Convective Addiction

Vernal Bliss = Chasing Prospects on the Horizon?

Posted on 14. Mar, 2011 by Jesse in Uncategorized

The vernal equinox will usher in the first official day of spring next Sunday when the sun crosses the true celestial equator.  The days are slowly getting longer and the northern hemisphere will soon be engulfed in more widespread, seasonal temperatures.  The medium and long-range numerical models are hinting at a more favorable synoptic pattern from severe weather as we move closer to the equinox next weekend.  It’s simply too early to get into specifics, but it does appear that a more southwesterly flow pattern will entrench itself across the Midwest by late week, with several perturbations, some strong, embedded in the mid-level flow as several troughs move ashore this weekend into next week.

ECMWF (orange) vs. GFS (aqua) 500 mb forecast height profiles through next weekend

Also, both the long-range ECMWF and the GFS, along with the recent runs of the NAM, are hinting that the Gulf of Mexico should reopen for business during this time frame.  While there are some rather substantial differences among the numerical models with respect to timing, placement and tilt of the troughs, along with the depth and extent of poleward moisture return, it does appear that surface dewpoints AOA 55 degrees should begin to surge north of the Red River Valley by Thursday, and that looks to remain the case into the middle of next week, when another system should at least briefly scour the better moisture and confine it to the areas more directly proximal to the Gulf of Mexico.

Monday's 12z GFS is hinting at decent moisture return.

As this weekend and next week’s systems become better organized and model accuracy improves as we approach the short-range time frame, we’ll offer more salient thoughts on what could be one of the first “notable” chases of the year.

JLR