm activity on the cool side of the boundary, while other operational plots keep the front more northward and the area dry. A layer of warm air aloft, The CAP, will more than likely be present in the warm sector keeping most of the thunderstorm activity off the radar scope.
As the weekend progresses the front should finally get a shove and move southward Saturday bringing cooler air Sunday with the chance of some overrunning precipitation Sunday into early Monday.
The severe weather threat this weekend could be substantial but most data support the cap remaining stout across the warm sector for most of the event. If this is the case, our probability will remain low. If the cap breaks, our severe chances will increase dramatically with all modes of severe weather possible.
Yesterday's snow in Pennsylvania and the East:
Snow is mid to late April seems totally out of place, even for places like Penn and New York. And while this is true from a normal climate stand point; there have been later snowfall for the folks in Penn.
A quick and non-exhaustive search of snow records for the state of Pennsylvania indicate snow as late as June in 1954 and also in June from the year 1902. This piqued my interest for our snowfall records in Tulsa. A quick searched revealed our latest snow in Tulsa occurred April 18, 1953. The latest snowfall for OKC is slightly later with two dates, both from April 30 of 1949 and 1907.