Issue Date: Monday, June 6th, 2022
Issue Time: 10:50AM MDT
— A LOW flood threat has been issued for portions of the Northwest Slope, Northern Mountains, southern Urban Corridor, Palmer Ridge, Northeast Plains & Southeast Plains
— Fire-Burn Forecast Summary: 2 burn areas under MODERATE threat, 5 burn areas under LOW threat; click HERE for more info
A lot is happening in our synoptic setup today with several ingredients coming together for widespread precipitation this afternoon and into the overnight hours. Marked in the water vapor imagery below is the next shortwave (orange “X”, Montana) and some mid-level energy associated with an incoming jet streak (orange dashed). As the shortwave moves east today, a strong jet streak is also forecast move over the northern tier of the state. Both the right entrance of the jet streak and the additional mid-level energy moving through the flow should help spark numerous rounds of widespread showers and thunderstorms over the mountains and elevated ridges early this afternoon. Increasing westerly steering flows are expected to push this activity into the adjacent eastern plains with ongoing precipitation possible overnight into tomorrow morning over the eastern plains.
Taking a look at moisture, PW at Denver has increased to 0.67 inches with a peak in moisture just under the 500mb level. PW has also increased over western Colorado with moisture advection from the incoming shortwave, and morning values at Grand Junction were measured at 0.68 inches with a notable change in dew point from yesterday. Again, most of this moisture in the mid-levels, meaning initially scattered storms that develop will not be very efficient at accumulation. Nonetheless, numerous rounds of scattered storms will help moisten the boundary layer and increase precipitation accumulation over western Colorado, the mountains, and immediate adjacent plains today. A couple of rounds of thunderstorms and heavier precipitation is anticipated over the elevated terrains of the Northwest Slope and Northern Mountains, which may cause isolated mud flows and debris slides. A LOW flood threat has been issued for this reason.
Over the eastern plains, after yesterday’s convection (orange “X”, Kansas), there are some high dew points over the area (green dashed line). This nice influx of higher surface moisture should continue to move back to the west; however, it is shallow, so there may be some mixing out of the higher dew points closer to the eastern mountains. A cold front then drops through the state this evening and paired with southeast surface flow over the Southeast Plains and southern Palmer Ridge today, it’s likely that some of this higher surface moisture will be able to hang on. While there are fairly quick steering flows forecast today, which will limit the rainfall accumulation from any one storm, training storms will be possible over the Palmer Ridge helping to help boost local accumulations. So, a LOW threat has been issued for this reason. Additionally, storms that track into the Southeast Plains this afternoon as well as those that potentially are sustained overnight may cause local, heavy rainfall as well as severe hail and strong outflow winds. Therefore, a LOW flood threat has also been issued for the Southeast Plains.
Today’s Flood Threat Map
For more information on today’s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.
Zone-Specific Forecasts:
Palmer Ridge, Urban Corridor, Northeast Plains & Southeast Plains:
Training storms and a high moisture environment will cause a LOW flood threat to be issued that persists into the overnight night hours for the Southeast Plains. Back to the west, training storms may produce 1-2 hour totals up to 1.25 inches. Over the eastern plains, max 1-hour rain rates up to 1.75 inches are possible. A severe storm or two may also be possible with the main threats being severe hail and strong outflow winds. If storms linger into the overnight hours over the plains, storm totals up to 2.75 inches will be possible. Flood threats include road flooding, field ponding and rises in local streams/creeks.
Primetime: 1:30PM to 4AM
Front Range, Northern Mountains, Central Mountains & Northwest Slope:
Scattered thunderstorms return to the forecast with training storms causing locally higher totals, especially over the Northwest Slope and Northern Mountains. Max 30-min rain rates up to 0.75 inches with 1-2 hour totals up to 1.10 inches will be possible. A LOW flood threat has been issued, and flood threats include mud flows and debris slides as well as rises in local creeks.
Primetime: 1PM to 8PM
Southeast Mountains, Raton Ridge, San Luis Valley, Southwest Slope, Grand Valley & San Juan Mountains:
These regions should remain mostly dry today, although weak, isolated storms may develop over the Southeast and San Juan Mountains this afternoon. Max 1-hour rain rates up to 0.25 inches may be possible (most likely east). Additional isolated storms may develop over the eastern Raton Ridge with max 1-hour rain rates up to 0.70 inches. Flooding is NOT expected.
Primetime: 2:30PM to 8PM
