Tuesday, June 23, 2015

threats and concerns... (pm.23.jun.15)>

Tuesday's stats:

Low temp: 59.5F (15.3C)
High temp: 74.3F (23.5C) -- updated @ 8:14pm
Rainfall since 7:00am: trace
24 hour rainfall: 0.10" (3mm)

There's a broken layer of mid-level cloudiness overhead this evening, but we're getting some nice glimpses of sunshine anyway.  Most of today's fresh thundershower development has been occurring to our south and east, leaving us with a day dominated by clouds -- though we have had some of these peeks of sunshine here and there.  There were even some traces of fog trying to develop during the mid-afternoon, just as I had noticed the humidity reading spiking at 70%... though it didn't last long.  There have been only some random and fleeting sprinkles of rain today.

We are poised right on the brink of a very interesting 48-60 hour period of weather, as several features converge on Himalayan north India.  The very latest data coming out, which I've just sifted through, is showing a more rapidly moving system, and also one that could focus the very heaviest rainfall just to our east.  It could be a fluke in the data, or it could be a trend -- we'll have to watch it.  At any rate, a rather strong upper-level disturbance is dropping southeastward from central Asia, containing some unusually cool air for late June.  Simultaneously, a low pressure circulation over the northern Arabian Sea will be heading toward the northeast.  AND -- the deepest and richest batch of tropical moisture of the season will continue to creep in from the southeast.  All of this puts us pretty close to the target zone for some very heavy rain and thunderstorms to develop during the next 12 to 24 hours, which could last into mid-day Thursday at the earliest, or mid-day Friday at the latest.  Again, as is usually the case with a complex system like this, computer models are showing some very divergent solutions... but there will definitely be the heaviest rainfall totals that we've seen since last year's monsoon season somewhere across Himachal into Uttarakhand by Friday.

A drying and warming trend will kick in by late Friday, with only a risk of an isolated mainly PM thundershower over the weekend.  But this time of year the moisture doesn't stay away for long, so periods of rain and thunder will be back in the forecast by Monday and Tuesday of next week.

Check tabs above for THE 7-DAY OUTLOOK and AWAITING MONSOON 2015.