Sunday, June 21, 2015

a wetter outlook... (am.21.jun.15)>

Skies are cloudy and very light rain is falling early this Sunday morning.  The current temperature is 61.5F (16.4C), and the humidity is 61%.  We've had a spell of heavy rain and thunder/lightning overnight -- most of it occurring between roughly 1:00 and 5:00am -- and there's 1.90" (4.8cm) in the rain gauge to show for it.  The low temp of 57.7F (14.3C) occurred during that heavy rain episode.

It's not officially the monsoon season, and it will likely be at least several days before the IMD brings that monsoon onset line into Himachal Pradesh, but 3.25" (8.2cm) of rain in the past 36 hours -- since late Friday evening -- is enough to tell us that we're on our way.  If you're a regular reader/follower, you've been keeping up with the step-by-step and day-by-day evolution of our atmosphere recently, and you're well-acquainted with the factors in play.  Basically, the atmosphere all across the Indian sub-continent is becoming more and more packed with rich and juicy tropical moisture, and that very moist air mass has been creeping north and northwestward the last few days.  At the same time, a west-northwesterly flow in the upper-levels is delivering a few minor disturbances containing slightly cooler air aloft.  This is a certain recipe for significant shower and thunderstorm development all along the front ranges of the Himalayas.  According to satellite pics and the data/charts, I still think we'll be able to come up with hours of dry weather and some sunshine from time to time, but the risk of moderate to heavy downpours will never really go away -- until perhaps the very end of the week.

A particularly strong upper-level circulation will move across our very moist air mass on Wednesday into Thursday, which concerns me that we could get a couple of periods of very heavy rainfall somewhere in our general vicinity during that time frame.  Temperatures will obviously settle into a cooler zone than we experienced most of last week, but that's what normally happens this time of year.

Follow the details on THE 7-DAY OUTLOOK and AWAITING MONSOON 2015 on tabs above.