Friday, July 03, 2015

Chopped-Up Setting Today

The CG flash density maps shown here (for last 24-hours above and for last 6-hours below - both ending about 6:30 am MST - illustrate that thunderstorm activity was concentrated along the Arizona/New Mexico into Mexico yesterday afternoon. During early morning hours storms extended rapidly eastward from Cochise County across Pinal and Maricopa Counties - as per post below. The flash densities are from Weather.Graphics/Vaisala.

Heavy cloud cover (visible satellite image above is from 6:45 am), as well as easterly outflows, prevail this morning across southeastern Arizona, setting up a difficult forecast situation. Clear skies and/or thin cloud cover are off to the southeast and are moving this way. But it is likely that temperatures will not warm nearly as quickly as current model forecasts indicate. The 00 and 06 UTC WRF-NAM forecasts suggested the early morning MCS, but moved the cloud shield away too quickly, so Mike's discussion of the 12 UTC WRF runs will be the more up-to-date word.

The 12 UTC TWC sounding below (from SPC) indicates a very deep cloud layer at sounding time, quite high PW, and some possible CAPE even with the warm temperatures in middle levels. However, the wind profile below below 300 mb is chopped-up, with mostly light speeds, so things are a bit of a mess. The MCV mentioned below is an unknown in the current mix, and latest NAM forecasts indicate the weak, 500 mb short-wave, also mentioned below, evolves into a small cyclone north of here during the afternoon. It may absorb the MCV and be stronger than the model forecasts. Very many "ifs" at play today and will be interesting to watch how this all sorts out.

Finally, at bottom activity has resumed in the eastern Pacific, as per the morning outlook from the NHC - however, the current disturbances of interest are well west of 110 W.

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