Bit Better Today But Not Great

Brief Discussion Sunday am 11 July 2010

Yesterday – Again mostly weak and warm-top convection with best storms and rain amounts up at high mountain locations. Of the regular reporting stations, Douglas had thunder and 0.13” and several other stations had lightning or thunder but at most a trace of rain – appears that sprinkles during the night brought a trace here at house. Several RAWS stations had rainfall – Mt. Graham 0.53” and Mt. Hopkins 0.47” – the ALERT network shows rain at 24 of 93 stations during past 24-hours (with 0.55” at Mt. Lemmon and 0.47” at Rincon Creek); again the rainfall occurred mostly at the higher elevation ALERT sites.

This Morning and Today – Very moist and with light surface winds this morning. The GoC moisture surge passed Yuma at about midnight last night (see KYUX VAD above) and extends to about three thousand feet (good call Pat H.). The remnants of TD-02 appear to be spinning south of the New Mexico bootheel (see El Paso radar above) this morning, with deep convection in the core. Values of PW are very high across all of southern Arizona with amounts from upper 30s to around 45 mm – so no shortage of moistur, as per last couple of days. Warm inversion aloft has been beat down by three days of warm-top convection and there is CAPE (not great) at low elevations and much better CAPE at high elevations – definitely should be some cold-top storms around later today. The TWC sounding (bottom figure) indicates we’ve got a very chopped-up wind profile. The strongest winds are north to north-northeasterly but down between 600 and 700 mb and winds above 400 mb are southwesterly – steering flow unclear, and storms will probably propagate wherever they want to. Looks like heavier rains possible today. This morning’s NAM shears old TD-02 out stretching it from northern GoC to south-central New Mexico by evening – however, current satellite loops seem to indicate the core is moving to the northeast toward El Paso. The NAM keeps best rainfall to south along the borderlands, but some mountain storms will probably come down into lower elevations, so it’s a bit of a coin-flip for us lowlanders today. Certainly not a very great situation toda, but probably the best setup of the summer to-date.