STP 09-29-2016: Return of Showers/Thunderstorms to Western Colorado

Issue Date: Thursday, September 29th, 2016
Issue Time: 9:00 AM MDT

Summary:

As the upper-level low shifted northward out of the desert southwest and into the Great Basin, subtropical moisture made a return to western Colorado. This moisture fueled isolated-to-scattered showers/thunderstorms beginning during the afternoon hours yesterday and continuing through this morning. Most of the activity has been in the form of showers, producing mainly light rain and gusty winds. A couple of embedded thunderstorms developed late last night/early this morning as a disturbance moved northward along the CO/UT border, enhancing precipitation. No flash flooding was reported, nor have there been any hail/wind reports. Isolated-to-scattered showers and an isolated thunderstorm or two will continue through the morning hours.

For a statewide look at 24-hour precipitation totals, please take a look at the Storm Total Precipitation map below.

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Storm Total Precip Legend

FTB 09-28-2016: A Few Showers/Thunderstorms Return

Issue Date: 9/28/2016
Issue Time: 9:12 AM

NO FLOOD THREAT IS FORECAST.

The upper-level ridge that was largely responsible for the recent stretch of pleasant weather will remain in control of the forecast across eastern Colorado, keeping dry conditions present for another day. A few mid-/high-level clouds, mainly along/near the mountains, will be noted, but that’s it. On the other hand, changes are afoot for the High Country and Western Slope in the form of a slowly moving upper-level low. It is easy to pick out the low in the infrared imagery below, as well as the associated subtropical moisture plume. As the low lifts northward, mid- and upper-level moisture will stream into the state, bringing an increase of mid-/upper-level clouds to western regions.

ir_20160928

A few showers and isolated thunderstorms are expected across the Southwest Slope, San Juan Mountains, Grand Valley, and Central Mountains regions this afternoon and evening, with a couple spotty showers continuing overnight over the higher terrain. Rain rates are expected to remain well below flash flood thresholds, thanks in part to the low-levels remaining fairly dry. For more details, including rain rates and timing, please see the zone-specific forecast discussions below.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below (hover over threat areas for more details). For Zone-Specific forecasts, jump below the map.

Flood Threat Legend

Zone-Specific Forecasts

Urban Corridor, Palmer Ridge, Northeast Plains, Raton Ridge and Southeast Plains:

Mostly sunny skies and dry conditions will be the main weather story again today, leading to another pleasant late-September day. Highs over the eastern plains will be a few degrees cooler than yesterday, with other regions experiencing highs similar to those yesterday.

Front Range, Southeast Mountains, and San Luis Valley:

Dry conditions will be the main story again today, along with a slight increase of mid- and high-level clouds (as compared to yesterday). High temperatures will be similar to yesterday’s readings, as well.

Northern Mountains, Northwest Slope, San Juan Mountains, Southwest Slope, San Luis Valley, Central Mountains, and Grand Valley:

Increasing clouds and dry for most, with a few showers/isolated thunderstorms expected across western Colorado. The higher terrain of the Southwest Slope and San Juan Mountains regions will see the most activity, relatively speaking, with only isolated showers/thunderstorms over the higher terrain of the Central Mountains. As the day turns to night, a few showers will spread to the Northwest Slope and western extents of the Northern Mountains regions.

Dry low-levels will subdue rainfall rates/totals, resulting in maximum rain rates of 0.15-0.30 inches/hour, with most rain rates checking in below 0.10 inches/hour.

Timing: Noon – 9 PM, with a relative minimum in activity between 9 PM and 2 AM, and then a slight uptick in the early morning hours as a weak disturbance lifts northward across the area from the south/southwest.

STP 09-28-2016: Beautiful Late-September Day

Issue Date: Wednesday, September 28th, 2016
Issue Time: 9:00 AM MDT

Summary:

It’s hard to argue with the weather that played out across Colorado yesterday, as sunny skies and dry conditions created a picture-perfect day. A few high-level clouds pushed into southwestern Colorado during the late evening/overnight hours, but that was the most that Mother Nature could muster. No precipitation fell anywhere across the state, so I hope everyone was able to get outside and enjoy the day, if even for only a few minutes.

20160928_stpimage
Storm Total Precip Legend

FTB 09-27-2016: Another Pleasant Day Ahead

Issue Date: 9/27/2016
Issue Time: 9:10 AM

NO FLOOD THREAT IS FORECAST.

An upper-level ridge and dry air (see IPW chart) will remain in charge of the forecast during this forecast period, leaving Colorado with another beautiful, early-Fall day. Underneath mostly sunny skies, temperatures will climb to above-average values statewide, pushing into the mid-80s for some locations across the eastern plains. For towns/communities across the High Country, temperatures will range from the high 50s to the lower 70s. A few mid-/high-level clouds will drift into southwestern Colorado later tonight due to moisture circulating around the upper-level low currently centered over the Baja Peninsula. That will be the most Mother Nature has to offer during this forecast period.

ipw_20160927

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below (hover over threat areas for more details). For Zone-Specific forecasts, jump below the map.

Flood Threat Legend

Zone-Specific Forecasts

Urban Corridor, Palmer Ridge, Northeast Plains, Raton Ridge and Southeast Plains:

Sunny skies and late-September warmth will be the name of the weather game today, with high temperatures in the 70s and 80s across the area. Overnight lows will be a few degrees warmer than last night, owing to the better warming taking place this afternoon.

Front Range, Southeast Mountains, Northern Mountains, Northwest Slope, San Juan Mountains, Southwest Slope, San Luis Valley, Central Mountains, and Grand Valley:

Mostly sunny skies and pleasant temperatures will be the weather story today. A few high-level clouds will be present during the afternoon, with the introduction of additional mid-/high-level clouds later tonight/overnight for southwest Colorado. A few streaks of virga may be present over the higher terrain of the Southwest Slope and San Juan Mountains regions late this afternoon and during the evening hours, but that will be it.