Wednesday September 9

Past forecast verification and analysis: My 50% rain forecast was more than warranted as a surprisingly strong and virtually stalled deformation zone setup over Raleigh. Cary received around half an inch with Raleigh receiving well more than that.

Updates:

Synoptic Analysis: Partly to mostly cloudy skies will be the norm over the next few days with a slight chance of showers over night. Seasonably cool temperatures will continue over the next few days with slight modification as the week comes to an end.

Near term (12 hr):

RDU is currently located under the left exit region of an upper level jet which should provide subsidence along with decreasing clouds in the extreme near term. RDU will be near the center of the upper level low towards the end of the near term. Currrent soundings show a backing profile above at 900 mb which verifies the upper air analysis of subsiding air despite some cloudiness aloft. Expect 500 mb vort max to approach from the west this evening. This could help ignite a shower or two. Will go 20 percent just to cover myself. Any precip should remain light. Partial clearing should aid in temps reaching one cat below climatology. It will be interesting to see if the line of storms to our west hold together.

Short term ( 12 -72 hr):

RDU remains in the trough through the short term. The strength of the trough weakens a bit and then restrengthens a bit later in the period likely due to some downstream assistance (if you will) from the much stronger trough in the upper plains. A weak low pressure is predicted by the GFS to form in South Carolina, weaken and then restrengthen over the Gulf Stream. Can't rule out a chance of showers and storms Friday afternoon and evening due to this weak surface low and some weak vorticity aloft. The upper air dynamics truly are weak though. It's difficult to tell whether or not RDU is truly in the left exit region of a jet or if my eyes are just seeing things. At this time I just don't see enough evidence to warrant and pops. Will go with slightly below persistent high for tomorrow due to some weak CAA along with residual cloud cover. Air will modify a bit on Friday.

Long term (Only if a legit major system is showing up):

Forecast:

Wednesday: Decreasing clouds with a high of 81. 20% chance of showers/storms tonight low of 61

Thursday: Partly cloudy high 79 low 59

Friday: Partly cloudy high 82 low 60

Review of RAH AFD: I said we were under the LE region of a jet which leads to subsidence. Just a mental mistake on my part as the LE leads to rising air, which I knew. Just not thinking clear this morning. I need to double check myself when typing stuff up. If I ever put something like that out in public I'd get called out big time by the weather nerds.